Changes in the phenolic compound content and antioxidant activity in developmental maize kernels and expression profiles of phenolic biosynthesis-related genes

Phenolic compounds have various nutritional and functional properties, especially antioxidant activity. The objective of this study was to explore the relationship between the phenolic compound accumulation, antioxidant property and gene expression during maize kernel development. In this study, we explored the effects of developmental stage on the accumulation of phenolic compounds and their antioxidant activities. The expression levels of genes involved in phenolic biosynthesis were also studied. The results showed that the total phenolic content (TPC) and total anthocyanin content (TAC) were gradually increased from 15 to 48 days after pollination (DAP), whereas the total flavonoid content (TFC) decreased continuously. The antioxidant activity of maize kernels was increased gradually and positively associated with TPC. ZmCHSs in flavonoid biosynthetic pathway played important roles for total flavonoid accumulation at both early and later development stages. The expression pattern of ZmANS corresponded to the accumulation of total anthocyanin during kernel development. These results revealed that developmental stage affected the accumulation of different phenolic compounds, antioxidant activity and related gene expression. The antioxidant activity of maize kernels was dependent on the total phenolic accumulation which was related to the expression profiles of the genes participated in phenolic synthesis.     

Far infrared irradiation alters total polyphenol,total flavonoid,antioxidant property and quercetin production in tartary buckwheat sprout powder

The effects of far infrared irradiation (FIR) on total polyphenol (TP), total flavonoid (TF) content, antioxidant properties and aglycone quercetin production in tartary buckwheat sprout (TBS) were investigated. The study showed that FIR treatment decreased the total antioxidant capacity and metal chelating property in TBS in a temperature dependent manner, however, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity increased with the temperature. Similarly, TP and TF content also increased with temperature. The HPLC result revealed that quercetin production was directly proportional to the temperature, and the maximum production (average 14.8 mg/g dw) of quercetin was at 120 °C which was 13.5 times higher than the untreated control sample of TBS. Overall, this research is expected to be helpful to improve the nutritional value of tartary buckwheat by optimizing the FIR conditions.     

Total phenolic contents and antioxidant properties of buckwheat fermented by three strains of Agaricus

The aim of this work was to evaluate the effects of solid-state fermentation (SSF) with three strains of Agaricus (Agaricus blazei Murrill SH26, Agaricus bisporus AS2796 and Agaricus bisporus G1) on the total phenolic contents and antioxidant properties of buckwheat (Fagopyrum esculentum Möench). The results showed that the total phenolic contents of the fermented buckwheat varied with fermentation time and the starter organisms. The total phenolic content of buckwheat fermented with strain SH26 reached its maximum value of 18.07 mg/g after the fermentation of 21 days, which was 3.96 times higher than that of control. The ethanolic extracts of buckwheat fermented by strains SH26 and AS2796 exhibited enhanced antioxidant properties in comparison with the control. However, the ethanolic extracts of buckwheat fermented by strain G1 exhibited less antioxidant properties in comparison with the control. The ethanolic extracts of buckwheat fermented with strain SH26 exhibited the highest reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and ferrous ion chelating ability, respectively. The ethanolic extracts of buckwheat fermented with strain AS2796 exhibited the highest superoxide anion radical scavenging ability.     

Increasing the Antioxidant Activity,Total Phenolic and Flavonoid Contents by Optimizing the Germination Conditions of Amaranth Seeds

The aim of this study was to optimize the germination conditions of amaranth seeds that would maximize the antioxidant activity (AoxA), total phenolic (TPC), and flavonoid (TFC) contents. To optimize the germination bioprocess, response surface methodology was applied over three response variables (AoxA, TPC, TFC). A central composite rotable experimental design with two factors [germination temperature (GT), 20–45?ºC; germination time (Gt), 14–120 h] in five levels was used; 13 treatments were generated. The amaranth seeds were soaked in distilled water (25 °C/6 h) before germination. The sprouts from each treatment were dried (50 °C/8 h), cooled, and ground to obtain germinated amaranth flours (GAF). The best combination of germination bioprocess variables for producing optimized GAF with the highest AoxA [21.56 mmol trolox equivalent (TE)/100 g sample, dw], TPC [247.63 mg gallic acid equivalent (GAE)/100 g sample, dw], and TFC [81.39 mg catechin equivalent (CAE)/100 g sample, dw] was GT?=?30?ºC/Gt?=?78 h. The germination bioprocess increased AoxA, TPC, and TFC in 300–470, 829, and 213 %, respectively. The germination is an effective strategy to increase the TPC and TFC of amaranth seeds for enhancing functionality with improved antioxidant activity.     

High pressure processing manipulated buckwheat antioxidant activity,anti-adipogenic properties and starch digestibility

Effect of high pressure processing (HPP) on buckwheat nutritional properties is investigated in this study. The results indicated that the digestion of buckwheat starches of untreated and HPP treated at room temperature (RT) showed an “internal corrosion” pattern. However, an “exocorrosion” digestion behavior was observed for the starches of HPP treated sample at 45 °C, which might be due to the formation of amylose–lipid complexes during the process as revealed by X-ray diffraction (XRD). HPP treatment at 45 °C increased the antioxidant activity of the buckwheat as measured using 1,1′-diphenyl-2-picrylhydrazylvalue (DPPH) and iron chelating capacity (ICC) compared to untreated sample (P < 0.05), which might be associated with the release of bound phenolic compounds. More importantly, this is the first study to investigate the ability of buckwheat extract for inhibiting the formation of fat droplets using a C3H10T1/2 mesenchymal stem cell line, and found that the extract of buckwheat after HPP treatment at 45 °C demonstrated significant anti-adipogenic effects. This study suggested the HPP treatment at an increased temperature (45 °C) achieved a better nutritional value of the buckwheat than both untreated and treated at RT.     

Antioxidant properties of wheat mill streams

Knowing the quality of mill streams is very important for getting flours with improved quality. In the present work, 49 mill streams, obtained by milling common wheat with an industrial roller mill, were characterized in terms of phenolic content, antioxidant activity and iron content. The antioxidant activity was estimated using different methods: DPPH-radical scavenging, Trolox equivalent antioxidant capacity, and iron reducing antioxidant power. The break tailings and first tailings of the reduction passages had the largest contents of iron. The total phenolic contents (TPC) from flour streams ranged between 76.3 and 369 mg ferulic acid equivalent/100 g d.w. The highest TPC were obtained for the second fractions resulting from 1st and 2nd break rolls. The highest antioxidant activity was registered for flour streams collected from: the last two break rolls, the reduction rolls that process the tailings of the first three reduction passages and bran finisher. Trolox equivalent antioxidant capacity had the same trend as DPPH-radical scavenging activity. The highest iron reducing antioxidant power was found in the tailings of the reduction rolls. The knowledge provided by this study could be successfully applied for getting flour with improved antioxidant activity and iron content by mixing different types of mill streams.     

Antioxidant Capacity and Phenolics Content of Apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) Kernel as a Function of Genotype

Fourteen apricot genotypes grown under similar cultural practices in Trans-Himalayan Ladakh region were studied to find out the influence of genotype on antioxidant capacity and total phenolic content (TPC) of apricot kernel. The kernels were found to be rich in TPC ranging from 92.2 to 162.1 mg gallic acid equivalent/100 g. The free radical-scavenging activity in terms of inhibitory concentration (IC₅₀) ranged from 43.8 to 123.4 mg/ml and ferric reducing antioxidant potential (FRAP) from 154.1 to 243.6 FeSO₄.7H₂O μg/ml. A variation of 1–1.7 fold in total phenolic content, 1–2.8 fold in IC₅₀ by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and 1–1.6 fold in ferric reducing antioxidant potential among the examined kernels underlines the important role played by genetic background for determining the phenolic content and antioxidant potential of apricot kernel. A positive significant correlation between TPC and FRAP (r = 0.671) was found. No significant correlation was found between TPC and IC₅₀; FRAP and IC₅₀; TPC and physical properties of kernel. Principal component analysis demonstrated that genotypic effect is more pronounced towards TPC and total antioxidant capacity (TAC) content in apricot kernel while the contribution of seed and kernel physical properties are not highly significant.     

Enhancement of biologically active compounds in germinated brown rice and the effect of sun-drying

Germinated brown rice (GBR) has been suggested as an alternative approach to mitigate highly prevalent diseases providing nutrients and biologically active compounds. In this study, the content of γ-oryzanol, γ-aminobutyric acid (GABA), total phenolic compounds (TPC) and antioxidant activity of soaked (for 24 h at 28 °C) and GBR (for 48 and 96 h at 28 °C and 34 °C) were determined and the effect of sun-drying as an economically affordable process was assessed. Germination improved the content of GABA, TPC and antioxidant activity in a time-dependent manner. Sun-drying increased γ-oryzanol, TPC and antioxidant activity, whereas GABA content fluctuated depending on the previous germination conditions. This study indicates that sun-drying is an effective sustainable process promoting the accumulation of bioactive compounds in GBR. Sun-dried GBR can be consumed as ready-to-eat food after rehydration or included in bakery products to fight non-communicable diseases.     

Evaluation of Antioxidant Capacity and Phenol Content in Jackfruit (Artocarpus heterophyllus Lam.) Fruit Pulp

The antioxidant capacity of jackfruit (Artocarpus heterophyllus Lam. Fam. Moracae) fruit pulp (JFP) obtained from Western Ghats India was determined by evaluating the scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing power assays and N, N-dimethyl-p-phenylendiamine (DMPD) radical cation decolorization assay. JFP was analyzed for total phenolic content (TPC) and total flavonoids content (TFC). The ethanol and water are the best solvents for the extracting phenols and flavonoids from the JFP. The antioxidant activities of JFP extracts were correlated with the total phenolic and flavonoids content. The results indicated that the jackfruit pulp is one natural source of antioxidant compounds.     

Contribution of flavonoids to the antioxidant properties of common and tartary buckwheat

The objective of this study was to characterize the flavonoid compounds found in the different grain parts of common and tartary buckwheat, and to determine the contribution of these flavonoids to the antioxidant properties of buckwheat. Eight flavonoid compounds were quantified and their antioxidant activity determined by FRAP, DPPH, and ABTS assays. Of the flavonoid compounds identified rutin was the most abundant, particularly in tartary buckwheat, in which it comprised approximately 90% of total flavonoid content. Flavan-3-ols were detected in common but not tartary buckwheat, and quercetin was detected only in tartary buckwheat. Flavonoid content—in particular, levels of rutin, orientin, and/or epicatechin gallate—was found to influence the total antioxidant activity of buckwheat. Results from this study indicate that antioxidant activity is not only closely associated with flavonoid content, but that different flavonoids contribute differently to the total antioxidant activity of common and tartary buckwheat.     

Superfine grinding improves functional properties and antioxidant capacities of bran dietary fibre from Qingke (hull-less barley) grown in Qinghai-Tibet Plateau,China

The effect of particle size of hull-less barley (HLB) bran DF on antioxidant and physicochemical properties was investigated. HLB bran and extracted DF was ground by regular and superfine grinding, their particle sizes were determined using laser diffraction method. The results showed that superfine grinding could significantly pulverize DF particles to micro-scale; the particle size distribution was close to a Gaussian distribution. The soluble DF in HLB bran was increased effectively with superfine grinding. Insoluble DF with submicron scale showed increased total phenolic content (TPC), DPPH radical scavenging activity and ferric reducing antioxidant power (FRAP). With particle size reduction, the water retention capacity (WRC), swelling capacity (SC), oil binding capacity (OBC), and nitrite ion absorption capacity (NIAC) were significantly (p < 0.05) increased and the water holding capacity (WHC) had no significant change. A kind of health beneficial DF with higher soluble DF content, WRC, SC, OBC, NIAC and antioxidant activity was obtained using superfine grinding.     

烘焙速度对兴隆咖啡豆挥发性成分的影响

以海南兴隆地区咖啡豆（Coffea robusta）为研究对象,研究不同烘焙方式（即快速烘焙、中速烘焙以及慢速烘焙）对咖啡豆理化性质和挥发性成分的影响,采用顶空固相微萃取-气相色谱-质谱联用技术（headspace solid-phase microextraction-gas chromatograph-mass spectrometry,HS-SPME-GC-MS）鉴定3种烘焙速度下产生的挥发性成分,再以电子鼻技术和主成分分析（principal component analysis,PCA）法进一步分析不同烘焙豆样品整体风味的差异。结果表明,3种烘焙方式下共鉴定出92种挥发性成分,其中快速、中速和慢速烘焙豆中分别鉴定出82、72、76种;烘焙豆样品间挥发性成分含量相差较大,在中速烘焙豆中检测出最高的挥发性成分总含量（1080.51 μg/g）;电子鼻检测发现不同烘焙方式咖啡豆挥发性成分存在差异,PCA结果显示三者差异明显,其中中速和慢速烘焙样品的挥发性成分有部分重叠现象,二者与快速烘焙样品差别较大。本研究可为咖啡烘焙工艺改进及品质提升提供参考。     

Effect of sucrose on antioxidant activities and other health-related micronutrients in gamma-aminobutyric acid (GABA)-enriched sprouting Southern Vietnam brown rice

Improving the nutritional quality of germinated brown rice (GBR) is important for the population consuming rice as part of the daily diet to offer health benefits. In this study, a set of popularly grown 79 rice varieties in Southern Vietnam was evaluated to identify the potential materials for producing gamma-aminobutyric acid (GABA)-enriched GBR. Enhancing antioxidant components, antioxidant activities, and other health-promoting micronutrients by sucrose treatment were also investigated in both white and red GBR. The results indicated that OM457 (white rice) and TN11 (red rice)-derived GBR had the highest GABA content of 105.68 mg GABA/100 g F.W and 47.68 mg GABA/100 g F.W among investigated rice varieties, respectively. Sucrose at 50 mM, in general, boosted total phenolic compounds, total flavonoids, anthocyanin content, thereby increasing antioxidant activities in both these GBR. Moreover, GC-MS-based metabolomic analysis indicated that GABA accumulation under sucrose treatment was rice pericarp/variety-specific. Also, sucrose stimulated the accumulation of other health-benefiting metabolites and free sugars. Altogether, the results in this study indicate that sucrose is an effective elicitor for improving the nutritional value in GBR, facilitating for production of ready-to-eat GBR with health-promoting benefits.     

Compositional,functional and storage properties of flours from raw and heat processed African breadfruit (Treculia africana Decne) seeds

African breadfruit (Treculia africana Decne) seeds were either boiled or roasted and then milled into flour. Chemical composition, functional properties and storage characteristics of raw and treated flours and the effect of partial proteolysis on selected functional properties of the raw flour were determined. Raw flour contained 20.1% crude protein, 2.5% total ash and 13.7% fat. Heat processing significantly (p<0.05) improved in vitro protein digestibility, and water and fat absorption capacities but decreased bulk density, nitrogen solubility, emulsion and foaming properties, trypsin inhibitor, and phytic acid and polyphenol contents of the samples. Boiling proved more effective than roasting for improving protein digestibility, emulsion capacity and foam stability and reducing antinutritional factor levels. Partial proteolysis increased nitrogen solubility, bulk density and water and fat absorption capacities but decreased foam capacity at hydrolysis levels greater than 35%. Fatty acid and peroxide values of the samples increased during storage. Compared to raw samples, heat processed samples had significantly (p<0.05) lower and more acceptable peroxide values and free fatty acid contents and higher and more stable water (3.0 g/g sample) and fat (2.4 g/g sample) absorption capacities.     

Effects of Roasting on Phenolic Composition and In vitro Antioxidant Capacity of Australian Grown Faba Beans (Vicia faba L.)

Faba bean phenolic compounds encompassed phenolic acids, flavonols, proanthocyanidins and anthocyanins. Roasting faba beans for 120 min decreased the total phenolic, flavonoid and proanthocyanidin contents by 42, 42 and 30 %, respectively. Roasting beans for 120 min decreased the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, total equivalent antioxidant capacity and ferric reducing antioxidant power by 48, 15 and 8 %, respectively. High performance liquid chromatography-post column derivatisation revealed the generation of new phenolic compounds as a result of roasting. Antioxidant mechanism of bean less-polar phenolic compounds was largely based on free radical scavenging activity. The bean phenolic compounds with reducing capability were heat stable. Roasted faba bean extracts (70 % acetone, v/v) were fractionated into relatively polar and non-polar fractions; the latter contributed the majority of the antioxidant capacity. The extracts from beans with different seed coat colours differed in their phenolic compositions, which suggest different levels of potential benefits to health. Although roasting initially lowers the bean antioxidant capacity, prolonged roasting at 150 °C for 60 min and longer causes generation of new phenolic compounds and an increased antioxidant capacity. The findings encourage a wider ultilisation of faba beans for human foods particularly in baked/roasted products.     

Physicochemical and antioxidant properties of extruded corn grits with corn fiber by CO2 injection extrusion process

Corn grits and corn fiber mixed at different mass ratios (0/100, 15/85 and 30/70) were extruded at different melt temperature (90, 105 and 120 °C) using extrusion with and without CO₂ injection. The L value, reducing sugar content and antioxidant properties decreased after extrusion with or without CO₂ injection. The color and antioxidant properties were relatively stable in the extrusion with CO₂ injection at higher melt temperature (120 °C) in comparison with the extrusion without CO₂ injection. Higher corn fiber content resulted in less loss of total phenolic content. The b, ΔE values and water absorption index increased after extrusion. The increase of the water absorption index was higher after the extrusion process with the CO₂ injection especially at the lower melt temperature. The addition of corn fiber decreased L, b, and ΔE values, but significantly increased antioxidant properties under the same extrusion conditions.     

Effects of roasting and storage on proteins and oil in peanut kernels

Peanut kernels, untreated or soaked in salt solution, were roasted at 160°C for 30 min in a hot air oven or oil roasted at 147°C for 2 min and, stored at 27°C and 5°C up to 150 days. The heat treatments significantly decreased methionine, tryptophan and in vitro protein digestibility (IVPD) and, increased the soluble proteins and acid value of kernel oil. Storage of heated peanuts caused an increase in water-soluble proteins, IVPD, acid value and saponification value and a decrease in methionine, tryptophan and iodine value. The oil roasting was found to be more detrimental to nutritional quality and storage stability of peanuts as compared to dry roasting. The storage of heated peanuts at 5°C was found to be beneficial in lowering the undesirable nutritional changes in the peanut kernels.     

Assessment of antioxidant activity and rheological properties of wheat and buckwheat milling fractions

This study examined the antioxidant properties of the ethanolic extracts of wheat milling fractions (wheat flour type 500 and type 850, and bran) and their polyphenol and tocopherol content, and rheological characteristics of wheat dough supplemented with buckwheat flours (light and wholegrain). The results obtained in this study were correlated with our previously published data on wheat flour type 400, wholegrain wheat flour and buckwheat flours.Buckwheat flours exhibited significantly higher (P < 0.05) antiradical activity on hydroxyl (OH), superoxide anion (O₂⁻) and (1,1-diphenyl-2-picrylhydrazyl) DPPH radicals, antioxidant activity and reducing power than all investigated wheat milling fractions when their corresponding IC₅₀ values were compared.The rheological parameters of wheat dough supplemented with light and wholegrain buckwheat flour (0-50%) were obtained by using Mixolab. Results indicated changes in protein and starch properties of dough.The obtained results indicate the benefit of using buckwheat flours in wheat-based food products, i.e. their contribution in functional and tailor-made-food production.     

Hydrothermal and biotechnological treatments on nutraceutical content and antioxidant activity of rice bran

The effect of processing such as steaming, germination and parboiling on nutraceuticals and in vitro bioactive properties of rice bran from three different rice varieties namely Jyothi (pigmented), IR64 and Sona masuri (non-pigmented) were investigated. Within the varieties envisaged, pigmented Jyothi variety contained higher levels of vitamin E, soluble, bound and total polyphenol, flavanoids, free radical scavenging activity and total antioxidant activity. Direct steam exposure of bran resulted in an increase in, ether extractives and oryzanol, as well as retention of all the vitamin E components, bound polyphenols, flavonoids and decrease in soluble and total polyphenol content, free radical scavenging activity and total antioxidant activity compared to native. Parboiling as well as germination of paddy resulted in an increase, in the content of ether extractives and oryzanol, whereas other bioactive properties decreased compared to native. Hence it may be concluded that bioactive components and antioxidant properties were significantly higher in Jyothi bran compared to the other two paddy brans, and processing leads to changes in bioactive properties with maximum retention of bioactive components in the steamed bran.     

红树林植物海莲不同部位提取物抗氧化活性研究

植物抗氧化研究对寻找高效率、低毒性天然抗氧化剂具有重要的指导意义。以在海南分布较广的红树林植物海莲进行抗氧化活性研究,以期对海莲开发利用的可能性提供理论依据。采用清除DPPH自由基和清除ABTS自由基对海莲不同部位———根、茎、叶、花的乙酸乙酯提取物进行抗氧化能力评价,采用比色法和福林酚法测定总黄酮和总酚含量。结果显示,海莲茎的提取物在4个部位中抗氧化活性最好,清除二者的IC50分别为(0.234±0.053)mg/m L和(0.196±0.080)mg/m L,海莲中酚类物质含量较大,4个部位中茎的总酚含量最多,含量为13.2 mg。说明海莲各部位均显示出了较好的抗氧化能力,具有较好的开发潜力。