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.     

Formulation optimisation of vegetable flour–loaded functional bread. Part II: effect of the flour hydration on the bread quality

In this work, the hydration process of durum wheat–based functional bread loaded with yellow pepper flour was optimised. In particular, the investigated vegetable flour and durum wheat semolina were mixed after they were separately hydrated. Three different amounts of water added to the yellow pepper flour were studied for assessing the effect of vegetable flour hydration level on the dough development and overall quality of bread. The bread formulation investigated in a previous work, based on 25% of yellow pepper and 2% of guar seed as structuring agent where the vegetable flour was directly added to the hydrated durum wheat semolina dough, was chosen as control sample. Results highlighted that dough samples with yellow pepper flour hydrated at highest water content showed a rheological behaviour similar to the durum wheat dough. Moreover, creep analysis showed that the sample added with no‐hydrated yellow pepper flour recorded the greatest resistance to deformation. Same results were obtained for the dough tensile and bread compression tests. The use of the hydrated yellow pepper flour also improved all sensorial attributes.     

Characteristic of filamentous fungal diversity and dynamics associated with wheat Qu and the traditional fermentation of Chinese rice wine

Chinese rice wine, a traditional alcoholic beverage, is fermented from steamed rice with a starter culture of wheat Qu which is either inoculated spontaneously with various microorganisms in natural environment or inoculated artificially with certain microorganisms. The diversity of filamentous fungi in wheat Qu and the fermentation mashes of Chinese rice wine was studied by high‐throughput sequencing. The results indicated that filamentous fungi varied in wheat Qu and fermentation periods. Moreover, Aspergillus was the dominant filamentous fungi at genus levels. On that basis, quantitative real‐time PCR was used to quantify some dominant Aspergillus species. It was found that Aspergillus species in wheat Qu were more abundant than that in various fermentation mashes and continually decreased until the end of rice wine fermentation. Furthermore, it was found that different organic acids were produced by microorganisms at different fermentation stages might due to the changes of oxygen and nutrient content.     

Evaluation of a hydrothermal process for pretreatment of wheat straw—effect of particle size and process conditions

BACKGROUND: Hydrothermal processes are an eco‐friendly processes that provide an interesting alternative for chemical utilization of lignocellulosic materials, in which water and crop residues are the only reagents. In this work the effect of process conditions (size distribution of the wheat straw, temperature and time) was evaluated against production of fermentable products. RESULTS: The use of milled wheat straw fractions as a raw material containing blends of different particle size distribution showed that the latter had an influence on the final sugars in the hydrolysate. Improved values of glucose (21.1%) and xylose yields (49.32%) present in the hydrolysate were obtained with treatment severity factors of 2.77 and 3.36, respectively. Mathematical models were developed aimed at establishing the effect of process conditions on monosaccharide concentration and its degradation in the liquor. CONCLUSION: This work shows that the use of wheat straw blends with various particle sizes has a significant effect on the extraction of fermentable products. The effect of treatment severity, which takes into account both processing time and temperature was also evaluated. These results are of importance for process design. Copyright © 2010 Society of Chemical Industry     

关于水分调节与稳定面粉水分的探讨

阐明小麦水分调节的概念,论述了水分调节对小麦籽粒、去石机筛面、研磨、筛理、清粉工序的影响;结合企业多年实际水分记录,通过对磨耗的影响因素的分析,得出加水量的计算公式,为实现入磨最佳水分,奠定理论基础。     

Experiments on dough rheology to improve screening of bread wheat cultivars

The bread‐making potential of flour may be roughly estimated by dough rheology, especially its tolerance to over‐mixing as determined with the farinograph. The objective of this study was to identify the relative effects of experimental conditions likely to affect dough mixing stability: mixer speed, temperature, salt, yeast and bread additives such as ascorbic acid and preservatives. The addition of 1–2% salt or ascorbic acid (50 mg kg^?1 flour) improved dough mixing stability and counteracted the negative effect of bread preservatives. Mixing salted dough at slow speed (63 rpm) and 25 °C might be a more realistic bread‐making procedure for performing dough rheology assays with equipment such as the farinograph, compared to official methods (only flour and water, no salt; 30 °C). Amongst five bread wheat cultivars, differences existed in dough strengthening response to both salt and ascorbic acid, a property that may find application in wheat breeding and screening.     

Improvers and functional ingredients in whole wheat bread: A review of their effects on dough properties and bread quality

BackgroundDespite the associated health benefits of whole grains, consumption of whole grain products remains far below recommended levels. Whole wheat bread is often associated with many distinctive attributes such as low loaf volume, firm and gritty texture, dark and rough crust and crumb appearance, bitter flavor, and reduced shelf-life. There is a need to improve its quality and sensory characteristics so as to increase consumer appeal and, ultimately, increase the intake of whole wheat bread. The inclusion of various ingredients improves dough and bread properties.Scope and approachThis review examines the effects of enzymes, emulsifiers, hydrocolloids, and oxidants on the properties of whole wheat bread and dough, with particular attention to effects on loaf volume and hardness. Wheat gluten and other plant materials are also discussed. Gaps in the research into whole wheat bread are identified, and future research needs are recommended.Key findings and conclusionsXylanase reduces the water absorption of whole wheat flour and increases loaf volume and crumb softness by hydrolyzing ararbinoxylans. α-amylase can be beneficial under certain conditions. Phytase may activate endogenous α-amylase. G4-amylase is promising but needs validation by further research on its effect on loaf volume, crumb hardness, and staling. Vital wheat gluten overcomes many of the challenges of whole wheat bread production and is found in the majority of commercial whole wheat breads. Emulsifiers DATEM and SSL can improve the volume, texture and staling profile of whole wheat bread. Several types of improvers are generally needed in combination to provide the greatest improvement to whole wheat dough and bread.     

影响优质小麦粉质量和出率的因素

本文就面粉厂生产中影响优质小麦粉质量和出率的几个因素进行了分析,并分别对各种问题提出了改进的方法和建议.     

醌及氢化醌类化合物对麦草蒸煮的作用及其数学模型

本文研究了蒽醌（AQ）及其衍生物以及氢化蒽醌对麦草烧碱法蒸煮的作用，用微型计算机处理蒸煮结果，得到7个关于添加剂用量与蒸煮效果关系的数学模型，并对蒸煮过程进行了分析。研究结果表明，氢化蒽醌是比较适合麦草制浆的蒸煮添加剂。