The Study Of Fresh Style Chinese Rice Wine Brewed By Reducing Solid Content During Post-fermentation Period

Fresh style Chinese rice wine, with characteristics of lightness and elegance, has become more and more popular. On the basis of traditional production technology of Shaoxing rice wine, this study was aimed to develop a new technology for the production of fresh style Chinese rice wine. The new technology was realized by reducing solid content when the previous fermentation ended. The main results are as follows.1.9 different solid reducing amounts were set, respectively 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%.Under which condition, wine is brewed And then,to observe and compare the differences, several indexes were detected during post-fermentation, including reducing sugar, alcoholic strength, total acid and amino acid nitrogen. The results showed that, it was much more appreciate for brewing fresh style Chinese rice wine when the solid reducing amount was 40%-50%, which can not only keep wine quality,but also maintain fresh style.2.Several physicochemical indexes of Chinese rice wine were detected and analyzed, which contained reducing sugar, alcoholic strength, total acid, amino acid nitrogen and protein content. The results showed that 1)there was no significant effect in pH value with the reduction of solid content. 2)the reduction of solid content had regular influence to the content of alcohol, reducing sugar, amino acid nitrogen, protein and total acid. With the reduction of solid content, the content of alcohol, amino acid nitrogen and protein showed decreasing trend, while the content of reducing sugar showed the increasing one.3)the reduction of solid content had a significant effect to the total acid content, which showed increasing trend. In addition, when the reduction of solid content reached more than 60%, the total acid content would be too high, going beyond the range of national standard. Hence, the reduction of solid content should be controlled within proper range, and judging from the results, not more than 60% was advisable.3. To study the organic acids and amino acids in Chinese rice wine brewed by this technology, the content of 5 organic acids, 18 amino acids and 7 volatile aromas as indexes, 10 samples of Chinese rice wine were analyzed by clustering with the software named Unscrambler. The results showed that:1) From the result of analysis of organic acids, the main one was lactic acid, followed by acetic acid, and succinic acid was in lowed level. With the increase of reducing amount of post-fermentation solid content, the content of 5 organic acids basically present increasing trend. The content of 18 amino acids almost showed regular changing trend, which was the decreasing trend with the reduction of solid content, determined by means of high performance liquid chromatography. The aromatic components were detected by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS), the content of which showed decreasing trend with the increase of reducing amount of post-fermentation solid content. These flavor substances contained propyl alcohol, isobutyl alcohol, isoamylol, ethyl lactate, acetic ether, isoamyl acetate and diethyl succinate.2) By clustering analysis of 5 organic acids, three clusters were obtained. One was Chinese rice wine produced with traditional technology and by means of reduction of solid content being 10% to 50%, another was Chinese rice wine produced with the reduction of solid content being 60% and 70%, and the other was 80% and 90%. By clustering analysis of 18 amino acids, we know that, the traditional and the wine with 20% to 40% reduction of solid content came in a cluster, the wine with 50% to 80% reduction of solid content came in a cluster, and the wine with 10% reduction came in a cluster. By clustering analysis of 7 volatile flavor compounds , the traditional and the wine with 20% to 60% reduction of solid content came in a cluster, the wine with 70% to 90% reduction of solid content came in a cluster, and the wine with 10% reduction came in a cluster.4. the Chinese rice wine was analyzed by organoleptic investigation, which showed that there was no significant difference in sensory score of the traditional and the wine with 10%-50% reduction of solid content. when the reduction of solid content reached 40%, the wine was freshest and got the highest score . The wine got low score when the solid content was reduced too much.