Reena Randhir

Bio: Reena Randhir is an academic researcher from University of Massachusetts Amherst. The author has contributed to research in topics: Antioxidant & Superoxide dismutase. The author has an hindex of 16, co-authored 23 publications receiving 1392 citations. Previous affiliations of Reena Randhir include Purdue University & Springfield Technical Community College.

Phenolics, their antioxidant and antimicrobial activity in dark germinated fenugreek sprouts in response to peptide and phytochemical elicitors.

Abstract: The phenylpropanoid pathway (PPP) was stimulated in fenugreek sprouts through the pentose phosphate and shikimate pathway, by natural elicitors such as Fish Protein Hydrolysates (FPH), Lactoferrin (LF) and Oregano Extract (OE). Among treatments 0.5 ml/L FPH elicited fenugreek sprouts had the highest phenolic content of 0.75 mg/g FW on day 3 of germination which was approximately 25 % higher than control on the same day. The antioxidant activity estimated by beta-carotene assay was highest for LF and OE elicited sprouts on day 2 and 4, respectively with an antioxidant protection factor (APF) of 1.47 for both. In all treatments and control, higher antioxidant activity was observed during early germination, which correlates to higher phenolic content, suggesting that initially phenolics are antioxidant in nature. This increased activity also correlates with high guaiacol peroxidase (GPX) activity indicating that the polymerized phenolics required for lignification with growth have antioxidant function. The antioxidant activity as estimated by beta-carotene and 1,1,-diphenyl-2-picryl hydrazyl (DPPH) assays indicate that fenugreek sprout extract can quench the superoxide free radical and also possibly scavenge the hydrogen peroxide generated in the reaction mix. OE elicited the highest levo dihydroxy phenylalanine (L-DOPA) synthesis of 1.59 mg/g FW, followed by FPH with 1.56 mg/g FW and LF 1.5 mg/g FW all on day 2 which was 24.5%, 23 % and 20 % higher than control, respectively. Higher L-DOPA content was observed in the elicited fenugreek sprouts during early germination, correlating to high phenolics and antioxidant activity, suggesting that L-DOPA also contributes to the high antioxidant activity. The glucose-6-phosphate dehydrogenase (G6PDH) activity was higher during early germination (day 1-4) and gradually decreased during later stages (day 5-8) for all treatments and control. The early increase is possibly due to the carbohydrate mobilization from the cotyledons directed towards the high nutrient requirements of the growing sprout. As mobilization occurred, an allosteric feedback inhibition by sugar-phosphates is suggested, as lower G6PDH activity was observed on days 6-8. The elevated levels of GPX during early germination coincide with the higher phenolic synthesis; SOD activity and antioxidant activity suggests the elevated production and quenching of reactive oxygen species by elicitation. High antimicrobial activity against peptic ulcer-linked Helicobacter pylori was observed in the fenugreek sprout extract from control and LF treatments only. We hypothesized that in fenugreek sprouts, simple free phenolics that are less polymerized have more antimicrobial function.

Effect of thermal processing on phenolics, antioxidant activity and health-relevant functionality of select grain sprouts and seedlings

Abstract: The effect of thermal processing via autoclaving on modifications of total phenolics, antioxidant activity and functionality of wheat, buckwheat, corn and oats sprouts and seedlings were investigated. Functionality for type 2 diabetes related α-amylase, α-glucosidase inhibition and levo-dihydroxy phenylalanine ( l -DOPA) content, hypertension related angiotensin converting enzyme 1 (ACE) inhibition and ulcer related Helicobacter pylori inhibition were evaluated using in vitro assays. Thermal processing in general resulted in tissue browning leading to higher total phenolic content and free radical scavenging-linked antioxidant activity. It increased α-amylase inhibitory activity in buckwheat and oats but decreased in wheat and corn sprouts and seedlings. It increased α-glucosidase inhibitory activity in wheat, buckwheat and oats but decreased in corn sprouts. It reduced the cognitive function/diabetes related l -DOPA content in all grains sprouts and seedlings tested. It increased ACE inhibitory activity in buckwheat and oats, but decreased in wheat and corn sprouts. It also improved the ulcer related H. pylori inhibitory activity in all grain sprouts and seedlings studied. These changes in functionality are suggested to be due to modifications in the total phenolic content and profile by phenolic oxidation or polymerization caused by thermal processing. Therefore, diet designs for chronic disease management will have to consider thermal processing-linked modification of bioactive ingredient profiles. Industrial relevance Thermal processing altered the total phenolic content and antioxidant activity in winter wheat, buckwheat, corn and oats sprouts and seedlings. It modified the α-amylase inhibitory activity, α-glucosidase inhibitory activity, l -DOPA content, ACE inhibitory activity and H. pylori inhibitory activity of samples. Therefore, the food processing industry and diet design for chronic disease management will have to consider thermal processing-linked modification of bioactive ingredient profiles for more effective health benefits.

Mung beans processed by solid-state bioconversion improves phenolic content and functionality relevant for diabetes and ulcer management

Abstract: Mung bean substrate was enriched with phenolic antioxidants and levo-dihydroxy phenylalanine ( l -DOPA) through solid-state bioconversion (SSB) by Rhizopus oligosporus, with the goal to enhance health-linked functionality. The alpha-amylase inhibition linked to diabetes management and Helicobacter pylori inhibition linked to peptic ulcer management were investigated in bioprocessed extracts. The protein content and β-glucosidase activity of the substrate which are indicators of effective fungal colonization, increased with growth. The phenolic content increase with growth was linked to fungal β-glucosidase activity, indicating phenolic mobilization. The antioxidant activity as measured by DPPH (1,1-diphenyl-2-picrylhydrazyl) inhibition method were high (65%) initially and increased to 90% on day 12, than maintained higher levels during the rest of growth. The antioxidant activity measured by β-carotene assay was high between days 4–8 when phenolic levels increased. Fungal-linked superoxide dismutase (SOD) activity was high in late stages indicating quenching of reactive oxygen species. The l -DOPA content was low during early growth stage (0.6–0.7 mg/g DW) and gradually doubled to 1.2 mg/g DW in late stages. The α-amylase inhibition potential was moderately high during early stages (days 0–2) followed by higher inhibition during days 4–10 which correlate to higher phenolic content. The change in the antimicrobial activities of the extracts against H. pylori was high on day 4 and was associated with high antioxidant activity but not high phenolic content. Elevated inhibition on day 8 directly correlated with high total phenolics content suggesting the role of phenolic mobilization. The major implication from this research is that SSB is a good strategy to improve the phenolic content of mung beans for enhanced functionality with improved antioxidant activity that contributes to α-amylase inhibition relevant to potential diabetes management and H. pylori inhibition linked to peptic ulcer management. Industrial relevance Solid State Bioconversion (SSB) of mung bean by R. oligosporus is a good strategy to enhance ingredient functionality due to mobilization of phenolic antioxidants. Such enhanced phenolic antioxidant activity potentially contributes to health-relevant functionality such as amylase inhibition for diabetes management and H. pylori inhibition for peptic ulcer management. Optimization of such SSB systems at industrial scale can help large-scale low cost production of such health-relevant ingredients.

Millet Grains: Nutritional Quality, Processing, and Potential Health Benefits

Abstract: In the 21st century, climate changes, water scarcity, increasing world population, rising food prices, and other socioeconomic impacts are expected to generate a great threat to agriculture and food security worldwide, especially for the poorest people who live in arid and subarid regions. These impacts present a challenge to scientists and nutritionists to investigate the possibilities of producing, processing, and utilizing other potential food sources to end hunger and poverty. Cereal grains are the most important source of the world's food and have a significant role in the human diet throughout the world. As one of the most important drought-resistant crops, millet is widely grown in the semiarid tropics of Africa and Asia and constitutes a major source of carbohydrates and proteins for people living in these areas. In addition, because of their important contribution to national food security and potential health benefits, millet grain is now receiving increasing interest from food scientists, technologists, and nutritionists. The aim of this work was to review the recent advances in research carried out to date for purposes of evaluation of nutritional quality and potential health benefits of millet grains. Processing technologies used for improving the edible and nutritional characteristics of millet as well as challenges, limitations, and future perspectives to promote millet utilization as food for a large and growing population are also discussed.

An Overview of Plant Phenolic Compounds and Their Importance in Human Nutrition and Management of Type 2 Diabetes

Abstract: In this paper, the biosynthesis process of phenolic compounds in plants is summarized, which includes the shikimate, pentose phosphate and phenylpropanoid pathways. Plant phenolic compounds can act as antioxidants, structural polymers (lignin), attractants (flavonoids and carotenoids), UV screens (flavonoids), signal compounds (salicylic acid and flavonoids) and defense response chemicals (tannins and phytoalexins). From a human physiological standpoint, phenolic compounds are vital in defense responses, such as anti-aging, anti-inflammatory, antioxidant and anti-proliferative activities. Therefore, it is beneficial to eat such plant foods that have a high antioxidant compound content, which will cut down the incidence of certain chronic diseases, for instance diabetes, cancers and cardiovascular diseases, through the management of oxidative stress. Furthermore, berries and other fruits with low-amylase and high-glucosidase inhibitory activities could be regarded as candidate food items in the control of the early stages of hyperglycemia associated with type 2 diabetes.