Properties of heat moisture treated red rice paddy and its puffed product

Abstract

AbstractBackground and ObjectivesThe present work evaluated how the heat‐moisture treatment (HMT) of pigmented paddy influenced the physicochemical properties on puffing.FindingsPigmented rice paddy was subjected to heat‐moisture treatment at 121°C for 15, 30, and 45 min. The milled grains (HMT_NP) were puffed at 250°C for 9 s (HMT_P). HMT increased amylose content (13.54 ± 0.03 in raw rice to 14.66 ± 0.05 in HMT_NP45) and the reverse trend occurred on puffing (12.34 ± 0.38 in untreated puffed rice to 11.76 ± 0.17 in HMT_P45). Pasting profile of HMT_NP rices showed resistance to swelling and ruptures and increases in tolerance to heat and stress. Pasting temperature increased from 74 ± 0.71a in untreated raw to 81.19 ± 0.34b in HMT_NP45 and from 74.03 ± 0.45a untreated puffed rice to 80.3 ± 0.28b in HMT_P45. HMT_NP samples showed a combination of A and V‐type peaks, while an E‐type starch pattern was observed for HMT_P rices. Crystallinity decreased with treatment time from 30.78 (raw) to 23.03% (HMT_NP45) and from 15.65 (puffed) to 12.29% (HMT_P45) in puffed samples). Puffing of HMT rices increased the viscoelastic property of the samples.ConclusionHMT thus majorly caused strengthening of molecular structure and rigidity which were reversed on puffing. This is the first report on adding value to HMT paddy through puffing expansion.Significance and NoveltyHMT_NP and HMT_P rice samples can have specific end uses in food industries. HMT_P can be particularly useful as viscosity enhancer in powder form, and to impart brittle texture in chocolate‐coated wafers and bars as whole grain.