Leila Mendes Pereira

Kinetic Aspects, Texture, and Color Evaluation of Some Tropical Fruits during Osmotic Dehydration

ABSTRACT Osmotic dehydration of some tropical fruits like guava, melon, and papaya using sucrose and maltose solutions is presented in this article. The influence of sugar type and concentration, process temperature, and calcium salt addition on osmotic solution was investigated. Water loss and sugar gain up to 6 h of processing were evaluated and the effect of osmotic dehydration on fruit quality parameters like color and texture was analyzed. All studied variables affected the osmotic process kinetics, while for quality parameters the influence of sugar type or solution concentration and temperature was dependent on fruit and process conditions.

Vida útil de fatias de manga armazenadas em embalagem com atmosfera modificada passiva

Fresh and osmodehydrated mango slices were packaged in expanded polystyrene trays covered with low density polyethylene films (PEBD) and stored at 5 °C aiming at verifying the effect of osmotic dehydration process and modified atmosphere packaging on the fruit shelf life. Fresh mango slices packaged under atmospheric conditions were used as control. The slices were evaluated periodically with respect to physicochemichal and microbiological characteristics, internal atmosphere composition of the packages, weight reduction, and sensory acceptance. The osmotic dehydration process and the modified atmosphere packaging had a positive influence on the preservation of the sensory characteristics and microbiological quality of the mango slices. Fresh mango slices stored under atmospheric conditions (FR AR) and modified atmosphere packaging (FR MAP) had a shelf life of only 8 and 14 days, respectively, which was mainly limited by its sensory acceptance and microbial spoilage. On the other hand, the mango osmodehydrated slices packaged under modified atmosphere (OD MAP) presented shelf life of 18 days showing good sensory acceptance throughout the storage period.

Calcium lactate effect on the shelf life of osmotically dehydrated guavas.

The effect of calcium lactate on osmodehydrated guavas in sucrose and maltose solutions was monitored during storage under passive modified atmosphere for 24 d at 5 °C. Sample texture and color characteristics, microbial spoilage, sensory acceptance, structural changes, and gas composition inside the packages were periodically evaluated. Calcium lactate inhibited microbial growth on guavas, with yeast and mold counts in the order of 10(2) CFU/g throughout storage. The calcium salt reduced respiration rate of guava products, showing O(2) and CO(2) concentrations around 18% and 3% inside the packages. A firming effect on fruit texture, with up to 5 and 2 times higher stress and strain at failure values and tissue structure preservation could also be attributed to calcium lactate use. However, fruits treated with calcium lactate, osmodehydrated in maltose and sucrose solutions, showed sensory acceptance scores below the acceptability limit (4.5) after 13 and 17 d of storage, respectively.