engleski

Effects of UV-C light on bacterial population and phenolic content of fresh-cut potato

Minimal processing of the potato generally includes operations such as peeling and cutting, which cause tissue damage, but does not involve any heat treatment, what consequently leads to the product's great susceptibility to the microbial spoilage. Therefore, as minimally processed (fresh-cut) potatoes are very perishable, and in order to prolong its shelf life, non-thermal processes that are effective in microorganism's reduction without negative effects on the quality, are investigated. Nowadays, the application of UV-C light (electromagnetic waves that have a germicidal effect) in food technology have been studied with promising results. Hence, the aim of this study was to examine the effect of UV-C light on microbial growth, phenolic content and color of fresh-cut potatoes. Slices of peeled potatoes were exposed to different doses of UV-C radiation (2.28 kJ/m2, 3.42 kJ/m2 and 5.7 kJ/m2) with and without the rotation of slices considering the lamps position and the chamber design. The effectiveness of UV-C treatment on fresh-cut potatoes was monitored through determination of aerobic plate count, total phenolic content, and visual appearance as browning degree of treated slices after 24 hours at 10 °C. The results showed that there was a significant reduction in the aerobic plate count in irradiated slices compared to the untreated ones, even at the lowest radiation dose. The decrease was greater when slices were rotated, but the dose increase is not linear with the decrease of the aerobic plate count. The content of total phenolic in treated slices was higher than in untreated ones but without a statistical significance. The visual appearance as browning degree of treated samples stored for 24 hours at 10 °C was consistent with the results of the total phenolic content meaning that higher phenolic content was determined in slices with higher browning degree. Summarizing all obtained results, it can be concluded that radiation dose of 3.42 kJ/m2 with the slice rotation could be recommended for the pre-treatment in potato's minimal processing based on the aerobic plate count and the visual appearance of the potato’s slices.

fresh-cut potato ; UV-C irradiation ; phenolic content ; microorganisms

nije evidentirano