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1.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

2.
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

3.
Surveys were undertaken in six districts of southwestern Ethiopia from July to October 2003 to investigate farmers’ perceptions and management practices of insect pests on traditionally stored sorghum. The survey involved 138 randomly selected farmers who were interviewed using a semi-structured questionnaire. Storage insect pests were perceived as the major insect pests of sorghum. The majority of the farmers estimated sorghum yield losses of up to 50% due to insect damage during storage. High temperature and lack of storage hygiene were cited as the major factors resulting in insect infestation of stored sorghum. Infestations of stored sorghum insect pests were common on different forms of sorghum, which stored in various types of farm storage. Farmers classified sorghum varieties according to the level of resistance to stored sorghum insect pests. Only about 32% of the farmers had access to chemical insecticides for the control of stored sorghum insect pests, while the majority of them used cultural practices and locally available plant materials as storage protectants.  相似文献   

4.
This review deals with the biochemical basis and implications of hardness and grain strength in sorghum and maize. Grain hardness affects various aspects of the growth and processing of cereal grain from resistance to fungal infection to cooking quality. It is clear that the prolamins play an important role with the γ-prolamins being the most important. It would appear that these prolamins help shape the protein bodies and form disulphide bonds within themselves or with other proteins. The γ-prolamins form the cement while the α-prolamins are the bricks. Both prolamins are present in greater proportions in hard grains and in the vitreous portion of hard grains. Genetic and environmental effects on the amounts of the different prolamins and on their distributions within the protein body and in different parts of the endosperm also determine grain hardness. Grains that will be hard appear to deposit prolamins and antifungal proteins earlier and in greater amount than do soft grains. The cell wall composition is also different between the two types of grains while there is a higher proportions of amylose in the starch of hard than in that of soft grains. Most of the differences that exist between hard and soft grains also exist between the outer and inner portion of the grain. It is postulated that there might be a master gene controlling the onset of strength in grains by simultaneously altering the levels of various apparently unrelated biochemical events. It is also suggested that solute availability may play an important role in the regulation of expression of genes for hardness-related proteins.  相似文献   

5.
Farmers and grain traders in sub-Saharan Africa are forced to sell stored produce prematurely because of deterioration due mostly to insect damage. Producers expressed a need for a relatively cheap and safe method of insect control. Diatomaceous earths (DE) offer safer alternatives to synthetic chemicals, but information on their efficacy under tropical small-scale farming conditions is lacking. Two commercially available DE products, Protect-It® and Dryacide®, were tested against the major post-harvest insect pests of grains and pulses. On-farm field trials in Zimbabwe showed that both inert dusts gave significant protection against insect damage when admixed with farm stored maize, sorghum and cowpeas for periods of 40 weeks. However, efficacy of these DEs is closely linked to the application rates and differs between commodities, locations and insect pests. An admixture application rate of 0.1% w/w of Protect-It® or Dryacide® can be recommended to protect both maize and cowpea grain that is to be stored for 4 months or longer in Zimbabwe. However, Dryacide® was not effective in preventing damage to sorghum grain by the bostrichid Rhyzopertha dominica unless applied at a higher rate of 0.2% w/w.  相似文献   

6.
盐碱地适盐种植是目前发展盐碱地产业的重要模式。以3个酿酒高粱品种为研究对象,通过测定并分析酿酒高粱的农艺性状、产量及籽粒品质等指标,筛选出耐盐、优质高产的酿酒高粱品种以丰富河套灌区作物的种植结构,降低因长年种植葵花引起各种病虫害的发生,并提供优质酿酒原料。研究结果表明:1)吉杂127的产量最高,为10 832.0 kg/hm^2,其次是辽杂19的10 429.8 kg/hm^2;2)辽杂19农艺性状、产量及籽粒淀粉、蛋白质含量和容重等指标优于其他品种,为最佳酿酒高粱品种;3)相比于种植葵花,种植高粱具有机械化程度高、便于轮作倒茬等优点,提高种植户的净收入约5070元/hm^2,并能提供优质酿酒原材料。  相似文献   

7.
近年研究发现,一些虫生真菌在自然界中具有双重寄主,不仅可以寄生在昆虫中,还可以定殖在植株中。虫生真菌在植物中定殖,既能促进植物生长,又能提高寄主植物抗性,这种独特的生态学功能,有助于更好地在植物保护中发挥作用。本文综述内生性虫生真菌在植物中的定殖特性及这种定殖特性对害虫和植物病原体的间接控制效果,探讨虫生真菌植物内生性及其提高寄主植株对病虫害抗性的作用机理,提出虫生真菌作为双重生防治剂的可能性和未来的研究方向。  相似文献   

8.
Use of pesticides, herbicides and fertilizers is among the techniques to control insect pests and fungal pathogens. However, the technique is the major contributor to severe environmental implications in terms of air, water and soil pollution. Besides, variable inconsistency becomes an important issue in the implementation of inclined bed dryers, leading to significant rice grain loss. Cold plasma technology has been widely proposed as a potential alternative for rice grain postharvest treatment management due to the presence of generated ionised gas that eventually produces reactive oxygen species or reactive nitrogen species. These species are used to decontaminate foodborne pathogens, mycotoxins and bacterial diseases. This review explores the current literature regarding cold plasma treatment technology, focusing on its efficiency as the microbial decontamination medium and insect pest mortality medium, and on the enhancement functional, nutritional and cooking properties, especially in rice grains. Previous studies have successfully demonstrated the ability of cold plasma treatment to significantly reduce the microbial count of foodborne pathogens, detoxify mycotoxins, and control seedborne rice seedling bacterial diseases. Previous studies have also proved that the implementation of cold plasma technology in postharvest management should be seriously considered for improving rice grain quantity and quality in Malaysia.  相似文献   

9.
国内外优异高粱种质资源的综合评价   总被引:2,自引:0,他引:2  
对“八五”、“九五”期间收集到的820份国内外高粱品种资源进行农艺性状、抗病虫、抗逆性筛选鉴定及综合评价。试验表明,有一批矮秆、大穗、大粒、抗或多抗性的资源,可作为育种的基础材料,供资源创新、改良现有品种的品质、抗性等选择利用。  相似文献   

10.
There is considerable interest in sorghum, millets and pseudocereals for their phytochemical content, their nutritional potential and their use in gluten-free products. They are generally rich in a several phenolic phytochemicals. Research has indicated that the phenolics in these grains may have several important health-promoting properties: prevention and reduction of oxidative stress, anti-cancer, anti-diabetic, anti-inflammatory, anti-hypertensive and cardiovascular disease prevention. However, increased research on the actual health-promoting properties of foods made from these grains is required. Biofortified (macro and micronutrient enhanced) sorghum and millets are being developed through conventional breeding and recombinant DNA technology to combat malnutrition in developing countries. Enhanced nutritional traits include: high amylopectin, high lysine, improved protein digestibility, provitamin A rich, high iron and zinc, and improved mineral bioavailability through phytate reduction. Some of these biofortified cereals also have good agronomic characteristics and useful commercial end-use attributes, which will be important to their adoption by farmers. Knowledge of the structure of their storage proteins is increasing. Drawing on research concerning maize zein, which shows that it can produce a visco-elastic wheat-like dough, it appears that the storage proteins of these minor grains also have this potential. Manipulation of protein β-sheet structure seems critical in this regard.  相似文献   

11.
Although a principal source of energy and protein for millions of the world's poorest people, the nutritional value of sorghum (Sorghum bicolor L. Moench) is diminished because of low digestibility of grain protein and starch. To address this problem, we analyzed the properties of two sorghum lines that have a common pedigree but differ in digestibility. Consistent with results based on a ruminal fluid assay, the protein and starch of one line (KS48) was more thoroughly digested than that of the other (KS51) using in vitro assays based on pepsin and α-amylase. The indigestibility of KS51 relative to KS48 was shown to be due to (i) a greater abundance of disulfide-bonded proteins; (ii) presence in KS51 of non-waxy starch and the accompanying granule-bound starch synthase; and (iii) the differing nature of the protein matrix and its interaction with starch. The current findings suggest that each of these factors should be considered in efforts to enhance the nutritional value of sorghum grain.  相似文献   

12.
Traditional storage practices in developing countries cannot guarantee protection against major storage pests of staple food crops like maize, leading to 20-30% grain losses, particularly due to post-harvest insect pests and grain pathogens. As a result, smallholder farmers end up selling their grain soon after harvest, only to buy it back at an expensive price just a few months after harvest, falling in a poverty trap. The potential impact on poverty reduction and greater livelihood security will not be realized, however, if farmers are unable to store grains and sell surplus production at attractive prices. Apart from causing quantitative losses, pests in stored grain are also linked to aflatoxin contamination and poisoning. To address this problem, a metal silo was developed as a valid option and proven effective in protecting stored grains from attack by storage insect pests. A metal silo is a cylindrical structure, constructed from a galvanized iron sheet and hermetically sealed, killing any insect pests that may be present. The impact of metal silo technology in Africa, Asia and Latin America includes, improving food security, empowering smallholder farmers, enhancing income opportunities and job creation, and safeguarding the agro-ecosystems. The metal silo can be fabricated in different sizes, 100 kg-3000 kg holding capacity by trained local artisans, with the corresponding prices of $35 to $375. The use of metal silo, therefore, should be encouraged in order to prevent storage losses and enhance food security in developing countries.  相似文献   

13.
Insect pests are a key constraint to effective utilization of cereal crops in sub-Saharan Africa (SSA), with damage caused by these pests in the stores of particular concern. Although a number of approaches have been advanced for control of storage pests of maize, uptake remains a challenge, with effectiveness of some approaches being questionable. We conducted a survey in western Kenya among 330 respondents using face to face interviews and focus group discussions to evaluate farmers' practices, knowledge and perceptions of storage pests of maize, and their current practices in managing such pests as a basis for development of efficient integrated pest management (IPM) approaches for the pests. Majority of the respondents stored maize in traditional granaries, with less than 10% of them using modern improved facilities, mainly due to inability to afford these. Majority of the respondents also cited attack of their stored grains by a number of insect pests, causing about 40% grain losses. The larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), sawtoothed grain beetle, Oryzaephilus surinamensis (L) (Coleoptera: Silvanidae), and maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), were perceived as the most common and damaging pests. Farmers' perceptions of pests were positively and significantly influenced by level of education and farming experience, indicating that education and experience build farmers' understanding of storage pests. Storing maize in unshelled form seemed to result in less pest attack, although majority of the respondents stored their maize in shelled form. Moreover, local maize varieties were perceived to be resistant to pests. The farmers applied various control methods, with sun-drying being the most popular practice. Usage of pesticides was minimal, mainly due to high costs, lack of information, and unavailability of appropriate and effective products. There were also other cultural methods applied, such as use of smoke and insecticidal plants. The respondents decried lack of training and extension services on storage pests and their management, underscoring the need to develop extension services. The underlying mechanisms of the perceived pest resistance in local varieties of maize and cultural pest management methods need to be established for exploitation in development of effective IPM approaches. There is also need to address the challenges hindering uptake of modern storage and control approaches.  相似文献   

14.
Chitin deacetylases, occurring in marine bacteria, several fungi and a few insects, catalyze the deacetylation of chitin, a structural biopolymer found in countless forms of marine life, fungal cell and spore walls as well as insect cuticle and peritrophic matrices. The deacetylases recognize a sequence of four GlcNAc units in the substrate, one of which undergoes deacetylation: the resulting chitosan has a more regular deacetylation pattern than a chitosan treated with hot NaOH. Nevertheless plain chitin is a poor substrate, but glycolated, reprecipitated or depolymerized chitins are good ones. The marine Vibrio sp. colonize the chitin particles and decompose the chitin thanks to the concerted action of chitinases and deacetylases, otherwise they could not tolerate chitosan, a recognized antibacterial biopolymer. In fact, chitosan is used to prevent infections in fishes and crustaceans. Considering that chitin deacetylases play very important roles in the biological attack and defense systems, they may find applications for the biological control of fungal plant pathogens or insect pests in agriculture and for the biocontrol of opportunistic fungal human pathogens.  相似文献   

15.
中国水稻抗虫性的研究及其应用:回顾与展望   总被引:3,自引:2,他引:3  
简要地回顾了近30年来我国水稻抗虫性,特别是抗稻飞虱研究及其应用的历史,并将它划分为4个发展时期水稻抗虫种质资源发掘与评价期、水稻抗虫品种的外引和推广期、水稻品种抗虫机理和抗性生态研究期,以及水稻抗虫分子生物学和抗虫基因工程研究时期.还讨论了水稻抗虫品种的研究与应用中仍然存在的难题和障碍,并展望其发展前景.  相似文献   

16.
This review highlights recombinant DNA technology as a powerful tool to enhance the gene pools of sorghum and pearl millet crops regarded as jewels of Africa. Although important advances in the improvement of these species have been made by classical breeding and modern marker assisted selection, genetic manipulation and in vitro culture allows the gene pool to be broadened beyond that normally available for improvement by allowing the transfer of genes which control well-defined traits between species. The current state of sorghum and millet transformation technology is summarised and applications in the improvement of nutritional quality and the resistance to pathogens and pests for crops grown in Africa and Asia is discussed. Regulatory aspects including gene flow and future prospects are also discussed.  相似文献   

17.
This review highlights recombinant DNA technology as a powerful tool to enhance the gene pools of sorghum and pearl millet crops regarded as jewels of Africa. Although important advances in the improvement of these species have been made by classical breeding and modern marker assisted selection, genetic manipulation and in vitro culture allows the gene pool to be broadened beyond that normally available for improvement by allowing the transfer of genes which control well-defined traits between species. The current state of sorghum and millet transformation technology is summarised and applications in the improvement of nutritional quality and the resistance to pathogens and pests for crops grown in Africa and Asia is discussed. Regulatory aspects including gene flow and future prospects are also discussed.  相似文献   

18.
To improve sorghum grain protein nutritional quality, improved sorghum lines were transformed to suppress the synthesis of different kafirin sub-classes, or backcrossed into transgenic lines with improved protein quality. Co-suppression of the alpha-, gamma- and delta-kafirin sub-classes and removal of the tannin trait resulted in transgenic sorghum lines with high cooked protein digestibility (±80%), improved Amino Acid Score (0.8) and Protein Digestibility Corrected Amino Acid Score (0.7) compared to the non-transgenic null controls (±50%, 0.4 and 0.2, respectively). These high protein quality lines had a floury endosperm. They also had modified protein body structure, where the protein bodies were irregular shaped with few to numerous invaginations and were less densely packed, with a dense protein matrix visible around the protein bodies. When fewer sub-classes were suppressed, i.e. gamma 1 and delta 2, the endosperm was corneous with normal protein body structure but the improvement in cooked protein digestibility appeared to be less. Apparently, co-suppression of several kafirin sub-classes is required to obtain high protein nutritional quality sorghum lines, but this seems to result in floury-type grain endosperm texture.  相似文献   

19.
江淮地区温光水资源丰富,是我国重要的粮食主产区之一。该地区地处南北气候过度地带,病虫草害类型复杂,病虫草害绿色防控是确保粮食安全生产的重要保障措施。江淮地区作物周年种植,模式多样,其中以稻-麦轮作种植模式为主。本研究根据安徽粮丰项目试验示范成果,结合江淮稻-麦周年生产实际,针对稻-麦周年生长不同生育期主要靶标病虫草害发生规律和为害特点,集成了以农业生态技术措施为前提、绿色防控投入品综合应用为基础、药械联用精准减量高效防控靶标生物技术为突破口的绿色防控技术模式,并成功示范推广。本文就该技术模式进行了详细介绍,以期为区域粮食绿色安全可持续生产提供技术支持。  相似文献   

20.
Uncooked and cooked sorghum showed improvement in in vitro protein digestibility as the structural complexity of the sample reduced from whole grain flour through endosperm flour to protein body-enriched samples. This was not the case for maize. Cooking reduced protein digestibility of sorghum but not maize. Treating cooked sorghum and maize whole grain and endosperm flours with alpha -amylase to reduce sample complexity before in vitro pepsin digestion slightly improved protein digestibility. The reduction in sorghum protein digestibility on cooking was not related to the total polyphenol content of samples. Pericarp components, germ, endosperm cell walls, and gelatinised starch were identified as possible factors limiting sorghum protein digestibility. Electrophoresis of uncooked and cooked protein-body-enriched samples of sorghum and maize, and prolamin fractions of sorghum under non-reducing conditions showed oligomeric proteins with molecular weights (Mr) 45, 66 and >66 kDa and monomeric kafirins and zeins. Protein-body-enriched samples of sorghum had more 45–50 kDa oligomers than those of maize. In cooked sorghum, some of these were resistant to reduction. Pepsin-indigestible residues from protein-body-enriched samples consisted mainly of α-zein (uncooked and cooked maize) or α-kafirin (uncooked sorghum), whilst cooked sorghum had in addition, β- and γ-kafirin and reduction-resistant 45–50 kDa oligomers. Cooking appears to lead to formation of disulphide-bonded oligomeric proteins that occurs to a greater extent in sorghum than in maize. This may explain the poorer protein digestibility of cooked sorghum.  相似文献   

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