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ARS Home » Pacific West Area » Wenatchee, Washington » Physiology and Pathology of Tree Fruits Research » Research » Publications at this Location » Publication #147292
Title: INFLUENCES OF FLOAT MATERIALS ON THE QUALITY OF 'ANJOU' PEARS AFTER REGULAR AND CONTROLLED ATMOSPHERE STORAGE

Author
item Drake, Stephen
item ELFVING, DON - WSU, PULLMAN, WA
item SANDERSON, P - WA TREE FRUIT RES. COM.

Submitted to: Journal of Food Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2004
Publication Date: 5/1/2004
Citation: Drake, S.R., Elfving, D., Sanderson, P.G. 2004. Influences of float materials on the quality of 'Anjou' pears after regular and controlled atmosphere storage. Journal of Food Preservation. 28:29-38.

Interpretive Summary: Moving fruit through a packing facility has long been accomplished using water to transfer the fruit from one location to another. Additional soluble materials (sodium lignin sulfonate, sodium sulfate, sodium silicate, sodium carbonate) are added to the water to increase specific gravity so that the very dense pears will float. Lignin sulfonate (Lignosite) has been used for many years as the standard float material in the pear industry. Recently, the commercial lignin sulfonate product used in pear packing facilities has become expensive and difficult to obtain. In addition some waste treatment plants will not accept lignin sulfonate in waste water. Potassium phosphate (XEDA-F) has been suggested as a possible replacement pear flotation material. Any new flotation material must not impair fruit quality as well as be compatible with packing and storage equipment and procedures. This study was conducted to determine the effects of two commercially available float materials on pear quality as affected by paper wraps and various storage conditions. Float material (Lignosite or XEDA-F) did not influence either objective or subjective quality under either RA storage or up to 200 days CA storage. Type of paper wrap did have a strong influence on pear quality, particularly affecting scald rating and subjective ratings of pear quality. Paper wraps containing Biox A produced pears of reduced quality compared to papers with either 3 or 6% oil with C&E, which were comparable in quality.

Technical Abstract: Thirty bins of commercially harvested `d'Anjou' pears from each of three growers were packed at a commercial packing facility, using one of two pear float materials and wrapping the pears in one of three paper wraps. Float materials used were potassium phosphate (XEDA-F, pH 11.3) or lignin sulfonate (Lignosite), the industry standard. Paper wraps were impregnated with either Biox-A, 3% oil + copper and ethoxyquin (3% C&E), or 6% oil + copper and ethoxyquin (6% C&E). After packing, 36 boxes were placed in regular atmosphere (RA) storage at 1 deg C. Seventy-two boxes were placed in controlled atmosphere (CA) storage (1.5% O2 and 1.0% CO2 at O deg C). After 50 days RA or 100 and 200 days CA storage, fruit were removed and quality evaluated. Float material (Lignosite or XEDA-F) did not influence either objective or subjective quality under either RA storage or up to 200 days CA storage. Type of paper wrap did have a strong influence on pear quality, particularly affecting scald rating and subjective ratings of pear quality. Paper wraps containing Biox-A produced pears of reduced quality compared to papers with either 3 or 6% oil with C&E that were comparable in quality.