Abstract:The objective of this study was to investigate the effects of different vacuum concentration temperatures on sensory quality of concentrated Orah mandarin juice. Changes in color, taste and volatile components of different vacuum concentrated Orah mandarin juice were analyzed by colorimeter, electronic nose, electronic tongue and headspace solid-phase microextraction-gas chromatography-mass spectrometry. The results showed that the color indexes L*、a*、b*、△E and YI of the three kinds of concentrated juices were significantly increased compared with the original juice, while the color indexes b*、△E and YI of the restored juice in the vacuum three-stage gradient cooling concentration group were not significantly changed. The astringency, saltiness and sweetness of the three kinds of restored Orah mandarin juice were significantly lower than those of the original juice. The relative contents of terpenes were higher in the volatile flavor substances of three kinds of concentrated Orah mandarin juice. The relative contents and types of volatile substances in the concentrated juice were changed by heating concentration. In the vacuum three-stage gradient cooling concentration group, the quantity and relative content of hydrocarbons increased by 6 kinds and 22.25%, respectively, and the newly added volatile components, such as β-pinene (9.08%), trans-caryophyllene (2.22%) and β-ocimene (1.17%) gave the juice richer aroma components. The results of comprehensive evaluation and cluster analysis showed that the color and flavor quality of the Orah mandarin juice prepared by vacuum three-stage gradient cooling concentration could be preserved well.
