苹果汁掺假检测及储藏过程中营养物质变化的研究

应用紫外光谱法结合主成分分析法,对掺入梨汁、甘蔗汁和葡萄糖、果糖及蔗糖溶液的掺假苹果汁进行了快速检测;同时,对苹果汁在室温储藏过程中营养物质的变化进行了研究.实验结果表明:紫外光谱法结合主成分分析法可以较好地检测出掺假的苹果汁,尤其是掺梨汁的苹果汁;苹果汁在室温储藏时,其可溶性固形物、维生素C、黄酮、总糖和还原糖的含量、pH值、抗氧化活性都呈降低的趋势,总酚含量则相对稳定.

Study on the determination of the adulteration of apple juice and the change of the nutrient in the apple juice during storage

A method for quick determination of apple juice mingled with pear juice, sugarcane juice and glu- cose, fructose and sucrose solution was proposed by a UV spectrometry combined with principle component a- nalysis. Changes of nutrients in apple juice during storage were investigated. Results revealed that UV spec- trometry coupled with principle component analysis was a fast economical and accurate method to identify adul- teration in apple juice especially for apple juice mixed with pear juice. During the room temperature storage, the soluble solids, vitamin C, flavonoids, total sugar, reducing sugar content, pH value and antioxidant activ- ity of apple juice were found to be decreased along with the time, while total phenols content was found to be relatively stable. The research provided reference for identification of adulterated apple juice and prolong the storing period of the pure apple juice for the related departments.