Study on Edible Starch Films Added Sodium Alginate
|Keywords||Starch film Sodium alginate Mechanical Properties Water Vapor Transmission Rate Transparent oily|
With the increasing awareness of environmental protection , the traditional plastic packaging film can not meet the requirements of the people in the food packaging . Starch is a natural polysaccharide , the wide variety of sources , inexpensive , environmentally friendly materials . In recent years , the use of biodegradable starch material to the preparation of edible packaging film more and more attention , to become a world research hotspot . Glycerol plasticized corn starch , potato starch , pea starch film based exploration and innovation , adding sodium alginate as a reinforcing component to improve the performance of starch edible film . First -forming process to explore using the casting method, coating , and to determine the optimal parameters : corn starch : 100ml solution 5g raw starch , glycerin and starch mass ratio of 1:4 , the sodium alginate join a maximum of 3g heated stirring speed of 120 r / min , 0.09MPa lower degassed 10min , 50 ° C dry film film-forming ; potato and pea starch : 5g native starch in 200 ml of solution , the heating and stirring speed of 180 r / min , degassed 15 min, other conditions were the same as corn starch . By infrared , scanning electron microscopy to study the morphology of the membranes , and test the mechanical properties of the film , the water absorption and water vapor transmission resistance oily to to study sodium alginate starch film performance improvement . The results show that : the presence of strong interaction between the sodium alginate and starch molecules , can form a dense film structure . Adding sodium alginate 3g , starch film tensile strength can be improved more than doubled. Alginate added can be in a certain extent, to increase the water resistance of the potato starch film and pea starch film . The relative humidity of the case , adding sodium alginate can be maintained at a good level of the mechanical properties of the starch film . The water vapor permeability of the membrane increases with sodium alginate added in an amount decreased, resistance oily improve .