浓缩对桑葚汁营养品质的影响

The Influence Concentration to Mulberry Juice Nutritional Quality

为了探讨旋转蒸发浓缩的温度和浓缩度对桑葚汁营养品质和有机酸含量的影响,将鲜榨的桑葚汁于不同温度的条件下进行旋转蒸发浓缩处理,得到可溶性固形物含量为30、40、50、60°Brix的四种浓缩汁,比较分析各复原汁与新鲜桑葚汁的色泽、总糖、花青素、总酚、总黄酮、Vc、5-HMF以及有机酸种类和含量。结果表明:随着浓缩温度和浓缩汁可溶性固形物含量的增加,桑葚复原汁的颜色变暗,色差值△E值逐渐变大,总糖、花青素、总酚、总黄酮和维生素C的含量有所减少,而褐变度和5-HMF含量逐渐升高。桑葚汁中主要的有机酸是苹果酸和柠檬酸,随着可溶性固形物含量的不断增加,有机酸中除了柠檬酸的含量有所增加,其余五种有机酸的含量逐渐下降。综上,旋转蒸发的温度为60℃、浓缩度为50°Brix时能更好的保持桑葚复原汁中的风味营养物质。

Fresh mulberry juice was rotaried,evaporated and concentrated in the conditions of different temperature in order to explore the influence of rotary evaporation concentration to mulberry juice nutritional quality and organic acid content. Take four concentrations respectively includes soluble solids content of 30°Brix,40°Brix,50°Brix,and 60°Brix, and compare and analyze the color,total sugar,anthocyanin,total phenol and flavonoids,Vc,5-HMF,organic acid types and levels between reconstituted juice and fresh mulberry juice. Results indicate that with the increase of concentrated temperature and soluble solids content in the concentrate mulberry reconstituted juice,color darkened;total color difference△E value increased gradually;total sugar,anthocyanin,Vc,total flavonoids and total phenol content have decreased but the 5-HMF content has increased. The main organic acids in mulberry juice are malic acid and citric acid. With the increase of concentrated temperature and soluble solids content in the concentrate mulberry juice,in addition to the citric acid in organic acid content increased,the rest of the five kinds of organic acid content decreased gradually. In conclusion,the mulberries flavor of compound juice of nutrients can be keep better in the condition which temperature is 60℃and concentration is 50°Brix.