30B-31 |
Determination of the lower oxygen limit for aerobic respiration of fresh-cut produce |
J. G. LOAIZA and L. Cisneros-Zevallos. Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843 Packaging design targets shelf life extension of fresh produce based on quality attributes such as color, texture, flavor, nutrition and safety. This will be possible using appropriate storage temperatures and reaching appropriate gas compositions within the bags. However, it is common to miss the target due to poor temperature management causing oxygen depletion and inducing anaerobic respiration. Anaerobic respiration accelerates produce deterioration and takes place under a critical O2 level known as the lower oxygen limit (LOL). The LOL concept can be used as a safety margin in packaging design for fresh-cut produce to ensure aerobic conditions. The objective of this study was to establish a data base of LOL values for different types of fresh-cut produce of commercial importance. Different fruits and vegetables such as carrots, bell peppers, onions, celery, apples, melons, lettuce, spinach, were cut into slices, coins and sticks. The LOL was determined using closed jars and monitoring O2 depletion and CO2 production or alternatively using plastic bags with varying amounts of tissue to obtain different O2 and CO2 steady state levels. LOL was determined in a temperature range from 0 to 20°C. The LOL values ranged from ~ 0.1 to 2.5% O2 and was tissue specific. The LOL values may increase with temperature due to diffusion effects and this dependency is related to tissue density. For a temperature range of 0 to 20°C, carrot disks (1g/cm3) showed LOL values of 0.5 to 2.5%, while spinach leaves (0.5 g/cm3) had LOL values of 0.5 to 1% in the same temperature range. The LOL concept in packaging design would be important for the fresh-cut produce industry since it establishes a security margin to avoid anaerobic respiration and its detrimental effects in accelerating quality deterioration of the produce.
Session 30B, Fruit & Vegetable Products: Sensory, Product Development, Fresh-Cut, and Storage
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