In this study, the polysaccharides were firstly extracted from the tamarind seeds in which the crude polysaccharides have been extracted once by hot water extraction. The structure was characterized by FTIR, SEM, and X-ray diffraction after removing protein and small molecule impurities. Furthermore, the rheological and bioactivity of tamarind seed polysaccharides (TSP) were also investigated. The results indicated that the yield of the obtained polysaccharide was 3.42%. TSP was mainly composed of glucose (45.09%), galactose (22.80%), and xylose (28.89%), while it contained characteristic structure of polysaccharides, such as –OH, pyranose, and uronic acid at 3,418, 1,150, and 1,040 cm−1 respectively, which demonstrated that it was a uronic acid heteropolysaccharide. Moreover, the XRD pattern revealed the amorphous behavior of TSP, and it was found to consist of films or “sheets” reflected by SEM. The flow behavior testing confirmed its pseudoplastic character, and the flow behavior index (n) was between 0.4539 and 0.9201. The DPPH radical scavenging activity of TSP was 40.34% at 10 mg/mL. Furthermore, TSP displayed moderate hydroxyl radical scavenging and anti-bacterial activities, owing to its special structure and composition. Overall, our results suggested that TSP could be used as a food ingredient with anti-oxidative and antibacterial activities, which provides useful information on the potential utilization of TSP in the food industry.

Background Gout is the second most common metabolic disease affecting human health. The disease of gout is closely related to the level of uric acid, which is the end-product of human purine metabolism. Moreover, food is the main way of external ingestion of purine. Method A simple and time-saving method was developed to extract purines like adenine, hypoxanthine, guanine, and xanthine from marine fish by single factor design combined with Box–Behnken. The contents of these purines in the edible parts and internal organs of marine fish, as well as Scophthalmus maximus, were determined by high-performance liquid chromatography to investigate the relationship between the boiling process and purine content. Result The mixed-acid method was chosen for the extraction of purine bases and the extraction conditions were as follows: mixture acid 90.00% TFA/80.00% FA (v/v, 1:1); hydrolysis temperature 90.00 °C; time 10.00 min; liquid-to-solid ratio 30:1. The total purine content of the edible parts (eyes, dorsal muscles, abdominal muscles, and skin) was the highest in Scophthalmus maximus, followed by sphyraena, Sardinella, Trichiurus lepturus, Scomberomorus niphonius, Pleuronectiformes, Sea catfish, Anguillidae, and Rajiformes. Moreover, boiling significantly reduced the purine content in the marine fish because of the transfer of the purines to the cooking liquid during boiling. Scophthalmus maximus, Sphyraena, and Sardinella were regard as high-purine marine fish, which we should eat less. We also confirmed that boiling significantly transferred purine bases from fish to cooking liquid. Thus, boiling could reduce the purine content of fish, thereby reducing the risk of hyperuricemia and gout.

The problems of spoilage, disease, and biofilm caused by bacterial quorum‐sensing (QS) systems have posed a significant challenge to the development of the food industry. Quorum‐quenching (QQ) enzymes can block QS by hydrolyzing or modifying the signal molecule, making these enzymes promising new candidates for use as antimicrobials. With many recent studies of QQ enzymes and their potential to target foodborne bacteria, an updated and systematic review is necessary. Thus, the goals of this review were to summarize what is known about the effects of bacterial QS on the food industry; discuss the current understanding of the catalytic mechanisms of QQ enzymes, including lactonase, acylase, and oxidoreductase; and describe strategies for the engineering and evolution of QQ enzymes for practical use. In particular, this review focuses on the latest progress in the application of QQ enzymes in the field of food. Finally, the current challenges limiting the systematic application of QQ enzymes in the food industry are discussed to help guide the future development of these important enzymes.