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.
New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg
Disarray in the brain
18.12.2017 | Universität zu Lübeck
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
22.01.2018 | Materials Sciences
22.01.2018 | Earth Sciences
22.01.2018 | Life Sciences