Processing, physicochemical and nutritional properties of steamed bread fortified with Chinese Huai-shan Yam

Abstract

Chinese Huai-shan Yams (HSY) is a source of diverse nutrients, such as allantoin, resistant starch, and non-starch polysaccharides, which is the homology of medicine and food in China. Chinese Steamed Bread (CSB) has gained popularity recently. HSY powder was added to wheat flour to make nutritionally fortified CSB. Three flour improvers were used to enhance the dough thermo-mechanical properties, dough rheology, and physical properties of CSB fortified with HSY powder (up to 30 %). The results showed that the combination of 6 % gluten, 0.3 % xanthan gum, and 100 U/kg TGase can greatly improve the quality of CSB fortified with HSY powder (30 %). The specific volume was increased from 2.00 to 2.97 cm3∙g−1 which was 16.7 % higher than the standard CSB with pure wheat flour, while the hardness, adhesiveness, gumminess, and chewiness were decreased to some extent. During storage, the hardness of the improved CSB was significantly suppressed and the enthalpy was significantly decreased. More importantly, the estimated glycemic index of CSB containing HSY and the improved group decreased from 75.4 to 68.1 and 64.8 respectively. The findings indicated the feasibility of formulating HSY-fortified foods with enhanced nutritional quality.

Keywords

• Huai-shan Yam
• Chinese streamed bread
• Thermo-mechanical properties
• Rheological properties
• Estimated Glycemic Index