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

Abstract

Borage (Borago officinalis L.) is a wild vegetable appreciated as a folk medicine and for culinary preparations. The introduction of borage as a specialized cultivation would allow for the diversification of vegetable crops and would widen the offerings of raw and minimally processed leafy vegetables. Thus, the aim of the research was to evaluate the quality and shelf-life of fresh-cut borage stored at different temperatures. Borage plants were grown during the autumn–winter season and immediately minimally processed after harvest. Fresh-cut borage leaves packed in sealed bags were stored at 2 or 6 °C for 21 d. Weight loss, total soluble solids (TSS), titratable acidity (TA), ascorbic acid, nitrates, leaf color characteristics and overall quality were determined through the storage period. Borage plants were deemed suitable for minimal processing. Storage temperature significantly influenced the rate of quality loss. Borage leaves had an initial nitrate content of 329.3 mg kg−1 FW that was not affected by temperature or storage. TSS and TA were higher in leaves stored at 6 °C. TSS, TA and ascorbic acid content increased during storage. Minimally processed borage leaves stored at 2 °C had lower weight loss and leaf color modifications during storage and a longer shelf life than those stored at 6 °C, so were still marketable after 21 d of storage.

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

“…This parameter increased significantly during storage in all the tested samples up to 258.4 mg 100 g −1 fw of citric acid equivalent on average after 14 d at 4 °C. Similar results has been found for minimallyprocessed borage, cauliflower, red chicory, and escarole that showed increases of titratable acidity during cold storage [19,[35][36][37]80].…”

“…Minimally processed borage leaves showed a good color stability during cold storage. In fact, no significant changes in color parameters was recorded during 14 d of storage except for the increase of lightness (Figure 6a) and the reduction of hue angle on day 14 in the leaves of accession H grown at the lowest plant density (Figure 6b) as also found for minimally-processed borage stored at 6 • C [19]. Even though the color variations were small, the perceived visual quality showed a reduction of the scores during storage.…”

“…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. The color variability of borage leaves was mainly due to the difference between the tested borage accessions as already reported for chlorophyll content; accession H had leaves more yellowish (higher a* values) and greenish (higher b* values), resulting in a more vivid color (chroma) than accession D4 (Table 4).…”

“…Ascorbic acid is considered a very labile compound that can quickly degrade during storage at ambient temperature. Nonetheless, cold storage of vegetables packed in sealed bags showed to strongly slow down its deterioration or even increase its content as found for borage, broccoli, green asparagus, carrots, Swiss chard, and rocket [19,26,49,53,[85][86][87]. These increases have been attributed to physicochemical changes or to unidentified enzymes that regenerate ascorbic acid [86].…”

Influence of Ecklonia maxima Extracts on Growth, Yield, and Postharvest Quality of Hydroponic Leaf Lettuce

“…The perceived quality of leafy vegetables is greatly determined by appearance and color as they affect food choice and satisfactoriness and could also impact the consumer's perception of sensory quality. Color characteristics and the way they change during storage can be influenced by preharvest [12,15,48,96,97] or postharvest [98][99][100][101][102] factors. Leafy vegetable color can be altered by browning and yellowing (chlorophyll degradation) phenomena that could negatively affect marketability [48].…”