Effect of film packaging and storage temperature on physical and chemical changes in fresh-cut green asparagus.

The effect of two packaging materials, film 1 (PVC film manually extensible, 12 ?m thickness, O2 permeability of 22,000 cm3/m2/24 hrs/atm) and film 2 (polyolefinic film 13 ?m thickness, heat shrinkable, O2 permeability of 8,500 cm3/m2/24 hrs/atm) on changes in the oxygen, carbon dioxide and ethylene concentrations within the film packaging, weight losses, chemical parameters and textural properties of fresh-cut green asparagus (Asparagus officinalis L.) were evaluated during 3 weeks of storage at 2 or 10°C. During the first 2 days of storage in-package carbon dioxide and ethylene concentration increased progressively, while oxygen level decreased. An overall decrease in pH, sucrose and fructose content was observed while increase in titratable acidity was observed in non-packaged asparagus. A significant increase in total phenols and total soluble solids was recorded, while in film 2 at 10°C significant decrease were detected in total soluble solid. Antioxidant activity did not change in asparagus packaged at 2°C while in unpackaged and in film 1 and 2 at 10°C significantly decreased. Ascorbic acid contents decreased rapidly after storage in all samples. Weight loss increased markedly in non-packaged asparagus, in asparagus packaged with film 1 at 10°C significant differences were detected. Both packaging materials preserved rheological properties of spears whereas un-packaged asparagus lost rapidly crispness. The overall results showed that the best storage conditions to extend the shelf-life of fresh-cut green asparagus occurred by combining packaging and storage at 2°C.