39C-11

K. LIMROONGREUNGRAT, Department of Food Science and Technology, University of Georgia, Athens, GA 30602 and Y. W. HUANG.

Sweetpotatoes are economical root crops which contain many significant nutrients including carotenoids, carbohydrates, fibers and vitamins A and C. Small quantities of sweetpotatoes are directly consumed in U.S. due to the lack of product available in markets. In recent years, pasta has gained the popularity in the U.S. However, no pasta product made from sweetpotato flour is available.

The objective of this study was to develop a new value-added pasta product using sweetpotato flour as main ingredient.

Sweetpotato flour, a domestic cultivar (Beauregard) with deep orange flesh, was fortified with two protein sources: wheat gluten (10%) or whey protein concentrate (10%). Tapioca flour (0, 10, 20, 30%) and xanthan gum (2%) were added to increase the firmness and reduce cooking loss, while ascorbic acid (0.1%) and monoglyceride (0.5%) were added to reduce the stickiness of dough. A pilot plant scale pasta machine was used. Cooking loss was determined as total dried residual after cooking. Texture of the pasta was measured by an Instron and Hunter color values were measured using a Chromameter.

Sweetpotato pasta fortified with 10% whey protein concentrate had cooking loss of 13.83% and the shear force of pasta 455.51 N, while pasta that fortified with 10% wheat gluten had 14.77% and 330.58 N, respectively. However, when 30% of tapioca flour was added to the whey protein fortified pasta, the cooking losses of pasta decreased from 13.83 to 9.88%, while the firmness increased from 455.51 to 576.40 N. Color was also affected by tapioca flour addition. The Lightness ("L" value) and yellowness ("b" value) of cooked pasta increased from 61.57 to 64.09 and 48.48 to 50.40, respectively, the redness ("a" value) decreased from 12.47 to 8.85.

The result of this study indicated that sweetpotato flour fortified with whey protein concentrate produced an acceptable product.