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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Research Project #433406

Research Project: Effects of Stored Volume on Processing Potato Quality

Location: Vegetable Crops Research

Project Number: 5090-21220-005-15-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2017
End Date: Aug 31, 2019

1. Determine if potatoes stored in small boxes, 1000-lb pallet boxes, and in bulk storage maintain comparable processing quality or if the volume of the stored product influences stored product quality. 2. Provide guidance to industry and other stakeholders on how well processing quality data generated from potatoes stored in small boxes or 1000-lb pallet boxes represents the processing quality of potatoes from commercial scale bulk storage.

All potatoes will be stored at the Cooperator's Potato and Vegetable Storage Research Facility. Two chip processing lines and one fry processing line are proposed for these experiments. Chip varieties will preferentially be those entered into the Potatoes USA Chip Committee NexGen program. Four or five truckloads of potatoes of each line will be stored in bulk storage bins to a pile height of approximately 18 feet. Samples will be removed from each load to create pooled samples for a single 1000-lb pallet box and multiple small crates. At harvest evaluations include measurements of pulp temperature, size profile, specific gravity, as well as a hot box bruise assessment and internal and external defect ratings. A disease-screening sample will be submitted to the Cooperator. Small boxes will be stored in temperature-controlled lockers maintained at 95% relative humidity. Pallet boxes will be stored in ventilated stacks within a bulk bin modified for this purpose. Pallet boxes were used for the first time at the Storage Research facility in crop year 2015 and use was expanded in 2016. Airflow rate through pallet boxes is comparable to that through a bulk pile. All samples will be preconditioned at 55°F, treated with isopropyl-N-(3-chlorophenyl) carbamate to prevent sprouting and ramped to their final storage temperature at 0.2-0.3°F per day. Sugar content of triplicate 6-tuber samples will be quantified monthly using an YSI 2900. Post-fry color will be quantified monthly using a Hunter colorimeter. Specific gravity at harvest and after 3, 6 and 9 months storage will be evaluated using the weight in water/weight in air method. Pressure flattening and bruise evaluations will be conducted on samples from 1000-lb boxes after 3, 6 and 9 months storage, and at the end of storage for bulk bin samples.