Abstract
•A carrageenan based edible film was developed using Aloe vera gel as a bioactive ingredient•The efficacy of the film was evaluated using kulfi as a model of study during six-month frozen storage•The film significantly improved the lipid oxidative and microbial stability of the stored samples•A significant impact was observed on sensory quality of the stored samples indicating potential of the film for commercial applications
The study was aimed at developing a bioactive edible film for improving the lipid-stability of ice-cream and frozen dairy products during storage using Aloe vera as a bioactive ingredient. Kulfi, a popular Indian ice-cream, was used as a food model system. The optimized film (1.5% w/v carrageenan and 14% w/v glycerol) was incorporated with different levels of A. vera (9, 12 and 15% w/v) and used to pack the kulfi samples during six-month frozen storage (-18°C). While density (g/mL) and thickness (mm) of the film increased, the transmittance (%), water-vapour transmission rate (mg/m2t) and lightness (L*) values decreased with concentration of A. vera. The A. vera films showed antimicrobial properties against Escherichia coli. The kulfi samples packaged in A. vera films showed significantly lower values for lipid-oxidation [thiobarbituric acid reacting substances (TBARS), free-fatty acids (FFA) and peroxide values (PV)] and microbial counts (psychrophilic and yeast/moulds) which were reflected in their sensory quality during entire storage period. The highest values for TBARS, FFA and PV were observed for control samples (1.0 mg malondialdehyde/kg, 0.80% and 1.99 meg/kg, respectively) and lowest for samples packaged in films containing 15% A. vera (0.61 mg malondialdehyde/kg, 0.47% and 1.34 meg/kg, respectively) on day 180.