Evaluation of microbiological and physico‐chemical parameters of retail ready‐to‐eat mono‐varietal salads

Abstract

An integrated microbiological and physico‐chemical approach was applied to evaluate the decay of mono‐varietal ready‐to‐eat escarole (Cichorium endivia var. latifolium) and red chicory (Cichorium intybus L. var. foliosum Hegi) during refrigeration. Total mesophilic microorganisms, including pseudomonads, and total psychrotrophic microorganisms were detected at high numbers in all samples just after packaging and at the expiry date. The dominant microbial populations analyzed by classical culture‐dependent methods belonged to Pseudomonas and yeasts. Illumina sequencing identified Janthinobacterium lividum and Pseudomonas veronii as main species. Regarding the physico‐chemical quality between the beginning and at the end of the expiry date, the main differences were found for weight loss, higher for escarole, and titratable acidity and lightness, higher for red chicory. This work showed how the microbiological and physico‐chemical shelf life parameters changed during storage for escarole and red chicory, even though the cold chain was strictly applied and kept under control. Practical applications The evaluation of the microbiological, chemical, and physical qualities of mono‐varietal escarole and red chicy during refrigeration indicated how the viable levels of bacteria and yeasts, microbial composition, weight loss, titratable acidity, ascbic acid content, lightness, yellowness, and redness as well as visual quality changed over time. These findings are useful to understand the change of quality parameters of some of the most common vegetable ingredients of mixed salads.

Suitability of Borago officinalis for Minimal Processing as Fresh-Cut Produce

“…Minimally processed borage leaves stored at 2 °C had an OQ score higher than four after 14 d and were still marketable after 21 d of cold storage. Minimally processed borage leaves exhibited a shelf life longer than the expiration date usually adopted for fresh-cut vegetables (7-10 d), especially when stored continuously at a low temperature, as was also found for other minimally processed leafy vegetables packed in plastic bags [40,43,[47][48].…”

Influence of Preharvest Gibberellic Acid Treatments on Postharvest Quality of Minimally Processed Leaf Lettuce and Rocket

“…Lers et al [74] found that preharvest GA 3 treatments were effective in reducing the respiration rate of parsley leaves stored for 8 d at 25 • C, while in our experiment we did not find a modification of metabolites (soluble sugars or total acidity) that could have confirmed the effect of GA 3 on respiration rate. This was probably due to the low temperature and to the atmosphere inside the sealed bags that was effective in slowing the respiration process [65,75].…”

Effect of Agronomic Practices on Yield and Quality of Borage at Harvest and During Storage as Minimally-Processed Produce

“…• Brix at day 0 and remained almost constant until the end of cold storage (5.5 • Brix on average at day 14) ( Table 3). As reported by others authors for various leafy vegetables [26,[35][36][37][38][39], minimally-processed vegetables packed in sealed plastic bags characterized by low permeability to water vapor do not suffer dehydration due to the very high relative humidity inside the sealed packages (near to 100%). Moreover, fresh-cut leafy vegetables cold stored in sealed plastic films usually have a low respiration rate [36][37][38], as confirmed by the small variation of TSS recorded for the borage samples irrespective of accession and plant density ( Table 3).…”

“…Total soluble solids were on average 5.9 °Brix at day 0 and remained almost constant until the end of cold storage (5.5 °Brix on average at day 14) ( Table 3). As reported by others authors for various leafy vegetables [26,[35][36][37][38][39], minimally-processed vegetables packed in sealed plastic bags characterized by low permeability to water vapor do not suffer dehydration due to the very high Consumer's perception of vegetable quality is mainly influenced by their color and appearance; thus, color modifications and overall appearance are the primary parameters for the quality evaluation of vegetables, especially those minimally-processed [44,48]. These modifications may occur due to both pre-harvest [48][49][50][51][52] or post-harvest [17,19,[35][36][37]53,54] factors.…”