PRESERVATIVE EFFECT OF GELATIN COATINGS ON CARROT

Abstract

Edible coating extends the life span of fresh fruits and vegetables. It is used to preserve food and prevent spoilage of fruits stored at room temperature. Preservative effect of gelatin coatings on the preservation of carrots was analyzed. Gelatin was prepared in four concentrations (0.5 g/ml, 1.0 g/ml, 1.5 g/ml and 2.0 g/ml). It was applied using dipping technique and allowed to dry before storage in sterile containers. Physiochemical parameters, weight loss and microbiological qualities of the coated and uncoated carrots were analyzed for a period of 7 days using standard procedures. Isolation and identification of bacteria was carried out using pour plate method and biochemical tests. Gelatin concentration at 0.5 g/ml attained nutrient retention with moisture content, total soluble solids and protein content of coated carrots ranging from 90.50 ± 0.01 – 85.40 ± 0.00 %, 12.20 ± 0.01 – 10.60 ± 0.00 Brixo and 1.50 ± 0.01 – 0.25 ± 0.01 % respectively. Weight loss of coated carrots at 0.5 g/ml concentration ranged from 0.35 ± 0.01 – 0.25 ± 0.02 g while 1.0 g/ml concentration ranged from 0.35 ± 0.00 – 0.28 ± 0.03 g. The bacterial and fungal counts of carrots coated with gelatin ranged between 0.20 ± 0.01 x 104 - 7.50 ± 0.05 x 104 Cfu/g and 0.20 ±0.01 x 104 – 18 ± 0.01 x 105 Cfu/g respectively. Eight bacterial and five fungal isolates namely Proteus sp., Staphylococcus sp., Enterobacter sp., Escherichia coli, Pseudomonas sp., Aeromonas sp, Bacillus sp, Streptococcus sp, Fusarium sp., Aspergillus niger, Aspergillus fumigatus, Rhizopus stolonifera, Penicillum sp. were the most occurring bacterial and fungal species respectively. Coating with gelatin extends life span, reduce water and helps maintain the phytochemical properties of the carrot.