Production and Assessment of Probiotic Fruit Juice from Punjab Pink Variety of Guava

Probiotics are considered as live microbial formulations exhibiting health benefits related to their ability to alter the gut microbiota and thereby preventing diseases. The present study was conducted to produce probiotic guava juice in a pilot plant (batch type, 50L capacity) through the application of Lactobacillus acidophilus (MTCC no. 10307). The probiotic cells of Lactobacillus acidophilus were added aseptically into the guava juice at 15% (v/v) to reach a concentration of 108–109 CFU/ml and bottling was done using pneumatic bottling unit. The physiochemical (pH, TSS, total sugars [reducing and non-reducing], titratable acidity, antioxidant activity, content of lactic acid and ascorbic acid), microbiological and sensory parameters were analyzed. Among the physiochemical parameters a significant decrease was observed in pH 5.62 to 3.99, TSS from 15.11°brix to 13.45°brix, total sugars from 6.78% to 3.23%, reducing sugar content from 3.46% to 1.62%, non-reducing sugars from 3.32% to 1.60%, content of ascorbic acid from 167.25 mg/100ml to 160.01 mg/100 ml and antioxidant activity from 43.82% to 33.95% except for titratable acidity and lactic acid content which increased significantly during 8 weeks storage under refrigeration. Lactobacillus viability was found to remain well above 8 log CFU/ml for four weeks. Total plate count remained within acceptable limits during the first 5 weeks and yeast and mould count was within satisfactory limits throughout the storage period of 8 weeks. Presence of coliforms was not detected during the storage of 8 weeks. Overall acceptability of probiotic guava juice was 8.56.