Production of high-fructose rice syrup and high-protein rice flour from broken rice

The objective of this study was to develop a process for the production of both high-fructose rice syrup and high-protein rice flour from broken rice. The rice flour was obtained from broken rice by using either a dry or wet milling method. The glucose produced from the slurry of various raw materials by treating with α-amylase and glucoamylase was compared. Results indicated that cassava and corn starch were better raw materials than rice flour. However, the filtered residue of liquefied rice slurry could be recovered as high-protein rice flour. The particle size of rice flour had a small effect on the glucose yield. The orthogonal-array table (L₂₇) method of experimental design was employed to determine optimum conditions for liquefaction. The glucose yield based on starch was 90.8±3.6% under the following optimum conditions α-amylase, 0.12%; rice flour, 20%; temperature, 96°C; time, 90 min. The filtrate from liquefied rice slurry was saccharified at 60°C with three different concentrations of glucoamylase. The higher the enzyme concentration, the shorter the time required to reach the maximum yield. After saccharification, the glucose solution was decolourised, desalted and concentrated to 40% d.s. and then isomerised to fructose at 60°C under continuous operation by using immobilised glucose isomerase packed in a column. The isomerised syrup was then purified and concentrated to 71% d.s. The final high-fructose rice syrup contained 50% glucose, 42% fructose and 3% maltose. After liquefaction, the rice slurry was centrifuged and the precipitate was dried by either spray or drum drying. The composition of these two high-protein rice flours was almost the same and the protein content was about three times as high as the raw material. There were significant differences in surface structure of rice flour and high-protein rice flours, as observed by the scanning electron microscope.     

Structural properties of high-protein,low glycaemic index (GI) rice flour

Low glycaemic index (GI) rice flour was prepared by the enzymatic hydrolysis method. The protein content of treated (high-protein, low GI) rice flour was about 3.5 times higher than untreated rice flour, suggesting its use in infant formula or other protein-fortified food products. The GI of untreated and treated rice flour was found to be 88.0 ± 0.2 and 46.1 ± 0.2, respectively. High-protein, low-GI rice flour was studied for thermal and structural properties, which showed significant (p < 0.05) differences from untreated rice flour. The results of thermal properties showed a decrease in transition temperatures and enthalpy of gelatinization. The ratio of peaks at 1045 cm^?1 and 1015 cm^?1 of treated rice flour was significantly (p<0.05) lower than that of untreated rice flour. This could be ascribed to the loss of crystallinity due to enzymatic degradation. These results further support the decrease in transition temperatures and enthalpy of gelatinization. The results of the rheological studies of high-protein, low-GI rice flour revealed that both untreated and treated rice flour samples exhibited non-Newtonian shear-thinning flow behaviour (n < 1), which is characterized by a decrease in viscosity with an increase in shear rate.     

Weaning foods based on sesame protein

An attempt has been made to prepare seven weaning foods and two high-protein biscuits based on sesame protein. The evaluation of their chemical composition, amino acids, physical and sensory properties showed the successfull use of sesame flour in combination with dry skim milk and either corn or rice starch in preparing these types of food.     

HIGH-PROTEIN RICE-SOYA BREAKFAST CEREAL

The effect of three particle sizes and three different percentages of full-fat soya flour was studied for development of a high-protein rice-soya based reakfast cereal. Proximate analysis, essential amino acid profile, percentage water-holding capacity (WHC), crispiness and sensory evaluations were carried out for formulated flakes. The substitutions of 10, 20 and 30% full-fat soya flour for rice flour achieved good essential amino acid profiles but only the formuations with 20 and 30% soya flour qualified as high-protein flakes as reflected by their protein-calorie ratios (PCR) of approximately 15 and 19, respectively. The WHC of flakes was not affected by the percentage of soya flour used for the coarse (710 μm) and the medium (500 μm) particle size soya flour. The WHC of flakes formulated from fine (355 μm) particle size soya flour increased with the percentage of soya flour used. Crispness of flakes generally decreased with increasing percentage of soya flour at the 20 and 30% level. An inversely proportional relationship between crispiness and the particle size of soya flour was observed at the 30% level of substitution. Panelists did not show any trend in the overall preference of flakes developed.     

Physical Basis for Separation of Rice Starch using Various Density Gradient Systems and its Effect on Starch Recovery,Purity, and Pasting Properties

A 32% waxy and non waxy rice flour slurry containing starch‐protein agglomerates was physically disrupted in presence of water by use of high pressure homogenizer called Microfluidizer®. Microfluidized rice flour slurry from passes 2 and 4 was collected followed by isolation of starch using three different density gradient solutions/systems (CeCl, NaCl/sucrose and ZnSO₄·7H₂ O). Complete deagglomeration was obtained after passing the rice flour slurry four times through the Microfluidizer®. The recovery of isolated starch varied from 76.28% to 91.20% for different density gradient systems. The degree of deagglomeration did not seem to affect recovery but affected the purity of the isolated starches. All starches produced from pass 4 rice slurry resulted in starches with residual protein below 0.5%. Higher density of the gradient solution resulted in higher recovery and purity of starch. The isolation method had a significant effect on the pasting properties of the isolated starch. Residual protein in isolated starch had a negative correlation with peak viscosity and setback of pass 2 waxy and nonwaxy starches. The salts were retained in purified starch despite rigorous washing (at least 75 times greater than the control) and could affect starch properties.     

高蛋白大米粉中磷含量测定

采用GB5413．112010中钒钼酸铵显色法测定高蛋白大米粉中的磷，方法显色效果明显，线性好，灵敏度高。在波长为440nm条件下，分光度与磷浓度在110μg／mL范围内呈线性关系，检出限为0．223μg／mL，测定高蛋白大米粉中磷的计算标准偏差为0．744，相对偏差为0．67％，总回收率为95．2％。     

Zeta Potential (ζ) Analysis for the Determination of Protein Content in Rice Flour

Zeta potential (ζ) analysis was investigated as a means of rapid determination of residual protein content of rice flour during processing of rice starch. A rice flour sample was suspended in 0.3% sodium hydroxide solution to obtain rice flour slurry which was subjected to protein extraction by a decanter for five cycles. The samples from all cycles were collected, neutralized, dried, sieved through a 200 mesh sifter and subjected to ζ analysis. The data from ζ values (y) and chemical analysis of protein content (x) from six samples of rice flour were used in a regression analysis to develop an empirical equation to express the protein content of rice flour based on ζ value alone. The result of ζ value obtained from six samples of different protein contents suspended in a buffer solution of pH 12 yielded a standard linear equation of y = –1.29x–12.51. In another method of ζ analysis, the sample was suspended in DI (deionized) water without buffer by varying pH from 2 to 8 for the ζ measurement. A linear relationship between ζ and pH was obtained together with the constant value k (slope) which could be converted into protein content (x) of rice flour by a standard linear equation of k = –1.15x –4.90.     

广叶绣球菌菌丝体与子实体蛋白质营养价值评价

测定广叶绣球菌（Sparassis latifolia）子实体及不同配方液体培养基中菌丝体的蛋白质和氨基酸含量,采用国际通用的蛋白质营养评价方法对子实体和菌丝体的营养价值进行综合评价。不同液体培养基中菌丝体蛋白质含量为26.8%～30.6%,子实体蛋白质含量为13.4%;玉米粉配方菌丝体第一限制氨基酸为异亮氨酸,面粉、糯米粉配方第一限制氨基酸为含硫氨基酸（蛋氨酸＋胱氨酸）;子实体必需氨基酸含量为48.62%,高于各液体配方菌丝体,且子实体必需氨基酸指数、生物价最高。借助模糊识别法得出,玉米粉、面粉、糯米粉菌丝体与全鸡蛋蛋白质的贴近度分别为0.94、0.90和0.92,高于子实体。     

Mass Production Method for Rice Protein Isolate and Nutritional Evaluation

We developed a method for mass production of rice protein isolate (RPI) and evaluated its nutritional quality in rats. To obtain thick slurry, rice flour was mixed with a 0.6% Termamyl 120L-solution (1:2, w/v) at room temperature (～23°C). The slurry was heated at 97°C for 2 hr with stirring. Gelatinization and liquefaction occurred simultaneously. RPI obtained by filtration and washing with boiling water, was more than 90% pure protein (dry matter basis). It also contained 6.4% dietary fiber, 1.3% ash, and 1.1% carbohydrate. RPI diets (40–50%) allowed the maximum growth in rats comparable to that with 25% casein diet.     

Nutrient content and distribution in milling fractions of rice grain.

Nutrient content and distribution in a low-protein (7.5%) rice and a high-protein (10.8 %) rice were studied by analysing successive abrasive milling fractions of brown rice. Non-starch constituents decreased from the surface to the centre of the grain in both rices, except that the highest protein fraction in high-protein rice was the sub-aleurone layer. Starch and amylose contents of starch increased progressively from the surface to the centre of the grain and were lower in high-protein grain. Although this low-protein rice had lower total ash content than the high-protein rice, other samples of the same low-protein rice had comparable ash content to the high-protein rice. Glutelin accounted for 87–93% of milled rice protein. Protein and protein bodies of the sub-aleurone layer and inner endosperm have similar amino-grams, and electrophoretic patterns using analytical and SDS-polyacrylamide disc gels.     

婴儿营养米粉三种加工工艺及其对大米氨基酸的影响

本试验以大米为原料，研究了适合于婴幼儿生长需要的营养米粉的３种加工工艺，筛选出最佳工艺参数，分析了３种加工工艺对大米蛋白质氨基酸的影响，结果表明，膨化降低了大米蛋白质的氨基酸评分，酶解喷雾干燥及酶解冷冻干燥对其影响较小。本试验还对３种产品进行了表面电镜观察及淀粉变化程度的分析。     

高抗性淀粉大米对方便米粉品质及GI值的影响研究

为了开发低GI方便米粉满足糖尿病和超重/肥胖人群的饮食需求,研究高RS大米对方便米粉冲泡特性、质构特性、感官评分、微观结构及GI值的影响。结果表明,高RS的添加提高了方便米粉断条率与吐浆值,降低了感官评分值;方便米粉硬度、咀嚼性有所增加,粘性、弹性、回复性先增加后减少;提高了方便米粉中RS的含量,并使其GI值降低;通过SEM分析,高RS大米较普通大米制作的方便米粉剖面结构更具连续性,结构更为致密,孔洞明显减少;通过XRD分析,添加高RS大米的方便米粉样品在14°附近有一个特征峰,普通大米制作的样品没有。本文为低GI方便米粉的开发与生产实践提供新的思路,但高RS大米对方便米粉品质及GI值的影响机理还需要进一步研究。     

热变性大米蛋白的结构和性质研究Ⅰ米蛋白加热前后的溶解特性和氨基酸变化

为探讨热变性米蛋白的性质与结构关系,分析了大米蛋白加热前后的溶解性能和氨基酸组成变化。结果表明,米渣中各种蛋白质的含量大大低于未受高温处理的原料大米;米渣蛋白中胱氨酸含量比大米谷蛋白提高83%,说明大米醇溶蛋白、球蛋白和清蛋白等受热后也存在于米渣中;米渣谷蛋白胱氨酸含量比米渣蛋白降低23%,说明胱氨酸是影响米渣蛋白溶解的重要因素。     

Consumer acceptance of an extruded soy-based high-protein breakfast cereal

ABSTRACT:  Studies have shown the beneficial effects of soy and high-protein diets on weight loss. The objective of this study was to determine consumer acceptance of a soy-based high-protein breakfast cereal developed to be utilized for weight loss and control. Four formulations with soy flour content of 41%, 47%, 54%, and 60% (w/w) were processed by extrusion. The formulations met the Food and Drug Administration (FDA) guidelines to claim the role of soy protein in reducing the risk of cardiovascular diseases and guidelines for high-protein and high-fiber foods. The effects of soy flour level, addition of cinnamon flavor, and evaluation with or without milk on acceptance were investigated. Overall acceptance of 3 of 8 cereal products was also compared to the acceptance of 5 commercial products in the "healthy" cereal category. Addition of up to 54% (w/w) soy flour resulted in comparable acceptance ratings to products with lower soy flour content. Addition of milk improved aroma and texture acceptance scores and addition of cinnamon flavor improved overall, aroma, and taste acceptance scores. Acceptance of the developed cereal products was not as high as the commercial products; however, it significantly increased when nutritional and cost information was presented. The results of this study demonstrated that with modification of the formulations, an acceptable high-protein soy-based cereal can be developed to increase protein consumption during breakfast meals, which can consequently aid in weight loss and control.     

大米分离蛋白的酶法提取及其性质

本文研究了以糖渣为原料,用淀粉酶法水解法制备大米分离蛋白(E-RPI)的反应条件,并测定了蛋白质的溶解性、乳化性及其氨基酸组成。结果表明,反应中固液比为1:12.96、加酶量为0.096％、反应时间为2.3h时效果最好,使糖溶出量达到原料重量的25.7％,产物中的蛋白含量为88.6％,回收率为90.5％;E-RPI的乳化活性随pH值的升高而增大,与大豆蛋白相比,乳化活性低而稳定性高。E-RPI中除赖氨酸外,其它必需氨基酸的含量均高于大豆蛋白和酪蛋白。     

Effect of Levilactobacillus brevis TISTR 860 and Lactiplantibacillus plantarum TISTR 951 on gamma-aminobutyric acid content in fermented rice flour and rice noodles (Kanomjeen)

This research aimed to reduce the fermentation time of fermented rice flour for fermented rice noodles (Kanomjeen) to 24 h by adding the initial starter cultures, which are Levilactobacillus brevis TISTR 860 (LB) and Lactiplantibacillus plantarum TISTR 951 (LP) alone in rice slurry to achieve the quality and high gamma-aminobutyric acid (GABA) content. The initial pH value of rice slurry was adjusted to 4.5 and enriched with 2% of monosodium glutamate (MSG) before fermentation. LP was able to produce lactic acid and reduced pH better than LB but produced GABA in less content. Expanding fermentation time induced decreasing in viscosity and whiteness of flour. Fermented rice noodles provided better tensile strength and elasticity. In conclusion, LB could produce GABA in the amount of 21.80 mg/100 g dry basis in 24 h with good quality.     

ON VISCOGRAMS AND VISCOGRAPHY, WITH SPECIAL REFERENCE TO RICE FLOUR

Brabender viscograms are usually determined at an arbitrarily fixed starch (or flour) slurry concentration and the resulting peak viscosity (P), breakdown (BD) and setback (SB) values are used as criteria for starch characterization. However, the use of this technique in rice quality research has not been fruitful. A critical review of some of the literature on viscography uncovered a number of fallacies in the above technique. It was revealed that even in a given sample, the magnitude of BD and SB varied drastically with the peak viscosity obtained, which in turn varied exponentially with the slurry concentration. In several samples of rice flour studied, it was found that not only the magnitudes of BD and SB but even the algebraic sign of SB depended on the slurry concentration chosen. Clearly, viscogram parameters of different samples can be properly compared not at a fixed slurry concentration but only at a fixed peak viscosity. Values of a few ratios at a fixed P value, particularly that of relative breakdown (BD_r= BD/(BD + SB)), could effectively differentiate between starch and rice types.     

SLURRY VISCOSITY AS A POSSIBLE INDICATOR OF RICE QUALITY

Forty-one rice varieties belonging to eight quality types were examined. The viscosity of a 5% rice flour slurry dispersed in 2% carboxymethylcellulose, measured with an Ostwald capillary viscometer, was remarkably constant among varieties within the same quality type but increased significantly from type I (high-amylose) through type VIII (little or no amylose) rice. Slurry viscosity was strongly affected by particle size, being higher for finer flour, but it appeared independent of the age of the rice after harvest. Slurry, as well as paste viscosity, was affected by kernel chalkiness in rice, chalky grains showing lower viscosity than vitreous grains. Chalky rice grains contained less amylose and hydrated more in ambient water than nonchalky ones. When ground under a constant condition, high-amylose rice yielded slightly coarser flour than intermediate- or low-amylose rice, suggesting differences in grain hardness.     

Effects of japonica rice flour on the mesoscopic and microscopic properties of wheat dough protein

The aim of this study was to study the effects of twelve varieties of japonica rice flour on the gluten protein composition and structure of wheat dough. Experimental results indicated that the addition of japonica rice flour significantly decreased the α-helix structure in the gluten protein sample, but increased the random coil content, indicating that the protein secondary structure became more disordered. The ratio of α-helix/β-sheet structures in the dough supplemented with different varieties of japonica rice flour was decreased, contributing to improved dough stability. Increasing the proportion of japonica rice flour from 10% to 40% significantly decreased the sulfhydryl content of the mixed flour dough. However, the total sulfhydryl content was only positively correlated with the amount of Longdao 19 japonica rice flour, reaching a maximum of 25.34 mol g⁻¹ at 40% japonica rice flour. The gluten structure of mixed flour dough typically forms a porous three-dimensional network, with the Longdao 19, 20, 23 and 25, Longjing 31 and Mudanjiang 31 japonica rice flours leading to improved gluten protein networks. In summary, the supplementation of standard wheat flour with japonica rice flour can alter dough properties and gluten structure.     

Development of weaning food formulations based on malting and roller drying of sorghum and cowpea

Sorghum and cowpea were steeped in water for 16 h, allowed to germinate for 72 and 24 h respectively, then dried to about 14% moisture. Roots and shoots of sorghum sprouts were cleaned off and the devegetated malt was kilned at 70°C, moistened with 3% added water, heaped for about 10 min, milled and sieved to obtain debranned malt flour. Cowpea sprouts were split, dehusked, kilned at 85°C and milled. Malted sorghum and malted cowpea flours were blended in the proportion of 70:30 to prepare the malted weaning food (MWF). A precooked weaning food (RDF) was prepared by roller drying a cold water slurry consisting of 70% pearled sorghum flour and 30% toasted cowpea flour. The cooked paste viscosity of MWF was considerably lower than that of RDF and the blend of raw sorghum (70%) and cowpea (30%), at all comparable slurry concentrations. The protein content of MWF was 13.4% and that of RDF was 13.0%, but the available lysine content of MWF protein was 3.85% and that of RDF protein was 2.95%. The protein efficiency ratio for MWF (2.26) was significantly higher than that for RDF (1.87).