Vacuum frying is an alternative processing method for producing high quality
snacks with the advantages of lower processing temperature, enhanced organoleptic
quality, and reduced acrylamide content. Vacuum frying (1.33 kPa), with the aid of a deoiling
mechanism, was used to produce low-fat potato chips.
The kinetics of oil absorption and oil distribution in the potato chips (total,
internal, and surface oil content) was studied so that effectiveness of the de-oiling
system could be established. An analysis of product quality attributes (PQA) such as
moisture content, oil content, microstructure, diameter shrinkage, and thickness
expansion, as well as, bulk density, true density, and porosity of chips fried at different
temperatures (120, 130, and 140 degrees C) was performed in order to evaluate the effect of
process temperature on the product. Moreover, heat capacity of the chips and convective
heat transfer coefficient at the oil-chip interface were determined for the same
temperature range.
The final oil content of the potato chips was 0.072±0.004, 0.062±0.003, and
0.059±0.003 g/g solid for frying temperatures of 120, 130, and 140 degrees C, respectively.
These values are lower (80-85 percent less) than those found in traditionally-fried potato chip
which indicates that the de-oiling mechanism is crucial in vacuum frying processing. A
significant difference (P<0.05) was observed in oil content and oil distribution within
temperatures. It was found that the rate of change in PQAs is greatly affected by
temperature; however, the final values of moisture content, bulk density, true density,
porosity, diameter shrinkage, and thickness expansion were not affected by temperature.
During vacuum frying, the specific heat of potato chips decreased with time as
water decreases. The convective heat transfer coefficient changed considerably as frying
progresses; moreover, it increased with temperature reaching a maximum between 2,200
and 2,650 W/m2K depending on frying temperature.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-08-8553 |
| Date | 2010 August 1900 |
| Creators | Yagua Olivares, Carla Veronica |
| Contributors | Moreira, Rosana |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | application/pdf |
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