Progress 10/01/09 to 09/30/14
Outputs
Target Audience: I have been investigating medicinal components, in particular antioxidants, of plants and foods, and my publications in this area have continued to receive considerable attention among manufacturers of heath foods and functional foods in US, in particular in California. Also, many commodity groups and organizations associated with food and nutrition, such as the California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. In addition, many universities who teach functional foods using information from my research. Changes/Problems: Alternative medicines prepared from natural origins are currently pressing needs because they do not cause any side effects. These area should be receive more attentions in the future. What opportunities for training and professional development has the project provided? The results obtained in this project have provided significant information to food industries manufacturing medicinal foods. Also, medical doctors were interested in the medicinal activities of broccoli sprouts components. How have the results been disseminated to communities of interest? The results from my project have attracted considerable attention among manufacturers of heath foods and functional foods in US, in particular in California. Also, many commodity groups and organizations associated with food and nutrition, such as the California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. What do you plan to do during the next reporting period to accomplish the goals? The investigation will continue to find the way to isolate these biologically active components.
Impacts
What was accomplished under these goals?
It was proved that broccoli sprouts have potent antioxidants to be a valuable source of health foods. Broccoli sprouts have a short harvest time (2 weeks) and are relatively easy to product. Therefore, broccoli sprouts could be a good source for natural antioxidants.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2014
Citation:
Hae Won Jang, Joon Kwan Moon, Takayuki Shibamoto, Analysis and Antioxidant activity of Extract from Broccoli (Brassica oleracea L.) Sprout. J. Agric. Food Chem. 2015. In Press.
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: I have been investigating medicinal components, in particular antioxidants, of plants and foods, and my publications in this area have attracted considerable attention among manufacturers of heath foods and functional foods in US, in particular in California. Also, many commodity groups and organizations associated with food and nutrition, such as the California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. Changes/Problems: Alternative medicines prepared from natural origins are currently pressing needs because they do not cause any side effects. These area should be receive more attentions in the future. What opportunities for training and professional development has the project provided? The results obtained in this project have provided significant information to pharmaceutical industries manufacturing medicinal foods containing mushroom components. Also, medical doctors were interested in the medicinal activities of mushroom components. How have the results been disseminated to communities of interest? The results from my project have attracted considerable attention among manufacturers of heath foods and functional foods in US, in particular in California. Also, many commodity groups and organizations associated with food and nutrition, such as the California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. What do you plan to do during the next reporting period to accomplish the goals? The investigation will continue to find the way to isolate these biologically active components.
Impacts
What was accomplished under these goals?
The mushroom, Trametes versicolor is commonly used as a traditional Chinese medicine and is known to exhibit various biological activities. However, its antioxidant activity has remained unknown. In this project, various extracts obtained from the Trametes versicolor mushroom exhibited strong antioxidant activity and anti-flammatory activity. These results would be applied to prepare alternative medicines.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Kamiyama, M.; Horiuchi, M.; Umano, K.; Kondo, K.; Otsuka, Y.; Shibamoto, T. Antioxidant/anti-inflammatory activities and chemical composition of extracts from the mushroon Trametes versicolor. Int. J. Nutr. Food Sci. 2013, 2, 8391.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Diabetes mellitus is characterized as a consequence of a genetically based disorder and dietary indiscretion also known as diabetes type 2. Diabetes mellitus is a chronic metabolic disease that has a significant impact on health, quality of life, and life expectancy. Recently, an increase in patients with adult diseases, including diabetes, has become a serious problem in advanced countries. In the year 2010, the prevalence of diabetes in children and adults was estimated to be 25.8 million in the US, which is about 8.3% of the population. It has been presumed that oxidative stress in the body is one of the serious contributors to the occurrence of type 2 diabetes. Oxidative damages reportedly cause diabetes. Therefore, antioxidants must play an important role in the prevention of diabetes' occurrence. Our ongoing research, directed at locating natural antioxidants, has continued to be popular among researchers from diverse areas, including researchers studying medicinal plants. In the present study, the antioxidant activity of G. sylvestre leaf was examined to investigate the role of antioxidants in diabetes. G. sylvestre leaf extract was also analyzed by LC/MS to identify possible components with antioxidant and anti-diabetic activity. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: I have been investigating medicinal components, in particular antioxidants, of plants and foods, and my publications in this area have attracted considerable attention among manufacturers of heath foods and functional foods in California. Also, many commodity groups and organizations associated with food and nutrition, such as the California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. Moreover, information obtained from my studies have continually been incorporated into updating my lectures for ETX 128 "Food Toxicology." PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Diabetes mellitus, which is associated with oxidative damage, has a significant impact on the health, quality of life, and life expectancy system. The leaves of G. sylvestre are reported to lower blood sugar, stimulate the heart, uterus, and circulatory systems as well as to exhibit anti-sweet and hepatoprotective activities. Recently, this leaf extract also demonstrated a potential hypoglycemic and subsequent blood cholesterol lowering property in streptozotocin-induced diabetic rats. The ethanol extract of Gymnema sylvestre leaf was examined in vitro and in vivo to investigate the effects of its constitutent antioxidants on diabetic rats. The extract exhibited strong antioxidant activity in TBA (56%), SOD-linked (92%), DPPH (56%), and ABTS (54%) assays. Blood glucose levels in the diabetic rats fed G. sylvestre extract decreased to normal levels. The presence of antihyperglycemic compounds, gymnemagenin and gymnemic acids in G. Sylvetre extract was recognized by LC/MS analysis. Lipid peroxidation levels were decreased by 31.7% in the serum, 9.9% in the liver, and 9.1% in the kidney in the diabetic rats fed with the extract. Feeding G. Sylvestre extract to the diabetic rats decreased the activity of glutathione peroxidase in cytosolic liver and glutamate pyruvate transaminase in serum to normal levels. The use of traditional medicine and medicinal plants in developing countries is increasingly popular as an alternate to western biomedicine to treat various diseases, including diabetes. It has long been known that oxidative damages are associated with a number of disease processes, including diabetes mellitus. In the present study, the extract from G. sylvestre leaf exhibited potent antioxidant activities and increased the activity of beneficial enzymes for the prevention of diabetes.
Publications
- Kang, M.-H.; Lee, M. S.; Choi, M.-K.; Min, K. S.; Shibamoto, T. Hypoglycemic activity of gymnema sylvestre extracts on oxidative stress and antioxidant status in diabetic rats. J. Agric. Food Chem. 2012, 60, 2517-2524.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Since the beginning of recorded history, medicinal plants have been used to treat various diseases. Even after the development of modern medicines, traditional herb therapies have been used clinically, especially in China and Vietnam. In the Southeast Asian tropical climates of Vietnam, approximately 2,500 species of exotic plants have been used in folk medicines for their biological activities such as antioxidant and antimicrobial. Antioxdants have been known to prevent occurrence of many diseases including, cancer, liver disease, Alzheimer's disease, arthritis, inflammation,1 diabetes, Parkinson's disease, atherosclerosis, and AIDS, as well as aging. Recently, natural antioxidants found in plants have come to receive attention as safe alternatives to western biomedical products. Thus ongoing research for a natural and potent antioxidant has become very popular among researchers from diverse areas, including natural plant chemists, food chemists, biologists, and biochemists as well as medical doctors. In the present study, the antioxidant activity of medicinal plants grown in Vietnam was investigated in a search for possible sources of natural antioxidants. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: I have been investigating medicinal components, in particular antioxidant, of plant and food, which have received much attention among manufacturers of heath food and functional food in California. Also, many commodity groups and organizations associated with food and nutrition, such as California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. PROJECT MODIFICATIONS: Previous studies focused on the non-volatile constituents of plants. However, plants also contain numerous volatile chemicals, which have been widely used in both folk medicine and aromatherapies. This study encourages researcher to give more attentions toward medicinal volatile chemicals present in plant and food.
Impacts
Medicinal plants have been used to treat various diseases since ancient times. Their specific activities, such as antioxidant, anti-inflammatory, and anti-cancer, have been studied intensively. In particular, plants grown in Vietnam have attracted considerable attention among food chemists as ideal sources of natural medicinal chemicals. The methanol extracts from three edible Vietnamese-grown plants - Tram, Voi, and Gac tested with the DPPH assay was 91.7 plus or minus 0.4 percent, 63.4 plus or minus 0.7 percent, and 3.7 plus or minus 0.1 percent, respectively. Malonaldehyde/gas chromatography assay also exhibited strong antioxidant activities at the levels of 25 ug mL minus1 in Tram and Voi (95.5 plus or minus 0.3 percent and 78.5 plus or minus 1.4 percent, respectively). These results were also confirmed by thiobarbituric acid assay. The antioxidant activities corresponded positively with the level of total phenolics in all plants. Tram exhibited dose response-related lipoxygenase inhibitory activity, which was observed at 74.2 plus or minus 3.1 percent at 5.0 ug mLminus1, 62.0 plus or minus 0 percent at 0.5 ug mLminus1, and 3.0 plus or minus 1.5 percent at 0.05 ug mLminus1. Conversely, Voi and Gac showed negative anti-lipoxygenase activity. The antioxidant, anti-inflammatory activities and total phenolic contents of the three edible plants grown in Vietnam revealed that they are good sources of supplements for human health. The results obtained in the present study demonstrate the wide range of antioxidant/anti-inflammatory activities of natural plants, suggesting that various other factors, such as the many constituents in the plants, may need to be investigated in order to account for the differences in these activities. The volatile oil constituents and their respective amounts in the plant essences may affect the biological activities, including antioxidant and anti-inflammatory of the plant. Therefore, identification and characterization of the active components in these plants is needed in order to assess the efficacy, as well as safety, of medicinal plants.
Publications
- Sone, Y.; Moon, J.-K.: Mai, T. T.; Thu, N. N.; Asano, E.; Yamaguchi, K.; Otsuka, Y.; Shibamoto, T. Antioxidant/anti-inflammatory activities and total phenolic content of extracts obtained from plants grown in Vietnam. J. Sci. Food Agric. 2011, 91, 2259-2264.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Essential oils, which are odorous essences, are obtained from various natural plant materials including leaves, fruits, roots, and woods. They have been used widely in various products such as cosmetics, household products, and medicines as well as foods and beverages. Approximately 3,000 essential oils have been identified and about 300 are commercially important. In addition to the above uses, essential oils have been used for aromatherapy since ancient times in various countries, such as China, Egypt, Greece, and Turkey. The long history of the use of essential oils for medicinal purposes strongly suggests that some pharmacologically active components are present in essential oils. Recent studies also suggest the medicinal activity of certain essential oils. The application of essential oils as possible therapeutic agents against disease is gaining attention due to various factors. Growing consumer preferences for inexpensive, natural and traditional medicines that are also effective on resistant bacterial or viral strains have stimulated investigations into the bioactive properties of essential oils. This work aimed some of the pharmacological actions demonstrated by essential oils and their roles in health - including antioxidant, antiviral, anti-microbial, anticarcinogenic, and anti-inflammatory activities. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: I have been investigating medicinal components, in particular antioxidant, of plant and food, which have received much attention among manufacturers of heath food and functional food in California. Also, many commodity groups and organizations associated with food and nutrition, such as California Armond Board, CDFA Animal Health and Food Safety, and California Nutrition Counsel, are strongly interested in antioxidants in foods and plants. PROJECT MODIFICATIONS: Previous studies focused on the non-volatile constituents of plants. However, plants also contain numerous volatile chemicals, which have been widely used in both folk medicine and aromatherapies. This study encourages researcher to give more attentions toward medicinal volatile chemicals present in plant and food.
Impacts
Twenty-five essential oils were tested for antioxidant and anti-inflammatory activities. The greatest antioxidant effect was obtained by thyme oil (53%) followed by clove leaf oil (52%), and basil oil (49%). Sandalwood oil (16%), bergamot oil (13%), rosemary oil (10%), and bitter orange oil (9%) showed slight antioxidant effects. Angelica seed oil (-94%), rose oil (-33%), and peppermint oil (-27%) had pro-oxidant activity. Aloe vera oil exhibited the greatest anti-inflammatory effect (96%) at a level of 5 g/mL, followed by thyme oil (86%) at a level of 0.5 g/mL, and bergamot oil (85%) at a level of 0.5 g/mL, jasmine oil (47% at 0.5 g/mL), angelica seed oil (44% at 5 g/mL), and rosemary oil (42% at 5 g/mL). Clove leaf oil showed moderate anti-inflammatory activity (33% at 5 g/mL). Chamomile oil showed slight anti-inflammatory activity at 0.5 g/mL but showed strong pro-inflammatory activity at 5 g/mL (-123%). The results obtained suggest that differences in observed pharmacological activities of essential oils may be affected by the composition of the oils' volatile constituents and the testing methods used. The results obtained in the present study demonstrate the wide range of antioxidant/anti-inflammatory activities of essential oils, suggesting that various other factors, such as the many constituents in the essential oils, may need to be investigated in order to account for the differences in these activities. The volatile oil constituents and their respective amounts in the essential oils may affect the biological activities, including antioxidant and anti-inflammatory of the overall essential oil. Therefore, identification and characterization of the active components in these essential oils is needed in order to assess the efficacy, as well as safety, of essential oils.
Publications
- Wei, A.; Shibamoto, T. 2010. Medicinal activities of essential oils: Role in disease prevention. In: Bioactive Foods in Promoting Health, Fruits and Vegetables. Watson, R. R. Preedy, V. R. (Eds).; Elsevier Inc., San Diego, 2010, pp. 59-70. Wei, A.; Shibamoto, T. 2010 Antioxidant/lipoxygenase inhibitory activities and chemical compositions of selected essential oils. J. Agric. Food Chem. 2010, 58, 7218-7225.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Total chlorogenic acids of nine isomers from seven commercial green and roasted coffee beans ranged from 34.43 plus or minus, 1.50 mg/g to 41.64 plus or minus, 3.28 mg/g and from 2.05 plus or minus, 0.07 mg/g to 7.07 plus or minus, 0.16 mg/g, respectively. Methanol/water (7/3) extracts from four commercial green coffee beans roasted at different conditions (230 degrees C, 12 min; 24 degrees C, 14 min; 250 degrees C 17 min; and 250 degrees C, 21 min) were also analyzed for chlorogenic acids. The total chlorogenic acid found in green coffee beans ranged from 86.42 plus or minus, 2.04 mg/g to 61.15 plus or minus, 1.40 mg/g. Total chlorogenic acids present were reduced in accordance with the intensity of roasting conditions. When green beans were roasted at 230 degrees C for 12 min and at 250 degrees C for 21 min, total chlorogenic acid content was reduced to nearly 50 percent and to almost trace levels, respectively. The results indicate that roasting conditions play an important role in chlorogenic acid content in roasted coffee beans. A general correlation between total CQA and pH was observed. PARTICIPANTS: Dr. Joon Kwan Moon, Post doctoral scholar. TARGET AUDIENCES: This study would serve as a useful research tool for a diverse range of backgrounds for scientists, including biologist, biochemists, chemists, dietitians, food scientists, nutritionists, pharmacologists, and toxicologists as well as medical doctors, from academic instituteions, governmental agencies, and private industries. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The results of the present study suggest that roasting conditions play an important role in the Chlorogenic acid (CQA) content of the final coffee product. It can be estimated that the commercial roasted coffee used in the present study was roasted somewhere between Medium and City roasting conditions. The results of the present study suggest that CQA concentration in roasted coffee, which plays an important role in the quality of brewed coffee taste, influenced by the roasting condition. High CQA content-coffee seems to be better for medicinal purpose. However, acid reflux symptoms may be caused by the acidic components, including CQA, of coffee. Therefore, it is extremely important to prepare coffee, in a way which has low enough levels of CQA to prevent acid reflux yet a sufficient amount for medicinal purposes. In fact, a previous report indicates that 5-CQA, which is the most abundant CQA in coffee, showed moderate antioxidant activity at the level of 10 mg/mL but slight pro-oxidant activity at the level of 100 mg/mL. These results suggest roughly that a CQA content of 50-60 mg/mL in brewed coffee is optimal to expect medicinal activity but not to trigger acid reflux.
Publications
- Moon, J.-K.; Yoo, H. S.; Shibamoto, T. Role of roasting conditions in the level of chlorogenic acid content in coffee beans: Correlation with coffee acidity. J. Agric. Food Chem. 2009, 57, 5365-5369.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: The freeze-dried onion sprout was steam distilled and the distillate was extracted with dichloromethane (volatile sample). Water sample I was obtained from the residual aqueous solution in the extractor. The filtrate and the methanol extract of filtrand from the residual aqueous solution in the steam-distillation flask were named water sample II and methanol sample, respectively. Among the total of 71 components identified in the volatile sample, 24 were sulfur-containing compounds, which comprised 36.87% of the total volatile chemicals identified. The volatile sample inhibited hexanal oxidation for 40 days by over 99% at levels over 100 ug/mL. The volatile sample and water sample II exhibited moderate antioxidant activity in a malonaldehyde/gas chromatography assay and thiobarbituric acid assay, whereas water sample I did not show appreciable activity. The volatile sample, water sample I, and water sample II exhibited anti-inflammatory activity with a dose related response in the lipoxygenase inhibitor-screening assay. PARTICIPANTS: Ms. Mizuho Takahashi, graduate students. She was trained to be a researcher as a MS student. TARGET AUDIENCES: This study would serve as a useful research tool for a diverse range of backgrounds for scientists, including, biologist, biochemists, chemists, dietitians, food scientists, nutritionists, pharmacologists, and toxicologists as well as medical doctors, from academic institutions, governmental agencies, and private industries. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
For thousands of years, the onion (Allium cepa L.), a family of Allium plants, has been used in spices, foods, flavors, and remedies. In addition to the fresh form, onions have been used in various forms, such as a powdered form for a flavor enhancer and a dried form as a seasoning. Due to their characteristic odor and taste, onions (Allium cepa L.) are considered an important flavor ingredient and have been used in a wide variety of dishes all over the world. In addition, onions have also received a great deal of attention due to its medicinal value. The flavor and taste of onion sprouts are quite similar to those of onion. The chemical composition of onion sprout and onion are also similar. These results suggest that onion sprouts can be consumed in the same way as onion. Moreover, it is quite easy to prepare edible onion sprouts. It requires only UV light, water, and less than one week between germination and harvest, suggesting that onion sprouts can be an excellent food source for people living in sterile areas in the world.
Publications
- Takahashi, M.; Shibamoto, T. Chemical composition and antioxidant/anti-inflammatory activities of steam distillate from freeze-dried onion (Allium cepa L.) sprout. J. Agric. Food Chem. 2008, 56, 10462-10467.
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Progress 01/01/07 to 12/31/07
Outputs
Medicinal plants have been used for many years to treat various diseases even after the development of modern medicines. In particular, traditional Chinese herb medicines, including licorice root, have been clinically used since the beginning of recorded history. Today, over seven thousand herbs have been employed by 80% of the world's population. Licorice root is one of the most important medicinal herbs that have been used in China for over 6,000 years. Numerous medicinal activities and potential health benefits reported in licorice root include antibacterial, anti-ulcer, anti-tumorigenic, anti-atherosclerotic, anti-inflammatory, and antioxidant effects Previous studies focused on the non-volatile constituents of licorice root. However, plants also contain numerous volatile chemicals, which have been widely used in both folk medicine and aroma therapies. Many medicinal volatile compounds may escape into the ambient air during actual preparation of herbal medicines.
It is necessary to find a way to recover such volatile compounds, which may escape with water vapor, during the preparation of herbal medicines.
Impacts
Chinese licorice root was water distilled and the distillate was subsequently extracted with dichloromethane. Residual aqueous solution from the extraction was fractionated using column chromatography. A total of 127 chemicals were identified in the dichloromethane extract, which inhibited hexanal oxidation. A fraction eluted from the residual aqueous solution with acetone exhibited potent antioxidant activities both in a thiobarbituric acid assay and in a malonaldehyde/gas chromatography assay. The acetone fraction also exhibited strong anti-inflammatory activity in a lipoxygenenase inhibitor screening anti-inflammatory assay. Chinese medicinal plant, licorice root, was shown to have numerous health benefits including antibacterial, anti-ulcer, anti-tumorigenic, anti-atherosclerotic, anti-inflammatory, and antioxidant properties. Most common Chinese herb medicinal preparations involve heating the herbs in water, which is eventually evaporated off into the ambient air
to concentrate the herbal water extract. The present study demonstrated that the water distilled from licorice root contains compounds with strong antioxidant and anti-inflammatory activities. Even though the sample preparation method used in the present study is not exactly as same as that used in actual preparation of herbal medicines, the present study suggests that many medicinal compounds escape into the ambient air during preparation. It is necessary to find a way to recover such volatile compounds, which may escape with water vapor, during the preparation of herbal medicines.
Publications
- Wei, A.; Shibamoto, T. Antioxidant activities and volatile constituents of various essential oils. J. Agric. Food Chem. 2007, 55, 1737 through 1742.
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Progress 01/01/06 to 12/31/06
Outputs
Dichloromethane extracts obtained from Maillard model systems consisting of glucose and 8 amino acids were examined for antioxidative activity. The extracts from all 8 model systems inhibited hexanal oxidation by 100% at levels higher than 50 g/ml over 40 days. The extracts from the model systems of glucose/asparagine, histidine, or tryptophan inhibited hexanal oxidation by 100% at the level of 10 g/ml of extract over 40 days. Seven column chromatographic fractions from the extract of a glucose/asparagine model system inhibited hexanal oxidation by 100% at levels higher than 10 g/ml over 40 days. The fraction eluted with ethyl acetate inhibited hexanal oxidation by 100% at the level of 2 g/ml over 40 days. 2-Furanmethanol, which has antioxidative activity, was found at a level of 0.022 mg/ml. 2,3-Diydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (pyranone), which may abstract a hydroxyl radical, was found at a level of 7.28 mg/ml in this
fraction.
Impacts
The discovery of potent antioxidant, pyranone is significant to explain the formation of antioxidant in cooked foods. Its presence in cooked foods may prevent various diseases associated with oxidative damages.
Publications
- Osada, Y.; Shibamoto, T. Antioxidative activity of volatile extracts from Maillard model systems. Food Chem. 2006, 98, 522-528.
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Progress 01/01/05 to 12/31/05
Outputs
A modified malonaldehyde (MA) assay for antioxidant activity, which involves derivatization and headspace solid-phase microextraction (HS-SPME) was developed and validated. The recovery efficient of MA as 1-methylpyrazole (product of MA and N-methylhydrazine) from a headspace of an aqueous solution containing MA, buffer, surfactant, and cod liver oil using HS-SPME with a PDMS/DVB fiber was 86.7 +- 2.59 %. MA was analyzed by a gas chromatograph with a nitrogen-phosphorus detector and its detection limit was 0.0103 nmol/mL. Antioxidant activities of natural compounds were determined as percentage inhibition of MA formed from cod liver oil oxidized by Fenton's reagents in the above aqueous solution. Sesamol inhibited MA formation most (86.1 %), followed by eugenol (84.4 %), capsaicin (80.7 %), ethylvanillin (45.3 %) and vanillin (31.6 %) at a level of 50 ug/mL. This method did not require any organic solvents, is simple, fast, and a highly sensitive method for MA
determination.
Impacts
The assay did not require any solvent for extraction and vigorous conditions such as low pH and high temperature for derivatization, which is essential for TBA assay, thus it has advantage of less formation of artifacts. The HS-SPME method is simple and applicable for automation, which would provide fast and specific assay for MA. It is suitable for assessing antioxidant activity of complex samples, such as blood and urine as well as food.
Publications
- Fujioka, K.; Shibamoto, T. 2005. Improved malonaldehyde assay using headspace solid-phase microextraction and its application to the measurement of the antioxidant activity of phytochemicals. J. Agric. Food Chem.,53, 4708-4713.
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Progress 01/01/04 to 12/31/04
Outputs
Antioxidative activities of volatile extracts from six teas (one green tea, one oolong tea, one roasted green tea, and three black teas) were investigated using an aldehyde/carboxylic acid assay and a conjugated diene assay. The samples were tested at the levels of 20, 50, 100, and 200 ug/mL of dichloromethane. The results obtained from the two assays were consistent. All extracts except roasted green tea exhibited dose-dependent inhibitory activity in the aldehyde/carboxylic acid assay. A volatile extract from green tea exhibited most potent activity in both assays among the six extracts. It inhibited hexanal oxidation by almost 100% over 40 days at the level of 200 ug/mL. The extract from oolong tea inhibited hexanal oxidation by 50% in 15 days. In the case of the extract from roasted green tea, the lowest antioxidative activity was obtained at the level of 200 ug/mL, suggesting that the extract from roasted green tea contained some pro-oxidants. The extracts from
the three black teas showed slight anti- or pro-activities in both assays. The major volatile constituents of green tea and roasted green tea extracts, which exhibited significant antioxidative activities, were analyzed using gas chromatography/mass spectrometry. The major volatile chemicals with possible antioxidative activity identified were alkyl compounds with double bond(s), such as 3,7-dimethyl-1,6-octadien3-ol (8.04 mg/kg), in the extract from green tea and heterocyclic compounds, such as furfural (7.67 mg/kg), in the extract from roasted green tea. Benzyl alcohol, which was proved to be an antioxidant, was identified both in a green tea extract (4.67 mg/kg) and a roasted tea extract (1.35 mg/kg).
Impacts
Volatile aroma chemicals have been studied from the view point of flavor and fragrances. This study reports antioxidative activity of aroma essences from various teas at the first time in the world.
Publications
- Yanagimoto, K.; Ochi, H.; Lee, K.-G.; Shibamoto, T. Antioxidative activities of volatile extracts from green tea, oolong tea, and black tea. J. Agric. Food Chem. 2003, 51, 7396 through 7401.
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Progress 01/01/03 to 12/31/03
Outputs
Acrylamide formed in browning model systems was analyzed using a gas chromatograph with a nitrogen-phosphorous detector. Asparagine alone produced acrylamide via thermal degradation at the level of 0.52-0.90 ug/g of asparagine. When asparagine was heated with triolein-which produced acrolein at the level of 1.82 +- 0.31 (n = 5) mg/L of headspace by heat treatment-acrylamide was formed at the level of 85.2-92.0.0 ug/g of asparagine. When acrolein gas was sprayed onto asparagine heated at 180 degrees C, a significant amount of acrylamide was formed (114 ug/g of asparagine). On the other hand, when acrolein gas was sprayed onto glutamine under the same conditions, only a trace amount of acrylamide was formed (0.18 ug/g of glutamine). Relatively high levels of acrylamide (753 ug/g of ammonia) were formed from ammonia and acrolein heated at 180 degrees C in vapor-phase. The reaction of acrylic acid, which is an oxidation product of acrolein, and ammonia, produced a high
level of acrylamide (190,000 ug/g of ammonia), suggesting that ammonia and acrolein play an important role in acrylamide formation in lipid-rich foods.
Impacts
Acrylamide can be formed from asparagine alone via thermal degradation, but carbonyl compounds, such as acrolein, promote its formation via a browning reaction.
Publications
- Yasuhara A., Tanaka Y., Hengel M., Shibamoto T. 2003. Gas chromatographic investigation of acrylamide formation in Browning model systems. J. Agric. Food Chem. 51, 3999-4003.
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Progress 01/01/02 to 12/31/02
Outputs
Exhaust gases from the combustion of polyvinyl chloride (PVC), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), and their various mixtures were analyzed for PCDDs, PCDFs, and coplanar PCBs by gas chromatography/mass spectrometry (GC/MS) in order to investigate the role of PVC in these chlorinated compounds. Total amounts of dioxins (PCDDs + PCDFs) found in the samples were 11.7 ng/g PE alone, 1.17 ng/g from PS alone, 25.3 ng/g from PET alone, 448 ng/g from PE with PVC, 140 ng/g from PS with PVC, 126 ng/g from PET with PVC, 824 ng/g from PVC alone under low-CO level, and 8920 ng/g from PVC alone under high-CO level. CO level in high-CO level condition was 880 ppm which was 20 times greater than that in low-CO level condition. Formation of coplanar PCBs ranged from 0.095 ng/g (PE alone) to 77 ng/g (PVC alone under high-CO level). There is a clear correlation between dioxin formation and chloride content. PCDFs composed 80% (PET +PVC) - 98% (PET
alone) of the total dioxins formed in the exhaust gases. The results indicate that PVC contributes significantly to the formation of PCDDs, PCDFs, and coplanar PCBs from mixtures of plastics upon combustion.
Impacts
Formation mechanisms of highly toxic dioxins are presented. The formation of dioxins from public incinerators can be minimized using the results of this study.
Publications
- Katami, T., Yasuhara, A., Okuda, T., Shibamoto, T. Formation of PCDDs, PCDFs, and Coplanar PCBs from Polyvinyl Chloride during Combustion in an Incinerator. Environ. Sci. Technol. 2002, 36, 1320-1324.
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Progress 01/01/01 to 12/31/01
Outputs
Typical volatile heterocyclic compounds found in brewed coffee extracts-pyrroles , furans, thiophenes, and thiazoles-were examined for antioxidative activity which was determined by measuring the oxidative conversion of hexanal to hexanoic acid using gas chromatography. 2-Acetylpyrrole, 1-methylpyrrole, and pyrrole inhibited hexanal oxidation by 98%, 87%, and 78%, respectively, at a concentration of 500 ug/mL over a period of 30 days. 2-Methylfuran, which inhibited hexanal oxidation by 90% at all concentrations tested (500, 200, 100 ug/mL) for 30-day period, exhibited the greatest activity among furans tested. Similarly, 2-methylthiophene, which inhibited hexanal oxidation by almost 100% at a concentration of 500 ug/mL over 30 days, exhibited the greatest activity among the thiophenes tested. In general, thiazoles were ineffective antioxidants at all concentrations tested. However, 4,5-Dimethylthiazole was able to inhibit hexanal oxidation by 50% at the highest level
tested (500 ug/mL). 2-Acetylpyrrole, 2-methylfuran, and 2-methylthiophene at concentrations of 500-200-100 ug/mL and furan at a concentration of 500 ug/mL, exhibited comparable antioxidative activity to the synthetic antioxidant BHT at a concentration of 50 ug/mL.
Impacts
(N/A)
Publications
- Fuster, M. D., Mitchell, A. E., Ochi, H., Shibamoto, T. Antioxidative Activities of Heterocyclic Compounds Formed in Brewed Coffee. J. Agric. Food Chem. 2000, 48, 5600-5603.
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Progress 01/01/00 to 12/31/00
Outputs
Fates of carcinogenic pesticides prothiofos and cyanophos found in Janapese apple-pears was investigated. Bags impregnated with the organophosphorus pesticides prothiofos and cyanophos at three levels were used to cover Japanese apple-pears to protect them from insects. The total amounts of prothiofos residue in the three bags collected four months after application ranged from 0 to 37% of the amounts (81, 148, 333 mg) found in the bags prior to a bagging. The total amounts of cyanophos residue in three bags collected four months after application ranged from 11% to 29% of the amounts (335, 2860, 3740 mg) present prior to a bagging. Amounts of prothiofos found in fruits after four months ranged from 0 to 0.076 ppm. Amounts of cyanophos found in fruits after four months ranged from 0 to 0.011 ppm. Results of the present study indicate that these two pesticides migrated from pesticide-impregnated bags to fruits during the growing season.
Impacts
(N/A)
Publications
- Katami, T., Nakamura, M., Yasuhara, A., Shibamoto, T. 2000. Migration of organophosphorus insecticides cyanophos and prothiofos residues from impregnated paper bags to Japanese Apple-Pears (Pyrus pyrifolia Nakai Cv.Nijisseiki). J. Agric. Food Chem. 2000, 48, 2499 2501
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Progress 01/01/99 to 12/31/99
Outputs
Recently numerous studies on biological active substances, such as antioxidants, formed by nonenzymatic browning reactions (more generally amino-carbonyl reactions) including cooking have been reported. Volatile compounds, in particular heterocyclic flavor chemicals found to protect against oxidative damage of lipids, that is associated with many diseases including cancer, arteriosclerosis, aging, and immune deficiency. The headspace volatiles collected from corn oil heated with glycine inhibited the oxidative process from aldehyde to carboxylic acid. The antioxidative strength of 1-methylpyrrole found in the above headspace was comparable to that exhibited by a-tocopherol. Chemicals such as imidazoles isolated from a glucose/cysteine Maillard model system inhibited hexanal oxidation by 100% over 110 days. In addition, dichloromethane extract of brewed coffee and many flavor compounds found in brewed coffee inhibited the oxidative conversion of hexanal to hexanoic
acid. Dichlomethane extracts of beer also possessed inhibitory effect to oxidation of hexanal. These recent studies clearly indicated that some volatile flavor chemicals posses an antioxidative activity.
Impacts
(N/A)
Publications
- Singhara, A., Macku, C., and Shibamoto, T. 1998. Antioxidative activity of brewed coffee extracts. In Functional Foods for Disease Prevention II: Medicinal Plants and Other Foods. ACS Symposium Series 701, ACS, Washington, DC, pp 101-109.
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Progress 01/01/98 to 12/01/98
Outputs
Volatile compounds formed in headspace of menhaden fish oil heated with cysteine or cysteine and trimethylamine oxide (TMAO) were analyzed by gas chromatography and gas chromatography/mass spectrometry. Among over 150 gas chromatographic peaks, 105 compounds were positively identified. Among the 45 compounds identified in the headspace of heated fish oil without TMAO or cysteine, the major compounds identified were aldehydes. When fish oil was heated with cysteine, the number of volatiles formed increased (77 compounds identified) and the addition of TMAO further increased the number of volatiles formed (87 compounds identified). The major compounds identified were heterocyclic compounds: 8 furans, 8 pyridines, 1 pyrrole, 4 thiazoles, 3 thiazolines, and 2 thiophenes. TMAO acted as a promoter of the oxidative degradation of fish oil and cysteine rather than as a reactant for the nitrogen sources. The heterocyclic compounds identified are believed to contribute to the
flavor of cooked fish.
Impacts
(N/A)
Publications
- HORIUCH M., UMANO K. and SHIBAMOTO T. 1998. Analysis of volatile compounds formed from fish oil heated with cysteine and trimethylamine oxide. J Agric Food Chem 46: 5232-5237.
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Progress 01/01/97 to 12/01/97
Outputs
There have been may reports on the toxicity of volatile aldehydes over the last decade. In one instance, squamous cell carcinoma in the nasal cavity of rats resulted from repeated inhalation of formaldehyde. Acetaldehyde is also capable of inducing nasal carcinomas in experimental animals. According to the technical support document prepared by the California Environmental Protection Agency/Air Resources board, ambient acetaldehyde is an air pollutant which may cause or contribute to an increase in mortality or serous illness, or which may pose a present or potential hazard to human health based on the results of risk assessment. N-Saturated aldehydes (formaldehyde, acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal, and nonanal) formed in ambient air from heated fish flesh (herring, mackerel, sardine, and squid) were analyzed using a gas chromatograph. Formaldehyde and acetaldehyde generally made up the largest quantities of aldehydes recovered.
Volatile compounds formed from heated menhaden fish oil with or without trimethylamine oxide (TMAO) were also analyzed. Major compounds formed in headspace of heated fish oil without TMAO were aldehydes including n-C1-C10 saturated aldehydes and some branched aldehydes. Formation of these toxic aldehydes from cooking lipid-rich foods may cause some adverse effect to humans.
Impacts
(N/A)
Publications
- SHIBAMOTO T. and HORIUCH M. 1997. Role of aldehydes in cooked fish flavors. In: Flavor and Lipid Chemistry of Seafoods. ACS Symposium Series 674, ACS, Washington, D.C. pp. 20-30.
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Progress 01/01/96 to 12/30/96
Outputs
The chemical pathways between amines and reducing sugars lead to a complex mixture of products in processed foods. The Maillard reaction, or nonenzymatic browning, is a set of reactions responsible for providing cooked foods with their color, flavor and aroma. In addition, Maillard reaction products have also been investigated for nutritional, physiological and biological activities. The process and products of Maillard reaction have been implicated in a wide variety of diseases such as diabetes and cancer, and pathological conditions such as aging. The studies using Maillard reaction products indicated that the Maillard reaction is responsible for the formation of mutagenic compounds in cooked foods. The diversity of the mutagens ranges from simple dicarbonyl compounds and heterocyclic volatiles to heterocyclic aromatic amines. the advanced analytical developments and genotoxic testing techniques used to identify and quantify such compounds in foods and to assess
their mutagenicity have provided information to establish relationships between dietary intake and carcinogenesis.
Impacts
(N/A)
Publications
- WONG, J.W. and SHIBAMOTO, T. 1996. Genotoxicity of maillard reaction product. In: The Maillard Reaction: Consequences for the Chemical and Life Sciences. R. Ikan, Ed. John Wiley & Sons, New York, pp 129-159.
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Progress 01/01/95 to 12/30/95
Outputs
Volatile products formed in cooked foods posses various biological and chemical properties. Volatile products prepared from a simulated cooking system consisting of D-glucose/L-cysteine and related heterocyclic compounds were evaluated for antioxidative activity, measured by the oxidation of hexanal to hexanoic acid either in the dark or in sunlight. In the case of the experiments in the dark, the volatile browning reaction mixture inhibited hexanoic acid formation by almost 100% for up to 13 days. Some column chromatographic (CC) fractions of the above reaction mixture exhibited activities comparable to that of whole samples. Imidazole, 2-thioimidazole, and 2-methyl-3-furanthiol exhibited some inhibitory activity. In the case of the experiments in sunlight, the reaction mixture and some CC fractions exhibited satisfactory inhibition, whereas some CC fractions showed prooxidative activity. Mixtures of some heterocyclic compounds behaved either as an antioxidant or as a
proxidant after 75 days.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
Reports on the toxicity of volatile aldehydes over the last decade have shown squamous cell carcinoma in the nasal cavity of rats resulted from repeated inhalation of formaldehyde. Acetaldehyde can induce nasal carcinomas in experimental animals. Ambient acetaldehyde is an air pollutant which may cause or contribute to an increase in mortality or serious illness, or which may pose a present or potential hazard to human health based on the results of risk assessment. Because people are exposed to many different vapors formed from cooking foods, it is important to determine the details of the formation of suspected toxicants, such as formaldehyde, formed during cooking. Volatile aldehydes (formaldehyde, acetaldehyde, propanal, isobutanal, butanal, isopentanal, pentanal, hexanal, heptanal, octanal, nonanal) formed in a headspace from various kinds of fish flesh during heat treatment were collected in a cysteamine solution. Aldehydes derivatized to corresponding
thiazolidines were analyzed by a gas chromatograph with nitrogen-phosphorus detector. Amounts of formaldehyde found ranged from 0.48 to 5.31 ug/g fish flesh and amounts of acetaldehyde found ranged from 1.70 to 15.47 ug/g fish flesh. These two highly volatile aldehydes generally made up the largest quantities of aldehydes. The total aldehydes (except formaldehyde and acetaldehyde) formed ranged from 1.06 to 51.09 ug/g fish flesh.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
Glyoxal, methylglyoxal (MG), malonaldehyde (MA), acrolein, formaldehyde, acetaldehyde, and propanal formed from squalene, cod liver oil, ethyl esters of fatty acids, and volatile aldehydes upon UV irradiation were derivatized to nitrogen- or sulfur-containing compounds. Derivatives were analyzed by a gas chromatograph equipped with a nitrogen-phosphorus detector or a flame photometric detector. Maximum amounts of glyoxal (9.6 nmol/mg) and MG (14 nmol/mg) formed from squalene after 10 h of UV irradiation. Cod liver oil also produced glyoxal (27 nmol/mg) and MG (5.7 nmol/mg). Glyoxal was formed at concentrations of 10 nmol/mg from ethyl linolenate, 32 nmol/mg from ethyl linolenate, and 50 nmol/mg from ethyl arachidonate. MG was also formed from the ethyl esters of fatty acids. MA and acrolein were formed from squalene, cod liver oil, and ethyl esters of fatty acids under the same conditions. Glyoxal and MG were produced from acetaldehyde, acrolein, and propanal in the
range from 2 to 9 nmol/mg. Prior to this study, glyoxal and MG had never been reported as photodegradation products of lipids or fatty acids.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
The mutagenic fatty aldehydes formed from heated corn oil and from several corn oil/glycine mixtures were collected by a dynamic headspace sampling method and subsequently reacted with cysteamine to yield corresponding thiazolidines. Derivatized aldehydes were analyzed by a capillary gas chromatograph with flame photometric detector. Six fatty aldehydes, including mutagenic formaldehyde and acetaldehyde, decreased in concentration in relation to increasing amounts of glycine in the oil.
Impacts
(N/A)
Publications
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Progress 01/01/91 to 12/30/91
Outputs
Aqueous fresh and frozen solutions of ethyl arachidonate, ethyl linolenate, and ethyl linoleate were exposed to microwave and thermal heating to induce lipid peroxidation. Carcinogenic malonaldehyde and formaldehyde were derivatized to 1-methyl pyrazole with N-methylhydrazine and to thiazolidine with cysteamine, respectively, and were then determined by capillary gas chromatography with a nitrogen-phosphorous detector. For both heating methods, the malonaldehyde concentration depended on the degree of unsaturation in the fatty acid. The samples containing arachidonate produced the most malonaldehyde (7.8-11.2 nmol/mg), followed by those containing linolenate (2.9-5.3 nmol/mg) and linoleate (0.7-1.7 nmol/mg). There were no significant differences in the amount of malonaldehyde formed between the heating methods for both fresh and frozen solutions. Ethyl arachidonate and ethyl linolenate produced about the same amount of formaldehyde (5.8-10.4 nmol/mg), whereas
ethyl linoleate produced slightly less (3.2-5.3 nmol/mg) formaldehyde.
Impacts
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Publications
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Progress 01/01/90 to 12/30/90
Outputs
The mutagenic or carcinogenic lipid peroxidation products formed from some fattyacids and their esters upon Fe2=/H202 exudation were analyzed by two derivatization methods. alpha, beta-unsaturated aldehydes and beta-dicarbonyl compounds were derivatized with N-methylhydrazine. Saturated normal aldehydes were dervatized with cysteamine. Subsequently, a specific quantity of each derivative 1-methylphrazoline, 1-methylpyrazole, and thiazolidine was analyzed by gas chromatography. Formaldehyde, which has never been quantified satisfactorily in a lipid peroxidation system, was the major product, and its quantities ranged from 142 nmol/mg in ethyl linoenate to 50 nmol/mg in ethyl arachidonate. Malonaldehyde was found in all samples, in levels between trace in oleic acid and 97 nmol/mg in ethyl arachidonate. 4-Hydroxy-2-nonenal was found in arachidonic and linoleic acids and their ethyl esters, whereas 4-hydroxy-2-nonenal was found in arachidonic and linoleic acids and their
ethyl esters. Hexanal was one of the main aldehydes formed from arachidonic acid (43 nmol/mg) and linoleic acid (141 nmol/mg) and from their ethyl esters, but propanal was produced in significant amounts only from linoleic acid and its ethyl ester (35 and 23 nmol/mg, respectively).
Impacts
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Publications
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Progress 01/01/89 to 12/30/89
Outputs
A gas chromatographic method was developed to determine levels of toxic formaldehyde and acrolein formed from food by cooking. A new method for the determination of trace levels of formaldehyde and acrolein in air was developed and validated. The method is based on the reaction of formaldehyde with cysteamine to form thiazolidine and acrolein with N-methylhydrazine to form 1-methyl-2-pyrazoline. Derivatives were determined by gas chromatography with a fused silica capillary column and a nitrogenphosphorus detector (NPD). The lowest detection level for thiazolidine was 17.2 pg, equivalent to 5.80 pg of formaldehyde. The recovery efficiency of trace gas phase formaldehyde in air was over 90%. Formaldehyde levels in ambient laboratory air were 48.9 - 56.2 ppb (v/v). The detection limit of 1-methyl-2-pyrazoline with the NPD was 8.9 pg, equivalent to 5.9 pg of acrolein. The recovery efficiencies of vapor-phase acrolein were 98.0 +/ 2.9% and 100.3 +/ 3.1% for 150 micro
gm and 15 micro gm, respectively.
Impacts
(N/A)
Publications
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Progress 01/01/88 to 12/30/88
Outputs
N-Nitrosothiazolidine, which has been reported to be mutagenic, is a nitrosaminerecently found in many smoke-cured meats such as bacon. The biological fate of N-nitrosothiazolidine was studied during this reporting period. 2-(superscript 14)C-N-nitrosothiazolidine was synthesized. Rats, given 125 mg/kg 2-(superscript 14)C-N-nitrosothiazolidine by gavage, excreted 81% of the administered (superscript 14)C into the urine and 7% as (superscript 14)CO(subscrip The primary urinary metabolite was 2-hydroxythiazolidine. Smaller amounts of 4- and/or 5-hydroxy-thiazolidine were also detected. The determination of hydroxythiazolidine indicated that (alpha)-hydroxylation and denitrosation are major metabolic pathways of N-nitrosothiazolidine.
Impacts
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Publications
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Progress 01/01/87 to 12/30/87
Outputs
Soy sauce treated with 2000 ppm nitrite alone or with broccoli, tofu or ascorbate were heated at 80C for 30 min under acidic conditions. The reaction products extracted with dichloromethane were fractionated into 24 fractions by silica gel column chromatography. Both the extract and the fractions were tested for mutagenicity using the Ames Salmonella/microsome preincubation assay. The fractions exhibiting potent mutagenic effect were analyzed by gas chromatography. The extracts of the seven nitrite-treated soy sauce mixtures were mutagenic to the Salmonella/typhimurium tester strains TA98 and TA100 with or without S9 mix. The addition of broccoli, tofu or ascorbate reduced mutagenicity of the extracts. The addition of broccoli changed significantly the mutagenic patterns of the fractions obtained from an extract. The GC/FID chromatograms indicated that the mutagenic fractions had certain peaks with same retention time but identification of those peaks has not yet
been completed.
Impacts
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Publications
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Progress 01/01/86 to 12/30/86
Outputs
Vapour formed from overheated decaffeinated coffee was collected and tested for mutagenicity using the Ames assay with Salmonella/typhimurium strains TA98 and TA100. Vapour produced at 73C and 100C exhibited no mutagenicity. The basic fraction of vapour produced at 350C showed weak mutagenicity toward strain TA98 with metabolic activation. Chemical analysis of this fraction identified pyridines and pyrazines as the major constituents. None of the compounds identified in this fraction have been reported as mutagenic when tested in the Ames assay. The amounts of acrolein formed from heated cooking oils and from beef fat were determined as a morpholine derivative. Headspace volatiles formed from cooking oils or beef fat heated at various temperatures were purged into an aqueous morpholine solution with either a nitrogen or an air stream. Morpholinopropanal produced from acrolein and morpholine was extracted with dichloromethane and subsequently analyzed by a gas
chromatograph equipped with a thermionic detector and a fused silica capillary column. Five cooking oils and beef fat were separately heated at 300C for 2 hours, and each acrolein formed was analyzed. The amount of acrolein formed from 120 g samples ranged from 30 mg (soybean oil) to 72 mg (olive oil).
Impacts
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Publications
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Progress 01/01/85 to 12/30/85
Outputs
Trace quantities of carcinogenic formaldehyde and methyl glyoxal in aqueous and food samples were determined by a newly developed method. Formaldehyde and methyl glyoxal were reacted with cysteamine in aqueous medium or food sample to give thiazolidine and 2-acetylthiazolidine, respectively, at pH 6 and 8. Thiazolidine derivatives formed from formaldehyde and methyl glyoxal were extracted with dichloromethane or chloroform and subsequently analyzed by a gas chromatograph equipped with a fused silica capillary column and a thermionic detector. Seventeen commercial food items were analyzed for formaldehyde and methyl glyoxal. The quantities of formaldehyde and methyl glyoxal varied from 0 to 620 ppm, respectively.
Impacts
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Publications
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Progress 01/01/84 to 12/30/84
Outputs
A browning model system, consisting of diacetyl and ammonia, produced frameshiftand base-pair substitution mutagens when the system was heated over 20 min and 120 min, respectively. The major product was 2,4,5-trimethylimidazole, which showed no mutagenicity toward Salmonella typhimurium strains TA98 and TA100 with or without metabolic activation. When furfural was reacted with nitrate under mild conditions (for 30 min to 3 h at 0-25 C and pH 2-7), it did not produce mutagenic nitrofuran derivatives. However, the ethyl ether extract obtained from the reaction mixture of furfural and nitrate with hydrochloric acid exhibited strong mutagenic activities toward S. typhimurium strains TA98 and TA100 in the presence of metabolic activation. The major product of this reaction mixture, 4-nitrofurfural, exhibited no mutagenicity toward tester strains TA98 and TA100 with or without metabolic activation. Pure active mutagen (S) was (were) not, however, identified in either
system.
Impacts
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Publications
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Progress 01/01/83 to 12/30/83
Outputs
Soy sauce was heated with 100, 500, 1000 or 2000 ppm sodium nitrite for 30 min at 30C and pH 3. The reaction mixtures were extracted with dichloromethane followed by ethyl acetate. After removal of the solvents, the extracts were subjected to analysis (gas chromatograph-thermal energy analyzer and gas chromatograph-mass spectrometer) and Ames mutagenicity texts. N-Nitrosodimethylamine and N-nitrosodiethylamine were found in the dichloromethane extract of the soy sauce treated with 2000 ppm nitrite at levels of 10 and 120 mug/ml, respectively. N-Nitrosoproline was identified in the ethyl acetate extract of the same sample at a level of 0.5 mug/ml. Both extracts exhibited dose-related mutagenicity in Salmonella typhimurium strain TA 100 with S-9 mix. The dichloromethane extract showed much higher mutagenicity than did the ethyl acetate extract. The samples obtained from soy sauce treated with 100, 500 and 1000 ppom nitrite were not mutagenic, but
N-nitrosodiethylamine was detected by thermal energy analysis in the soy sauce treated with 1000 ppm nitrite. The addition of 10,000 ppm L-ascorbic acid, along with 2000 ppm nitrite to soy sauce prevented the formation of mutagenic materials or detectable nitrosamines.
Impacts
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Publications
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Progress 01/01/82 to 12/30/82
Outputs
Methylene chloride extracts of the browning reaction products prepared from model systems consisting of major milk components (casein and/or lactose, and non-fat dried milk) were tested for mutagenicity in the Ames Slamonella/microsome assay. Samples obtained by heating aqueous solutions of these components under either neutral or basic (pH 10) conditions exhibited no significant mutagenic activity when tested with or without S-9 mix. The addition of common food additives, such as sodium nitrite, butylated hydroxyanisole and butylated hydroxytoluene, to the aqueous solutions did not enhance the mutagenic activity of the browning samples. On the other hand, the tar samples prepared by heating the same milk components in the dry state exhibited strong mutagenicity, primarily to Salmonella typhimurium strain TA98 and only with S-9 mix. A casein/lactose mixture and non-fat dried milk were also heated with baking soda in the dry state. The presence of the baking soda
enhanced the mutagenicity of the browning products; the tar from the non-fat dried milk heated with baking soda was the most potently mutagenic of all the samples towards strain TA98 and also produced a positive response in strain TA100 in the presence of S-9 mix.
Impacts
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Publications
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Progress 01/01/81 to 12/30/81
Outputs
Starch, and a mixture of starch and glycine were heated at 290 degrees C for 40 min in flasks. Volatile chemicals produced in these dry reaction systems were entrained on porous polymers (Porapak Q). The samples recovered from the flasks and the Porapak Q traps by methylene chloride extraction were subjected to the Ames Salmonella typhimurium reversion assay. The samples from the starch-glycine system showed distinct dose-related mutagenic activities toward S. typhimurium strain TA 98 with metabolic activation (S-9 mix) both in agar-incorporation and preincubation assays. Samples from the starch alone did not show any mutagenic activity toward S. typhimurium strain TA 98 or TA 100 with or without S-9 mix. All of the samples were toxic to the bacteria under certain conditions at the levels used.
Impacts
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Publications
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Progress 01/01/80 to 12/30/80
Outputs
The sukiyaki volatiles obtained from beef, heated with vegetables and seasonings(sugar and soy sauce) under simulated cooking conditions, were isolated and identified by gas-liquid chromatography/mass spectrometry. Sixty-three compounds were postitively identified. The included furans, ketones, aldehydes, esters, acids, alcohols, pyrazines, hydrocarbons, and pyrroles. Carcinogenic dimethylnitrosamine was identified at a level of (0.02 ppb) in the dichloromethane extract of the above sukiyaki broth using a thermal energy analyzer (TEA) combined with a gas chromatograph.
Impacts
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Publications
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