Antioxidant activities of cereal-legume mixed batters as influenced by process parameters during preparation of dhokla and idli, traditional steamed pancakes

Production of GABA-enriched idli with ACE inhibitory and antioxidant properties using Aspergillus oryzae: the antihypertensive effects in spontaneously hypertensive rats

The present study aimed to develop a fermented food (idli) with enhanced γ-aminobutyric acid (GABA) and angiotensin I-converting enzyme (ACE) inhibitory properties using a GABA-producing fungus.

Changes in ACE inhibitory and antioxidant activities in alcalase treated idli batter and idli after fermentation

Idli is a cereal-legume fermented food consumed widely in India. Fermentation and addition of external enzymes have been suggested as methods for release of bioactive peptides from parent proteins. The present study was aimed at exploring the changes in angiotensin-I converting enzyme (ACE) inhibitory and antioxidant activity of 14 h fermented idli batter treated with alcalase in varied amounts (100-700 U/g batter) kept at 30 ± 2 °C. Various batter parameters along with sensory attributes of cooked idli were assessed. The viscosity (12170-7795 cP) and rise in volume (29-20 mL) of batter decreased with addition of alcalase in the batter when compared with control batter (14130 cP, 31 mL). The free amino nitrogen content and radical scavenging activity of alcalase treated batter exhibited an increase by 2-5 and 2-7 fold, respectively while ACE inhibitory activity showed a decrease in IC₅₀ value (lowest being 52.53 ± 1.12 mg/mL of batter containing 600 U alcalase/g batter) when compared with the control fermented set. The hardness and bulk density values of control cooked idli was 0.59 kg and 0.53 g/cm³, respectively while alcalase treated idlis showed a range of 0.71-1.68 kg and 0.53-0.69 g/cm³. The overall acceptance of idli prepared from alcalase treated batters till 600 U/g batter was judged as 'good' by semi-trained panellists. Moreover, the ACE inhibitory and radical scavenging activity of cooked idli prepared from 600 U alcalase/g batter showed enhancement over the control idli. Thus, alcalase treated idli shows potential to be used as a functional food.

Development of value-added nutritious crackers with high antidiabetic properties from blends of Acha (Digitaria exilis) and blanched Pigeon pea (Cajanus cajan)

Pigeon pea was treated by blanching and used to supplement acha flour for the development of functional cracker biscuits. The flour ratios for acha and pigeon pea were 100:0 (ACC), 80:20 (APC1), and 70:30 (APC2), respectively. The developed cracker biscuits were evaluated for chemical acid compositions, antioxidant, as well as antidiabetic properties. Protein contents of the formulated crackers increased with increase in supplementation with pigeon pea flour. The antinutrient content of the formulated snack was low hence may not adversely affect nutrient bioavailability. Glutamic and aspartic acids were the predominant amino acids while methionine and lysine significantly increased as a result of supplementation with pigeon pea flour. The biscuit exhibited good antioxidant properties indicated by its strong ability to scavenge hydroxyl, superoxide, DPPH radicals, and reduced Fe3+ to Fe2+. The formulated snack especially APC2 possessed low glycemic index (47.95%) and significantly inhibited the key digestive enzymes (α-amylase and α-glucosidase). All parameters evaluated indicated that APC2 could serve as a functional snack in the management of hyperglycemia (diabetes) and prevention of associated degenerative diseases.

Preparation of antinutrients-reduced dhokla using response surface process optimisation

Dhokla, a popular indigenous savoury dish of India, is prepared by soaking bengalgram dal and rice, grinding separately, mixing the batters, and spontaneously fermenting and steaming of mixed batter. Central composite rotatable response surface designs for soaking, fermentation and steaming at five-level combinations were used for optimising preparation of dhokla to achieve reduced contents of antinutrients. Optimum soaking of bengalgram dal (dal-water ratio of 1:5 w/w, pH 7.0, 23 °C, 20 h) and rice (rice-water ratio of 1:5 w/w, pH 5.6, 16 °C, 18 h) resulted in reduced levels of all the antinutrients, except total biogenic amines in rice. Fermentation of dal-rice (3:1 v/v) mixed batter under optimum condition (added NaCl of 8 g/kg, 32 °C, 18 h) further reduced their levels, but total biogenic amines content was enhanced. However, optimum steaming of dal-rice mixed fermented batter for 20 min was effective in reducing all the tested antinutrients. In dhokla, the content of tannins, phytic acid and total biogenic amines reduced by 100, 94 and 20%, respectively; trypsin inhibitor and haemagglutinating activities reduced by 92 and 100%, respectively, over raw ingredients. The optimally prepared product (dhokla) ranked "excellent" in terms of overall sensory quality.