Microbiological quality in convenient ready-to-eat vegetables during shelf life

Abstract

Minimally processed vegetables and fruits are the main ingredients of ready-to-eat salads, often sold in convenient packaging. The increased consumption of ready-to-eat products is a result of a fast lifestyle and awareness on their nutritional attributes. Additionally, the processing technology is well documented. This study aimed to determine the microbiological quality of shredded Iceberg lettuce (Lactuca sativa var. capitata), sliced tomato (Solanum lycopersicum) and diced mango (Mangifera indica L.). From each batch, five random units were selected, one of which was analyzed on the day of production (initial sample—IS) and the other four after their shelf life (final sample—FS). The samples were tested for aerobic colony count (ACC) 30 °C, Enterobacteriaceae, Enterococcus spp., Pseudomonas spp., Aeromonas hydrophila, molds and yeasts. The results showed that ACC of diced mango and shredded lettuce had a similar median of 6.20 and 6.08 log g−1, respectively, and sliced tomato had the lowest one (5.40 log g−1). The median value found for Enterobacteriaceae was 3.47 log g−1. The FS for Enterococcus of diced mango and shredded lettuce had a similar median (1.00 log g−1) and sliced tomato had the highest (2.54 log g−1). Both IS and FS had higher unsatisfactory rate for Aeromonas hydrophila. All samples revealed acceptable rate for molds and yeasts. This study found high microbial loads in ready to eat vegetables. Data showed that this type of product should be subject to a more stringent quality control, so that the consumers could be provided not only with easy to consume products but also with microbiological quality products during their shelf life.