Progress 10/01/12 to 09/30/17
Outputs
Target Audience:Regional (Pacific islands), national, and international food scientists, pharmaceutical scientists, consumers for natural products, food processors, and entrepreneurs Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Research associates, college students, and/or high school students on Guam were trained in determining total phenolics, total flavonoids, antioxidant activity, antimicrobial activity, and mutagenicity and antimutagenicity of natural products. How have the results been disseminated to communities of interest?The results of the studies were presented in symposiums and seminars at the University of Guam, national conference, and Summer Scientific Research Symposiums in Bethesda, MD at the National Institutes of Health in Washington DC. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
To accomplish the goal, three research areas were studied from 10/01/2012 to 09/30/2017. First, we investigated the effect of hot-air dehydration on total phenolics, total flavonoids, and antioxidant activity of Hibicus flower (Hibiscus rosasinensis) and observed that the hot-air dehydration increased total phenolics, total flavonoids, and antioxidant activity in the extract of Hibicus flower petals compared with those dried by natural dehydration at room temperature. The result suggested the hot-air dehydration is an effective method to dry Hibicus flower for infusing herbal tea. Second, we studied the effect of lemongrass essential oil (LG EO) incorporated into beta-cyclodextrins (beta-CD) on antimicrobial activity against molds and yeast and mesophilic bacteria. We noted that the complex of LG EO with 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) exhibited antimicrobial activity against the growth molds on the fresh-cut papaya more effectively than the complex of lemongrass essential oils with beta-CD. The result suggested that the high solubility of HP-beta-CD may promote the release of LG EO vapor, which resulted in an effective anti-molds activity of LG EO/HP-beta-CD complex for fresh-cut papaya. We also observed the complex of LG EO/beta-CD slightly reduced the number of molds and yeasts on fresh papaya during the washing step for preparing fresh-cut papaya. Third, we determined antimutagenicity of tropical plant extracts using Ames Salmonella mutagenicity assay. The selected plants were soursop (Annona muricata) fruit and leaves, avocado (Persea Americano) seeds, and noni juice. We found that the extract of soursop fruit juice exhibited antimutagenicity against base-pair substitution mutation and the hot and cold extracts of avocado seeds exhibited antimutagenicity against frameshift mutations. However, the extract of soursop leaves showed a week mutagenic activity. The results suggested that some phytochemicals or components in tropical soursop fruit juice and avocado seeds may possess biological property of antimutagenicity for health benefit. Soursop leaves may have negative health effect (mutagenic activity) for consumers using soursop leaves as herbal tea.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Yang J. and Gadi. 2013. Total phenolics, flavonoids, and antioxidant activity of Hibicus rosasinensis tea as affected by dehydration. The 2013th IFT Annual meeting, Chicago, Illinois. Technical Program (Abstract): 311-52.
Yang, J., Afaisen, S.J., Gadi, R. 2016. Antimicrobial activity of noni fruit essential oil on Escherichia coli O157:H and Salmonella Enteritidis. Micronesica. 2016-05: 1-10
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Food scientists, pharmaceutical scientists, consumers for natural products Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A research associate and a high school student on Guam were trained in determining mutagenicity and antimutagenicity of natural products. The high school student was an intern in the summer program of the National Institute of Health/National Institute for Diabetes, Digestive & Kidney Short Term Education Program for Underrepresented Persons (NIH/NIDDK STEP-UP). How have the results been disseminated to communities of interest?The results of the study were presented in a Symposium at the University of Guam. The results were also presented at a Summer Scientific Research Symposium in Bethesda, MD at the National Institutes of Health in Washington DC. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
We determined the antimutagenicity of Avocado (Persea Americano) seed extracts and noni (Moninda citrifolia) fruit juice by the Ames Salmonella mutagenicity assay. The seeds of tropical avocado plant are reported to provide purported health benefits, such as anticancer activity, preventing cardiovascular disease, reducing inflammation, and rejuvenating skin. Noni is a tropical medicinal plant; the phytochemicals identified from its fruits and leaves exhibit biological properties of scavenging free radicals, antimutagenicity, anticarcinoma activity, and anti-inflammatory activity. The extracts of avocado seeds were prepared by extracting small pieces of the seeds with boiling water for 15 min or with water at 24 °C for 60 min under agitation. The fermented noni juice was collected by fermenting fruit at room temperature for 3 months; the fresh noni juice was obtained by freezing the fruit overnight and thawing the fruit at room temperature for more than 6 hours. The extracts of avocado seeds and noni juice were filtered with a 0.2 mm filter for sterilization and then freeze-dried into powder for the anti-mutagenicity assay. In the Ames test for antimutagenicity, the strains of Salmonella typhimurium TA 100 and TA98 were cultured in nutrient broth #2 and incubated overnight at 37 °C. The bacteria concentration of 1-2´108 (cells/ml) were used for the assay. With sterile condition, 100 ml of buffer or carcinogen (positive controls, 4-nitroquinoline N-oxide or sodium azide), 100 ml of extract in phosphate buffer, 100 ml of Salmonella culture were mixed. After incubation at 37 °C for 20 min, a 2 ml of molten top agar was added; the mixture was poured onto the surface of bottom agar in a petri dish. After incubation at 37 °C for 48 hours, the number of Salmonella revertant colonies was counted and calculated for the inhibition of mutagenicity (%). Compared with the positive control (4-nitroquinoline N-oxide), the cold and hot extract of avocado seeds at 10 mg/plate exhibited an inhibition value at 57 and 34%, indicating a strong and moderate antimutagenicity against Salmonella strain TA98, respectively. However, the fermented and fresh noni juice at 10 mg/plate did not exhibited antimutagenicity against Salmonella typhimurium TA98. With Salmonella strain TA100, the cold and hot extract of avocado seeds and the fermented and fresh noni juice at 10 mg/plate did not significantly decrease of revertant number compared to the number of the positive control (sodium azide), indicating that avocado seed extracts and noni juice did not show antimutagenicity against Salmonella strain TA100. The result suggested that avocado seeds possess some phytochemicals or components, which possess biological property against the frameshift mutation. There is a need to do further investigation of antimutagenicity of avocado seeds.
Publications
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One high school student were trained in summer. How have the results been disseminated to communities of interest?The reseach results were presented in a seminar at Universit of Guam. What do you plan to do during the next reporting period to accomplish the goals?We plan to investigate antimutagenicity and mutagenicity of other tropical plants and fruits.
Impacts
What was accomplished under these goals?
We studied antimutagenicity and mutagenicity of soursop (Annona muricata) fruit and leav using Ames Salmonellaassay. Soursop is aunique tropicalfruit with pleasantaroma and sousop leaves are consumed as tea for health benefits.Soursop fruit juice was extracted byafreezing-thawing method. The soursop leavesdehydrated at 45ºC for2 hourswere extracted with cold and hot waterfor 2 hours. The fruit juice extract and leave extracts were freeze-dried at -45ºC for 48 hours for antimutagenicity and mutagenicity assays. The Salmonellastrain TA100 andsodium azide as a mutagen or a positivecontrol were used in the Ames test. The concentration of fruit juice extract at0-100 ug/plate andleave extracts at 0-3333 ug/plate were used forantimutagenicity and mutagenicity, respectively. The soursop fruit juice exhibited a inhibition on the growth ofSalmonella revertants, indicating antimutagenecity activity.The antimuatagenic activity increased with an increase ofthe fruit extract concentration.The juice extract concentration at 50 ug/plate inhibitedSalmonellarevertants by 50%. Thecold and hot leave extracts exhibited an increase of Salmonella revertants by 1.4 times, showinga weak mutagenic activity.The results suggestedthat the soursop fruit may provide health benefit in the biological activity of antimutagenicity. However,the soursop leaves may have a health concern.Further confirmation ofantimutagenic and mutagenic activityof soursop fruit and leaves is needed.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Yang, J., Afaisen, S.J., Gadi, R. 2016. Antimicrobial activity of noni fruit essential oil on Escherichia coli O157:H7 and Salmonella Enteritidis. Micronesica. 2016-05: 110.
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A research associate and undergraduate student was trained to prepare beta-CD/LG EO complex, prepare fresh-cut papaya, and determine the total aerobic plate count and molds and yeast on papaya fruit. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?For the next reporting period, we plan to evaluate the safety of tropical plants, fruit, and vegetables for consumers by determining the mutagenicity of their extracts or fractions with Ames test.
Impacts
What was accomplished under these goals?
We determined the antimicrobial activity ofbeta-cyclodextrin (beta-CD)/essential oil (EO) complex against mesophilic bacteria and molds and yeast on papaya fruit. The fresh papaya fruit was washed for 5 min with water (control), water containing the complex (2.2%) of beta-CD/lemongrass (LG) EO (ratio: 10/1), and household bleach solution (chlorine at 1000 ppm). After washing, the aerobic plate count and molds and yeasts on the surface of papaya fruit as well as the prepared fresh-cut papaya were determined. Comparing the washing withwater (control), the washing with beta-CD/LG complex reduced 1.0 log CFU/mg of molds and yeasts on papaya surface while the washing with household bleach solution reduced 1.7 log CFU/mg. The washing with beta-CD/LG EO complex did not exhibited a significant reduction of total aerobic plate count compared with the washing with water. However, the washing with household bleach solutionreduced 1.3 log CFU/mg of total aerobic plate count compared to the washing with water. After washing treatment and preparing fresh-cut papaya, fresh-cut papaya did not exhibit a significant difference in the total aerobic plate count and molds and yeastsamong the washing with water, beta-CD/LG EO complex solution, and household bleach solution. After storage at 4 C for 4 and 11 days, no significant difference in total aerobic plate count and molds and yeastswas observed among the three washing treatments. This study suggested that the lemongrass EO/b-CD complex may be useful to decrease molds and yeasts contamination of fresh papaya fruit and extend the fruit shelf-life. The washing treatment concentration and time with beta-CD/LG EO complex for papaya needs further study.
Publications
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Food processors, entrepreneurs, farmers, food technologists, and food scientists. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? To confirm and determine the effectiveness of various essential oils/HP-ß-CD and ß-CD complex against the growth ofmoldson different tropical fruits.
Impacts
What was accomplished under these goals?
Essential oils in vapor phase exhibits antimicrobial activitygreater than essential oil in liquid phase. Controlling the release of essential oil vapor may have potential applications in inhibiting the growth of microorganisms on fresh fruits and vegetables. ß-Cyclodextrin (ß-CD) is a cyclic oligosaccharide with a structure hydrophobic inside and hydrophilic outside. Essential oil (EO) can be incorporated into ß-CD to form a complex. The complex of EO/ß-CD can release the EO vapor gradually in a closed system when ß-CD is solubilized by an increasein the partial vapor pressure of water from the respiration of fresh fruits. To determine the effect of lemongrass (LG) EO/ß-CD complex on the mold growth of tropical fruits, we used a dry-mixing method to incorporate LG EO into ß-CD and 2-hydroxypropyl-beta-CD (HP-ß-CD) to form the complex. We put the LG EO/ß-CD complex in tea bags and attached the tea bags in the clam-shell food boxes, which contained fresh-cut papaya. We stored the fresh-cut papaya at room temperature for 5 days for observation. We observed that the molds did not grow on the fresh-cut papaya in the boxes attached with LG EO/HP-ß-CD complex. However, molds grew on the fresh-cut papaya (controls) without LG EO/ß-CD complex and fresh-cut papaya with LG EO/ß-CD complex. The results showed that the LG EO vapor released from HP-ß-CD inhibited the growth of molds on fresh-cut papaya. Compared with ß-CD, the solubility of HP-ß-CD may promote the release of LG EO vapor from the HP-ß-CD complex more efficiently than the ß-CD complex, resulting in an effective anti-molds activityofLG EO/HP-ß-CD on fresh-cut papaya.
Publications
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Progress 10/01/12 to 09/30/13
Outputs
Target Audience: Farmers,consumers, college students, extension educators Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Research assistant, Catherine Nguyen,and undergraduate students at University of Guam, anda high school student in the community of Guamwere involved in theactivities of this project and have been trained in conducting research experiments and preparing Hibiscus tea. How have the results been disseminated to communities of interest? The information about the health benefits of Hibiscus teawas shared in theclassrelated to food science and technology.The information about preparing Hibiscus tea was shared in a colloge seminar. What do you plan to do during the next reporting period to accomplish the goals? We plan to conduct some research experiments related to health benefits or toxicities of some other tropical plants, fruits, and vegetables.
Impacts
What was accomplished under these goals?
We studied the effect of dehydration on anthocyanin content of Hibiscus rosasinensisflower. Hibiscus rosasinensis L. is an ornamental plant grown in tropical and subtropical regions of the world. The extracts of the plant flowers exhibited antidiabetic, antihypertensive, antioestrogenic, and anticonvulsant properties. The flowers of H. rosasinensis are edible and naturally dehydrated for infusing herbal tea. Hibiscustea provides health benefits to people.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Yang J. and Gadi R. 2013. Total phenolics, flavonoids, and antioxidant activity of Hibiscus rosasinensis tea as affected by dehydration. The 2013th Annual IFT Annual Meeting. Chicago, Illinois. Technical Program: 311-52.
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