Study On Browning And Regulation Of Chaenomeles Speciosa S. Nakai During The Processing

Chaenomeles speciosa s. Nakai is a special product from Xuancheng, which is one ofthe famous medicinal and edible plant and the symbolic agricultural products in china. It isrich in value as food and nutritional health function, which has very important significancein deep processing of Chaenomeles speciosa s. Nakai. But the fresh Chaenomeles speciosas. Nakai has many phenolic compounds and enzymatics, so it is easy to be brown inprocessing.The study is based on the fresh Chaenomeles speciosa s. Nakai as the raw material,and to aim at the problem causing brown in processing, and study on the characteristics ofPPO, the change of the related material and the kinds of enzymatic browning substratesfrom Chaenomeles speciosa s. Nakai, the article also discusses the factor of non enzymatic,determination and analysis the change of nutritive proportion in storage, which purpose isexploring the mechanism of Chaenomeles speciosa s. Nakai browning and selecting thebrowning inhibitors which is inexpensive and effective. Based on the control of brownchange, and study the key technology of deastringency and creating a vacuum in theprocessing of Chaenomeles speciosa s. Nakai tin, thus get the best processing parameterand design the most reasonable machining path. The next is the result of the study:1. PPO activity is obviously higher in core than in the peel and flesh, browning inChaenomeles speciosa S. Nakai organization is mainly caused by the polyphenol oxidase;the most suitable substrate of PPO is the catechol; the optimum temperature is20℃, PPOwill be deactivated in80℃for5minites; most suitable pH is5.5, PPO is more stable in theacidic condition than the alkaline condition;It can estimate the chlorogenic acid is one ofthe browning inhibitors substrates by the analysis from TLC and ultraviolet absorptionspectrum.2. During the storage, the activity of PPO and PAL increased and then decreased, itget the max on the ninth day, the content of total phenols is decreased, but it increased onthe ninth day, and the activity of PPO and the content of MAD keep increasing. The resultshows that: the PPO is the major material which can lead enzymatic browning inChaenomeles speciosa s. Nakai.3. Ascorbic acid, L cys, NaHSO3, citric acid and NaCl all can inhibit the activity ofPPO. Based on the study of single factor, the result of the orthogonal factor study showsthat: with0.01%L cys,0.015%ascorbic acid,1.0%NaCl and3.0%citric acid can inhibitenzymatic browning efficiently. So after the mixture inhibitor deal with the Chaenomeles speciosa s. Nakai, the non enzymatic browning is the major factor of the browning.4. The non enzymatic browning will be enhanced with a rise of temperature, and thebrowning speed in alkaline environment is more faster than acid environment, the metalion of Fe³⁺, Cu²⁺, Sn²⁺and light also can enhance the non enzymatic browning, with theglass bottle as package materials is better than vacuum material.The content of total phenols, ascorbic acid and total sugar keep decreasing duringstorage, which correlated negatively the variation of browning, but the reducing sugar and5HMF are contrary, the variation of the content of total phenols and ascorbic acid is themost important factor to influence the browning.5. To get the tin which has special aroma from Chaenomeles speciosa s. Nakai andeats sour and sweet tin by this method that is with0.5%NaCl and0.1%citric acid, keepdeastringency10mins in the temperature of50℃, then with the30%sugar solution keepexhausting15mins under the vacuum degree of0.08MPa.