Abstract
The effects of postharvest short-term irradiation with near infrared (NIR, 850 nm at 100 mmol・m−2・s−1 for 5 min) on weight loss, stomata apertures, and appearance quality were investigated in three leaf vegetables. Leaf lettuce, spinach, and spinach mustard (Komatsuna) at commercial maturity were exposed to NIR for 5 min once before storage or every day, packaged in perforated or non-perforated polyethylene bags, and then stored at 10°C under dark conditions. In all three leaf vegetables under both storage conditions, packaged in perforated and non-perforated polyethylene bags, weight loss rates and stomata aperture after 3 days of storage were reduced in NIR-exposed crops, compared with non-treated controls, resulting in a better appearance quality. The beneficial effects were more distinct in everyday treated than in single treated crops. When leaf vegetables packaged in perforated polyethylene bags were treated with NIR and stored at 10°C under dark or light conditions, weight loss rates were reduced and the appearance quality was better under both conditions, compared with non-treated controls. The beneficial effects were more marked in everyday treated than in single treated crops. The greatest benefits were observed in spinach. These results suggest that postharvest short-term NIR radiation has a promising potential as an additional quality control technique during the storage and transportation of leaf vegetables.
