Effect of citric acid and high pressure thermal processing on enzyme activity and related quality attributes of pear puree

This study investigated the effect of thermal and high pressure thermal processing with and without citric acid on the activity of oxidative enzymes and related quality attributes of pear puree. Citric acid inhibited enzymatic browning, protected polyphenolic antioxidants against oxidative degradation and resulted in 50% increase in antioxidant capacity when it was added at 2% (w/w). Acidified pear puree can possibly be used as an ingredient in products such as yoghurts, jams and baby food after either thermal or high pressure thermal processing due to its reduced oxidative enzyme activity, low pH, high antioxidant capacity and excellent color retention.