Impact of endogenous constituents from different flour milling streams on dough rheology and semi-sweet biscuit making potential by partial substitution of a commercial soft wheat flour

A flour fractionation-reconstitution procedure was used to study the substitution of a commercial soft wheat flour with gluten, water extractables, prime starch and starch tailing fractions isolated from patent and clear flour streams on dough rheology and semi-sweet biscuit characteristics. Substitution of soft wheat flour with increasing levels of the native patent and clear flour streams raised the dough consistency, hardness and elastic properties as well as the biscuit textural attributes (density, hardness). The dough stickiness of the base flour was also reduced and the biscuits were free of cracks. Gluten isolated from the patent flour had a greater impact on dough consistency, hardness and elastic properties than gluten obtained from the clear flour, likely due to the superior protein quality of the former. Additionally, with increasing gluten levels in the fortified flour there were moderate increases in biscuit density, hardness, and lower crunchiness. The addition of starch tailings produced the largest impact on consistency and hardness of the dough. This fraction also exerted a pronounced effect on biscuit density and hardness, while it lowered crunchiness, presumably due to its higher pentosan content. Overall, the dough rheological properties and biscuit characteristics were controlled by the amount-nature of the fractions added; i.e., besides gluten (amount and quality), other constituents such as pentosans and the overall composition of the flour blends can largely affect the quality of the semi-sweet biscuits.     

不同淀粉对饼干口感润滑质地的影响

目的 探究不同植物源淀粉对饼干口感润滑质地的影响规律。方法 以不同植物源淀粉和面粉进行配比加入配料研制不同植物源淀粉饼干,结合流变学、感官评价、摩擦学参数考察其对饼干质地、口腔润滑及感官属性的影响。结果 不同淀粉饼干的润滑性结果为:马铃薯淀粉饼干>豌豆淀粉、红薯淀粉饼干>绿豆淀粉饼干,其结果与感官差异分析结果一致。结论 淀粉作为润滑质地调节剂,可以提高饼干产品口腔润滑性能,同时该研究也为口腔摩擦学用于主观感官分析提供参考。     

Evaluation of Starch Degradation and Textural Characteristics of Dietary Fiber Enriched Biscuits

Abstract

The effects of dietary fiber inclusion on biscuit texture, cooking properties, and sugar release after in vitro degradation were investigated. Inulin, β-glucan enriched fraction (BGEF), potato fiber, and a resistant starch were used. Effects of the dietary fibers on the pasting properties of flour based mixtures were investigated using a rapid visco analyzer. Results showed a reduction in visco-pasting properties (peak viscosity and final viscosity) of the flour–dietary fiber systems with increasing fiber content. Addition of dietary fiber into the biscuits affected biscuit shrinkage and height development during cooking, as well as generally reducing the resistance of biscuits to snapping during texture analysis tests. Sugar release during in vitro degradation studies showed a highly significant decline when comparing dietary fiber enriched biscuits to the control samples. This would have a beneficial effect in potentially reducing the glycaemic index and subsequent glycaemic loading of such foods.     

麦麸对酥性饼干物理性质和淀粉消化性的影响

目的 研究麦麸对酥性饼干颜色、物理性质以及淀粉消化性的影响。方法 将麦麸按0～50%比例添加到面粉中制作饼干,测定混合粉的溶剂保持力,测定饼干颜色、延展度、硬度以及淀粉消化性。结果 添加麦麸导致混合粉的水和碳酸钠溶剂保持力值增加,乳酸溶剂保持力值和面筋性能指数降低(4.71%～33.20%和25.73%～34.11%),饼干颜色变暗。当麦麸添加量大于20%时,饼干的延展度和硬度增大(53.54%～64.31%和135.98%～408.53%)。此外,麦麸的添加在一定程度上降低了饼干淀粉消化性。麦麸添加量与饼干物理性质呈强正相关性,与消化终点葡萄糖含量呈负相关。通过主成分分析,提取了2个主成分,累计方差贡献率为85.3%。结论 适量添加麦麸有效改善了饼干酥脆性,并在一定程度上抑制了饼干淀粉的消化,增加了饼干的功能性质,可以为麦麸产品的进一步开发提供参考。     

Physicochemical properties of commercial semi-sweet biscuit

This study was performed to provide information about the physical and chemical characteristics of commercial semi-sweet biscuits and to ascertain the key characteristics of commercial semi-sweet biscuits (rich tea type), in terms of starch properties, such as gelatinisation, pasting, granule crystallinity and morphology, and to compare the magnitudes of changes of physical characteristics (diameter, thickness, weight and bulk density) for selected brands. A total of 10 rich tea biscuits from different brands were bought locally and were measured for physical and chemical characteristics. The three-point bend test showed that a biscuit with lower fat content was harder than a biscuit with normal fat content, except for sample B. Starch gelatinisation properties show that To, Tp and Tc were higher than for wheat flour whereas ΔH was lower than for wheat flour. X-ray results showed that commercial biscuits still retained their crystallinity but at lower intensities than native wheat flour. Microscopy observations revealed that some of the granule birefringence of commercial biscuits can still be observed under polarised light. Different brands of biscuits showed different physical and chemical characteristics.     

马铃薯抗性淀粉对韧性饼干品质及消化性能的控制

目的 研究马铃薯抗性淀粉对韧性饼干消化性能及品质的影响规律, 为评价和提高马铃薯抗性淀粉韧性饼干的品质奠定基础。方法 通过将马铃薯抗性淀粉作为膳食纤维成分, 按照不同比例替代面粉, 制作成韧性饼干, 对韧性饼干的延展性、色泽、感官、质构特性、表观结构等物理特性、营养成分及消化性能进行测定, 研究马铃薯抗性淀粉对韧性饼干品质及消化性能的影响。结果 随着马铃薯抗性淀粉的增加, 韧性饼干的延展性总体呈增长趋势,蛋白质和脂肪含量逐渐减少,水分和灰分含量差异不显著。在马铃薯抗性淀粉添加为20%时饼干色泽均匀,硬度、脆性和咀嚼性均较好, 感官评分最高, 为82.6分。SEM观察发现随着马铃薯抗性淀粉的添加饼干结构显示暴露在油脂外的淀粉颗粒逐渐增加。马铃薯抗性淀粉的加入降低系统中淀粉的水解速率, 进而调节饼干的体外消化率, 降低血糖指数, 添加30%马铃薯抗性淀粉时, 血糖指数为62.06, 已达到中等血糖指数。结论 适量的马铃薯抗性淀粉添加到韧性饼干中可以改善饼干品质, 随着马铃薯抗性淀粉含量的增加, 饼干血糖指数降低。为抗性淀粉饼干的开发提供理论基础。     

Quality evaluation of biscuits produced from composite blends of pumpkin seed oil press cake and wheat flour

Pumpkin seed oil press cake (PSOPC) is a by-product of pumpkin oil production, and after cold pressing, a significant amount of oil still remains in the press cake. The aim of this study was to investigate the possible use of PSOPC flour as a substitute for wheat flour in biscuit production and, consequently, for reducing shortening usage. Biscuits have been produced from composite blends of plain white flour and PSOPC flour in ratios 100:0, 80:20, 60:40 and 40:60, respectively. Shortening addition was gradually reduced depending on the PSOPC flour addition. Biscuit baking quality was determined by width, thickness, spread factor, volume and textural properties. Computer vision was used to evaluate biscuit colour, and sensory evaluation was conducted for colour, taste, texture and overall acceptance. Results showed that PSOPC flour decreased biscuit diameter, height and volume and also caused a softer texture of biscuit. PSOPC flour contributed to the greenish colour of biscuits and the pleasant taste of roasted pumpkin seed. PSOPC flour can be successfully used as a functional and nutritionally valuable substitute for wheat flour and shortening, even in quantities up to 60%, without significant deterioration of the technological quality of biscuits.     

红薯泥饼干的研制

将红薯制成红薯泥,并以此为原材料加工红薯食品,可提高红薯食品的食用价值。通过正交试验确定产品的最佳配方为：红薯泥300 g∶低筋面粉300 g∶糖100 g∶猪油140 g。通过测定红薯泥饼干的理化指标,证明红薯泥制品抗氧化物总量多于普通饼干,更对人体健康有益。     

Biscuit making properties of flours from hard and soft milling single variety wheats

Bench scale baking tests for two types of biscuits,¹ a hard sweet (HS) and a short sweet (SS), have been used to examine the biscuit making properties of a large number of flour samples from wheats grown in four consecutive years (1980–1983). Multiple regression models for prediction of biscuit properties using a range of standard cereal laboratory tests as independent variables on results from 1980–1981 harvest wheats confirmed earlier observations that such tests are of limited commercial value for biscuit flour specification. However the results of baking tests, with both types of biscuit, from single wheat varieties grown during 1981–1983 showed that flours from soft milling wheats (SMW) required less water to give biscuit doughs of standard consistency (measured instrumentally) than did flours from hard milling wheats (HMW). In addition biscuit doughs made with SMW flours gave greater oven spring, i.e. biscuits of lower bulk density, than doughs made from HMW flours. In each season the difference in the mean values of both parameters for flours milled from SMW and HMW was highly significant (P<0.001). With one exception the variability of the measured parameters within seasons was not significantly different between SMW and HMW. However within both SMW and HMW varieties highly significant differences (P<0.001) were observed between seasons for the mean values of both measured biscuit parameters. The effect of flour particle size on the biscuits was studied by regrinding a number of flours. With flours from both SMW and HMW reduction in particle size resulted in HS biscuits of higher density but SS biscuits of lower density.     

Physicochemical, pasting and thermal properties of tuber starches as modified by guar gum and locust bean gum

This study was carried out in order to compare the functional characteristics of isolated starch from five tuber crops, yam, taro, sweet potato, yam bean and potato, as well as effect of guar gum (GG) and locust bean gum (LBG) on pasting and thermal properties of tuber starches. The results showed that total amylose content of five tested starches ranged from 17.85% to 30.36%. The results of pasting behaviour showed that potato starches exhibited the highest peak viscosity and yam starch presented a stable curve with little breakdown viscosity. Addition of GG and LBG resulted in a significant increase in peak, final viscosity, breakdown and setback viscosity for all tuber starches ( P  < 0.05), but a slight decrease in pasting temperature. The gelatinisation enthalpy (Δ H ) for starches with GG and LBG was slightly lower than those of the starches alone in yam and sweet potato, but not in taro and yam bean.     

远红外线烘烤制作甘薯酥脆饼干的工艺探讨

以鲜甘薯为主要原料,应用正交实验和远红外线烘烤技术探讨了制作甘薯酥脆饼干的工艺及参数,同时研究了常用辅料对烘烤甘薯酥脆饼干质构的影响。甘薯酥脆饼干的配方为:水分50%的熟甘薯100%,小麦面粉30%,马铃薯淀粉5%,木薯淀粉6%,玉米淀粉5%,NaHCO30.2%,NH4HCO30.2%;在配料中加入轻化油5%,全脂奶粉5%,人造奶油3%,鸡蛋2%,可强化甘薯酥脆饼干的酥松度和外观的质量;远红外线烘烤参数为:第一阶段烘烤温度95℃、时间70 min,第二阶段烘烤温度105℃、时间5 min。     

Effects of mucilage on the thermal and pasting properties of yam, taro, and sweet potato starches

This study investigates the effects of water-soluble mucilages (0, 2.5, and 5 g/100 g; w/w, dry basis) on the thermal and pasting properties of isolated starches from three root and tuber crops. The results show that yam tuber presents the greatest level of mucilage and also possess the largest amylose content of the three isolated starches. The addition of mucilage caused a remarkable increase in the temperature of gelatinization for the three tested starches due to the competition for water during starch gelatinization. Furthermore, adding mucilage increased the phase transition temperature range (Tc-To) of starches but decreased enthalpy (ΔH). However, although the pasting temperature increased with the addition of mucilage into tuber starches, it did not change that of taro starch. The peak viscosity of taro and sweet potato starches decreased significantly as their mucilages were added into each starch suspension system (p < 0.05). However, the addition of mucilage slightly increased the viscosity of yam starch. Furthermore, the addition of mucilage slightly increased the swelling power of yam and taro starches, but did not change that of sweet potato starch.     

红薯泥饼干的研制

为了能更好地保存红薯中的大部分营养素,并保持原有口感风味,将红薯制成红薯泥,并以此为原辅料加工为红薯食品,以提高红薯的食用价值。通过正交试验确定产品的最佳配方为:红薯泥∶低筋面粉∶糖∶猪油为3∶3∶1∶1.4。通过测定红薯泥及红薯泥饼干的理化指标,证明了红薯泥及红薯制品对人身体具有很大益处。     

挤压膨化紫薯粉对小麦面团糊化特性和热机械学特性的影响

挤压膨化技术是一种高温、短时的加工方法,可以改变紫薯粉的特性,从而提高复合面团的品质。因此,本实验对紫薯粉进行挤压膨化,对比研究挤压膨化紫薯粉和紫薯生粉对小麦面团水分分布、糊化特性及热机械学特性的影响。结果发现,与紫薯生粉相比,挤压膨化紫薯粉显著缩短了横向弛豫时间T21（P＜0.05）,表明挤压膨化能够使水分与淀粉或面筋蛋白紧密结合;此外,与小麦粉相比,添加紫薯粉显著降低了面团的峰值黏度、谷值黏度、终点黏度、崩解值和回生值（P＜0.05）,尤其是挤压膨化紫薯粉。热机械学特性结果表明挤压膨化紫薯粉能够显著提高面团的吸水率、酶解速率和蒸煮稳定性（P＜0.05）,缩短面团形成时间,降低回生值和峰值扭矩（P＜0.05）。挤压膨化紫薯粉的添加不仅可以提高面制品的出品率,也有助于延缓面团的老化,延长保质期。本研究为挤压膨化紫薯粉在面制品中的应用提供了一定的理论依据。     

Effect of native and germinated finger millet flour on rheological and sensory characteristics of biscuits

Wheat flour was replaced with native finger millet flour (NFMF) and germinated finger millet flour (GFMF) at 30–50% levels to make soft dough biscuits. Dough rheological properties and baking characteristics of the blends were evaluated. Farinograph data of wheat flour replaced with NFMF and GFMF showed a decrease in water absorption, dough stability and an increase in mixing tolerance index as the level of replacement increased. Extensibility of dough decreased for both NFMF and GFMF as the levels increased. The hardness of biscuit dough measured by texture profile analysis increased from 125 to 234 N for NFMF and 118 to 126 N for GFMF. Scanning electron microscopic studies on the biscuit dough showed polygonal finger millet starch granules adhering to wheat starch granules and protein matrix. The results of the study indicated that the replacement level of 40% with either NFMF or GFMF produced biscuits with acceptable sensory attributes. Addition of sodium stearoyl‐2‐lactylate (SSL) showed further improvement in terms of spread ratio, surface characteristics and texture.     

The Use of Potato and Sweet Potato Starches Affects White Salted Noodle Quality

ABSTRACT Potato and sweet potato starches and derivatives thereof were used to substitute part of the wheat flour in white salted noodle (WSN) manufacture. The quality of the WSN obtained was compared with the quality of WSN made from wheat flour only. When up to 20% of wheat flour was replaced by acetylated potato starch and acetylated sweet potato starches, the cooking loss of WSN decreased, while the softness, stretchability, and slipperiness increased significantly. Native and hydroxypropylated starches did not exhibit these effects. It can be concluded that the substitution of part of wheat flour with acetylated starches strongly affects noodle-making and final noodle quality, and starch substitution can be used to change the performance of a given wheat flour for noodle making in a desired way.     

鱼糜和马铃薯粉对饼干质构和风味的影响

采用质构分析、电子鼻与固相微萃取-气相色谱-质谱联用方法,对制备的鱼糜马铃薯饼干质构和风味进行对比分析。以感官评定和质构为评价指标,以低筋面粉含量为100%,确定鱼糜马铃薯饼干的配方为:马铃薯全粉相对含量30%、马铃薯淀粉相对含量20%、鱼糜相对含量40%、棕榈油相对含量40%。对鱼糜马铃薯饼干、鱼糜饼干、马铃薯全粉饼干和普通饼干的风味进行对比,结果发现4种饼干的风味物质主要为杂环类、烃类和醛类化合物,其中以美拉德反应产物甲基吡嗪和2,5-二甲基吡嗪为主,含有鱼糜的饼干中,醛类化合物的种类和含量明显增加。本研究为饼干的香气特征研究提供科学依据,为马铃薯和鱼糜的开发利用提供一定参考。     

Influence of gluten-free flour mixes and fat powders on the quality of gluten-free biscuits

Studies were conducted to develop gluten-free biscuits comparable in quality to wheat (W) biscuits and superior to those made from commercial gluten-free flour (Gf), suitable for coeliac sufferers. Three mixes of brown rice flour (R), corn starch (C), potato starch (P), soya flour (S), buckwheat flour (B) and millet flakes (M) were studied: RCPS in the percentage 70, 10, 10, 10, RPBM (50, 30, 10, 10) and RCPM (25, 25, 25, 25). Biscuits were tested for water activity, moisture, texture (snap test), diameter, thickness and colour (L* value), biscuit dough for hardness and stickiness. Various correlations >0.8 indicated for the three mixes, W and Gf that firm, non-sticky doughs yielded firm, thin, non-oval biscuits. Cluster analysis revealed that RCPS was most similar to W with regards to all parameters measured, and RCPS also showed best overall acceptability in sensory testing. Three fat powders were studied for use instead of palm oil: high and low fat dairy powder (HFP, LFP) and microencapsulated high fat powder based on vegetable fat (ME). HFP and ME yielded biscuits of comparable texture to palm oil, LFP resulted in much firmer biscuits, attributed to lower fat and higher protein and total sugar content.     

山药粉对面团特性和韧性饼干品质的影响

为研究山药粉添加量对面团特性和饼干营养品质的影响,本文分析不同山药粉添加量对面团粉质特性、糊化特性、质构特性、面筋含量及韧性饼干感官品质的影响,同时评价最佳工艺条件下饼干的营养品质。结果表明,随着山药粉添加量的持续加大,面团形成时间、稳定时间、衰减值、面团弹性及饼干感官质量先增加后降低,面团弱化度持续削减,最低粘度、峰值粘度和最终粘度及回生值呈现持续增加。当山药粉添加量为20%时,韧性饼干的口感较好,带有山药风味。与普通韧性饼干相比,脂肪含量和快速消化淀粉含量分别显著降低12%和23%(P<0.05),蛋白质、黄酮、慢速消化淀粉和抗性淀粉含量分别增加15%、33%、11%和22%(P<0.05)。山药韧性饼干符合现代饼干市场需求。     

蒸汽爆破甘薯渣粉对小麦粉粉质及饼干品质特性的影响

研究蒸汽爆破甘薯渣粉对小麦粉粉质及混合粉制作饼干品质特性的影响。将蒸汽爆破甘薯渣粉添加到小麦粉中,测定不同比例蒸汽爆破甘薯渣粉与小麦粉混合后的沉淀指数、糊化特性、粉质特性以及混合粉饼干质构性质。结果表明：小麦粉中添加不同量的蒸汽爆破甘薯渣粉后,小麦混合粉的沉淀指数、峰值黏度、低谷黏度、稀懈值、最终黏度和反弹值均降低;蒸汽爆破甘薯渣粉添加到小麦粉中,面筋蛋白被稀释,吸水能力随可溶性膳食纤维质量分数的增加而增加,而面团的形成时间和稳定时间缩短,弱化度升高,粉质质量指数降低;混合粉焙烤出的饼干质构特性发生变化。根据饼干的质构特性和感官评定结果,在低筋面粉中添加质量分数6%的蒸汽爆破甘薯渣粉时,混合粉制作的饼干品质最佳。