Volume 35, Issue 5 (September 2007)
Testing and Evaluation of Quality Changes of Treated Fresh-Cut Tropical Fruits Packaged in Thermoformed Plastic Containers
Fresh-cut fruit accounted for nearly $300 at retail in the U.S. in 2004, with projected sales ranging between $1 and $2 billion by 2008. The choice of packaging materials and the atmospheric conditions both inside and outside the package contribute significantly to the shelf-life of these products. This study evaluated quality changes such as firmness, color, total soluble solids (TSS), titratable acidity (TA), sensory quality, and microbial safety of fresh-cut mangoes, pineapples, melons, and mixes of these fruits. Chemical treatments to reduce browning, firmness loss, and decay for these fruits were also investigated. The most effective treatments for fresh-cut mangoes, pineapples, and melons were 0.1 M ascorbic acid, 0.2 M ascorbic acid, and 0.2 M ascorbic acid plus 0.2 M calcium chloride, respectively. These fresh-cut tropical fruits were packaged in three semi-rigid containers made of polyethylene terephthalate (PET), oriented polystyrene (OPS), and oriented poly(lactide) (OPLA). Gas composition in the package headspace and the time to reach steady-state conditions were observed to vary among fresh-cut packaging systems and affected their quality and shelf-life. The effects of package permeability, with regards to O2 and CO2, on quality and shelf-life of the fresh-cut products are discussed in this paper. Extended shelf-life was observed in fresh-cut mangoes, pineapples, and mixes packaged in PET due to reduced O2 and elevated CO2 atmosphere. Modified atmosphere of 6% O2 and 14% CO2 achieved in PET extended the shelf-life of fresh-cut pineapples from 6 to 13 days. The results suggest that shelf-life of fresh-cut fruit could be extended using appropriate semi-rigid containers.