Ultrafiltration of cashew apple juice using hollow fibers for shelf life extension: process optimization, flux modelling and storage study

Cashew apple juice is one of the highly nutritious and perishable fruit juice. In this study, the shelf life extension of pre-treated cashew apple juice was undertaken using a non-ther mal ultrafiltration technology. A total of 16 experiments were carried out at four different molecular weight cut-offs (5 kDa, 10 kDa, 30 kDa, and 50 kDa) and transmembrane pressures (35 kPa, 69 kPa, 103 kPa, and 138 kPa) to get the optimum process conditions. After considering the highest productivity and superior quality of the filtered juice, 30 kDa molecular weight cut-off and 138 kPa transmembrane pressure were found to be the optimum processing condition for the ultrafiltration of cashew apple juice. At the optimum condition, the ultrafiltered juice had 8.22 degrees Brix TSS, 4.36 pH, 1.16 cP viscosity, 99.88%T clarity, 1.22 NTU turbidity, 0.064 abs color intensity, 196.00 mg/100 mL ascorbic acid content, 13.49 mg tannic acid/100 mL total tannin content and 110.77 mg GAE/100 mL total polyphenol content. Further, a resistance-in-series model was developed to quantify and study the limiting flux behaviour of the ultrafiltration membrane. The developed model has a huge significance (p < 0.05) during the commercialization of the system since it derived a mathematical relationship between the process parameters and the limiting flux of the membrane. Finally, a storage study was carried out and it was observed that the ultrafiltered juice was successfully stored for 12 weeks at 4 degrees C without any chemical and heat treatment (as compared to the normal shelf life of 1-2 days). This study helps to efficiently design and scaling-up of an ultrafiltration system for the clarification and cold sterilization of cashew apple juice.

Automated summary

Cashew apple juice with high nutrition and perishable features was studied for its shelf life extension using non-thermal ultrafiltration technology. After conducting 16 experiments, it was found that ultrafiltration with a molecular weight cut-off of 30 kDa and a transmembrane pressure of 138 kPa achieved the best results in terms of productivity and quality. A resistance-in-series model was developed to analyze the limiting flux behavior of the ultrafiltration membrane. The ultrafiltered juice was successfully stored for 12 weeks at 4℃ without any chemical and heat treatment.