This study systematically analyzed the changes in the contents of total carotenoids and individual major carotenoids, color, and odor during the processing of Lycium barbarum L. puree. Furthermore, samples from different processing stages were collected to evaluate their inhibitory effects on α-glucosidase and α-amylase activities. Furthermore, the correlation between zeaxanthin dipalmitate (ZDP) content and color, odor and biological activity was explored. The findings demonstrated that the contents of total carotenoids and the core component ZDP significantly increased from the crushing to the homogenization stage, attaining their maximum levels (128.96 and 46.77 mg/100 g, respectively) following homogenization. After sterilization, the contents of total carotenoids and ZDP declined by 25.47% and 13.94%, respectively. As processing progressed, the L*, b*, and C values increased, and the a* value reached its maximum at the homogenization stage. Following sterilization, the a* value decreased by 13.59% while the b* value increased by 8.51%. These alterations were consistent with the changes in total carotenoid and ZDP contents. Across different processing stages, the odor profile remained unchanged except that the responses of sensors W1W (sulfides), W2S (aldehydes and ketones), and W1S (methane) varied. The homogenized sample had the most significant inhibitory effect on α-glucosidase and α-amylase (inhibition percentages of 83.85% and 66.40%, respectively). However, it was observed that the inhibitory activity against both enzymes declined following sterilization. Correlation analysis showed a positive correlation between the content of ZDP and L*, a*, and b* values, as well as the odor response values of W1S and W2S. Furthermore, a positive correlation was observed between ZDP content and α-glucosidase and α-amylase inhibitory effects. The findings of this study suggest a close correlation between changes in carotenoid contents during the processing of L. barbarum L. puree and the quality characteristics of the final product, indicating the importance of carotenoids as an indicator for evaluating its processing quality. These findings provide a theoretical basis for the processing optimization, shelf-life extension and sensory quality improvement of L. barbarum L. puree.

Lycium barbarum L. is traditionally used as a medicinal and food resource in China. Spray dried powder of its fresh fruits is widely used as a food product or a functional food ingredient. In this study, the immunoregulatory effects of Lycium barbarum L. powder (LB), Lycium barbarum L. polysaccharides (LBP) and their mixture (LB + LBP) on cyclophosphamide (CTX)-induced immunosuppressive mice were investigated, as well as their influences on gut microbiota homeostasis. The results showed that LB, LBP and their combination restored the body mass and food intake of immunosuppressed mice to different degrees, improved spleen, thymus and colon injury, effectively promoted the secretion of cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interferon-γ (IFN-γ) and immunoglobulin (Ig) A in immunosuppressed mice, regulated the expression of immune-related genes in the colon, promoted the generation of short chain fatty acids (SCFAs), significantly modulated the relative abundance of Muribaculaceae_unclassified, Muribaculum, Mucispirillum, Helicobacter, Bilophila and Clostridiales (P < 0.05), and reversed the abnormal metabolic function of the gut microbiota induced by CTX. Moreover, compared with LBP, LB and LB + LBP decreased the relative abundance of Clostridiales and increased the relative abundance of the beneficial bacterium Duncaniella, and LB + LBP also decreased the relative abundance of Anaerotruncus. The results of this study will provide a theoretical basis for the research and development of specific health products and diversified products in the Lycium barbarum L. processing industry.

In this study, the changes in total polyphenols, total flavonoids and chlorogenic acid contents during the processing of Lycium barbarum bud tea were compared and analyzed, and the metabolite composition of the tea at different processing stages was systematically analyzed by widely targeted metabolomics to clarify their effects on the chemical composition of L. barbarum bud tea. The results showed that L. barbarum buds had the highest contents of total polyphenols, (43.65 ± 3.15) mg/g, total flavonoids, (10.68 ± 0.25) mg/g, and chlorogenic acid (5.24 ± 0.52) mg/g. The contents of these phenolic substances decreased significantly (P < 0.05) as bleaching, primary fixation, secondary fixation, frying and flavoring progressed. Notably, after the secondary fixation, the contents of total polyphenols, total flavonoids and chlorogenic acid decreased by 19%, 29% and 27%, respectively. Widely targeted metabolomics identified 594 metabolites belonging to 11 categories, including flavonoids, phenolic acids, alkaloids, amino acids and their derivatives, and lipids. In total, 270, 287, 298, 295, and 298 significantly differential metabolites were identified in L. barbarum buds versus bleaching, primary fixation, secondary fixation, frying and flavoring, respectively, with the major ones being flavonoids, nucleotides and their derivatives, phenolic acid, amino acids and their derivatives. These differential metabolites were predominantly enriched in metabolic pathways such as purine metabolism, niacin and nicotinamide metabolism, cysteine and methionine metabolism, and a small proportion of them was enriched in pathways like zeeatin biosynthesis, and ABC transporter. Significant differences were observed in inosine, homocysteine, cinnamic acid, 4-hydroxy-3-methoxycinnamic acid, and isoferulic acid among processing stages, indicating their involvement in the quality formation of L. barbarum bud tea during processing. The findings of this study provide a theoretical basis for understanding the changes in nutritional and functional components and for the quality control of L. barbarum bud tea during processing.