Research On Mechanism Of Honeysuckle Color Degeneration In Hot Air Drying And The Rejection

Honeysuckle belongs to a class of caprifoliaceae honeysuckle genus bud, which is one of important Chinese traditional medicine. It Has alleviates fever the disintoxicating and anti-microbial function。At present the most common drying methods used for honeysuckle is hot-air drying. However, honeysuckle appeared color deterioration phenomenon in drying process. The state administration for medicine and health established 4 standards level for honeysuckle products quality, in which color and lustre is one important judgment standard for its rankings. Therefore, whether the color of honeysuckle is deteriorated or not decide its product quality.In this paper, the factors influence honeysuckle color deterioration during drying was studied. The correlation coefficient between the degree of honeysuckle browing and the content of phenols is 0.9923.the correlation coefficient between the degree of honeysuckle browing and the content of chlorogenic acid is 0.972.the enzyme play an important role in the honeysuckle browing process.The effect of cell integrity on color deterioration was also investigated. The results showed that the deterioration of honeysuckle during drying process was a kind of reaction catalyze by enzyme. The optimum temperature of honeysuckle PPO is 50℃,the optimum pH is 6~7,the heat stability is that PPO would be inactivated when it was heated in 60s at the temperature of 100℃.The restraining effects of inhibitors on honeysuckle polyphenol oxidase were as follows: sodium hydrogensulfite > ascorbic acid > citric acid.The degree of honeysuckle browning was different when using different drying methods. Honeysuckle head occurred enzymatic browning obviously in the microwave drying process. The browning degree was slight, the colour was close with fresh honeysuckle and content of chlorogenic acid was high. The browning degree was slight at low heat-air temperature. The dry time become shorter and the browning degree was much slighter with a much longer drying process or at a higher dry temperature. The browning degree was most serious when temperature was 50~60℃.When the hot-air temperature was high, the honeysuckle cell broke easily and ruptured the enzyme and substrate regional distribution. High temperature had no significant effect on the browning degree when the cell had little moisture content. Through changing the temperature in the drying process, it was effective to obtain good honeysuckle with shorter the drying time.The optimal drying process scheme was proposed through identfyirming and analyzing the browning mechanism in the drying process. It provides the theoretical foundation of honeysuckle research and had practical significance for its drying process.