Exploring the mechanism of browning of Rosa roxburghii juice based on nontargeted metabolomics

Abstract

To explore the mechanism of Rosa roxburghii juice browning, this experiment was based on nontargeted metabolomics to study the effects of browning on the nutrition, flavor, metabolites, and metabolic pathways of R. roxburghii juice before and after storage. The results showed that the total soluble solids, superoxide dismutase (SOD), vitamin C (VC), total phenol, and total flavonoid of R. roxburghii juice decreased significantly before and after storage. The color difference value ∆E, browning index, and flavor and taste of R. roxburghii juice changed significantly (p < 0.05). A total of 541 metabolites were detected before and after browning of R. roxburghii juice by nontargeted metabolomics, including 435 differential metabolites, of which 221 were upregulated, and 214 were downregulated. The differential metabolites were mainly amino acids and peptides, carbohydrates, and carbohydrate conjugates. There were a total of 76 metabolic pathways enriched by differential metabolites, involving mainly galactose metabolism; alanine, aspartate and glutamate metabolism; and pantothenate and CoA biosynthesis. The experimental results showed that after browning of R. roxburghii juice, VC, total phenol, total flavonoid, and SOD activity were seriously lost, and the flavor deteriorated. The contribution of differential metabolites and metabolic pathways to the browning of R. roxburghii juice was sugar metabolism > amino acid metabolism > ascorbate and aldarate metabolism > phenols.

Changes in phenolic compounds of Phyllanthus emblica juice during different storage temperature and pH conditions

“…), belonging to the family Euphorbiaceae, mainly grows in tropical and subtropical regions of Southeast Asia including China, Indonesia, and Malay Peninsula, and is well known for its medicine and food homology properties (Gaire et al, 2015;Li et al, 2023). It is enriched with vitamin C, behind only to the Rosa roxburghii Tratt, which is known as the "king of vitamin C" in the fruit industry (Liu et al, 2021;Shanmugarajan et al, 2021;Xu et al, 2023). It has a distinctive flavor, great nutritional content, and many physiological effects, such as antidiabetic, hypocholesterolemic, hypolipidemic, antioxidant, anti-inflammatory, immunomodulatory, and memory enhancing (Khurana et al, 2019;Li et al, 2023;Gaire et al, 2015).…”