Consumer Packaging and Decay Control of Sweetpotatoes

Report Summary: Packaging sweetpotatoes in consumer-size units has been tried many times since the introduction of plastic films. Heretofore, the development of soft rot in the packaged roots usually prevented successful commercial packaging. Since sodium o-phenylphenate tetrahydrate (SOPP) was found to inhibit decay of sweetpotatoes and a residue tolerance was established by the U. S. Food and Drug Administration, commercial interest in consumer packaging has increased and the SOPP treatment has been tested in conjunction with various types of consumer packages. In numerous laboratory holding tests, Rhizopus soft rot of washed, graded, and packaged roots of several sweetpotato varieties usually was reduced more than 50 percent by SOPP treatment. Other rots were not significantly reduced. Weight loss from sweetpotatoes in polyethylene mesh bags and in bulk was about three times as great as from sweetpotatoes packaged in perforated polyethylene bags. Weight loss from tray-packed roots varied with type of wrap and film used. The tray pack permitted some control of ventilation. A delay in treating sweetpotatoes with SOPP after they were injured in handling reduced the effectiveness of the treatment. The effectiveness of the treatment depended upon the temperature at which roots were held after injury and the elapsed time before treatment. The SOPP treatment reduced soft rot even in chilled sweetpotatoes, but control of soft rot in severely chilled roots was not satisfactory.