Characterization of product quality attributes of tortilla chips during the frying process
2001
Kawas, M.L. | Moreira, R.G.
Characterization of product quality attributes (PQA) of tortilla chips during frying will provide critical information that can be used to develop fundamental models to describe the structural changes of a fried product during frying. Tortilla chips were prepared from nixtamalized dry-masa flour and fried in fresh vegetable oil for 60 s. The results indicated that most diameter shrinkages of tortilla chips happened during the first 5 s of frying. The chip's thickness increased as a result of crust formation and some bubbles developed at the surface due to gas expansion. The chips become more porous (pore size increased in number and size). The pore size distribution became more uniform (normal) as frying time increased. The chips became crunchier as moisture decreased during frying. The combination of all these quality attributes is responsible for producing the best final product as oil content is greatly affected by the mechanism of structure formation thus resulting in the desired product texture. Fundamental properties such as isotherms and glass transition temperatures were also evaluated. The Crapiste and Rotstein model provided the best correlation at the entire range of moisture content and temperatures. The glass transition temperatures were fitted using the Gordon and Taylor equation. The glass transition curve for the fried chips with total oil content is higher than the one for the chips with partial oil content. A model was developed using the extreme value distribution to predict the pore size distribution of tortilla chips during frying.
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