Effect of Hydrocolloids on the Characteristics of Gluten-Free Bread from Coix Seed Flour

Abstract

The demand for gluten-free bread had increased because of the healthier lifestyle. Some people were intolerant to gluten which led to celiac disease. However, the gluten-free bread typically performed low specific volume, dense and crumbly texture. Hydrocolloids were commonly used as an ingredient to replace gluten, leading to improvement of the gluten-free bread quality. This study aimed to develop gluten-free bread from coix seed flour with the addition of hydrocolloids. The effects of using different hydrocolloid types (Xanthan gum (XG) and Hydroxypropyl methylcellulose (HPMC)) and contents (0.5–2%) on the physical and sensory qualities of gluten-free bread were investigated. Hydrocolloid type and content affected the physical qualities of gluten-free bread. The hardness, specific volume, lightness and whiteness index of gluten-free bread containing XG were higher than those of gluten-free bread containing HPMC. Increasing hydrocolloid contents (XG 0.5–2% and HPMC 0.5–2%) significantly decreased the hardness (p ≤ 0.05). In contrast, the springiness, specific volume, lightness and whiteness index were significantly increased (p ≤ 0.05), whereas the water activity was not significantly different (p > 0.05). In sensory evaluation, the appearance, taste, aroma, flavor, softness, firmness and overall liking scores of all gluten-free breads were not significantly different (p > 0.05). The overall liking scores ranged from 5.70 to 6.14. Additionally, the gluten-free bread containing 1% HPMC was selected as the most appropriate formulation because it received the highest mean overall liking score (6.14) while maintaining desirable physical properties.