Abstract

A simple method is proposed to quantify volume of potato chips by measuring the displaced volume of a finely granular material (rape seeds) by the volume of the chips. Firstly, compaction of the seeds was studied to evaluate the reproducibility and accuracy of the technique. The results obtained indicate an encouraging potential of the technique to estimate the apparent volume of potato chips and give some indications of variation of chip apparent density with some important technological parameters such as chip thickness, frying temperature, and pretreatment of the slices before frying (e.g., blanching). This technique showed that the apparent volume of un-blanched potato slices increased clearly (P = 0.007) with frying temperature (from 120°C to 190°C) until the chips reached final moisture contents <3% (wet basis). For 180 and 190°C, the final apparent volume of these samples indicated that the chips expanded in ?6% beyond its original volume before frying (14.1 mL). For potato slices blanched in hot water (80°C and 3.5 min) and fried under the same temperature intervals and conditions, this trend was not statistically significant (P = 0.088), and the average apparent volume of the chips was 10.9 mL which correspond as an average to a shrinkage of ?23%.