Metabolomic and transcriptomic analysis reveals the molecular mechanism by which blue light promotes lutein synthesis in strawberry

Carotenoids are an important component of the human diet, and fruit is a primary source of carotenoids. The synthesis and regulation of carotenoids in fruit are important contributors to the formation of fruit quality. In China, strawberry is one of the main seasonal fruits grown in the winter. Previous studies have shown that light has a significant effect on the metabolism of anthocyanins, sugars, and polyphenols in strawberry. However, the understanding of the role of light in regulating the metabolism of carotenoids in strawberry remains limited. This study investigated the effects of blue, red, yellow-green, and white light on carotenoid metabolism in strawberry. Blue light treatment promoted the synthesis of multiple carotenoids, including lutein, compared with the other three treatment groups. The RNA sequencing data revealed that blue light treatment promoted the expression of lycopene ε-cyclase (LCYE), and the transient overexpression of LCYE in strawberry fruit promoted lutein accumulation in strawberry. Overall, the results suggest that blue light can promote the synthesis of lutein in strawberry by inducing the expression of LCYE.     

pH和热处理对负载叶黄素的尼罗罗非鱼分离蛋白乳液贮藏稳定性和体外消化的影响

为了提高叶黄素的稳定性和生物利用率，以罗非鱼分离蛋白(TPI)为乳化剂，高压均质制备负载叶黄素(200μg/mL)的TPI乳液，探讨不同pH (3.0、7.0和10.0)条件下，热处理(70℃，30 min)对乳液粒径、乳析指数、叶黄素含量、体外抗氧化活性和体外消化的影响。结果显示，热处理导致TPI乳液的粒径减小，液滴分布均匀，贮藏稳定性增强。pH3.0时，负载叶黄素的TPI乳液稳定性差，叶黄素降解，乳液色泽明显变化。而在pH 7.0和10.0条件下，70℃热处理不会造成叶黄素降解，4℃贮藏28 d无明显分层。经体外模拟胃肠道消化后，游离脂肪酸释放速率加快，pH 7.0时，经过热处理后，乳液的叶黄素生物利用率由18.65%±1.06%提高至35.69%±2.06%。pH 7.0时，乳液游离脂肪酸释放量和生物利用率达94.22%±0.60%和35.69%±2.06%,ATBS自由基清除能力为59.17%±0.66%。研究表明，在中性和碱性条件下结合热处理可以提高TPI乳液负载叶黄素的稳定性和生物利用率，保护叶黄素的抗氧化活性，为负载叶黄素的TPI乳液的开发及应用提供了参考。