The Lotus Leaf Photochromic Mechanism And Preserving Green Technology

In Hubei Province，there are lots of lotus leaves．Lotus leaf is a natural foodpackaging materials．Lotus leaf as food packaging sensory quality is an importantissue．Lotus leaf chlorophyll is very sensitive to acid，heat，light and oxygen．After harvestlotus leaf is easy to lose the bright green，affected by the oxygen in the air and sunlight intothe olive to brown， serious impact on the use of green lotus leaf in the foodindustry．Therefore，the use of effective preserving green technology，making the lotus leafto be able to maintain a crisp green for a long time．The lotus leaf preserving green is anurgent need to address the problem．Chlorophyll a and b are the two main ingredients make up the lotus leafchlorophyll． On the trend of lotus leaves color，Chlorophyll a present major color trend isblue-green；The main color trends presented by chlorophyll b is yellow-green，Todetermine colorimetric level range according to the ratio of chlorophyll a(greenorientation) and chlorophyll b (yellow orientation)．Lotus leaf is the main raw material，mainly to do the following：（1）pH value of6.00for preserving green lotus leaf optimum pH value．（2）Blanching temperature and time determine：the optimal conditions90℃，for2min．（3）The concentration of the sodium carbonate solution0.08%soak at roomtemperature for30minutes for the best．（4）Sodium carbonate solution at room temperature color protection (peroxidase andpolyphenol oxidase) activity trends，their activity within30min bimodal type．（5）Sodiumsulfite solution concentration of0.08%soak at room temperature for30minutes，Lotus leaf of the green is significantly higher than that of the control6h and12h．Sodium sulfite wandering alone with a reagent sodium sulfite color protection effectis not ideal．（6）Composite sulfur-free color fixative single-factor test：The concentration ofEDTA-2Na150-200mg/Kg；Sodium chloride concentration of the solution is0.4%；Calcium chloridesolution concentration of0.1%-0.3%；Ascorbic acid (VC) concentration ofthe solution was0.08%；Citric acid solution of0.4%concentration of chlorophyll massratio a/b value is relatively high．（7）Zinc acetate mixed green protection at high temperature：After add EDTA-2NaThe effect of preserving green lotus was significantly better than the effect of preserving green is not added．（8）Copper ions at room temperature color protection ineffective．（9）Copper ions mixed green protection at high temperature：After add EDTA-2NaThe effect of preserving green lotus was significantly better than the effect of preservinggreen is not added．（10）Orthogonal test results：Factors influencing the effect of lotus leaf greenprotection of primary and secondary order：copper acetate>citric acid>ascorbic acid>sodium chloride>zinc acetate> EDTA-2Na>calcium chloride．The optimal combinationof parameters：150ppm copper acetate+0.40%citric acid and0.08%ascorbic acid+0.40%sodium chloride+200ppm zinc acetate+150mg/kg EDTA-2Na+0.20%solution ofcalcium chloride color protection，90℃processing2min optimal combination，the effectof preserving lotus leaf green relatively well．（11）Response surface analysis results：150ppm copper acetate+0.38%citric acid+0.07%ascorbic acid+0.39%sodium chloride+150ppm zincacetate+0.20%calciumchloride+150mg/kg EDTA-2Na，processed at90℃for2min for the most Prioritycomposition，the content of chlorophyll a/b of the maximum value of1.365±0.037．（12）Copper acetate solution lotus leaf browning can be fully restored green，Minimum green complex concentration of100ppm；Sodium sulfite solution and zincacetate solution can not make the lotus leaf browning fully restored green，Only frombrownish yellow to brown and white lotus leaf browning．...