Color optimization of sweet potato bread for improved consumer acceptance

CHED 1074

Lashawndra Lawrence, lmlawren@aol.com1, Adelia C. Bovell-Benjamin2, Peter Gichuhi2, and Chellani Hathorn2. (1) Tuskegee University, Tuskegee Institute, AL 36088, (2) Department of Food and Nutritional Sciences, Tuskegee University, 300-A Campbell Hall, Tuskegee Institute, AL 36088
Orange-fleshed sweetpotatoes are rich in Beta-carotene, which imparts its orange color to them. Previous work with newly developed sweetpotato breads (SPB) indicated that its color was unacceptable to consumers. The objectives of this study were to: i) modify the color of previously developed sweetpotato breads and evaluate the impact on the loaf volume, color, moisture, vitamin C and Beta-carotene contents of the breads; and ii) assess consumers perceptions of the modified SPBs. Eight bread formulations containing 50 and 65% sweetpotato flour (SPF); dough enhancers without (DE) and with sweetpotato starch (DES); and FDA approved food dyes (at 3:2 ratio of red: green) were prepared and baked in bread machines (subsequent to baking). The loaf volumes, moisture, vitamin C and color of the breads were determined using the seed displacement method, IR-200 moisture analyzer, a chroma meter and 2, 6-dichloro-phenol-indol-phenol titrimetric method, respectively. Beta-carotene was extracted from the samples with 7:3 hexane: acetone and measured spectrophotometrically at 450 nm. Consumers perceptions were assessed in a focus group (n=7). The color of the SPBs was successfully modified from bright yellow to a wheat bread-like color. For the SPBs, the loaf volumes ranged from 1000 to 1200mL, moisture contents were between 30 to 35%, the color L* values ranged from 50.6 to 58.4, and vitamin C content was between 1177.1 and 3251.3 micrograms/100 g. The consumers perceived the color of the 50% SPF bread with DES and dye as awesome. Focus group participants described the texture of the 50% SPF bread with DE and dye as normal. The texture of the breads with 65% SPF, DE, DES and dyes were perceived as too moist, dry, tough and stiff, respectively. Overall, the color of SPBs was successfully modified to a brown-wheat bread-like one, which was perceived as normal by consumers.