No abstract

To promote the industrial production of Chinese rice wine made by enzymatic extrudates, the first is to ensure the consistency of the raw material. That is, an evaluation standard of enzymatic extrudate should be set up. It was studied for the first time. By studying the changes of seven indexes of samples at different sites of extruder barrel and the die along the extrusion direction and making the correlation analysis to select the representative indexes. The results showed that the change trends of dextrose equivalent (DE), molecular weight distribution (MWD) and oligosaccharide composition (OC) were the same, and these indexes were more affected by mechanical force than by temperature. The ability of degradation of different zones was: conveying area < kneading area << exit of the die. There was little difference in extent of gelatinisation (GE) at the temperature where the enzyme activity was relatively high. Different from DE value, water solubility index (WSI) rose gradually. Surprisingly, DE was negatively correlated with GE, and positively correlated with oligosaccharides except DP1 and DP6, and had no significant correlation with water absorption index (WAI) and WSI. In conclusion, DE, WSI, DPD (especially DP6) could be used as a comprehensive evaluation index of enzymatic extrudates.

SUMMARY In view that enzymatic extrusion can change the degradation degree of raw materials, this paper studied the regulation rules of four indexes of degradation degree of enzymatically extruded glutinous rice flour and the correlation between these indexes and the quality indexes of brewed Chinese rice wine. The results showed that at appropriate water content, dextrose equivalent (DE) and water solubility index (WSI) were linearly related to the enzyme content in extrusion with thermostable α‐amylase (TS‐αA) and mesophilic α‐amylase (MS‐αA), respectively. But water absorption index (WAI) was not significantly affected by enzyme content. The percentages of each degree of polymerisation (DP) (1–7) and that of the sum of the rest DPs called other DP were the fundamental reasons for different DE values, WSI, WAI and quality indexes of Chinese rice wine. DP1 was significantly positively correlated with alcohol degree, and negatively correlated with total acid. DP2–DP7 (except DP4) was significantly positively correlated with amino acid nitrogen. Besides, other DP was significantly positively correlated with total sugar and total acid. The percentages of DP1, DP2–DP7 and other DP could be respectively adjusted by changing enzyme content in extrusion with MS‐αA, MS‐αA/TS‐αA and TS‐αA to control the related quality indexes of Chinese rice wine.