Effect of cellulase on dough structure and quality characteristics of tough biscuits enriched with potato whole flour.

Potato whole flour is a promising way to improve the nutrition of tough biscuits, while its gluten-free characteristic was difficult to form acceptable texture properties. In this study, cellulase was used to degrade the cellulose in dough enriched with potato whole flour, so as to mitigate the interference of cellulose with the gluten network, resulting in forming the potato whole flour biscuit with great characteristics. Results indicated that cellulase within 0.2% led to the gradually reduced G' and G'' values of dough from 5.50×104 to 4.00×104 and 2.66×104 to 1.35×104, respectively. Cellulase at 0.2% resulted in the significantly increased tensile properties of the dough compared to the control. The incorporation of cellulase within 0.2% also led to the tightly ordered and intact network structure base on the results of SEM, disulfide bonds determination and FTIR. Those results indicated that cellulase was beneficial to improve the baking quality of dough, which was conductive to form tough biscuit with great characteristics. The hardness, crunchiness, crispness and specific volume analysis results confirmed that 0.2% cellulase resulted in the significantly decreased hardness by 45.25% and the significantly increased specific volume, crunchiness and crispness by 24.74%, 121.20% and 156.47%, respectively. Overall, cellulase ultimately improved the quality of the biscuits by improving the properties and structure of the dough. It was of great significance for the utilization of potato whole flour resources and the industrial production of its tough biscuits. PRACTICAL APPLICATION: The results showed that inclusion of cellulase led to the reduced hardness and increased crunchiness, crispness, and specific volume of potato whole flour tough biscuits. Cellulase could be used as a potential improver of tough biscuits. This study will provide guidance for practical uses of cellulase in improving potato whole flour dough and tough biscuit quality.

Liu X ，Zhu X ，Zhu Y ，Wang C ，Li H ，Chen S ... -  《-》

Effects of whey and soy protein addition on bread rheological property of wheat flour.

The development of wheat-based foods that are enriched with proteins is increasingly popular due to consumer demand regarding food nutritional content and quality. This study was performed to compare the effect of whey and soy protein on the rheological properties of wheat dough and bread-making quality in a relatively wide range of protein addition (0-30%). We found that the incorporation of whey protein (WP) decreased dough stability time (MST), minimum torque (MMT), G' and G″, but increased dough peak torque (MPT), stickiness, G' and G″ in temperature sweep. With the increasing level of WP from 0 to 30%, the specific volume of bread initially decreased from 2.61 to 2.22 cm3 /g, then increased to 3.08 cm3 /g when WP was at higher concentration than gluten. However, the crumb hardness increased from 173 to 1291 g at the same time. As a contrast, the addition of soy protein (SP) increased dough MST, MMT, G' and G″, but decreased MPT, stickiness, G' and G″ in temperature sweep. With the increasing level of SP from 0 to 30%, the specific volume of bread decreased from 2.61 to 1.31 cm3 /g and the hardness first decreased from 173 to 152 g, then increased to 696 g. The results suggested that selection of the protein source and amount with appropriate functionalities played an important role in certain applications for protein fortified bakery products. Since it is known that the gluten network is responsible for viscoelastic properties in wheat dough and for dough structure strength and gas retention, most studies reported that enrichment of foreign proteins interfered with gluten development and therefore, had negative effects on bread quality. This study compared the effects of whey and soy proteins on the thermomechanical, dynamic rheological and microstructural properties of wheat dough and bread-making quality in a relatively wide range of protein addition (0-30%). The results suggested that selection of the protein source and amount with appropriate functionalities significantly affected the structure of the dough and quality of the bread. Our study is essential for product development and process control when considering the popularity of protein fortified bakery products.

Zhou J ，Liu J ，Tang X 《-》

Gluten-free biscuits based on composite rice-chickpea flour and xanthan gum.

Benkadri S ，Salvador A ，Zidoune MN ，Sanz T ... -  《-》

Effects of component ratios on the properties of sweet potato-oat composite dough and the quality of its steamed cake.

To enhance the value proposition of sweet potato and oat while broadening their applicability in further processing, this study systematically investigated the impact of oat flour incorporation ratios (5%-25% of sweet potato dry weight) on the quality attributes of sweet potato-oat composite dough and its resulting steamed cake products. The results showed that the addition of oat flour could promote the rheological, water retention, and thermomechanical properties of the composite dough and improve the internal microstructure, specific volume, texture, and other processing properties of the steamed cake products. The rheology, water retention, and protein stability of the dough were maximized when the proportion of oat flour was 25%. The textural properties of steamed cakes, hardness, elasticity, cohesion, adhesion, chewiness, and recovery significantly increased (p < 0.05) and viscosity significantly decreased (p < 0.05) with the addition of oat flour. It is noteworthy that thermodynamic properties, internal structure of the dough, and air holding capacity, which are critical for processing, showed the best results at 20% oat flour addition. Therefore, the addition of 20%-25% oats is recommended to produce composite doughs with optimal quality and processing characteristics. PRACTICAL APPLICATION: As living standards improve, traditional cereals may no longer able to meet people's health needs. Therefore, there is an urgent consumer demand for nutritious, tasty alternatives to staple foods. In this study, oat flour and sweet potato mash were mixed to make sweet potato-oat cake, and the effect of ingredient ratio on the performance and quality of composite dough containing sweet potato-oat flour was analyzed, thus proposing an innovative approach to the research, development, and industrial production of sweet potato and oat food products.

Wei X ，Ren G ，Liu W ，Zhao M ，Xu D ... -  《-》

Valorizing date seeds through ultrasonication to enhance quality attributes of dough and biscuit, Part-1: Effects on dough rheology and physical properties of biscuits.

In the present study, non-conventional and green technology (ultrasonication) was utilized to recover bioactive compounds from the small, medium and large sized defatted date seed powder (DDSP) particles. Bioactive compounds recovered from DDSP and the remaining fiber-rich residue were incorporated as functional ingredient in the biscuit dough to enhance the functionality and the quality characteristics of the dough and biscuit. The polyphenolic extract and 2.5 %, 5 % and 7.5 % substitution levels of fiber-rich extraction residue were incorporated in formulations followed by investigating the effect on rheological, physical and microstructural properties of dough and biscuit. Loss and storage moduli, G'' and G', respectively, of dough increased with decreasing particle size and increasing substitution level while tan δ decreased with increasing substitution level of fiber-rich extraction residue. The smallest particles at 7.5 % substitution level resulted in the lowest creep strain value in dough. Hardness of the dough and biscuit increased with decreasing particle size and increasing substitution level of the residue. The 7.5 % substitution level of the smallest particle size resulted in the darkest dough and biscuit. Spread ratio and diameter of the biscuit decreased with increasing substitution level of the residue. The smallest diameter of 50.61 mm and spread ratio of 8.36 was observed in the biscuits substituted with the largest particle size with 7.5 % substitution level. Microstructural images of dough and biscuit revealed that the continuity of the gluten network was disrupted by the incorporation of the fiber-rich extraction residue. This study provided valuable insights into extracting bioactive components from date by-products using green ultrasonication technique and utilizing such compounds to improve functional attributes of bakery products, as a sustainable approach for valorizing date by-products.

Ranasinghe M ，Stathopoulos C ，Sundarakani B ，Maqsood S ... -  《-》