Cutting shape, film and storage temperature affect the shelf-life of fresh-cut pumpkin

Pumpkins (Cucurbita spp. L.) can be used in large scale in the fresh-cut sector, due to their increasing consumption in many countries. The processing operations of pumpkins include peeling, portioning and packaging. A research has been conducted in order to study how the cutting shape (sliced or 2-cm diced), packaging permeance to O-2 (P1=1990; P2=750; P3=560 cm(3) m(-2) d(-1) bar(-1)) and storage temperature (4 or 8 degrees C) can affect the physiology and quality of fresh-cut 'Cinderella' pumpkin (Cucurbita maxima Duchesne) stored for an 8-day shelf-life period (d8). The gas composition (O-2; CO2), pigments, total phenolic content (TPC), antioxidant power (AP) and vitamin C (Vit. C) content were analyzed at processing and during the shelf-life period (d5 and d8). Fresh weight loss was recorded daily. During the shelf-life, the O-2 and CO2 contents were found to only depend on the cutting shape and temperature. The O-2 in the headspace decreased more significantly at 8 degrees C than at 4 degrees C, and more in the bags containing pumpkin dices than in the bags containing pumpkin slices. However, the O-2 levels on d8 were similar and not statistically different in both bags containing dices and slices and in the bags stored either at 4 or at 8 degrees C, respectively. The CO2 in the headspace increased more in the bags stored at 8 degrees C than in the bags stored at 4 degrees C, and more in the bags containing pumpkin dices than in the bags containing pumpkin slices. Fresh weight was affected by the film during the shelf-life, regardless of the storage temperature, with an increasing weight loss as the O-2 permeance of the films decreased; P3 showed a more significant weight loss than the higher permeance films. A significant interaction between film and shape was observed from d6 to d8: the weight loss of the pumpkin slices continued to increase as the permeance decreased, whereas it decreased as the permeance increased. The Chlorophyll b, vitamin C and carotenoid contents were affected by the film x shape interaction on d5. All the variables of the pumpkin dices decreased as the O-2 permeance increased, while they increased in the pumpkin slices packaged with the intermediate O-2 permeance film. AP was affected by shape x O-2 permenace on d8. Chlorophyll was not affected by the treatments. TPC and AP were only affected by temperature x shape on d8, while the vitamin C and carotenoid values were affected by the temperature, with higher values at 4 degrees C of storage than at 8 degrees C.