New application of smart packaging by using sumac extract for detecting lactic cheese aging

• Chitosan films with sumac extract effectively monitor lactic cheese aging via pH changes. • Incorporating sumac anthocyanins enhances mechanical, antioxidant, and antimicrobial properties. • Developed smart films demonstrate reduced moisture and water vapor permeability compared to controls. • The films display significant color changes, indicating aging with high sensitivity to pH. • Biodegradable films offer innovative solutions for improving food safety and quality. Food consumers are eager to be aware of the quality and shelf life of the food products they buy. The use of smart packaging allows the consumer to know the storage conditions of the package in the past and the current quality of the food inside the package. Changes in food quality can be detected by detecting changes in their pH. In this research, chitosan smart film containing sumac anthocyanin was made by casting method to determine the aging of lactic cheese. Cheese aging is also associated with pH changes. Sumac anthocyanins are sensitive to pH changes and show different colors at different pHs. The properties of the produced smart films such as thickness, opacity, water vapor permeability, antimicrobial properties, antioxidant ability, tensile strength, elongation at break, and especially color changes at different times were investigated. The results showed that by adding sumac extract, the mechanical properties, antioxidant ability, and antimicrobial properties of the films increased compared to the control film (without sumac extract). Also, by adding sumac extract, the moisture and water vapor permeability of the films decreased. The produced films had good antimicrobial properties against Staphylococcus aureus bacteria. The films made changed color after 5 days and lactic acid aged. These films were able to show the aging of cheese by changing its color from brown to pink. These results proved that chitosan smart film containing sumac anthocyanin has the necessary potential and efficiency to monitor the aging of lactic cheese. So, this smart film can be used in cheese packaging.