Quality changes and path analysis of color degradation of Dendrobium officinale flower juice during storage

The research was conducted to investigate the quality changes of basic physicochemical indicators, functional components and appearance, such as, pH, total color difference, Browning Index, polyphenols, flavonoids , anthocyanins , VC, and 5-hydroxymethylfurfural content and so on of Dendrobium officinale flower juice (DOFJ) under the dark storage conditions of 4, 25 and 37 °C and the natural light irradiation storage conditions of 25 °C for 8 weeks. Correlation and path analyses were used to analyze the causes of color degradation of DOFJ. Although measures had been taken during the preparation process to inhibit enzymatic browning by deactivating the activity of polyphenol oxidase (PPO), DOFJ was still unstable under four storage conditions, especially for color degradation. With the increase of temperature and time, the basic physicochemical indexes did not change significantly, but the content of functional components gradually decreased, and the appearance gradually deteriorated. The path analysis indicated that anthocyanins degradation was the key factor of color degradation of DOFJ, and low temperature and light protection could delay the degradation of anthocyanins. The main cause of color degradation of DOFJ during storage was identified, which provided a basis for further inhibiting color degradation of flower juice.