Effect of irradiated chitosan on the rancidity of radiation‐processed lamb meat

Abstract

SummaryWe report here the production of irradiated chitosan and its novel use as a natural antioxidant for minimising lipid peroxidation of radiation‐processed lamb meat. Antioxidant activity of chitosan isolated from shrimp waste was determined by the beta‐carotene bleaching assay and 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) scavenging activity. Irradiation of chitosan at 25 kGy dose of gamma radiation resulted in a six‐fold increase in its antioxidant activity as compared to the non‐irradiated chitosan as measured by DPPH assay. Similarly the reducing power of irradiated chitosan was 6‐fold greater than autoclaved chitosan. The suitability of irradiated chitosan for controlling lipid oxidation of radiation‐processed meat was also investigated. Irradiated chitosan when added to meat before radiation processing was found to be more effective in minimising lipid perioxidation than non‐irradiated chitosan as measured by TBA number and carbonyl content. TBA values of irradiated meat containing irradiated chitosan decreased by 88% (leg) and 54% (rib) as compared to the corresponding sample without chitosan. Further development of post‐processing rancidity was reduced by 39% (leg) and 59% (rib) in the samples treated with chitosan as compared to non‐treated controls even after a week of storage at 0–3°C.