Developemnt of Mixed Fruit Nectar and their Quality Assessment During Storage

Abstract

Experimental studies were conducted for the production of mixed fruits nectar beverage and their quality assessment. The quality attributes comprised of acidity, pH, optical density, TSS, ascorbic acid, total plate count and sensory quality parameters on 9- point hedonic scale. Evaluation of quality parameters were done for fresh as well as stored nectar beverage samples at 0, 15, 30, 45, 60, 75 and 90 days of storage under different storage conditions. Nectar of pineapple and papaya samples were packaged in glass bottles. The TSS and acidity of nectar beverage increased with decrease in the level of pineapple juice ratio during different storage condition and the optical density decreased with decrease in the level of papaya juice ratio. The pH decreased with increase in the level of papaya juice and pH values of the samples composition 80:20, 70:70 and 50:50 after 90 days of storage were observed as 1.70, 1.65 and 1.50 respectively, under refrigeration during storage condition. The total plate count (TPC) of the nectar beverage samples of different pineapple and papaya juice ratio of 80:20, 70:30 and 50:50 were observed as 1.045x105cfu/ml, 1.046x105cfu/ml and 1.047x105cfu/ml under refrigeration condition after 90 days. The microbial growth increased during storage period irrespective of pineapple juice ratio during different storage condition. The vitam in-C (ascorbic acid) of the nectar beverage samples were decreased during storage period. It might be due to the oxidation or irreversible conversion of L-ascorbic acid into dehydro ascorbic acid in the presence of enzyme ascorbic acid oxidise (ascorbinase) caused by trapped or residual oxygen in the glass bottles. The minimum ascorbic acid of the sample of juice ratio (pineapple and papaya) 80:20, 70:30 and 50:50 after 90 days of storage were observed as 1.90, 1.67 and 1.50 respectively, under refrigeration condition during storage. The highest overall acceptability score of nectar beverage was 8.0 in the ratio of 50:50 under refrigeration (5.c) condition during storage. The lowest value was found 5.5 of overall acceptability in 80:20 ratio under room temperature during storage after 90 days. The sensory quality decreased with increase in storage period. It was concluded that refrigeration storage method was found to be superior in the comparison of other storage methods of pineapple and papaya based nectar beverage followed by BOD incubator at 25·c and room temperature during storage.