不同冷冻-解冻方式对苹果汁品质的影响

Effects of Different Freezing-Thawing Methods on the Quality of Apple Juice

以苹果汁为供试材料,系统探究不同冷冻及解冻温度对其品质的影响。采用-20、-40、-60、-80℃冷冻温度与4、15、25、35℃解冻温度处理苹果汁,探究不同冻融温度对果汁理化性质的影响。不同冷冻-解冻温度组合对果汁pH值、可溶性固形物含量、可滴定酸含量、褐变度、澄清度、总酚含量、总黄酮含量以及7种多酚组分无显著性影响(P>0.05);冷冻温度对香气成分无显著性影响(P>0.05),而解冻温度对香气成分有显著性影响(P<0.05),主要表现在醛、醇类物质含量随温度的升高而增加,且酯类物质作为主要香气成分在4℃解冻时含量最高,说明低温解冻有利于香气成分的保留。不同冷冻-解冻温度组合对苹果汁品质无显著影响,解冻温度为4℃时可以更好地保留其香气成分。

The effects of different freezing and thawing temperatures on the quality of apple juice were studied.The apple juice samples were treated at the freezing temperatures of-20,-40,-60℃,and-80℃and the thawing temperatures of 4,15,25℃,and 35℃,respectively,and then the physicochemical properties of the juice samples were examined.The combinations of different freezing-thawing temperatures had no significant effects on the pH,soluble solids,titratable acid,browning,clarity,total phenols,total flavonoids or seven polyphenols(P>0.05).Freezing temperature had no significant effect on aroma components(P>0.05),while thawing temperature affected the aroma components(P<0.05).The content of aldehydes and alcohols increased with the increase in thawing temperature,and the content of esters as the main aroma components was the highest at 4℃,which indicated that low temperature thawing was beneficial to the retention of aroma components.Different combinations of freezing and thawing temperatures had no significant effect on the quality of apple juice,and the thawing at 4℃could well retain the aroma components.