Heat-sealable bioplastic films of blended locust bean and potato byproducts for active packaging of fatty foods: Cheese and oat cookies as case studies

Fatty foods are very susceptible to lipid oxidation caused by oxygen and light. To minimize this issue, active bioplastic materials are suitable for food packaging. In this work, the feasibility of blending locust bean milling derived dust (LBMD) with potato starch to develop heat-sealable bioplastic films for packaging sliced cheese and oat cookies was studied. Blending LBMD with starch allowed to obtain bioplastic films 2-fold more rigid (Young's modulus of ca. 48 MPa) and 1.3-fold more resistant to water (water contact angle of ca. 87 degrees) than LBMD-based films (Young's modulus of ca. 12 MPa and water contact angle of ca. 47 degrees), maintaining their UV protective capacity. LBMD/starch-based bioplastic films were used to pack cheese, with no molds or yeasts grown after 21 days, similar to petroleum-based plastic packages used as reference. Despite cheese dehydration (ca. 10% weight loss), its texture did not significantly change after the storage period. An increase (ca. 43%) in volatile com-pounds derived from cheese oxidation was observed after 7 days of storage. When used to pack oat cookies, LBMD/starch-based bioplastic films played an active role in decreasing oxidation-derived volatile compounds after 21 days of storage, maintaining their textural properties, when compared to oat cookies packaged with petroleum-based plastic. Therefore, blending LBMD with starch revealed to be a proper strategy to develop heat -sealable and active bioplastic films with water absorption, protection against UV radiation, volatile compounds scavenging capacity, and antioxidant activity suitable to preserve fatty foodstuffs while providing them new characteristics.