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Title: TEXTURAL MEASUREMENTS AND PRODUCT QUALITY OF RESTRUCTURED SWEETPOTATO FRENCH FRIES

Author
item Walter Jr, William
item TRUONG, V - NCSU
item ESPINEL, K - KRAFT FOODS

Submitted to: Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2001
Publication Date: 9/30/2002
Citation: Walter, Jr., W.M., Truong, V.D., Espinel, K.R. 2002. Textural measurements and product quality of restructured sweetpotato French fries. Lebensm. Wiss. u. Technol. 35:209-215.

Interpretive Summary: Sweetpotatoes are a nutritious, but under-utilized vegetable. This is due to the fact that preparation of sweetpotato (SP) dishes requires considerable time, while today's consumer has little free time to spend on food preparation. Moreover, there are few processed SP products on the market today, thus limiting consumer options. The reason for the shortage of SP convenience foods is because food processors have not been able to develop products of consistent texture and flavor. To solve this problem our laboratory has utilized restructuring technology. We have developed a system by which cooked SP puree is mixed with gel-forming agents and formed into blocks which are cut into French fry-type strips. These strips are coated with a clear batter which provides a crisp crust and retards penetration of cooking oil into the product. The coated product is then frozen. For consumption, the strips are put into hot oil and cooked at 350 deg F for 1.5 minutes. Our research has shown that consistent texture and flavor can be maintained by employing this technology, and the product is well-liked by consumers. If this technology is adopted by the commercial sector, consumers will be able to purchase a nutritious, high quality, convenience food product, and food processors and SP producers will enjoy expanded marketing prospects. This product, or products of a similar type using restructuring technology, could be made available to consumers at the institutional and retail levels.

Technical Abstract: The objectives of this research were to investigate the applicability of using an alginate-calcium gelling system to produce a French fry-type product using high beta-carotene sweetpotato (SP) puree as the main ingredient and to compare four instrumental methods of texture measurement for this product type in relation to sensory textural properties. SP puree made with Jewel cultivar SPs was restructured using optimized alginate-calcium concentrations. A consumer panel scored SP fries containing 0.35% alginate and 0.5% CaSO4 highest for appearance, texture, flavor, and overall acceptability. A trained texture profile panel described the product with 15 texture notes. Of these attributes, nine sensory notes describing hardness, mastication shear, cohesiveness, springiness, moistness, and oiliness were highly correlated with some instrumental parameters (r = 0.79-0.92) for measuring textural properties. The instrumental methods evaluated were instrumental texture profile analysis, three-point bending force, Kramer shear force, and puncture force. Among these instrumental methods, Kramer shear appeared to be the method of choice because of method's simplicity and high precision (coefficient of variation less than or equal to 10%).