Study On Preparation And Properties Of Edible Films Composed Of Carboxymethyl Cellulose And Cassava Starch

The application of edible films continues to promote in food packaging filed. And the researches of edible films based on modified cellulose were becoming hot topics at home and abroad. In this research, the edible composite films were prepared from carboxymethyl cellulose and plasticized with glycerol by adding cassava starch as an auxiliary material, and the properties of composite films were tested. At last the prepared carboxymethyl cellulose- cassava starch composite films were applied for a period of storage. The optimum addition of cassava was determined through the study of indicators in order to get higher performance of composite film and to provide a theoretical basis for different business applications. The main results were as follows:1,The factors that influence the properties of edible films had been discussed. The optimal process parameters determined by response surface analysis were as follows: 2.5% CMC, 38% addition of glycerol, 1.2 g/cm~2 poured amounts and 50℃drying temperature.2,The research on cassava starch improving properties of carboxymethyl cellulose films showed that the TS and water solubility of the composite films decreased gradually, while E and the transparency of the composite films increased gradually with the addition of cassava starch. Addition of cassava starch kept the pure films'little oil permeation rate. The WVTR of composite films decreased gradually with the addition of cassava starch in the range of 0~15%, which gradually increased while adding more than 15%. It could be concluded, from the properties integrated of the composite films, that the optimal addition of cassava starch was 15%.3,It can be inferred from the microstructure graphs that CMC particles showed rectangle, cassava starch particles showed round and transparent in the middle, and composite films showed dense, uniform and continuous. So it could be concluded that there was a good compatibility between CMC and cassava starch. The appearance of composite films looked smooth and the comprehensive properties were good.4,Application experiments showed that: with the extension of storage time, there was no significant difference of composition change degree of food wrapped by CMC-cassava starch composite films compared with plastic films in 30 days time, contrary to the difference after 30 days, but with little change of the oil peroxide value. We came to the conclusion that the edible composite films prepared were more suitable for storage within 30 days of vinegar and powder packing and long-term oil packing.