In vitro digestibility of processed and fermented soya bean,cowpea and maize

Tropical legumes, ie soya bean and cowpea, were pre‐treated and subsequently fermented using pure cultures of Rhizopus spp. Impact of soaking, cooking and fermentation of the legumes on their digestibility was determined using an in vitro digestion method. Processing of white maize included, amongst others, natural lactic acid fermentation, cooking and saccharification using barley malt. An in vitro method was standardised to carry out comparative determinations of the dry matter digestibility of cereal and legume food samples as a function of processing conditions, without attempting to exactly mimic gastrointestinal digestion. Using this method based on upper digestive tract digestion, it was observed that digestibility of the legumes increased during cooking and fermentation. Cooking improved the total digestibility of both soya bean and cowpea from 36.5 to 44.8% and from 15.4 to 40.9% respectively. Subsequent fungal fermentation increased total digestibility only by about 3% for both soya bean and cowpea. Digestibility was also influenced by fungal strain and fermentation time. Cooking and subsequent saccharification using malt almost tripled total digestibility of white maize from 25.5 to 63.6%, whereas lactic fermentation of maize had no effect on in vitro dry matter digestibility. Although total digestibility of cooked legumes was only slightly improved by mould fermentation (3% for both soya bean and cowpea), the level of water‐soluble dry matter of food samples increased during fermentation with Rhizopus oryzae from 7.0 up to 27.3% for soya bean and from 4.3 up to 24.1% for cowpea. These fermented products could therefore play a role as sources of easily available nutrients for individuals suffering from digestive disorders. © 2000 Society of Chemical Industry     

Chemical,rheological and sensory characteristics of sweet spreads made from by-products of soya bean and maize

Sweet maize cob (SMC) and black soya bean seed coat (BSC) were used to prepare a sweet spread. Chemical composition of the prepared spread and its rheological and sensory characteristics were investigated. The results were compared with those of commercial plum and raspberry jams and spreads. Spreads made from SMC and BSC had the highest content of proteins, total fibres, hemicellulose and cellulose. In relation to fruit jams, they are distinguished by the presence and content of p-coumaric, ferulic and 3,4-dihydroxybenzoic acids, as well as of flavonoids such as catechin and quercetin. SMC spread with 3.2% of BSC had the highest content of total anthocyanins (666.75 mg CGE kg⁻¹) (cyanidin 3-glucoside equivalent). Cyanidin-3-glucoside (Cy-3-Glu) was the most abundant anthocyanins in SMC/BSC containing spreads, while in raspberry jam, that was cyanidin-3-sophoroside (Cy-3-Sop). According to chemical, rheological and sensory properties, SMC/BSC containing spreads could be competitive with fruit jams and spreads.     

镉对玉米的毒害机理及积累和转运机制

由于工矿业的不合理发展,玉米(Zea mays L.)农业生产受到了土壤镉(Cd)污染的威胁。由于在Cd胁迫下玉米产量与品质降低,故外源Cd对玉米的毒害作用及其机理受到广泛关注。同时,玉米对Cd的吸收与积累导致Cd可能通过玉米产品进入食物链,威胁人类健康,因此对玉米Cd转运和积累机制的研究已经成为分子生物学与植物生理学研究的热点之一。文章通过介绍Cd胁迫对玉米内源性植物激素系统、光合作用、水分及矿质元素吸收的影响,分析Cd毒害机理,探讨了Cd在玉米中短距离运输和长距离运输的途径及镉移动过程中的积累机制,并提出了降低玉米Cd积累的农艺防控措施,以期为后续的研究提供新的思路与方向。     

Role of mineral nutrition in minimizing cadmium accumulation by plants

Cadmium (Cd) is a highly toxic heavy metal for both plants and animals. The presence of Cd in agricultural soils is of great concern regarding its entry into the food chain. Cadmium enters into the soil–plant environment mainly through anthropogenic activities. Compounds of Cd are more soluble than other heavy metals, so it is more available and readily taken up by plants and accumulates in different edible plant parts through which it enters the food chain. A number of approaches are being used to minimize the entry of Cd into the food chain. Proper plant nutrition is one of the good strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain. Plant nutrients play a very important role in developing plant tolerance to Cd toxicity and thus, low Cd accumulation in different plant parts. In this report, the role of some macronutrients (nitrogen, phosphorus, sulfur and calcium), micronutrients (zinc, iron and manganese), and silicon (a beneficial nutrient) has been discussed in detail as to how these nutrients play their role in decreasing Cd uptake and accumulation in crop plants. Copyright © 2010 Society of Chemical Industry     

Occurrence of mycotoxins in maize,grass and wheat silage for dairy cattle in the Netherlands

The occurrence of mycotoxins in 140 maize silages, 120 grass silages and 30 wheat silages produced in the Netherlands between 2002 and 2004 was determined using a liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) multi-method. Deoxynivalenol (DON) was detected above the limit of quantification (LOQ) of 250 μg kg^?1 in 72% of maize and 10% of wheat silages. Average DON concentrations were 854 and 621 μg kg^?1, respectively, and maximum concentrations 3142 and 1165 μg kg^?1, respectively. Zearalenone was detected above the LOQ of 25 μg kg^?1 in 49% of maize and 6% of grass silages. Average zearalenone concentrations were 174 and 93 μg kg^?1, respectively, and maximum concentrations 943 and 308 μg kg^?1, respectively. The incidences and average concentrations of DON and zearalenone in maize silage were highest in 2004. The incidence of other mycotoxins was low: fumonisin B1 and 15-acetyl-DON were detected in 1.4 and 5% of maize silages, respectively, and roquefortin C in 0.8% of grass silages. None of the silages contained aflatoxins, ochratoxin A, T2-toxin, HT2-toxin, sterigmatocystin, diacetoxyscirpenol, fusarenon-X, ergotamine, penicillinic acid, or mycophenolic acid. This study demonstrates that maize silage is an important source of DON and zearalenone in the diet of dairy cattle. Since the carryover of these mycotoxins into milk is negligible, their occurrence in feed is not considered to be of significant concern with respect to the safety of dairy products for consumers. Potential implications for animal health are discussed.     

Use of wheat,triticale and rye flours in layer cake production

In this study, the capacity of obtaining high quality layer cakes from rye and triticale lines was analysed and compared to wheat lines. The samples were characterised considering grain hardness, flour composition and quality parameters as protein, pentosan, damaged starch, pasting viscosity and functional predictive test – solvent retention capacity test. Cakes were analysed in weight, symmetry, volume, volume index (VI) by measuring the height in different points of the cake, crust and crumb colour, crumb structure and texture. Wheat and triticale cakes showed similar characteristics. Rye cakes showed higher volume and lower weight than those with crumbs darker in colour, higher adhesiveness, springiness and resilience. The multiple regression analysis was used to develop an equation for cake volume index prediction. The best‐fit linear regression model was: VI = 14.75 – 0.14 × protein + 0.93 × water soluble pentosan – 0.27 × total pentosan. Despite the differences, high quality cakes can be elaborated with rye, triticale and soft wheat cultivars.     

Aflatoxin production in three selected samples of triticale,wheat and rye grown in Argentina

Little is known about mycotoxin contamination of triticale, a hybrid resulting from crossing wheat and rye. The purpose of the present work was to evaluate triticale as a substrate for aflatoxin accumulation in comparison with its parents. Aflatoxin (B₁, B₂, G₁ and G₂) accumulation curves were obtained for the three substrates inoculated with Aspergillus parasiticus NRRL 2999 and incubated at 25 °C and water activity 0.925 for 10 weeks. Wheat and triticale were poor substrates for aflatoxin production. Rye was more prone than the other substrates to fast colonisation by A parasiticus and accumulated larger aflatoxin quantities over the whole incubation period. The maximum aflatoxin concentration in rye (11 840 µg kg⁻¹) was significantly larger (p < 0.05) than those obtained in wheat (2150 µg kg⁻¹) and triticale (2850 µg kg⁻¹). © 2000 Society of Chemical Industry     

Oxalate accumulation in napier grass and pearl millet × napier grass interspecific hybrids in relation to nitrogen nutrition,irrigation and temperature

The oxalate content of napier grass and of pearl millet × napier grass interspecific hybrids was studied in plants grown in midsummer in the field and in a phytotron under three temperature regimes. The plants in the field were irrigated every 3, 7 or 14 days and given at each irrigation a heavy application of nitrogen, not less than 5 kg N ha^?1 day^?1. The plants in the phytotron were irrigated daily with a complete nutrient solution containing 200 mg l^?1 of nitrogen. The highest total and soluble oxalate contents in the dry matter of field grown plants were 2·6 % and 1·3%, respectively. The oxalate status of the plant was not affected by the irrigation or N fertilisation. In contrast, plants grown in the phytotron accumulated as much as 4·4 % of total and 3·4% of soluble oxalates, and both decreased with advancing maturity irrespective of the temperature regime. The content of sodium + potassium in the dry matter was linearly correlated with oxalate content (r² = 0·78) in the pooled data of all four experiments reported herein. There was no change in oxalate with N content above 2·0 % of the dry matter. Below that level oxalate increased Steeply with N content. However, in this range, N content is linearly correlated with (Na + K) content, and so its relation with oxalate is indirect. Oxalate levels in the leaves were higher than in the stems and decreased in both plant parts with advancing maturity. Only small differences in oxalates were found between the hybrids tested. Napier grass accumulated more oxalate in the stem than its F₁ hybrid, both having higher concentrations in tounger stem internodes. NO differences in ozalate levels were found between the leaves of he parent grass and its hybrid It is concluded that a hazardous concentration of oxalate in millet × napier hybrids is unlikely even under intensive N fertilisation. Consequently, consideration of oxalate accumulation need not be a constraint in breeding for imporved hybrids of this grass.     

Microbiological profile of maize and rye flours, and sourdough used for the manufacture of traditional Portuguese bread

A thorough microbiological study of maize and rye flours, and sourdoughs obtained therefrom for eventual manufacture of broa – a dark sour bread typical in Northern Portugal, following artisanal practices, was carried out. Towards this purpose, samples were supplied by 14 artisanal producers, selected from 4 sub-regions, during two periods of the year. Total viable counts, as well as viable mesophilic and thermophilic microorganisms, yeasts and molds, Gram⁻ rods, endospore-forming and nonsporing Gram⁺ rods, and catalase⁺ and catalase⁻ Gram⁺ cocci were assayed for. The comprehensive experimental dataset unfolded a unique and rather complex wild microflora in flours and sourdoughs throughout the whole region, which did not discriminate among sub-regions or seasons, or flour source for that matter. However, fermentation played a major role upon the numbers of the various microbial groups: the viable counts of yeasts, lactobacilli, streptococci, lactococci, enterococci and leuconostocs increased, whereas those of molds, Enterobacteriaceae, Pseudomonadaceae, staphylococci and micrococci decreased.     

Variations in cadmium accumulation among rice cultivars and types and the selection of cultivars for reducing cadmium in the diet

A pot trial was conducted with 52 rice cultivars of different types collected from different origins. The results showed that there were great differences in Cd concentrations in straw, brown rice and grain chaff among the rice cultivars grown in a soil containing a Cd concentration of 100 mg kg^?1; the Cd concentrations in brown rice ranged from 0.22 to 2.86 mg kg^?1. The great genotypic differences in Cd concentrations indicated that it is possible to lower the Cd content of rice through cultivar selection and breeding. Significant differences were found in the Cd concentrations of the rice types of Indica consanguinity and those of Japonica consanguinity, but not between their origins. There were significant correlations between straw and brown rice in Cd concentration and in the total amount of Cd accumulated. The distribution ratios of the Cd accumulated in brown rice to the total Cd accumulation in the above‐ground rice plant varied greatly from 12.9 to 137.8 g kg^?1, and there was significant correlation between the distribution ratios and Cd concentrations in brown rice. These indicated that Cd concentration in rice grain is governed by the transport of Cd from root to shoot and also from shoot to grain. Cd concentrations in brown rice also correlated significantly with some important agronomic traits, as well as with nitrogen concentrations, one of the most important criteria for rice quality. Copyright © 2004 Society of Chemical Industry     

Use and impact of usual intake models on dietary exposure estimate and risk assessment of chemical substances: a practical example for cadmium,acrylamide and sulphites

To estimate of food and nutrient intakes, 24-h recalls are frequently used in dietary assessment. However intake data collected for a short period are a limited estimator of long-term usual intake. An important limitation of such data is that the within-person variability tends to inflate the intake distribution leading to a biased estimation of extreme percentiles. Statistical models, named usual-intake models, that separate the within-person variability from the between-persons variability, have lately been implemented. The main objectives of this study were to highlight the potential impact that usual-intake models can have on exposure estimate and risk assessment and to point out which are the key aspects to be considered in order to run these models properly and be sure to interpret the output correctly. To achieve the goal we used the consumption data obtained by the French dietary survey INCA2 and the concentration data collected during the French TDS2, using Monte Carlo Risk Assessment (MCRA) software, release 8.0. For the three substances included in this study (cadmium, acrylamide and sulphites), the exposure of the upper percentiles was significantly reduced when using usual-intake models in comparison with the results obtained in the observed individual mean models, even if in terms of risk assessment the impact of using usual-intake models was limited. From the results it appears that the key aspects to consider when using usual-intake models are: (1) the normality of the log-transformed intake distribution, (2) the contribution per single food group to the total exposure, and (3) the independency of food consumption data on multiple days. In conclusion, usual-intake models may have an impact on exposure estimates although, referring to the results, it did not bring any changes in terms of risk assessment, but further investigations are needed.     

常规PCR法同时检测食品中的小麦、大麦和黑麦致敏原

目的建立一种常规PCR法同时检测食品中的小麦、大麦和黑麦致敏原(WBR155bp)。方法采用ClustalW软件分析小麦ω-醇溶谷蛋白、大麦醇溶谷蛋白和黑麦ω-黑麦碱的核苷酸编码序列的同源性,进而确定同源区域,用Primer Premier5.0基于同源区域设计引物。选取不同种属的植物考查所建立PCR方法的特异性。将小麦粉,大麦粉、黑麦粉与米粉混合制备谷物含量梯度为100%、10%、1.0%、0.1%、0.01%的样品,考查WBR155 bp的检出限。结果扩增产物片段200 bp,可以检测到高度降解的DNA片段。引物WBR155bp对小麦、大麦和黑麦的检出限分别为1.0%, 0.01%和0.1%。结论该方法具有良好特异性,可用于食品中的小麦、大麦和黑麦致敏原的日常检测。     

Biochemical,textural and microstructural changes in whole‐soya bean cotyledon sufu during fermentation

This study aims to investigate the nutritional value of sufu and reduce environmental problems caused by okara, which results from the traditional processing method of sufu. The feasibility of the whole‐soya bean cotyledon sufu (WSCS) processing method, which does not produce okara, was investigated. WSCS was prepared by ripening okara‐containing tofu through various hydrolytic enzymes secreted by Actinomucor elegans for 70 days. After fermentation, total nitrogen, amino nitrogen and lipid contents were found to be lower in WSCS than in traditional sufu (TS), whereas contents of reducing sugar, dietary fibre, isoflavone aglycone and soya bean polysaccharide were higher in WSCS than in TS. The hardness, springiness and adhesiveness of WSCS were 249.703 ± 0.500 g, 0.606 ± 0.008 and 8.393 ± 0.032 J, respectively. The corresponding values for TS were 264.863 ± 0.572 g, 0.615 ± 0.007 and 7.516 ± 0.031 J, respectively. In addition, microstructural changes in WSCS and TS during fermentation were observed through scanning electron microscopy. The results from this study may provide a basis for industrial production of WSCS.     

Traffic-induced compaction in maize,cowpea and soya bean production on a tropical alfisol after ploughing and no-tillage: Crop growth

An experiment was conducted over three consecutive seasons during 1982 and 1983 to evaluate the effects of traffic-induced compaction on growth and yield of maize, cowpea and soya bean grown in a tropical Alfisol for no-tillage and ploughed systems. Compaction treatments of no, two and four passes of a 2-tonne roller were used on the sub-plots. The roller was 60 cm in diameter, 180 cm long, with a contact area of 0.1729 m² and was pulled by a 33.6 kW tractor. The four-pass treatment reduced percentage emergence, plant height, leaf number, leaf area index, and dry matter yield of maize, cowpea and soya bean. These reductions were more marked on ploughed than on no-till plots. The two-and four-pass treatments significantly reduced root growth of maize, cowpea and soya bean in the 0–70 mm depth, but the reduction in root density was greater in ploughed than in no-tillage. The two-and four-pass compaction treatments reduced plant nutrient uptake and grain yield of maize, cowpea and soya bean. The four-pass treatment reduced maize grain yield by 48% in all seasons under no-tillage and by 53, 61 and 75% after ploughing in the first, second and third consecutive cropping seasons respectively, compared to the yield of the relevant non-compacted treatment. Cowpea yield was reduced by 38% in all seasons after no-tillage and by 39, 50 and 57% after ploughing during the first, second and third consecutive cropping season respectively. The response of soya bean to four-pass compaction resulted in yield reduction by 50,64 and 25% after no-tillage and by 47, 48 and 65% after ploughing in the first, second and third consecutive cropping season, respectively. Crop yields were found to be negatively correlated with soil bulk density, penetrometer resistance, and relative compaction, and positively correlated with infiltration rate, soil moisture content and specific volume. Multiple regression equations were also developed between crop yield and soil properties.     

Use of grape by‐product as a source of dietary fibre and phenolic compounds in sourdough mixed rye bread

The study evaluated the effect of grape by‐products (GP) on the chemical composition, soluble (SDF) and insoluble (IDF) dietary fibre, phenolic compounds and antioxidant activity (AA) and organoleptic characteristics of sourdough mixed rye bread. The following samples of sourdough mixed rye bread were prepared: control bread (BC) and breads with GP at four different levels: 4%, 6%, 8% and 10%. Addition of GP significantly improves dietary fraction contents, as bread with a 10% addition of GP accounts for 39% and 37% higher contents of IDF and SDF than BC. The assay of radical‐scavenging activity and reducing ability showed that GP addition greatly enhanced antioxidant properties of mixed rye breads. Profiles of phenolic compounds of supplemented breads were dominated by procyanidin B1 and B2, catechin, epicatechin, caffeic acid and myricetin. With an increase in the level of GP, the hardness and gumminess of the bread significantly increase. Although both BC and supplemented breads showed common volatile compound profiles, there were slight differences in the concentrations of those components. Sensory evaluation of GP‐enhanced breads revealed that a maximum of 6% GP could be incorporated to prepare acceptable products.     

Traffic-induced compaction in maize,cowpea and soya bean production on a tropical alfisol after ploughing and no-tillage: Soil physical properties

An experiment was conducted over three consecutive seasons during 1982 and 1983 with the objective of evaluating the effects of traffic-induced compaction on soil physical properties of an Alfisol for no-till and ploughed systems. Main treatments of the split plot design consisted of disc ploughing to a depth of 200 mm followed by harrowing compared with no-seedbed preparation. Compaction treatments of none, two and four passes of a 2-tonne roller were the sub-plots. The roller was 60 cm in diameter, 180 cm long, with a contact area of 0.1729 m² and was pulled by a 33.6 kW tractor. Compaction treatments were applied 2 to 3 days before seeding. Four passes increased the penetrometer resistance of the soil surface, and bulk density; and as a result there were significant reductions in total porosity, saturated hydralic conductivity, infiltration rate and the amount of water released between 0.1 and 100 kPa suctions. Two passes of the roller had small and non-significant effects on soil properties. The effects of vehicular traffic in terms of increasing soil compaction became progressively severe with repeated compaction in subsequent seasons. Compaction affected soil properties in the 0–100 mm depth layer only, and was more evident following ploughing than following no-tillage systems.     

Enzyme activities,dietary fibre components and rheological properties of wholemeal flours from rye cultivars grown in Finland

Total and soluble dietary fibre, total and soluble pentosan and β‐glucan contents, activities of α‐amylase (EC 3.2.1.1) and endo‐β‐xylanase (EC 3.2.1.8) and viscous properties of aqueous suspensions of wholemeal flours during heating were determined in nine winter rye cultivars (Secale cereale L) grown in Finland in 1998–2001. There was marked annual and varietal differences in grain quality. In the rainy summer 1998 the yield was low, grains were small and dietary fibre content of the grains was high. Xylanase activity of the grains was high, which corresponded to the high content of soluble pentosans. In the dry summer of 1999, the pentosan content of the grains was low and β‐glucan content high. The effect of weather conditions and cultivar were also apparent in the differences in falling numbers, amylogram and swelling curve results. The two hybrid rye cultivars Esprit and Picasso had consistently highest falling numbers and amylogram peak viscosities. The activities of α‐amylase and xylanase had a moderate positive correlation with total pentosan content and the content of soluble pentosan. Xylanase activity had better correlation with the viscous properties of flour–water suspensions than α‐amylase. Surprisingly, α‐amylase activity had only a moderate negative correlation with falling number. Copyright © 2005 Society of Chemical Industry     

Genetic variation in the extract viscosity of rye (Secale cereale L.) bread made from endosperm and wholemeal flour: impact of high-molecular-weight arabinoxylan, starch and protein

BACKGROUND: To verify the viscous potential of rye bread made from population and hybrid cultivars, the overall extract viscosities (EVs) of endosperm and wholemeal breads (EBs and WMBs respectively) were assessed using extractants of different pH. Also, arabinoxylan‐dependent EV (AX‐EV) was determined after combined action of starch‐ and protein‐degrading enzymes. RESULTS: The synergistic effect of a combination of α‐amylase, amyloglucosidase and protease on EV was almost two times higher than the effects observed after single addition of each of them. However, water‐extractable arabinoxylans (WE AXs) were the major contributors to EV. Unexpectedly, a decrease in the mean WE AX contents observed in the following order, WMB (31.7 g kg^?1) and EB (29.3 g kg^?1) of hybrid rye and WMB (28.8 g kg^?1) and EB (23.8 g kg^?1) of population rye, was accompanied by an increase in their AX‐EVs (12, 21, 21 and 29 mPa s respectively). CONCLUSION: In some cases the structure of WE AXs is a more important determinant of AX‐EV than their content in rye bread. Nevertheless, both factors influence AX‐EV, which may reflect the viscosity of the human small intestine after rye bread consumption, related to some beneficial metabolic effects. Therefore AX‐EV can be a preliminary parameter for selection towards high‐viscosity bread. Copyright © 2010 Society of Chemical Industry