Dynamic mechanical thermal analysis of chapati and phulka (Indian unleavened bread)

Glass transition temperature (Tg) and relaxation phenomena (α) of bread, chapati, phulka and phulka containing different anti-staling (A/S) additives such as glycerol, propylene glycol, maltodextrin, and anti-staling enzyme were determined using Dynamic Mechanical Thermal Analysis (DMTA). α-Transition which depends upon order of fall in modulus (FE¹), span (σ) and peak amplitude (A_t) of tan δ transition and Tg was drastically affected between bread and phulka, by incorporation of A/S agents in phulka and during its ageing (staling). During ageing Tg and A_t increased, whereas FE¹ and σ decreased. Phulka containing glycerol, propylene glycol and A/S enzyme gave satisfactory results.     

Staling of chapatti (Indian unleavened flat bread)

Staling in foods is a process, which occurs when starch chains after gelatinization begin to reassociate in an ordered structure. Staling of chapatti results in loss in texture and eating quality of chapatti. Moisture content, water-soluble starch, in vitro enzyme digestibility, enthalpy change (ΔH), texture and sensory quality of chapattis, which are significantly affected during staling both at room and refrigerated temperature storage, were monitored over a storage period of one month. Moisture content, water-soluble starch and in vitro enzyme digestibility were found to decrease steadily during staling of chapattis at both room temperature and refrigerated temperature of storage. Enthalpy change, ΔH, as measured by DSC increased with storage time. The texture of chapattis became progressively harder with storage at both room and refrigerated temperature. A decrease in sensory quality and acceptability of the chapattis was observed with storage. The rate of staling was lower at refrigerated temperature. Most of the staling parameters studied showed good correlation. Texture showed the best overall correlation with all other staling parameters. In general, the correlation obtained at room temperature was better than that at refrigerated temperature.     

Influence of whey protein concentrate on the rheological characteristics of dough, microstructure and quality of unleavened flat bread (parotta)

In order to explore the possibility of using WPC as a functional ingredient in Indian traditional product – South Indian Parotta investigations were made to study the effect of replacement of wheat flour with 5, 10 and 15% WPC on the farinograph, extensograph, amylograph characteristics of wheat flour, quality of parotta and microstructure of baked parotta. The results showed an increase in farinograph stability, extensograph resistance to extension up to 10% WPC and a decrease in the farinograph water absorption, extensograph extensibility, amylograph peak viscosity, cold paste viscosity, breakdown and setback values with an increase in the level of WPC from 0% to 15%. The quality characteristics of parotta showed that the spread ratio decreased and shear force values increased significantly above 5% level. Control parotta and parotta with 5% WPC were soft, possessed thin and transparent layers whereas parottas beyond 5% WPC had thick, fused and opaque layers. The parottas with 5% WPC were rated good. The quality characteristics of parotta were adversely affected beyond 5% level of WPC. The microstructure of the top and middle layer of baked parotta with 5% WPC showed that there was a disruption in the continuity of the gluten matrix.     

Carbohydrate composition of wheat,wheat bran,sorghum and bajra with good chapati/roti (Indian flat bread) making quality

Varieties of wheat, sorghum and bajra having good chapati/roti making quality were studied for carbohydrate profile. Polysaccharide fractions (water-soluble, barium hydroxide-soluble, alkali-soluble and insoluble) were isolated from these cereals and wheat bran and their carbohydrate profiles were studied. Arabinoxylans were the major polysaccharides, other than starch and cellulose. The ratio of arabinose to xylose in whole-wheat flour and wheat bran was nearly 1.25:1 but the hemicellulose A in wheat flour was mainly xylan-type. Among the pentosans in barium hydroxide extract of sorghum, the hemicellulose A had more arabinose than xylose, but the hemicellulose B contained nearly equal amounts of arabinose and xylose. Bajra had arabinose and xylose in nearly equal amounts in both the barium hydroxide extract and alkali-soluble fractions. The alkali-insoluble residues were complexes of pentosans with cellulose and were strongly bound. Contents of dietary fibre varied between the cereals. Wheat bran had the highest among the four.     

Effect of banana peel powder on bioactive constituents and microstructural quality of chapatti: unleavened Indian flat bread

Effect of banana peel powder (BPP) on the bioactive constituents and micro structural quality of chapatti was evaluated. Chapatti dough prepared from 5, 10, 15 and 20 % BPP was examined for dough stickiness, dough strength, dough kneading and rollability. With increased level of BPP, there was an increase in subjective score in kneading and rollability of chapatti. Dough stickiness was increased while increased dough strength was observed with increased level of BPP. Chapatti incorporated with BPP showed total phenolic content and flavonoid content significantly higher than the control. Chapatti incorporated with 20 % BPP showed DPPH radical scavenging activity up to 68.3 %. The tear force of chapatti prepared from dough added with 5, 10, 15 and 20 % BPP was 414, 404, 393, 356.2 g which was lower than that of control (449 g). The microstructure of chapatti prepared from dough added with 15 % BPP was uniform with solubilised starch granules while in the control starch granules were overlapping on one another to form aggregation. The X-ray diffraction pattern for chapatti incorporated with 15 % BPP showed V-type pattern. Chapatti’s prepared from BPP had softer chapatti and better pliability.     

Influence of enzymes on rheological,microstructure and quality characteristics of parotta—an unleavened Indian flat bread

Enzymes are used in the baking and milling industries to control dough properties and improve the quality of finished products. The role of enzymes in the baking process of an unleavened Indian flat bread, namely South Indian parotta, was studied. In this connection, comparisons have been made on the effects of different enzymes such as fungal α‐amylase (FA), glucose oxidase (GO), proteinase and xylanase on rheological characteristics and microstructure of parotta dough and its relation to the overall quality characteristics of baked parotta. Addition of GO increased, while FA, xylanase and proteinase decreased farinograph stability. Extensograph resistance to extension increased with GO or xylanase and decreased with FA or proteinase. The extensibility increased with FA, xylanase or proteinase and decreased with GO. The microstructure of parotta dough with different enzymes revealed that the use of proteinase improved the continuous gluten formation compared with the control and the other three enzymes, FA, xylanase and GO. This could be due to the proteinase enzyme breaking larger protein fibrils into smaller fibrils and thus enhancing the continuous gluten film formation. A similar observation was also noted in the microstructure of baked parotta layers. The microstructure of parotta with proteinase enzyme showed a continuous network of protein films compared with a cluster of protein films in parotta with GO. In the case of xylanase‐treated parotta, the starch granules were deformed completely and these deformed starch granules were found sticking to the protein films. In parottas prepared with GO and FA, only a few starch granules with faint outlines were visible. Generally speaking, the overall quality score of parotta decreased to 68 and 64 with the use of FA and, GO respectively, as against the control parotta score of 74. The score increased to 92 and 82 with the addition of proteinase and xylanase, respectively. Copyright © 2004 Society of Chemical Industry     

糙米挤压工程米生产工艺优化

以单因素试验为基础,采用自行研制的双螺杆挤压机和响应曲面试验设计方法,研究螺杆转速、水分含量、模头温度以及干燥温度等操作参数对糙米挤压工程米质构特性和复水率的影响,并对工艺参数进行优化。通过响应面分析得到最优工艺参数是螺杆转速为350 r·min-1,水分含量为31%,模头温度为75℃,干燥温度为65℃,其质构综合评分为75.6,复水率为82.8%,表明通过对生产工艺的优化,可改善糙米的口感和蒸煮特性,提高糙米的食用品质,因此具有潜在的工业化应用价值。     

杂粮面包的制备工艺优化研究

以燕麦粉、荞麦粉、玉米粉及糯米粉为复配杂粮原料,采用面包粉复配杂粮作面包,以面包的硬度和弹性为考核指标,比较了不同的发酵方法与烘烤方式对面包品质的影响,并对复配型杂粮面包的配方及工艺进行优化。结果表明:影响杂粮面包品质最主要的因素是和面时间,其次是发酵时间与烘烤时间。复配型杂粮面包中添加20%的白砂糖、1.2%的盐及2.4%的酵母,然后和面时间25min,发酵3.5h及烘烤20min时,杂粮面包的感官品质最好。此时,面包的硬度为5998.06g,弹性为0.886。产品质地柔软,色泽金黄,口感细腻并具有淡淡的杂粮风味。      

挤压碎米生产淀粉糖浆的工艺优化

以碎米为原料,糖化液DE值为考察指标,优化水料比、挤压机套筒温度、螺杆转速和进料速度等因素对挤压碎米生产淀粉糖工艺的影响.结果表明,相比于非挤压碎米,挤压碎米的液化液和糖化液还原糖含量显著增加;最佳的挤压工艺条件为套筒温度60℃,水与挤压碎米粉的质量比为12∶100,螺杆转速440 r/min,进料速度840 r/min;由方差分析可知,温度为极显著影响因子(P＜0.01).     

豆基杂粮米稀挤压膨化工艺优化

以豆渣为主要原料,复配杂粮及药食同源食材制备豆基杂粮米稀,以物料加水量、螺杆转速、Ⅲ区机筒温度为响应因素,糊化度为考察指标,在单因素试验的基础上,利用Design-Expert 8.0.6设计试验得到挤压膨化技术制备豆基杂粮米稀的最佳工艺条件。结果表明,在物料加水量12.5%、螺杆转速330 r/min、Ⅲ区机筒温度160 ℃的条件下,制备的豆基杂粮米稀具有较高的糊化度（91.47%）,冲调时口感细腻、香味浓郁、不易结块。     

富含挤压稳定化米糠粉面包的研制

研究了以挤压稳定化米糠粉为原料,生产面包的最适配方及技术条件。实验结果表明,添加10%的米糠粉可制得品质优良的面包。     

Fatty acids,mineral composition ond functional (bread and chapati) properties of high protein and high lysine barley lines

Six barley lines derived from corsses involving Hiproly (SV 73608×Mona⁵) and Riso 1508 with higher yield recipients V 43-42 and V 5681, along with the four parents, were analyzed for faty acids and mineral composition. Dough properties, bread and chapaties were charcterized by blending barley line (B82503) at 2.5-25% with bread wheat flour (pak 81). Fatty acid contents were myristic acid, 0.60-1.16%; palmitic acid, 16.68-20.84%; stearic acid, 1.30-3.33% and degree of unsaturation 1.40-1.50%. The derived lines contained similar amounts of essential fatty acids. Significant variation for magnesium, copper, zinc, phosphorus and potassium was observed but overlapped among the lines and parents. The calciu, iron, and manganese showed non-significant differences among lines and parents. Blending up to 10% barley flour with bread wheat flour gave farinograph characteristics comparable to those of pure wheat flour, but increasing the proportion of barley beyond this decreased the mix time and dough stability. Breadbaking tests verfied that up to 10% barley could be mixed with wheat without adversely affecting loaf volume and other quality attributes. For chapati making up to 20% barley could be blended into the wheat, yet yield acceptable quality.     

耐高糖面包酵母发酵工艺优化

为了优化耐高糖酵母发酵工艺,基于培养温度、摇床转速、装液量、初始p H、菌体接种量五个因素的单因素实验的结果,之后对装液量、初始p H、菌体接种量进行响应面优化实验。结果表明,最佳工艺条件为:培养温度30℃,摇床转速200 r/min,装液量8.4%,p H4.7,接种量7.4%,在此条件下,酵母细胞干重提高了55.72%。同时,利用5.0 L机械搅拌罐以溶氧反馈流加、恒速流加、间歇流加三种糖蜜补充方式进行酵母细胞培养,绘制生长曲线,发现以溶氧反馈流加方式补充糖蜜更有利于酵母繁殖,最大酵母湿重达到143.95 g/L,达到了耐高糖面包酵母高密度发酵的实验水平,确定了酵母最佳的流加补料方式。      

正交试验优化平菇面包工艺

以高筋小麦粉为主要原料,添加3种不同处理方式的平菇匀浆制作平菇面包。通过单因素和正交试验研究平菇处理方式、平菇添加量、白砂糖添加量、油脂添加量对面包品质的影响。结果表明:平菇面包最佳工艺参数为平菇蒸煮熟化匀浆处理,以高筋小麦粉质量(100%)为基准,添加12%平菇浆料、14%白砂糖、15%油脂、6%鸡蛋、2%食盐、2%酵母、3%面包改良剂、47%～48%水,在此条件下,平菇面包感官评分为90.5分。面包表皮有光泽,颜色均匀一致,面包芯质地细腻,填充物均匀分布,口感松软,除有面包特有的发酵香气外,后味香甜,有平菇香气。     

Rheological and nutritional studies of amaranth enriched wheat chapatti (Indian flat bread)

Chapatti made from whole wheat is a popular staple food in India. This article reports incorporation of amaranth (Amaranthus hypochondriacus) flour (20–50%) in wheat flour to get improved rolling properties and better nutrition in terms of proteins and micronutrients. Rheological studies of whole wheat flour (control) and amaranth–wheat combinations using farinograph revealed that amaranth flour (AF) addition up to 50% led to a decrease in percentage water absorption (84.80–77.55%) and dough stability (1.6–0.6 min). Stickiness of dough slightly increased (31.2–33.55 g), but there was overall improvement in softness, rollability, and spreadability of dough with increasing levels of AF. Based on texturometer measurement and sensory evaluation of chapattis, incorporation of 40% AF is recommended. Chapatti made from this blend had significantly higher content of ash (iron, calcium, and magnesium), fat, protein, and lysine; it also showed improved in vitro protein digestibility.

Practical applications

In recent times, pseudo‐cereals such as amaranth, quinoa, and buckwheat, which were hitherto not consumed popularly, have attracted the attention of consumers all over the world due to their nutritional profile. Amaranth is a hardy crop which grows vigorously even in drought conditions. It is a rich source of protein, fat, fiber, and minerals. It has a balanced amino acid profile and is particularly rich in lysine. However, its consumption in India is limited to a few traditional products and it has remained largely underutilized. Staple foods like wheat chapatti can be supplemented with amaranth flour for nutritional improvement of the product. An understanding of the influence of AF on dough functionality and chapatti quality would be beneficial from the point of view of product development. This study investigated the effect of AF incorporation on rheological, nutritional, and quality characteristics of chapatti.     

响应面法优化富硒番薯面包的工艺

为了弥补部分人群硒摄入不足,将富硒番薯粉添加到面包中,为消费者提供一种新型的、具有保健功能的面包。通过单因素试验,响应面试验对面包的生产工艺进行优化,得到富硒番薯面包最佳配方:富硒番薯粉添加量8.51%、酵母粉添加量0.86%、蔗糖添加量5.94%,在此条件下富硒番薯面包的感官评分91.2分。     

Optimization of ingredients and baking process for improved wholemeal oat bread quality

Baking technology for tasty bread with high wholemeal oat content and good texture was developed. Bread was baked with a straight baking process using whole grain oat (51/100 g flour) and white wheat (49/100 g four). The effects of gluten and water content, dough mixing time, proofing temperature and time, and baking conditions on bread quality were investigated using response surface methodology with a central composite design. Response variables measured were specific volume, instrumental crumb hardness, and sensory texture, mouthfeel, and flavour. The concentration and molecular weight distribution of β-glucan were analysed both from the flours and the bread. Light microscopy was used to locate β-glucan in the bread. Proofing conditions, gluten, and water content had a major effect on specific volume and hardness of the oat bread. The sensory crumb properties were mainly affected by ingredients, whereas processing conditions exhibited their main effects on crust properties and richness of the crumb flavour. β-glucan content of oat bread was 1.3/100 g bread. The proportion of the highest molecular weight fraction of β-glucan was decreased as compared with the original β-glucan content of oat/wheat flour. A great part of β-glucan in bread was located in the large bran pieces.     

响应面法优化冷冻面团馒头冷冻工艺

为确定冷冻面团馒头最佳冷冻工艺参数,在单因素试验基础上,选择冷冻时间,冷冻温度为自变量,馒头感官评分、馒头比容、馒头硬度为响应值,利用Box-Benhnken中心组合试验和响应面分析法,研究各自变量及其交互作用对冷冻面团馒头感官评分、比容、硬度的影响。通过回归分析和响应面曲面图,得到最优工艺参数并进行验证试验。结果表明,冷冻温度为-30℃,冷冻时间为30 min时,馒头感官评分(85.2分)、比容(2.45 cm3/g)及硬度(485.47 g/kg)均达到最佳值。     

Effect of extruded wheat bran on dough rheology and bread quality

Bran extrusion is mainly under study and works should be performed to know the effect on dough and bread. This study was designed to investigate the effect of bran extrusion (addition of 2.5 g/100 g to 20 g/100g bran) on the rheological characteristics of bread dough, behaviour during fermentation, and bread quality. Extruded bran increased dough development time and tenacity to a greater extent than non-extruded bran, and minimized the loss of stability if over-mixing occurred. Extruded bran, due to its greater gas production, also reduced loss of dough height during fermentation to a greater extent than untreated bran. However, breads with extruded bran showed a higher volume and lower initial firmness than breads with normal bran if improver was added. However, no differences were found in the organoleptic evaluation. Bran extrusion therefore modified dough rheology but did not negatively affect bread quality. It could even improve the quality of breads with bran when improvers are added.     

Optimization of sourdough process for improved sensory profile and texture of wheat bread

The aim of the study was to determine optimum sourdough process conditions for improved flavour and texture of wheat bread. The influence of process conditions and the starter culture on the characteristics of wheat sourdough bread was established by using response surface methodology. Influence of fermentation temperature (16-32 °C), ash content of flour (0.6-1.8 g/100 g), and fermentation time (6-20 h) were considered as independent factors and their effects were studied in sourdough bread fermented with Lactobacillus plantarum, Lactobacillus brevis, Saccharomyces cerevisiae or with a combination of yeast and lactic acid bacteria. Intensity of sensory attributes, specific volume and bread hardness were considered as the main responses. Ash content of flour and fermentation time were the main factors determining the intensity of sensory attributes. The possibility to enhance intensity of overall flavour, aftertaste and roasted flavour without excessive pungent flavour and without reduced fresh flavour in wheat bread containing 20 g sourdough/100 g of wheat dough was demonstrated by choosing e.g. Lb. brevis for a starter and by utilization of high ash content of flour, long fermentation time and reduced temperature. Bread specific volume was improved 0.2-0.5 ml/g and hardness was reduced (after 4 days of storage) up to 260 g by using low ash content of flour and by optimizing fermentation time according to the microbial strain. Lactic acid fermentation had more profound influence on both desired and undesired flavour attributes, as well as textural features of bread in comparison with yeast fermentation.