免化学试剂-离子色谱法测定小麦粉中溴酸钾的不确定度评定

利用离子色谱法测定了小麦粉中溴酸盐,对溴酸盐测量不确定度的来源进行了分析和量化评定.实验测得:当小麦粉中的溴酸盐含量为0.42mg·kg-1时,扩展不确定度为0.08mg·kg-1(k=2).     

NUMERICAL SIMULATIONS OF WHOLE FIELD BEHAVIOR FOR ROUND BUOYANT JET

ＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＳＯＦＷＨＯＬＥＦＩＥＬＤＢＥＨＡＶＩＯＲＦＯＲＲＯＵＮＤＢＵＯＹＡＮＴＪＥＴＬｉＷｅｉ，ＨｕａｉＷｅｎ－ｘｉｎ（ＷｕｈａｎＵｎｉｖｅｒｓｉｔｙｏｆＨｙｄｒａｕｌｉｃａｎｄＥｌｅｃｔｒｉｃＥｎｇｉｎｅｅｒｉｎｇ，...     

Physicochemical Properties of Bread Baked from Flour Blended with Immature Wheat Meal Rich in Fructooligosaccharides

ABSTRACT: Grain of the soft white wheat cultivar Harus was harvested weekly from anthesis to maturity and fructooligosaccharides (FOS) contents were determined by reversed-phase high-performance liquid chromatography. Tests were carried out to determine the effect of adding immature wheat meal to a base flour of cultivar Russ (hard red spring) on the quality characteristics of bread. FOS content was also analyzed in baked bread, and the effect of transglutaminase in improving bread quality was examined. Marked decreases in FOS contents, such as 1-kestose and nystose, were observed with grain maturation. The overall quality of bread appeared to be acceptable, and the added FOS were retained after baking.     

The current and residual value of superphosphate for lupins grown in rotation with oats and wheat on a deep sandy soil

In a field experiment on a deep pale-yellow sand in a 600 mm per annum rainfall Mediterranean environment of south-western Australia, six levels of phosphorus (P) as superphosphate (O up to 546 kg P ha^–1) were applied once only, to the soil surface, before sowing lupins (Lupinus angustifolius). The lupins were grown in a continuous arable cropping rotation with, in successive years, oats (Avena sativa), wheat (Triticum aestivum), lupins. Five such rotations were started in the experiment from 1985 to 1989. The experiment continued until the end of 1990.The relationship between lupin seed (grain) yields and the level of P applied was measured in the year of P application for five successive years (1985 to 1989). The relationship had the same general form but it varied between years, largely due to different maximum yields (yield plateaux) in each year.The residual value of superphosphate applied three years previously was measured for lupins on two occasions (1988 and 1989) relative to superphosphate applied in the current year. The residual values was different in the two years. The superphosphate applied three years previously was about 30% as effective as freshly applied superphosphate in 1988, and 12% as effective in 1989.At each harvest, the relationship between grain yield and the P concentration in the grain differed for different species. However, for each species at each harvest, the relationship was similar regardless of when the P was applied in the previous years. Thus each species had the same internal efficiency of P use curve, and yields varied only with P concentration in tissue.Bicarbonate-extractable soil P was determined on soil samples taken in mid-July of 1989 and 1990. These soil test values were related to grain yields at harvest. The relationship between yield and soil test values had the same general form but varied for different species within years and for each species between years. It also varied for each species within years depending on the year the P was applied.     

Solubilisation and Degradation of Wheat Gluten Proteins by Barley Malt Proteolytic Enzymes

Solubilisation and degradation of wheat gluten proteins by barley malt proteolytic enzymes (BMPE) was investigated with a model buffer system at pH 4.0 and pH 5.6, representing optimal pH for proteolysis and a pH value typical for beer brewing conditions respectively. Under the experimental conditions, incubation of commercial wheat gluten with BMPE solubilised 70% and 20% of the gluten proteins at pH 4.0 and pH 5.6 respectively. Gel permeation chromatography profiles and SDS‐PAGE showed that wheat gluten proteins were more degraded by BMPE at pH 4.0 than at pH 5.6. In a laboratory scale barley malt brewing experiment, proteins of worts, prepared with and without wheat gluten, were characterised. Results comparable to those in the model buffer system at pH 5.6 were obtained, which indicated that BMPE indeed solubilise wheat gluten during mashing, but that further degradation is rather limited under these conditions.     

麦胚高蛋白乳粉的研制及营养评价

研究了用麦胚浆液与牛乳混合生产高蛋白奶粉的方法。产品的主要特点是具有较高含量的赖氨酸，谷胱甘肽，磷脂，胆碱，不饱和脂肪酸等，这些成分对人体具非了非常的好健脑，抗衰老作用。     

整体成型钼园舟研究

本研究采用特殊的方法制取钼园舟，研究结果表明，获得了满意的结果。     

The effect of cooking on proteins from acha (Digitaria exilis) and durum wheat

The effect of cooking on proteins from acha and durum wheat was assessed from an analysis of protein extractability, gel electrophoretic profiles, in-vitro protein digestibility (IVPD) and the amino acid compositions of wholemeal flour and residue proteins. Heating wholemeal flour samples at 100–140°C (t = 10–40 min) resulted in 0–30% and 45–55% decreases in acha and durum protein solubility, respectively. In general, high molecular weight (30–70 k Da) protein subunits were more susceptible to heat damage. For both cereals, sodium dodecyl sulphate (SDS; 10 g litre^?1) and/or dithiothrcitol (DTT; 10 mM ) increased protein solubility in unheated and heated samples. The IVPD index was 90–91% and was not significantly altered by cooking (100–120°C, t = 40 min). Cooking at extreme temperatures (140°C, t = 40 min) reduced the IVPD by 8% (P = 0.05). Osborne fractionation resulted in a durum or acha residue level of 7.8% or 55.2%. Treatment with solvent containing propanol, SDS and/or DTT at room temperature followed by SDS-polyacrylamide gel electrophoresis of non-solubilised proteins showed that the glutelin fraction of acha, with the exception of a 65 kDa subunit, was insoluble owing to strong inter-subunit hydrophobic and disulphide interactions. Wholemeal acha flour and residue protein showed a significantly greater level of hydrophobic and sulphur amino acids as well as glutamine which is associated with H-bonding. The possibility that cereal protein solubility is also dependent on protein-carbohydrate links is discussed.     

Effect of precooking time and drying temperature on the physico-chemical characteristics and in-vitro carbohydrate digestibility of taro flour

Achu is a thick porridge obtained by cooking and pounding taro (Colocasia esculenta) corms and cormels in a mortar. This study was undertaken with the objective of producing precooked taro flour that can be used in the preparation of achu. Taro slices were precooked to times of 0, 20, 45 and 90 min and dried in an air convection oven at varying temperatures of 50, 60, 70 or 80 °C before milling into flour which was then analysed for its water absorption capacity (WAC), water solubility index, emulsion activity and stability, bulk density, foam capacity and least gelation concentration (LGC). Achu made from the flours were equally analysed for their relative penetrometric index, bulk density and colour. The results showed that precooking induced significant (P<0.05) decrease in foam capacity, penetrometric index, and increase in LGC, emulsion stability and WAC. The drying temperature also induces significant reduction in emulsion capacity and stability, penetrometric index, and increase in LGC, WAC. Long precooking time (>45 min) and drying temperature (>60 °C) induced significant reduction of the in-vitro carbohydrate digestibility of taro achu.     

Effect of fermentation on ionizable iron in cereal-pulse combinations

The average diet in most developing countries is predominantly cereal based. Wheat, rice and millets are major staple foods. Although these diets are sufficient in iron, their low bioavailability is one of the most significant factors for iron deficiency anaemia. Traditional techniques like fermentation show promise in improving iron bioavailability. In vitro ionizable iron was estimated in 31 different combinations of rice, wheat, sorghum, black gram, bengal gram, green gram and coriander in five replicates with or without, fermentation in steamed products. Results indicate that in general cereal pulse combination and fermentation significantly ( P <0.05) increase the per cent ape of ionizable iron. Combination effects dominated in rice whilst fermentation dominated in sorghum. There was a significant reduction ( P <0.05) in phytate phosphorus on fermentation but no loss of tannin.