30B-30 |
Browning and firmness changes in fresh-cut pears |
R. SOLIVA-FORTUNY, M. Biosca-Biosca, N. Grigelmo-Miguel, and O. Martín-Belloso. Food Technology Department, University of Lleida, Av. Rovira Roure 177, Lleida, 25198, Spain The consumer’s demand for fresh-like products has prompted researchers to focus on new food preservation technologies, alternative to thermal treatments. In this regard, minimal processing has proved to be an outstanding way to obtain ready-to-eat fruit commodities. However, since these products are highly perishable, the main goal is to study their shelf-life from as many points of view as possible. In this study, color and textural parameters of minimally processed pears were assessed in order to estimate the shelf-life of this sort of goods. Pears (var. Conference) were carefully processed and cut into 1 cm edge cubes. The cubes were then dipped into a L-ascorbic acid/calcium chloride solution and packaged in plastic bags of two permeabilities using different modified atmospheres. Color was evaluated during refrigerated storage with a spectrophotocolorimeter, whereas changes in firmness were studied to determine texture losses in fresh-cut pear cubes. Results show that browning in minimally processed pears is strongly represented by lightness (L*), which decreased exponentially as a function of the different packaging and storage conditions (k=0.021-0.07 day-1). Samples preserved in plastic bags of low permeability under an initial atmosphere of 100% N2 were those that better maintained the color and firmness of fresh-cut pears. On the other hand, firmness decreased linearly throughout the storage time (k=0.0086-0.037 day-1). These changes were strongly influenced by the presence of O2 in the package headspace. The best processing conditions (a 100% N2 initial atmosphere and plastic bags of low permeability) entailed a 17% linear decrease of firmness during storage. These results suggest that, from the point of view of browning and firmness changes, a proper combination of preservation factors may extend the shelf-life of fresh-cut pears beyond two months under refrigerated storage. Zero and first order kinetic models can describe with enough accuracy changes in those parameters during storage.
Session 30B, Fruit & Vegetable Products: Sensory, Product Development, Fresh-Cut, and Storage
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