Effects Of Aging On Lees On The Quality Of Hawthorn Wine

Chinese hawthorn is full of rich nutrition, and has health care value. In our country, the resources of hawthorn are so rich that development of hawthorn wine is not only can stimulate the consumption, increase hawthorn product added value, but also can confirm the development of fruit wine industry policy in our country. But common hawthorn wine is with many faults, such as strong acid feeling, poor stability and unharmonious taste. Because of bad properties of hawthorn wine, the main task of this paper was to have an experiment of aging on lees on the quality of hawthorn wine with the yeast of Saccharomyces cerevisiae CY3079, Saccharomyces cerevisiae var bayanus EC1118, Saccharomyces cerevisiae WET 136, and Saccharomyces cerevisiae GHM. The purpose of this experiment was to analyse the related data of hawthorn wine aging on lees in order to alleviate the hawthorn wine faults, enhance its stability and complex aroma and mellow taste, and to provide theoretical and experimental basis. At the same time, in view of the effects on the hawthorn wine quality by yeast cells in the process of autolysis, EC1118 was studied in different p H conditions of simulated accelerated system. The contents of autolysate was analysed in order to clear the change rule of autolysate released by yeast cells. The main results were as follows:1、After aging on lees, the yeast cell structure was observed with scanning electron microscopy, and it was found that four kinds of yeast were all with different degree of shrinkage and cracking phenomenon, especially for the SIHA 3. So autolyzed yeast cells in the aging stage were happened and some substances were released from the cell.2、The content of reducing sugar was around 3.0~4.0 g/L, alcohol was between 13.1%~13.4%, dry extract was 47.8~49.4 g/L, total acid content was in 18.0~18.8 g/L, and p H value was 3.08 ~ 3.12 after aging on lees by Saccharomyces cerevisiae CY3079, Saccharomyces cerevisiae var bayanus EC1118, Saccharomyces cerevisiae WET 136, Saccharomyces cerevisiae GHM. Besides, the volatile acid had no obvious change during this process. Therefore, there were no big differences with the basic physical and chemical indicators after aging on lees by four kinds of yeast, and the four kinds of yeast hadn’t cause great influence on the basic physical and chemical indicators of hawthorn wine in the aging process.3、The total phenols, tannins, flavone and anthocyanins contents of Hawthorn wine after aging were determined, and it was found that the total phenol contents declined obviously with four kinds of yeast and there were obvious differences between the hawthorn wine which was not aging on lees, however, no obvious differences of total phenol appeared between the different yeast inoculation. The contents of tannin presented stable or slightly upward trend: tannin content was different with different quantity of yeast inoculation amount, and there was not significantly difference between the same yeast of the tannin content. The total flavonoid showed a trend of decline before and after aging on the hawthorn wine, and besides, anthocyanins content in hawthorn wine was no clearly differences before and after aging on lees.4、The aroma components were analysed of the aging hawthorn wine, and it founded that five kinds of aldehyde esters(acetaldehyde, acetic acid ethylester, heptanoic acid ethylester, ethyllactate, caproic acid butylester) were detected after aging of CY3079 and EC1118, while the heptanoic acid ethyl ester was not detected from the yeast of SIHA 3 and GHM. 7 types of alcohols were measured from four hawthorn wine: methanol content in hawthorn wine showed decline with aging on lees, so that it could conclude that yeast had certain adsorption of methanol. Three kinds of volatile acids were checked out: acetic acid, isovaleric acid and heptanoic acid, but there were no significant differences of its content before and after aging and with different adding quantity of yeast.5、Five kinds of acids were detected before and after aging of hawthorn wine, including citric acid, ascorbic acid, succinic acid, malic acid, fumaric acid, and acetic acid. The major acid was citric acid in hawthorn wine, and it accounted for about 60% of the total acid content. After aging, there was no obvious difference in all kinds of acids content between before and after aging, so, the yeast showed no influences on acids.6、It can be found that the sensory of hawthorn wine could be better afer aging on lees. The best quality was SIHA 3, and then was GHM and CY3079, EC1118 was the worst one. The aroma of hawthorn wine was complex after aging on lees of SIHA 3, after aging, it increased the sweet smell of honey, the bitter feeling was disappeared, and the balance was good, so the SIHA 3 was the most suitable yeast with yeast aging.7、The autolysate of Saccharomyces bayanus EC1118 were detected with different p H of a model wine system. It was found that the protease activity increased first and then declined. The contents of α-AN and total nitrogen increased gradually with the time going on; the content of α-AN increased while the total nitrogen decreased with the increase of p H value. Under the condition of different time and p H, the content of phosphorus was different with yeast autolysis release. With the increase of time, phosphorus content showed increasing trend under the condition of the same p H; besides, with the increase of p H value, the content of phosphorus appeared increase. So through the above results, we can infer that in the different simulation system, the number of released yeast was increasing with the increase of time; however, with the increase of p H, its autolyzed degree may have a tendency to slow down.8、The changes of protein content and molecular weight were detected. With the increase of time, under the condition of the same p H, protein content showed a trend of decline. Under the condition of p H2.8, the autolysis of protein content showed the highest in 24 h; at 120 h, the protein content was the lowest. Under the condition of the same time, with the increase of p H value, protein content also showed a trend of decline. Tricine-SDS-Page electrophoresis experiment and gel filtration chromatography method were used at the same time, and small molecular proteins or peptides were found after the autolyzed yeast cells. Electrophoresis experiment found that the protein molecular weight was about 7.78 k Da, 8.38 k Da and 13.34 k Da, and mostly concentrated in the range of < 5 k Da. HPSEC experiment found that the molecular weight of protein was 1~3 k Da and 3~5 k Da which were accounted for about 94% of the total molecular weight.