Nutritive value of baobab milk (gubdi) and mixtures of baobab (Adansonia digitata L.) and hungry rice,acha (Digitaria exilis) flours

The baobab milk and fermented baobab/acha flour mixtures were analyzed chemically for their proximate, ascorbate, mineral and antinutrient composition. The dry pulp scraped from baobab fruits was kneaded, made into solution, extracted through cheese-cloth and stored frozen until analyzed. The acha and baobab grains were cleaned, fermented for 24 to 120 hours, dried and hammermilled into fine flours. The unfermented flours served as controls. The standard assay methods of AOAC were selected for use for the analysis of the nutrients and the antinutrients. The mixtures were composed of 70% acha and 30% baobab flours (70:30 protein basis). The baobab milk contained more protein (1.5%) and minerals (Fe, 17.8 mg; Ca 134.2 mg) than those of human milk (protein, 1.3%, Fe, 0.2 mg, Ca 30 mg) and cow milk (Fe, 0.1 mg; Ca 1.20 mg) and most leading national commercial infant formulas e.g. cerelac (Fe, 10.0 mg). The composite flours contained more nutrients than the baobab or the acha flour alone. The BF96 had greater advantage over other BF flours as a supplement to acha. The mixtures are within the reach of lower income group and can be incorporated into their diets.     

Antiradical properties of sorghum (Sorghum bicolor L. Moench) flour extracts

Epidemiological studies support the belief that whole grains are protective against several chronic diseases. The health benefits of whole grains are attributed in part to their unique phytochemical composition. Major phytochemicals in grains include various classes of phenolic compounds, flavonoids and coumarin derivatives, etc. Phenolic compounds present in grains possess antioxidant properties that are associated with the health benefits of grains and grain products. Sorghum is one of the main staple cereal grains in hot dry tropics and ranks fifth among cereal crops in the world. Although sorghum is rich in phenolics and tannins which are proven anticancer and cardioprotective constituents, human consumption of sorghum is limited. To our knowledge, there is limited literature on the profile of antioxidant phytochemicals in the local white variety of sorghum. Hence, the objective of this study was to investigate the antioxidant property of white sorghum flour extracts in vitro and also to identify the fractions responsible for the antioxidant activity. In the present study, we analyzed the antioxidative properties of various extracts (water, 60% methanol, 60% ethanol, and 60% t-butanol) of white sorghum flour employing the 1,1-diphenyl-2-picrylhydrazyl (DPPH) model system. Phenolics, antiradical and antioxidant activities were also examined in chromatographic sub-fractions of the soxhlet methanolic extract. Our results indicated that the various extracts exhibited significant antioxidant activity that did not correlate with the phenolic content. Further, two sub-fractions eluted with methanol and acetone/methanol were found to possess strong antioxidant activity in two assay systems. Our results suggest that a diet rich in sorghum may be useful in combating diseases in which free radical production plays a key role.     

The nutritive value of amaranth grain (Amaranthus caudatus)

Digestibility of dietary fibre (DF) and energy of three pale-seeded and one darkseeded variety ofAmaranthus caudatus were studied in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 8% of DF and the black seeds about twice as much. The soluble DF fraction made up 33–44% of the total DF (TDF) fraction in the pale-seeded varieties, but only 18% in the black seeds. The monomer sugar composition of the DF was very similar in all products. However, the black seeds were very high in lignin, and DF of the black-seeded products were more resistant to digestion than that of the pale-coloured products. In the pale amaranth products digestible energy (DE) varied between 86 and 91%. In the dark-seeded products DE was lower, and there was a significant negative correlation (r=–0.92) between DE and TDF. Processing of pale seeds had only minor effects on TDF and DE, but increased the proportion of soluble DF and the digestibility of DF in one variety. The food intake tended to be lower in rats fed raw pale seeds compared with those consuming processed products, indicating the presence of heat-labile factors reducing palatability.In conclusion, the pale seeds had a lower content of DF than most cereal grains and the DF was more easily digested. As a source of energy, amaranth grains seem to be comparable to other cereals.     

Variation of Beta -Amylase Activity in Barley as Affected by Cultivar and Environment and its Relation to Protein Content and Grain Weight

The cultivar and environmental variation of beta -amylase activity was studied using two barley cultivars with contrasting growth properties. There was a significant difference in beta -amylase activity between the two cultivars used, 92-11 being significantly higher than Xiumai 3. A significant variation in beta -amylase activity was detected between grains at different positions within a spike. The two cultivars showed the same pattern, with top grains showing the highest and bottom ones the lowest activities. The relative difference within a spike varied between the cultivars, with 92-11 being larger than Xiumai 3. Both seeding rate and timing of N application dramatically affected the beta -amylase activity. With N application at the booting stage, beta -amylase activity increased, mainly due to the significantly increased beta-amylase activity in the topmost grains. The bottom grains showed a lower response to timing of N application. The variation in protein content and grain weight between cultivars and among the various treatments was also examined. The possible influence of these factors on beta -amylase activity are discussed.     

The nutritive value of amaranth grain (Amaranthus caudatus)

The nutritional value of three pale seeded and one dark seeded variety ofAmaranthus caudatus was studied by chemical analyses and in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 14% protein, 10% fat, 2.5% ash, 64% starch and 8% of dietary fibre. The black seeds had a much higher content of fibre (16%). The concentration of essential amino acids were high. Lysine ranged from 5.2–6.0 g/16 g N in the grains, and the limiting amino acids were leucine followed by valine or threonine. The grains contained small amounts of tannin (0.3%) and heat-labile protease inhibitor activity, at levels typical of common cereal grains. Digestibility of protein in the pale seeds was high (87%) and quite unaffected by processing. Protein digestibility of the black seeds was lower, and the digestibility was further reduced by toasting. The biological value of the protein was similar in all products, and very high. The content of minerals varied among varieties and was also affected by processing. Phytate: zinc molar ratios were high in most products, and rats fed the amaranth samples with the lowest zinc contents were in negative zinc balance. In general, femur zinc concentrations were rather low. However, amaranth is an unconventional crop which deserves further attention.     

Metabolite profile of whole grain ting (a Southern African fermented product) obtained using two strains of Lactobacillus fermentum

Ting is a traditional fermented sorghum product mostly eaten in Southern Africa, generally believed to be highly nutritious and rich in health beneficial properties. Although refined grains are mostly used for fermented foods, the use of whole grains (WGs) in fermented products is gradually gaining prominence due to their benefits. In this study, Lactobacillus fermentum strains were used singly and in combination for the fermentation of WG-ting from WG-sorghum and all possible metabolites profiled using gas chromatography-high resolution time of flight-mass spectrometry. 198 compounds were observed in the experimented samples, classified into different metabolic groups, with varying proportions: esters (23%), ketones (10%), fatty acids methyl esters (7%), and hydrocarbons (6%). Other important metabolites include vitamins, terpenes and terpenoids, phytosterols, phenols, and alcohols. Although similar lactic acid bacteria were used, differences were observed in levels of the metabolites and in some instances, the types of metabolites obtained differ. Much of the differences were attributed to varying fermentation behaviours of the strains, which could be related to their inherent genes. The correlation between metabolites from raw sorghum and the fermented product may assist in developing processing methods to retain the desired metabolites and enhance their functional potentials toward product improvement and for health benefits.     

Traditional production,consumption and storage of Kunu – a non alcoholic cereal beverage

A survey of the production, consumption and storage ofKunu was carried out. Some of the information included consumption rate, processing techniques andequipment, producer's status and grains used. About73% consume Kunu daily, 26% occasionally; 1% knowit is produced but may or may not be consuming it. Millet (Pennisetum typhoideum), sorghum (Sorghum vulgare), maize (Zea mays), rice (Oryza sativa) and acha (Digitalis exilis) wereused in its production in decreasing order ofpreference. The grains were used singly or combined;sorghum/millet was the most common combination in aratio of 1:2 (w/w). Steeping was done in ordinary water for 12–72 h, depending on the grain type, in localclay pots, plastic buckets, calabashes or basins or5–7 h in warm water (60–70 ^°C). The grainswere dry or wet milled with or without spices such asginger, red pepper, black pepper, clove and garlic.Other ingredients introduced included: sweet potatoes,malted rice, malted sorghum and Cadaba farinosacrude extract. Both dry and wet milling was done withgrinding mills, mill stones or mortar and pestle,depending on locality. The product was then cookedinto a thin free flowing gruel. The various types ofkunu were: Kunun zaki, Kunun gyada, Kunun akamu, Kununtsamiya, Kunun baule, Kunun jiko, Amshau and Kunungayamba. Kunun zaki was the most commonly consumed. Production and consumption cut across all socialclasses of the society.     

Minor components and wheat quality: Perspectives on climate changes

Minor compounds of cereal grains such as lipids and cell wall polysaccharides play an important role in their milling properties, their transformation into baked cereal products and their nutritional properties. These effects are mainly due to their interactive properties, such as their ability to absorb large amounts of water for polysaccharides or to interact with starch polymers and proteins for lipids. Environmental stress induced by climate change and regulations for environmentally friendly agriculture can interfere with the biosynthesis of these minor grain compounds as well as the main compounds starch and protein. Indeed, the metabolic networks of all components of the endosperm of grains are closely associated. Therefore, in the context of climate change and agricultural sustainability, lipids and cell wall polysaccharides may be affected. Contrasting with a plethora of studies reporting the impact of environment and fertilizer on cereal proteins, there is a real lack of information on this particular topic for these minor compounds. However, our knowledge of the physico-chemical properties and biosynthesis of these minor compounds allows us to assess the likely strong impact of environmental and agronomic constraints on the relationships between cell wall polysaccharides, lipids and cereal quality.     

Protein quality of some Nigerian traditional diets based on the African yambean (Sphenostylis stenocarpa) and pigeon pea (Cajanus cajan)

The protein quality of Nigerian traditional diets based on the African yambean (AYB) and pigeon pea (PP) were performed by in vivo and in vitro bioassays. The individual foods were processed, cooked, dried and mixed to resemble the traditional diets. Weanling male Wistar rats (45–55 g) were used for the bioassay. The rats were fed ad libitum for 35 days of which 28 days were for growth and 7 days for N-balance. All the eleven diets including casein (control) provided 1.6 g N/100 g diet. The parameters tested include PER, growth, N-balance, BV, NPU and apparent digestibility (AD). The rats fed the AYB diets, except AYB: Agidi (Ag), showed superiority in most of the parameters tested. There were significant positive correlations between PER and NPU (r=0.925;p<0.001); PER and AD (r=0.908;p<0.001); PER and body weight gain (r=0.969;p<0.001). The in vitro protein digestibility of the diets was significantly correlated (r=0.80;p<0.01) with the in vivo apparent digestibility. These parameters were used to rank the various diets. Crayfish protein was a better supplement to legume/cereal or legume starchy staple mixtures than leguminous oil seed. However, supplementation of PP: steamed corn (SC) diet with crayfish did not prove beneficial. The result showed that diets based on the African yambean, an under-exploited legume, are nutritious. The need for its reintroduction into the fare of the populace through increased production and appropriate processing technology is stressed. The results of this study can form a base for the standardization of Nigerian diets based on these legumes.     

Fusarium Species Synthesize Alkaline Proteinases in Infested Barley

Barley (Hordeum vulgare L.) that is infested with Fusarium head blight (FHB, ‘scab’) is unsuitable for malting and brewing because it may contain mycotoxins and has unacceptable malting quality. Fungal proteinases are apparently often involved in plant-microbe interactions, where they degrade storage proteins, but very little is known about the enzymes that the fungi produce in the infected grain. We have shown previously that one plant pathogenic fungus, Fusarium culmorum, produced subtilisin- and trypsin-like enzymes when grown in a cereal protein medium. To establish whether these proteinases were also synthesized in FHB-infested barley in vivo, field-grown barley was infested as the heads emerged. Extracts were prepared from the grain as it developed and matured and their proteolytic activities were measured with N-succinyl-Ala-Ala-Pro-Phe p -nitroanilide and N-benzoyl-Val-Gly-Arg p -nitroanilide. The heavily infested barleys contained both subtilisin- and trypsin-like activities. These enzymes reacted with antibodies prepared against each of the two F. culmorum proteinases, indicating that those produced in the laboratory cultures and in the field-infested barley were the same. The presence of these proteinases correlated with the degradation of specific buffer-soluble proteins in the infested grains. These enzymes readily hydrolyzed barley grain storage proteins (C- and D-hordeins) in vitro. The presence of these Fusarium proteinases in the barley indicates that they probably play an important role in the infestation, but exactly how and when they function is not clear.     

CerealBeta-Amylases

Cerealbeta-amylases are perhaps best known in terms of the vital role they play in releasing easily fermentable sugars from cereal grain starch to fuel the production of alcohol by yeast in brewing. The extent to which they have been investigated is indeed largely due to their significance in this economically important industry. However, cerealbeta-amylases are also, or could be, employed in many other aspects of the food industry and the analysis of starch, and they constitute valuable markers in cereal assessment and breeding studies. Quite apart from their practical significance, they are rewarding objects of biochemical and physiological research. They are interesting models for the study of enzyme polymorphism, post-translational modification and the differential expression of isoenzymes. In spite of their often high activitiesin situand all that is known about their generation, they are an enigma in that their physiological function, or even necessity, remains unclear. It has been recently recognised that there are two different categories of cerealbeta-amylases which exhibit different tissue and taxonomic specificities and physiological developmental patterns. The «classical»beta-amylases present at high activities in cereal seeds appear to be limited to the endosperm of the species of the Triticeae tribe of the Festucoideae subfamily of the Gramineae (wheat, barley and rye), whereas all cereals exhibit a different, tissue-«ubiquitous» form of the enzyme which is present at much lower activity levels. The physiological phenomenology and the usage of cerealbeta-amylases are discussed in relation to these two categories of enzyme.     

Carotenoid evolution during postharvest storage of durum wheat (Triticum turgidum conv. durum) and tritordeum (×Tritordeum Ascherson et Graebner) grains

The process of in vivo esterification of xanthophylls has proven to be an important part of the post-carotenogenesis metabolism which mediates their accumulation in plants. The biochemical characterization of this process is therefore necessary for obtaining new and improved crop varieties with higher carotenoid contents. This study investigates the impact of postharvest storage conditions on carotenoid composition, with special attention to the esterified pigments (monoesters, diesters and their regioisomers), in durum wheat and tritordeum, a novel cereal with remarkable carotenoid content. For tritordeum grains, the total carotenoid content decreased during the storage period in a clear temperature-dependent manner. On the contrary, carotenoid metabolism in durum wheat was very much dependent on the physiological adaptation of the grains to the imposed conditions. Interestingly, when thermal conditions were more intense (37 °C), a higher carotenoid retention was observed for tritordeum, and was directly related to the de novo esterification of the lutein induced by temperature. The profile of lutein monoester regioisomers was constant during storage, indicating that the regioisomeric selectivity of the XAT enzymes was not altered by temperature. These data can be useful for optimizing the storage conditions of grains favoring a greater contribution of carotenoids from these staple foods.     

Antioxidative and Antigenotoxic Activity of Extracts from Cosmos (Cosmos bipinnatus) Flowers

The Cosmos bipinnatus has been used in a traditional herbal remedy for various diseases such as jaundice, intermittent fever, and splenomegaly. The present study describes the preliminary evaluation of antioxidant activities and antigenotoxic effect of Cosmos bipinnatus flowers according to four different colors (white, pink, orange, and violet). The antioxidants properties were evaluated by determining TPC, DPPH RSA, ABTS RSA, and RP. The highest TPC of methanolic CFE (at concentration of 1 mg/ml) showed in violet colored CF (1,013 μM), and IC₅₀ of DPPH RSA, ABTS RSA, and RP were also the lowest in violet colored CFE with values of 0.61, 1.48, and 0.82 mg/ml, respectively. The antigenotoxic effect of the CFE on DNA damage induced by H₂O₂ in human leukocytes was evaluated by Comet assay. Pretreatments with CFE produced significant reductions in oxidative DNA damage at the concentration of 500 μg/ml, except for violet colored CFE. The ED₅₀ value of white colored CFE has shown the highest inhibition (0.40 mg/ml) on H₂O₂ induced DNA damage, followed by orange > pink > violet color. These results suggested that Cosmos bipinnatus has significant antioxidant activity and protective effect against oxidative DNA damage.     

Improving cereal grain carbohydrates for diet and health

Starch and cell wall polysaccharides (dietary fibre) of cereal grains contribute to the health benefits associated with the consumption of whole grain cereal products, including reduced risk of obesity, type 2 diabetes, cardiovascular disease and colorectal cancer. The physiological bases for these effects are reviewed in relation to the structures and physical properties of the polysaccharides and their behaviour (including digestion and fermentation) in the gastro-intestinal tract. Strategies for modifying the content and composition of grain polysaccharides to increase their health benefits are discussed, including exploiting natural variation and using mutagenesis and transgenesis to generate further variation. These studies will facilitate the development of new types of cereals and cereal products to face the major health challenges of the 21st century.     

Ae显性突变体对玉米农艺性状及直链淀粉含量的影响分析

玉米直链淀粉是重要的食品和工业原料,高直链淀粉性状的产生受多种酶和基因-环境等因素的共同影响。玉米ae基因（amylose extender）突变导致子粒中直链淀粉含量增高、子粒表面皱缩、淀粉颗粒呈不规则形状、尺寸不均匀且表面基质蛋白增多,用于玉米育种后获得的品种直链淀粉含量升高,产量显著降低。通过将显性Ae突变体与16份优质玉米自交系杂交,对F₁代植株进行开花期、株型、产量性状调查,分析F₁代子粒总淀粉、直链淀粉的含量。结果表明,Ae突变体与不同的自交系杂交,F₁代直链淀粉含量及产量的变化存在明显差异,与基因型有密切关系,以Ae突变体和W16F41、CA240为亲本杂交,可显著提高直链淀粉含量同时产量变化最小。根据F₁代表现筛选直链淀粉含量提高、产量变化较小的双亲配制杂交种,可加速高直链淀粉玉米新品种培育进程。     

Dual extraction of essential oil and podophyllotoxin from Juniperus virginiana

The leaves (needles) of eastern red cedar (Juniperus virginiana L.) contain two important natural products: essential oil and podophyllotoxin. The hypothesis of this study was that it may be possible to extract both essential oil and podophyllotoxin from the leaves of the tree, by using a dual extraction method. Podophyllotoxin was obtained from the leaves following steam distillation of the leaves to produce the essential oil, indicating that steam distillation did not degrade podophyllotoxin. Furthermore, a product with 6% purity podophyllotoxin was obtained from the steam-distilled plant material, demonstrating the possibility for the establishment of an industrially economic protocol for dual extraction of these two natural products. Our study demonstrated that J. virginiana leaves, currently a waste-product from the timber industry, could be sequentially extracted for essential oil and podophyllotoxin and utilized as a by-product instead. We also found that the J. virginiana heartwood (a traditional source for cedarwood essential oil) does not contain podophyllotoxin. This is the first study to report both podophyllotoxin and essential oil in J. virginiana, and the first report on the dual extraction of these two natural products from the same biomass samples.     

Barley for food: Characteristics,improvement, and renewed interest

Barley (Hordeum vulgare vulgare L.) is an ancient cereal grain, which upon domestication has evolved from largely a food grain to a feed and malting grain. However, barley food use today remains important in some cultures around the world, particularly in Asia and northern Africa, and there is renewed interest throughout the world in barley food because of its nutritional value. This review covers basic and general information on barley food use and barley grain processing for food use, as well as an in-depth look at several major aspects/traits of interest for barley food use including kernel hardness and colour, grain starch, and β-glucan contents. These traits are described in terms of their effects on processing and nutrition, as well as their inheritance and the prospects for barley improvement through breeding. Whereas, the aspects listed above have been studied relatively extensively in barley in terms of content, form, genetics, physiology, and in some cases nutritional quality, little is know about functional properties for processing and food product development. Renewed interest in barley for food uses largely centres around the effects of β-glucans on lowering blood cholesterol levels and glycemic index. Wholegrain barley foods also appear to be associated with increased satiety and weight loss. There is great potential to utilise barley in a large number of cereal-based food products as a substitute partially or wholly for currently used cereal grains such as wheat (Triticum aestivum), oat (Avena sativa), rice (Oryza sativa), and maize (Zea mays).     

Production of Proteases by Fusarium Species Grown on Barley Grains and in Media Containing Cereal Proteins

The production of proteases by the cereal plant pathogens Fusarium culmorum, F. graminearum and F. poae was followed through seven days of cultivation. The fungi were grown in mineral and in gluten culture media, and on autoclaved barley grains. The proteolytic activities of each sample were analysed at pH 2·2, 5·0 and 8·0 and the pH optima of the most active proteases were determined. All of the fungi grown in the gluten medium produced proteases that were active at pH levels between 6 and 10 and were most active at about pH 9·0. Fusarium poae also produced acid protease(s) with pH optima between 3.0 and 3.5 when grown in the gluten medium. No protease activity was detected in the cultures that were grown in the mineral medium, except that a small amount was formed after the glucose substrate was depleted. When grown on the barley grain medium the Fusarium species produced protease activities that were similar to the neutral and alkaline ones present in the gluten cultures, but no pH 2·2 protease activity was detected. The alkaline proteases had some characteristics that were similar to those of chymotrypsin.     

A real-time polymerase chain reaction (PCR) method for the identification of Nicotiana tabacum in tobacco products

A simple and specific real-time PCR assay based on TaqMan^® technology has been developed for the identification of cultured tobacco (Nicotiana tabacum) in various commodities such as cigars, cigarettes and reconstituted tobacco. The TaqMan^® assay targets a sequence of the putrescine N-methyltransferase gene family encoding an enzyme that plays a crucial role in the biosynthesis of nicotine. To reduce the possibility of false negatives, universal plant chloroplast primers were also used in a separate real-time PCR reaction to give indication if DNA is amplifiable in the matrix. The TaqMan^® assay successfully identified tobacco in over 40 commercial tobacco products, while negative results were obtained from the assay for DNA extracted from a variety of other botanical products. In our study, two commercial DNA isolation kits were used, namely, the Qiagen DNeasy^® Plant Mini kit and the Qiagen Gentra^® Puregene^® kit. They produced good quality DNAs in sufficient quantities for real-time PCR analysis. In a few cases, an additional purification step with the Promega DNA IQ™ system had to be implemented to obtain amplifiable DNA.     

大麦转基因技术研究进展及其应用

大麦是世界第四大禾谷类作物,种植范围和用途极为广泛。近十年来,大麦转基因研究取得了很大进展。本文概述了大麦遗传转化的主要方法,着重介绍农杆菌介导法转化大麦的研究成果,分析影响其转化效率的因素;总结了转基因技术在大麦遗传研究中的应用,包括生物和非生物胁迫抗/耐性、籽粒产量、麦芽和营养品质改良,以及饲用酶和其他重组蛋白的生产等。