Konjac black tea(sugar-free) and konjac glucomannan(KGM) solution were studied by using rheometer,refractometer etc.The relationship between their rheological properties and temperature or concentration was discussed ...Konjac black tea(sugar-free) and konjac glucomannan(KGM) solution were studied by using rheometer,refractometer etc.The relationship between their rheological properties and temperature or concentration was discussed in detail.The results showed that viscosity was significantly affected by temperature and concentration;and pH stability of Konjac-tea was related to the molecular property of KGM.展开更多
The objective of this study was to investigate variation and trends in dough rheological properties and flour quality traits in 330 Chinese wheat varieties. The dough rheological properties of development time(DT), st...The objective of this study was to investigate variation and trends in dough rheological properties and flour quality traits in 330 Chinese wheat varieties. The dough rheological properties of development time(DT), stability time(ST), and farinograph quality number(FQN)were evaluated, as well as the flour quality traits of protein(PC), wet gluten content(WGC), and sedimentation value(SV). The coefficients of variation of DT(40.5%), ST(58.1%), and FQN(42.4%) were higher than those of PC(9.1%), WGC(10.1%), and SV(15.3%). Normal distributions were observed for the flour quality indices but not for the rheological parameters. SV was strongly correlated with the three rheological parameters and accordingly might be used as a primary indicator for dough rheological property evaluation. Our results showed that there has been marked improvement in dough rheological properties for Chinese wheat varieties released since 1986, while flour quality has remained stable.展开更多
A series of thermoreversible konjac glucomannan gels crosslinked by organic borate were prepared. Required amount of hydrophilic SiO2 was added into the konjac glucomannan solutions before the crosslinking reaction, T...A series of thermoreversible konjac glucomannan gels crosslinked by organic borate were prepared. Required amount of hydrophilic SiO2 was added into the konjac glucomannan solutions before the crosslinking reaction, The gel network was formed through the crosslinking reaction between borate ions dissociated from organic borate and the cis-diol hydroxyl groups on the mannose units of polysaccharide chains. The rheological properties of the complex gels were studied by dynamic viscoelastic measurement. The gelation kinetics of the complex gels was studied and the critical getation points of the gels were exactly determined by the Winter-Chambon criterion. The effects of temperature and composite ratio on the shear storage modulus （G＇）, the loss modulus （G＂） and the sol-gel transition points were investigated.展开更多
This study makes it possible to establish baking flours of nutritional quality and technologically acceptable following the increase in their rheological parameters due to the insertion of gluten flour. The composite ...This study makes it possible to establish baking flours of nutritional quality and technologically acceptable following the increase in their rheological parameters due to the insertion of gluten flour. The composite flours were obtained using the Philips mixer type (model HR2811). The nutritional qualities of the formulated flours were determined by the Kjeldahl, AOAC 985-29, UV-VIS spectrophotometry (DR 5000;HACH and LANGE, France) and Soxhlet gravimetric methods. The compounds obtained are respectively: Protein, carbohydrate, lipid, micronutrient and vitamin contents. Monitoring the analysis of functional properties (water and oil absorption capacity) as well as baking value.展开更多
Pastry is an essential part of food stuff people like, especially preferring those made of wheat flour: cakes, biscuits, pancakes, etc. The nutritive value of the products mentioned above is not high. Therefore, there...Pastry is an essential part of food stuff people like, especially preferring those made of wheat flour: cakes, biscuits, pancakes, etc. The nutritive value of the products mentioned above is not high. Therefore, there is a need to increase it by adding something like doum fruit (Hyphaene thebaica L.), which is a widespread in Upper Egypt. Doum fruit is a rich source of fibers and antioxidants, also other valuable substances such as carbohydrates and minerals especially potassium (K for people suffering from blood pressure problems). This investigation was carried out to study the possibility of utilization doum fruit powder in cake production. Five levels of wheat flour substitution were used 0%, 5%, 10%, 15% and 20% to produce cake. Also, the effects of blends on farinograph parameters were studied. Results indicated that substitution of doum powder (D.P) led to increase the water absorption (%) and dough weakening (B.U), whereas dough stability (min) was decreased. The water holding capacity of blends increased with increasing the level of substitution. The chemical, physical and sensory characteristics of the prepared cakes were studied. Results showed that increasing the levels of substitution increased the total fat, crude fiber and ash contents in produced cake compared with control. Minerals of the produced cake showed an increment in K and Mg, while slightly increment in Ca, Fe and Zn with increasing the level of substitution. Total phenol and antioxidant activity (AO) increased in substituted cake. Physical attributes of the produced cakes were evaluated and results showed that volume of substituted cakes decreased with increasing the level of replacement except for 10% level it increased. Results of textural analysis showed that D.P fiber decreased all the parameters. Concerning cake color, as the percentage of D.P increased, the color of the cake became darker and had high a and b values. The sensory evaluation results showed an insignificantly decrease in the acceptability by increasing the doum powder substitution comparing with control.展开更多
To promote the commercialization of yellow pea flour(YPF)due to its nutritional benefits.Four biscuits with different YPF ratio(10%–50%)were conducted to explore the optimal addition percentage.The effects of YPF on ...To promote the commercialization of yellow pea flour(YPF)due to its nutritional benefits.Four biscuits with different YPF ratio(10%–50%)were conducted to explore the optimal addition percentage.The effects of YPF on the rheological and baking performance of biscuits were performed.The results showed that the substitution ratio of YPF and milling methods had a critical impact on the rheological properties of dough.The dough stability decreased graduallywhile a softening degree increased with YPF ratio increased.In a term of biscuits,the dimensions of length(L),width(W),thickness(T)and color(L*)of biscuits reduced as YPF addition ratio increased,while colors(a*and b*)and hardness apparently increased.In addition,milling methods had a great influence on the texture and sensory evaluation of four biscuits.The dimensions and color parameters of biscuits from fine flours were larger than that from coarse flours,whereas hardness from fine flours was relatively softer,indicating flour with fine particle size could accelerate the extension and expansion of dough network,and improve Maillard reaction during baking.The highest sensory score for short and tough biscuits was obtained given at YPF ratio of 30%without compromising the qualities of biscuits.展开更多
Baladi bread is a staple food in Egypt and high nutritive value however, stales rapidly. The aim of the study was to conduct a comparative evaluation of pullulan and hydrocolloid combinations on rheological properties...Baladi bread is a staple food in Egypt and high nutritive value however, stales rapidly. The aim of the study was to conduct a comparative evaluation of pullulan and hydrocolloid combinations on rheological properties and quality parameters of wheat-soy baladi bread. Pullulan polysaccharides (Pu) and hydrocolloids as Arabic gum (AG), K-carrageenan (KC), pectin (P), and xanthan gum (XG) were applied. Rheological properties of samples included Pu and hydrocolloids were analyzed through extensiograph and farinograph. The crust color, staling, and sensory attributes of bread were evaluated. Results revealed that wheat flour (WF) has lower water absorption capacity, dough development time, mixing tolerance index, and resistance to extension however, has higher dough stability, extensibility, and dough energy compared to wheat-soy flour (WSF). Pu and/or hydrocolloids addition to WSF dough evidently improved bread quality. Pu was significantly enhanced crust color and yielded fresher bread relative to control. Additionally, Pu showed the highest Alkaline Water Retention Capacity (AWRC) value after 5 days at 25°C ± 2°C. Results demonstrated that hydrocolloids especially pullulan can significantly improve dough properties, baking quality, sensory acceptability, and delay staling of wheat-soy baladi bread.展开更多
为改善乳清分离蛋白凝胶性能并提高其营养特性,将氧化魔芋葡甘露聚糖(oxidized konjac glucomannan,OKGM)与乳清分离蛋白(whey protein isolate,WPI)混合制备复合凝胶,研究OKGM添加量(1%、1.5%、2%、2.5%、3%)对WPI凝胶的持水性、质构...为改善乳清分离蛋白凝胶性能并提高其营养特性,将氧化魔芋葡甘露聚糖(oxidized konjac glucomannan,OKGM)与乳清分离蛋白(whey protein isolate,WPI)混合制备复合凝胶,研究OKGM添加量(1%、1.5%、2%、2.5%、3%)对WPI凝胶的持水性、质构、流变特性、热稳定性的影响,并对复合凝胶的形成机理进行了初步探讨。结果表明,OKGM的添加使复合凝胶的持水性(65.59%~93.42%)显著高于纯蛋白凝胶(53.58%);质构分析发现OKGM添加量为2%时凝胶的硬度、胶着性、咀嚼性达到最大值;流变分析发现复合凝胶是弱凝胶,对高频率和高温具有更高的依赖性;热重分析表明OKGM添加量≤1.5%时,OKGM-WPI复合凝胶的热稳定性均高于纯乳清分离蛋白凝胶;表面疏水性和游离巯基分析发现OKGM的添加降低了表面疏水性和游离巯基含量,说明OKGM与WPI发生交联和聚集形成复合凝胶;扫描电镜观察发现复合凝胶结构更为致密、有序。综上,可以通过添加OKGM改善WPI凝胶性能及稳定性。展开更多
基金National Natural Science Foundation of China(3 0 3 710 0 9)
文摘Konjac black tea(sugar-free) and konjac glucomannan(KGM) solution were studied by using rheometer,refractometer etc.The relationship between their rheological properties and temperature or concentration was discussed in detail.The results showed that viscosity was significantly affected by temperature and concentration;and pH stability of Konjac-tea was related to the molecular property of KGM.
基金supported by the Science and Technology Innovation Project of CAAS for Wang Tianyu (Crop Germplasm Resources Identification and Discovery)
文摘The objective of this study was to investigate variation and trends in dough rheological properties and flour quality traits in 330 Chinese wheat varieties. The dough rheological properties of development time(DT), stability time(ST), and farinograph quality number(FQN)were evaluated, as well as the flour quality traits of protein(PC), wet gluten content(WGC), and sedimentation value(SV). The coefficients of variation of DT(40.5%), ST(58.1%), and FQN(42.4%) were higher than those of PC(9.1%), WGC(10.1%), and SV(15.3%). Normal distributions were observed for the flour quality indices but not for the rheological parameters. SV was strongly correlated with the three rheological parameters and accordingly might be used as a primary indicator for dough rheological property evaluation. Our results showed that there has been marked improvement in dough rheological properties for Chinese wheat varieties released since 1986, while flour quality has remained stable.
基金Funded by Chinese Natural Science Foundation Committee(No.50673080)
文摘A series of thermoreversible konjac glucomannan gels crosslinked by organic borate were prepared. Required amount of hydrophilic SiO2 was added into the konjac glucomannan solutions before the crosslinking reaction, The gel network was formed through the crosslinking reaction between borate ions dissociated from organic borate and the cis-diol hydroxyl groups on the mannose units of polysaccharide chains. The rheological properties of the complex gels were studied by dynamic viscoelastic measurement. The gelation kinetics of the complex gels was studied and the critical getation points of the gels were exactly determined by the Winter-Chambon criterion. The effects of temperature and composite ratio on the shear storage modulus （G＇）, the loss modulus （G＂） and the sol-gel transition points were investigated.
文摘This study makes it possible to establish baking flours of nutritional quality and technologically acceptable following the increase in their rheological parameters due to the insertion of gluten flour. The composite flours were obtained using the Philips mixer type (model HR2811). The nutritional qualities of the formulated flours were determined by the Kjeldahl, AOAC 985-29, UV-VIS spectrophotometry (DR 5000;HACH and LANGE, France) and Soxhlet gravimetric methods. The compounds obtained are respectively: Protein, carbohydrate, lipid, micronutrient and vitamin contents. Monitoring the analysis of functional properties (water and oil absorption capacity) as well as baking value.
文摘Pastry is an essential part of food stuff people like, especially preferring those made of wheat flour: cakes, biscuits, pancakes, etc. The nutritive value of the products mentioned above is not high. Therefore, there is a need to increase it by adding something like doum fruit (Hyphaene thebaica L.), which is a widespread in Upper Egypt. Doum fruit is a rich source of fibers and antioxidants, also other valuable substances such as carbohydrates and minerals especially potassium (K for people suffering from blood pressure problems). This investigation was carried out to study the possibility of utilization doum fruit powder in cake production. Five levels of wheat flour substitution were used 0%, 5%, 10%, 15% and 20% to produce cake. Also, the effects of blends on farinograph parameters were studied. Results indicated that substitution of doum powder (D.P) led to increase the water absorption (%) and dough weakening (B.U), whereas dough stability (min) was decreased. The water holding capacity of blends increased with increasing the level of substitution. The chemical, physical and sensory characteristics of the prepared cakes were studied. Results showed that increasing the levels of substitution increased the total fat, crude fiber and ash contents in produced cake compared with control. Minerals of the produced cake showed an increment in K and Mg, while slightly increment in Ca, Fe and Zn with increasing the level of substitution. Total phenol and antioxidant activity (AO) increased in substituted cake. Physical attributes of the produced cakes were evaluated and results showed that volume of substituted cakes decreased with increasing the level of replacement except for 10% level it increased. Results of textural analysis showed that D.P fiber decreased all the parameters. Concerning cake color, as the percentage of D.P increased, the color of the cake became darker and had high a and b values. The sensory evaluation results showed an insignificantly decrease in the acceptability by increasing the doum powder substitution comparing with control.
文摘To promote the commercialization of yellow pea flour(YPF)due to its nutritional benefits.Four biscuits with different YPF ratio(10%–50%)were conducted to explore the optimal addition percentage.The effects of YPF on the rheological and baking performance of biscuits were performed.The results showed that the substitution ratio of YPF and milling methods had a critical impact on the rheological properties of dough.The dough stability decreased graduallywhile a softening degree increased with YPF ratio increased.In a term of biscuits,the dimensions of length(L),width(W),thickness(T)and color(L*)of biscuits reduced as YPF addition ratio increased,while colors(a*and b*)and hardness apparently increased.In addition,milling methods had a great influence on the texture and sensory evaluation of four biscuits.The dimensions and color parameters of biscuits from fine flours were larger than that from coarse flours,whereas hardness from fine flours was relatively softer,indicating flour with fine particle size could accelerate the extension and expansion of dough network,and improve Maillard reaction during baking.The highest sensory score for short and tough biscuits was obtained given at YPF ratio of 30%without compromising the qualities of biscuits.
文摘Baladi bread is a staple food in Egypt and high nutritive value however, stales rapidly. The aim of the study was to conduct a comparative evaluation of pullulan and hydrocolloid combinations on rheological properties and quality parameters of wheat-soy baladi bread. Pullulan polysaccharides (Pu) and hydrocolloids as Arabic gum (AG), K-carrageenan (KC), pectin (P), and xanthan gum (XG) were applied. Rheological properties of samples included Pu and hydrocolloids were analyzed through extensiograph and farinograph. The crust color, staling, and sensory attributes of bread were evaluated. Results revealed that wheat flour (WF) has lower water absorption capacity, dough development time, mixing tolerance index, and resistance to extension however, has higher dough stability, extensibility, and dough energy compared to wheat-soy flour (WSF). Pu and/or hydrocolloids addition to WSF dough evidently improved bread quality. Pu was significantly enhanced crust color and yielded fresher bread relative to control. Additionally, Pu showed the highest Alkaline Water Retention Capacity (AWRC) value after 5 days at 25°C ± 2°C. Results demonstrated that hydrocolloids especially pullulan can significantly improve dough properties, baking quality, sensory acceptability, and delay staling of wheat-soy baladi bread.
文摘为改善乳清分离蛋白凝胶性能并提高其营养特性,将氧化魔芋葡甘露聚糖(oxidized konjac glucomannan,OKGM)与乳清分离蛋白(whey protein isolate,WPI)混合制备复合凝胶,研究OKGM添加量(1%、1.5%、2%、2.5%、3%)对WPI凝胶的持水性、质构、流变特性、热稳定性的影响,并对复合凝胶的形成机理进行了初步探讨。结果表明,OKGM的添加使复合凝胶的持水性(65.59%~93.42%)显著高于纯蛋白凝胶(53.58%);质构分析发现OKGM添加量为2%时凝胶的硬度、胶着性、咀嚼性达到最大值;流变分析发现复合凝胶是弱凝胶,对高频率和高温具有更高的依赖性;热重分析表明OKGM添加量≤1.5%时,OKGM-WPI复合凝胶的热稳定性均高于纯乳清分离蛋白凝胶;表面疏水性和游离巯基分析发现OKGM的添加降低了表面疏水性和游离巯基含量,说明OKGM与WPI发生交联和聚集形成复合凝胶;扫描电镜观察发现复合凝胶结构更为致密、有序。综上,可以通过添加OKGM改善WPI凝胶性能及稳定性。
