稀碱法分离工艺对糯米中蛋白质提取率的影响

探讨了稀碱法分离工艺对糯米中蛋白质提取率的影响,以得到纯度较高的糯米蛋白和糯米淀粉。研究碱液浓度、温度、水料比和时间对提取率的影响,采用响应面法对工艺参数进行优化,通过软件对提取率的二次多项数学模型解逆矩阵分析,最佳提取工艺为:碱液浓度0.05 mol/L、温度45.68℃、水料比8、时间94.96 m in。在上述工艺条件下蛋白提取率为80.11%,蛋白纯度为77.53%(干基),淀粉提取率为89.61%,淀粉纯度为90.50%(干基)。     

红曲霉在甜米酒酿造中的应用研究

红曲霉在生长过程中能产生大量的天然红曲色素,同时产生多种酶类,如淀粉酶、糖化酶、酯化酶等。本实验以红曲霉为甜米酒酿造的糖化增香着色剂,采用正交实验寻找适宜的红曲甜米酒酿造工艺。结果表明:红曲霉接种量20%,发酵温度35℃,发酵时间120h,在此工艺条件下酿制的甜米酒色泽红亮,味甜醇厚,酒体协调,有红曲特有的醇香。     

Evaluation of the effect of Ultra Rice® EDTA supplementation on the soluble iron,visual acceptance and vitamin A stability of commercial milled rice blends

The addition of NaFeEDTA at only 5% of total iron to ferric pyrophosphate‐fortified Ultra Rice^® increased the in vitro soluble iron ten‐fold. Ultra Rice^® formulated with NaFeEDTA at 2–7% of total iron, or with Na₂EDTA·2H₂O at 0.5× the total iron equivalents, increased the soluble iron seven‐ to thirty‐fold. The colour of the batches was acceptable through 20 weeks at 21 °C, but colour stability needs to be evaluated under authentic storage conditions. Although only 34–46% of the initial vitamin A remained after extrusion, 18‐week storage at 30 °C/70% relative humidity, and simulated cooking, there were indications that losses could be decreased by raising the pH (to ~5) and/or using a better protected vitamin A ingredient. The enhancement of soluble iron afforded by low‐level NaFeEDTA or Na₂EDTA·2H₂O supplementation suggests that this fortification strategy may merit further study as a means of increasing absorbable iron in Ultra Rice^®.     

Effect of Difference Weed Control Methods to Yield of Lowland Rice in the SOBARI

Weed competition will reduce rice yield. The research aimed to study the effect of difference weed control methods on rice yield in SOBARI. It has been conducted from October 2013 until February 2014, using Randomized Block design with five treatments (A = manual weeding, B = unweed control, C = herbicide containing Penoxulam + Cyhalofop-butyl, D = Bispyribac sodium, and E = 2, 4 D + Methyl metsulfuron). The results showed that weed control using herbicides containing Bispyribac sodium and 2.4 D + Methyl metsulfuron showed similar results as manual weed control on rice yield.     

Simple validated method for simultaneous determination of deoxynivalenol,nivalenol, and their 3-β-D-glucosides in baby formula and Korean rice wine via HPLC-UV with immunoaffinity cleanup

A simple and reliable method for the simultaneous determination of major type B trichothecene mycotoxins, deoxynivalenol (DON) and nivalenol (NIV), along with their 3-β-d-glucosides (DON-3-glucoside (DON3G) and NIV-3-glucoside (NIV3G)) in baby formula and Korean rice wine was validated in the present study. The method was based on immunoaffinity cleanup followed by analysis using an HPLC-UV technique. The method was validated in-house for two matrices as follows: linearity (R² > 0.99) was established in the range of 20–1000 μg kg^–1; accuracy (expressed as recovery) ranged from 78.7 to 106.5% for all the analytes; good intermediate precision (relative standard deviation < 12%), and adequate detection and quantitation limits (< 4.4 and < 13.3 μg kg^–1, respectively) were achieved. Furthermore, the estimated measurement expanded uncertainty was determined to be 4–24%. The validated method was successfully applied to the analysis of 31 baby formulas and Korean rice wines marketed in Korea.     

Developing radio frequency technology for postharvest insect control in milled rice

Since methyl bromide fumigation has an adverse effect on human health and environment, it is urgently needed for developing a non-chemical method to replace chemical fumigation for disinfesting milled rice. The purpose of this research was to study possible applications of radio frequency (RF) energy for disinfesting milled rice without affecting product quality. A pilot-scale, 27.12 MHz, 6 kW RF system was used to study RF heating uniformity and develop a treatment protocol for achieving 100% insect mortality and finally evaluating quality attributes in RF treated milled rice during storage. The results showed that the heating time needed only 4.3 min to heat the 3.9 kg milled rice from 25 °C to 50 °C using RF energy, but 480 min for milled rice to reach 48 °C using hot air at 50 °C. After comparing three selected electrode gaps, an appropriate gap of 11 cm was obtained to achieve the heating rate of 5.8 °C/min for further heating uniformity tests. An RF treatment protocol was finally developed to combine 1.0 kW RF power with a forced hot air heating at 50 °C, movement of the conveyor with the speed of 12.4 m/h, two mixings, and holding at 50 °C hot air for 5 min, followed by forced room air cooling through single-layer (2 cm thick) samples. There were no significant differences in quality parameters (moisture, protein, fat, starch, hardness, and color) between RF treatments and untreated controls during storage (P > 0.05). Therefore, RF treatments may provide a practical, effective and environmentally friendly method for disinfesting milled rice.     

Fate and efficiency of nitrogen fertilizers applied to wetland rice. II. Punjab,India

Two modified urea products (urea supergranules [USG] and sulfur-coated urea [SCU]) were compared with conventional urea and ammonium sulfate as sources of nitrogen (N), applied at 58 kg N ha^–1 and 116 kg N ha^–1, for lowland rice grown in an alkaline soil of low organic matter and light texture (Typic Ustipsamment) having a water percolation rate of 109 mm day^–1. The SCU and USG were applied at transplanting, and the whole dose of nitrogen was¹⁵N-labeled; the SCU was prepared in the laboratory and was not completely representative of commercial SCU. The SCU was broadcast and incorporated, whereas the USG was point-placed at a depth of 7–8 cm. The urea and ammonium sulfate applications were split: two-thirds was broadcast and incorporated at transplanting, and one-third was broadcast at panicle initiation. All fertilizers except the last one-third of the urea and ammonium sulfate were labeled with¹⁵N so that a fertilizer-N balance at flowering and maturity stages of the crop could be constructed and the magnitude of N loss assessed.At all harvests and N rates, rice recovered more¹⁵N from SCU than from the other sources. At maturity, the crop recovered 38 to 42% of the¹⁵N from SCU and only 23 to 31% of the¹⁵N from the conventional fertilizers, urea and ammonium sulfate, whose recovery rates were not significantly different. In contrast, less than 9% of the USG-N was utilized. Fertilizer nitrogen uptake was directly related to the yield response from the different sources. Most of the fertilizer N was taken up by the time the plants were flowering although recovery did increase up to maturity in some treatments.Analysis of the soil plus roots revealed that less than 1% of the added¹⁵N was in the mineral form. Between 20 and 30% of the¹⁵N applied as urea, SCU, and ammonium sulfate was recovered in the soil plus roots, mainly in the 0–15 cm soil layer. Only 16% of the¹⁵N applied as USG was recovered in the soil, and this¹⁵N was distributed throughout the soil profile to a depth of 70 cm, which was the lowest depth of sampling.Calculations of the¹⁵N balance showed that 46 to 50% of the urea and ammonium sulfate was unaccounted for and considered lost from the system. Only 27 to 38% of the¹⁵N applied as SCU was not recovered at maturity, but 78% of the USG application was unaccounted for. The extensive losses and poor plant recovery of USG at this site are discussed in relation to the high percolation rate, which is atypical of many ricegrowing areas.     

由稻壳提取高纯SiO2水热条件的研究

通过不同水热条件的研究提出由稻壳提取高纯ＳｉＯ２的合理途径，并且对它的粉体特征进行表征，并指出其可能应用途径。     

Effect of steam distillate extract of resistant wild riceOryza officinalis on behavior of brown planthopperNilaparvata lugens (Stal) (Homoptera: Delphacidae)

Rice plant volatiles extracted as steam distillates significantly affected the behavior of the brown planthopperNilaparvata lugens (Stal). In a choice test, significantly more females settled and fed on tillers of a susceptible rice variety, Taichung Native 1 (TN 1), sprayed with acetone or untreated TN 1 plants than on TN 1 tillers sprayed with the extracts of resistant wild riceOryza officinalis. O. officinalis steam distillate was highly toxic to first-instar nymphs ofN. lugens. Ingestion and assimilation of food by females was significantly reduced on TN 1 plants sprayed withO. officinalis distillate compared to TN 1 plants sprayed with acetone. Application of0. officinalis distillate on TN 1 plants adversely affected hatchability of eggs ofN. lugens.     

Acidity of oryzanol and its contribution to free fatty acids value in vegetable oils

Model oil systems containing physically refined rice bran oil to which oryzanol was added were examined to determine the effects of oryzanol concentration on FFA values. When oryzanol was added to the model oils at a 0.5% level and FFA was determined, increases in FFA value were 0.28% as determined with phenolphthalein, 0.58% with thymolphthalein, and 0.07% with alkali blue 6B. Oils containing added oryzanol at 0.5–1.5% showed a proportionate increase in FFA values with an average increase of 0.413% per gram of oryzanol. A direct titration of purified oryzanol showed an acidity of 42.5% expressed as FFA. In spectroscopic studies, the phenolic group in the ferulic acid moiety of oryzanol was titrated by sodium hydroxide. Based on these data, indicator correction factors for oryzanol's acidity and a formula for calculating real FFA content of vegetable oils containing oryzanol were developed.