Effect of buckwheat incorporation on batter fermentation, rheology, phenolic, amino acid composition and textural properties of idli

Abstract

The effect of replacement of rice with buckwheat (BW) at levels of 10, 30 and 50% in idli on batter fermentation and rheology, idli textural and nutritional quality was studied. Also, two idli variants containing parboiled rice (PR) and raw rice (RR) were evaluated and compared for the suitability of BW incorporation. Idli batters prepared with PR had higher fermentation activity and yielded batters with higher reducing sugar (RS) and rise in volume. RS content (268.91–467.34 mg/g) was highest for 50% BW incorporated PR batter and lowest for 30% BW incorporated RR batter. The rise in batter volume decreased and titrable acidity increased with addition of BW. Furthermore, with an increase in BW, storage and loss modulus of idli batters increased. All idli batters containing PR had lower tan δ and higher amounts of RS, indicating a greater degree of fermentation which resulted in a light and highly aerated batter. Idlis containing PR had better textural attributes, particularly lower hardness (5.43–8.98 N) than RR idli variants (8.87–9.89 N) and good overall sensorial acceptability. BW incorporation improved the amino acid and phenolic profile and antioxidant activity of idli.