Keywords: fresh produce, leaf water status, weight loss, colour retention, bunched spinach leaves, postharvest quality, quality indices, packaging, low density bags, polyethylene bags, polypropylene bags, colour loss
Evolution of quality indices of fresh bunched spinach stored using low density polyethylene and polypropylene bags
Packaging technology constitutes an available method for reducing postharvest deteriorative processes on fresh products. The purpose of this work was to evaluate leaf water status, weight loss and colour retention of bunched spinach leaves packaged in low density polyethylene (LDPE) and polypropylene (OPP) bags, stored at 2°C for 25 days. Water status was determined through relative water content (RWC), the free:total water ratio (FW/TW) and bound water (BW); colour was evaluated colorimetrically as hue angle. Gaseous concentrations reached in OPP bags (11% O
2, 3%-5% CO
2) were within those considered beneficial for spinach. Weight loss was higher in LDPE than OPP bags. RWC was lower in LDPE than in OPP bags. RWC decreased after day 18. Increases occurred in BW and decreases occurred in the FW/TW, indicating possible water movement within the leaf. Hue angle diminished after seven days of storage, indicating loss of green colour. Better physical and physiological properties were observed in spinach packaged in OPP bags.