| A new and edible coating was formulated with corn starch as main ingredient, and other different assistant ingredients such as Glycerol, Tween20 and Hexadecanoic acid. Through the orthogonal experiment and the data range analysis, we got the factor level, average value and the best formation of the corn starch coating. Through SAS software to draw the response surface diagram, we could get the best optimal craft parameter of the corn starch coating. We used the best group of the orthogonal experiment to compare with an Australia polysaccharide edible coating in physicochemical indicators and cost. The result showed:(1) After the cherry tomato (cv. Xiaofengxian) was stored for 42 days at the temperature of 12±1℃and the humidity of 80%～85%, we got the best corn starch coating formation was 3.0% corn starch, 3.0% glycerol, 0.015% Tween20 and 2.0% hexadecanoic acid, i.e. the group 5 (A2B2C3D1)of the orthogonal experiment. At the same time we used the methods of sense estimation in this experiment, the same result was got just as what the data range analysis showed before.(2) Through SAS software to draw the response surface diagram, we synthesized organoleptic evaluation index (the sum of the sense quality index and internal quality index) as final evaluation index after 42 days'storage of the cherry tomato. we studied the effect of different dextrinization temperatures, dextrinization times and the mixing speeds on the coating in fresh-keeping of the cherry tomato, and determined the optimal craft parameters of the corn starch coating, the result showed that the optimal craft parameters were the dextrinization temperature at 75℃, the dextrinization time for 15 minutes and the mixing speed at 300rad/min.(3) We used the group 5 (A2B2C3D1, i.e. 3.0% corn starch, 3.0% glycerol, 0.015% Tween20 and 2.0% hexadecanoic acid) of the orthogonal experiment and an Australia polysaccharide edible coating which was used widely to coat the cherry tomato separately. After 42 days'storage, the result showed that the corn starch coating agent was as effective as Australia polysaccharide edible coating in physicochemical indicators, but at the cost analysis, the corn starch coating was much cheaper than Australia polysaccharide edible coating, which further illustrated that the corn starch coating agent had broad development space on the agricultural market in China(4) Because of the high moisture content and perishability, the fresh cherry tomato was also called "overnight depression fruit". At the same time the storage life was short and the nutrients such as VC etc. are easy to decrease during storage, which made the fruit loss the value of the goods. During the peak season, the cherry tomato lost a lot, but during the off-season, the supply of cherry tomato couldn't meet the demand of market, This study showed that the storage life of Zhangzhou cherry tomato, treated with the corn starch edible coating, was extended for 18 days compared with the CK group, with little loss in their nutritional value, flavor and the value of the goods. It would solve the problem of long-distance transportation, reduce the losses for producers and operators, provide safe and high-quality fruit for consumers, provide practical and easy fruit postharvest technology for farmers, bring considerable economic benefits for the enterprise, and it would have a long-term economic and social benefits. |
