ARS | Publication request: Underwater processing with and without added calcium influences shelf life quality of fresh-cut cantaloupe melon.

Submitted to: Journal of Food Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 31, 2009
Publication Date: June 1, 2010
Citation: Lamikanra, O., Bett Garber, K.L., Watson, M.A., Ingram, D.A. 2010. Underwater processing with and without added calcium influences shelf life quality of fresh-cut cantaloupe melon. Journal of Food Quality. 33:246-261.

Interpretive Summary: Wounding of produce, such as in fresh-cut processing, rapidly sends electrical, hormonal,and chemical signals through the cells in the entire product. Response to the signals received, contributes to the reduced shelf life of cut products. One of its primary signals of wounding is loss of turgor (hydraulic pressure) caused by the sudden movement of fluids when cells are ruptured. In this study, we have investigated the effect of reducing this surge by submerging the fruit underwater during cutting. Water could serve as a barrier to fluid movement, potentially reduce the severity stress signals, and consequently, extend product shelf life. Results indicate that microbial growth was lower in underwater processed fruit after 1 day storage at 4 oC, but was not significantly different after 7 days. Dissolved calcium in treatment water reduced microbial growth in cut fruit over the storage period of 14 days relative to aerobically processed fruit. Calcium also induced a hypersensitive defense response by the production of peroxidase (antioxidant) enzymes. Human sensory evaluation indicated decreased moisture release and translucency (the water-soaked appearance) in underwater processed fruit during storage. Results indicate potential improvement of shelf life of cut cantaloupe melon by underwater processing. This study is useful for the development of processing methods to improve sensory quality and shelf life of fresh-cut fruits.

Technical Abstract: The effect of processing cantaloupe melon while submerged under water on the fresh-cut fruit quality was determined. Total plate, coliform, yeast, and mold counts were lower in underwater processed fruit after 1 day storage at 4 oC, but were not significantly different after 7 days. Dissolved calcium in the treatment water reduced microbial growth in cut fruit over the storage period of 14 days. Sensory evaluation indicated decreased moisture release and translucency in underwater processed fruit. Peroxidase activity was elevated in underwater processed fruit when calcium was dissolved in treatment water. Results indicate an increased defense response as a result of underwater processing that is enhanced by the presence of calcium ions in the treatment fluid.