The effects of gelatin-CMC films incorporated with chitin nanofiber and Trachyspermum ammi essential oil on the shelf life characteristics of refrigerated raw beef

The effects of gelatin-carboxymethyl cellulose (Gel-CMC) based films containing chitin nano fiber (CHNF) and Trachyspermum ammi essential oil (Ajowan), on the shelf life extension of the raw beef at refrigerated temperature (4 °C) over a 12-day period were evaluated. Ajowan essential oil (AJEO) and CHNF were added to the films at 0.24, 0.64 and 1% v/v; and 2 and 4 wt%, respectively. The microbiological (total viable count, psychrotrophic count, Pseudomonas spp., Staphylococcus aureus, lactic acid bacteria, molds and yeasts), the chemical (pH, thiobarbituric acid and total volatile basic nitrogen), color and sensory properties of the packaged samples were evaluated periodically. Bacteria grew the most quickly in the control samples, followed by those wrapped with the Gel-CMC films; The lowest microbial counts, the least change in the chemical properties and the highest sensory scores after 12 days of storage were obtained for the samples wrapped in the films incorporated with 1% AJEO and 4 wt% CHNF. •Effects of Ge-CMC films containing CHNF and AJEO on the shelf life of raw beef were tested.•The films containing 2 and 4 wt% CHNF and 0.64 and 1% AJEO inhibited the count of psychotropic bacterial during 15 days.•The films with 1% AJEO inhibited the growth of Lactic acid bacteria counts almost 2–3 log CFU/g.•CHNF and AJEO led to delay in the lipid oxidation and decomposition of the proteins.•The films containing 4% CHNF and 1% AJEO could prolong the shelf life of the raw beef.