Functionality of carbonxymethylcellulose ad soy protein isolates in high-fiber dough systems

The objectives of this study were (1) to investigate the effects of different soy protein isolates (as a replacement for non-fat dry milk solids, NFDMS) and carboxymethylcellulose on various reactions that occur during production of the high-fiber buns and English muffins and (2) to investigate effects of an isolate and CMC on the character-istics of a baked, high-fiber bun with the selection of a soy isolate level as a replacement for part of the CMC and all of the NFDMS as a goal. Effects of soy protein isolate level (SOYC, 0-4.5%, flour weight basis or fwb) and CMC (0-1.5%, fwb) alone and in combination, and soy isolate type (Purina 810 and Supro 610, Ralston Purina, Co.) were deter-mined on viscosity of heated dispersions that contained ingredients present in a high-fiber bun dough (pH 5.35) or a high-fiber English muffin dough (pH 5.15) and on development of both doughs during mixing. Effects of SOYC, CMC and soy isolate type (SOYT) were determined on development of the high-fiber bun dough expansion during proofing. Effects of SOYC (Purina 810) and CMC (0.5-1.5%, fwb) were determined on baked, high-fiber bun characteristics. Increasing CMC increased the temperature of maximum viscosity of all dispersions and, generally, decreased the maximum viscosity value. Increasing SOYC decreased the temperature of maximum viscosity and increased the viscosity of pH 5.35 dispersions only. CMC below 0.5% decreased viscosity at 60 min, but CMC above 1.0% increased viscosity at 60 min. Increasing levels of Supro 610 but not Purina 810 caused increases in viscosity at 60 min. Muffin dispersions (pH 5.15) compared with bun dispersions (pH 5.35) reached maximum viscosity at a higher temperature and had a larger maximum viscosity and viscosity at 50 min. The time to maximum dough consistency (62.5 mm on a mixogram), angle of gluten development, water absorption, peak width at maximum consistency (dough elasticity) and angle of dough breakdown were affected differently by CMC and SOYC among the different dough-SOYT combinations. In three of the combinations, increasing CMC and SOYC did not affect gluten development angle or elasticity but did affect water absorption. Maximum and minimum in response of each of these dependent variables with increasing CMC and SOYC were found and may be related to complex formation between CMC and/or SOYC with dough ingredients. Muffin doughs containing either SOYT and bun doughs containing Purina 810 had larger water absorptions at 1.5% SOYC than at 0 or 3.0% SOYC. This may indi-cate a possible interaction between the soy protein and gluten at 1.5% SOYC. Compared with bun doughs, muffin doughs reached maximum con-sistency faster, had a slower rate of gluten development, required less water to reach maximum consistency, were more resistant to overmixing and were less elastic. Differences between the two doughs may be related to the success of the high-fiber bun formulation in commercial production and the failure of muffin formulation. The spread ratios of doughs proofed up to 60 min were not affected by SOYT but were affected by SOYC and CMC. For doughs proofed 45 and 60 min, increasing CMC decreased the spread ratios and the spread ratios decreased to a minimum at 1.5% SOYC compared with 0 and 3.0% SOYC. This minimum was related probably to the high water absorption of bun doughs containing 1.5% SOYC. For the dough expansion study, bun doughs with 1.5% SOYC probably had a thicker consistency because the large water absorption of this dough was not considered when the doughs were mixed. The data support the complex between soy protein and most likely, gluten, in bun doughs with 1.5% SOYC. In the production of the high-fiber bun, it was found that 6.0% NFDMS and 1/3 of 1.5% CMC in the formulation could be replaced with 1.5% fwb Purina 810 without much change in the bun volume or color. This replacement would decrease the cost of ingredients for production of a package of 12, 56.75 g buns by 3 cents and would increase the mois-ture and fiber content of the bun and decrease the ash content, nitrogen-free- extract and calories of the bun.