EFFECTS OF SOAKING‐BLANCHING CONDITIONS ON VITAMIN C LOSSES AND OTHER PROPERTIES OF FROZEN FRENCH FRIED POTATOES

Abstract

Kennebec potatoes stored at 10.degree. C for at least 2 mo. were processed into frozen French fries. Potato strips were evaluated after soaking-blanching at temperatures from 25-80.degree. C for periods up to 30 min, after par-frying and storage, and after finish-frying for vitamin C and solids content. Par-fried and finish-fried strips also were evaluated for fat content. Fry color was determined on finish-fried samples. Blanching and finish-frying make significant contributions to the total vitamin C loss of a process. Vitamin C was lost over time during soaking-blanching to the extent of 2.7-68% of the potato''s initial level and the rate of this loss was increased with the use of higher blanch temperatures. Losses due to finish-frying exceeded those due to blanching in many cases. Final vitamin C levels were as low as 9.2% of the original. Soaking-blanching conditions did not affect the solids or fat content of any samples while they did affect finish-fry color. Color lightened with time of soaking-blanching and the rate of lightening increased with the use of higher blanch temperature.