PASTING CHARACTERISTICS OF RICE FLOUR-BASED BATTER COMPARED TO WHEAT FLOUR-BASED BATTER

Rice flour‐based batter (RFBB) formulations were developed for deep fat fried chickendrumstick application. The effects of ingredients on pasting characteristics of RFBB and wheat flour based‐batter (WFBB) were compared using the Rapid Visco‐Analyzer (RVA). Pasting properties were influenced significantly by ratios of rice to corn flour, oxidized corn starch, and methylcellulose. The peak viscosity, breakdown, and setback increased significantly as rice flour level increased, whereas increasing levels of oxidized corn starchyielded opposite results. Pasting characteristics of RFBB were significantly different from those of WFBB.     

Effects of pre-heating temperature and formulation on porosity,moisture content,and fat content of fried batters

The effect of pre-heating temperatures on moisture and fat contents, and porosity of fried batters was studied. Batter pre-heated at 60 °C showed higher moisture content, lower fat content and lower porosity than non-pre-heated batter and batters pre-heated at 70 and 80 °C. Moisture content, fat content, and porosity at 4 min frying for batters with different pre-heating treatments ranged from 35.08 to 39.37, 3.92 to 5.16, and 13.14 to 45.31 %, respectively. Because of significant reduction in fat content, 60 °C pre-heating temperature was chosen to study the effect of batter formulations on moisture and fat contents, and porosity. Different wheat to rice flour ratios were prepared, and then each batter was pre-heated at 60 °C. Batters with higher wheat flour content showed higher moisture content, and lower fat content and porosity than batters with higher rice flour.     

Particle Size Fractionation of High-Amylose Rice (Goami 2) Flour as an Oil Barrier in a Batter-Coated Fried System

The particle size effects of high-amylose rice (Goami 2) flour on quality attributes of frying batters were characterized in terms of physicochemical, rheological, and oil-resisting properties. High-amylose rice flours were fractionated into four fractions (70, 198, 256, and 415 μm) of which morphology was also analyzed by scanning electron microscopy. Rice flour with smaller particle size exhibited a higher degree of starch gelatinization, giving rise to increased pasting parameters. When the rice flours were incorporated into frying batters, higher steady shear viscosity was observed in the batters with finer rice flour, which could be well characterized by the power law model. In addition, the dynamic viscoelastic properties of the batters were enhanced by the use of rice flour with smaller particle size, which also caused an increase in batter pickup. When subjected to deep fat frying, the batters with finer rice flour exhibited reduced moisture loss. Furthermore, the oil uptake was found to have a positive correlation with the particle size of rice flour (R ²?=?0.88), even showing the reduction of oil uptake by 15%. It could be synergistically attributed to the formation of outer starch granular layers, high batter viscosity/pickup, and reduced moisture loss by finer rice flour.     

Textural, Water Holding, and Sensory Properties of Low-fat Pork Bologna with Normal or Waxy Starch Hull-less Barley

All ultra-low-fat (< 1%) pork bolognas had similar cook yield and composition. Addition of 4% hull-less waxy barley flour or meal to formulations provided the greatest purge control; 4% normal starch barley, wheat flour and potato starch were intermediate; 0.25% kappa-carrageenan or 1% soy protein concentrate had little effect on water holding and texture. Expressible moisture and purge were significantly correlated to moisture content and batter viscosity. Formulations with wheat flour and waxy barley meal were scored the firmest, while bologna with potato starch required the most force to compress. For most sensory properties, barley fractions performed similarly to wheat flour; however, waxy barley provided superior water holding during storage.     

Rheological study of layer cake batters made with soybean protein isolate and different starch sources

The study of new gluten-free foods suitable for celiac people is necessary since people allergic to wheat proteins are more and more frequent. This study examined the effect of using different starch sources (rice, corn, potato and wheat) and protein types (soy protein isolate, wheat protein) at different percentages (0%, 10%, 20%), on the rheological properties of batters (flow, viscoelastic and stickiness behaviour) and on batter density and cake volume. The highest consistency, viscous and elastic moduli, and adhesive force corresponded to batters made of rice starch and soy protein isolate, which showed the most similar rheological behaviour to wheat flour batters. The batters obtained showed adequate characteristics in processing and in achieving high quality products. However, the percentages of starches and proteins should be experimentally optimized in each case.     

响应面试验优化肉冻粉配方及其成糊和流变学性质

采用四因素三水平Box-Behnken试验设计,研究用魔芋胶、k-卡拉胶、糯米粉和羧甲基纤维素钠复配成的肉冻粉及其对保水性、硬度、糊化和流变性质的影响。结果表明,魔芋胶、k-卡拉胶和羧甲基纤维素钠添加量对肉冻粉的保水性有极显著影响,魔芋胶、k-卡拉胶、糯米粉和羧甲基纤维素钠添加量对肉冻粉的硬度有极显著影响。糯米粉和羧甲基纤维素钠添加量的增加会使肉冻粉的峰值黏度增大,羧甲基纤维素钠添加量增加使肉冻粉体系的崩解值和回升值均增大,而起始成糊温度降低。保水性和硬度最佳的肉冻粉样品在45～85 ℃均为假塑性流体,并随着温度升高假塑性增强,其动态流变学实验表明,随着温度的降低G’、G”呈增大趋势。     

Characteristics and oil absorption in deep‐fat fried batter prepared from ball‐milled wheat flour

BACKGROUND: The porous structure generated during frying influences oil absorption and textural qualities. The alteration in physical properties of wheat flour is suspected to affect the structure formation. The present study investigated the effect of physicochemical changes in wheat flour by the ball‐milling process on structure formation and consequently oil absorption of a fried wheat flour batter model. RESULTS: Batter models containing 600 g kg^?1 moisture were made of 0–10 h ball‐milled wheat flour and then fried in frying oil at 150 °C for 1–7 min. The samples made of milled flour possess larger pores and exhibit lower oil absorption than sample made of 0 h milled flour. The fracture force of a fried sample prepared from 5 and 10 h milled flour is lower than that of a sample prepared from 0 h milled flour. CONCLUSION: The decrease in glass transition temperature (T_g) and melting temperature (T_m) of milled flour affect the microstructure formation in the fried wheat flour batter. The microstructure is responsible for oil absorption and fracturability in fried food. The samples made of flour of longer ball‐milling time have lower oil absorption and higher crispness. Ball‐milling may be a tool to produce mechanically modified wheat flour which can reduce oil absorption for fried batter. Copyright © 2009 Society of Chemical Industry     

不同粒径分布对全籽粒玉米粉糊化特性的影响

分析不同粒径大小分布对不同淀粉含量全籽粒玉米粉糊化特性的影响,为其品质分析和加工提供参考依据。选取淀粉含量66%~77%的玉米,通过小型实验磨研磨得到不同粒径的全籽粒玉米粉,研究粒径大小分布、主要成分、损伤淀粉等指标对糊化特性的影响。结果表明,玉米粉的粒径大小和分布对其糊化能力、凝胶特性影响明显,特别是小颗粒粒径大小影响明显,但对回生老化特性影响不显著。平均粒径和小颗粒粒径越小、颗粒表面积越大时,越容易糊化,峰值黏度也越大,玉米粉间糊化能力差异越显著,总淀粉越多、脂肪和蛋白越少也越容易糊化,峰值黏度也越大;小颗粒粒径越小、比表面积越大,凝胶抗剪切能力越差,玉米粉间凝胶特性差异越明显,总淀粉和损伤淀粉含量升高、脂肪和蛋白质降低,也降低凝胶抗剪切能力;粒径大小与分布对玉米粉回生老化特性影响不显著,总淀粉和直链淀粉增加、脂肪减少,提高凝胶回生能力。     

Starches and fibers treated by dynamic pulsed pressure

The effect of dynamic pulsed pressure treatment on water activity, moisture content, water holding capacity (WHC), thermal and rheological properties of corn starch, modified corn starch, microcrystalline cellulose and wheat bran were investigated. Substantial changes in moisture content, water holding capacity, water activity, density, shifts in melting patterns, and reordering of molecules resulted from the pressure treatment. The starches and fibers were made into slurries (starches 200 g/kg; fibers 120 g/kg), fed by gravity into the pressure chamber, and pulsed pressure treated at 120 cycles/min; within chamber residence time for pressure treatment was 1.0 s. Dynamic pulsed pressure of 414 or 620 MPa was generated in the chamber. Slurry flow rate through the pressure chamber ranged from 57 to 100 l/h. ¹³C NMR analysis of pressure treated starch showed evidence of pressure induced degradation and loss of long range molecular ordering for modified corn starch. Pressure treatment resulted in increases in density and reduction in water holding capacity of cellulose. A 35% reduction in water holding capacity of cellulose was observed, a significant change (P<0.05) that may potentially increase the amount of cellulose fiber incorporated into foods. Peak melting points of the starches were reduced 10°C at 414 and 620 MPa, and increased with subsequent pressure treatment cycles. The effect of pressure treatment on starches and fibers depend on their source, the degree of pressure treatment, and the number of cycles.     

Gelatinization properties of wheat flour as determined by empirical and fundamental rheometric method

Certain empirical rheological methods are in extensive use in wheat and/or flour research to assess starch gelatinization and pasting behavior primarily due to easy performance and good correlation with final product quality. However, their applications are often associated with specific drawbacks that could be limiting factors for certain applications, such as poor definition of the measured parameters, time-consuming nature, difficulties in interpretation of results, large sample sizes, etc. The listed shortcomings can be overcome by application of fundamental rheological methods that are based on well-defined rheological parameters such as stress, strain, viscosity and modulus. The objective of this study was to optimize the fundamental rheological method for determination of the gelatinization properties of wheat flour that correspondents to the standard widely accepted empirical rheological method—Amylograph method and to compare them in order to determine whether they can be interchangeable depending on different analytical needs. The obtained results have shown that the application of fundamental rheometric procedure for determination of pasting properties of wheat flour provides reliable determination of the gelatinization properties of wheat flour. Moreover, substantial advantages of fundamental rheometric method over the empirical one were identified including smaller sample size, ability to set the desirable heating and shear rate, shorter test duration and better precision.     

Influence of Gluten-free Flours and their Mixtures on Batter Properties and Bread Quality

Gluten is a major component of some cereals and is responsible for flour technological characteristics to make bakery products. However, gluten must be eliminated from the diet of celiac patients because its ingestion causes serious intestinal damage. The objectives of this study were to assess the effect of different flours and their mixtures on thermal and pasting properties of batters, and to study the quality parameters and staling rate of gluten-free breads. Starch gelatinization temperatures and enthalpies depended on batter composition. Soy flour addition had a higher effect on rice than on corn starch, indicating some differential interaction between starch and proteins. Inactive soy flour incorporation improved all bread quality parameters in both corn- and rice-based breads. Higher batter firmness of formulations with soy addition (extrusion force was doubled in rice/soy and rice/corn/soy batters with regard to rice and rice/corn batters) partially explained higher specific volume (rice breads: 1.98 cm³/g; rice/soy 90:10 2.51 cm³/g, corn/soy 90:10: 2.05 cm³/g, whereas corn/soy 80:20: 2.12 cm³/g), as these batters retained more air during proofing. The staling rate was decreased by soy flour incorporation on rice (staling rate of rice breads with 10% soy diminished 52%, and with 20% of soy addition, 77%, both regarding to 100% rice breads) and corn formulation (the staling rate of corn/soy 80:20 breads was 5.9% lower than corn/soy 90:10) because of the high water-holding capacity of soy proteins and the interactions established with amylopectin that could retard the retrogradation process. Breads made with rice, corn, and soy flours showed the best quality attributes: high volume, good crumb appearance, soft texture, and low staling rate.     

玉米粉配比对玉米-小麦混合粉及其馒头品质的影响

采用不同的配比将玉米粉与小麦粉搭配,通过测定玉米-小麦混合粉指标和馒头指标,以研究玉米粉对混合粉及其馒头品质的影响。结果表明:随着玉米粉比例的增加,混合粉的吸水率、稳定时间、粉质指数呈逐渐减小的趋势;最大抗延伸性、拉伸面积、沉降值、湿面筋、面筋指数也逐渐降低;峰值黏度、稀懈值、回升值、降落数值等都有所下降,而糊化温度和弱化度有所上升。玉米粉的使用在一定程度上影响了面团的流变学性能,降低了面筋的品质,但是在比例不超过15%时影响并不十分明显,辅以一定的改良技术,不但可以生产出食用品质优良的馒头,而且可以改善馒头的营养特性。     

蜡质玉米粉的糊化特性研究

为了解蜡质玉米粉及其不同制粉方法对糊化特性的影响,测定了干磨、湿磨、挤压制蜡质玉米粉以及蜡质玉米淀粉、糯米粉的溶胀度和RVA参数。结果表明:蜡质玉米粉糊化进程中溶胀度高,水合能力强,具有较高的糊化参数。不同品种蜡质玉米粉的破损值、谷值、峰值和终黏度的变异程度较大,蜡质玉米粉的峰值与谷值、终粘度和回生值、谷值与回生值、谷值与终粘度、终粘度与回生值均呈极显著正相关。湿法制粉糊化进程中水合能力强,主要RVA参数显著高于干法制粉和挤压制粉,具备很强的成糊能力和黏滞性,干法制粉成糊后稳定较好,抗老化性较强,挤压制粉的糊化进程不明显。     

Rheology and breadmaking performance of rice-buckwheat batters supplemented with hydrocolloids

The aim of this work was to investigate the effects of hydrocolloid addition on rheological properties and breadmaking performance of rice-buckwheat batter at different water levels. Xanthan gum (XG) and propylene glycol alginate (PGA) were added to rice-buckwheat blend (60:40) at levels of 0.5–1.5%. Batter rheological properties were investigated using dynamic measurements in the linear viscoelastic range (frequency sweep and time cure tests). The addition of both hydrocolloids significantly enhanced the storage modulus (G′) of batter. XG exerted greater effect on G′ than PGA. Different effects on starch gelatinisation were observed for the two hydrocolloids. PGA breads showed higher improvement in terms of increased specific volume (V_s), decreased crumb firmness and crumb structure than XG breads. Different technological behaviours were explained on the basis of batter rheological properties.     

百合粉添加量对面团特性及面包品质的影响

为拓宽百合的应用渠道,提高面包的营养价值,研究了百合粉添加量(0%,5%,10%,15%,20%)对面团的微观结构、糊化特性、流变学特性以及面包品质的影响。结果表明:随着百合粉添加量增大,混合粉的持油性先降低后增加,持水性显著增加(P<0.05)。添加了百合粉后,面团的糊化温度升高,回生值和峰值黏度下降,面团的弹性模量和黏性模量均呈上升趋势。百合粉的添加,破坏了面筋蛋白原本均匀致密的微观结构;使面包的硬度显著增大(P<0.05),弹性、内聚性、胶黏性、咀嚼性、回复性、比容和感官评分显著降低(P<0.05);改变了小麦面团的特性和面包的品质,在小麦粉中添加5%~10%的百合粉,能保证面包较高的感官品质。     

The structure of starch granules in fried battered products

This work studies the structure of starch granules during different steps in the production of frozen battered squid rings, using image analysis and microscopy techniques. Frozen battered squid was prepared with four different batter formulations including wheat flour, corn flour, salt and leavening agent and subjected to pre-frying, freezing and final frying to obtain an industrial product. A control product for each of the formulations was prepared with no pre-frying and no freezing steps.The control products, regardless of their formulation, showed most starch components occluded into the starch granules, while the final products presented more leaching of starch components out of the granules. The use of corn flour as an ingredient increased the water retention capacity of the batter, resulting in higher area values for starch granules in formulations where this ingredient is used. There were significant differences between some formulations in the size and shape of the large starch granule population, but no significant differences were observed for the small granule population. As regards the preparation steps, short thermal treatments such as pre-frying mainly affected the large starch granules, which are weaker.     

Exploring the applicability of tamarind gum for making gluten-free rice bread

The present study explored the applicability of tamarind gum in making gluten-free rice bread. Hydration properties of gums and pasting properties of rice flour with the gums were analyzed with Rapid ViscoAnalyzer. Batter properties and bread quality characteristics of rice bread containing gums were analyzed. Except for guar and xanthan gum, the final viscosity after hydration of other gums and the pasting properties of rice flour with the gums were similar. The batter properties and the quality of rice bread containing tamarind gum were equivalent or superior to those containing other gums. Cross-sections of rice bread showed that addition of tamarind gum and pectin resulted in a fine appearance, but pectin may not be preferred due to its lower pH causing unpleasant sour taste and smell of the rice bread containing the gum. Therefore, tamarind gum can be a useful gum for applying to make gluten-free rice bread.     

A rapid batter expansion method for testing the baking quality of wheat flours

A rapid batter expansion method has been described for testing the quality of wheat flour. Batter is prepared by thoroughly mixing wheat flour, baking powder and water which is then transferred to a graduated cylinder. The cylinder is kept in water bath at 40°C and the reading at the maximum expansion is noted down. It has been observed that the batter collapses after reading the maximum expansion, and leaves a mark on the cylinder which also helps in reading the maximum expansion. The results indicate that the batter expansion is highly correlated with bread volume and protein content.     

Pasting,thermal, gel texture,resistant starch and colour properties of unripe banana flour from 10 desert banana varieties cultivated in South Africa

Unripe banana flour is a potential commercial ingredient in various food products for increased resistant starch and reduced gluten contents. In the present study, the pasting (rapid visco-analysis), gel texture (penetration test), thermal (differential scanning calorimetry), colour (tri-stimulus colour indices) and the resistant starch properties of unripe banana flour produced from different dessert banana varieties (n?=?10) cultivated in South Africa, were analysed and juxtaposed to wheat and maize flour. The functional properties varied significantly (p?≤?0.05) between banana varieties, and from wheat and maize flours, to various extents. Selected functional property ranges of unripe banana, wheat and maize flours, respectively included; flour colour index (63.16–76.42, 77.34 and 80.96), paste viscosity (405.5–556.6, 124.7 and 115.6 RVU), gelatinization temperature (64.67–71.21, 71.11 and 69.95?°C), gel firmness (7.24–11.44?×?10^??2 N, 3.49?×?10^??2 N and 6.56?×?10^??2 N) and resistant starch content (19.9–47.4, 2.8 and 2.2% w/w). Multivariate analysis (principle component analysis) showed that the unripe banana flours from different varieties were distinguished from each other based on the pasting temperature. The unripe banana flours were distinguished from both wheat and maize flour based on breakdown and peak paste viscosities. The breakdown viscosity was the most positively related measure to the resistant starch content with a linear regression R-squared value of 0.898, indicating a significant role played by granule structure in resistance to enzymatic hydrolysis. The present research demonstrates that selection of appropriate dessert banana variety is important when replacing staple flours (wheat and maize) with unripe dessert banana flour as a functional ingredient.     

Rheological studies of raw and steamed wheat flour suspensions with added ingredients

The effect of commonly used ingredients such as salt (NaCl) and oil (groundnut oil) or their mixture on the pasting characteristics using a Rapid Visco Analyser (RVA) and the rheological constants of raw and steamed wheat flour has been studied. All the RVA parameters showed greater changes for steamed flour compared to raw flour and also for salt compared to oil. The flour steamed for 15 min exhibited a point of inflection for most of the RVA characteristics. Apparent viscosity and rheological constants showed slight changes at 30% and 33% batter concentrations while much greater changes were observed at a 36% concentration in the presence of the added ingredients. The steamed flour showed slightly lower values of apparent viscosity compared to raw flour in the presence of salt, oil, or their combination, but slightly higher values of rheological constants. However, at a 33% batter concentration, the values showed only marginal changes, which has implications for the product preparations.