Progress 10/01/03 to 09/30/07
Outputs
OUTPUTS: Functional ingredients were extracted from the by-products of two major NC crops, namely peanuts and sweet potatoes. Such ingredients were characterized and tested for potential use as bioactive compounds and/or functional ingredients in foods. For peanut, water and ethanol extracts of peanut skin showed total antioxidant activities (TAA) of 3.59 and 1.91 (mM Trolox/mM phenolics), respectively, versus 2.46 for green tea extract. Three classes of phenolics were found in peanut skin extracts (PSE): phenolic acids, flavonoids, and stilbene. LC-MS analysis revealed that the total catechins, procyanidin dimers, trimers, and tetramers in directly peeled PSE were 16.1, 111.29, 221.33, and 296.07 mg/100g, respectively, versus 8.79, 143.48, 157.53, and 203.91 mg/100 g, respectively, in roasted dry skin. Overall, TAAs and free radical scavenging capacities of PSE were all higher than those of Trolox and Vitamin C at equivalent concentration, indicating that peanut skin contains potent
phenolic antioxidants. The latter were evaluated for their potentials as inhibitors of lipid oxidation in cooked meat and as antimicrobial agents in raw meat. Results indicate that cooked ground beef containing PSE exhibited significantly lower peroxide and TABRS values during cooking and storage. Samples with 0.06% and higher PSE showed similar peroxide and TBARS values to those of samples containing 0.02% commercial BHT. The use of crude PSE as antimicrobial preservative in raw ground beef resulted in 50% inhibition of total aerobic bacterial growth in samples containing 0.1% PSE. At 1.0% PSE, the bacterial inhibition rate reached 85-99%. Meat samples containing PSE retained more of the fresh red color compared to their negative control. Significant inhibition of pathogens was also observed at 0.2% PSE and higher. Peanut skin, a by-product of the peanut processing industry, was found to contain potent bioactive antioxidants that showed strong antioxidant and antimicrobial activity
in cooked and raw ground beef, respectively. Peanut protein concentrates (PPC) were isolated from defatted peanut flour, an underutilized by-product of peanut oil extraction. PPC contained over 85% protein with minimum solubility at pH 4 and maximum solubility above pH 9. Spray dried PPCs exhibited better emulsifying and foaming capacity than vacuum oven dried PPC. Spray dried PPCs also showed comparable oil binding and foaming capacity to commercial soy protein isolate. These data suggest that value-added PPC would be suitable for food formulations requiring high emulsifying capacity. TAA in water soluble fractions recovered from the peel and flesh of three NC SP varieties ranged from 33 to 70%. TAAs of water-soluble antioxidants were highly correlated (R2=0.99) with the total phenolic and β-carotene contents. Similar trends were observed for the lipophilic extracts which showed higher antioxidant activity (up to 90%), mainly due to carotenes and tocopherols. Overall, SP peels
exhibited the highest antioxidant activity suggesting that they contain high levels of bioactive compounds that can be used in functional food industry formulations, thereby adding value to the SP industry.
PARTICIPANTS: Faculty Investigators--Dr. Mohamed Ahmedna, African male, served as project PI and Dr. Tracy Hanner, African American Male, served as project CoPI. Graduate students: Mr. Brian Green, an African American male, MS. in Food Sciences, and Mr Porter Myrick, an African American Male, BS/MS. degrees in Food Sciences, Ms Dacia Whitsett, African American Female, BS/MS degrees in Food Sciences. Research associates: Dr. Jianmei Yu, an Asian female.
TARGET AUDIENCES: Students in Agricultural and Food Sciences Scientific community Rural residents Interested private sector
Impacts
This project had a direct positive impact on investigators, students, and the institution and potential benefits for agriculture and food systems. The project enabled the PI to build capacity and develop human resources in the School of Agriculture and Environmental Sciences through hiring students and research associates, purchasing necessary equipment and supplies, participating in professional meetings, and publications. The PI (Mohamed Ahmedna) was the recipient of the 2005 USAID George Washington Carver Agricultural Excellence award and the 2007 NC A&T Outstanding Senior Researcher award. In addition to the PIs, the project provided 4 students with unique experiential learning and research experiences in food and agricultural sciences while working toward their graduate degrees in Food and Nutritional Sciences. It also provided participating students multiple professional growth opportunities through paid travel to attend national and local meetings where they
expanded their horizon and network. The project also enabled the research Associate (Dr. Jianmei Yu), a young scientist, to engage in research, publish and earn professional recognitions such as the 2006 NCA&T Gamma Sigma Delta Chapter award of Excellence in Research. At the institutional level, the project enabled the Department of Family and Consumer Sciences to purchase several pieces of equipment and leverage project resources to acquire three expensive pieces of equipment from other funding sources. Overall, the PIs benefited from leveraging the capacity building funds to secure over $1.5 million of funding for related research ideas. The cumulative effect of these outputs resulted in enhanced institutional capacity building, as intended by the USDA, and higher national visibility of the university through presentations by PIs and students at numerous professional meetings. In addition to the institutional capacity building impact (human and infrastructure), research findings
from this project have the potential to positively impact the rural economy, the environment, and public health through production of health promoting compounds and inexpensive food preservatives from underutilized agricultural by-products such as peanut skins. Such value-added bioactive compounds have the potential to promote public health and add value to the agricultural sector. Efforts are in progress to license project outcomes to interested industry partners. In addition, project findings were widely disseminated through numerous peer-reviewed publications and presentations and media coverage thereby enhancing the visibility and standing of the university. To further highlight project, the PI also organized and chaired symposium entitled "Status and Prospects of Value Added Nutraceuticals from Underutilized Food Industry By-products", hosted by the Division of Nutraceutical and Functional Foods, Institute of Food Technologists (IFT) at the 2005 Annual Meeting and Food Expo of
IFT, New Orleans, LA, July 16-21, 2005.
Publications
- Goktepe, I. , Juneja, V.K., Ahmedna, M. (Eds.) 2005. PROBIOTICS IN FOOD SAFETY AND HUMAN HEALTH CRC Press, Boca Raton, FL.
- Yu, J., Ahmedna, M. and Goktepe, I. 2006. Peanut Skin Phenolics: Extraction, Identification, Antioxidant Activity and Potential Applications. Chapter 16 In F. Shahidi and Chi-Tang Ho (Editors) ANTIOXIDANTS: MEASUREMENT AND APPLICATIONS, ACS Symposium Series # 956. Pages 226-241.
- Rehrah, Dj., Ahmedna, M., Yu, J., Goktepe, I., Hurley, S., Hanner, T. and Rao-Patel, A. 2007. Enhanced Cholesterol and Triglyceride Lowering Effect of West African Green Tea. J. Science of Food and Agriculture, 87 (2007): 1323-1329.
- Yu, J., Ahmedna, M, Goktepe, I and Dai, J., 2006. Peanut Skin Procyanidins: Composition and Antioxidant Activity as Affected by Processing: J. Food Comp. and Analysis 19 (2006) 364-371
- Yu, J., Ahmedna, M., and Goktepe, I. A., 2005. Effects of processing methods and extraction solvents on concentration and antioxidanats activity of peanut skin phenolics. Food Chemistry, Vol 90/1-2 pp 199-206.
- Yu, J., Ahmedna, M., Myrick, P., Goktepe, I. 2007. Antioxidant and antimicrobial effects of peanut skin extract in selected food models. Abstract # 095-27 book of abstracts, 2007 Annual Meeting of the Institute of Food Technologists, Chicago, IL, July 28-August 2, 2007.
- Yu, J. P. Myric, M. Ahmedna and I. Goktepe. Antioxidative and antibacterial effects of peanut skin extract in select food models. Paper# 066190. 2006 ASABE Annual International Meeting. July 9-13, 2006. Portland, Oregon.
- Yu, J., Ahmedna, M., and Goktepe, I. 2006. Peanut skin antioxidants: separation, identification, and quantification as affected by processing methods. The 14th Biennial ARD Research Symposium, Atlanta, GA, April 1-5, 2006.
- Ahmedna, M., Yu, J., and Goktepe, I. 2005. Characterization and activity of peanut skin antioxidants. PacificChem 2005, Honolulu, Hawaii, December 15-21, 2005.
- Ahmedna, M., Yu, J., and Goktepe, I. 2005. Peanut Skin Procyanidins: Composition and Antioxidant Activity as Affected by Processing. IFT Symposium # 65, paper #1, 2005 Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 15-19.
- Ahmedna, M., Yu, J., and Goktepe, I., 2005. Value-added nutraceuticals from peanut processing by-products. Paper # 31, 2005 Annual meeting of the American Peanut Research and Education Society, Portsmouth, VA, July 12-15, 2005.
- Yu, J., Myrick, P., Ahmedna, M., Rehrah,D.. and Goktepe, I. 2005. Functional properties of peanut protein concentrates from defatted peanut flour. Paper #71B-18, The 2005 Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 15-19, 2005.
- Yu, J., Rehrah, D., Ahmedna, M., and Goktepe, I., 2005. Functional properties and potential applications of peanut protein isolate/concentrate. Paper #120, 2005 Annual meeting of the American Peanut Research and Education Society, Portsmouth, VA, July 12-15, 2005.
- Yu, J., Myrick, P., Ahmedna, M., Rehrah,D. and Goktepe, I. 2005. Functional properties of peanut protein concentrates from defatted peanut flour. The 2005 Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 15-19, 2005.
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Progress 01/01/06 to 12/31/06
Outputs
The potential of peanut skin polyphenols as inhibitor of lipid oxidation in cooked meat and as antimicrobial agent in raw chicken meat was evaluated. Ground beef was mixed with peanut skin extract (PSE) at levels of 0, 0.02, 0.04, 0.06, 0.08 and 0.1% using a food processor. 0.02% BHT was used as a positive control. The meat was then cooked and stored at 4 degrees C for 0, 1, 2, 3 or 4 weeks. Samples were taken weekly for peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) determination. To evaluate antimicrobial activity of PSE, cubes of chicken breast were dipped in water solutions containing 0, 200, 400, 600, 800 and 1000 ppm peanut skin polyphenols for 1 min, packed in Ziploc bags and stored at 4 degrees C. Chicken samples were taken every 3 days, and aerobic and anaerobic bacteria were determined by a standard plate count method. Results indicate that both PV and TABRS of samples containing PSE increased slower than that without PSE during
storage. Samples with 0.06% and higher PSE showed PV and TBARS values comparable to those of samples containing 0.02% BHT. Therefore, PSE may be a promising natural antioxidant to inhibit lipid oxidation in cooked meat. However, PSE did not show significant antimicrobial effect in raw chicken breast at the concentration range used in this study. In a second study, peanut protein concentrate (PPC) was isolated from fermented and unfermented defatted peanut flour by isoelectric precipitation and physical separation procedures. PPC was dried by spray or vacuum drying. PPC powders from each drying technique were evaluated for proximate composition and functional properties (protein solubility, water/oil binding capacity, emulsifying capacity, foaming capacity and viscosity) along with defatted peanut flour and soy protein isolate as references. PPC contained over 85% protein and exhibited a solubility profile similar to that of peanut flour, with minimum solubility observed at pH 3.5 -
4.5 and maximum solubility at pH 10 and higher. Roasting reduced all functional properties of defatted peanut flour, while fermentation had the reverse effect. Spray dried PPCs exhibited better functional properties − particularly emulsifying capacity and foaming capacity − than vacuum oven dried PPC. Spray dried PPCs also showed oil binding and foaming capacity comparable to commercially available soy protein isolate (SPC). At equivalent concentrations and room temperature, PPC suspension exhibited lower viscosity than soy protein isolate (SPI) suspensions. However, upon heating to 90 degrees C for 30 minutes, the viscosity of PPC suspension increased sharply. These results suggest that PPC could be used in food formulations requiring high emulsifying capacity, but would not be suitable for applications requiring high water retention and foaming capacity.
Impacts
Peanut production contributes over $4 billion to the U.S. economy each year. Most peanuts grown in the United States are used for oil production, peanut butter, confections, and snack products which account for an even larger market segment. Peanut processing yields various underutilized byproducts such as peanut skins and defatted peanut flour, and peanut processors are seeking ways to add value to the industry through new and expanded utilization of peanut processing byproducts. The present study showed that the natural antioxidants in peanut skin extracts can be used to prevent lipid oxidation in food products (e.g. cooked meats) to a degree that rivals BHT, a commercial chemical antioxidant widely used as a food preservative. Thus, peanut skins have the potential to provide an inexpensive source of potent antioxidants for use as value-added functional ingredients and food preservatives. Research data also demonstrated that a peanut protein concentrate/isolate with
enhanced functional properties can be developed from defatted peanut flour. Such a value-added PPC could be a good source of protein fortification for a variety of food products for protein deficient consumers in developing countries as well as a functional ingredient for the peanut industry. These novel uses of peanut industry byproducts would add value to the peanut industry and enhance its profitability.
Publications
- Jianmei Yu, Mohamed Ahmedna, Ipek Goktepe, 2006. Peanut Protein Concentrate: Production and Functional Properties as Affected by Processing. Food Chemistry (in Press; available online since October 2006)
- Rehrah, D., Ahmedna, M., Yu, J, and Goktepe, I. 2006. Antioxidant activity of major sweet potato varieties. The 2006 Annual Meeting of the Institute of Food Technologists, Orlando, FL, June 24-28, 2006.
- Rehrah, D., Ahmedna, M., Yu, J, and Goktepe, I. 2006. Characterization of antioxidants in major sweet potato cultivars grown in North Carolina. The 14th Biennial ARD Research Symposium, Atlanta, GA, April 1-5, 2006.
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Progress 01/01/05 to 12/31/05
Outputs
Peels and flesh of three NC sweet potato cultivars (Beauregard, Hernandez, and Jewel) were freeze-dried and extracted with the mixture of acetone and hexane. Water and lipid soluble components in extracts were separated by phase separation. Antioxidant activity was measured using DPPH and peroxidation of linoleic acid for water soluble and lipid soluble compounds, respectively. Total phenolics were measured using the Folin-Ciocalteau method, while total carotenoinds and tocopherols were determined spectrophotometrically. TAA in a water soluble fraction for sweet potato peels and flesh ranged from 33 to 70%, depending on the variety, with the Hernandez variety exhibiting twice as much TAA as the other cultivars. Overall, the TAA of peels was significantly higher than that of the flesh. Regardless of variety, the hydrophilic antioxidant activities were highly correlated (R2=0.99) with the total phenolic and beta-carotene contents for both skin and flesh. Similar data
were observed for the lipophilic fraction which showed enhanced antioxidant activity (up to 90%). The latter was mainly due to carotenes and tocopherols as indicated by correlation coefficients near 1. In contrast to the water soluble fractions, lipophilic fractions from the Beauregard variety exhibited the highest antioxidant activity while Hernadez variety showed the least antioxidant activity, indicating a difference in composition. Overall, peels had the highest antioxidant activity for both water soluble and fat soluble fractions. This study showed that sweet potato peels contained high levels of nutraceuticals that can be used as inexpensive ingredients by the functional food industry. Such new uses have the potential to add value to the sweet potato industry.
Impacts
The development and characterization of naturally occurring functional (bioactive) compounds from agricultural sources such as peanut and sweet potato could help in the national effort to reduce the incidence of diet-related chronic diseases, while also adding value to the agricultural sector in the United States. This is especially true since the global functional foods market is estimated to be $48 billion per year, with the U.S. leading the world with $18.25 billion in annual sales. Furthermore, agricultural and food processing by-products offer plentiful and inexpensive sources of bioactive compounds for the growing needs of the functional food market. In fact, many of the highly nutritional compounds are often in by-product residues such as cereal bran, fruit and vegetable skins and peels. Thus, their health benefits are often overlooked.. Producers could benefit through new value-added utilization of by-products from their agricultural commodities. Consumers
could benefit from low cost health promoting compounds and foods from natural and renewable sources Diet-related chronic diseases (e.g., cardiovascular diseases, certain cancers, and osteoporosis) are major causes of preventable morbidity and mortality in the United States. According to the National Institutes of Health, just obesity-related diseases cost the US over $130 billion in health care and loss of productivity. The cost of diabetes tops the list with $63 billion, followed by heart diseases ($40.4 billion), osteoarthritis ($17.2 billion), cancer ($6.3 billion), and hypertension ($3.23 billion).
Publications
- Yu, J., M.,Ahmedna, and I., Goktepe, 2006.Peanut Skin Antioxidants: Separation, Identification, and Quantification as Affected by Processing Methods, 2006 ARD Meeting, Atlanta, GA.
- Yu, J., Ahmedna, M, Goktepe, I and Dai, J., 2005. Peanut Skin Procyanidins: Composition and Antioxidant Activity as Affected by Processing: J. Food Comp. and Analysis (In Press)
- Ahmedna, M., Yu, J., and Goktepe, I., 2005. Value-added nutraceuticals from peanut processing by-products. Paper # 31, 2005 Annual meeting of the American Peanut Research and Education Society, Portsmouth, VA, July 12-15, 2005.
- Ahmedna, M., Yu, J., and Goktepe, I. 2005. Peanut Skin Procyanidins: Composition and Antioxidant Activity as Affected by Processing. IFT Symposium # 65, paper #1, 2005 Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 15-19.
- Ahmedna, M., Yu, J., and Goktepe, I. 2005. Characterization and activity of peanut skin antioxidants. Pacific Chem 2005, Honolulu, Hawaii, December 15-21, 2005.
- Rehrah, Dj., M. Ahmedna, J. Yu, and I. Goktepe, 2006. Characterization of Antioxidants in Major Sweet Potato Cultivars Grown in NC. 2006 ARD Meeting, Atlanta, GA.
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Progress 01/01/04 to 12/30/04
Outputs
Three peanut processing methods (direct peeling, blanching, and roasting) were used to remove peanut skin. The composition of crude ethanol and water extracts of peanut skin removed by each method was determined by HPLC. Total phenolics (TP) and total antioxidant activity (TAA) of peanut skin extracts were determined and compared to those of green tea extracts under identical extraction and analytical conditions. To identify specific compounds, Catechins, A-type and B-type procyanidin dimers, trimers and tetramers in chemically purified peanut skin extracts were analyzed by LC-MS. Results show that one gram of peanut skin contained 90-125 mg TP. TAAs of water and ethanol extracts of peanut skin and green tea were 3.39 and 3.59, 1.91 and 2.46 (mM Trolox/mM phenolics), respectively. The skin processing method affected the total extractable phenolics. Skin removal by roasting yielded the highest concentration of TP, while blanching had lowest TP recovery. Three classes
of phenolics were found in peanut skin extracts, including phenolic acids (caffeic acid, chlorogenic acid, ferulic acid and coumaric acid), flavonoids (catechins and procyanidins) and stilbene (resveratrol). These compounds are potent antioxidants, particularly flavonoids and resveratrol, because of their inhibition of human LDL oxidation and prevention of DNA damage caused by oxidative stress. Specific LC-MS analysis revealed that the total catechins, procyanidin dimers, trimers and tetramers in directly peeled peanut skin were 16.1, 111.29, 221.33 and 296.07 mg/100g, respectively versus 8.79, 143.48, 157.53 and 203.91 mg/100 g, respectively in roasted dry skin. Overall, TAAs and free radical scavenging capacities of peanut skin extracts were all higher than those of Trolox and Vitamin C at equivalent concentration indicating that peanut skin contains potent antioxidants. Peanut skin, a by-product of the peanut processing industry, was found to contain potent antioxidants and could
provide an inexpensive source of antioxidants for use as functional ingredients or dietary supplements.
Impacts
Diet-related chronic diseases, including cardiovascular disease, certain cancers, and osteoporosis, are major causes of preventable morbidity and mortality in the US. According to the NIH, obesity-related diseases alone cost the U.S. more than $130 billion in health care and lost productivity. The cost of diabetes tops the list at $63 billion, followed by heart diseases ($40.4 billion), osteoarthritis ($17.2 billion), cancer ($6.3 billion), and hypertension ($3.23 billion). Add to this list other diet related chronic diseases unrelated to obesity, and the economic losses increase dramatically The development and characterization of naturally occurring and safe functional (bioactive) compounds from agricultural sources will not only help in the national effort to reduce the incidence of diet related chronic diseases, but also add value to the U.S. agricultural sector. This is especially true in light of the fact that the global functional food market is estimated to be
$48 billion/year, and the US leads the world with annual sales of $18.25 billion. Many of the highly nutritional compounds are often found in by-product residues such as cereal bran, fruit and vegetable skins/peels. Thus, their health benefits are often overlooked. Therefore, novel value-added uses for these by-products will benefit consumers by providing low cost health promoting compound/foods from natural and renewable sources. Producers will benefit as well, through new, value-added utilization of by-products from their agricultural commodities.
Publications
- Jianmei Yu, Mohamed Ahmedna, Ipek Goktepe and Jian Dai 2005. Peanut Skin Procyanidins: composition and antioxidant activities as affected by processing. J. Food Composition and Analysis (Submitted).
- Yu, J., Ahmedna, M., Goktepe, I., and Proctor, A., 2004. Effects of processing methods and extraction solvents on concentration and antioxidanats activity of peanut skin phenolics. Food Chemistry, Vol 90/1-2 pp 199-206.
- J. Yu, M. Ahmedna, and A. Proctor, 2004. Antioxidants in peanut skin: Identification and quantification . Paper # 67B-27, 2004 Annual Meeting of the Institute of Food Technologists, Las Vegas, Nevada, July 12-16, 2004.
- Patents/Invention disclosures: M. Ahmedna and J. Yu 2004. Invention disclosure entitled 'Process for recovery and use of polyphenols and other health promoting compounds from peanut skin' filed December 8, 2004.
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Progress 01/01/03 to 12/31/03
Outputs
Research work will be carried out to meet the following objectives: (1) Determine the overall activity and quantify the target compounds in peanut shells and sweet potato peels with emphasis on value-added utilization, (2) Test biological activity of active compounds using biochemical assays, (3) Test potential health benefits of the most promising active compounds in rat animal models to demonstrate potential use as human health promoters, and (4) Explore the development of new functional foods incorporating the most promising functional ingredients.
Impacts
Diet-related chronic diseases, including cardiovascular disease, certain cancers, and osteoporosis, are major causes of preventable morbidity and mortality in the US. According to the NIH, obesity-related diseases alone cost the U.S. more than $130 billion in health care and lost productivity. The cost of diabetes tops the list at $63 billion, followed by heart diseases ($40.4 billion), osteoarthritis ($17.2 billion), cancer ($6.3 billion), and hypertension ($3.23 billion). Add to this list other diet related chronic diseases unrelated to obesity, and the economic losses increase dramatically The development and characterization of naturally occurring and safe functional (bioactive) compounds from agricultural sources will not only help in the national effort to reduce the incidence of diet related chronic diseases, but also add value to the U.S. agricultural sector. This is especially true in light of the fact that the global functional food market is estimated to be
$48 billion/year, and the US leads the world with annual sales of $18.25 billion. Many of the highly nutritional compounds are often found in by-product residues such as cereal bran, fruit and vegetable skins/peels. Thus, their health benefits are often overlooked. Therefore, novel value-added uses for these by-products will benefit consumers by providing low cost health promoting compound/foods from natural and renewable sources. Producers will benefit as well, through new, value-added utilization of by-products from their agricultural commodities.
Publications
- No publications reported this period
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