Effects of water-saving superabsorbent polymer on antioxidant enzyme activities and lipid peroxidation in oat (Avena sativa L.) under drought stress

BACKGROUND: Drought stress significantly limits oat (Avena sativa L.) growth and productivity. Thus an efficient management of soil moisture and study of metabolic changes in response to drought are important for improved production of oat. The objective was to gain a better understanding of drought tolerance mechanisms and improve soil water management strategies using water‐saving superabsorbent polymer (SAP) at 60 kg ha^?1 under three irrigation levels (adequate, moderate and deficit) using a new type of hydraulic pressure‐controlled auto irrigator. RESULTS: The results showed that the relative water content and leaf water potential (ψ₁) were much higher in oats treated with SAP. Although the SAP had little effect on plant biomass accumulation under adequate and moderate irrigation, it significantly increased the biomass by 52.7% under deficit irrigation. Plants treated with SAP under deficit irrigation showed a significant decrease in superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and glutathione reductase activities in leaves compared with control plants. CONCLUSION: Our results suggested that drought stress leads to production of oxygen radicals, which results in increased lipid peroxidation and oxidative stress in the plant, and the application of SAP could conserve soil water, making same available to plants for increased biomass accumulation and reduced oxidative stress especially under severe water stress. Copyright © 2010 Society of Chemical Industry     

Effectiveness of a water-saving super-absorbent polymer in soil water conservation for corn (Zea mays L.) based on eco-physiological parameters

BACKGROUND: The objective was to study soil water conservation and physiological growth of corn (Zea mays L.) using water‐saving super‐absorbent polymer (SAP) at 30 kg ha^?1. The effectiveness of SAP was studied under three irrigation levels (adequate, moderate and deficit) using a new type of negative hydraulic pressure controlled auto‐irrigator in the years 2009 and 2010 in a greenhouse at Beijing, P.R. China. RESULTS: Eight weeks after sowing, plant height and leaf area increased significantly by 41.6 and 79.6% under deficit irrigation for SAP treatment. The SAP had little effect on shoot dry mass under adequate and moderate irrigation but increased it significantly by 133.5% under deficit irrigation. Similarly, the efficiency of water use also increased by 97.1%. Leaf water potential under adequate and moderate irrigation differs slightly for SAP application, whereas under deficit irrigation the values were exceeded significantly by 27.8%. The superior growth and water use efficiency of corn treated with SAP under deficit irrigation was ascribed to maintenance of higher relative water contents in leaves as well as intercellular carbon dioxide concentration, net photosynthesis and transpiration rate. CONCLUSIONS: Our results suggested that plant growth and different physiological activities are restricted by drought stress and the application of super‐absorbent polymer could conserve soil water, making same available to plants for increased growth and biomass accumulation especially under severe water stress. Thus, application of SAP is a suitable soil management practice for the locations characterised by severe water stress. Copyright © 2011 Society of Chemical Industry     

A lysimeter study of nitrate leaching, optimum fertilisation rate and growth responses of corn (Zea mays L.) following soil amendment with water-saving super-absorbent polymer

BACKGROUND: Nitrate leaching and the resulting groundwater contamination from intensive cereal production has become a major concern for long‐term farmland efficiency and environmental sustainability in northern China. The aim of this study was to evaluate a water‐saving super‐absorbent polymer (SAP) for minimising NO₃^? leaching from soil and optimising corn growth and yield. Thirty‐six undisturbed soil lysimeters were installed in a field lysimeter facility in drought‐affected northern China to study the growth and yield characteristics of summer corn (Zea mays L.) as well as the amount of NO₃–leaching losses under different fertiliser (standard, medium or 75% and low, or 50% of conventional fertilisation rate) and SAP (control, 0; level‐1, 15 kg ha^?1 and level‐2, 30 kg ha^?1) treatments. RESULTS: Corn yield fell by 19.7% under medium and 37.7% under low fertilisation; the application of SAP increased yield significantly by 44.4% on level‐1 and 80.3% on level‐2. Similarly, plant height, leaf area, number of grains as well as protein, soluble sugar and starch contents in the grain also increased with SAP treatment. Application of SAP at 30 kg ha^?1 plus half of conventional fertilisation can reduce maximum (64.1%) nitrate leaching losses from soil. CONCLUSIONS: Application of SAP at 30 kg ha^?1 plus only half the amount of conventional fertiliser rate (150 kg urea, and 50 kg each of superphosphate and potassium sulfate) would be a more appropriate practice both for minimising nitrate leaching and sustainable corn production under the arid and semiarid conditions of northern China. Copyright © 2011 Society of Chemical Industry     

Chemical characterization and antioxidant capacity in blue corn (Zea mays L.) malt beers

Corn has been widely used in traditionally fermented Mexican beverages. We recently developed a process to prepare beers using 100% pigmented corn varieties that provide polyphenols and anthocyanins with antioxidant properties. Moreover, new styles could be created when modifying the process conditions and ingredients. Thus, we explored the effect of caramel malt addition and different amounts of hops and guajillo chili, generating several styles of blue corn malt beers (BCMB). The objective was to evaluate these effects on selected chemical parameters and antioxidant properties at three different stages of the brewing process. To achieve this, base and caramel malts were obtained and used to develop eight styles of BCMB, using different concentrations of chili and hops, using an ale fermentation process. Eleven chemical properties were determined in the wort, green and mature beer of the eight styles of BCMB. Low‐alcohol beers were obtained and the values of total reducing sugars, alcohol, pH, total acidity, bitterness units and iso‐α ‐acids during the stages of the process were similar to barley beers. Additionally, anthocyanin concentration, polyphenols and antioxidant capacity decreased through the process stages. The interaction of the ingredients produced effects on the chemical composition and antioxidant activity in mature beers. After statistical analysis, by both univariate ANOVA and multivariate methods (hierarchical cluster analysis and principal component analysis), a higher concentration of anthocyanins and ABTS antioxidant capacity was founds in two beer styles that were formulated with 85% base malt and 15% caramel malt. Copyright © 2017 The Institute of Brewing & Distilling     

Extraction and identification of anthocyanin from purple corn (Zea mays L.)

An efficient extraction of anthocyanin from purple corn (Zea mays L.) was investigated in this paper. Tristimulus colourimetry was used to evaluate the process quantitatively and qualitatively. Purple corn anthocyanin was extracted with 1 n HCl–95% ethanol (15:85, v/v) at different extraction temperatures (30–70 °C), times (60–120 min) and solid–liquid ratio (1:20–1:40). The combined effects of extraction conditions on anthocyanin yield and colour attributes were studied using a three‐level three‐factor Box–Behnken design. The results showed that the highest yield of anthocyanin from purple corn (6.02 mg g^?1) were obtained at 70 °C, extraction time 73 min, and solid–liquid ratio 1:25. Three kinds of non‐acylated anthocyanins were detected and characterised as cyanidin‐3‐glucoside, pelargonidin‐3‐glucoside and peonidin‐3‐glucoside by HPLC‐MS.     

Fumonisins in corn (Zea mays L.) from Southern Brazil

A total of 232 samples of corn commercialised in Santa Catarina state, Southern Brazil (temperate zone climate), were evaluated from 2007 to 2012 for fumonisins (FBs: FB₁ and FB₂). Before performing this study, a FBs method with liquid chromatography and fluorescence detection (ex. 335; em. 440 nm) was validated first. FBs were detected in 46.6% (108 samples), with values ranging from 66 to 7832 µg kg^?1 for FB₁ and 110 to 1201 µg kg^?1 for FB₂. The number of contaminated corn samples for FB₁ and FB₂ varied and often presented contamination of FB₁ only. Per year of analysis, the numbers were: n = 22/8(FB₁/FB₂), 44/5(FB₁/FB₂), 25/12(FB₁/FB₂), 4(FB₁), 6(FB₁) and 7(FB₁) in 2007, 2008, 2009, 2010, 2011 and 2012, respectively. The contamination percentage was 42.3/15.4, 59.5/6.8, 43.8/21.1, 36.4, 35.3 and 33.3%, respectively, during these years. Consumers can be exposed to these mycotoxins and their health can be at risk through the consumption of contaminated corn.     

Short communication: Effects of feeding purple corn (Zea mays L.) silage on productivity and blood superoxide dismutase concentration in lactating cows

The objective of this study was to evaluate the effects of feeding purple corn (Zea mays L.) silage on productivity and blood superoxide dismutase concentration in lactating cows. We hypothesized that feeding purple corn silage (AX-152; Nagano Animal Industry Experiment Station, Nagano, Japan, and Takii and Co. Ltd., Tokyo, Japan), which is high in anthocyanin content, would increase milk production and blood concentration of superoxide dismutase. We assigned 16 Holstein cows (8 primiparous and 8 multiparous) in mid lactation to 1 of 2 treatments in a randomized block design, with efforts to balance parity, body weight, and days in milk between treatments. Experimental diets contained either purple corn silage [PCS; 31.2% dry matter (DM), 8.4% crude protein, 40.2% neutral detergent fiber, and 26.6% starch] or conventional corn silage (CONT; 30.5% dry matter, 8.7% crude protein, 42.1% neutral detergent fiber, and 26.5% starch) at approximately 32% of diet DM. Both PCS and CONT were ensiled for 5 mo before the study. Treatment diets were fed as total mixed rations ad libitum for 12 wk from February 1 to April 25, 2016. Cows fed the PCS had increased milk yield (31.7 vs. 29.2 kg/d) and blood superoxide dismutase concentrations (9,333 vs. 8,467 U/mL) compared with those fed CONT. However, anthocyanin concentration in the PCS decreased over the 12-wk experiment: 70 mg/kg of DM for the first 4 wk, 20 mg/kg of DM for the second 4 wk, and undetectable for the last 4 wk. We did not detect anthocyanins in the CONT group at any time point. Feeding PCS may increase antioxidant capacity and milk production in dairy cows, but anthocyanin in PCS may be degraded during storage.     

真菌固态发酵对玉米抗氧化性影响

采用两株食品常用真菌(米根霉3.1175和3.2751)固态发酵玉米,研究发酵前后这2株真菌对玉米抗氧化成分以及抗氧化活性的影响。测定了发酵前后玉米中的总酚和总黄酮;并通过氧自由基吸收能力(ORAC)法和循环伏安法测定了发酵前后抗氧化活性。结果发现玉米中总酚含量、抗氧化活性在米根霉3.2751的发酵下得到显著提高(p<0.05),而其黄酮含量在发酵前后变化不显著(p>0.05)。米根霉3.1175发酵的玉米,总酚含量、黄酮含量、ORAC法抗氧化活性变化不显著(p>0.05),循环伏安法抗氧化活性显著下降(p<0.05)。因此米根霉3.2751发酵的玉米相对未发酵玉米具有更好的抗氧化活性。     

Short communication: Purple corn (Zea mays L.) stover silage with abundant anthocyanins transferring anthocyanin composition to the milk and increasing antioxidant status of lactating dairy goats

The present study used 16 multiparous lactating Saanen dairy goats (body weight, 41.80 ± 2.92 kg; mean ± standard deviation) with healthy and symmetrical udders. Goats were divided into 2 blocks of 8 goats based on milk yield averaged from 75 d in milk in a randomized completed block design. The 2 study groups were the control (CSSS), in which goats were fed sticky corn stover silage, and the treatment (TPSS), in which goats were fed anthocyanin-rich purple corn (Zea mays L.) stover silage (PSS). The results indicated that the TPSS group led to an elevation in the content of milk lactose relative to the CSSS. The inclusion of anthocyanin-rich PSS had no effect on the level of 5 particular anthocyanins [i.e., cyanidin-3-glucoside, delphinidin, cyanidin, pelargonidin (Pel), as well as total anthocyanins in milk]. The pelargonidin-3-glucoside and malvidin were unable to be detected in both groups. However, the TPSS resulted in higher levels of peonidin (Peo) and malvidin-3-O-glucoside (M3G) compared with the control. Moreover, goats receiving TPSS exhibited a higher level of superoxide dismutase (SOD) in plasma and milk relative to the CSSS. Interestingly, some positive correlations were detected between the certain milk components [i.e., fat and total solids as well as fat and solids-not-fat (SNF); protein and SNF; and total solids and SNF]. In addition, the positive correlations were observed between individual anthocyanins (cyanidin-3-glucoside, delphinidin, Peo, M3G, cyanidin, and Pel) and total anthocyanins. Specifically, stronger positive correlations were noted between several antioxidant enzymes and anthocyanin composition in milk (total antioxidant capacity and Pel; SOD and Peo as well as SOD and M3G). Taken together, PSS with abundant anthocyanins can transfer anthocyanins to the milk and enhance the amount of antioxidants in lactating dairy goats.     

Polyphenolic and antioxidant content of white and blue corn (Zea mays L.) products

The polyphenolic and antioxidant content of white, Mexican blue, and American blue corns processed into nixtamal (cooked kernels), tortillas, and chips was investigated. A post-nixtamalization acidification treatment was assessed as a means to reduce polyphenolic and antioxidant losses. Similar anthocyanin composition (cyanidin 3-monoglycosides) and concentration (314 mg/kg) was observed for both blue corn genotypes as was their non-anthocyanin polyphenolic composition ((+)-catechin, free and esterified ferulic acid, and p-coumaric acid derivatives). Six derivatives of ferulic acid (88.8–816 mg/kg) along with the free form (2480 mg/kg), p-coumaric acid (6.6 mg/kg), two protocatechuic acid derivatives (4.2 and 14.2 mg/kg), and gallic acid (3.9 mg/kg) were identified in the white genotype. Both blue genotypes contained higher antioxidant capacity (>8.3 μmol Trolox equivalents/g) yet lower polyphenolic levels (3.6–4.4 g/kg) than the white genotype. Comparable anthocyanin losses were observed when the blue genotypes were processed into nixtamals (37%), tortillas (54%), and chips (78%) that correlated to polyphenolic (r = 0.91) and antioxidant capacity (r = 0.94) losses. Acidification was mainly effective in reducing anthocyanin (9–17%), polyphenolic (10%), and antioxidant capacity (6–14%) losses for the blue genotypes. This study compared polyphenolic and antioxidant content among corn genotypes and confirmed that acidification post-nixtamalization could reduce polyphenolic and antioxidant losses.     

Polyphenol composition and antioxidant activity of cumin (Cuminum cyminum L.) seed extract under drought

This research evaluated the effect of drought on total and individual polyphenol contents as well as the antioxidant activities of cumin (Cuminum cyminum L.) seeds of 2 geographic origins, Tunisia (TCS) and India (ICS). Plants were treated with different levels of water deficit: control. Our results indicated that, in both varieties, moderate water deficit (MWD) improved the number of umbels per plant as well as the number of umbellets per umbel and the seed yield, in comparison to the control, but it decreased under severe water deficit (SWD). Besides, total phenolic contents were higher in the treated seeds and drought increased the level of total and individual polyphenols. This increase was appreciably more important in TCS than in ICS. Moreover, antioxidant activities of the extracts were determined by 4 different test systems, namely 2,2-diphenyl-1-picrylhydrazyl, β-carotene/linoleic acid chelating, and reducing power assays, and showed that treated seeds exhibited the highest activity, for both TCS and ICS.     

干旱胁迫对山葡萄叶片膜质过氧化和保护酶活性的影响

研究了不同干旱水平对4个山葡萄品种双丰、双优、左山一和左山二叶片膜质过氧化和抗氧化酶活性的影响.结果显示:山葡萄遭遇干旱胁迫时发生膜质过氧化作用,干旱程度越重,MDA累积量越大;SOD活性呈现整体先升高后降低的趋势,但双丰升高不明显,降低显著.双丰、左山一和左山二的POD活性先升高后降低,双优POD活性一直降低.贝达作为对照,随干旱胁迫程度的增强,其MDA含量逐渐增加,而SOD和POD活性变化幅度较小,SOD始终保持在较高的活性状态,POD则一直呈升高的趋势.     

Utilisation of corn (Zea mays) bran and corn fiber in the production of food components

The milling of corn for the production of food constituents results in a number of low‐value co‐products. Two of the major co‐products produced by this operation are corn bran and corn fiber, which currently have low commercial value. This review focuses on current and prospective research surrounding the utilization of corn fiber and corn bran in the production of potentially higher‐value food components. Corn bran and corn fiber contain potentially useful components that may be harvested through physical, chemical or enzymatic means for the production of food ingredients or additives, including corn fiber oil, corn fiber gum, cellulosic fiber gels, xylo‐oligosaccharides and ferulic acid. Components of corn bran and corn fiber may also be converted to food chemicals such as vanillin and xylitol. Commercialization of processes for the isolation or production of food products from corn bran or corn fiber has been met with numerous technical challenges, therefore further research that improves the production of these components from corn bran or corn fiber is needed. Published 2010 by John Wiley & Sons, Ltd.     

D-氨基半乳糖改性对玉米谷蛋白结构性质及抗氧化活性的影响

为了提高玉米谷蛋白的水溶性,采用谷氨酰胺转氨酶(TGase)和D-氨基半乳糖对玉米谷蛋白进行糖基化改性,研究了糖基化改性对原玉米谷蛋白结构性质及抗氧化活性的影响。红外光谱的测定结果表明,在TGase的催化下,玉米谷蛋白与D-氨基半乳糖发生了共价结合。与玉米谷蛋白相比,D-氨基半乳糖的共价结合使玉米谷蛋白的游离氨基含量增加158 mmol/kg·蛋白,热变性温度和变性焓分别降低9.03℃和68.74 J/g,即糖基化改性使玉米谷蛋白的结构变得无序而松散,热稳定降低;同时,糖基化改性使玉米谷蛋白对3种自由基(包括DPPH、羟基和超氧阴离子)的清除活性、对Fe2+的螯合能力以及还原力等显著提高,尤其是Fe2+螯合活性,其EC50值减少了1.27 mg/mL。试验结果表明酶法糖基化是一种适合于对玉米谷蛋白进行改性的有效方法。     

Accumulation of phenolics,antioxidant and antiproliferative activity of sweet corn (Zea mays L.) during kernel maturation

Phenolic profiles and gene expression pattern in their synthetic pathway, total antioxidant activities and antiproliferative activities in two genotypes of sweet corn (YT16 and YT28) during kernel maturation were analysed. Results showed that increasing trends of phenolics and flavonoids in the two genotypes of kernels from 10 to 30 days after pollination (DAP). Gallic acid, chlorogenic acid, p-coumaric acid and ferulic acid were identified and quantified as the main phenolic compounds in both genotypes of kernels. High expressing levels of C4O and PAL resulted in the increasing phenolic contents. Higher expressing levels of CHS in YT28 led to higher flavonoid contents than that in YT16. The phenolic contents, antioxidant capacities and antiproliferative abilities of the two genotypes of sweet corn were competitive comparing to many fruits and vegetables. In addition, the maturation process of sweet corn could raise the kernel’s bioactive ability as well as nutritional values.     

Evaluation of carotenoid biosynthesis,accumulation and antioxidant activities in sweetcorn (Zea mays L.) during kernel development

To have a better understanding of regulatory mechanism of carotenoid accumulation in sweetcorn (Zea mays L.), we analysed carotenoid profiles, expression patterns of carotenogenic genes and antioxidant activities in two genotypes of sweetcorn during kernel development. The results suggested that the expression of carotenogenic genes played an essential role in carotenoid accumulation and higher expression levels of carotenogenic genes obviously led to higher levels of total carotenoids. It was found that the expression of upstream genes (_ZmPDS, _ZmZDS and _ZmCRTISO) had major influence on the content of total carotenoid during kernel development. The accumulation of lycopene was closely related to the coordination of upstream and downstream genes. The expression of _ZmHYD and _ZmZEP was influential on zeaxanthin accumulation, which was also influenced by the rate of _ZmCHYB/_ZmCHYE. Expression levels of _ZmCHYE were still stable in order for α‐xanthophylls largely accumulated during kernel development. Lutein, zeaxanthin, α‐cryptoxanthin and β‐cryptoxanthin constituted the predominant carotenoids in sweetcorn. Two essential stages for carotenoid accumulation were found in sweetcorn during kernel development.