Postharvest shelf life extension of minimally processed kale at ambient and refrigerated storage by use of modified atmosphere.

Kale is becoming an important vegetable worldwide, mainly due to its nutritional properties. Kale leaves can be marketed whole, although minimal processing is also in demand. In this article, it was analyzed the effect of packaging in a modified atmosphere of fresh-cut kale leaves stored at 20 °C and 4 °C. Kale leaves were cut into 4 × 4 cm strips and stored in low-density polyethylene bags. Samples processed in the same way but stored in PVC were used as controls. Leaves kept in a modified atmosphere showed a delay in color change with Hue values from about 130 to 120 under PMA against 130 to 100 in control group (CTR) leaves. Chlorophyll degradation was also delayed in both storage temperatures. Samples stored under PMA showed about two times the levels of total chlorophylls with respect to CTR samples at the end of the storage. No changes in total sugar content were detected during storage and no differences were detected between control and modified atmospheres stored samples. Samples maintained in a modified atmosphere showed a lower decrement in soluble proteins and a lower rate of RUBISCO degradation at both temperatures. The relation of RUBISCO content PMA/CTR ranged from 1 to about 3 toward the end of storage No changes in phenols content were found when comparing control and treated samples. However, flavonoid and the antioxidant contents increased in samples stored in modified atmospheres with respect to their controls. We demonstrated that storage in modified atmospheres could be an adequate and simple methodology to extend postharvest life of this minimally processed product at both ambient and refrigerated storage.

Bio-Packaging Material Impact on Blueberries Quality Attributes under Transport and Marketing Conditions.

Blueberries are highly appreciated for their high antioxidant content but are also particularly susceptible to fungal deterioration. In this work, corn starch and chitosan, byproducts of the fishing industry, as well as active compounds obtained from citrus processing waste were used to obtain active biodegradable film packaging. Blueberries were packed in corn starch-chitosan (CS:CH) films and in active films containing lemon essential oil (LEO) or grapefruit seed extract (GSE). The effects of film packaging on the quality parameters of berries and the fungal incidence of disease during storage were studied and compared to benchmark materials. A conservation assay simulating transport and commercialization conditions was conducted. Blueberries packed in CS:CH films showed antioxidant capacity values closer to those packed in commercial PET containers (Clamshells), preserving 84.8% of the initial antioxidants content. Fruit packed in LEO films exhibited the greatest weight loss and rot incidence, and poor surface color. CS:CH and GSE films controlled the fruit respiration rate and weight loss, therefore they are materials with adequate barrier properties for blueberries conservation. Bags formulated with GSE showed adequate barrier properties to maintain fruit quality attributes without the incidence of rottenness, being an interesting option for blueberries exportation.