Spaghetti cooking quality of waxy and non‐waxy durum wheats and blends

Quality attributes of waxy durum wheat (Triticum turgidum L), milled semolina and cooked spaghetti were examined and compared with those of two non‐waxy durum cultivars. With the exception of kernel hardness, wheat quality characteristics were similar for both waxy and non‐waxy durum. Compared with average values obtained for durum wheat grown in North Dakota (USA) during the crop year 2000, the values obtained for the wheat used in this study were equal or better for most parameters evaluated. Semolina extraction for all samples was lower than the 2000 average of 62.6%. The waxy lines had higher ash, lower speck count, similar protein quantity, lower wet gluten and stronger mixograph curves than the non‐waxy cultivars. Waxy durum semolina had higher lipid content, starch damage, stirring number and flour swelling values. Spaghetti made from waxy durum semolina had shorter cooking time, similar cooking loss and cooked weight and lower firmness values, which would be unacceptable by most standards. Spaghetti made from blends containing 20–80% waxy durum semolina were evaluated. Cooking time and firmness decreased and cooking loss increased as the amount of waxy semolina increased. Acceptable spaghetti was obtained using 20–40% waxy semolina blends, depending on the quality of the non‐waxy blending material. Copyright © 2004 Society of Chemical Industry     

超微处理挤压改性荞麦粉添加对面团特性和全荞麦面条品质特性的影响

将经挤压改性的荞麦粉超微处理,将不同比例物理改性粉回添后制成面团和面条。利用混合实验仪、动态流变仪和扫描电子显微镜研究其添加量对面团热机械学、拉伸和流变特性及微结构的影响,结合全荞麦面条蒸煮、质构特性和感官评定结果,研究其对面条品质的影响。结果发现,随添加量的增加,面团的吸水率递增,形成时间先递减后递增,稳定时间和拉伸阻力先递增后递减,峰值扭矩和回生值均递减。其中添加量为5%和10%的面团结构紧实且连续均匀,孔洞较小,黏弹性较高。加工后的面条吸水率、蒸煮损失和断条率随添加量的增加先降低后上升,硬度、弹性和咀嚼度变化趋势相反,蒸煮时间逐渐降低。添加量为5%时,面条具有最好的蒸煮和质构特性和感官评定值。     

Effect of formulation and processing parameters on acrylamide formation: A case study on extrusion of blends of potato flour and semolina

Acrylamide formation in extruded snacks prepared using blends of potato flour:semolina in ratios ranging from 30:70 to 70:30 showed maximum acrylamide formation in the 70:30 blend. The extrusion was carried out at a screw speed of 120 rpm, temperature of 170 °C and moisture content of 18%. Further, the influence of extrusion processing parameters on the acrylamide formation in extruded snacks prepared from a 70:30 blend of potato flour:semolina was investigated using response surface methodology (RSM). The feed moisture was varied from 12.6% to 19.4%, die temperature from 163 to 197 °C and screw speed from 106 to 173 rpm. The extrudates so obtained showed acrylamide content ranging from 704 to 1560 μg/kg. The effect of different additives such as citric acid, calcium salts, amino acids, vitamins and their combinations on the mitigation of acrylamide formation showed calcium chloride at 50 μmol/g flour blend to reduce acrylamide formation by 65% without altering the sensory properties of the extrudates.     

Eating quality of low‐fat beef burgers containing fat‐replacing functional blends

Tapioca starch, carrageenan, oat fibre, pectin, whey protein and a commercial mixture of carrageenan and locust bean gum were assessed for their ability to mimic fat characteristics in cooked low‐fat (10%) beef burgers. Thirteen different blends of the ingredients were formulated in order to examine their effects on quality parameters of low‐fat beef burgers. The beef burgers were tested for cook yield, water‐holding capacity (WHC), retention of shape, sensory and mechanical texture analysis. Most blends significantly (P<0.05) increased both cook yield and WHC, in particular blends containing tapioca starch, oat fibre, whey protein and the carrageenan/locust bean gum mixture. These blends substantially reduced both Warner–Bratzler and Kramer shear values. Sensory analysis showed that beef burgers containing tapioca starch, oat fibre and whey protein were acceptable in terms of flavour and texture. The low‐fat control was found to be the toughest and driest of the beef burgers examined. This study shows that blends of these ingredients can be used to offset the poor quality associated with low‐fat beef burgers. © 1999 Society of Chemical Industry     

复合全谷物(黑小麦、荞麦、燕麦)挤压膨化产品的配方优化研究

以黑小麦、荞麦、燕麦为原料,通过挤压膨化技术,研究大豆蛋白、大豆卵磷酯及蔗糖等配料对复合全谷物挤压膨化产品品质的影响。结合模糊数学综合评判方法,对挤压膨化产品进行感官评定,以膨化率和感官评定结果作为产品综合评分,采用响应面分析法对挤压膨化产品配方进行优化,得到全谷物挤压膨化产品的最佳配方为：大豆蛋白3.3%,大豆卵磷酯0.4%,蔗糖8.3%。在此优化条件下,复合全谷物挤压膨化产品的综合评分为3.94。     

Characteristics and oil absorption of deep‐fat fried dough prepared from ball‐milled wheat flour

BACKGROUND: High levels of oil in fried products has been recognized as causing health problems. The formation of microstructure during frying is one factor that influences oil absorption. Above the glass transition temperature (T_g), the physical properties of a polymer influences the formation of structure. The ball‐milling process changes the physicochemical properties of wheat flour constituents. The present study investigated the effects of physicochemical changes in wheat flour by the ball‐milling process on structure formation and oil absorption in wheat flour dough model. RESULTS: Dough samples were made from wheat flour that had been ball‐milled for 0 to 10 h and then fried in frying oil at 150 °C for 1–7 min. Thermal properties of wheat flour, structure alteration, and textural properties of fried samples were evaluated. As compared with samples made of non‐milled flour, samples made from milled flour had smaller pores and higher oil absorption. The fracture force of a fried sample prepared from non‐milled flour was lower than that of a sample prepared from milled flour. CONCLUSION: Ball‐milling affected the microstructure formation in fried wheat flour dough, and subsequently oil absorption. The crispness of a sample prepared from non‐milled wheat flour is higher than that of a sample prepared from ball‐milled wheat flour. This may be due not only to a plasticization effect, but may also be dependent on microstructure. Copyright © 2008 Society of Chemical Industry     

Effect of Different Extrusion Parameters on Dietary Fiber in Wheat Bran and Rye Bran

Wheat bran and rye bran are mostly used as animal feed today, but their high content of dietary fiber and bioactive components are beneficial to human health. Increased use of bran as food raw material could therefore be desirable. However, bran mainly contains unextractable dietary fiber and deteriorates the sensory properties of products. Processing by extrusion could increase the extractability of dietary fiber and increase the sensory qualities of bran products. Wheat bran and rye bran were therefore extruded at different levels of moisture content, screw speed and temperature, in order to find the optimal setting for increased extractability of dietary fiber and positive sensory properties. A water content of 24% for wheat bran and 30% for rye bran, a screw speed of 400 rpm, and a temperature of 130 °C resulted in the highest extractability of total dietary fiber and arabinoxylan. Arabinoxylan extractability increased from 5.8% in wheat bran to 9.0% in extruded wheat bran at those settings, and from 14.6% to 19.2% for rye bran. Total contents of dietary fiber and arabinoxylan were not affected by extrusion. Content of β‐glucan was also maintained during extrusion, while its molecular weight decreased slightly and extractability increased slightly. Extrusion at these settings is therefore a suitable process for increasing the use of wheat bran and rye bran as a food raw material.     

Effect of gaseous ozone treatments on DON,microbial contaminants and technological parameters of wheat and semolina

Deoxynivalenol (DON) is an important mycotoxin produced by several species of Fusarium. It occurs often in wheat grain and is frequently associated with significant levels of its modified form DON-3-glucoside (DON-3-Glc). Ozone (O₃) is a powerful disinfectant and oxidant, classified as GRAS (Generally Recognised As Safe), that reacts easily with specific compounds including the mycotoxins aflatoxins, ochratoxin A, trichothecenes and zearalenone. It degrades DON in aqueous solution and can be effective for decontamination of grain. This study reports the efficacy of gaseous ozone treatments in reducing DON, DON-3-Glc, bacteria, fungi and yeasts in naturally contaminated durum wheat. A prototype was used to dispense ozone continuously and homogeneously at different concentrations and exposure time, in 2 kg aliquots of durum wheat. The optimal conditions, which do not affect chemical and rheological parameters of durum wheat, semolina and pasta, were identified (55 g O₃ h^?1 for 6 h). The measured mean reductions of DON and DON-3-Glc in ozonated wheat were 29% and 44%, respectively. Ozonation also produced a significant (p < 0.05) reduction of total count (CFU/g) of bacteria, fungi and yeasts in wheat grains.     

麦麸超微粉对面团特性及制品品质的影响

对超微粉碎麦麸粉面团的流变学特性进行研究,分别将超微粉碎麦麸(添加质量分数分别为0%、5%、10%、15%、20%)添加到面粉中并调制成面团,测定并记录其粉质特性和拉伸特性等。结果表明：麦麸超微粉的添加会使面粉的吸水率增大,面团形成时间、弱化度均有所增加,面团的稳定时间呈下降趋势;从粉质特性总体来看,超微麦麸粉的添加能改善面粉的粉质特性。在麦麸超微粉添加量在10% 时,麦麸超微粉馒头样品模糊综合评价结果为良好,其色泽、气味、组织结构、口感都可以被人接受。     

Effect of endo‐xylanase‐containing enzyme preparations and laccase on the solubility of rye bran arabinoxylan

Three commercial enzyme preparations with endo‐xylanase activity, namely Bio‐Feed Wheat, Bio‐Feed Plus and Grindamyl H 640, and laccase have been tested for their effects on the solubilisation of arabinoxylan (AX) in rye bran or autoclaved rye bran. Autoclaving efficiently increased the availability of AX for enzymatic degradation. Both Bio‐Feed Wheat (a monocomponent enzyme) and Bio‐Feed Plus (a multicomponent preparation with different enzymatic activities) efficiently degraded the autoclaved rye bran AX into lower‐molecular‐weight fragments. As much as 70% of the xylose residues and 58% of the arabinose residues in the autoclaved bran were soluble after treatment with Bio‐Feed Plus; the weight—average molecular weight of the detectable portion of these soluble polymers was 104 000 Da. Grindamyl H 640 solubilised only a small fraction of the AX in autoclaved rye bran; the molecular weight of these soluble fragments was higher than that of those released by the Bio‐Feed xylanases. Addition of laccase during treatment with Bio‐Feed Wheat or Grindamyl H 640 decreased the yield of water‐soluble AX. © 2003 Society of Chemical Industry     

谷朊粉对高含量荞麦面团的影响及其作用机理

本文全面研究了不同添加量谷朊粉(5%、10%和15%)对高含量(50%小麦粉替代率)荞麦面团流变学特性及馒头品质的影响,并以添加10%谷朊粉的混合面团和参照组(纯小麦粉)面团为基础,通过扫描电镜,红外光谱及分析面团中的化学作用力等分析手段,进一步探讨了谷朊粉对改善混合面团流变学性质及馒头品质方面的作用机理。结果表明,添加10%的谷朊粉能够增加荞麦-小麦混合面团中二硫键的含量,改变面团中的化学作用力(离子键、氢键含量和疏水作用力),进而改变面团中面筋蛋白的构象,改善面团的微观结构,从而改善混合粉的糊化特性及面团的粉质和拉伸特性,提高馒头的比容和弹性,改善馒头芯的孔隙结构,但仍达不到参照组馒头的品质,表明添加高含量荞麦全粉不仅仅是稀释面筋蛋白。     

Development of high‐performance liquid chromatography and non‐aqueous capillary electrophoresis methods for the determination of fenoxycarb residues in wheat samples

BACKGROUND: Practical methods for the analysis of fenoxycarb residues in wheat samples were developed using high‐performance liquid chromatography (HPLC) and non‐aqueous capillary electrophoresis (NACE). RESULTS: Fenoxycarb residues in wheat were extracted with acetone by ultrasonication, followed by a clean‐up procedure with liquid–liquid extraction with 5% NaCl/dichloromethane. The HPLC was developed using C18 as column, MeOH/water (6:4, v/v) as the mobile phase and 199 nm as the detection wavelength. The optimal NACE condition was established with the running buffer of 20.0 mmol L^?1 NH₄Ac in 95% MeOH (pH* 9.0), and the applied voltage of 30 kV over a capillary of 50 µm i.d. × 48.5 cm × 40 cm effective length. Both methods gave the relatively lower limits of detection (0.008 mg kg^?1 for HPLC and 0.024 mg kg^?1 for NACE) and the higher recoveries (>85.0%). They were successfully applied to the determination of fenoxycarb in wheat samples. CONCLUSION: The results showed that the fenoxycarb residue gradually reduced to trace amounts after about 3 years, which implied that the pharmacological actions of fenoxycarb could last for about 3 years. Meanwhile, more effort should be made to control and reduce fenoxycarb residues because of its potential health risks to consumers. Copyright © 2007 Society of Chemical Industry     

Sensory and compositional attributes of melting‐ and non‐melting‐flesh peaches for the fresh market

A study was conducted to determine differences in sensory and compositional characteristics of melting‐flesh (MF) and non‐melting flesh (NMF) fresh market peach genotypes. Sensory results showed that the NMF fruit (‘Oro A’ and FL 86‐28C) were ‘harder’, less ‘juicy’ and more ‘rubbery’ than their MF (FL 90‐20 and ‘TropicBeauty’) counterparts. A principal component analysis of the sensory data showed a clear distinction between the textural aspects of MF and NMF fruit, but not between their flavour aspects. Likewise, chemical analysis showed that while differences in pH, titratable acidity, and soluble solids were detected among the four genotypes, no consistent grouping could be made based on the MF/NMF nature of the fruit. © 1999 Society of Chemical Industry