18A-27 |
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F. P. BEJOSANO1, J. N. Alviola2, and R. D. Waniska2. (1) Dept. of Soil and Crop Sciences, Texas A&M Univ., 370 Olsen Blvd., Heep Ctr., 2474 TAMU, College Station, TX 77843-2474, (2) Dept. of Soil & Crop Sciences, Texas A&M Univ., 370 Olsen Blvd., Heep Ctr., 2474 TAMU, College Station, TX 77843-2474 Commercially-produced wheat flour tortillas are made with anti-molding additives thus, they are generally shelf-stable in terms of microbial quality. However, loss in textural quality rapidly occurs during storage which limits the storage stability of tortillas. Such occurrence, often referred to as staling is believed to be caused by starch retrogradation and/or loss of flexibility of the protein matrix. This study was conducted to find ways of preserving the textural quality of wheat flour tortillas during storage. The effect of alpha amylase on reducing tortilla staling due to starch retrogradation was studied. The addition of soy proteins to help improve the stability of the protein matrix in tortillas was also investigated. Alpha amylase and soy proteins were added into a standard tortilla formulation. The tortillas were evaluated for their sensory properties, opacity, diameter and specific volume. Texture measurements were done using the two-dimensional extensibility test with the TA-XT2i texture analyzer and the subjective rollability test. Tortillas with alpha amylase had larger diameter than the control. Most of the soy proteins resulted in softer tortillas although some protein isolates reduced tortilla diameter. Marked improvement in the retention of textural quality during storage was noted in tortillas with alpha amylase alone, and in combination with soy proteins. Control tortillas lost flexibility after 14 d. of storage while those with alpha amylase (with or without soy proteins) remain flexible through 28 d. Thus, with the use of these additives, tortillas with extended storage stability can be produced which benefits both the tortilla manufacturers and the consumers.
Session 18A, Carbohydrate: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |