Effects of UV-C light, ultrasonic and microwave treatments on banana puree during refrigerated storage

FRANCO RODRIGO; ROMPATO KARINA; OJEDA GONZALO; SGROPPO, SONIA C

Congreso; III Congreso Argentino de Biología y Tecnología Postcosecha; 2021

The colour change in banana puree due to enzymatic browning is evidenced by the development of brown colour and an increase in the activity of oxidant enzymes, influencing nutritional quality. Non-conventional technologies such as UV-C radiation, ultrasound and microwaves are being studied and developed to obtain a better sensory quality in the final product, including microbial safety, and could be an effective treatment for minimally processed bananas. They have been applied in minimally processed fruits with enzymatic profiles similar to those found in bananas.The objective of this work was to evaluate the effects of UV-C light, ultrasound and microwaves application to banana puree as control method of enzymatic browning during the refrigerated storage.Minimally processed purees were subjected to UV-C light (1.97 kJ/m2), ultrasound (40 kHz for 10 min) and microwave heating (800 W for 25 s). Color parameters L*, a*, b*, chroma, hue and Browning Index (BI) by computer vision system (CVS), the enzymatic activity (PPO and POD) and total phenolic compounds and antioxidant capacity (AOC) by three methods were monitored throughout storage at 4 ºC. Besides microbiological load was also determined. A significant (P < 0.05) reduction in the enzymatic activity of PPO and BI were observed in purees treated with ultrasound and microwave, contributing to the stability of color during refrigerated storage. However, the UV‐C treatment was not effective in browning control, but was effective to maintain microbial quality, being microbial counts 1.48 ± 0.01 log CFU/g after 20 days of storage. PPO activity and the most sensible parameters of color for banana puree found, b*, chroma and BI, showed an inverse correlation with antioxidant capacity and phenolic compounds.The information provided in this research indicates that emerging technologies are an important tool for the food industry to maintain the quality of foods, especially in minimally processed such as banana puree. Due to the oxidative enzymes present in this fruit, enzymatic browning may occur could being a significant economic loss in the industry and therefore these enzymes must be inhibited. Results indicated that microwave and ultrasonic treatments can significantly retard enzymatic browning and aids in preserving the nutritional quality during storage at 4 °C. In addition, UV-C light proved the most effective method to decrease the microbial load in banana puree.