Bio-based films prepared with apple pomace: Volatiles compound composition and mechanical, antioxidant and antibacterial properties

The valorisation of agro-industrial by-products can be used as an alternative source for producing healthy food ingredients and materials. The volatile profile measured by headspace solid-phase microextraction-gas chromatography-mass spectrometry, mechanical, antioxidant and antibacterial properties of biodegradable cassava starch film extruded with the addition of different percentages of apple pomace (AP) by-product were evaluated. Characteristic volatile compounds were identified in the samples, such as a-farnesene, sulcatone and ethylphenyl propanoate. The film containing 8% AP had higher total phenolic content (3.32 mg GAE/g, Gallic acid equivalent) and antioxidant activity (2.78 mmol Trolox/g) than the control film (0.71 mg GAE/g and 1.03 mmol Trolox/g). The minimum inhibitory concentration against Staphylococcus aureus, Salmonella thyphimurium, and Escherichia coli for the films containing AP was higher than 12.5 mg/mL for all species. The results suggest that the antioxidant and antibacterial activities and mechanical properties, are dependent on the quantity of the AP added to films. Due to its antioxidant activity and mechanical properties, the AP could have real potential use as a functional ingredient in biodegradable packaging with the advantage of having good antibacterial properties.