Tortilla chip fried

Figure 18. Tortilla chip fried for one minute and observed directly in an ESEM (A and Q showing the presence of oil in air tunnels. Defatted samples were prepared for conventional SEM observations (B and D). (A x300 B x 25 C x 200 D x 25). [From 63].

Another parameter consideied as constant in most models is thermal omductivity. In lact thmnal conductivity deaeases with frying time, as water is ronoved from the product and oil, which has a Iowct thermal conductivity than water, is absorbed. Thermal conductivity is also affected by other changes that may occur in the food, e.g., starch gelatinization. Results for tortilla chips fried in soybean oil at showed that the thermal conductivity deaeased from 0.23 to 0.09 W m [47]. Most... 

The increase of frying temperature from 150°C to 190°C increased the moisture loss rate the oil absorption rate was not affected during the first 15 s, but the final oil content was higher for tortilla chips fried at higher temperature [49,50], On the contrary, according to Guillaumin [28] a temperature variation between 150°C and 180°C had no significant effect on oil absorption. 

Moreira, R. G., Palau, J., Sweat, V., and Sun, X. (1995a). Thermal and physical properties of tortilla chips as a function of frying time. ]. Food Process. Preservation 19,175-189. 

Tseng, Y., Moreira, R., and Sun, X. (1996). Total frying-use time effects on soybean-oil deterioration and on tortilla chip quality. Int. J. Food Sci. Technol. 31, 287-294. 

Moreira, R. G., Sun, X., Chen, Y. (1997). Faetors affeeting oil uptake in tortilla chips in deep-fat frying. Journal of Food Engineering, 31,485 98. 

Mid-Oleic Sunflower Oil With the relatively recent appearance of mid-oleic sunflower oil, researchers have shown an interest in its use in frying processes. Abidi and Warner (120) used the three types of sunflower oil (regular, high, and mid-oleic) in the preparation of french fries, potato crisps, and fresh white corn tortilla chips. However, no general conclusions may be drawn regarding inherent stability as there is no indication of antioxidant type and concentration in the different oils. 

Industrial frying is one of the major segments in the frying industry. Fried food in the United States and other countries are prepared and marketed in various forms. The most popular of these products is the salty snack food segment. This segment consists of a wide variety of products such as potato chips, tortilla chips, com chips, extmded products, pretzels, fried or roasted nuts, and so on. Out of all these products, potato chips has been known to the people for a long time. 

Special Challenges in Frying Coated Products Several products are easy to handle such as potato chips, tortilla chips, com chips, and so on. On the other hand, the coated products are different and require more involved handling before and during frying. 

This is an important consideration for designing the fryer. For example, tortilla chips show some increase in specific volume after frying. However, the pellets expand tremendously in volume during frying. The internal design of the fryer must accommodate for this increase in volume. Product bulk density also impacts the size of packaging. 

Chen, Y. and Moreira, R. G. (1997). Modelling of a batch deep-fat frying process for tortilla chips. Food and Bioproducts Processing, 75(3), 181-190. 

Kawas, M. L. and Moreira, R. G. (2001). Effect of degree of starch gelatinization on quality attributes of fried tortilla chips. Journal of Food Science, 66(2), 300-306. 

The study of oil uptake during the frying of foods is rather complex and significantly depends on the substrate to be fried. For example, immersion in hot oil causes several transformations within a tortilla chip (McDonough et al., 1993). The oil coats and adheres to the surface of the chip, and free moisture in the chip turns to steam and exits, leaving behind a uniform sponge-like tunnel network. As the steam exits the chip, the oil is drawn inside the tunnels. Starch chains, protein, and lipids interact to form a continuous phase that becomes firm upon dehydration. 

McDonough, C. et al. 1993. Environmental scanning electron microscopy evaluation of tortilla chip microstmcture during deep-fat frying, J. Food Sci., 58, 199-203. 

Moreira et al. [49] observed that moisture loss and oil absorption rates were faster during the first 15 s of frying of tortilla chips and became fairly constant as frying continued. Oil absorption as a function of frying time was described by a first-order exponential equation... 

Potato chips are fried to a final moisture level of 3% or less, which accounts to an of about 0.2. Tortilla chips, com... 

Kawas, M.L. and Moreira, R.M. 2001. Characterization of product quality attributes of tortilla chips during the frying process, J. Food Eng., 47 97-107. 

Moreira, R.G., Palau, J.E., and Sun, X. 1995a. Deep fat frying of tortilla chips An engineering approach. Food TechnoL, 49(4) 146-150. 

Oils were used to fry French fried potatoes and tortilla chips at 190 C. Polar conpounds were detennined by column chromatography. 

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