Anthocyanin composition in black, blue, pink, purple, and red cereal grains

Anthocyanin pigments from a wide variety of edible and ornamental black, blue, pink, purple, red, and white wheat, barley, corn, rice, and wild rice were identified and quantified to evaluate their potential as natural colorants or functional food ingredients. The total anthocyanin contents varied significantly and exhibited a range of 7-3276 microg/g. Some grains, such as red rice and black rice, contained a limited number of pigments, whereas others, such as blue, pink, purple, and red corns, had complex anthocyanin profiles. Of the 42 anthocyanin compounds observed, 9 were characterized by comparison of the spectroscopic and chromatographic properties with those of authentic standards. The remaining compounds were tentatively identified on the basis of spectroscopic properties and electrospray ionization mass spectra. The most abundant anthocyanins were cyanidin 3-glucoside in black and red rices and in blue, purple, and red corns, pelargonidin 3-glucoside in pink corn, and delphinidin 3-glucoside in blue wheat.     

蓝、紫粒小麦光合特性的研究

以西南地区的白粒小麦品种("绵阳26"和"川麦107")为对照,对新育成的蓝、紫粒小麦品种(系)在不同发育时期的光合色素含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间CO2浓度(Ci)等光合特性进行比较分析。结果表明,蓝、紫粒小麦叶片叶绿素a、叶绿素b和总叶绿素含量和对照的白粒小麦一样,均随孕穗期、抽穗期、开花期、灌浆期和成熟期的发育进程而下降,在孕穗期含量最高,成熟期含量最低;蓝粒小麦的叶绿素a、叶绿素b和总叶绿素含量在各发育时期均最低;白粒小麦的叶绿素a和总叶绿素含量在除孕穗期外的各发育时期最高,成熟期的叶绿素b含量也最高。白粒小麦叶片中类胡萝卜素含量随发育进程一直下降,直至成熟,而紫粒和蓝粒小麦在开花期前逐渐下降,但开花期后又逐渐升高,成熟时达到最大值;灌浆期和成熟期类胡萝卜素含量最高的是蓝粒小麦,其次是紫粒小麦,白粒小麦最低。蓝、紫粒小麦和白粒小麦的净光合速率均随发育进程呈先升后降的变化趋势,开花期净光合速率最大;白粒小麦在除灌浆期外的其他生育期净光合速率最大,蓝粒小麦在开花期后净光合速率是最低的。蓝、紫粒小麦和白粒小麦的气孔导度和蒸腾强度均随发育进程呈单峰曲线变化,峰值出现在灌浆期。白粒小麦的气孔限制值在孕穗期到开花期低于紫粒和蓝粒小麦,而开花期后则高于紫粒和蓝粒小麦。新近育成的几个蓝、紫粒小麦的光合能力低于白粒小麦。     

Comparison of black,purple, and yellow barleys

Many barley landraces are purple-or black-seeded, but the chemical composition of these purple-and black- seeded barley is rarely examined. Therefore, studies were conducted to determine if the chemical composition of purple and black barleys differs from that of yellow barleys. Four sets of genetic materials were used for these studies: 96 doubled-haploid (DH) lines, 10 near-isogenic lines, 40 landraces, and four F3 bulks. The results showed that purple DH lines contained a similar amount of lignin as yellow DH lines and that anthocyanin-containing isogenic lines did not differ from anthocyanin-free lines in lignin content. Therefore, these results suggest that anthocyanin biosynthesis is independent of lignin biosynthesis in barley. The results also showed that black barley contained more protein and more lignin than yellow barley in two crosses and that among the 40 landraces studied, the three with the highest concentration of lignin happened to be black seeded. Lignin content was not associated with seed weight except in defective endosperm lines. The presence of pigments and a relatively high concentration of lignin might help reduce the level of kernel blight severity in black barley. More studies are needed to determine the chemical composition and pest resistance associated with purple and black barleys.     

Aging, free radicals, and antioxidants in wheat seeds

Free radical oxidative attack is considered a major cause of disruption and deteriorative changes observed in aged seeds. Antioxidant defense mechanisms may remove potentially damaging molecular species, and carotenoids may act as radical scavengers. The content of lutein, the major carotenoid in wheat seeds, was determined in the flours. It showed a rapid decrease during seed aging. In addition, the content of free radicals in glutens made from flours of wheat seeds after long-term storage was studied. The concentration of radicals appeared to be age dependent, because the highest content of radicals was detected between 13 and 15 years of aging over 36 years of storage. Specific spin labeling of the sulfhydryl groups of gluten proteins enabled comparative EPR studies of the rigidity of the protein chains. A progressive stiffening of polymeric gluten with seed storage was found.     

Phytochemicals and antioxidant activity of milled fractions of different wheat varieties

The health-promoting effects of whole-grain consumption have been attributed in part to their unique phytochemical contents and profiles that complement those found in fruits and vegetables. Wheat is an important component of the human diet; however, little is known about the phytochemical profiles and total antioxidant activities of milled fractions of different wheat varieties. The objectives of this study were to investigate the distribution of phytochemicals (total phenolics, flavonoids, ferulic acid, and carotenoids) and to determine hydrophilic and lipophilic antioxidant activity in milled fractions (endosperm and bran/germ) of three different wheat varieties, two of which were grown in two environments. Grain samples of each of the wheat varieties were milled into endosperm and bran/germ fractions. Each fraction was extracted and analyzed for total phenolics, ferulic acid, flavonoids, carotenoid contents, and hydrophilic and lipophilic antioxidant activities. Total phenolic content of bran/germ fractions (2867-3120 micromol of gallic acid equiv/100 g) was 15-18-fold higher (p < 0.01) than that of respective endosperm fractions. Ferulic acid content ranged from 1005 to 1130 micromol/100 g in bran/germ fractions and from 15 to 21 micromol/100 g in the endosperm fractions. The bran/germ fraction flavonoid content was 740-940 micromol of catechin equiv/100 g. On average, bran/germ fractions of wheat had 4-fold more lutein, 12-fold more zeaxanthin, and 2-fold more beta-cryptoxanthin than the endosperm fractions. Hydrophilic antioxidant activity of bran/germ samples (7.1-16.4 micromol of vitamin C equiv/g) was 13-27-fold higher than that of the respective endosperm samples. Similarly, lipophilic antioxidant activity was 28-89-fold higher in the bran/germ fractions (1785-4669 nmol of vitamin E equiv/g). Hydrophilic antioxidant activity contribution to the total antioxidant activity (hydrophilic + lipophilic) was >80%. In whole-wheat flour, the bran/germ fraction contributed 83% of the total phenolic content, 79% of the total flavonoid content, 51% of the total lutein, 78% of the total zeaxanthin, 42% of the total beta-cryptoxanthin, 85% of the total hydrophilic antioxidant activity, and 94% of the total lipophilic antioxidant activity. Our results showed that different milled fractions of wheat have different profiles of both hydrophilic and lipophilic phytochemicals. These findings provide information necessary for evaluating contributions to good health and disease prevention from whole-wheat consumption.     

Phytochemical composition, anti-inflammatory, and antiproliferative activity of whole wheat flour

Whole wheat flour from five wheat cultivars was evaluated for phenolic, carotenoid, and tocopherol compositions as well as anti-inflammatory and antiproliferative activities against HT-29 cells. The total ferulic acid content ranged from 452 to 731 μg/g among the five cultivars and was primarily present in the insoluble-bound form. Lutein was the only carotenoid detected and ranged from 1.5 to 4.0 μg/g, and α-tocopherol levels ranged from 12 to 61 μg/g. Extracts of four cultivars demonstrated significant anti-inflammatory activity, measured as inhibition of interleukin-1β (IL-1β) mRNA expression; however, none of the extracts inhibited tumor necrosis factor-α (TNF-α) mRNA expression, a second indicator of anti-inflammatory activity. Proliferation of HT-29 adenocarcinoma cells was inhibited by extracts from all cultivars at the dose of 100 mg botanical equivalent/mL. The cultivar WestBred 936 had the greatest antiproliferative activity at lower concentrations (20 and 50 mg botanical equivalent/mL), had the greatest anti-inflammatory effect against IL-1β, and also had the highest levels of ferulic acid and α-tocopherol. This research shows that whole wheat flours of these five cultivars varied significantly in their contents of phenolics, carotenoids, and α-tocopherol as well as in their anti-inflammatory and antiproliferative potentials, suggesting the possibility that wheat varieties can be selected based on potential health benefits.     

黑碳在杉木人工林土壤不同组分中的分配规律研究

黑碳(BC)是土壤惰性 C 库的重要组分,在土壤 C 循环中占有重要地位.本文利用相对密度分组方法研究BC在杉木人工林土壤不同组分中的分配规律.结果表明:杉木人工林土壤轻组分中黑碳(LFBC)含量为 0.05 ～ 0.64 g/kg,而重组分中黑碳(HFBC)含量为 0.23 ～ 1.09 g/kg.LFBC/BC的比例为 12.9% ～ 37.5%,HFBC/BC的比例为62.5% ～ 87.1%,表明 BC 主要存在重组分中.但是,LFBC含量占轻组有机碳(LFOC)含量的比例(LFBC/LFOC)为4.0% ～ 27.9%,而HFBC含量占重组有机碳(HFOC)含量的比例(HFBC/HFOC)仅为 6.5% ～ 8.9%,前者比例大多高于后者,说明轻组分中不仅存在 BC,而且 BC 占该组分 C 库的比例较高.     

Synthesis of antioxidants in wheat sprouts

Aqueous and ethanolic extracts from wheat (Triticum aestivum) sprout powder were analyzed to determine its reduction and antioxidant activities. Mean and standard deviation of five independent samples were reported. The results showed that the micromoles of potassium ferricyanide reduced by aqueous and ethanolic extracts corresponding to 1 g of sprout powder (80.6 +/- 11.2 and 9.7 +/- 1.8, respectively) were higher than that reduced by 1 mg of other reducing compounds: ascorbic acid, rutin, quercetin, and reduced gluthatione (4.8 +/- 0.7, 3.8 +/- 1.2, 4.8 +/- 1.7, and 1.6 +/- 0.4, respectively). In addition, the oxygen superoxide scavenging activity performed by sprout extracts (from 1 g of powder) is comparable to that shown by 10 mg of antioxidant pure compounds (rutin and quercetin). Biochemical analysis of the sprout extracts shows that the antioxidant activity is mainly due to reducing glycoside and polyphenolic compounds.     

Phytochemical profiles and antioxidant activity of wheat varieties

Whole grain consumption has been associated with reduced risk of chronic diseases, such as cardiovascular diseases and cancer. These beneficial effects have been attributed to the unique phytochemicals of grains that complement those found in fruits and vegetables. Wheat is one of the major grains in the human diet; however, little is known about the inherent varietal differences in phytochemical profiles, total phenolic and carotenoid contents, or total antioxidant activities of different wheat varieties, which ultimately influence the associated nutritional and health benefits of wheat and wheat products. The objectives of this study were to determine the phytochemical profiles and total antioxidant activity for 11 diverse wheat varieties and experimental lines. The profiles included free, soluble-conjugated, and insoluble-bound forms of total phenolics, flavonoids, and ferulic acids and carotenoid content including lutein, zeaxanthin, and beta-cryptoxanthin. The results showed that total phenolic content (709.8-860.0 micromol of gallic acid equiv/100 g of wheat), total antioxidant activity (37.6-46.4 micromol of vitamin C/g), and total flavonoid content (105.8-141.8 micromol of catechin equiv/100 g of wheat) did not vary greatly among the 11 wheat lines. However, significant differences in total ferulic acid content (p < 0.05) and carotenoid content (p < 0.05) among the varieties were observed, with carotenoid content exhibiting the greatest range of values. Carotenoid content among the 11 wheat varieties exhibited 5-fold, 3-fold, and 12-fold differences in lutein, zeaxanthin, and beta-cryptoxanthin, respectively. A synthetic wheat experimental line, W7985, gave the lowest carotenoid concentrations of any of the genotypes in this study. Such large genotypic differences in carotenoid content may open up new opportunities for breeding wheat varieties with higher nutritional value.     

不同基因型小麦铁营养效率差异及其可能机制

采用营养液培养试验对苗期6个不同小麦基因型旱选10,鲁麦14,小偃54,京411,洛夫林和中国春的铁营养效率进行了研究,并对其可能机制进行了探讨。试验设低铁(2μmol/L)和正常铁(100μmol/L)2个处理。结果表明,小麦的铁营养效率存在基因型差异,其范围从58%到92%。供试基因型中铁营养效率最高的基因型为中国春,最低的为旱选10。本试验条件下,小麦种子中铁浓度与其苗期铁营养效率间未发现相关性。多重回归分析表明,小麦铁营养效率差异主要由铁吸收决定,而铁吸收主要由根表面积差异决定。说明具有较大根表面积的小麦基因型在苗期具有更高的铁营养效率与抵抗铁缺乏的能力。     

Zinc fractions in soil and uptake by wheat as affected by different preceding crops

Zinc (Zn) deficiency is widespread in alkaline and calcareous soils. Limited information is available on the effect of preceding crops on the distribution of Zn in soil solid phase. This field study was conducted to investigate the changes in Zn chemical forms in soil solid phase as affected by four preceding crops [Sunflower (Heilianthus annuus L. cv. Allstar), Sorghum (Sorghum bicolor L. cv. Speed Feed), Clover (Trifolium pratense L.) and Safflower (Carthamus tinctorius L. cv. Koseh-e-Isfahan)] in a calcareous soil. A control treatment with no preceding crop (fallow) was also used. Our results showed that the preceding crops increased Zn concentration in exchangeable fraction (EXCH-Zn), the organically bound zinc form (ORG-Zn) and zinc bound to iron and manganese oxides (FeMnOX-Zn) while decreased carbonates bound-zinc (CAR-Zn) and residual zinc forms (RES-Zn). However, the changes in Zn fractions were dependent on the preceding crop type. The EXCH-Zn and ORG-Zn pools can be considered labile pools that play significant roles in supplying Zn for plants. Among the preceding crops used in this experiment, clover (Clo) had the highest effect on transforming CAR-Zn form to EXCH-Zn and ORG-Zn labile forms and thus resulted in the highest Zn accumulation in tissues of the target wheat (Triticumaestivum L. cv. Back Cross). Although the changes in chemical forms of Zn in the soil solid phase are complex and dependent on various factors, our findings showed that the preceding crops significantly increased the concentration of Zn in exchangeable and organic matter pools and in turn resulted in higher uptake of Zn by the target wheat.     

Phytochemical and dietary fiber components in barley varieties in the HEALTHGRAIN Diversity Screen

Ten different barley varieties grown in one location were studied for their content of tocols, folate, plant sterols, alkylresorcinols, and phenolic acids, as well as dietary fiber components (arabinoxylan and beta-glucan). The samples included hulled and hull-less barley types and types with normal, high-amylose, and waxy starch. The aim was to study the composition of raw materials, and therefore the hulls were not removed from the hulled barleys. A large variation was observed in the contents of all phytochemicals and dietary fibers. Two varieties from the INRA Clermont Ferrand barley program in France (CFL93-149 and CFL98-398) had high content of tocopherols and alkylresorcinols, whereas the variety Dicktoo was highest in dietary fiber content and phenolics. Positive correlations were found between 1000 kernel weight, alkylresorcinols, and tocols, as well as between dietary fiber content and phenolic compounds. The results demonstrate that the levels of phytochemicals in barley can likely be affected by breeding and that the contents of single phytochemicals may easily be adjusted by a right selection of a genotype.     

Radical scavenging activity of a purple pigment, hordeumin, from uncooked barley bran-fermented broth

A novel purple pigment called hordeumin, a type of anthocyanin-tannin pigment, was produced from barley bran-fermented broth. The radical scavenging activity of hordeumin was analyzed by using an electron-spin resonance (ESR) spectrometer. The hordeumin scavenged superoxide radical in a concentration-dependent manner. Superoxide dismutase-like activity values were 118 and 195 units/mg for crude and partially purified hordeumin, respectively. The two types of hordeumins also scavenged the DPPH radical. Furthermore, barley bran-fermented filtrate before pigment formation and extract of barley bran also scavenged the DPPH radical. However, the DPPH radical scavenging activity of a filtrate, fermented over a long period, was stronger than that fermented over a short period. Thus, it was considered that radical scavenging activity of hordeumin resulted from barley bran polyphenol such as proanthocyanidins.     

Bioactivity of antioxidants in extruded products prepared from purple potato and dry pea flours

Measuring antioxidant activity using a biologically relevant assay adds important evidence to aid in understanding the role of phytochemicals based on data from in vivo and chemical assays of extrusion processed purple potato and pea flours. A cellular antioxidant activity assay could provide biologically relevant information on bioactive compounds in raw as well as processed food products. The objective of this study was to investigate the complete phytochemical profiles, antioxidant activity, cellular antioxidant activity, and their contribution to bioactivity in purple potato flour, dry pea flour, raw formulations, and extrusion cooked products prepared with the above ingredients. The free fraction of extracts contributed 68, 64, and 88% to total phenolics, total antioxidant activity (ORAC value), and total flavonoids, respectively, in purple potato flour (PPF). Similarly, extracts in the free fraction contributed 87, 86, and 64% to total phenolics, total antioxidant activity (ORAC value), and total flavonoids, respectively, in dry pea flour (DPF). The amount of total phenolics and total flavonoids in purple potato flour and the antioxidant activity of PPF and DPF were comparable to published data. However, a higher amount in the total flavonoids and lower in the total phenolics of DPF were observed. Caffeic, p-coumaric, and ferulic acids were mostly observed in the bound extracts of raw formulations as in the extrudates, whereas chlorogenic acid was predominant in the free extracts. The extruded products had significantly higher (p < 0.05) content of total phenolics, ORAC antioxidant activity, and flavonoids, compared to the raw formulations. Extrusion processing increased the cellular antioxidant activity of the extrudates prepared from 35:65 and 50:50 PPF/DPF (w/w) of ingredients compared with control raw formulations in a dose-dependent manner. Increase of PPF significantly increased (p < 0.05) the cellular antioxidant activity of 35-50% PPF formulations.     

黑、紫粒小麦对氮素吸收及同化特性的初步研究

以3个不同类型小麦品种为试材,通过对幼苗期根系氮素吸收Vmax和Km的测定及灌浆期剑叶中NR、GS活性的比较分析,初步探讨了黑、紫粒小麦根系对氮素吸收的动力学和同化特性及其与营养品质间的相互关系。结果表明,同普通的白粒小麦相比,黑、紫粒小麦在对氮素的吸收、转运和同化等方面均具有较强的优势,这可能是其蛋白质等营养成分富积的主要原因之一。     

Stoichiometric and kinetic studies of phenolic antioxidants from Andean purple corn and red-fleshed sweetpotato

Stoichiometric and kinetic values of phenolics against DPPH (2,2-diphenyl-1-picrylhydrazyl) were determined for Andean purple corn (Zea mays L.) and red sweetpotato (Ipomoea batatas). Both crops had higher antioxidant capacity and antiradical kinetics than blueberries and higher or similar anthocyanin and phenolic contents. The second-order rate constant (k(2)) was 1.56, 1.12, 0.57, and 0.26 (mg antiradical/mL)(-1) s(-1) for red sweetpotato, Trolox, purple corn, and blueberry, respectively. On the molar basis of active hydroxyl groups, k(2)' showed the same order as for k(2). Corn cob and sweetpotato endodermis contributed the most in phenolic compounds and antioxidant capacity. Both crops studied can be considered as excellent novel sources of natural antioxidants for the functional food and dietary supplement markets.     

Growth response of barley and wheat to salt stress

Dry matter yield and water uptake by barley (Hordeum vulgare L., cv. ‘Gus') and wheat (Triticum aestivum L., cv. ‘Inia 66') grown in full strength Hoagland nutrient solution were compared under three NaCl salinity levels in a growth chamber. Total dry matter yield decreased with increasing salinity for both plants, but wheat was more severely affected than barley at the high salinity level. Reduction in dry matter weights of barley and wheat were 57% and 67%, respectively, at the 1.2 MPa stress. Salt stress substantially decreased the number of tillers in both crops, however, this reduction was more severe for wheat than barley. The numbers of tillers were 10 and 7 for barley plants at 0.6 and 1.2 MPa stress, respectively. The respective values were 6 and 4 for wheat plants. Water uptake in both plants was substantially decreased by increasing salinity stress. This reduction was essentially similar for both plants. Water uptake per gram dry weight was not significantly affected by salt stress for barley. For wheat, only 1.2 MPa stress increased the amount of water absorbed per g dry matter produced.     

Crop rotation effects on yield of oilseed rape,wheat and barley and residual effects on the subsequent wheat

Economic conditions are forcing farmers to grow crops with high revenue leading to cereal-dominated crop rotations with increasing risk due to unfavourable preceding crops or preceding crop combinations. Based on a long-term field trial (1988–2001) with 15 different rotations including winter oilseed rape (OSR), winter wheat, winter barley, spring peas and spring oats, the effects of different preceding crops, pre-preceding crops and crop rotations on the grain yield of mainly OSR, winter wheat and winter barley were quantified. In the subsequent 2 years (2001/2002 and 2002/2003), winter wheat was grown on all plots in order to test the residual effects of the former crops (as preceding crops in 2002 and as pre-preceding crops in 2003) and crop rotations on growth, grain yield and yield components.

Unfavourable preceding crops significantly decreased yield of OSR, wheat and barley by 10% on average, however, with a large year-to-year variation. In addition, break-crop benefits in both crops, wheat and OSR, persisted to the second year. Wheat as preceding crop mainly decreased the thousand grain weight, and to a lesser extent, the ear density of the subsequent wheat crop. The amount of wheat yield decrease negatively correlated with the simple water balance (rainfall minus evapotranspiration) in May–July. In 2001/2002 and 2002/2003, the preceding crop superimposed the crop rotation effects, thus resulting in similar effects as observed in 1988–2001.

Our results clearly reveal the importance of a favourable preceding crop for the yield performance of a crop, especially wheat and OSR.