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1.
Wholegrain cereals are good sources of folate. However, little is known about folate in barley. In this study, total folate was analysed in five hulled Finnish barley cultivars from three harvesting years (2006–2008). In addition, different fractions were produced from two hulled cultivars by scarification and from mixes of hulled cultivars by industrial milling. Total folate was determined in all samples with a microbiological method and vitamer distribution in scarification and industrial milling fractions, using HPLC or UPLC. Limited variation was observed in the total folate content of the five cultivars. The average contents of the three harvest years ranged from 563 to 773 ng/g dm. Fractions containing germ and outer layers were the richest in folate. The highest total folate content in the scarification fractions was up to 1710 ng/g dm. The total folate content of the hull fraction obtained by dehulling 10% of the grains with an industrial pearler was almost 4-fold compared to the corresponding dehulled grain. This hull fraction is normally not used as food. The main folate vitamers in the fractions were 5-HCO-H4folate, 5-CH3-H4folate, 5,10-CH+-H4folate, and 10-HCO-PGA. Folate content could be enhanced naturally by introducing folate-rich fractions of barley into cereal products.  相似文献   

2.
There were substantial losses in thiamine, riboflavin and niacin contents of wheat, maize and sorghum grains at three infestation levels (25, 50 and 75%) caused by releasing two insect species viz.,Trogoderma granarium andRhizopertha dominica separately and mixed population. Losses were to the extent of 65 to 69% (thiamine), 50 to 67% (riboflavin) and 10 to 32% (niacin) due toT. granarium and 23 to 29% (thiamine), 13 to 18% (riboflavin) and 4 to 14% (niacin) due toR. dominica at 75% level of infestation in three cereal grains. Storage of grains (1–4 months) in insect free conditions did not show appreciable changes in the vitamin contents.  相似文献   

3.
Brown and milled rices were prepared from rough rice, and the nutritive value of the rices was studied by chemical analyses and in balance experiments with growing rats. The concentration of essential nutrients decreased with the degree of milling, but the energy density of brown and milled rices was similar. In the highly refined white rice the protein content was reduced to 86% and the mineral content to 23% of corresponding levels in brown rice. The zinc concentration was halved. The amino acid composition was rather unaffected by the degree of milling, but the lysine concentration was slightly lower in white rice than in brown rice. Milling was accompanied by an increase in true protein digestibility and a corresponding decrease in biological value. Thus net protein utilization of the different rices was remarkably uniform. A total of 33% of the utilizable protein and 22% of the digestible energy in brown rice was removed during milling. Rats fed rough, brown and lightly milled rices were unable to maintain their femur zinc concentration; deposition of calcium and phosphorus also appeared to be affected. Factors present in the outer part of the rice kernel interfere strongly with zinc utilization. Phytate and/or fibre are not solely responsible for this effect. Unless rice was milled into highly refined white rice, zinc status of rats was adversely affected. The results suggest that zinc might be a limiting factor in rice-based diets.  相似文献   

4.
The tryptophan contents of wheat, maize and barley grains were evaluated for samples originating from commercial and experimental cultivars, using a procedure that allowed the true quantity of this amino acid to be determined. For every cereal, a linear relationship was found between the level of tryptophan and the nitrogen (N) content of the grain. The results showed that previous reports of similar relationships underestimated tryptophan by 10 ± 5%, owing to tryptophan degradation during alkaline hydrolysis prior to analysis. Linear relationships between tryptophan and N have a low predictive value, however, since a high variability was observed in tryptophan content for any given grain nitrogen content.  相似文献   

5.
Rice fortification by parboiling has been used to fortify rice with a single or a combination of multiple nutrients. While several studies have demonstrated the success of rice fortification with minerals by the parboiling technique, the number of studies that used vitamins as fortificants is limited with varying results. A limited-water soaking method has been introduced as a feasible and more sustainable alternative to the conventional excess-water soaking in parboiling. This study investigated the application of limited-water soaking in the simultaneous fortification of rice with water- and fat-soluble vitamins. Pure and water-soluble forms of β-carotene and vitamin A were first compared to identify a more effective form to be combined with folic acid. Water-soluble forms of β-carotene and vitamin A were easy to incorporate into the soaking water and presented effective fortification without affecting rice milling quality, the amount of wastewater and solids in wastewater. Milled rice fortified with folic acid combined with water-soluble forms of β-carotene or vitamin A in the limited-water soaking method contributed to about 75% of the recommended dietary allowances (RDAs) for folic acid, about 173% (female) and 134% (male) of the RDAs for β-carotene, and to about 58% (female) and 45% (male) of the RDAs for vitamin A. Rice fortified with β-carotene showed a greater uptake and a more orange color compared to the others. Thus, fortification of rice with vitamins by limited-water parboiling is an efficient process to obtain fortified rice that can significantly increase vitamin intake with limited environmental impacts.  相似文献   

6.
This study was conducted to assess the food consumption pattern and nutrient intakes of pregnant women residing in Maku-the west north of Iran. In this cross-sectional study, 284 pregnant women (142 from urban area and 142 from rural areas) participated. Subjects were interviewed privately, face-to-face. Dietary intake data was collected using two 24 h recalls and a food frequency questionnaire for 3 months. Mean consumption of grains and dairies was higher in rural women compared to their counterparts in urban areas. Women in urban areas consumed 140 g fruits compared to 248 g consumed by rural women. There were no significant differences regarding consumption of vegetables, pulses, fat and oils between these two groups. All women consumed adequate amount of energy, protein, thiamin and niacin (> 75% RDA). Intake of vitamin B6, folate, vitamins A and D, iron, phosphorus, calcium, magnesium and zinc was not sufficient in these women. Inadequate intake of vitamin C and riboflavin was also reported in urban women. Percentage of energy from carbohydrate, fat and protein was 66, 23 and 11% for urban women, respectively and 68, 20 and 12% for rural women, respectively. Iron intake was lower in urban women compared to rural women. The findings indicated that rural women have better nutritional status than urban women. Future studies should determine factors associated with food consumption pattern in these women.  相似文献   

7.
To select elite germplasms, 112 mutants derived from japonica rice cultivar Wuyujing 3 were evaluated. The yield components such as panicle number per square meter, grain number per panicle, and grain weight were measured. The quality traits such as percentage of chalky grains(PCG), brown rice yield(BRY), milled rice yield(MRY), degree of milling(DM), amylose content(AC), protein content(PC), and relationships among traits were inverstigated. Results showed that grain yield ranged from 2.15 to 12.49 t/hm~2 with a mean of 6.4 t/hm~2 and number of grains per square meter contributed for 94.64% in grain yield variation. For quality traits, all rice mutants had short size(grain length ≤ 5.5 mm) and bold shape(grain length to width ratio = 1.10–2.00). Most of rice mutants(87.5%) had PCG values below 20%. All mutants had MRY values above 50%, AC values below 20%, and PC values below 10%. Percentage of chalky grains was significantly negatively correlated with MRY and positively correlated with DM. BRY and MRY were significantly negatively correlated with DM. PC was significantly and positively correlated with MRY and negatively correlated with DM, while AC had no significant correlation with these quality traits. It was concluded that there were 25 rice mutants which fulfilled the major requirements of Jiangsu standard japonica rice such as low percentage of chalky grains, low amylose content, optimal protein content, and which could be used as elite germplasms. Thus the mutants identified may lead to significant progress in improvement of rice quality.  相似文献   

8.
Extrusion is a multi-step thermal process which has been extensively utilized in food preparations. Effects of temperature, moisture content and speed screw on the stabilization of rice bran were optimized using response surface methodology. Furthermore, the effect of extrusion processing on the physicochemical, nutritional and functional properties of Tarom and Domesiah cultivars stabilized rice bran (SRB) were studied. The colour of rice bran was improved by extrusion processing, but the protein content was reduced, which can be related to the denaturation of protein. Extrusion had also a reduction significant effect on the phyitic acid and vitamin E in stabilized rice bran. However, the content of vitamins B2, B3, B5 and folic acid were remained unchanged, but the dietary fibre was enhanced which has beneficial health effect. In comparison with raw rice bran, water holding capacity was enhanced, but the oil absorption capacity was reduced. Foaming capacity and foaming stability of SRB was more than that of untreated rice bran. Although, they were less than that of rice bran protein concentrate/isolate. As a result, extrusion process improves some functional and nutritional properties of rice bran which are valuable for industrial applications and have potential as food ingredient to improve consumer health.  相似文献   

9.
There have been no studies conducted with the objective of investigating the effect of elevated CO2 concentrations ([CO2]) on antioxidants in grains. Therefore, a two-year field experiment was conducted using open-top chambers with two levels of atmospheric CO2 (375 and 550 μmol/mol) to evaluate their effects on rice grain antioxidants. Following exposure to high [CO2], the total phenolic content of all rice milling fractions decreased (3%–18%), with the highest reduction in the brown rice for sinapic acid (167%), and in the white rice for p-hydroxybenzoic acid (100%). The total flavonoid content also decreased under elevated [CO2] in all rice milling fractions (8%–14%), with apigenin (25%) being highly affected in the white rice, and tricin (12%) in the bran. The same trend was found for γ-oryzanol, with decreases of 35%, 32%, 25%, and 2% in the white rice, brown rice, husk, and bran, respectively. In the white and brown rices, tocopherols and tocotrienols were all lower under elevated [CO2], with reductions larger for α-tocotrienol (69%), γ-tocotrienol (46%), and α-tocopherol (38%). Good correlations between antioxidant contents and DPPH radical scavenging capacities indicated that these decreases may be meaningful in the preventive ability of rice against free radical-mediated degenerative diseases.  相似文献   

10.
Folates (B vitamins) are essential for the proper function of many bodily processes. Although a rich natural source are vegetables, the literature lacks data on the effect of the pre-treatment and freezing technologies used in vegetable processing and frozen storage time on the folate content in these materials. Moreover, since folates are very unstable nutrients, the amount available in processed and stored foods can be significantly lower than in raw products. In tested vegetables (green beans, yellow beans, peas, cauliflower, broccoli and spinach), one folate form was identified, 5-methyltetrahydrofolate (5-CH3-H4folate). It was observed that pre-treatment and freezing technology significantly (p?<?0.05) decreased 5-CH3-H4folate content only in vegetables with the largest degree of fragmentation (cut and briquetted spinach) and the smallest size (peas). In all analyzed samples, the 5-CH3-H4folate content decreased with the time of frozen storage. In frozen cauliflower, the 5-CH3-H4folate loss exceeded 95 % compared to the fresh product just after the third month of frozen storage. Meanwhile, in green and yellow beans, significant 5-CH3-H4folate losses (at the level of 75 % and 95 %, respectively) were observed no earlier than after the 9th month of frozen storage.  相似文献   

11.
3 a试验结果表明:氮肥有利于增加分蘖和粒数,对产量起决定性作用,但不利于提高稻米品质;磷肥能够促进氮肥的吸收,增施磷肥有提高成熟度和增加产量的作用,同时又提高出米率和降低蛋白质含量;钾肥和镁肥对于产量影响不明显,但对改善稻米品质作用最明显。氮、磷、钾配施产量最高,增产6.3%,米质趋中,如果再加施镁肥,既有利于提高产量又有利于提高稻米品质。  相似文献   

12.
Potato tubers provide people not only with carbohydrates but also with other essential compounds for human health. Several investigations have compared the quality of crops grown under organic and conventional farming systems. The aim of the present study was to evaluate the concentrations of vitamins C, B1 and B2 as well as glycoalkaloids (α-solanine and α-chaconine) in potato tubers of different genotypes and to estimate the farming system (conventional and organic) impact on the content of these compounds. Twenty potato genotypes were grown under organic and conventional farming systems in Priekuli (Latvia) during 2010 and 2011. The concentrations of vitamins C, B1 and B2 as well as glycoalkaloids (α-solanine and α-chaconine) were significantly influenced by the potato genotype. The vitamin B1 concentration of potato genotypes grown in the organic field exceeded that of potato genotypes grown in the conventional field. A significant negative correlation was found between the vitamin C concentration and tuber yield only in the conventional field. No significant correlations were found between the other potato characteristics, such as starch content, tuber taste after boiling and glycoalkaloids, vitamins C, B1 and B2. The high broad-sense heritability for all tested traits (vitamin C 93%, vitamin B1 92%, α-solanine 88%, α-chaconine 84% and vitamin B2 70%) demonstrated that the high genetic diversity in the potato genotype population accounted for the phenotypic expression. The present study suggested that the breeding of new potato varieties with improved nutritional quality can be launched, and that the varieties that will be developed can be produced in an environmentally friendly way.  相似文献   

13.
Coeliac patients suffer from an immune mediated disease, triggered by the ingestion of a protein composite (gluten) found in wheat, rye and barley. Consequently, there is a need for products such as bread or pasta, made from alternative cereal grains or pseudocereals. A fair proportion of the gluten free products currently on the market are nutritionally inadequate. Hence, it was the aim of this study to investigate the nutrient composition of seven commonly used commercial gluten free flours (oat, rice, sorghum, maize, teff, buckwheat and quinoa) and compare them to wheat and wholemeal wheat flour. In addition to the levels of all major compounds, also mineral composition, fatty acid profile, phytate, polyphenols and folate content were determined. Furthermore, properties of carbohydrates were studied in greater detail, looking at total and damaged starch levels; total, soluble and insoluble dietary fibre content as well as amylose/amylopectin ratio. Proteins were further investigated by means of capillary electrophoreses. Additionally, the ultra-structure of these materials was explored using scanning electron microscopy. The results show that maize and rice flour are poor regarding their nutritional value (low protein, fibre, folate contents). In contrast, teff as well as the pseudocereals quinoa and buckwheat show a favourable fatty acid composition and are high in protein and folate. In particular, quinoa and teff are characterised by high fibre content and are high in calcium, magnesium and iron. Therefore these flours represent nutrient-dense raw materials for the production of gluten free foods.  相似文献   

14.
Previous studies identified type II inclusions in-situ of aleurone layers as niacin reserves and quantified niacin using colorimetric methods. Such identification and quantification was based on the König reaction which lacks specificity because cyanogen bromide reacts with all pyridine derivatives. The aim of this investigation was to define the structure of niacin in aleurone layers and aleurone cell contents of yellow corn, wheat and barley using LC–MS/MS. Aleurone layers were manually separated and cell contents released by ultrasonic processing and the residue and pellets were examined microscopically. Niacin was extracted from the samples by autoclaving in alkali. The extracts were analysed using HPLC and the structural identity of niacin was confirmed using quadrupole time of flight mass spectrometry in positive mode. Niacin concentrations were highest in wheat aleurone and lowest in corn aleurone. The MS/MS spectra of pure niacin and the purported niacin peak in sample extracts showed similar fragmentation patterns. The major ion product occurred at m/z 80 representing loss of CO2 and parent ion at m/z 124 (M + H)+. These findings define some of the structural characteristics of niacin in aleurone layer of cereal grains, and demonstrate the possibility of using an ultrasonic processor to release cell contents.  相似文献   

15.
Six legume crops and three cereal crops in the Asian Rice Farming Systems Network were compared with IR58 brown rice in terms of dry matter, energy and protein yields per hectare. Sorghum was closest to brown rice in dry matter and energy yield but soybean had the highest protein yield. Peanut and soybean had higher crude fat than the other crops which accounted for their high energy content and yield among the legumes. Amino acid analysis showed cowpea, mungbean, pigeonpea, bushsitao, and soybean protein as limiting in sulfur amino acids (cysteine + methionine). Peanut protein was limiting in either lysine or tryptophan + threonine. Corn, sorghum and wheat proteins were limiting in lysine.  相似文献   

16.
The effect of replacing wheat flour by infrared stabilized rice bran (SRB) at the levels of 2.5, 5.0 and 10.0% on the content of thiamine, riboflavin, niacin, pyridoxamine, pyridoxine, minerals and phytic acid in white wheat, wheat bran, and whole grain wheat breads was investigated. The incorporation of SRB significantly increased the amount of the noted B vitamins, especially niacin, in all bread types (p < 0.05). Zinc, iron, potassium and phosphorus levels of the breads increased gradually and significantly with the inclusion of SRB (p < 0.05). Moreover, phytic acid content of the breads increased proportional to the SRB substitution dose (p < 0.05).  相似文献   

17.
以玉米杂交种郑单958为试验材料,采用不同质量浓度50、100、200 mg/L的水溶性维生素V_(B1)、V_(B2)、V_(B6)、V_(B12)、V_C、V_H、V_(PP)浸种24 h,处理后分析玉米种子萌发及胚芽和根生长中脯氨酸等可溶性调节物质情况。结果表明,供试维生素在100、200 mg/L处理下基本都呈现对种子萌发指数的促进,其中,100 mg/L维生素处理对种子萌发率促进效果显著;200 mg/L维生素处理对种子发芽势显著促进作用;50 mg/L维生素对上述3个指标的影响不同。与未处理对照相比,不同种类维生素和不同质量浓度的同一维生素对根冠比影响不同。维生素浸种均可引起玉米胚芽可溶性糖含量显著升高,外源维生素浸种处理可显著影响玉米种子萌发和胚芽及胚根的生长,且不同维生素在不同浓度下对各生长指标影响及脯氨酸等可溶性调节物质变化不尽相同,对种子萌发呈显著促进作用的V_(B2)和V_(B12)在玉米种子萌发中应用前景较好。  相似文献   

18.
Total folate content was determined in the pseudocereals amaranth (four varieties), quinoa and buckwheat in comparison to four cereal species (eight wheat varieties, four barley varieties, one oat variety, one rye variety). Amaranth and quinoa were found to possess very high total folate contents: in amaranth, total folate ranged from 52.8 to 73.0 and in quinoa it was 132.7 μg/100 g dm, about ten times as much as in wheat. The bran fractions contained on average 124% of total folate, while only 57% on average was present in the flour fractions.  相似文献   

19.
应用无性系变异技术培育黑珍米的研究   总被引：4，自引：0，他引：4  
紫黑米的营养价值和药用功能早已被人们所认识,近年来,特种米的育种相继展开。1987年,我们从国际著名优质米Basmati 370体细胞无性系变异后代中发现了黑米突变体,经5代连续选育于1990年育成“黑珍米”,本文将其特征及成分与亲本作了初步比较。1 材料和方法以籼稻Basmati 370的成熟胚为起始材料,将脱壳的种子在75%酒精中浸泡1min,放入0.1%升汞溶液中灭菌20min后,用无菌水冲洗3～5次,再放入三角瓶中,每个三角瓶放100粒种子,振荡培养1～2d,当种胚萌动露白时接种在含2,4-D 2 mg/L和6-BA 2mg/L的N6固体诱导培养基上暗培养,当萌动幼胚  相似文献   

20.
The effects of moisture content （8%, 10%and 12%）, variety （Tarom and Fajr） and parboiling on milling quality of rice as a function of milling recovery （MR）, head rice yield （HRY）, degree of milling （DOM） and whiteness were investigated. The parboiled grains was prepared with three soaking temperatures of 25 oC, 50 oC and 75 oC and three steaming times of 10, 15 and 20 min. As a result of parboiling, the increasing rates of MR and HRY values were 7.8%and 14.3%for Tarom and 9.8%and 10.0%for Fajr, respectively, and the decreasing rates for DOM and whiteness were 6.6%and 10.8%for Tarom and 6.8% and 10.5% for Fajr, respectively. Moreover, decreasing moisture content to 8%maximized MR （75.8% for Tarom and 74.3% for Fajr） and HRY （65.8% for Tarom and 57.0% for Fajr） while increasing that to 12%revealed maximum values of DOM （6.1%for Tarom and 6.2%for Fajr） and whiteness （24.8%for Tarom and 28.2%for Fajr）.  相似文献   

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