Effect of inulin soluble dietary fibre addition on technological, sensory, and structural properties of durum wheat spaghetti

Investigation of two inulins with differing degrees of polymerisation and crystallinity demonstrated different levels of integration with the starch-gluten matrix during pasta preparation. The impact of higher molecular weight inulin incorporation on technological and sensory properties was minimal, with deterioration in properties becoming significant only at 20% incorporation, while lower molecular weight had a greater negative impact on pasta firmness, cooking loss, and sensory acceptability. In vitro starch digestion of pasta was reduced with up to 5% addition of inulin of degree of polymerisation 12-14 (FH-D), but increased with high levels of addition. These effects were not observed in inulin with a degree of polymerisation of 7-8 (LV-100). Microscopy showed the starch granules were apparently encapsulated by a protective coat of inulin FH-D, but at 20% a disruption to the matrix was evident. For inulin FH-D, XRD analysis of digested pasta found a maximum crystallinity which coincided with the maximum reduction in starch hydrolysis, suggesting that a stronger gluten matrix enhanced by added inulin is indeed structurally different at the nanometre level.     

Effects of particle size on physiochemical and in vitro digestion properties of durum wheat bran

In order to promote the potential health benefits of high fibre products, wheat bran is the main focus of the food industry. The physiochemical and in vitro digestion properties of wheat bran containing different particle size were investigated and compared against raw bran samples. Firstly, the bran sample containing superfine particles (11.63 μm) was hydrolyzed by the α-amylase, pepsin, and pancreatin enzymes separately using a single factor and orthogonal test. Secondly, optimized hydrolysis parameters of superfine particles were employed to measure in vitro digestibility of macronutrients in raw, coarse, medium, and superfine bran particles. The maximum degree of hydrolysis obtained via α-Amylase (concentration 10 mg mL⁻¹, pH 6.6, and time 12.5 min) was 55.71%; pepsin (concentration 50 mg mL⁻¹, pH 1.2, and time 9 h) was 82.10%; and pancreatin (concentration 100 mg mL⁻¹, pH 7.0 and time 12 h) was 84.71%, respectively. The highest in vitro digestibility rate of reducing sugar, protein, fat, and soluble fibre content was observed in superfine bran samples to 33.4%, 82.55%, 91.53%, and 21.66%, respectively.     

Effect of soluble fibre (guar gum and carboxymethylcellulose) addition on technological, sensory and structural properties of durum wheat spaghetti

Incorporation in pasta of either of two soluble fibres, carboxymethylcellulose sodium salt (CMC) and guar gum (GG), was found to significantly reduce the rate of invitro starch digestion. The amount of reducing sugars produced over 300 min was reduced by 18% at 1.5% CMC incorporation and 24% at 20% GG incorporation. Negative effects on sensory and technological properties were seen at the high levels of GG needed to reduce the rate of in vitro digestion, and a ‘matty’ layer covering the surfaces of starch granules was observed by scanning electron microscopy and confocal scanning laser microscopy. By contrast, levels of CMC incorporation giving large reductions in in vitro digestion had no negative effects on pasta properties. No significant alteration in pasta structure on CMC incorporation was observed by microscopy. The large difference in the amounts of soluble fibre required to bring about equivalent reductions in digestion rate suggests that different mechanisms may be involved in the two cases.     

小麦抗性淀粉物理性质研究

采用微波—酶法制备小麦抗性淀粉,用扫描电子显微镜(SEM)观察小麦抗性淀粉颗粒结构,用X-射线衍射仪测定其结晶结构,并测定抗性淀粉持水性、乳化性、粘度等物理特性。研究结果表明,与原小麦淀粉相比,小麦抗性淀粉表面粗糙,形状变得不规则,结晶结构为B型和V型结合体,持水性大于原淀粉,而乳化能力和乳化稳定性均低于原淀粉;在相同溶液浓度条件下,抗性淀粉粘度比原淀粉低得多。     

Optimisation of resistant starch II and III levels in durum wheat pasta to reduce in vitro digestibility while maintaining processing and sensory characteristics

Foods with elevated levels of resistant starch (RS) may have beneficial effects on human health. Pasta was enriched with commercial resistant starches (RSII, Hi Maize™ 1043; RSIII, Novelose 330™) at 10%, 20% and 50% substitution of semolina for RSII and 10% and 20% for RSIII and compared with pasta made from 100% durum wheat semolina to investigate technological, sensory, in vitro starch digestibility and structural properties. The resultant RS content of pasta increased from 1.9% to ∼21% and was not reduced on cooking. Significantly, the results indicate that 10% and 20% RSII and RSIII substitution of semolina had no significant effects on pasta cooking loss, texture and sensory properties, with only a minimal reduction in pasta yellowness. Both RS types lowered the extent of in vitro starch hydrolysis compared to that of control pasta. X-ray diffraction and small-angle scattering verified the incorporation of RS and, compared to the control sample, identified enhanced crystallinity and a changed molecular arrangement following digestion. These results can be contrasted with the negative impact on pasta resulting from substitution with equivalent amounts of more traditional dietary fibre such as bran. The study suggests that these RS-containing formulations may be ideal sources for the preparation of pasta with reduced starch digestibility.     

Amylose content and starch properties in emmer and durum wheat lines with different waxy proteins composition

BACKGROUND: Emmer wheat is a neglected crop that can be used in the breeding of modern durum wheat for quality. One important aspect of this quality is the starch composition, which is related to the waxy proteins. A collection of emmer wheat was analysed previously for waxy protein composition, and two new Wx‐B1 alleles were found by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and DNA sequencing analysis. It is necessary to analyse the effect of these alleles in starch properties and compare them to durum wheat ones. RESULTS: In the current study, emmer lines carrying three different Wx‐B1 alleles (Wx‐B1b, ‐B1g, ‐B1c*), including one with the null allele (Wx‐B1b), together with durum cultivars Langdon (Wx‐B1a) and Mexicali (Wx‐B1c′), were analysed for amylose content. Differences were detected between both species, and the line lacking Wx‐B1 protein showed a remarkably low amylose content. In addition, data from blue value, swelling power and Rapid Visco Analyzer also suggested that there were differences in starch properties among the different Wx‐B1 alleles. CONCLUSION: The present study suggests that the amylose content in emmer (Wx‐B1g) and durum (Wx‐B1a) standard materials is not the same; therefore some starch properties are different between the two species. The variation found could be used to enlarge the gene pool of durum wheat and design new materials with desirable amylose content. Copyright © 2011 Society of Chemical Industry     

Furosine and flavour compounds in durum wheat pasta produced under different manufacturing conditions: Multivariate chemometric characterization

The headspace solid-phase microextraction (HS-SPME) technique followed by GC/MS analysis was performed to evaluate the volatile fraction of durum wheat pasta produced under different process conditions (artisan manufacturing methods or industrial processes). At the same time, HPLC analysis was performed to quantify furosine in the same pasta samples. Furosine is commonly used as an index of nutritional damage occurring during pasta drying, although drastic thermal treatments may lead to its underestimation. Moreover, since furosine determination requires time/solvent-consuming methods, a more convenient approach could be the identification of volatile compounds formed during the drying step and detectable through simple and automated methods. Principal Component Analysis (PCA) was applied to experimental data in order to discriminate pasta samples according to their drying conditions. A limited number of volatile compounds including Maillard reaction and lipid-derived products (nonanal, hexanal, nonanoic acid, maltol and 2-furanmethanol) proved to be crucial in the differentiation of the samples. Therefore, these compounds could be used as pasta quality markers, alternatively to furosine, or as process markers to keep the drying treatment under control.     

湿热处理对小麦淀粉结构和性质影响

对小麦淀粉进行湿热处理,研究不同初始含水量对小麦淀粉结构和性能影响。实验结果表明,经湿热处理后小麦淀粉颗粒表面出现凹坑,随初始水分含量增加,淀粉颗粒表面凹坑数量增加,同时粘结现象变得严重;湿热处理小麦淀粉糊化温度随初始含水量增加而升高;经湿热处理后小麦淀粉对酸和酶敏感性增加,更易被酸和酶水解。     

发芽对小麦淀粉结构和性质的影响

主要研究了发芽对小麦淀粉的结构和性质的影响.从未发芽和发芽6、12、18、24、30 h的小麦中提取淀粉,用扫描电子显微镜来观察未发芽和发芽后的小麦淀粉的结构变化,并分析淀粉糊的透明度、凝沉性质、冻融稳定性以及淀粉颗粒的溶解度和膨胀度等变化.结果表明,发芽小麦淀粉中的B型淀粉的数量比发芽前有所增加,且部分A型淀粉的结构随发芽时间的增加结构遭到破坏.未发芽的小麦淀粉的黏度和透明度都高于发芽后的,而发芽后的小麦淀粉的水分、吸水率、溶解率、膨胀势和冻融稳定性都高于未发芽的.酸水解过程的前5d,发芽处理淀粉水解率比原淀粉小,之后水解率大于原小麦淀粉.     

魔芋胶对小麦淀粉理化性质影响研究

以小麦淀粉为原料,研究不同添加量魔芋胶对小麦淀粉糊化特性、质构性、冻融稳定性和消化性影响。结果表明:随魔芋胶添加量增加,小麦淀粉粘度呈上升趋势;添加魔芋胶后淀粉凝胶冻融稳定性提高,硬度降低;且小麦淀粉快速消化淀粉含量明显降低,而慢速消化淀粉含量明显升高。     

Effect of insoluble dietary fibre addition on technological,sensory, and structural properties of durum wheat spaghetti

Insoluble fibres are important in human health and disease prevention and can be incorporated into food. High fibre pasta prepared with bran is typically inferior quality compared to durum pasta. This study compared spaghetti prepared from durum semolina substituted with various amounts of either durum bran or germ (pollard) dried at high temperature. Pasta was evaluated for cooking properties, texture, sensory, fibre content, antioxidant status (AO) and in vitro starch digestibility to determine the dose producing acceptable quality. Pollard at 10% substitution had minimal impact on quality with higher AO and fibre. Above 30%, pasta had undesirable colour, sensory properties and higher starch digestion. Although bran substituted pasta had undesirable sensory and technological properties, especially at 30% incorporation, it does provide more dietary fibre and antioxidants than regular pasta and does not affect starch digestibility. Interestingly, a significant amount of AO was retained in the cooked pasta. The study illustrates the value of structural analysis to explain observed technological properties of the product with fibre inclusion.     

乳化剂对糯小麦淀粉老化特性的影响

老化对淀粉的生理效价和生物降解具有决定性作用,糊化淀粉在存放过程中,淀粉分子发生自组,其直链淀粉及支链淀粉的直线部分趋向于平行排列,从无定形态回复到晶体态,出现老化现象,会导致淀粉基生物材料产品的品质和性能大幅降低。本课题对直链淀粉含量、水分含量及乳化剂种类对糯质小麦淀粉老化特性的影响进行研究,比较乳化剂对糯质小麦淀粉及普通小麦淀粉老化特性影响的异同。结果表明:直链淀粉的含量、水分含量都与糊化淀粉的老化程度呈正相关。直链淀粉的含量是决定淀粉老化程度的最主要因素,乳化剂与淀粉分子相互作用形成稳定的复合物,减缓了淀粉的老化。同时乳化剂的复配能一定程度地加强抗老化的效果。总体上讲,糯质小麦淀粉的各种良好的理化特性,使其在淀粉基生物材料抗老化上有更好的应用前景。     

小麦B淀粉概述

小麦B淀粉是生产小麦淀粉、谷朊粉的副产物,其产量占面粉总量10%～20%;该文介绍小麦B淀粉来源、组分特点及其利用情况。     

Effect of pasta drying temperature on gastrointestinal digestibility and allergenicity of durum wheat proteins

The effects of different drying temperatures (20, 60, 85, 110 and 180 °C) on digestibility and potential allergenicity of durum wheat proteins were studied in model pasta samples, cooked in boiling water (MPSs). Increasing the drying temperature resulted in increased protein denaturation and aggregation. In vitro treatment of MPSs with pepsin and pancreatin showed similar protein degradability up to a drying temperature of 110 °C, resulting in the disappearance of the main prolamin components. In contrast, the MPS treated at 180 °C was much less digestible, due to the presence of Maillard-type protein aggregates.     

The influence of inulin addition on the morphological and structural properties of durum wheat pasta

The effect of the addition of different concentration of inulin fibre to durum wheat pasta was evaluated in terms of structure, texture and morphological characteristics. Inulin fibre fraction was incorporated into pasta at 5%, 10% and 15% inclusion rates. Changes to pasta quality were observed with inulin fibre fraction addition by scanning electron microscopy, X-ray diffraction and Raman spectroscopy methods. Investigation of pasta microstructure indicate a lowering in crystallinity increasing the inulin content and characterisation of starch gelatinisation events indicated that a combination of changes to the starch–protein matrix and the high water-binding capacity of inulin alters the physico-chemical properties and then the digestibility of the pastas.     

糯小麦与非糯小麦面粉糊化特性的比较

淀粉是小麦籽粒的重要组成部分,约占小麦粒重的70%～75%。淀粉糊化特性的不同是区分小麦类型、判断小麦淀粉品质特性的重要依据。实验以农大糯麦1号、糯227等5个糯麦品种及非糯小麦品种京411为材料,利用RVA测试其糊化特性,结果表明,糯麦与非糯小麦在峰值黏度、峰值时间、糊化温度等糊化特性参数上存在显著差异,而峰值黏度与小麦的糯性与否无关。     

Identification of durum wheat cultivars and monovarietal semolinas by analysis of DNA microsatellites

 Microsatellites isolated in bread wheat were used to identify 20 Italian durum wheat (Triticum turgidum var. durum L.) cultivars. A total of 15 microsatellite primer pairs were tested against DNA extracted from leaf tissue, single seeds and semolina. Twelve markers showed allelic polymorphism among the 20 cultivars, providing a total of 41 different alleles. Firstly, an analysis of microsatellite informativeness in the chosen set of durum wheat cultivars was made and a set of highly polymorphic microsatellites was established. Secondly, among the most polymorphic cultivars, the minimum number of microsatellites able to distinguish all cultivars was determined. A set of five microsatellites was found sufficient to differentiate the durum wheat cultivars examined. The method is directly applicable to seeds and semolina, and is suitable for detecting seed mixtures in the same seed lot. Received: 22 February 1999 / Revised version: 19 April 1999     

Environmental conditions affect semolina quality in durum wheat (Triticum turgidum ssp. durum L.) cultivars with different gluten strength and gluten protein composition

BACKGROUND: Sowing time may impact semolina and pasta cooking quality by changing the environmental conditions during grain filling. The effect of an optimum and a delayed sowing time on semolina quality was studied by comparing six cultivars under irrigation, in order to isolate temperature from drought effects. RESULTS: Protein content was higher in the old cultivars and in the late sowings, according to the number of days with temperature between 30 and 40 °C during ripening. Gluten index increased as temperature rose to a threshold of about 30 °C, then decreased under higher temperatures. Mixograph parameters were less sensitive to high temperatures. Gliadin:glutenin correlated with gluten strength. Spaghetti firmness and protein content were positively correlated independently of sowing date. Cultivars Trinakria and Cappelli had the highest spaghetti firmness (900 and 828 g). CONCLUSIONS: Late sowings may represent a way of increasing pasta cooking quality whenever they place grain filling under thermal conditions able to increase protein percentage, although the accompanying decrease in yield may represent a drawback in environments prone to drought stress during ripening. The lower protein percentages of modern durum wheat cultivars under conventional sowing times results in a lower pasta cooking quality despite higher gluten strength. Published 2011 by John Wiley & Sons, Ltd.