Resistant starch （RS） is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco anal...Resistant starch （RS） is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis （RVA） and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS （RS3 and RS2） and three wheat flours. The wheat flours represented strong gluten wheat （SGW）, intermediate gluten wheat （IGW）, and weak gluten wheat （WGW） flours, at different levels of RS substitution （0, 5, 10, 15, and 20%）. The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities ofwheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time （r= 1.000, 0.958, 0.894）, and highly negatively correlated with the mixing tolerance index （r =-0.890）. Data from this study can be used for the development of dough-based products. It also pr展开更多
Fruits of date palm (Phoenix dactylifera L.) are consumed throughout the world and are a vital component of the diet in most Arabian countries. The effect of partial replacement of wheat flour with a 1:1 mixture of wh...Fruits of date palm (Phoenix dactylifera L.) are consumed throughout the world and are a vital component of the diet in most Arabian countries. The effect of partial replacement of wheat flour with a 1:1 mixture of wheat bran and date palm fruit powder on rheological properties of the biscuit dough was studied. Levels of mixture used were 10%, 20%, 30% and 40%. Dough rheology (farinograph, extensograph properties) and biscuit quality (physical properties, colour, sensory evaluation) were assessed. Results obtained indicated that water absorption gradually increased by increasing the levels of wheat bran: palm date powder, meanwhile mixing tolerance index decreased. Dough stability, which indicates the dough strength, also found to decrease by increasing mixture of wheat bran and date powder (1:1). Furthermore, dough development time gradually increased by increasing the mixture at all levels. It was 6.04 min at level of 40% compared to the control (2.5 min). Extensograph results showed that dough energy and dough resistance to extension and proportional number also increased compared with control sample. The proportional number (R/E) ratios increased largely from 3.20 to 5.27 at the level of 40.0%. Ash and fibre contents gradually increased as the mixture levels increased. However, mineral content progressively increased by increasing the level of date powder in the mixture. Incorporation of wheat bran and date powder mixture decreased the spread of the biscuits from 55.66 to 52.82 mm without change in the thickness of the biscuits. Organoleptic properties revealed that quality of biscuits was acceptable at mixture level of 30%.展开更多
基金the National Natural Science Foundation of China （30671270）the National High Technology R ＆ D Program of China （2006AA100101）.
文摘Resistant starch （RS） is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis （RVA） and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS （RS3 and RS2） and three wheat flours. The wheat flours represented strong gluten wheat （SGW）, intermediate gluten wheat （IGW）, and weak gluten wheat （WGW） flours, at different levels of RS substitution （0, 5, 10, 15, and 20%）. The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities ofwheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time （r= 1.000, 0.958, 0.894）, and highly negatively correlated with the mixing tolerance index （r =-0.890）. Data from this study can be used for the development of dough-based products. It also pr
文摘Fruits of date palm (Phoenix dactylifera L.) are consumed throughout the world and are a vital component of the diet in most Arabian countries. The effect of partial replacement of wheat flour with a 1:1 mixture of wheat bran and date palm fruit powder on rheological properties of the biscuit dough was studied. Levels of mixture used were 10%, 20%, 30% and 40%. Dough rheology (farinograph, extensograph properties) and biscuit quality (physical properties, colour, sensory evaluation) were assessed. Results obtained indicated that water absorption gradually increased by increasing the levels of wheat bran: palm date powder, meanwhile mixing tolerance index decreased. Dough stability, which indicates the dough strength, also found to decrease by increasing mixture of wheat bran and date powder (1:1). Furthermore, dough development time gradually increased by increasing the mixture at all levels. It was 6.04 min at level of 40% compared to the control (2.5 min). Extensograph results showed that dough energy and dough resistance to extension and proportional number also increased compared with control sample. The proportional number (R/E) ratios increased largely from 3.20 to 5.27 at the level of 40.0%. Ash and fibre contents gradually increased as the mixture levels increased. However, mineral content progressively increased by increasing the level of date powder in the mixture. Incorporation of wheat bran and date powder mixture decreased the spread of the biscuits from 55.66 to 52.82 mm without change in the thickness of the biscuits. Organoleptic properties revealed that quality of biscuits was acceptable at mixture level of 30%.
