Soluble and bound phenolic compounds were extracted from different varieties of millet types namely, finger millet, foxtail, and proso millet cultivated at dry and intermediate climatic zones in Sri Lanka. The extracts were examined for their total phenolic content (TPC), total flavonoid content (TFC), and proanthocyanidin content (PC). The antioxidant activities were meassured by reducing power (RP), trolox equivalent antioxidant capacity (TEAC), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion chelating ability (FICA), and using a β carotene linoleate model system. The ferulic acid content of extracts were determined using high‐performance liquid chromatoghraphy (HPLC). Finger millet showed the highest phenolic content and antioxidant activities compared to proso and foxtail millets. The phenolic content as well as antioxidant activites of soluble and bound phenolic extracts of millets were affected by variety and cultivated location. The highest phenolic content and antioxidant activites were reported for millet samples cultivated in areas belonging to the dry zone in Sri Lanka.

Finger millet flour was used to prepare five different foods using steaming, pressure cooking, dry roasting and open boiling as representative preparation methods. The soluble and bound phenolics of freeze dried foods were extracted. The gastric and intestinal bioaccessibility and potential absorption of phenolic compounds of foods were determined accommodating a simulated in vitro digestion model. The phenolic extracts of foods and supernatants collected at different stages of in vitro digestion were examined for their phenolic contents and antioxidant activities. The content of ferulic acid, of phenolic extracts of foods were determined using high performance liquid chromatography (HPLC). The open pan boiling retained higher content of phenolics and showed higher antioxidant activities compared to other food preparations. The release of phenolic compounds increased stepwise from gastric to intestinal phase for all foods and the bioaccessibility and potential absorption of phenolic compounds depended on the food preparation methods.

Popsicle-type edible ice cream is consumed worldwide for its sensory properties. However, its nutritional composition is limited to carbohydrates, sweeteners and synthetic flavors. In this work, the objective was to develop popsicles manufactured with different protein sources (rice protein, concentrated bovine milk whey protein and a mixture of both proteins) and added with an herbal lyophilized extract (LME) composed of white tea, fermented rooibos, and roasted yerba mate. Six formulations were produced and their proximate composition, physicochemical properties, sensory acceptability, total phenolic content, condensed tannins, and in vitro antioxidant activity determined. Popsicles added with LME showed a higher total phenolic content compared to the controls (without LME). The popsicles formulated with animal protein and LME showed the highest antioxidant activity as measured by the DPPH and FRAP assays. In relation to sensory analysis, the highest acceptance rates, 91 and 88%, were observed in formulations added with animal protein without and with LME, respectively. On the other hand, the vegan formulation added with LME had the lowest acceptance rate (69%). Overall, the addition of LME and concentrated bovine whey protein provides a viable option for the development of phenolic-rich protein-based popsicles.

Finger millet flour was used to prepare five different foods using steaming, pressure cooking, dry roasting and open boiling as representative preparation methods. The soluble and bound phenolics of freeze dried foods were extracted. The gastric and intestinal bioaccessibility and potential absorption of phenolic compounds of foods were determined accommodating a simulated in vitro digestion model. The phenolic extracts of foods and supernatants collected at different stages of in vitro digestion were examined for their phenolic contents and antioxidant activities. The content of ferulic acid, of phenolic extracts of foods were determined using high performance liquid chromatography (HPLC). The open pan boiling retained higher content of phenolics and showed higher antioxidant activities compared to other food preparations. The release of phenolic compounds increased stepwise from gastric to intestinal phase for all foods and the bioaccessibility and potential absorption of phenolic compounds depended on the food preparation methods.

Finger millet porridges (FMP), rich in nutrient and non-nutrient compounds have been used in the traditional food cultures in Asia. The aims of the study were to determine the effect of different processing conditions of finger millet grains on glycemic response, phenolic content and the antioxidant activities of FMP and to determine the short term and long term efficacy of its consumption on plasma antioxidant levels of healthy adults. Twelve types of FMP were prepared combining different processing conditions. Phenolic content of porridges as well as antioxidant activities were determined. The glycemic index (GI) and glycemic load (GL) values of FMP were also evaluated. The long term efficacy of FMP consumption on plasma glucose (PG), total cholesterol (TC) levels and plasma antioxidant capacity (PAC) of 18 subjects were investigated using a 24 weeks randomized cross-over study. The short term efficacy of porridge consumption on AC was determined. PAC was measured by trolox equivalent antioxidant capacity (TEAC) and ferric ion reducing antioxidant power (FRAP). All FMP exhibited low GI values (< 55) except the raw roasted flour which showed high and medium GI values for both particle sizes used. Parboiling of finger millet grains with 15 min steaming produced FMP with low glycemic response and possessed high PAC. Compared to baseline, PAC measured using FRAP and TEAC assays increased after 8 weeks consumption of porridge though significant changes were not observed for PG and TC levels. Furthermore, PAC was increased by 23 and 14% after 2 h of porridge consumption as measured by TEAC and FRAP, respectively. FMP consumption increased the plasma total antioxidant capacity of healthy adults. Further research on examining the potential of FMP on improving the antioxidant capacity in patients with diabetes is warranted.

Finger millets are important coarse grains that exhibit high levels of phenolic compounds and antioxidant activities among other cereals. Grains are subjected to a number of thermal treatments and this could affect the contents and bioactivities of phenolic compounds. The aim of the present study was to determine the phenolic contents and antioxidant activities of finger millet flour and foods, namely porridges and Pittu subjected to several thermal treatments such as roasting, parboiling, and parboiled roasting of flour and open boiling and steaming of foods prepared using flour. The effect of the addition of spices on phenolic content and antioxidant activities to open boiled foods was determined. Antioxidant activities of phenolic extracts obtained from finger millet flour and foods were studied for their total phenolic, flavonoids and proanthocyanidins contents, radical scavenging capacities, reducing power, ferrous ion chelating capacity, and antioxidant activity in a β-carotene/linoleate emulsion. The roasted flour and foods had higher total phenolic content (TPC) than other counterparts and ranged from 21.58 to 28.63 µmol ferulic acid equivalents/g dry matter. All flour and food preparations exhibited effective inhibition of radicals, reducing power, ferrous ion chelating activity, and antioxidant activity in the β-carotene/linoleate emulsion and the degree of activity depended on the processing conditions adopted in food preparations.Foods prepared using steaming showed lower phenolic content and antioxidant activities in general than those of open-boiled counterparts. The addition of spices, namely garlic and cinnamon improved the phenolic contents and antioxidant activities of open-boiled porridges. The knowledge generated from this study may help to exploit the use of finger millets as a functional food ingredient to promote health and wellness. Graphical abstract

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