Optimizing the texture and retrogradation properties of Niangao (Rice Cake) made with naturally fermented rice flour

Abstract Niangao is prepared from polished round-grained or waxy rice flour and it is a popular and traditional steamed rice cake in China, but its preparation is different. In this study, Niangao was produced with naturally fermented rice flour and the effects of fermentation on physical properties and rheological characteristics were investigated. The results suggest that the water-holding capacity, texture, and color of the samples were significantly improved after natural fermentation, while amylose content was decreased. Additionally, fermentation had a marked effect on retarding the retrogradation of Niangao because fermented Niangao exhibited lower degree of retrogradation compared with the control. Control means Niangao which was produced by unfermented rice flour. Fermented Niangao was harder to be digested than the control was.摘要 年糕（Niangao）是以精磨圆粒大米粉或糯米粉为原料制成的中国传统特色蒸制米糕，但其制备工艺存在差异。本研究以自然发酵米粉为原料制备年糕，探究了发酵过程对其物理特性与流变学特性的影响。结果表明，经自然发酵后，样品的持水性、质构与色泽均得到显著改善，而直链淀粉含量有所降低。此外，发酵可显著延缓年糕的老化回生：相较于对照组，发酵年糕的回生程度更低。对照组指采用未发酵米粉制备的年糕。发酵年糕相较于对照组更难被消化。