|YAN, RUIXIANG - Tianjin University Of Science And Technology|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2020
Publication Date: 9/10/2020
Citation: Yan, R., Gurtler, J., Mattheis, J.P., Fan, X. 2020. Effect of Trichrome Removal and UV-C on Populations of E. coli O157:H7 and Quality of Peach Fruit. HortScience. 1-6. https://doi.org/10.21273/HORTSCI15231-20.
Interpretive Summary: Commercially, peaches are often wet-brushed to remove the hair-like fuzz from the surface of the fruit for consumer appeal. Earlier studies have demonstrated that ultraviolent C (UV-C) is able to reduce human pathogens on the surface of various fruits. However, it is unclear whether the removal of the fuzz contributes to UV efficacy and quality of peach fruit. The study was conducted to evaluate the effect of fuzz removal on the efficacy of UV-C in inactivating E. coli O157:H7 on peach fruit, and quality of peach fruit as affected by fuzz removal and UV-C. Peaches with and without fuzz removal were treated with different doses of UV-C and stored at 20 degree C for 7 days. Results showed that fuzz removal had marginal effects on the efficacy of UV-C, and UV-C did not negatively impact the quality of peaches. The information is of value for fruit packinghouses to implement UV-C as a surface decontamination technology
Technical Abstract: The objective of the study was to evaluate the effect of trichome (fuzz) removal on the efficacy of UV-C in inactivating E. coli O157:H7 on peach fruit, and quality of peach fruit as affected by fuzz removal and UV-C. Peach (cultivar PF25) fruit, with and without fuzz removal, were inoculated with a 5-strain cocktail of E. coli O157:H7 and treated with UV-C at doses of 0, 221 and 442 mJ/cm2. Fuzz was rubbed off using damped cloths. Survival of E. coli populations were determined at day 1, 4 and 7 at 20°C. To study fruit quality, non-inoculated fruit with and without fuzz removal were treated with UV-C at the same doses. Results demonstrated that UV-C at 442 mJ/cm2 reduced the population of E. coli by 1.2-1.4 log CFU/fruit on peach with fuzz, and 0.9-1.1 log CFU/fruit on fruit without fuzz 1 day after UV-C treatment. However, E. coli populations of all samples were similar with additional storage time, resulting in no significant difference among the treatments after 7 days of storage at 20°C. UV-C at doses up to 442 mJ/cm2 did not have any significant effect on the surface color of peaches during 7 day storage, although fruit with fuzz removal increased L*, hue and chroma values. In addition, fuzz removal promoted the loss of firmness during storage. Furthermore, UV-C at 442 mJ/cm2 increased antioxidant capacity of peach skin with fuzz. Overall, our results suggested that fuzz removal had marginal effects on the efficacy of UV-C, and UV-C did not negatively affect the quality of peaches.