Effect of UV-LED irradiation processing on pectolytic activity and quality in tomato (Solanum lycopersicum) juice

Abstract

The aim of this research was to analyze pectolytic activities (pectinmethylesterase “PME” and polygalacturonase “PG”) and physical qualities in tomato juice treated by UV-LED, Hot Break (HB), and Cold Break (CB) processing. Tomato juice treated by UV-LED (117 mJ/cm2) obtained a residual PME activity similar to that of CB, and tomato juice treated by UV-LED (351 mJ / cm2) had a residual PME activity 28.3% lower than HB (p < 0.05). The effect of UV-LED on PG activity was similar to HB and 49% lower than CB (p < 0.05). Furthermore, UV-LED processing caused a decrease in pH and total acidity and a significant increase in total lycopene content. Antioxidant activity and viscosity for UV-LED processing were similar to CB, total polyphenol content and °Brix were similar to HB (p > 0.05). Therefore, this study provides a promising application of UV-LED technology for controlling enzymatic activity in tomato juice, and an alternative to heat treatment. Industrial relevanceNowadays, the tomato industry uses heat treatments to inactivate pectolytic enzymes. UV-LED technology could have an industrial appreciation, as it was efficient in decrease the activity of these enzymes, in addition, preserved and increased some bioactive compounds. Therfore, it is proposed as an efficient method for processing fruit and vegetable juices. Nevertheless, further studies are needed to clarify the effect of this technology on pectolytic enzymes and quality parameters in liquid fruit and vegetable foods.