Preharvest application of methyl jasmonate increases fruit quality and antioxidant capacity in raspberries

The effects of preharvest methyl jasmonate (MJ) application on fruit quality, flavonoid content and antioxidant capacity in black raspberry cv. Jewel (Rubus occidentalis L) and red raspberry cv. Autumn Bliss (Rubus idaeus subsp.) were studied under field condition. Raspberries treated with MJ had higher soluble solids content, total sugars, fructose, glucose, sucrose and lower titratable acids (TAs), malic acid and citric acid than untreated fruit. MJ also significantly enhanced the content of flavonoids and the antioxidant capacities in the fruit. The cv. Jewel had higher soluble solids and lower TAs compared with the cv. Autumn Bliss. On the basis of fresh weight of fruit, ‘Jewel’ also had significantly higher anthocyanin, total phenolic content and antioxidant activity than ‘Autumn Bliss’.     

Physicochemical Properties and Antioxidant Capacity of Chinese Olive (Canarium album L.) Cultivars

In this study, the physicochemical characteristics and antioxidant potentials of 10 Chinese olive cultivars were investigated. Considerable differences were found between cultivars in weight, edible yield, water content, size, shape, total soluble solids, and total titratable acidity. The major sugars and organic acids in all the cultivars were glucose, fructose, and malic acid. Phenolics were the most abundant antioxidants (1174.0 to 1799.6 mg gallic acid equivalents/100 g fresh weight). Twelve phenolic compounds were identified and quantified by UPLC‐MS/MS. Six compounds were identified first in the Chinese olive, with 3‐O‐galloylquinic acid and geraniin isomers as the most abundant compounds. The results also indicated that the phenolic content (TPC) correlated with the antioxidant properties of Chinese olive fruit extracts. A principal component analysis indicated that the Tantou and Tanxiang cultivars were a valuable source, with high TPC and antioxidant activity, whereas Maken22, Changying, and Green changying cultivars may be eaten fresh and had high sugar and low phenolic contents. This information will be useful for selecting suitable cultivars for industry and the market.     

PHYTOCHEMICAL AND FATTY ACID PROFILE OF SELECTED RED RASPBERRY CULTIVARS: A COMPARATIVE STUDY

ABSTRACT

Seven red raspberry cultivars (Heritage, Canby, Willamette, Hollanda Boduru, Newburgh, Tulameen and Meeker) were evaluated for their total anthocyanin (TACY), total phenolics (TP), trolox equivalent antioxidant capacity (TEAC), fatty acids (FAs) and soluble sugars properties. The TACY, TP and TEAC content ranged from 171.5 to 475.0 µg/g fresh weight (fw), 864.4–1246.9 µg gallic acid equivalent/g fw and 19.4–32.7 µmol TE/g fw, respectively. The highest values of TACY, TP and TEAC content were obtained from the Newburgh cultivar. The FA compositions of raspberry cultivars ranged from 4.97 to 20.31% saturated FAs, 14.65–18.47% monounsaturated FAs (MUFAs) and 62.85–78.68% polyunsaturated FAs (PUFAs). Cultivars Meeker and Newburgh had the highest level of MUFAs, respectively, while the highest level of PUFAs was observed in cultivar Hollanda Boduru. The main soluble sugars of the seven raspberry genotypes were also separated, identified and quantified using high‐performance liquid chromatography with refractive index detection. According to the results, fructose, glucose and sucrose were detected as the main soluble sugars, while xylose and mannose were not detected in the raspberry fruits.

PRACTICAL APPLICATIONS

There have been no previous studies comparing the fruit quality characteristics of raspberry cultivars. Raspberries may be a good alternative crop with a high market value, especially highly profitable due to the long harvesting period, because of the ideal climatic conditions. The objective of this work was to evaluate seven red raspberry cultivars in terms of their total anthocyanin, total phenolic, antioxidant capacity, fatty acids profile and soluble sugar properties.     

Nondestructive Evaluation of Quality Changes and the Optimum Time for Harvesting During Jujube (<Emphasis Type="Italic">Zizyphus jujuba</Emphasis> Mill. cv. Changhong) Fruits Development

Jujube fruit is an increasingly important fruit in the world for its high nutrients content and the harvest time is crucial for jujube fruit quality. The aim of the study was to evaluate the quality changes and the optimum time for harvesting of jujube fruit (Zizyphus jujuba Mill. cv. Changhong) by chlorophyll fluorescence. Our results showed that jujube fruit cv. Changhong displayed a double sigmoid growth curve with a very short lag phase. At the last three ripening stages (72, 80, and 88 days after petal fall), Fo, Fm, and Fv showed positive and significant correlation with DPPH radical scavenging activity, total phenolic, reducing sugar, ascorbic acid, and total flavonoid (0.729 ≤ r ≤ 0.920, P < 0.05). However, pH, total soluble sugar and carotenoids showed negative and significant correlation with Fo, Fm, and Fv (−0.885 ≤ r ≤ −0.826). The last three ripeness stages in our study were differentiated using the chlorophyll fluorescence parameters. Therefore, chlorophyll fluorescence is a helpful, nondestructive technique to evaluate the quality changes and the optimum time for harvesting of Changhong jujube.     

低温真空膨化与自然干制对红枣抗氧化活性的影响

目的：研究低温真空膨化和自然干制对红枣抗氧化成分及活性的影响,为生产加工优质枣产品和低温真空膨化技术在红枣加工方面应用提供科学依据。方法：以矮化密植枣树所得枣果为材料,采用Folin-Ciocalteu与NaNO2-Al(NO3)3法测定总酚、总黄酮含量;通过DPPH自由基清除率、ABTS+•清除能力、总还原力和抗亚油酸过氧化能力等指标表征枣果抗氧化能力;采用高效液相色谱法对酚类化合物进行定性定量分析。结果：红枣经膨化后总酚含量显著增加,而总黄酮未发生明显变化,自然干制使总酚、总黄酮含量显著降低。膨化枣DPPH自由基清除能力和总还原力显著优于鲜枣和自然干制枣,自然干制处理使红枣ABTS+•清除能力和β-胡萝卜-亚油酸抗氧化活性显著低于膨化枣与鲜枣。膨化枣中总酚、总黄酮和抗氧化能力显著高于自然干制枣。干制处理使枣果中酚类化合物组成发生明显变化,膨化枣中没食子酸、对羟基苯甲酸、咖啡酸、对香豆酸、阿魏酸、芦丁、肉桂酸和槲皮素的含量最高。相关性研究表明鲜枣与干制枣中抗氧化活性与总酚、总黄酮显著相关。结论：低温真空膨化枣含有丰富的酚类化合物与最高抗氧化能力,且加工时间短,口感酥脆香甜。综上所述,低温真空膨化技术可作为一种可用于规模化干制枣的现代化加工技术。     

Phytochemical constituents and antioxidant capacity of different pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars

Six pecan cultivars were analyzed for their antioxidant capacity (AC), total phenolics (TP), condensed tannin (CT), HPLC phenolic profile, tocopherol and fatty acid composition. Kernels which included the outer brown testa or pellicle, and shells which is the hard cover that surrounds the kernel, were evaluated for each cultivar. Strong correlations were found in kernels between AC and TP for both DPPH (r² = 0.98) and AC_ORAC (r² = 0.75) antioxidant assays. AC_ORAC values ranged from 372 to 817 μmol trolox equivalents/g defatted kernel, corresponding to Desirable and Kanza cultivars, respectively. CT ranged from 23 to 47 mg catechin equivalents/g defatted kernel and TP from 62 to 106 mg of chlorogenic acid equivalents/g defatted kernel. After a consecutive basic-acid hydrolysis, gallic acid, ellagic acid, catechin and epicatechin were identified by HPLC. The TP, AC and CT were 6, 4.5 and 18 times higher, respectively, for shells compared to kernels. The presence of phenolic compounds with high antioxidant capacity in kernels and shells indicates pecans can be considered an important dietary source of antioxidants.     

不同成熟期灵武长枣酚类组分及抗氧化活性差异分析

对不同成熟期（白绿、微红、大半红、全红）灵武长枣酚类成分组成、含量及其活性的差异进行研究,以期发现不同成熟期灵武长枣抗氧化功能品质的变化规律。以宁夏不同成熟期的灵武长枣为研究材料,比较总酚、总黄酮及酚类物质的组成及抗氧化能力（DPPH自由基清除率、抗亚油酸过氧化能力和总还原力）的差异性。结果表明：1）4 个成熟期的灵武长枣总酚含量变化范围为2 996.60～5 801.84 μg/g（以没食子酸计）,总黄酮含量变化范围为33.12～122.12 μg/g（以芦丁计）,白绿期总酚和总黄酮含量最高,两者随着果实的成熟逐渐下降。2）灵武长枣中检出的酚类物质主要有根皮苷、阿魏酸、肉桂酸、柚皮素和根皮素,各含量均呈现先上升后下降趋势,微红期含量最高。3）灵武长枣抗氧化活性表现为白绿＞微红＞大半红＞全红。抗氧化能力与总黄酮、总酚含量呈显著相关性（P＜0.05）,与检测出的5 种酚类物质相关性较弱（P＞0.05）,决定其抗氧化能力的酚类物质仍有待进一步确定。白绿期灵武长枣的抗氧化活性均比其他成熟期高,因此从该时期获取天然抗氧化活性物质更为合适。     

Phenolic compounds and antioxidant activity in fruits of six Diospyros kaki genotypes

Fruits from six persimmon (Diospyros kaki) genotypes were compared for phenolic compounds and their antioxidant capacity in this study. The results showed that all fruit extracts exhibited strong antioxidant activities, which generally correlated positively with the total phenolic contents, total flavonoid contents, and total flavanol contents. High-performance liquid chromatography (HPLC) analysis revealed that gallic acid and quercetin were the major phenolic components in the fruit extracts of six D. kaki genotypes. Hierarchical cluster analysis showed that wild genotype D. kaki. var. Silvestris Makino belongs to the group with high phenolic content and strong antioxidant ability, while astringent genotypes D. kaki. cv. Xiuningbianshi and D. kaki. cv. Zhouqumomoshi are arranged in one group characterized by moderate phenolic content and antioxidant capacity, the non-astringent genotypes D. kaki. cv. Zenjimaru, D. kaki. cv. Jiro and the astringent genotype D. kaki. cv. Xingyangshuishi belongs to the third group because of their low phenolic content and weak antioxidant activity. On the basis of the results obtained, the persimmon fruit could be a potential source of natural antioxidants for food and pharmaceutical applications.     

Physicochemical,microbiological and sensory characteristics of snacks developed from broken rice grains and turmeric powder

The aim of the present study was to develop extruded snacks from broken rice grains (BRG) and turmeric powder (TP). Different levels of substitution of BRG by TP (0%, 2%, 4%, 8% and 10% w/w) were used. Snacks were processed in a single-screw extruder with three heating zones (41, 61 and 84 °C, respectively), using a helicoidal grooved extrusion sleeve, a 4 mm (diameter) matrix, 3:1 screw compression ratio, screw rotation of 3600 ×  g and a feed rate of 335 g min⁻¹. Snacks were evaluated for their physicochemical, microbiological and sensory characteristics; as well as for the chemical composition, phenolic compounds and the antioxidant capacity of the selected savoury snack formulation. The selected snack, with the physical characteristics closest to the traditional corn product, was obtained with 6% substitution of BRG by TP and was constituted by 7.76% protein, 4.78% lipid, 5.84% dietary fibre, 75.3% available carbohydrates, and 174.75 mg gallic acid equivalent per100 g and 6.52% of DPPH• scavenging capacity. The selected snack was shown to be feasible, once TP is an ingredient that aggregates sensory (colour and taste), nutritional (dietary fibres and total energy value) and functional (antioxidants) values to the BRG-based snack, being an alternative for the production of gluten-free snacks.     

Characterization of aroma-impact compounds in dry jujubes (Ziziphus jujube Mill.) by aroma extract dilution analysis (AEDA) and gas chromatography-mass spectrometer (GC-MS)

Aroma-impact compounds of dry jujubes obtained from Z. jujuba Mill. cv. “tangzao” (Y1), Z. jujuba Mill. cv. “muzao” (Y2), Z. jujuba Mill. cv. “lizao” (Y3), and Z. jujuba Mill. cv. “qingrunhongzao” (Y4) were analyzed by gas chromatography-olfactometry (GC-O). The result revealed 35, 29, 34, and 33 aroma-impact volatiles in the Y1, Y2, Y3, and Y4 samples, respectively. The compounds bearing the highest FD factor in each sample were (E)-2-hexenal, (E)-2-heptenal (FD = 256) for Y1, 2,3-butanedione, (E)-2-hexenal, 2,5-dimethylpyrazine, (E)-2-heptenal and β-damascenone (FD = 64) for Y2, 2,3-butanedione and β-damascenone (FD = 256) for Y3, and 2,5-dimethylpyrazine (FD = 256) for Y4.     

Nutritional composition of five cultivars of chinese jujube

The proximate composition of five cultivars of Chinese jujube, along with mineral, vitamin and total phenolic contents were determined. Investigations showed that Chinese jujube contained 80.86–85.63% carbohydrate, 57.61–77.93% reducing sugar, 0.57–2.79% soluble fibre, 5.24–7.18% insoluble fibre, 4.75–6.86% protein, 0.37–1.02% lipid, 17.38–22.52% moisture and 2.26–3.01% ash. The soluble sugars of Chinese jujube included fructose, glucose, rhamnose, sorbitol and sucrose. Fructose and glucose were identified as the major sugars while sorbitol was present in much lesser amounts. Potassium, phosphorus, calcium and manganese were the major mineral constituents in Chinese jujube. Iron, sodium, zinc and copper were also detected in appreciable amounts. The contents of vitamin C, thiamine and riboflavin were found to be 192–359, 0.04–0.08 and 0.05–0.09 mg/100 g, respectively. Total phenolic contents ranged from 5.18 to 8.53 mg/g. No correlation between total phenolic contents and antioxidant capacities or antioxidant capacities and vitamin C contents of Chinese jujube was found.     

The Study of Phenolic Compounds as Natural Antioxidants in Wine

Plant phenolics present in fruit and vegetables, and that are particularly rich in red wine, have received considerable attention because of their potential antioxidant activity. Human consumption of antioxidants has many alleged health benefits, including protection against cardiovascular diseases, and, most recently, cancer. Red wines contain a variety of polyphenolic antioxidants. Five samples of commercial red wines from Spain and four phenolic compounds of red wine: gallic acid, trans-resveratrol, quercetin and rutin, have been studied. The total phenolics content and the total antioxidant activity (TAA) of wines was determined. The total phenolic content, determined according to the Folin-Ciocalteu method, varied from 1800 to 2300?mg/L, expressed as gallic acid equivalents (GAE). The antioxidative effects of wine phenolics were determined using a system based on the inhibition by antioxidants of the absorbance of the radical cation. The relationship between antioxidant activity of phenolic compounds, as hydrogen donating free radical scavengers, and their chemical structures was studied. Furthermore, the total antioxidant activity of the wines investigated was well correlated with phenol content. Thus, the results confirm that red wine polyphenols are, in vitro, significant antioxidants.     

Physicochemical Characteristics,Antioxidant Activity,Organic Acid and Sugar Contents of 12 Sweet Cherry (Prunus Avium L.) Cultivars Grown in Turkey

Physical characteristics, antioxidant activity and chemical constituents of 12 cultivars (Prunus avium L.) of sweet cherry (Belge, Bing, Dalbasti, Durona di Cesena, Lambert, Merton Late, Starks Gold, Summit, Sweetheart, Van, Vista, and 0–900 Ziraat) were investigated. Significant differences (P < 0.05) were observed among tested cultivars for pH, total soluble solid, hardness, color parameters, antioxidant activities and pomological measurements (P < 0.05). The color parameters were important tools for the determination of fruit maturity and anthocyanin contents. Belge cultivar showed the highest levels of total phenolic and anthocyanin, while Starks Gold contained the lowest level of anthocyanins. The darker cultivars, measured by ABTS^+?, DPPH^? and FRAP, exhibited higher antioxidant activities than the lighter ones. Bing (42.78 g/kg) and Sweetheart (40.53 g/kg) cultivars contained higher levels of malic acid, which was the most intense organic acid in sweet cherries. Four different sugars were observed in the samples and their concentrations ordered as glucose > fructose >> sucrose > xylose. Sugar alcohol in the cherries was represented by sorbitol (more than 90%) and its concentration varied between 13.93 and 27.12 g/kg. As a result significant differences were observed among the physical properties and chemical constituents of the cherry cultivars.     

Sugars, organic acid and phenolic compounds of Ziziphus mauritiana Fruit

This study was conducted to identify soluble sugars, non-volatile acids and phenolic compounds in Ziziphus mauritiana fruit. Soluble sugars in Ziziphus mauritiana fruit were qualitatively determined by TLC. The sugars identified to be present in Ziziphus mauritiana were galactose, fructose and glucose. TLC was also used for qualitative analysis of phenolic compounds; five spots of phenolic compounds were observed. Only two of the observed spots were identified using the R_f values of the standards that were available. The two phenolic compounds identified by TLC were caffeic acid and p-coumaric acid. Phenolic compounds were also quantified using HPLC. Twelve peaks of phenolic compounds were detected. Among these, p-hydroxybenzoic acid, caffeic, ferulic acid and p-coumaric acid were the most abundant with concentrations of 365.94, 30.76, 19.64 and 19.28 mg/kg dry mass respectively, whereas vanillic acid was the least abundant with a concentration of 2.52 mg/kg. The organic acids were qualitatively analysed by PC and citric acid, malonic acid and malic acid were identified in the Ziziphus mauritiana fruit.     

Dynamic changes in phytochemical composition and antioxidant capacity in green and black mung bean (Vigna radiata) sprouts

The mung bean (Vigna radiata) sprout is a popular fresh vegetable in many parts of the world. In this study, the dynamic change of ascorbic acid, phenolic composition and antioxidant capacity were evaluated in green and black mung bean sprouts. Germination increased ascorbic acid, total phenolic content and antioxidant capacity in both mung beans. The green mung bean sprout generally had higher ascorbic acid, total phenolic content and antioxidant capacity than the black mung bean sprout. Most phenolic compounds, such as caffeic acid, catechin, ferulic acid, gallic acid and rutin, were found to gradually increase after germination. Therefore, mung bean sprouts, especially green mung bean sprout possessing high level of antioxidant phytochemicals, can be valuable functional vegetables and good sources of natural antioxidants.     

Effects of 1‐methylcyclopropene and gibberellic acid on ripening of Chinese jujube (Zizyphus jujuba M) in relation to quality

Overripening of Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage usually results in a dramatic decline in quality. The role of 1‐methylcyclopropene (1‐MCP) and gibberellic acid (GA) in fruit ripening of Chinese jujube during storage in relation to quality was investigated. Fruit ripening of jujube was significantly enhanced by ethylene, whereas rates of respiration and ethylene production of the fruit were reduced by 1‐MCP. Treatment with 1‐MCP or GA delayed the decreases in firmness and vitamin C and reduced the level of ethanol. Furthermore, the effectiveness of 1‐MCP was improved by replicate treatments during storage at 20 or 2 °C. In addition, treatment with GA + 1‐MCP resulted in additive beneficial effects on ripening inhibition of the fruit. Copyright © 2003 Society of Chemical Industry     

Antioxidant activity and polyphenol content of Turkish thyme (Thymus vulgaris) monitored by liquid chromatography and tandem mass spectrometry

Like tea, the leaves of Turkish thyme (Thymus vulgaris) can be boiled in water to produce an extract. This is widely used as syrup for the treatment of coughs and bronchitis at alternative medicine clinics in many parts of the world. In the current study, we assessed the phenolic content and antioxidant activity of thyme. The antioxidant activities of both ethanol and aqueous extracts of thyme were determined using various in vitro methods. The total phenolic and total flavonoid contents were determined to be a gallic acid equivalent and a quercetin equivalent, respectively. Finally, the quantities of the phenolic compounds were detected using high-performance liquid chromatography and tandem mass spectrometry. The total phenolic compounds in the aqueous extract and ethanol extracts of Turkish thyme were 256.0 μg gallic acid equivalent/mg dried extract and 158.0 μg gallic acid equivalent/mg dried extract, respectively. Conversely, the total flavonoid compounds in both extracts were 44.2 μg and 36.6 μg quercetin equivalent/mg dried extract, respectively. For the first time, we determined phenolic contents and investigated the antioxidant potential of thyme. The results indicate that Turkish thyme is a good dietary source with phenolic properties.     

Antioxidant activity and phenolic compounds of Swiss chard (Beta vulgaris subspecies cycla) extracts

The antioxidant activity (radical scavenging and thiocyanate method), total phenolic contents (gallic acid equivalents) and phenolic composition (coulometric array detection) in methanol extracts of different parts and tissue types of hydroponically grown Swiss chard (Beta vulgaris subspecies cycla) were determined. Significant differences (P <0.01) in the antioxidant activity were found between leaves and stems. Phenolic content and composition of the leaves and the stems also were found to be different. A positive linear correlation (R=0.943) was demonstrated between radical scavenging activity and total phenolic content of each extract. The major phenolic acid and flavonoid in leaves of Swiss chard were syringic acid and kaempferol. Coulometric array detection showed good reproducibility (CV, 0.06–1.05%) and sensitivity (1 ng/ml, detection limit) for simultaneous detection of 13 phenolics. Our data indicates that Swiss chard has potential as a good dietary source of phenolic antioxidants.     

红枣膳食纤维酶法提取工艺优化及其抗氧化研究

以新疆红枣为研究对象,通过单因素试验及响应面试验优化红枣膳食纤维酶法提取工艺,并对其理化性质及抗氧化特性进行测定和评价。结果发现,当酶添加量为1.5 mg·mL-1,酶解温度为50℃,液料比为9:1 mL/g,酶解时间为45 min时,红枣膳食纤维酶法提取率最高,达到9.18%,与预测值误差仅为0.33%。酶法提取与热水浸提相比,其持水力、持油力、膨胀力、阳离子交换能力等指标均有不同程度的提升,且均存在显著性差异(P<0.05)。抗氧化性研究结果显示,红枣膳食纤维对DPPH·有较强的清除能力,IC₅₀为0.227 mg·mL-1,显示了其较高的体外抗氧化活性,可以作为天然抗氧化剂进行开发。     

Changes in the contents of antioxidant compounds in pepper fruits at different ripening stages,as affected by salinity

The interest in the consumption of pepper fruits (Capsicum annuum L.) is, to a large extent, due to its content of bioactive nutrients and their importance as dietary antioxidants. A greenhouse experiment was carried out to determine the effects of salinity and different ripening states of pepper fruits on several compounds with antioxidant properties. Fruits from plants grown under three saline treatments (0, 15, and 30 mM NaCl) were collected at three maturity states (green, turning, and red). Antioxidant activity in the hydrophilic (HAA) and lipophilic (LAA) fractions, lycopene, β-carotene, ascorbic acid, total phenolic compounds and reducing sugars were determined. From the nutritional point of view, the red state was the most appropriate state of maturation, since red peppers had the highest levels of lycopene, β-carotene, and sugars and the highest antioxidant activity for both hydrophilic and lipophilic fractions. The effect of salinity depended on the maturity state of the peppers: it had no effect on HAA, β-carotene or sugars, but decreased ascorbic acid and total phenolic compounds, and increased LAA and lycopene. The use of a moderately-saline water was beneficial when peppers were harvested in the red state, by increasing HAA and LAA in fruits, with no significant effects on other parameters.