Comparison of coating and nano-coating of chitosan- Lepidium sativum seed gum composites on quality and shelf life of beef

Abstract

Due to the side effects of artificial preservatives in meat products, the use of natural preservatives has increased. The aim of this study was investigated the effect of coating and nano-coating of chitosan (C)- Cress (Lepidium sativum) seed gum (CSG) on the shelf life of beef during 18-day at cold temperature. For this purpose, composite coatings including 33% C:6% CSG, 50% C:50% CSG, 66% C:33% CSG were prepared. The nano-coating was also constructed using ultrasound method. Antioxidant and antibacterial properties were measured and the results showed that the antioxidant and antimicrobial activity of the coatings incremented with increasing C content (66% C:33% CSG) and the antimicrobial and antioxidant activity of nano-coating was significantly higher than the coating (p < 0.05). In order to study the effect of coatings on the shelf life, four treatments including control, coating (66% C:33% CSG), nano coating (66% C:33% CSG) and sodium nitrite were prepared and chemical (peroxide value and total volatile nitrogen) and microbial parameters (total viable count, psychrotrophic count, Pseudomonas aeruginosa and Staphylococcus aureus) were studied at − 2, 4, and 8 °C for 18 days. Synthetic and natural preservatives delayed lipid oxidation and improved the chemical properties in beef. Also, microbial spoilage was significantly reduced compared to the control (p < 0.05). The nano-coating performed better than other treatments in all experiments (p < 0.05), and reduced the growth of pathogenic bacteria from the third day to the end of the period to below the permissible limit. Therefore, it seems that the nano 66% C:33% CSG can be used as a safe preservative in the active packaging of beef during refrigerator and freezer storages.