Chapatti quality from British wheat cultivar flours

The aim was to study wheat flour parameters relevant to suitability for production of chapattis, made from British wheat cultivars. Wholemeal flours from eight British cultivars grown in UK differed in physicochemical and rheological properties, and were less suited to chapatti production than Mehrani, commercial wholemeal chapatti flour. Chapatti quality of Mehrani wholemeal flour was rated as excellent, hence this was used as a benchmark. Flours from cultivars Riband and Galahad gave weak dough whereas those from Fresco and Mercia yielded dough high in resistance to sheeting that contracted after rolling. Dough from Avalon, Hereward and Pastiche had moderate resistance to sheeting properties. Changes in softness of chapatti during storage were evaluated using an Instron testing machine. Evaluation by sensory panel indicated that all cultivars produced chapattis that were fair to good in sensory characteristics. Some correlations were found between sensory and instrumental attributes of chapatti.     

Effect of microwave heating of wheat grains on the browning of dough and quality of chapattis

Studies were conducted to evaluate the effect of microwave (900 W, 2450 MHz) heating of wheat grains conditioned to different moisture levels on the activity of polyphenol oxidase (PPO) and subsequent colour changes during storage of wheat dough. The results showed that microwave heating of wheat grains for 80 s decreased the PPO activity significantly ( P  ≤ 0.05) with an increase in moisture level from 12 to 18%. Whole wheat flour milled from microwave treated wheat grains (80 s, 18% MC) had 93.39% less activity of PPO. The dough balls (40 g), pressed and rolled into circular form (150.00 mm diameter and 2.00 mm thickness) and stored at 5–6 °C for 72 h. The colour of flattened circular dough was measured using Hunter Colour Meter and it was found that L -value (lightness) decreased from 64.21 to 60.23 in treated and from 64.79 to 47.93 in control samples after 72 h of storage. The results showed that the microwave heating effectively controlled the enzymatic browning in dough and improved the consumer acceptability of chapattis prepared from the same during refrigerated (5–6 °C) storage for 72 h.     

Influence of detoxified Indian vetch (Lathyrus sativus L.) on sensory and protein quality characteristics of composite flour chapatti

We studied the effects of different processing treatments, including soaking, steeping, boiling in water and germination and chemical treatments with H₂SO₄, HCl, lime and NaHCO₃, on the removal of a neurotoxin, β‐N‐oxalyl‐L ‐α,β‐diaminopropionic acid (β‐ODAP), from Indian vetch (Iv) and addition of detoxified Iv in chapatti. The toxin level was quantified by using thin‐layer chromatographic and spectrophotometric methods. Maximum removal was observed after steeping in water at 60–70°C for 8 h with seven rinses. The samples were dried, milled into flour and added to chapatti at different levels. Sensory attributes revealed that the chapattis were most acceptable by judges when supplemented with up to 200 g kg⁻¹ of flour. The protein level of Iv flour increased from 124 to 174 g kg⁻¹ as result of supplementation at 300 g kg⁻¹. Biological studies with albino rats showed that detoxified Iv had a better impact on nutritional status. Copyright © 2006 Society of Chemical Industry     

Prediction of the degree of starch gelatinization in wheat flour dough during microwave heating

In order to produce quick-boiling noodles, we made partially pre-gelatinized wheat flour dough by the microwave heating method. A cylindrical-shaped piece of wheat flour dough containing 3% NaCl was heated by 117 W microwave oven operating at 2450 MHz. The sample dough was intermittently heated to allow sufficient gelatinization of the starch granules of the dough. The resultant changes in the internal temperature profiles of the sample dough were measured and compared with numerical prediction, which is the two-dimensional heat conductive equation with a term for internal heat generation based on Lambert’s law. In order to calculate the internal heat generation during microwave heating, we measured the dielectric properties of wheat flour dough at 2450 MHz from 10 to 70 °C by the open-ended coaxial probe method. The calculated temperature history could describe the feature of the experimental one during intermittently microwave heating. Furthermore, the progress of starch gelatinization according to the heat transfer in the sample dough was predicted by the Runge–Kutta gel method. A tendency that the total gelatinization degree increased slowly during the microwave intermittent heating was obtained in the calculated result.     

Optimisation of flours for chapatti preparation using a mixture design

A mixture design was evaluated for the preparation of composite chapatti flours from two wheat cultivars, Mercia and Galahad, as single cultivars did not yield flours suitable for chapatti production. Physicochemical and rheological tests were applied to determine flour quality. Dough development time (Peak time) and dough stability increased and tolerance index decreased with increasing level of Mercia in the composite flour. Instron and sensory tests were applied to evaluate changes in softness of chapattis at different intervals of storage. Maximum response in texture softness was found with 500 g kg^?1 Mercia in the composite flour. Dough prepared from this composite flour showed low stickiness, moderate sheeting resistance and moderate subsequent shrinkage, making it of suitable sheeting quality for chapatti production. It yielded chapatti of soft texture whose scoop formation capability did not change significantly during storage. Copyright © 2006 Society of Chemical Industry     

全麦粉对油条面团和油条质量的影响

本文研究了全麦粉对油条面团流变学和糊化特性的影响,并在此基础上,研究了全麦粉对油条品质(膨胀性、色泽、质构、含油量)的影响。研究结果显示,随着全麦粉替代油条配方中精制小麦粉比例的提高,面团的形成时间从16.03 min下降到11.33min,稳定时间从18.23 min下降到10.24 min,而面团的吸水率由64.87%上升到76.33%。油条粉的糊化特性也受到全麦粉的显著影响,特别是峰值粘度从1160下降到990.7(RVU)。对于油条产品来说,100%全麦粉取代率制得油条的比容仅为3.01 cm3/g。同时全麦粉的加入使得油条表面的色泽变暗,L*值从73.42显著下降到57.89,油条的含水量由28.04%上升到34.09%。此外,油条的质构也受到全麦粉的影响,特别是100%全麦粉油条的硬度几乎是空白的5倍(由2490.45 g提高到11958.38 g)。更重要的是,空白油条的总含油量为19.60%,而100%全麦粉取代率的(油条的总含油量仅为11.25%。分析看出,全麦粉取代率与油条的含水量存在正相关关系(r=0.869),与油条的比容(r=0.995)、表面含油量(r=0.942)及结构含油量(r=0.951)存在负相关关系。因此,从本研究的结果看,全麦粉的加入可以用来生产一种低含油量高营养价值的全麦油炸产品。     

Effect of fortification on physico-chemical and microbiological stability of whole wheat flour

Stability of fortified whole wheat flour (WWF) was evaluated using NaFeEDTA, elemental iron, ZnSO₄ and ZnO as fortificants. Fortified WWF was stored in tin boxes and polypropylene bags for 60 days under ambient storage condition (ASC) and controlled storage condition (CSC). Fortification significantly (p ? 0.05) decreased moisture and protein content and increased ash content to 5.44%, 6% and 23%, as compared to control. Fortified WWF, assayed periodically for mould contamination manifested a significant inhibition (∼1 log reduction) in flours containing elemental iron. Low storage temperature and relative humidity (RH) indicated lower level of mould count during extended storage time. Tin boxes, as storage material, exhibited a better protection against mould attack, acting as an effective barrier for moisture. Fortificants exerted a slight deteriorative effect on texture characteristics of the chapattis made of these flours but chapattis were still accepted by the judges. Zinc fortificants seemed like having little or no effect on the quality of the flours and chapattis, made of such flours. Shelf life of fortified flour may be extended by using elemental iron as fortificant and storing the product in tin boxes under relatively low temperature and RH.     

Effects of Waxy Wheat Flour and Water on Frozen Dough and Bread Properties

ABSTRACT:  The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation ( T ₂) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T ₂. Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.     

全麦粉对石梅盘香饼面团及其产品品质的影响

以全麦粉取代石梅盘香饼配方中不同比例的精制面粉,研究面团及产品品质的变化,以感官评定为指标,确定石梅盘香饼中全麦粉的最佳取代量以及工艺。结果表明:当全麦粉取代率从0%提高到100%时,吸水率上升了9.5%,面团的形成时间提高了3.9倍,粉质质量指数增大了4.5倍;面团醒发135min时,与空白相比,100%全麦粉取代率的面团延伸度从98.00 mm降到74.00 mm;同时,100%全麦粉的取代使得混粉的峰值黏度和衰减值分别降低了54.5%和38.0%。最后,优化得到了全麦石梅盘香饼的配方为:全麦粉80g,小麦粉20g,鸡蛋10g,细砂糖15g,黄油15g,水52g,采用小包酥和擀卷起层结合的起酥工艺,得到品质优良的全麦石梅盘香饼。     

Use of response surface methodology to investigate the effects of milling conditions on damaged starch,dough stickiness and chapatti quality

Response surface methodology was used to investigate the influence of three factors namely mill aperture, feed rate and moisture content of wheat grain on the damaged starch content of whole wheat flour from Lokwan wheat cultivar, dough stickiness and chapatti (Indian unleavened flat bread) quality. Each predictor variable was tested at three levels. Aperture was varied as 2, 3 and 4 mm in a stone mill, feed rate as 0.21, 0.63 and 1.05 min for 200 g wheat grains and grain moisture content as 8.6, 14.3 and 20% w/w. Flours containing varying amounts of damaged starch ranging from 6.1% to 26.90% were obtained and these were evaluated for dough stickiness and chapatti quality. Dough stickiness was increased with decreased aperture. With decreased aperture and increased grain moisture content softness of the chapatti was improved.     

PHYSICAL, CHEMICAL AND SENSORY QUALITY OF MICROWAVE-BLANCHED SNOW PEAS

Snow peas were blanched using four methods [conventional boiling water (BW); steam (ST); microwave (MW); and microwave blanched in heat sealable bags (MWB)], then held frozen at (～18C) for four weeks. Immediately after blanching, MWB‐blanched snow peas retained more reduced ascorbic acid (RAA; 72%), than other treatments. Blanching treatment had no effect on lightness [L* value). With the exception of BW‐blanched peas, blanching significantly altered color. After frozen storage, MWB‐ and MW‐blanched samples both contained about 26 mg/100 g RAA, significantly more RAA than other treatments. MWB‐blanched peas generally had as high or higher sensory appearance, aroma, flavor, texture and general acceptability scores than other treatments. These results imply that blanching snow peas in a heat‐sealable microwave bag, prior to frozen storage, produces a product of equivalent sensory quality and superior nutritional quality compared with more conventional blanching methods.     

Effect of butter content and baking condition on characteristics of the gluten‐free dough and bread

This study aimed to investigate effect of butter content (0–30 g/100 g flour) and baking conditions hot air baking (HA), microwave baking (MW) and hot air‐microwave baking (HA‐MW) on quality of the rice flour dough and bread. The increased butter (up to 15 g butter/100 g flour) enhanced elastic modulus (G′) and viscous modulus (G″) of dough and specific volume of bread. Additionally, the increased butter improved crust colour and reduced hardness of the bread. The HA‐MW and MW conditions were useful for the gluten‐free bread by reducing baking time and predicted glycemic index (GI), regardless of butter content. However, enthalpy of retrogradation and crystallinity in the HA‐MW and MW bread stored at 4 °C for 7 days were increased and higher than those of the HA bread, indicating a faster staling. The predicted GI of both MW and HA‐MW bread remained at a medium level during storage.     

Dough and bread qualities of flours with whole waxy wheat flour substitution

Whole wheat flour has been developed as fiber-rich food for healthy bowel function. In this study, whole waxy wheat flour (WWF) was characterized and applied for breadmaking with the hope that breads made from WWF would improve the quality based on the superior properties of the waxy flour in retardation of bread staling. WWF had significantly higher protein, ash and dietary fiber contents (13.5%, 1.6% and 15.3%, respectively), but lower lipid content (0.8%) than commercial white flour (CWF). Amounts of soluble and insoluble dietary fiber in WWF were 4.1% and 11.2% (% total weight), respectively. WWF had lower pasting temperature and viscosities than CWF. Dough made from WWF increased water absorption and showed lower stability during mixing than that from CWF. The high amount of dietary fiber diluted the gluten protein in dough during mixing to form weak and inextensible dough. Bread made from whole waxy wheat flour had significantly low specific volume and big gal cell distribution as compared to that from CWF. Also, dark-brown color and bitter taste are weak points of whole waxy wheat bread. However, the WWF bread was significantly softer than CWF bread during storage. The qualities of breads were also improved using partial WWF substitution (10%, 30% or 50%) for CWF. As a result, whole waxy wheat flour can be used for breadmaking to improve nutritious quality of bread for health benefits.     

Cooking evaluation of crayfish (Procambarus clarkia) subjected to microwave and conduction heating: A visualized strategy to understand the heat-induced quality changes of food

The evaluation of food cooking process is an important way to understand the heat-induced quality changes and optimize the heating process. To understand the quality changes in crayfish tail heated by microwave (MW) and boiling water (BW), the protein denaturation, cooking uniformity and overheating degree of tails were visually evaluated based on the theories of reaction kinetics and maturity value in this work. Protein denaturation analysis showed that heat-induced protein denaturation in crayfish tails heated by MW and BW followed first-order reaction kinetics and had similar one-dimensional denaturation patterns and temperatures, but their distributions were non-uniform and with reverse trends. Moreover, strong correlations between protein denaturation degree and heat-induced qualities changes were observed in crayfish tail during heating. The cooking uniformity and overheating degree of crayfish tail heated by MW and BW were evaluated by the maturity value (M_v) and overheating value (O_v), respectively. Evaluations showed that the profiles of M_v and O_v in the crayfish tail were non-uniform and with reverse trends, and there was lower ΔM_v and ${\overline{\mathrm{O}}}_{\mathrm{v}}$ for crayfish tail heated by MW than by BW, but higher O_v occurred in the centre, which corresponded to the texture of crayfish tails heated by MW was more susceptible than by BW when proteins had completely denatured.Industrial relevanceThe general patterns of cooking process in crayfish tail during microwave heating and boiling have been visually evaluated and compared based on the theories of reaction kinetics and maturity value, which enriched the knowledge for the application of microwave in the industrial thermal processing of crayfish and reaction kinetics in the analysis of cooking (especially microwave heating). Furthermore, the theory of maturity value was introduced into the evaluation of the cooking uniformity and overcooked degree in crayfish tail during the heating, which provided a new strategy for the cooking evaluation of food.     

微波处理对全麦粉理化性质及全麦鲜湿面品质的影响

为解决全麦粉加工品质和储藏稳定性的不足,采用微波处理全麦粉,用粉质仪和动态流变仪研究微波处理对全麦面团流变学特性的影响;用快速黏度分析仪(RVA)、X射线衍射仪、SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)等分析全麦粉中淀粉和蛋白组分结构和理化性质的变化;并验证了微波处理对全麦粉中微生物和多酚氧化酶的抑制效果和对全麦鲜湿面品质及褐变程度的影响。结果表明,微波处理可以显著提高全麦面团的稳定时间,增加面团的弹性和类固体性质,同时可改善全麦粉的黏度特性,使淀粉结晶特性略有提高;SDS-PAGE图谱显示,微波处理可引起全麦粉中蛋白组分发生有限聚合,这种聚合作用主要由二硫键引起。微波处理能够显著降低全麦粉中的菌落总数和PPO活性,抑制全麦鲜湿面褐变,提高面条煮后拉断力。     

微波处理对小麦粉品质的影响

为了改善小麦粉的品质,研究了微波处理对小麦粉糊化特性、质构特性和粉质拉伸特性的影响.结果表明:微波处理后小麦粉的糊化温度降低,黏度和回生值升高.经微波处理的小麦粉凝胶硬度和回复性下降,弹性和内聚性无显著差异.小麦粉经微波处理后面团吸水率和跌落值D250降低,面团的稳定时间延长.微波处理后小麦粉面团的抗拉强度、弹性强度明显增强,而面团延伸度有明显下降.初步研究认为,在微波功率400 W,处理时间为6 min时小麦粉的品质有明显改善.     

Effects of fine grinding of millfeeds on the quality attributes of reconstituted whole-wheat flour and its raw noodle products

Effects of millfeed particle size on the quality of whole-wheat flour (WWF) and raw noodles were investigated. Four ranges of particle size distribution of millfeeds from hard red spring (median diameter: 307, 260, 225, and 178 μm) and hard red winter (median diameter: 319, 274, 235, and 185 μm) were obtained by fine grinding. For both wheat classes, the CIE L* values of WWF decreased and a* and b* values increased with the reduction of millfeed particle sizes. WWF with finer millfeeds exhibited higher PPO activity than that with coarser millfeeds. RVA analysis showed that peak viscosity, trough, and final viscosity of WWF significantly decreased as the particle size of millfeeds reduced, while breakdown and setback values revealed no obvious trend. Reducing the particles of millfeeds not only significantly increased the Farinograph stability time of WWF dough, but also improved the whole-wheat noodle (WWN) brightness (L*) at both 0 and 24 h. Texture profile analysis of cooked noodle indicated that hardness, springiness, cohesiveness and resilience values all significantly increased as the particle sizes of millfeeds were decreased. These results suggest that reduction of millfeed particle sizes before reconstituting WWF could provide beneficial effect on the quality improvement of WWN.     

Heating Conditions and Bread-Making Potential of Substandard Flour

ABSTRACT Heating weak bread flours (commercial cookie flour; commercial stone‐milled bread flour; Fundulea, a weak bread cultivar) at 80°C for 15 min had a positive effect on bread volume (P < 0.05). This positive effect was best seen when ascorbic acid was removed from bread formulation. Crumb springiness and fineness of grain, but not crumb hardness, were significantly improved after flour heating; cohesiveness improved with heated cookie flour (P < 0.05). After heating, flour a‐amylase content was lower; dough‐mixing stability of cookie flour doubled to 7.1 min but dropped from 18.0 to 4.8 min with standard bread flour. Heating offers possibility to upgrade substandard flour for bread‐making applications, especially in oxidant‐free dough system.     

Extending shelf life of chapatti by partial baking and frozen storage

The effect of conventional and partial baking and storage at two different temperatures (ambient and −18 °C) on the texture of wheat flour chapatties was evaluated using tensile deformation and the extent of retrogradation was studied using DSC. The extensibility of the conventionally baked chapatti decreased by 58.7% and 20.15%, respectively after storage of 24 h at ambient and frozen temperature. The partially baked chapatti showed a much lower decrease of 3.7% and 0.01% in extensibility when stored under the same conditions. Chapatties, both conventionally and partially baked stored at ambient temperature showed higher retrogradation enthalpy than their counterparts kept at −18 °C. Extended frozen storage of the chapattis from partially baked chapatti resulted in a progressive increase in the extensibility whereas the extensibility of the conventionally baked chapatties was not affected. Lowest water absorption index of 4.60 was observed in partially baked chapatti stored for 24 h at ambient temperature indicating that maximum retrogradation (4.19 J/g) had taken place. Frozen partially baked chapatties after thawing and rebaking exhibited texture equivalent to that of conventionally baked chapatties therefore they could be considered a better option than frozen conventionally baked chapatties for retarding staling.     

EFFECT OF MINERAL FORTIFICATION ON RHEOLOGICAL PROPERTIES OF WHOLE WHEAT FLOUR

This study was aimed to evaluate the rheological changes that take place in the dough as a result of addition of elemental iron, ferric sodium ethylenediaminetetraacetate, zinc sulphate and zinc oxide in various combinations to whole wheat flour (WWF), packaged in polypropylene woven bags and tin boxes and stored for a period of 60 days under ambient and controlled conditions of temperature and relative humidity. Water absorption (WA) capacity, dough development time (DDT) and dough stability time (DS) of the fortified WWF were measured by farinographic method, and peak viscosity was assessed by viscographic analyses. WA capacity and DDT of flours increased during storage. Fortification significantly (P  <  0.05) affected WA, DDT, DS and viscographic characteristics of the flours. Packaging materials (P  <  0.05) influenced WA, DDT and DS, while storage condition had only affected viscographic properties of the flours.

PRACTICAL APPLICATIONS

The success of any fortification program depends on the stability of micronutrients and food to which they are added. Exposure of the fortificants to any of the physical and chemical factors including heat, moisture, air, or light and acid or alkaline environments during food processing, packaging, distribution or storage affects their stability. The rheological properties of dough made from fortified flours determine the quality of the fortified end product. Changes in rheological properties as a result of the incorporation of fortificants in the flour, its storage under variable conditions and length of time might have an effect on quality, cost and nutrition of the product.