Effect of lemon grass (Cymbopogon citratus) extract and nanoclay in nanocomposite coating on the physicochemical and microbial properties of chicken fillets during refrigerated storage

Formation of nanocomposites in biopolymer coats can provide a new opportunity not only to improve the properties but also to reduce the price of these products. Also, nanocomposites, increase the efficiency of natural antibacterial materials. In order to investigate the antioxidant and antimicrobial effects of lemon grass extract and the amount of nanoclay on the efficacy of alginate-nanoclay composite coating of chicken fillet refrigerated storage, an experiment was performed in a completely randomized design with 6 treatments including alginate (2%) – nanoclay (1.5 and 3%) nanocomposite coating, without and with levels of 1.5 and 3% alcoholic extract of lemon grass and 3 replicates each treatment during 9 days. Results showed that contribution of nanoclay in the structure of nanocomposite coating was affected on its performance. Enrichment of alginate-nanoclay nanocomposite coating with lemon grass extract, added to its efficiency. Applying 3% of lemon grass extract in nanocomposite coatings, especially when using 3% nanoclay, significantly (p<0.05) reduced the number of psychrophilic bacteria, tiobarbitoric acid index, free fatty acids and total volatile nitrogen compounds and increased chicken fillets water holding capacity during refrigerated storage. The contribution of nanoclay in without extract nanocomposite coating, did not significantly affect the number of psychrophilic bacteria at the end of the storage period. In general, the efficacy of alginate-nanoclay nanocomposite coating in increasing the shelf life of chicken fillets in refrigerated conditions depends on the appropriate contribution of nanoclay and enrichment with the appropriate concentration of lemon grass extract.