Making the reuse of agro-industrial wastes a reality for starch-based packaging sector: A storage case study of carrot cake and cherry tomatoes

Abstract

Cassava inner bark (CIB) and grape stalks (GS), residues from agro-industrial activities, were applied in the development of biodegradable foams by thermocompression. The samples produced with untreated stalks (sample GSWT) and with stalks only physically treated (sample GSP) presented good mechanical strength (2.1 MPa and 2.5 MPa, respectively) and low water absorption capacity (58% and 56% at 90 min, respectively). Therefore, these samples were selected for the storage of carrot cake and cherry tomatoes. Compared with the cakes stored in the supermarket packaging, there were no significant moisture content differences of the cakes stored in the biodegradable packaging developed by the formulation with the GSP sample (25% and 23%, respectively). The cakes' hardness increased up to 88% when stored in S + CIB + GSWT foam. More interesting, it was observed that the biodegradable packaging is more suitable for the storage of cherry tomatoes than the supermarket ones once the firmness of this product was maintained during storage (initial firmness of 5.4 N and final firmness of 5.3 N after 15 days in S + CIB packaging). Thus, biodegradable packaging developed from agro-industrial residues (CIB and GS) can be considered environmentally-friendly and promising materials to preserve the quality and freshness of carrot cake and cherry tomatoes.