Peanut as a source of protein for human foods

Peanut has traditionally been used as a source, of oil; however, its worldwide annual protein harvest has reached nearly 4.5 million tons. India followed by China and the United States are the major producers of peanut. In recent years, several cereals and legumes-based foods using peanuts as protein supplements have been developed to alleviate protein caloriesmalnutrition problem. Peanut in the form of flour, protein isolates, and meal in a mixed product have been found to be very desirable from a sensory quality point of view. Peanut protein is deficient with respect to certain essential amino acids, but its true digestibility is comparable with that of animal protein. Even though various processing methods influence the nutritional and sensory quality of peanut fortified human foods available information on these aspects have been reviewed and summarised in this paper in order to optimize the utilization of peanut protein to increase protein value of cereal-based foods in developing countries of the peanut growing regions, of the world.     

Protein and lysine digestibility and protein quality of cooked Filipino rice diets and milled rice in growing rats

The protein quality of typical rice-based menu of Filipino preschool child and adult and cooked milled rice was assessed for true digestibility (TD), biological value (BV) and net protein utilization (NPU) in growing rats. Lysine and energy digestibilities were also determined. For the preschool child diet, TD was 88.8%, BV 90.0%, and NPU 79.9%. For the adult diet, TD was 87.3%, BV 86.6%, and NPU 75.5%, whereas cooked rice had 90.0% TD, 82.5% BV and 74.3% NPU. Lysine digestibility was 95.4% for preschool child diet, 95.7% for adult diet, and 100.0% for rice. Digestible energy was 91.3% for preschool child diet, 93.0% for adult diet, and 95.3% in rice. Amino acid scores were 100.0% for preschooler diet, 92.1% for adult diet, and 62.2% for rice. Protein quality based on amino acid score corrected for TD was 88.8% for preschool child diet. 80.4% for adult diet, and 56.0% for rice. If based on lysine digestibility instead of TD, protein quality would be 7.1% higher.     

Evaluation of the protein quality of rice supplemented with bean or crayfish in rats

Weanling male rats (45–60 g) were used to compare the supplemental effects to rice protein of bean or crayfish protein. Rats were fed various combinations of rice plus bean (B) or crayfish (C) to provide 1.6 g N/100 g of the daily diet for 28-day growth studies and a 7-day N balance period. Five different diets were fed. Six rats were assigned to each diet on the basis of body weight. Combinations of R:B of 80:20 and of R:C of 80:20 produced food intake, weight gain, PER, N intake, digested and retained N; and liver weight values that were comparable. However, increasing C to 30% of the dietary protein led to reduced value for food intake, weight gain, PER, N intake, digested and retained N, BV, NPU, and liver weight when compared with values obtained when B was increased to 30% (P<0.05). The results appear to indicate that, above a certain level of supplementation, brown bean protein is superior to crayfish as a supplement to rice protein.     

Properties of poorly digestible fraction of protein bodies of cooked milled rice

Pepsin-treated protein bodies and human fecal protein particles from IR480-5-9 cooked milled rice (Oryza sativa L.) consisted mainly of giutelin-type polypeptides with a mean molecular weight (MW) of 16 000. They had similar MW, amino acid pattern, and isoelectric focusing characteristics as the 70% 2-propanol—0.6% -mercaptoethanol soluble fraction of rice glutelin. The lipids of the pepsin-treated protein bodies had an identical lipid fraction ratio and fatty acid composition as the lipids of whole protein bodies.     

水稻DnaJ蛋白的生物信息学分析

DnaJ蛋白是一类很大的蛋白家族,因含有保守的DnaJ结构域而得名。本文对水稻DnaJ蛋白进行了生物信息学分析表明,水稻中共有101个DnaJ蛋白,分为典型的三大类。通过表达证据搜索发现,除了11个基因没有表达证据外,其他基因在水稻中都有表达。此外,对水稻的DnaJ蛋白家族进行了初步的进化分析。     

Effect of treatment on composition and protein and energy utilization of rice and mung bean by rats

Yellow rice derived from stack-burned unthreshed grains had lower lysine content than white milled rice. Stack burning did not affect energy digestibility in growing rats but decreased true nitrogen digestibility and net protein utilization (NPU). Increasing parboiling time from 20 to 60 min had no adverse effect on energy and protein utilization of parboiled milled rice. Defatting of rice bran-polish with petroleum ether at 50°C had no effect on protein utilization but decreased energy content and utilization. Mechanical dehulling of mung bean (Vigna radiata [L.] Wilczek) reduced fiber content, increased energy and protein digestibility but decreased biological value (BV) and NPU. Toasting and winnowing the bean reduced lysine content, improved digestible energy but decreased BV and NPU. Cooking the bean preparations improved the biological value only in mechanically dehulled bean with resultant higher NPU than that of whole bean.     

Changes in the properties of rice varieties with different amylose content on dry heat parboiling

Dry heat parboiling is a unique paddy processing technique that has been scarcely exploited. Dry heat parboiling at high temperature for short time and low temperature for long time on physical and physicochemical properties of three rice varieties differing in amylose content were studied. Hardness of the kernels increased from 66.4 N, 68.8 N and 59.8 N in raw samples to 89.1 N, 86.9 N and 59.8 N in parboiled high amylose, low amylose and waxy rice samples respectively. Rapid migration and evaporation of water from severely heated kernels caused cavity formation at the centre. Irreversible damage of amylopectin structures to leachable fractions caused continuous rise of the pasting curve. Crystallinity was thereby reduced. Parboiled high amylose samples gave X-ray diffraction patterns with peaks characteristic of A, B and V-type starch crystallinity. Crystalline starch-lipid complexes were observed in low amylose and waxy rices. The significant increase in the amount of rapidly digestible starch from 56.7%, 61.7% and 66.6% in raw samples to 92.1%, 90.8% and 94.8% respectively in severely processed rice samples and subsequent reduction in resistant starch from 24.5%, 21.2% and 18.4% to 0.4%, 1.9% and 0.1% indicated possibilities for targeted food use of the dry heat parboiled samples.     

Evaluation of rice as unregulated hidden allergen by fast real-time PCR

1. Download : Download high-res image (112KB)
2. Download : Download full-size image

     

Effect of high protein rice on nitrogen retention and growth of preschool children on a rice-based diet

The effect of high protein milled rices (IR480-5-9 and IR2153-338-3, 10% protein) on the nitrogen retention and growth of preschool Indian children was assessed in two feeding trials in a residential home. The children were offered, ad libitum, a rice-based diet in four meals daily without vitamin and mineral supplement. The children in the experimental group were given the high protein rice; those in the control group were given a local rice (7% protein). The groups had similar percent apparent digestibility and retention of dietary nitrogen. Statistically significant differences in increase in height and weight between the two groups were not consistently observed at the end of 4.5 to 5 months or 1 year. Possible factors contributing to these results are discussed.     

低温对粳稻光温敏核不育系育性影响研究

籍2004年盛夏难得的14-16℃低温条件,对两系杂交水稻不育系在自然低温下的育性进行跟踪研究结果表明,低温能导致花粉不育度的明显降低,而且14-16℃的低温,不仅能使花粉不育度降低,而且还能诱导一定程度的自交结实;育性温度敏感期为幼穗分化第四期(雌雄蕊形成期至花粉母细胞形成期);在相同低温的条件下,短日处理的光温敏核不育系的不育度大大降低。对低温不敏感的不育系 G103,在短光作用下败育也较彻底。对短光不敏感的不育系是理想的不育系。不同株系间在低温下育性表达存在显著差异,且在自然短日低温务件下,这种差异更加明显。     

Effects of nitrogen fertilizer treatment and source and season on grain quality of IR64 rice

The effects of nitrogen fertilizer treatment and source (prilled urea, urea supergranule, fresh azolla, rice straw or sesbania or rice straw compost and their combinations) on grain quality were studied in the 1987 crops of variety IR64 at IRRI. Although fertilizer application improved grain yield, it improved protein content only in the case of urea supergranule, azolla and rice straw. Lysine contents of brown rice protein were similar in samples with no N fertilizer and those with the highest protein content in both seasons. Fertilizer treatment regardless of source tended to decrease weight and increase translucency of brown rice in both seasons. Effects on other grain properties were not consistent in both seasons. Season affected more grain properties than fertilizer treatment did, particularly translucency which was higher in the dry season than in the wet season.     

Protein and energy utilization of rice milling fractions by rats

Brown rice (variety IR32), bran, and polish had higher protein content and lysine content in protein than milled rice. Nitrogen balance in growing rats showed that brown rice had lower true digestibility, but similar biological value and NPU as milled rice. Undermilled rice had similar true digestibility, but higher biological value and NPU than milled rice. Bran and polish had lower true digestibility, but higher biological value than brown and milled rice, but polish had higher NPU than bran and the three other milling fractions. The percentage of digestible energy in the rats was lowest for bran.     

Differences in functional properties and biochemical characteristics of congenetic rice proteins

Proteins in brown rice (BR), white rice (WR) and rice bran (RB) were extracted from the same paddy rice and investigated for their components, functional properties and chemical characteristics by SDS-PAGE methodology. BR and WR proteins possessed a poor solubility under weak acid conditions due to a high content of glutenin and richness in higher molecular-weight (MW) protein fractions. Rice bran protein contained significantly lower molecular-weight components (MWs < 50 kDa) than those in WR and BR. Nitrogen solubility, foaming and emulsification properties of their rice protein preparations were affected not only by pH (3–11), but also by the concentrations of NaCl (0.4–2.0%) and sucrose (4.0–20.0%). All of them, particularly rice bran protein, had favorable functional properties in the medium with a high salt or sugar concentration. Therefore, they have a good potential for development in the food industry.     

低温胁迫下小麦幼穗中差异表达蛋白质的鉴定

为探究低温胁迫下小麦幼穗中胁迫响应差异表达蛋白,采用IEF/SDS-PAGE双向凝胶电泳及质谱技术,以低温敏感品种SW601和低温不敏感品种陇麦157为材料,对常温生长、0℃低温胁迫12h和72h的幼穗全蛋白进行了分析。结果表明,在pH 4~7时,SW601和陇麦157各处理幼穗蛋白图谱中均可重复检测到800~900个有效蛋白质点;低温胁迫12h、72h后,SW601和陇麦157中上调表达的蛋白点分别有120个和101个,下调表达的蛋白点分别有92个和60个。对2种胁迫处理下均差异表达且Ratio2的54个蛋白点进行质谱分析,成功鉴定出43个差异蛋白。经数据库搜索匹配和蛋白质鉴定,这43个差异蛋白分别属于胁迫应激/防御相关蛋白、光合作用蛋白、蛋白代谢相关蛋白、碳水化合物代谢相关蛋白、信号传导相关蛋白、能量产生和运输相关蛋白和未知功能蛋白等7类蛋白。其中,抗坏血酸过氧化物酶、Cu/Zn超氧化物歧化酶和胚胎后期发育富集(LEA)同源蛋白14-A等蛋白的表达量在低温不敏感材料陇麦157中变化显著,而在低温敏感材料SW601中没有表达,这可能与小麦幼穗在低温逆境下的代谢调控和低温敏感特性有一定关系。     

Characterisation and functional properties of Australian rice protein isolates

Albumin, globulin, glutelin and prolamin fractions were isolated from an Australian rice variety (cv. Langi) and characterised by yield, protein content and molecular weight profile using both capillary electrophoresis (SDS-CE) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The influence of pre-extraction enzymatic hydrolysis of starch and heating to 70 °C was also investigated, as was the extraction of the glutelin fraction without prior removal of the albumin and globulin fractions. Pre-extraction treatment affected mainly the albumin fraction, increasing dry matter yield but reducing protein content. SDS-CE was able to separate the protein fractions over a wider molecular weight range than SDS-PAGE, and the peaks from SDS-CE showed slightly higher molecular weight compared to equivalent bands from SDS-PAGE. The glutelin fraction extracted without prior removal of albumin and globulin fractions had different characteristics compared to those obtained by conventional extraction methods. Pre-extraction hydrolysis of starch did not significantly affect the emulsifying, foaming and gelling properties of extracted protein. Although rice glutelin had poor solubility, emulsifying and foaming properties in aqueous systems, it had good gelling properties which could be important for food applications.     

The nutritional components and physicochemical properties of brown rice flour ground by a novel low temperature impact mill

A low temperature impact mill (LTIM) was created and used for grinding brown rice. The nutritional components and physicochemical properties of the resulting flour were investigated and compared with those ground by traditional wet colloid mill (CM) and dry high-speed universal grinder (HUG). It was found that LTIM produced a fine flour with unimodal particle size distribution, and well retained non-starch nutrients. Especially, the phenolic content of flour prepared by LTIM was two times higher than that prepared by CM. LTIM also led to less damaged starch content than HUG. The damaged starch content related well with the thermal and gel hydration properties. Interesting, comparing the particle size distribution before and after enzymolysis, it was found that LTIM could pulverize dietary fiber of brown rice efficiently. The results from this study indicated that the LTIM may provide a promising technology for pulverizing brown rice thus open its new applications.     

杂交稻新恢复系主要农艺性状的配合力分析

利用5个三系杂交稻不育系（金山2A、福伊A、京福5A、G201A、太香A）和5个杂交稻恢复系（22、制3、404、制6、明恢86）,通过不完全双列杂交配置了25个杂交稻组合,研究了这些新恢复系14个主要农艺性状的配合力。结果表明,14个主要农艺性状的一般配合力方差与特殊配合力方差均达显著或极显著差异水平,并且一般配合力方差明显大于特殊配合力方差,说明杂交稻主要农艺性状的遗传以加性效应为主。除有效穗和播始历期外,父本和母本对株高、穗长、穗颈长、剑叶长、剑叶宽、倒二叶、倒三叶、一次枝梗、二次枝梗、穗粒数、千粒重和结实率等12个农艺性状具有同等重要作用。杂交稻亲本的一般配合力和组合的特殊配合力是相互独立的,相同性状的亲本一般配合力和组合的特殊配合力效应不同,因此组合的特殊配合力是关键。制3、制6、404是一般配合力较好的恢复系,它们的杂种综合性状都比较好,是具有较好育种应用前景的恢复系。     

Sesame oleosin and prepro-2S albumin expressed as a fusion polypeptide in transgenic rice were split, processed and separately assembled into oil bodies and protein bodies

A recombinant polypeptide containing the precursor protein of a sesame storage protein, 2S albumin, fused to the C-terminus of a sesame oleosin was expressed in transgenic rice seeds under the control of a rice glutelin promoter. The recombinant polypeptide of 32 kDa, equivalent to the resultant molecular mass of sesame oleosin (15 kDa) and prepro-2S albumin (17 kDa), was detected in the endoplasmic reticulum fraction of maturing transgenic rice seeds, but not in the purified oil bodies or the soluble extract of transgenic seeds. However, sesame oleosin presumably fused with a 2 kDa C-terminal appendix originating from the signal sequence of prepro-2S albumin, was found in the purified oil bodies, and mature sesame 2S albumin apparently processed into two subunits (9 and 4 kDa) linked by disulfide bonds was detected in extracts of transgenic seeds. Immunogold labeling revealed that the sesame oleosin and 2S albumin were separately located in oil bodies and protein bodies of embryo cells of transgenic rice seeds. While sesame 2S albumin was also detected in protein bodies of endosperm cells of transgenic seeds, the co-expressed sesame oleosin, probably degraded due to the lack of oil bodies in this tissue, and was not detected. The results provide a new technique for introducing two recombinant polypeptides separately into rice oil bodies and protein bodies from one expression construct.     

Microstructure and rheological properties of mixtures of acid-deamidated rice protein and dextran

Microstructure and rheological properties of mixtures of acid-deamidated rice protein (ADRP) and dextran were studied. The microstructures of the ADRP/dextran mixtures were described using confocal laser scanning microscopy (CLSM), which revealed the effective association among ADRP and formation of a protein network-like structure in the mixture with higher protein concentration. Mechanical properties of the mixtures were observed by rheometer. The steady shear measurements showed a correlation with the CLSM results via a marked increase in the viscosity of the mixtures with protein association. Frequency sweeps further evidenced the build-up of the gelled network-like structure. The differences in fracture forces observed by textural measurements between mixture and single ADRP gel also suggested the difference in microstructures. The formation of network-like structure appeared to have occurred through a phase separation of ADRP and dextran.     

Protein requirements of preschool children consuming rice-milk,rice-toasted mung bean,and rice diets

Rice-milk and rice-toasted mung bean diets, and a high-protein rice (IR58 milled rice) were evaluated as part of a study on the protein requirements of toddlers consuming rice-based diets following the multilevel N balance method. Milk or mung bean contributed 1/3 of dietary N. At a daily energy intake of 418 kJ/kg body weight, weight losses were observed for all diets. The safe level of protein intakes obtained allowing 10 mg N/kg body weight/day for miscellaneous integumental losses and 15 mg N/kg body weight/day for growth was 1.11 g/kg body weight/day for the rice-milk diet and 1.34 g for the rice-mung bean diet. Preliminary data on four children indicate a safe level of protein intake of 1.44 g/kg/day for the IR58 milled rice. The protein quality of the high-protein rice as determined by the very short term N balance index on three children was 79–80% relative to milk.