Conservation of crisp lettuce in different post-harvest storage conditions

Abstract

The objective of this work was to evaluate the post-harvest quality and the final storage time of the hydroponic crisp lettuce 'Brida', conditioned in different types of plastic packaging and environments. The statistical design was a completely randomized 3x2 factorial design, with 3 types of packages (control (without plastic packaging), perforated plastic packaging and closed plastic packaging) and 2 types of environments refrigerated (± 5 °C) and non-refrigerated (± 23 °C). Fresh leaf weight loss, relative SPAD content, total soluble solids content (TSS), pH, total titratable acidity (TTA), chlorophyll a and b, carotenoids and final storage time were measured. There was a decrease in the parameters of fresh mass, acidity, total soluble solids, and relative content of SPAD chlorophyll in refrigerated lettuce compared to uncooled. The use of packages also influenced post-harvest quality and closed packs resulted in lower values. It is concluded that the post-harvest quality of lettuce is better when they are refrigerated and packed in sealed packages.

Development of chitosan-based biodegradable films enriched with thyme essential oil and additives for potential applications in packaging of fresh collard greens

“…Physiological weight losses (PWL) were determined by comparing weight of samples before and after the storage period. The results were represented as weight loss percentage with regard to the initial weight 25 . where W in is the weight of the first day and W fin the weight of final day.…”

“…Titratable acidity of collard greens was determined according to the method of Schvambach et al 25 . One gram of sample was macerated with 75 mL of distilled water using phenolphthalein indicator and titrated with 0.1 M NaOH.…”

Yield and nutritional quality of soil‐cultivated crisphead lettuce (Lactuca sativa L. var. capitata) and corn salad (Valerianella spp.) harvested at different growing periods

“…Among these, crisphead lettuce (var. capitata L. nidus jäggeri Helm), which includes Batavia, Iceberg, and Eissalat, is one of the most popular types in Europe, the USA, and Brazil (Kim et al, 2016 ; Noumedem et al, 2017 ; Schvambach et al, 2020 ). Crisphead lettuce is traditionally soil cultivated and sold as whole‐head salad that forms a dense head/rosette with leaves branching from a single stalk, although the supply of hydroponically produced ready‐to‐eat baby leaf lettuce is increasing (Pinotti et al, 2020 ).…”