Protein and polyphenols involved in sediment formation in cloudy litchi juice
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Sedimentation is a major issue in juice production. This paper aims to study the mechanisms of precipitate formation during the storage of cloudy litchi juice. The sediment concentration, relative turbidity, and ζ potential were analyzed. The supernatant and sediment were separated to determine the contents of proteins and phenolics. The results showed that the amount of sediment increased during the storage. In addition, the total protein and total phenolic content in the supernatant decreased, whereas the glutelin and total phenolic contents in the sediment increased significantly (p < 0.05). Moreover, our results showed that the amounts of procyanidin B2 and quercetin-3-O-rutinose-7-O-rhamnoside in the supernatant decreased noticeably. However, these two substances could not be detected in the sediment. In summary, the formation of sediment from litchi juice is mainly caused by the slow denaturation of proteins and the oxidation of procyanidin B2 and quercetin-3-O-rutinose-7-O-rhamnoside.
KeywordsCloudy litchi juice Sediment formation Protein Polyphenols Glutelin
This work was supported by the National Natural Science Foundation of China (No. 31501541), the Natural Science Foundation of Guangdong Province (No. 2015A030312001), and the Science and Technology Program of Guangdong Province (No. 2017B020207005), China.
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Conflict of interest
The authors declare that they no conflict of interest.
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