Location: Potato, Pulse and Small Grains Quality Research
Project Number: 3060-30600-003-015-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Sep 9, 2025
End Date: Sep 8, 2027
Objective:
To investigate agronomic and post-harvest management practices impacting potato
tuber fry processing quality.
Approach:
Potato tubers will be sourced from one variety from three different field sites at harvest. Tubers will be held at 10C, 12.8C or 15.6C for wound healing before subjecting tubers to two ramp rates, 0.22C or 0.56C, per day. The final temperatures will be either 8.9C or 7.8C. The cooperator will evaluate tuber specific gravity on all samples by the weight in air/weight in water test method. Tuber internal defects including hollow heart, vascular discoloration, heat necrosis will be monitored across all management sampling points. Water loss, dormancy (sprouting), and bruising notes will be recorded at pre-determined storage temperatures and durations. For sugar and fry analysis, tuber samples (8-10 tubers) are washed, cut in half transversely, and a sub-sample is removed from the center of each tuber half to yield 200 g tissue for “bud” and “stem” end samples. After homogenizing in phosphate buffer, the sample brei is brought to 275ml before clarification for 1 hour at 4°C. Sucrose and glucose concentrations are measured using the YSI 2900D immobilized enzyme analyzer. A ‘raw fry’ test will be used to evaluate fry processing quality where 22.2 x 7.9 mm lengthwise potato planks collected from 8-10 tubers/treatment, and planks are batch fried at 190°C for 3.5 minutes. Immediately after frying, photovolt % reflectance (Photovolt, 577, 5G) and plank photos will be collected in a Photosimile 200 lightbox. Sugar, fry color and plank defects of numbered breeding lines will be compared against commercial variety checks.