Effects of heat treatment on the physicochemical parameters of acerola fruit (Malpighia emarginata DC.) juice over maturity indexes

Abstract

Acerola (Malpighia emarginata DC.) is a tropical fruit characterized by its high content of ascorbic acid and other micronutrients. Since thermal processing is approached to increase the shelf existence of foods and beverages by inactivating microorganisms and enzymes, this research was to investigate the physicochemical changes of acerola fruit juice under heat treatments. On behalf of ripeness, three stages of unripe, semi-ripe, and fully ripe acerola fruits were investigated. Under the heat treatment of 80°C for 20 minutes, the unripe fruits resulted in a juice with high bioactive contents including ascorbic acid of 1609.67 (mg/100g) and total phenolic content of 1697.87 (mg/100g) but with unattractive color, aroma and taste. Meanwhile, the semi-ripe and fully ripe fruits gave the juices with slightly lower content of biological compounds, however, with better sensorial characteristics. On behalf of the effect of heating regime, the fully ripe one, with remaining vitamin C content of 1109.68 (mg/100g) upwards after the thermal treatments of 70 to 90°C for 10 to 30 minutes, revealed extensive application of acerola fruit in food processing. Kinetic degradation study showed lower retention of vitamin C content (AAC) in the juices compared to that of phenolic components (TPC). The study also confirmed the higher activation energy of TPC than that of AAC in acerola fruit. In conclusion, comprehension of the change of acerola fruit juice under thermal treatments is crucial for optimizing quality of the product during processing.