Phytochemicals are non-nutritive plant chemicals that have protective properties against diseases. Some phytochemicals have antioxidant properties which protect cells from free radicals—harmful unstable molecules that damage cells and contribute to aging and diseases including cancer.
Common antioxidants like ascorbic acid, carotenoids, and phenolic compounds are substances in fruits and vegetables which can help reduce the incidence of age-related degenerative diseases such as cancer, cardiovascular disease, cataracts, and brain and immune dysfunction (Ames, Shigenaga and Hagen, 1993; Liu, 2004; Scalbert and Williamson, 2000; Eastwood, 1999; Zino et al., 1997; Ness and Powles, 1997). However, results of clinical trials done to assess the efficacy of antioxidants including vitamin C, vitamin E, and â-carotene against free radicals are rather inconclusive (Wu et al., 2004; Halvorsen et al., 2002). Prof. Rowena Grace O. Rumbaoa and Ms. Djanna F. Cornago of the College of Home Economics conducted a study entitled Evaluation of Antioxidant Activities of Some Local Rootcrops (2006) to determine if phenolic compounds in these agricultural products have antioxidant activity. They used root crops that are commonly consumed as food in the Philippines.
In the study, the researchers screened the phenolic content of different varieties of root crops cultivated in the Philippines: purple yam or ubi (Dioscorea alata), lesser yam or tugui (Dioscorea esculenta), potato (Solanum tuberosum), sweet potato or kamote (Ipomoea batatas), cassava (Manihot esculenta), taro or gabi (Colocasia esculenta), carrot (Daucus carota) and yacon (Smallanthus sonchifolius). Through in vitro  evaluation of the root crop extracts, it was found out that root crops are rich sources of phenolic compounds. Analyzing the antioxidant properties of the root crop extracts also revealed significant antioxidant activity compared to á-tocopherol, or commonly known as vitamin E. The root crop with the highest antioxidant activity was sweet potato, followed by taro, potato and purple yam while the lowest antioxidant activity was obtained from carrot. Although carrot contains carotenoids, a known antioxidant, its mechanism of action is different from the assay used in their study.
This study provides baseline data for future clinical trials, commercial applications, and studies on production processes and food processing. For future applications of the results of this study, researchers Rumbaoa and Cornago recommend that genotype, growth conditions, sample preparation and extraction of root crops must be considered in determining the desirable amount of phenolic content and antioxidant property. Also, for applications to future clinical studies, results of the study must be supported with bioavailability  data and antioxidant activity in vivo .
Rowena Grace O. Rumbaoa is an assistant professor at the Department of Food Science and Nutrition, College of Home Economics in the University of the Philippines Diliman. She teaches Food Chemistry and Analysis, Food Packaging, Food Processing, and Principles of Food Preparation. She is currently involved in a research on the nutrient fortification of aseptically processed fruit and vegetable juice blends.
Djanna F. Cornago is also a faculty member at the Department of Food and Science and Nutrition in U.P. Diliman. She is currently handling courses on General Microbiology, Food Microbiology, and Food Hygiene and Sanitation. Her research interests include microbial and chemical food safety and postharvest handling of food.
 In vivo means in the living body of a plant or animal.
Researchers simplify tiny structures' construction drip by drip
12.11.2018 | Princeton University, Engineering School
Mandibular movement monitoring may help improve oral sleep apnea devices
06.11.2018 | Elsevier
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences