Characterization of biodegradable corn starch-based foam container incorporating kimchi cabbage (Brassica rapa L. pekinensis) by-product

Abstract

The production of synthetic plastics, particularly in the food industry, contributes to an increasing number of environmental challenges. This study aimed at developing a corn-starch-based foam (CSBF) container that incorporates kimchi cabbage (Brassica rapa L. pekinensis) by-product (KCB) from the kimchi manufacturing industry. Through alkaline pretreatment (AP) and air jet milling (AJM) of high-moisture KCB, we observed improvements in cellulose content, crystallinity, water-holding capacity, and particle size reduction. The CSBF container produced using KCB powder processed with AP and AJM (KCB-3 powder) showed decreased thickness and increased density compared to the control (CSBF container without KCB-3 powder). Furthermore, the porous microstructure became more compact, enhancing the container's tensile strength and water resistance. The inclusion of KCB-3 powder resulted in a decreased L* value, accompanied by an increase in the a* and b* values of the CSBF containers. However, when the KCB-3 powder content exceeded 20 wt%, cracks formed and mechanical strength degraded. The residual mass values of the CSBF containers incorporated with KCB-3 powder were significantly higher than those of the control during the soil burial period, indicating a slower biodegradation rate. These findings indicate that discarded KCB has the potential to be a material for biodegradable starch-based packaging containers.