Phytochemical Content,Antioxidant Properties,and Phenolic Profile of Tunisian Raisin Varieties (Vitis Vinifera L.)

Four raisin (Vitis vinifera L.) varieties, Chriha, Razeki, Assli, and Meski, were evaluated for total phenolic content, total o-diphenol content, total flavonoid content, total condensed tannin, total carotenoid content, and total anthocyanin content. Antioxidant potential was assessed by three assays: 2,2-Diphenyl-1-Picrylhydrazyl and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical scavenging capacity and ferric reducing power. Individual phenolic profiles were determined by high-performance liquid chromatography. The results revealed that the four raisin varieties had considerable phenolic content and antioxidant activity. Chriha had the highest total phenolic content (534.2 mg/g dry weight) while Meski had high total condensed tannin (208.6 mg CEQ/g dry weight), TAC (137 mg/100 g dry weight), total o-diphenol content (115.8 mg/g dry weight), total flavonoid content (93 mg CEQ/g dry weight), and total carotenoid content (33 mg/100 g dry weight). There were significant differences in phenolic content among the four varieties (p < 0.05). Meski had the highest 2,2-Diphenyl-1-Picrylhydrazyl scavenging capacity, while Chriha had adequate reducing power and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid scavenging capacity. The individual phenolic compounds (2.96–6.54 mg/g dry weight) were variety-dependent.     

Level of Vitamin C,Polyphenols, and Antioxidant and Enzymatic Activity in Three Varieties of Kale (Brassica Oleracea L. Var. Acephala) at Different Stages of Maturity

The aim of this present study was to determine the level of vitamin C, L-ascorbic acid, polyphenols, antioxidant activity, peroxidase, polyphenol oxidase, and catalase in the leaves of three varieties of kale at different stages of maturity. Average values per 100 g of fresh matter were 102 mg of vitamin C (of which L-ascorbic acid constituted 97%) and 359 mg polyphenols; antioxidant activity was measured at 48.9% RSA (17.6 μM Trolox/g kale). Redbor₁ c.v. variety contained the highest levels of the analyzed constituents. Compared with the first stage of maturity, plants at the second stage showed increases of 6% in vitamin C; 28% in polyphenols; and 12% in antioxidant activity, whereas plants at the third stage showed 5, 48, and 22% increased values, respectively. Average POD activity was 7.58 ΔA/min/g, PPO 1.64 ΔA/min/g, and CAT 7.93 mg H₂O₂/min/g. PPO activity increased with the age of the plant. No consistent correlation was found between the stage of growth and the other enzymes.     

不同品种和成熟度树莓和黑莓果实的氧化和抗氧化活性比较

采用多变量分析方法探讨不同品种和成熟度对树莓和黑莓果实氧化和抗氧化活性的影响。单因素方差分析表明,“三冠王”黑莓果实的谷胱甘肽(GSH)、总酚和总黄酮含量均显著高于其他品种,且随果实成熟度的升高,总抗氧化能力下降。品种和成熟度对树莓和黑莓果实的GSH、总酚和丙二醛(MDA)含量,以及清除羟自由基( ·OH)能力的影响更为显著。主成分分析表明,相比于成熟度而言,品种对树莓的抗氧化能力影响更为显著。相关性分析和偏最小二乘回归分析表明,过氧化氢与MDA、GSH和清除超氧阴离子自由基(O2－ ·)均呈正相关性,而总酚与总抗氧化能力、清除 ·OH能力、清除DPPH自由基能力呈正相关性;通径分析表明,树莓和黑莓果实的总酚含量和总黄酮对H2O2含量的直接效应最强。     

Antioxidant compounds and antioxidant capacity of Peruvian camu camu (Myrciaria dubia (H.B.K.) McVaugh) fruit at different maturity stages

The antioxidant capacities of ascorbic acid and phenolic compounds present in camu camu fruit were screened during ripening. Ascorbic acid decreased, and anthocyanin, flavonol and flavanol contents, and DPPH antioxidant capacity increased during ripening. Antioxidant compounds from camu camu were fractionated in two fractions: an ascorbic acid-rich fraction (F-I) and a phenolics-rich fraction (F-II). F-I was the major contributor to the DPPH antioxidant capacity (67.5–79.3%) and F-II played a minor role (20.7–32.5%). A total of 30 different phenolic compounds were detected by HPLC-PAD. The presence of catechin, delphinidin 3-glucoside, cyanidin 3-glucoside, ellagic acid and rutin was elucidated. Other phenolic compounds, such as flavan-3-ol, flavonol, flavanone and ellagic acid derivatives, were also present. For the three ripening stages the flavan-3-ols and ellagic acid group were the most representative phenolic compounds in this fruit. Acid hydrolysis of F-II revealed the presence mainly of gallic and ellagic acids, suggesting that camu camu fruit possesses important quantities of hydrolysed tannins (gallo- and/or ellagitannins). These results confirm that camu camu fruit is a promising source of antioxidant phenolics.     

不同煎炸阶段薯条和煎炸油中关键风味成分分析（网络首发、推荐阅读）

风味是薯条受欢迎程度的决定性感官特征。煎炸油一旦加热,油脂的变化会直接影响食物的风味。在高油酸菜籽油(RO)煎炸过程中,煎炸薯条(FF)的风味发展表现出三个明显的阶段,包括诱导阶段(总极性化合物(TPC)的含量为3.0%~8.0%)、最佳阶段(TPC的含量为8.0%~20%)和降解阶段(TPC的含量为22%以上)。为了区分各阶段的关键香气化合物,选择了极性化合物为3.0%(FF1)、10.5%(FF2)和27%(FF3)的高油酸菜籽油制备的薯条及其相关油(RO1、RO2、RO3)进行感官分析。结果表明,FF1中,(E,E)-2,4-癸二醛(油炸气味)含量较低,这可能是FF1样品感官评分较低的原因。与FF1和FF2相比,FF3具有较高的己酸(汗臭味)、庚酸、壬酸、苯乙醛和反式-4,5-环氧-(E)-2-癸烯醛(金属气味),导致FF3的风味恶化。此外,FF3中2,5-二甲基吡嗪和2-乙基-6-甲基-吡嗪的减少导致了较低的烘焙风味,可能使得感官评分下降。同样,RO3中(E)-2-十一烯醛、己酸、庚酸和壬酸含量较高,其酸败评分增加,从而降低感官评分。当TPC含量超过22%时,油的过氧化作用会引起酸败味,因此煎炸后期应加以控制,通过研究煎炸过程中关键风味物质的变化,对开发具有最佳风味的油炸产品有借鉴意义。     

Physicochemical Properties of Starch in Sago Palms (Metroxylon sagu) at Different Growth Stages

This study was aimed to examine the physicochemical properties of starch extracted from two different points (base and mid heights) of the sago palms trunks (Metroxylon sagu) of different physiological growth stages namely, ‘Plawei’, ‘Bubul’, ‘Angau Muda’, ‘Angau Tua’ and ‘Late Angau Tua’ stages. The physicochemical properties of sago starch studied were the morphology of starch, amylose content, particle size and distribution profile, pasting, thermal and retrogradation profiles. The results showed significant differences in the amylose and amylopectin content as well as in the granule sizes of starch from the different growth stages. Variation was observed in the proportions of granule sizes and pasting properties of starch from base and mid heights of the different growth stages while slight or insignificant differences was observed in the thermal properties of sago starch.     

不同成熟度香菇鲜味物质的比较分析

为了确定新鲜香菇子实体的最佳采收期,对不同成熟度香菇子实体中的鲜味物质（氨基酸和5’-核苷酸）进行了检测,并采用主成分分析和层次聚类分析的方法对数据进行了统计分析。结果表明,成熟度对新鲜香菇子实体中的氨基酸和5’-核苷酸有显著影响,不同成熟度香菇样本间存在显著差异。主成分分析（PCA）结合氨基酸和5’-核苷酸数据能够对不同成熟度的香菇样本进行清晰的区分,聚类分析（欧氏距离为4.0）得到的结果与主成分分析结果一致。新鲜香菇子实体氨基酸和5’-核苷酸质量分数、等效鲜味浓度（EUC）、感官评价和综合评价得分在菇蕾（T1）时期达到峰值,常规采摘期即六成熟（T4）和八成熟（T5）时期居中。在本实验条件下,综合考虑,保证香菇的外观形态、经济效益、EUC、感官评价和综合评价得分均在较高水平的最佳采收时间为T4时期。本研究可为高品质香菇及其他类似农产品最佳采收期的确定提供参考。     

不同时期梨枣叶茶抗氧化成分组成及活性差异的分析

目的:探讨不同采收时期梨枣叶茶抗氧化成分的含量、组成及其活性的差异,揭示梨枣叶茶抗氧化功能品质随采收时期的变化规律。方法:以陕北地区5—8月份矮化密植枣园生长的梨枣嫩叶制成的梨枣叶茶为研究材料,比较总酚、黄酮和VC含量及酚类物质的组成及抗氧化能力(总还原力、DPPH自由基清除率和ABTS+.清除率)的差异性。结果:7月、8月加工的梨枣叶茶抗氧化物质含量及抗氧化能力高于5月和6月加工的梨枣叶茶。梨枣叶茶的酚类和黄酮类物质以及VC含量在不同时期呈现出显著性差异(P<0.05),其中总酚含量变化范围为(29.94±0.28)～(42.65±0.56)mg/g(以没食子酸计),黄酮含量变化范围为(16.61±0.39)～(25.21±1.53)mg/g(以芦丁计),VC含量变化范围为136.5～324.6mg/100g。梨枣叶茶检出的酚类物质主要为没食子酸、儿茶素、芦丁和槲皮素,它们的含量在不同时期也存在显著性差异(P<0.05),其中芦丁是含量最高的酚类物质,最高含量达到60.11mg/100g。梨枣叶茶抗氧化能力与总酚和黄酮含量分别呈现显著(P<0.05)和极显著(P<0.01)相关性,与VC含量相关性不大。结论:夏季采收的梨枣叶茶抗氧化活性强,芦丁是构成梨枣叶茶酚类物质最主要的成分。     

In Vitro Antioxidant and Antiglycation Properties of Methanol Extract and Its Different Solvent Fractions of Musa paradisiaca L. (Cv. Nendran) Inflorescence

Methanolic extract of Musa paradisiaca inflorescence and its different solvent fractions, petroleum ether, ethyl acetate, butanol, and water were studied for their total phenolic and flavonoid content, free radical scavenging, and antiglycation activities, and these properties were compared with standard antioxidant compounds. Ethyl acetate fraction exhibited higher antioxidant and antiglycation properties than other fractions. IC₅₀ values of ethyl acetate fraction for 1,1-diphenyl-2-picrylhydrazyl method, 2,2-azinobis-3 ethylbenzothiazoline-6-sulphonic acid method, superoxide radical scavenging, hydroxyl radical scavenging, nitric oxide radical scavenging, and antiglycation activities were 9.80, 13.50, 26.40, 19.71, 25.73, and 31.00 μ g/ml, respectively. Total phenolic content of ethyl acetate (21.52 mg GAE/g) was significantly higher than other fractions. There was positive linear correlation between antioxidant activity and total phenolic content.      

Effect of Maturity Stages and Drying Methods on the Retention of Selected Nutrients and Phytochemicals in Bitter Melon (Momordica charantia) Leaf

ABSTRACT:  The purpose of this study was to investigate the nutrient and phytochemical composition of bitter melon leaves under varying maturity levels and drying techniques. Fresh, oven-dried, and freeze-dried leaves were evaluated over 3 maturity stages. In fresh leaves at various stages, crude fat, crude protein, and soluble dietary fiber contents ranged from 4.2% to 13.6%, 6.4% to 23.1%, and 0.04% to 3.50% on dry-weight basis, respectively. The contents of K, Ca, Mg, Fe, and Zn ranged from 1850.8 to 2811.8, 837.4 to 4978.2, 317.3 to 512.4, 8.4 to 16.7, and 4.1 to 5.9 mg/100 g dry-weight basis, respectively. Vitamin C, β-carotene, and lutein contents ranged from 397.4 to 1275.1, 154.2 to 422.8, and 737.6 to 1304.6 μg/g dry-weight basis. The major flavonoids and phenolic acids were rutin, gentistic acid, and  o -coumaric acid, which ranged from 7.57 to 12.75, 2.53 to 10.11, and 4.24 to 9.75 mg/g dry-weight basis, respectively. In oven-dried samples, 40.2% to 52.3% of vitamin C, 35.4% to 55.4% of β-carotene, 25.6% to 71.6% of lutein, 26.4% to 84.0% of rutin, trace to 11.4% of gentistic acid, and 7.4% to 46.6% of  o -coumaric acid were retained, while the retainment ratios of these components in freeze-dried samples were 84.7% to 99.0%, 76.4% to 99.3%, 90.4% to 96.1%, 39.8% to 99.3%, 24.1% to 68.4%, and 75.8% to 87.0%, respectively. The data showed that freeze-drying better preserves the nutrient and phytochemical quality of bitter melon leaves in comparison to oven-drying. Bitter melon leaf is a rich source of selected nutrients and phytochemicals.     

Phytochemical and antioxidant characterization of mamey (Pouteria sapota Jacq. H.E. Moore & Stearn) fruit

Phytochemical compounds in fruits and vegetables have gained great importance in the last few years because of the increasing evidence suggesting their antioxidant and prevention of chronic diseases. Carotenoids, phenolics, flavonoids, and vitamins E and C, are among these phytochemicals. Several fruits have been characterized so far for their antioxidant and health properties but there is still limited information on fruits from the tropic. Therefore, the objective of this study was the characterization of mamey fruit (Pouteria sapota Jacq. H. E. Moore & Stearn) with regard to their antioxidant capacity and phytochemical profile. Phenolics, carotenoids and ??-tocopherol were quantified and identified by HPLC-DAD-Mass Spectrometry (LC-MS), and DPPH and FRAP assays were used to evaluate antioxidant capacity. Hydrophilic extracts of mamey fruit showed higher antioxidant capacity than the lipophilic portion. Total soluble phenols content was 28.5 mg GAE/100 g fw, being p-hydroxybenzoic acid as the main phenolic that was identified. Total carotenoid content was 1127.9 ??g ??-carotene/100 g fw with ??-carotene being the main contributor, in addition to lutein, and violoxanthin. Concentration of ??-tocopherol was 360.0 ??g/100 g fw. Results of this study suggest that mamey fruit is a good source of carotenoids and its inclusion in the diet is recommended.     

Variation in antioxidant enzyme activities and nonenzyme components among cultivars of rabbiteye blueberries (Vaccinium ashei Reade) and V. ashei derivatives

Fruit from 42 blueberry (Vaccinium species) cultivars, including 36 rabbiteye cultivars (Vaccinium ashei Reade), 3 V. ashei hybrid derivatives and 3 northern highbush (V. corymbosum L.) standards, were evaluated for antioxidant activities (AA), levels of antioxidant enzymes [catalase (CAT), ascorbate peroxidase (AsA-POD), glutathione reductase (GR), glutathione peroxidase (GSH-POD), superoxide dismutase (SOD), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDAR) and guaiacol peroxidase (G-POD)], and antioxidant nonenzyme components [ascorbic acid (ASA) and glutathione (GSH)]. The results of this study showed that cultivars had varying levels of AA, a wide range of antioxidant enzyme activities and various amounts of nonenzyme components. The correlations between AA and all of the enzyme activities or nonenzyme components were positive and high in the 42 cultivars tested in this study. The correlation (R²) values between AA and CAT, SOD, DHAR, MDAR, GSH-POD, GR, G-POD and AsA-POD were 0.91, 0.91, 0.91, 0.91, 0.90, 0.90, 0.90, and 0.90, respectively. The correlations between AA and ASA and GSH were 0.94 and 0.92, respectively. Among all 42 cultivars, ‘Early May’ had the highest activities of the AA, AsA-POD, G-POD, DHAR and MDAR and the highest amounts of ASA and GSH, whereas ‘Elliott’ had the highest levels of GR, GSH and SOD.     

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。     

Effect of defatting and decortication on distribution of fatty acids,phenolic and antioxidant compounds in sorghum (Sorghum bicolor) bran fractions

Sorghum bran components could be a potential source of nutrients and phytochemicals for industrial applications. The effect of defatting with hexane and different degrees of decortication on distribution of fatty acids, phenolic compounds, colour (L, a and b) and antioxidant activity (DPPH) of red (RS) and white (WS) sorghums was studied. The decortication process was carried out at time intervals of 1–6 min. Defatted and nondefatted fractions were analysed. The content of polyunsaturated fatty acids (PUFA) was higher than monounsaturated fatty acids (MUFA); the content of MUFA was higher than saturated fatty acids (SFA). Linoleic, oleic and palmitic acids predominated in all fractions. Significant differences in the content of palmitic and linolenic acids between sorghums were found. RS had higher content of palmitic, and WS was higher in linoleic acid. Defatted samples contained lower amounts of phenolic compounds and higher antioxidant activities, than nondefatted samples. RS was a better source of total phenolic compounds and antioxidant activity compared with WS, but WS presented a more suitable profile of fatty acids. In conclusion, fractions of both types of sorghums can be used in cereal‐based products to enhance their phytochemical profile.     

Bioactive and Antioxidant Activity from Citrus bergamia Risso (Bergamot) Juice Collected in Different Areas of Reggio Calabria Province,Italy

The chemical composition and antioxidant activity of juice extracted from seven samples of bergamot (Citrus bergamia Risso) collected in different areas of Reggio Calabria Province were investigated. The ascorbic acid, total polyphenol, and flavonoid contents were determined. Total flavonoids and polyphenols were analyzed by ultraviolet spectra, while flavanone content was analyzed by high-performance liquid chromatography. The antioxidant activity of the fractions was assessed using three representative assays: 2,2′-azinobis(3-ethylbenzothiazoline 6-sulfonic acid), 1,1-Diphenyl-2-picryl-hydrazyl radical quenching and β-carotene bleaching test. The main flavanones were naringin, neohesperedin, and neoeriocitrin, and their average content 242.4 ± 1.8, 183.0 ± 0.6, and 247.0 ± 1.4 mg mL^–1, respectively. The results showed that bergamot juice possessed a good quality and a valuable source of health promoting constituents. In fact it contained eriocitrin, naringin, neoeriocitrin, and neohesperedin, which may contribute differentially to the antioxidant capacity.     

金丝小枣在生长成熟过程中理化特性的变化规律

本文研究了6个不同生长成熟期(S1~S6)金丝小枣果实的色泽、叶绿素、可溶性糖及其代谢酶活性、有机酸及氨基酸的动态变化,以明确其代谢规律。研究结果表明:枣果生长成熟过程中,叶绿素含量降低,枣果由绿变红;葡萄糖、果糖均逐步积累,而山梨醇含量逐渐降低,蔗糖则在生长发育初期未被检出,其积累主要发生在枣果成熟后期,且其含量最高,金丝小枣为蔗糖积累型果实,蔗糖磷酸合成酶是蔗糖积累的关键酶;金丝小枣为苹果酸型果实,苹果酸随枣果的成熟而积累,而柠檬酸含量先上升后降低;Pro和Asp在枣果成熟过程中被大量合成,是成熟枣果中最主要的两种氨基酸。全红枣的可溶性总糖、糖酸比以及游离氨基酸总量最高,可作为金丝小枣鲜食的最佳采收时期。     

Physicochemical and bioactive compounds at edible ripeness of eleven varieties of avocado (Persea americana) cultivated in the Andean Region of Peru

This work aimed evaluating some physicochemical compounds, hydrophilic (H-AC) and lipophilic (L-AC) antioxidant capacity of eleven avocado genotypes grown in the Andes. The results show great variability in physical and chemical properties, dry matter (DM) and lipid contents with ranges of 18.4–39.3% and 10.1–23.2%, respectively. All genotypes had high oleic acid content (50.4–69.9%) and a high unsaturated fatty acid/saturated fatty acid ratio (UFA/SFA, from 3.05 to 6.05), while the unsaponifiable fraction contained mainly β-sitosterol (140.83–235.51 mg/100 g DM) and α-tocopherol (17.44–71.29 µg/g DM). Total phenolic compounds (TPC), H-AC and L-AC ranged from 0.48 to 0.88 mg EAG/g DM, 5.37 to 14.00 and 1.87 to 6.71 μmol ET/g DM, respectively. Although the genotype influences avocado characteristics, climatic conditions in the Andean region seem to be important for the biosynthesis of metabolites of interest and should be considered in future studies.     

Antioxidant activity and total phenolic content of Agaricus brasiliensis (Agaricus blazei Murril) in two stages of maturity

The antioxidant capability and total phenolic contents of methanolic extracts of Agaricusbrasiliensis in two stages of maturity, young (YB) and mature (MB), were evaluated in this work. Four complementary assays, reducing power, radical scavenging capacity, inhibition of lipid peroxidation and chelating ability for ferrous ions were used to screen the antioxidant properties of extracts. Minor differences in the composition of phenolic compounds were detected, but the extracts showed similar antioxidant activities, except for the chelating ability for ferrous ions, higher in MB than in YB. Our results support the use of both young and mature fruiting bodies of Agaricus blazei as sources of antioxidant compounds.