Protein and polyphenols involved in sediment formation in cloudy litchi juice

Abstract

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 f 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 B 2 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 B 2 and quercetin-3-O-rutinose-7-O-rhamnoside.

Ultrasonication of Thawed Huyou Juice: Effects on Cloud Stability, Physicochemical Properties and Bioactive Compounds

“…Zeta potential characterizes the charge of the particle surfaces, affecting the precipitation of juice [41,42]. Research has shown that the stronger the surface charge, the greater the repulsion between particles, and the lower the tendency for aggregation between particles [10,11,42,43].…”

Evaluation of quality changes of differently formulated cloudy mixed juices during refrigerated storage after high pressure processing

“…Shortly after juice extraction, coarse particles settle out immediately by gravity, while fine particles remaining in suspension ( Genovese and Lozano, 2006 ). However, numerous chemical and biochemical changes occurring during shelf-life lead to cloud loss of MJs, such as possibly molecular polymerization, molecular interactions, and pectin cross-links ( Hurtado et al, 2019 ; Zeng et al, 2019 ).…”

Gums—Characteristics and Applications in the Food Industry

“…They are used as adhesive materials in wood-based industry, and obviously, in adhesive industries in general [91]. Gums have applicability in the pharmaceutical area as emulsifiers and reducing agents for suspended particles, laxatives, in the preparation of antiseptics, binders for tablets and pills, and in the cosmetics area (perfume fixers, skin cleansers, and repellents) [92][93][94][95]. Also, in the medical field, gums are used to control osmotic pressure, in addition to having activity against Leishmania amazonensis and antifungal properties [96].…”

“…Carrageenan gum, xanthan gum, guar gum, sodium alginate, carboxymethyl cellulose, gum arabic, and pectin were tested to prevent the formation of turbidity, caused by protein-polyphenol complexation, in packaged beverages. Among them, pectin, xanthan gum, and guar gum showed the best results [94]. These polysaccharides, when present in low concentrations: 0.5, 0.05, and 0.01 mg/mL, compete with proteins to bind polyphenols, which decrease protein-polyphenol aggregation; or they can form a ternary complex (protein-tannin-polysaccharide) to increase the solubility of protein-polyphenol systems.…”