Storage stability of raw chevon chunks packaged in composite, bioactive films at refrigeration temperature

Abstract

Storage stability of raw chevon (goat meat) chunks wrapped in preformed, bioactive, biodegradable films based on composite starch–chitosan and impregnated with nisin (60 000 IU/g; T-1) and cinnamaldehyde (0.5% v/v; T-2) was evaluated relative to unwrapped product (control) under aerobic refrigeration (4°C ± 1°C) conditions for 10 days. Samples were taken on Days 1, 4, 7 and 10 to assess various physicochemical, microbiological and sensory quality parameters. Water activity and pH of raw chevon chunks followed a decreasing trend during storage under all packaging conditions; the rate of decrease of water activity was higher (P < 0.05) in the control than in bio-packaged products. Values of thiobarbituric acid reactive substances increased throughout storage and were lowest in T-2 and highest in the control. Extract release volume decreased throughout storage under all packaging conditions; however, it was higher (P < 0.05) in bio-packaged products than the control. Microbial quality was better in bio-packaged products than the control throughout storage. Standard plate count was 2.09 log10 cycles lower in T-2 than the control, and coliform count was lower by log10 2.31 cfu/g in T-2 and log10 1.88 in T-1 than the control on Day 7 of storage. Staphylococcus counts were lower (P < 0.05) in bioactive-packaged products than the control throughout the storage period. Sensory quality attributes colour, odour, texture and overall acceptability were better maintained in bio-packaged products than the control during storage, and maximum scores were awarded to T-2. The results indicate that starch–chitosan composite films impregnated with cinnamaldehyde can be used for the packaging of raw goat meat and successfully extend storage life by inhibiting the colour, oxidative and microbial deteriorative changes under refrigeration.