217: Potential UV-Light Application for the Safety Assurance of a Passion Fruit Beverage: Treatment Impact on Patulin Content and Physicochemical and Microbiological Attributes

Introduction

Consumers’ preference towards fresher and healthy foods has prompted the adoption of nonthermal processing technologies, including UV light. Additionally, tropical fruits consumption, such as passion fruit, has internationally emerged. However, the UV suitability for the safety assurance of nontraditional tropical beverages is still unknown. Thus, this study analyzed the application of UV light for the safety assurance, in regards microbial inactivation and patulin reduction, of a passion fruit beverage. The effect of the treatment on selected physicochemical and microbiological quality indicators, in comparison with a traditional thermal treatment, was also assessed.

Methods

A passion fruit beverage was inoculated with E. coli ATCC 25922 (7 logs CFU/g) and UV treated with a CiderSure 3500 UV light processing unit at a constant UV dose of 14 mJ/cm2 at 254 nm. E. coli was enumerated, before and after treatment, using the pour-plate technique with Tripticase Soy Agar incubated at 35°C for 24 h. The beverage was also contaminated with 100 µg/kg of patulin and the mycotoxin content was determined following a HPLC protocol after applying eight accumulative UV doses between 14.2 mJ/cm² and 113.6 mJ/cm². The effect of UV (14 mJ/cm2) against a thermal treatment (68°C for 15 s) on the beverage pH, soluble solids content, titratable acidity, colorimetric parameters (L*, a*, b*) and browning index, absorption coefficient and vitamin C concentration besides molds and yeasts and total plate counts was also determined. All trials were performed in triplicate and data were statistically analyzed.

Results

A reduction of 5.91 ± 0.27 log UFC/mL of E. coli was achieved ensuring the beverage microbial safety, but the UV dose did not significantly reduce (p > 0.05) the patulin concentration. The thermal treatment applied was significantly better (p < 0.05) against molds and yeast counts yet no significant differences (p > 0.05) among both treatments were found for the physicochemical attributes tested and the beverage total plate count.

Significance

This study provides baseline information for the application of UV to ensure the microbial safety and extend the shelf life of a passion fruit beverage. However, despite the technology ensures the beverage microbial safety, the findings suggest that UV light does not represent a promising alternative for patulin mitigation in the beverage evaluated.

Authors: Dirce Bonilla, María Viñas, Oscar Acosta, Jessie Usaga