Development of a Gluten-free Bread with a High-protein Rice Flour and Effects of Alpha-amylase Enzyme Addition

Author

Brandon J. Freire, Louisiana State University and Agricultural and Mechanical CollegeFollow

Semester of Graduation

Fall 2024

Degree

Master of Science (MS)

Department

School of Nutrition and Food Sciences

Document Type

Thesis

Abstract

Gluten-induced conditions such as celiac disease, wheat allergy, and non-celiac gluten sensitivity (NCGS) require the removal of common bakery products, including bread and cookies, and also pasta. The food industry has been developing gluten-free foodstuffs (GFF); however, these have been shown to contain low protein, fiber, and micronutrient levels, while being high in fat content and glycemic index. Bread is a staple food and is the most studied and consumed of GFF. Throughout this study, the flour obtained from a high-protein rice cultivar called Frontière was used for the elaboration of GF breads with the addition of alpha-amylase enzyme to replace starch. Proximate analysis, physico-chemical properties and consumer acceptance were evaluated. Four formulations of bread (T1: white rice flour, T2: white rice flour with α-amylase enzyme, T3: brown rice flour, T4: brown rice flour with α-amylase enzyme) were developed. For the physicochemical analysis, baking loss, specific volume, texture, and color were evaluated. In addition, a sensory analysis was performed. The data were statistically analyzed by ANOVA and LS-means (P < 0.05). Both formulations with α-amylase enzyme (T2 and T4) presented significant (P < 0.05) higher baking loss values (%) than T1 and T3 independently from the type of flour used. Also, formulations T2 and T4 displayed greater specific volume values of the breads (5.78 ± 0.02 cm³/g and 5.73 ± 0.04 cm³/g, respectively) compared to the breads without enzyme. Crust and crumb color reported significant differences (P < 0.05) for L*, a*, and b* values. However, those differences were not associated with α-amylase enzyme addition, but with the type of flour used. For texture, significant lower values (P < 0.05) were found in hardness, chewiness, and cohesiveness for the α-amylase treated breads (T2 and T4). Sensory characteristics were also positively influenced (P < 0.05) by α-amylase addition and purchase intent before and after health claim. The study demonstrated that the addition of α-amylase enzyme in combination with either white or brown high-protein rice flour can improve specific volume values, significantly enhance texture parameters (hardness, chewiness, and cohesiveness), and sensorial properties which are desired attributes in GF breads.

Date

11-4-2024

Recommended Citation

Freire, Brandon J., "Development of a Gluten-free Bread with a High-protein Rice Flour and Effects of Alpha-amylase Enzyme Addition" (2024). LSU Master's Theses. 6038.
https://repository.lsu.edu/gradschool_theses/6038

Committee Chair

King, Joan.