Impact of High-Power Pulsed Light on Microbial Contamination, Health Promoting Components and Shelf Life of Strawberries

Abstract

The aim of this work is to evaluate the impact of high-power pulsed light (HPPL) on the microbial control and nutritional properties of strawberries. Berries were treated with HPPL and afterwards analyzed in terms of microbial contamination, shelf life extension, antioxidant capacity, firmness, total phenolic, total anthocyanin and ascorbic acid content, and colour. Results indicate that the decontamination of strawberries by HPPL was significant compared to control. Naturally distributed mesophilic bacteria on the surface of strawberries were inactivated by 2.2 log, and inoculated Bacillus cereus and Listeria monocytogenes were inactivated by 1.5 and 1.1 log, respectively. Yeasts/microfungi distributed on the surface of strawberries were inactivated by 1 log. The shelf life of treated strawberries was extended by 2 days. The increase of temperature on the surface of fruit never exceeded 42 °C. No significantly important differences were observed in total phenolic, total anthocyanin and ascorbic acid content, and antioxidant capacity of strawberry fruits before and after pulsed light treatment. Moreover, no impact on the strawberry colour or firmness was found after HPPL treatment. In conclusion, HPPL is fast, effective, non-thermal and environmentally friendly technique which can be applied for microbial control of strawberries.

Keywords

• non-thermal decontamination
• food preservation
• pulsed light
• strawberries