Effect of thermal pasteurization and ultraviolet treatment on the quality parameters of not-from-concentrate apple juice from different varieties

Abstract

Consumers are increasingly seeking not-from-concentrate (NFC) juice as a convenient, less expensive alternative to fresh juice. This study evaluated the effect of thermal pasteurization (TP) and ultraviolet (UV) treatment of NFC apple juice on microbial growth and changes in the quality parameters. Both TP and UV decreased the total number of bacteria, mould and yeast and achieved the requirement of commercial sterilization in the NFC juice. The soluble solids, total sugars and phenolics in the juice were not significantly affected by both UV and TP. The shelf life of NFC samples treated with UV and TP was extended for 3 and 5 weeks longer than freshly squeezed juices, respectively. However, the samples treated with UV could effectively avoid the increasing of turbidity and improve quality characteristics. UV is a suitable alternative to TP during processing, because UV effectively retains fresh-like properties.

Keywords

• nfc apple juice
• thermal pasteurization
• ultraviolet
• shelf life
• the physical and chemical properties