Aseptically packaged UHPH-treated apple juice: Safety and quality parameters during storage

Abstract

Ultra-high pressure homogenization (UHPH) at 300MPa and 4°C inlet temperature were used to preserve apple juice, and shelf-life evaluation of aseptically packaged juice was investigated. After processing Tetra Brik containers were stored at temperatures of 4, 10, 20 and 30°C during 60days. In this article, the effect of processing on the spoilage inactivation was evaluated after processing and during the storage trial. Non-germinated and germinated spores were found in the UHPH-treated juice, being an inactive population during storage. Patulin content was also not modified by UHPH processing, but a significant decrease was observed during storage at 30°C (P<0.05). Polyphenoloxidase (PPO) and pectinmethylesterase (PME) activity was not found after UHPH-processing and during storage.A kinetic study of post-processing quality loss was conducted. Vitamin C, chlorogenic acid, total polyphenols and color change were measured during storage study and were used to model the UHPH-treated apple juice shelf-life. Loss of vitamin C was correlated with the hydroxymethylfurfural (HMF) accumulation (0.59, P<0.05). A limiting quality parameter was polyphenolic content. UHPH-treated apple juice stored at 4°C was found to show a shelf-life for about 21months by preserving the color characteristics of the juice with low HMF accumulation. From 15°C changes in quality parameters were more evident.