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United States Department of Agriculture

Agricultural Research Service

Title: Osmotic Dehydration of Apple Slices Using a Sucrose/calcium Chloride Combination to Control Spoilage Caused by Botrytis Cinerea, Colletotrichum Acutatum and Penicillium Expansum

item Chardonnet, Catherine - UNIVERSITY OF TENNESSEE
item Conway, William
item Draughon, Frances - UNIVERSITY OF TENNESSEE

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 21, 2001
Publication Date: N/A

Interpretive Summary: There is an increased demand for processed fruits which maintain quality similar to fresh fruits. Several techniques have been developed to partially remove water from fruits and vegetables in order to increase shelf-life of produce, reduce aroma losses in dried and semi-dried foodstuffs , and retain maximum quality in the final product. The advantage of dried food over fresh food is that it can be stored and transported at a relatively low cost. Osmotic dehydration using concentrated sucrose solutions has been used in osmo-dehydration of raw apple material, but fungal decay can be a problem. We found that apple slice spoilage can be significantly reduced by combining 2% calcium chloride with the 20-30% sucrose solutions which may be used for the dehydration process. The apple processing industry may find the combination of calcium chloride and sucrose to be an effective method of reducing losses in the osmo-dehydrated product.

Technical Abstract: The efficacy of sucrose combined with calcium chloride during osmotic dehydration (OD) was tested for the control of Botrytis cinerea, Colletotrichum acutatum and Penicillium expansum growth on lightly processed apple slices. The mass ratio of the slices did not vary when fruit pieces were processed for 1 h at 25 degrees C in a solution containing sucrose only. The addition of calcium chloride to the sucrose solutions decreased the mass ratio of the slices by 8% with 65% sucrose/2% calcium chloride. Calcium uptake by slices was significantly increased when processed in calcium chloride solutions (with 0% sucrose) and the highest calcium content was observed when processed in 8% calcium chloride, reaching 40 times that of the control processed in water. Calcium uptake by slices during OD was inversely proportional to the sucrose concentration of the solutions. Slices processed in sucrose solution only showed a higher susceptibility to spoilage caused by all three pathogens compared to the control. A significant twofold increase in decay area caused by B. cinerea was observed when slices were processed in 50% sucrose/0% calcium chloride C. acutatum showed a significant 50% increase in decay area when slices were processed in 20% sucrose/0% calcium chloride. Slices processed in 50% sucrose/0% calcium chloride showed a significant 60% increase in decay caused by P. expansum. The most effective combination in reducing apple slice spoilage caused by all three pathogens was 20-30% sucrose combined with 2% calcium chloride.

Last Modified: 4/22/2015
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