Preparation Of Starch-cinnamaldehyde Inclusion Complex By The Ultrasound And Its Application In Polylactic Acid-based Film

Starch is a kind of resourceful and cheaper bioresource. The amylose single helix was formed by adding ligands in the solution. Nevertheless, native starch could not well encapsulate the guests due to the lack of enough surface activity. In order to handle this problem, the ultrasound technique was, therefore, used to prepare starch-cinnamaldehyde inclusion complex in this study. The controlled release behaviors and the migration behaviors in the polylactic acid-based film of the inclusion complex were also estimated. In addition, the polylactic acid-based film with the inclusion complex was also applied to sponge cake packaging.Effects of ultrasound power and time, encapsulation temperature and time, the ratio of host to guest on the encapsulation rate were also investigated. The results obtained under the optimum conditions were addressed as follows: the ultrasound power and time were 250 W and 10 min, the encapsulation temperature and time were 35℃and 12 h, and the ratio of host to guest was 10:1 (g/mL). Under the optimized conditions, the encapsulation rate of the inclusion complex reached 39.54%. The four technologies, including FT-IR, XRD, TGA and DSC, were used to verify the formation of high amylose corn starch-cinnamaldehyde inclusion complex.The releasing behaviors of the inclusion complex were investigated.The results showed that the releasing rate of the pure cinnamaldehyde reached 61.6% in the first week. Nevertheless, the cinnamaldehyde encapsulated by starch was slowly released during the tested period and increased to 62.9% in the end of the fifth week. These results suggest that the inclusion complex could effectively reduce the releasing rate of cinnamaldehyde. Effects of different temperatures (4℃, 25℃and 37℃) and relative humidity(32%, 75% and 98%)on the releasing behavior of the inclusion complex were also studied. The results showed that the release rate of cinnamaldehyde was positively correlated to both of them.The migration behaviors of the inclusion complex in polylactic acid-based film were investigated. Results showed that cinnamaldehyde in the polylactic acid-based film with the inclusion complex migrated in the four kinds of food simulations and the biggest and the smallest migration rate ocuured in 10% ethyl alcohol and isooctane, respectively. Effects of the contents of cinnamaldehyde in the inclusion complex and temperatures on the migration behaviors were investigated, results revealed that the migration rate was positively correlated to both of them.The effect of polylactic acid-based film with the inclusion complex on sponge cake was also studied. As for sponge cakes packaged by polylactic acid-based film without the inclusion complex, numbers of molds exceeded the standard in the forth day. Nevertheless, the sponge cakes packaged by polylactic acid-based film with the inclusion complex became mildewed in the tenth day. These results indicated that polylactic acid-based film with the inclusion complex could effectively prolong the shelflife of sponge cakes.