Screening and Safety Assessment of Volatile Substances in Bioplastic Packaging Bags for Milk Contact

Abstract

Bioplastics hold immense potential to replace fossil-based plastics in the field of food contact materials. However, their application in food contact materials, especially milk packaging, has not undergone extensive safety research. In this study, we conducted screening and migration studies on two types of bioplastic milk packaging bags (primarily composed of a mixture of PLA, PBAT, PBS, and cellulose), comparing their migration into 50% ethanol and real food (including skim milk and whole milk) as migration media. Through screening, we successfully identified seven compounds, including degradation products of antioxidants, lubricants, and plasticizers such as glycerol, diethyl succinate, glycerin, 2,4-di-tert-butylphenol, and 13-docosenamide, in the bioplastic packaging bags. The migration results indicated that the types of compounds and their migration levels into real food were significantly lower compared to their migration into the 50% ethanol simulant. Among them, the migration level of glycerol (68 ± 8 ~ 144 ± 7 mg/kg) in the 50% ethanol simulant group of packaging bag B exceeded the migration limit recommended by the (EU) 10/2011 (60 mg/kg), while in the real dairy group, the migration level of this substance was below the specified limit. The safety assessment results indicate that there is a certain level of safety risk associated with bioplastic packaging bag B. Our study provides crucial insights into the safety of using bioplastics as materials for dairy product contact and the selection of migration test simulants for dairy product contact packaging materials.

Keywords: Bioplastics, Milk packaging bag, Volatile compounds, Specific migration, Real food