Effect Of Winemaking Techniques On The Polysaccharide And Polyphenol Composition Of Cider

Cider is a deep processing product of apple,in which so much nutrition such as phenols,amino acids and organic acids have great benefits for human health.In this experiment,Fuji apple was used as raw material to study the effects of different brewing methods(room and heat macertion;pectinase and ?-galactosidase enzyme;fermentation with pomace and juice)on the cider polysaccharides and polyphenols,with an expecting of providing some technical support to the cider industry.The main results are as following:(1)Different winemaking techniques had different effects on the physical and chemical properties of ciders.Higher reducing sugar content,lower pH of cider and higher clarity of the cider fermented with pomace were apparently detected after the addition of pectinase than control ciders.The addition of ?-galactosidase increased the contents of soluble solids and reducing sugar in the ciders fermented with pomace than control cider,which was adverse in the cider fermented with juice for the content of reducing sugar.The addition of ?-galactosidase had little effect on the clarity of ciders.The synergistic effect of heat maceration and enzyme could significantly change the physical and chemical properties of ciders.(2)The compositions and contents of phenolic compounds of 12 kinds of ciders were determined by HPLC.The results showed that different winemaking techniques had different effects on the polyphenol components of ciders.The addition of pectinase increased the contents of total phenolics,caffeic acid,catechin and phloretin in ciders,and reduced the contents of chlorogenic acid and phlorizin in ciders.Meanwhile,pectinase also had the ability of promoting the degradation of phlorizin and chlorogenic acid into phloretin and caffeic acid.The addition of ?-galactosidase significantly increased the contents of total phenol and caffeic acid in ciders and reduced the amount of p-coumaric acid in the ciders fermented with juice.The fermentation with pomace had increased the dissolution of polyphenols from the must.The combination of heat maceration and fermentation with pomace could significantly improve the contents of total phenol,chlorogenic acid and caffeic acid in the ciders.The combination of heat maceration and enzyme could significantly increase the the polyphenol components of ciders.The antioxidant capacity of cider were significantly correlated with most polyphenol components.(3)The polysaccharides of ciders were extracted by alcohol precipitation.The composition of glycosyl residues in polysaccharide were determined by GC-FID method.The results showed that the composition of glycosy residues of polysaccharides in all ciders were same,mainly glucose,followed by arabinose,xylose,galactose,mannose,rhamnose.The polysaccharide components were mannose glycoprotein(MPs)and arabinogalactan(PRAGs).Different winemaking techniques had different effects on the polysaccharide compositions of ciders.At room maceration,the addition of pectinase increased the contents of rhamnose glycosy residues and total polysaccharides and decreased the contents of mannose,glucose and arabinose glycosy residues in ciders.Under the heat maceration,the addition of pectinase reduced the contents of total polysaccharide,PRAGs and galactose,glucose,arabinose and xylose glycosy residues in the polysaccharide of ciders.The addition of ?-galactosidase reduced the contents of total polysaccharides,the glucose,arabinose and xylose glycosy residues of polysaccharides in all ciders,and reduced the PRAGs content in ciders with the room maceration.In different maceration methods,the fermentation with pomace increased the contents of total polysaccharide and some polysaccharide compositions of ciders.The combination of heat maceration and enzyme could significantly change the polysaccharide compositions and contents of ciders.