Relationship Between Grain Hardness and Malting Quality of Barley (Hordeum vulgare L.)

In a three‐year period, protein content, polysaccharides and values of the selected malting parameters were determined in 12 varieties of barley. Hardness was assessed using the particle size index (PSI) and a Do‐Corder apparatus (BRA). Significant differences in the levels of hardness between the varieties were detected. Hardness was affected by variety from 37% (PSI) and 71% (BRA). Significant correlations were determined between the PSI and extract content (0.64^***), Kolbach index (0.66^***), friability (0.57^***), β‐glucans in wort (?0.51^***) and colour of malt (0.57^***). Significant correlations were found between BRA and content of non‐starch polysaccharides in caryopses (0.64^***), extract (?0.62^***), Kolbach index (?0.70^***), friability (?0.70^***), β‐glucans in wort (0.79^***) and wort colour (?0.56^***). Correlation was determined between hardness and malting quality index (PSI 0.51^***, BRA ?0.71^***).     

Starch Properties of a Waxy Mutant Line of Hull‐less Barley (Hordeum vulgare L.)

Endosperm starch isolated from an amylose‐free waxy mutant hull‐less barley line, Shikoku Hadaka 97, had an amylose content of 0.3% and higher swelling power than ordinary waxy barley cultivars/lines with amylose contents of 2.2—6.5%. A highly significant correlation was observed between amylose content and swelling power among waxy barley starches. No clear differences were detected in the chain‐length distribution profiles or thermal properties between the amylose‐free starch and ordinary waxy starch. The chain‐length distribution profile of waxy barley starch was slightly different from that of normal barley starch. Gelatinization temperatures and gelatinization enthalpy of waxy barley starch were higher than those of normal barley starch. Significant correlations were observed between amylose content and thermal properties of starch samples analyzed. Waxy barley starch stained with a concentrated iodine‐potassium iodide solution showed a ghost‐like appearance.     

Hypocholesterolaemic and antioxidant activities of chickpea (Cicer arietinum L.) protein hydrolysates

BACKGROUND: Some dietary proteins possess biological properties which make them potential ingredients of functional or health‐promoting foods. Many of these properties are attributed to bioactive peptides that can be released by controlled hydrolysis using exogenous proteases. The aim of this work was to test the improvement of hypocholesterolaemic and antioxidant activities of chickpea protein isolate by means of hydrolysis with alcalase and flavourzyme. RESULTS: All hydrolysates tested exhibited better hypocholesterolaemic activity when compared with chickpea protein isolate. The highest cholesterol micellar solubility inhibition (50%) was found after 60 min of treatment with alcalase followed by 30 min of hydrolysis with flavourzyme. To test antioxidant activity of chickpea proteins three methods were used: β‐carotene bleaching method, reducing power and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging effect since antioxidant activity of protein hydrolysates may not be attributed to a single mechanism. Chickpea hydrolysates showed better antioxidant activity in all assays, especially reducing power and DPPH scavenging effect than chickpea protein isolate. CONCLUSION: The results of this study showed the good potential of chickpea protein hydrolysates as bioactive ingredients. The highest bioactive properties could be obtained by selecting the type of proteases and the hydrolysis time. Copyright © 2012 Society of Chemical Industry     

Preparation and identification of peptides and their zinc complexes with antimicrobial activities from silver carp (Hypophthalmichthys molitrix) protein hydrolysates

The antibacterial activities of peptide–zinc complexes (PZCs) prepared from silver carp (Hypophthalmichthys molitrix) protein hydrolysates treated by four enzymes were evaluated. PZCs prepared from flavourzyme hydrolysates exhibited the highest antibacterial activities. The peptides that were able to produce PZCs with high antibacterial activity were isolated from flavourzyme hydrolysates using chromatographic procedures. Eleven peptides were identified through nano-liquid chromatography–electrospray ionization mass spectrometry. Five of these identified peptides were synthesized. The PZCs obtained were characterized and tested for antimicrobial activities. Results suggested that all five PZCs present strong antibacterial activities but no antifungal activities. Peptides with more acidic amino acid residues in their sequences could bind more zinc ions than peptides with fewer acidic amino acid residues. Zinc complexes of acidic amino acid-richer peptides showed stronger antibacterial activities. Results confirmed the antibacterial activities of PZCs from silver carp hydrolysates, and suggested the feasibility of PZCs as a provider of natural zinc ligands for antibacterial agents in the food and feed industries.     

Biological activity of barley (Hordeum vulgare L.) and barley by-product extracts

Barley and barley by-product extracts, waxy and non waxy genetic type, were prepared and investigated for its biological activity. The color, total phenolic contents, antioxidative activity, tyrosinase inhibition activity, xanthin oxidase inhibition activity, and angiotensin converting enzyme inhibition activity of the samples were measured. Hunter L* values of the by-products extract had higher than that of the whole and milled barley extracts. The contents of total phenolic compounds of the barley byproducts, waxy and non waxy type, were 18.60 and 17.92 mg/g of sample, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of waxy type whole, milled barely, and barley by-product extracts were 65.43, 30.84, and 54.62%, respectively. Inhibition rates (%) of the mushroom tyrosinase of the waxy type whole barley, milled barley, and barley by-products extracts powder were 26.76, 16.30, and 33.60% at 250 ppm, respectively. The samples showed an inhibition effect of xanthin oxidase and angiotensin converting enzyme.     

大麦酚类化合物及相关酶类的研究进展

大麦作为重要的粮食作物和啤酒酿造原料,其中的酚类化合物及其相关酶类（如酚类合成酶——苯丙氨酸解氨酶,酚类氧化酶——过氧化物酶和多酚氧化酶）对大麦的生长发育起重要的调节和保护作用,而在大麦的加工过程中会影响产品质量,如过氧化物酶和多酚氧化酶的氧化产物（苯醌和聚合产物）直接影响食品的质量。本文综述了大麦籽粒中酚类化合物及相关酶的种类和功能,并分析了对食品工业和啤酒酿造的影响。     

大麦总多酚不同溶剂提取物对DPPH自由基清除能力的影响

酚类化合物是大麦中主要的抗氧化物质之一,直接影响到麦芽、麦汁和啤酒的品质.研究了体积分数100%的甲醇、体积分数8O%的甲醇、体积分数8O%的乙醇、体积分数8O%的丙酮和水等5种不同提取溶剂对大麦游离多酚和结合多酚提取率的影响,以及不同溶剂提取物清除DPPH自由基能力的差异.结果表明:提取溶剂对大麦多酚的提取效率有显著影响,不同溶剂提取物清除DPPH自由基的能力有显著性差异;其中以80%丙酮溶液为提取溶剂时,所得提取物的游离多酚质量分数及其对DPPH自由基清除率最高,可作为大麦抗氧化物质的提取溶剂;不同品种大麦间游离总多酚质量分数及其对DPPH自由基清除率存在显著差异;结合Folin-Ciocaheu法和DPPH自由基清除率法分剐测定大麦总多酚质量分数和抗氧化力,可初步评价大麦原料的抗氧化特性.＃     

Selected Geometric and Mechanical Properties of Barley (Hordeum Vulgare L.) Grain

The properties of grain of Mauritia and Prestige barley varieties were determined for moisture content of 12.5 and 15.5% wet basis. Broad variations were observed in the relationship between the moisture content of grain, its variety, and the geometric properties of barley. Most of the geometric properties of barley were dependent on both the cultivar studied and the moisture content of grain, while selected characteristics were dependent on moisture content of grain or barley cultivar only. The values of displacement, force and energy required for kernel rapture were lower for Mauritia variety than Prestige variety and were not dependent on the moisture content of grain.     

Starch granule-associated proteins of hull-less barley (Hordeum vulgare L.) from the Qinghai-Tibet Plateau in China

BACKGROUND: The starch granule‐associated proteins (SGAPs) are the minor components of the starch granules and a majority of them are believed to be starch biosynthetic enzymes. The Qinghai‐Tibet Plateau in China, one of the centres of origin of cultivated barley, is abundant in hull‐less barley resources which exhibit high polymorphism in SGAPs. RESULTS: The SGAPs of hull‐less barley from Qinghai‐Tibet Plateau were analysed by one‐dimensional (1‐D) SDS‐PAGE, 2‐D PAGE and ESI‐Q‐TOF MS/MS. In the 1‐D SDS‐PAGE gel, four proteins including a 80 kDa starch synthase, actin, actin 4 and ATP synthase β‐subunit were identified as novel SGAPs. A total of six different bands were identified as starch granule‐bound starch synthase I (GBSSI) and the segregation of the novel GBSSI bands in F₁ and F₂ seeds derived from yf127 × yf70 was in accordance with Mendel's law. In the 2‐D PAGE gel, 92 spots were identified as 42 protein species which could be classified into 15 functional groups. Thirteen protein species were identified as SGAPs for the first time and multiple spots were identified as GBSSI. CONCLUSION: This study revealed novel SGAPs in hull‐less barley from the Qinghai‐Tibet Plateau in China and these will be significant in further studies of starch biosynthesis in barley. Copyright © 2011 Society of Chemical Industry     

大米肽中压离子交换色谱分离及其免疫活性评价

为进一步提高经过DA201-C型大孔吸附树脂脱盐、40%乙醇梯度洗脱的大米免疫活性肽RPHs-A3组分的纯度和免疫活性,采用中压离子交换色谱对其进行进一步分离纯化,并对分离得到组分的免疫活性进行了评价。结果表明,采用WorkBeads 40Q强阴离子交换树脂、2.6cm×40cm色谱柱对RPHs-A3组分进行分离的最佳条件为:上样浓度30mg/mL,上样量5 mL,起始缓冲液A为pH 9.0的0.01mol/L Tris-HCl,洗脱缓冲液B为含1 mol/L NaCl的pH 9.0、0.01 mol/L Tris-HCl,上样、洗脱流速分别为1,10mL/min。共收集到5个组分,其中RPHs-A3-B3组分在MTT试验和小鼠巨噬细胞脂多糖(LPS)炎症模型中皆表现出较高免疫活性,对RAW264.7细胞具有显著增殖作用,其SI值为1.315;且对炎症模型中细胞内NO释放量具有显著抑制作用(P0.05),抑制率为8.28%。采用中压离子交换色谱能有效地对RPHs-A3组分进行分离纯化,使SI值从1.273提高到1.315,且对细胞内NO释放量具有显著抑制作用。     

Isolation and identification of angiotensin-converting enzyme inhibitory peptides from egg white protein hydrolysates

The aim of this study was to identify potential angiotensin I-converting enzyme (ACE) inhibitory peptide from egg white protein. The protein was hydrolysed by Alcalase and the hydrolysates were isolated with Gel filtration to get the high activity fraction. The fraction was identified by LC tandem mass spectrometric 4000 Q Trap MS. In the current work, 19 peptides were discovered in the fractions, five of which sourced from ovotransferrin and were synthesised by Fmoc solid phase method. ACE-inhibitory activity was measured by HPLC assay. The 50% inhibitory concentrations of Arg–Val–Pro–Ser–Leu (RVPSL) was 20 μM. Based on this remarkable ACE-inhibitory activity, it is suggested that RVPSL may have potential applications as a functional food, which could be used as nutraceutical compounds.     

COMPARISON OF PEROXIDASES FROM BARLEY KERNEL (Hordeum vulgare L.) AND WHEAT GERM (Triticum aestivum L.): ISOLATION AND PRELIMINARY CHARACTERIZATION

Peroxidases (POD) of crude extracts from barley and wheat germ were separated, partially purified using salt fractionation, ion-exchange and hydrophobic interaction chromatographies and their properties examined. Barley and wheat germ POD contained basic, neutral and anionic isoforms as confirmed by isoelectric focusing. Toyopearl-Butyl 650 M chromatography resolved POD into four cationic fractions. Chromatography of wheat germ extract on CM-Sepharose isolated an anionic and a neutral fraction. Following chromatography on Concanavalin-A Sepharose, enzymes from both cereals showed differences in their elution properties. Optimum pH ranges were 4.0 to 5.5 (barley) and 5.3 to > 6.3 (wheat germ) and POD reacted differently under acidic or basic conditions. Their catalytic behavior in the presence of calcium also differed. Kinetics of POD were of Michaelian type with a ping-pong mechanism and Michaelis constants of guaiacol oxidation in the presence of hydrogen peroxide varied from one enzymatic group to another.     

The yields of extracted leaf protein from lucerne (Medicago sativa L.)

The effects of fertilisers, frequency of cutting, row spacing and simazine on the yields of dry matter and extractable protein from lucerne (Medicago sativa L.) were studied using the laboratory-scale pulper and press. Between 40 and 65% protein nitrogen was extractable; extractability was not affected by the various treatments but altered with season. Lucerne responded with increased yields of dry matter and extractable protein to fertilisers, simazine (35 g/ha) and rows spaced at 30.5 cm. Six or 8 harvests were found to give greater yields than 5 harvests in 180 days. The annual yields of extractable protein reached 3100 kg/ha and it is felt that better control of pests could lead to even greater yields.     

Effect of nitrogen fertilisation on protein content,total fatty acid content and composition of barley (Hordeum vulgare L.) grains

The impact of N-fertilisation level on protein content, total fatty acid (TFA) content and major fatty acid composition of barley grains (cv. Eldorado), grown in a replicated field trial, was investigated. Increasing amounts of N-fertiliser, applied at several stages during the growing season, resulted in a higher protein content and a very slightly lowered TFA content in the grains. Protein and TFA contents were negatively correlated (r=-0.4685). Minor changes of fatty acid composition were found in the decrease of the oleic acid (C18:1) proportion (r=-0.8376) and in the increase of the palmitic acid (C16:0) proportion (r=0.7273). The stearic acid (C18:0) and the linoleic acid (C18:2) proportions were also affected, however, no significant linear correlations with the total N-fertiliser level were obtained. The slow increase in the linolenic acid (C18:3) proportion (r=0.5674) was too small, compared to the residual variance, to be significant. TFA content was positively (P<0.001) correlated with the oleic acid proportion, and negatively (P<0.001) with the palmitic acid proportion. These data suggest that the application of higher amounts of N-fertiliser slightly decreases the total fatty acid content of barley grains, probably due to a decreased synthesis of oleic acid, precursor of the unsaturated C18 fatty acids. The result is a relative increase in palmitic acid.