Changes in microbial quality of fruit juices, syrups, and ready-to-serve carbonated drinks produced with different processing parameters and stored in different conditions within six months

The research was carried out during 2015-2017, aimed to consider the microbial quality of juice, syrup, and ready-to-serve (RTS) carbonated beverage prepared from mandarin fruit (Nagpur cultivar). Fully ripened, mature, fresh fruits were washed and peeled, then the juice was extracted using a screw-type pulper. The syrup and ready-to-serve carbonated beverage prepared from the extracted juice. Microbial analysis of juice was carried out by using Potato Dextrose Agar (PDA) culture medium. The results revealed no microbial growth in the ready-to-serve carbonated beverage up to 60 d of storage, after that from 90 to 180 d of storage was negligible. In the syrup, up to 90 d was no detection of microbes; after that, up to 180 d of storage was negligible. In the juice samples under cold storage (S2), all the treatments were within acceptable levels for 180 d. But under room temperature (S1), eight treatments (T1, T2, T3, T4, T5, T6, T8, T9) showed microbial colonies more than acceptable level, and only one treatment (T7-S1P3B1= juice sample in the cold storage (SI) which added 350 ppm sodium benzoate as chemical preservative (P3) and packed in the glass bottle (B1) was remained safe for consumption during 180 d of storage. The microbial quality, viz. yeast and mold count were increased during 180 d of storage in the ready-to-serve carbonated beverage, syrup and juice. The microbial growth was observed within the acceptable level in all treatment combinations of ready-to-serve carbonated beverage, syrup; and juice in cold storage and T7 of juice under ambient conditions.