Study On Brewing Technology Of Dry Shanlan Wine

Shanlan rice wine is a representative product brewed by the Li ethnic people using a traditional starter.Shanlan rice wine has a unique aroma,subtle flavour and low alcohol content.The aged Shanlan rice wine is characterized by elegant flavor and mellow taste.Dry rice wine is a kind of rice wine with a total sugar content of less than 15g/L,which has excellent storage properties due to its low total sugar content.In this study,two kinds of Shanlan rice named Baikeshanlannuo and Huangganshanlan were used to brewing refreshing Shanlan rice wine.The brewing process of was explored and optimized.This research is expected to provide theoretical support for the development of Shanlan rice wine production.The moisture,starch content,fat and protein content of these two varieties of Shanlan rice were measured,and the Baikeshanlannuo fat content was 1.06g/100 g which was lower than that of ordinary brewing rice.The microstructures of the two types of Shanlan rice were observed using scanning electron microscopy.The internal starch structure of the Baikeshanlannuo was looser and rougher,while that of the Huangganshanlan was more compact and denser.Then,the gelatinization performance test of two kinds of Shanlan rice was performed using a Brabender viscometer.The test results showed that the Baikeshanlannuo had higher thermal stability and low degree of regeneration after gelatinization.The Shanlan rice wine brewing process with Baikeshanlannuo was studied.The screen of suitable starter was performed first.Four kinds of starters and a mixed starter were applied in brewing,respectively.Mixed starter showed the highest saccharification efficiency,and Shanlan rice wine brewed with it gained the highest sensory score.Then the appropriate fermentation process parameters,including the material-water ratio,the amount of starter,the amount of dry yeast,and the amount of acidic protease were studied.Accord to the alcohol content and total sugar of rice wine,the optimal material-water ratio is determined to be 1: 1.In order to achieve better basic physical and chemical indicators,higher alcohol content and higher sensory scores,the optimal amount of starter,protease and dry yeast were determined to be 1.0%,20U/g and 0.6% respectively.To investigate the effect of adding acid protease on Baikeshanlannuo rice to the volatile flavor substances of the finished wine.The gas chromatograph-mass spectrometry was used to determine the differential volatile substances between treated group and control group,and those substances were obtained by orthogonal partial least squares analysis.106 kinds of volatile substances contents in Shanlan wine were significantly different compared with the control group after.Among them,92 kinds of volatile substances contents had increased significantly.(P<0.05).The effects of ultrasonic treatment on the cooking and fermentation properties of Shanlan rice were investigated.These effects were evaluated by multiple physical and chemical indicators via scanning electron microscopy(SEM),low-field nuclear magnetic resonance(LF-NMR),and high-performance liquid chromatography(HPLC).According to the minimal cooking time and the content of total leached solids,the optimal ultrasonic power and time were determined to be 240 W and 30 min,respectively.The results indicated that the ultrasonic treatment broke the rice surface,loosened the inner structure of rice,and extended the relaxation time.These changes increased water absorption during the cooking process by 8.2 % and promoted saccharification and alcohol production at the initial fermentation stage,with a 54.1 % higher alcohol content on the first day.The rice wine brewed from the treated rice showed differences in the non-volatile acid contents;malic acid and tartaric acid contents increased,while the acetic acid content decreased significantly.Moreover,the red colour and brightness of the rice wine were significantly improved after the ultrasonic treatment,with a 16.6 % increase in the rice wine yield.The gas chromatograph-mass spectrometry was used to determine the differential volatile substances between treated groups and control groups,and those substances were obtained by orthogonal partial least squares analysis.158 kinds of volatile substances contents were significantly different from the control group.Among them,89 kinds of volatile substances contents had decreased significantly(P<0.05).