Effect of blending durum wheat flour with hard white wheat flour on the quality of yellow alkaline noodles

Yellow alkaline noodles (YAN) were prepared from durum and hard white wheat flour blends and evaluated for noodle color, appearance and cooked noodle texture. Raw noodle brightness, L^∗, and yellowness, b^∗, improved significantly with durum flour addition while significant increases in a^∗ values were observed at both 2 h and 24 h. The very low noodle speck count of white wheat noodles remained constant over the 24 h period at any durum flour addition. Noodle bite, MCS, decreased with the addition of durum flour, resistance to compression (RTC) remained equivalent to the hard white flour control while an associated improvement in cooked noodle recovery (REC) was observed. The study indicates that addition of durum flour at even the 25% level, offers a viable product with improved colour characteristics, consistent RTC and improved REC textural attributes. Uniaxial stress relaxation parameters of cooked noodles significantly correlated with the empirical texture measurements.     

Processing and characterization of durum wheat bread enriched with antioxidant from yellow pepper flour

The effect of the addition of yellow pepper flour on bread physico-chemical and sensorial properties was addressed in this study. In particular, vegetable flour concentration was set at 25%; in order to optimize the bread sensorial properties, yellow pepper flour was separately hydrated at three different water content levels. Texture analysis were carried out on both dough and bread samples to evaluate their firmness. Furthermore, tomographic analysis was performed on the same samples in order to provide a more detailed view of their texture. Estimation of the glycemic response, determination of the carotenoids content and sensory analysis of the fortified bread were also determined. Results highlighted that the highest glycemic index was achieved in bread sample having the highest water content and that showed the worst results in terms of texture. Among the studied samples, bread with medium hydration level showed good structural characteristic, double anti-oxidant content compared to the control bread (CTRL S) and the highest sensorial quality.     

Evolution of functional,thermal and pasting properties of sprouted whole durum wheat flour with sprouting time

This research investigated the evolution of functional, pasting and thermal properties of durum wheat (Triticum durum) with sprouting time. Particle size, flour and flour gel hydration properties (Water Holding Capacity (WHC), Swelling Volume (SV), Water Absorption Index (WAI), Water Solubility Index (WSI), Swelling Power (SP)), Oil Absorption Capacity (OAC), Pasting and thermal properties were evaluated on different sprouting time: 12, 24, 36, 48 and 72 h. Results showed that more than 12 h decreased significantly particle size, WHC(−14.8%), SV (−19%), SP (−14%) and WAI (−36.5%) while WSI (+383%) and OAC (+7.3%) increased. Pasting properties drastically decreased with sprouting time. DSC results showed a significant increase in onset temperature (T₀) (from 55.2 to 58.2 °C), peak temperature (T_p) (from 62.4 to 63.8 °C) while conclusion temperature T_c decreased (from 76 to 72.6 °C). Despite these changes, sprouted whole wheat flour could be suggested as an improver of some cereal products’ functionality.     

Detection of wheat adulteration of spelt flour and products by PCR

 To date, no general method to detect wheat [Triticum aestivum vulgare (Vill.) Mackey] adulteration of spelt [T. aestivum spelta (L.) Thell.] exists. Exploiting a published allelic difference in γ-gliadin gene GAG56D, we developed and evaluated three PCR-based methods to determine the proportion of wheat in spelt flour and products. A sensitive wheat-specific PCR system was designed. Moreover, a heterologous internal standard was constructed for quantitative competitive (QC-)PCR. The standard was arbitrarily calibrated to 5% wheat DNA in spelt DNA. A PCR-RFLP system consisting of a GAG56D-specific PCR system with subsequent restriction was used to estimate the relative proportions of wheat and spelt in DNA mixtures. The three methods were successfully applied to seven commercial spelt samples and one self-produced bread. Five and three of the seven samples were found to contain more than 5% and 10% wheat, respectively. One sample appeared to contain no spelt at all. Analyzing the bread crumb with PCR-RFLP, we were able to estimate the wheat content of the flour which was used to produce the bread and thus demonstrated the applicability of PCR-RFLP to quantify processed products. Received: 24 March 2000     

Rapid detection and quantification of milk adulteration using infrared microspectroscopy and chemometrics analysis

The application of attenuated total reflectance mid-infrared microspectroscopy (MIR-microspectroscopy) was evaluated as a rapid method for detection and quantification of milk adulteration. Milk samples were purchased from local grocery stores (Columbus, OH, USA) and spiked at different concentrations of whey, hydrogen peroxide, synthetic urine, urea and synthetic milk. Samples were place on a 192-well microarray slide, air-dried and spectra were collected by using MIR-microspectroscopy. Pattern recognition analysis by Soft Independent Modeling of Class Analogy (SIMCA) showed tight and well-separated clusters allowing discrimination of control samples from adulterated milk. Partial Least Squares Regression (PLSR) showed standard error of prediction (SEP) ∼2.33, 0.06, 0.41, 0.30 and 0.014 g/L for estimation of levels of adulteration with whey, synthetic milk, synthetic urine, urea and hydrogen peroxide, respectively. Results showed that MIR-microspectroscopy can provide an alternative methodology to the dairy industry for screening potential fraudulent practice for economic adulteration of cow’s milk.     

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     

Isolation and partial characterisation of two low molecular weight durum wheat (Triticum durum) glutenins

Two low molecular weight durum wheat (Triticum durum Desf) glutenins, DSG-1 and DSG-2 (durum-wheat sulphur-rich glutenin fractions) were isolated from two cultivars, Mondur of good technological quality and Kidur of poor technological quality. The glutenin fraction, composed mostly of DSG protein, was extracted using a low concentration of NA-tetradecanoate and then fractionted by by using molecular sieve chromatography (Bio-Gel P 30). The amino acid compositions and the N-terminal sequences of the pure DSG proteins were determined, and their hydrophobic characteristics, calculated on the basis of these data, showed that DSG-2 is more hydrophobic than DSG-1. The amino acid compositions of DSG-1 and DSG-2 were different. The N-terminal amino acids of DSG-1 and DSG-2 were also different but were identical for each of the two cultivars. In the case of DSG-1, in addition to the main chain a minor chain was found in which the first three amino acids of the main chain were missing. The minor chain represented about 30% int he DSG-1 of mondur and almost 50% in Kidur.     

Ultra-performance liquid chromatography (UPLC) quantification of carotenoids in durum wheat: Influence of genotype and environment in relation to the colour of yellow alkaline noodles (YAN)

Carotenoids are the main compounds responsible for the yellow colour of durum wheat semolina and flours. However, the concentration of carotenoids in wheats depends on genotype and growing environments. The total pigment and carotenoid concentration of four durum wheat varieties (AC Avonlea, Commander, AC Navigator and Strongfield) and two common wheat varieties (AC Barrie and AC Snowbird), which were grown in different locations in Saskatchewan, Canada (Taber, Regina and Swift Current), were determined using the AACC International approved method and ultra-performance liquid chromatography (UPLC). A fast (within 6 min) and sensitive method for separation of carotenoids extracted from durum wheat flours was developed using UPLC. The results show that Commander and AC Navigator varieties exhibited higher total pigments and lutein concentration than the other wheats. Wheat grown in Taber and Swift Current regions had higher total pigments and lutein concentration than those grown at Regina. Although carotenoids in wheat extracts possessed antioxidant properties there was no significant correlation between antioxidant capacity and the concentration of carotenoids in the extracts (r² = 0.13). The carotenoid extracts from AC Barrie exhibited the highest DPPH radical scavenging, while AC Avonlea showed the lowest. The concentration of extracted lutein highly correlated (r² = 0.93) with the yellowness, b^* value, of the yellow alkaline noodles, whereas the correlation between lutein concentration and noodle redness, a^*, or brightness, L^*, values were not as strong (r² = 0.75 or 0.58, respectively). Thus, the high concentration of lutein in the durum wheats contributes to the desirable greater yellowness of yellow alkaline noodle, an important key to making a healthy yellow alkaline noodle without artificial yellow agent.     

Effects of industrial processing on the distributions of deoxynivalenol, cadmium and lead in durum wheat milling fractions

The aim of this work was to investigate the distributions of deoxynivalenol, cadmium and lead in durum wheat milling fractions from industrial milling plants. The study focused on two milling technologies: conventional milling and debranning before milling. Initial analyses of samples of all raw materials showed contamination levels considerably lower than the limits imposed by the European Commission. Deoxynivalenol, cadmium and lead showed rather similar patterns of distribution. Semolina had lower, although not significant levels of these undesirable substances than unprocessed wheat grain; in contrast, marked concentration factors were found for the contaminants in shorts (middlings) and flour shorts. Debranning technology resulted in higher contamination levels in products intended for animal feed than conventional milling. The difference was statistically significant for deoxynivalenol and lead contamination of the shorts (middlings) fraction. As the outer parts of the kernel are generally considered richer in inorganic elements and moulds, Pearson's correlation was performed to investigate the relationship between the crude fibre contents of the different fractions, adopted as bran marker, and contaminant levels. Positive correlations were found for each of the three contaminants, although the correlation coefficients were not very high, demonstrating that crude fibre likely does not constitute a good marker for describing contaminants repartitioning in milling fractions when the levels of these substances are low.     

Use of durum residue flour,a lower value product of durum milling,by incorporation into wheat flour dough without deterioration in baking quality

BACKGROUND: During the milling of durum wheat to semolina, about 10–15% of total products produced is residue flour, a lower value product than the semolina. This study investigated the potential for using the durum residue flour as an additive in bread‐making to improve its potential commercial value. RESULTS: Incorporation of residue durum flour from 102 breeding lines into a low protein flour and standard bakers' flour at 20% incorporation improved the bake loaf volume with minimal change in Mixograph dough mixing time and peak resistance in many of the lines tested. Loaf yellow b was always increased even with only a 10% incorporation. Baking flours can tolerate 20% incorporation with no deleterious affects on loaf volume and bake score. CONCLUSION: The results show a potential for using the lower value durum residue flour for baking bread of acceptable quality with a slightly higher yellow colour. This would improve the profitability for the miller and provide alternative ingredients to the baker for preparing specialty breads. Copyright © 2008 Crown in the Right of the State of New South Wales and Society of Chemical Industry     

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.     

Determination of benzoyl peroxide, as benzoic acid, in wheat flour by capillary electrophoresis compared with HPLC

BACKGROUND: In recent years, debate on the addition of benzoyl peroxide (BP) to wheat flour has increased in China. Medical studies have so far not confirmed that BP in wheat flour causes definite damage to the human body, but its main metabolite in the human body is benzoic acid. The addition of BP to wheat flour has been forbidden in China since 1 May 2011. It is therefore necessary to develop a suitable method to determine BP in wheat flour. RESULTS: A simple method using capillary electrophoresis (CE) was developed for determination of BP in wheat flour. BP was determined as benzoic acid after preceding reduction by potassium iodide. Separation was completed in less than 7 min with a running buffer of 10 mmol L^?1 sodium borate (pH 9.18), 4 s hydrodynamic injection, 25 kV separation voltage and UV detection at 228 nm. The method was validated in terms of linearity, sensitivity, detection limit, precision and accuracy. The detection limit was 0.29 µg mL^?1. The method was successfully applied to the determination of BP in wheat flour samples, with recoveries between 96.1% and 102.6%. CONCLUSION: The performance of the CE method was comparable, and the quantitative results were in good agreement with those using high‐performance liquid chromatography (HPLC). Meanwhile the proposed CE method has the advantages of better resolution, shorter analysis time and lower cost, and would be a good alternative to HPLC for routine monitoring of BP amount in wheat flour. Copyright © 2011 Society of Chemical Industry     

Detection of the adulteration of olive oils by solid phase microextraction and multidimensional gas chromatography

The presence or absence of filbertone in 21 admixtures of olive oil with virgin and refined hazelnut oils obtained using various processing techniques from different varieties and geographical origins was evaluated by solid phase microextraction and multidimensional gas chromatography (SPME–MDGC). The obtained results showed that the sensitivity achievable with the proposed procedure was enough to detect filbertone and, hence, to establish the adulteration of olive oil of different varieties with virgin hazelnut oils in percentages of up to 7%. The very low concentrations in which filbertone occurs in some refined hazelnut oils made difficult its detection in specific admixtures. In any case, the minimum adulteration level to be detected depends on the oil varieties present in the adulterated samples. In the present study, the presence of R- and S-enantiomers of filbertone could be occasionally detected in olive oils adulterated with 10–20% of refined hazelnut oil.     

糯小麦粉与普通小麦粉配粉对面条品质影响的研究

选用普通小麦品种中北439与糯小麦品种中糯一号制粉后进行配粉试验,研究糯性小麦粉对普通小麦粉的糊化特性和流变学特性的影响,以及对其制品面条品质的影响.     

Separation by solid phase extraction and quantification by reverse phase HPLC of sulforaphane in broccoli

The separation and quantification of sulforaphane [1-isothiocyanato-4-(methyl-sulfinyl)-butane] from the florets, stalks and leaves of broccoli is described. The procedure uses solvent extraction, followed by purification of extracts using solid phase extraction (SPE) and reverse phase HPLC analysis. The HPLC method is compared with a spectrophotometric assay. To obtain information about the usefulness of acid hydrolysis of glucosinolates, the florets were left to autolyze at room temperature or were treated with concentrated hydrochloric acid, then analysed. The method proves reliable and reproducible as regards both SPE purification and chromatographic determination. Quantities of sulforaphane were found in the florets, stalks and leaves. The highest content of sulforaphane (110 μgg⁻¹) was found in the leaves.     

基于差示扫描量热法的大豆原油掺伪 鉴别方法的建立

目的应用差示扫描量热仪(DSC)和油脂氧化稳定性测试仪(OSI)测试掺伪大豆原油的氧化稳定性(以诱导氧化时间表示),从而建立大豆原油掺伪的分析鉴别方法。方法设定OSI仪的氧化温度为110℃,氧气流量为20 L/h,DSC的氧化温度为110、120、130℃,氧气流量为50 m L/min,选择最佳氧化温度。记录各方法的诱导氧化时间。结果 DSC的诱导氧化时间随氧化温度提高不断缩短,确定130℃为DSC方法最佳氧化温度,不同比例掺伪大豆原油的OSI法的诱导氧化时间为320~495 min,DSC法诱导氧化时间为40~80 min。随着掺伪浓度增大,诱导氧化时间不断缩短。OSI法的掺伪检出限为掺伪浓度5%,DSC法的掺伪检出限为掺伪浓度10%。两种方法具有显著的正相关性:To(OSI110)=5.2480To(DSC130)+77.6799,r=0.9951。结论两种方法均可用于大豆原油掺伪鉴别,但DSC方法用量小,检测时间短,更适用快速鉴别。     

滴定法检测小麦粉中溴酸钾含量

利用溴酸钾在酸性溶液中与碘化钾反应析出碘,用硫代硫酸钠标准溶液滴定定量的原理,使用滴定法测定小麦粉中溴酸钾的含量,操作简便,最低检测限0.01 g/kg,回收率83%～107%,变异系数都在5%之内,方法准确可靠.