Development of a bilayer biodegradable packaging material enriched with coffee waste extract for cake preservation

The study aimed to develop an active packaging, functionalized by spent coffee grounds extracts (SCGE) to preserve cake. The antioxidant extracts were obtained using three extraction methods: conventional extraction (CE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). The SCGE obtained with UAE and MAE produced the highest total phenolic contents and antioxidant activities, and were incorporated into bilayer films composed of polylactic acid, konjac glucomannan, and wheat gluten. The SCGE improved the film's antioxidant activity (8.40 to 90. 56%) and oxygen transmission rate (5.05 ± 0.04 to 2.22 ± 0.13). Active packaging with microwave extracts was more effective in preserving cake's lipids than the ultrasound extracts as measured by the peroxide value, thiobarbituric acid, and acid value during 21 days of storage. Overall, the study demonstrates the potential safe utilization of coffee waste in active packaging.