Storage Induced Changes of Phenolic Acids and the Development of Hard-To-Cook in Dry Beans (Phaseolus vulgaris var. Seafarer)

Navy beans were stored for 9 months under three conditions (5°C/ 40% RH, 20°C/73% RH, and 35°C/80% RH) to produce different degrees of hard-to-cook (HTC) defect. Changes in free hydroxycinnamic acids, hexane soluble and methanol soluble hydroxycinnamic acids, cell wall bound hydroxycinnamic acids, and lignin content were determined. Storage induced HTC beans contained higher levels of hydroxycinnamic acids (especially ferulic acid) than the control beans in all fractions prepared from seed coats and cotyledons except for the methanol soluble and cell wall bound phenolic acid fractions from cotyledons. No significant changes in lignin content were detected among the treatments. Large increases in free hydroxycinnamic acid content associated with increased hardening, suggest a relationship between these two factors.     

Characterisation of calamansi (Citrus microcarpa). Part I: Volatiles,aromatic profiles and phenolic acids in the peel

Volatile compounds in the peel of calamansi (Citrus microcarpa) from Malaysia, the Philippines and Vietnam were extracted with dichloromethane and hexane, and then analysed by gas chromatography–mass spectroscopy/flame ionisation detector. Seventy-nine compounds representing >98% of the volatiles were identified. Across the three geographical sources, a relatively small proportion of potent oxygenated compounds was significantly different, exemplified by the highest amount of methyl N-methylanthranilate in Malaysian calamansi peel. Principal component analysis and canonical discriminant analysis were applied to interpret the complex volatile compounds in the calamansi peel extracts, and to verify the discrimination among the different origins. In addition, four common hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) were determined in the methanolic extracts of calamansi peel using ultra-fast liquid chromatography coupled to photodiode array detector. The Philippines calamansi peel contained the highest amount of total phenolic acids. In addition, p-Coumaric acid was the dominant free phenolic acids, whereas ferulic acid was the main bound phenolic acid.     

椪柑、温州蜜桔果皮中酚类物质组成及抗氧化能力研究

目的:研究椪柑、温州蜜桔果皮中酚酸与黄烷酮糖苷组成及其抗氧化能力。方法:高效液相法测定椪柑、温州蜜桔果皮中九种酚酸和两种黄烷酮糖苷的组成与含量。用福林酚法、ABTS法和FRAP法对椪柑、温州蜜桔果皮甲醇提取液抗氧化能力进行评价。结果:柑橘果皮中可溶酯化酚酸部分所占比例最大,肉桂酸型酚酸是柑橘皮中的主要酚酸,且主要以酯化形式存在,其含量排列顺序一般为:阿魏酸>对香豆酸>芥子酸>咖啡酸。温州蜜桔果皮中有较高总酚酸含量(p<0.05)。椪柑果皮主要含橙皮苷,温州蜜桔果皮含橙皮苷和少量柚皮芸香苷。温州蜜桔果皮中总黄烷酮糖苷含量高于椪柑(p<0.05)。总的来说椪柑果皮提取液抗氧化活性略高于温州蜜桔。结论:HPLC测定柑橘皮中酚酸与黄烷酮糖苷可取得良好结果,抗氧化实验表明柑橘皮具有一定的抗氧化能力。     

Four phenolic acids from purple sweet potato and their effects on physicochemical,digestive and structural characteristics of starch

Liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) was employed to investigate free phenols that were released from purple sweet potato (PSP) by alkaline, acid and enzymatic hydrolysis. Four phenolic acids, including ferulic, isoferulic, 4-hydroxybenzoic and caffeic acids, were identified. Based on their effects on the characteristics of purple sweet potato starch (PSPS), the four phenolic acids were studied. Furthermore, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT–IR) and X-ray diffraction (XRD) techniques were employed to explore the microstructures of the complexes of the phenolic acids and PSPS. The obtained results demonstrated that the pasting, thermal, retrogradation, as well as digestive properties of PSPS were all influenced by the phenolic acids which interacted with PSPS through noncovalent hydrogen bonds. The influence of the four phenolic acids on the properties of PSPS was in the descending order: 4-hydroxybenzoic acid > ferulic acid > caffeic acid > isoferulic acid.     

Effect of thermal sterilization on ferulic, coumaric and cinnamic acids: dimerization and antioxidant activity

BACKGROUND: Some phenolic compounds, such as ferulic acid and p‐coumaric acid, exist in the form of free acids, in fruits, rice, corn and other grains. Thermal treatment (121 °C at 15–17 psi) for different times on ferulic, p‐coumaric and cinnamic acids as well as equimolar mixtures of these acids was investigated. RESULTS: Ferulic and p‐coumaric acids underwent decarboxylation, yielding dimeric products formed through their corresponding radical intermediates, while cinnamic acid was recovered unreacted. High‐performance liquid chromatography analysis showed no cross‐dimerization when equimolar mixtures of pairs of hydroxycinnamic acids were treated under the same conditions. Dimers were characterized as (E)‐4′,4″‐(but‐1‐ene‐1,3‐diyl)bis(2′‐methoxyphenol)) (dimer of 4‐vinylguaiacol) and (E)‐4,4′‐(but‐1‐ene‐1,3‐diyl)diphenol) (dimer of 4‐vinylphenol) by nuclear magnetic resonance and mass spectrometry. CONCLUSION: Sterilization by thermal processing produced dimers of ferulic and coumaric acid. The antioxidant activity of these dimers was greater than that of the respective hydroxycinnamic acids. These results may be relevant for fruits and grains that contain hydroxycinnamic acids and undergo sterilization processes such as canning. Copyright © 2012 Society of Chemical Industry     

不同成熟期蜜桔中酚酸的组成与分布

酚酸具有多种生理功能,在植物中广泛存在.柑橘可能是膳食酚酸的重要来源.采用HPLC-PDA测定了不同成熟期温州蜜桔中八种酚酸的含量,即绿原酸、咖啡酸、对香豆酸、阿魏酸、芥子酸、原儿茶酸、对羟基苯甲酸和香草酸.结果显示,果肉中酚酸含量随成熟度提高而减少,果皮酚酸含量在半成熟期最高;果皮中酚酸含量大大高于果肉;果皮果肉中都以肉桂酸型酚酸为主,苯甲酸型酚酸含量较少;蜜桔果实中绿原酸和阿魏酸是所测八种酚酸中含量最高的.对柑橘中酚酸组成与分布的研究可望应用于食品营养标识、柑橘品种的识别或加工果汗掺假的识别等.     

A comparative study on free and bound phenolic acid content and their antioxidant activity in bran of rice (Oryza sativa L.) cultivars of Eastern Himalayan range

In our study, seven most prevailing but unexplored indigenous rice cultivars of northeast India, situated in the Eastern Himalayan Range, were investigated for their phenolic acid profile, total phenolic content (TPC) and antioxidant capacities in free and bound phenolic extracts of their bran. HPLC studies showed the presence of ferulic, p‐coumaric, sinapic, caffeic, chlorogenic and vanillic acids, with ferulic and p‐coumaric acids being the dominant phenolic acids in the bound form. The lower EC₅₀ values of the bound extracts than the free extracts suggested the better radical scavenging activity of the bound extracts. Significant correlations were observed between TPC and phenolic acid content (HPLC‐DAD) of bound extracts, and between Trolox equivalents antioxidant capacity (TEAC) and phenolic acid content (HPLC‐DAD) of both free and bound extracts. The findings suggest that phenolic acids in the rice cultivars investigated were exclusively present in bound form and contribute significantly towards their antioxidant capacity.     

小麦麸皮中酚酸提取方法的研究

研究了酸种类、酸碱浓度、水解时间、水解顺序对小麦麸皮中束缚型酚酸释放量的影响。结果表明,酚酸在小麦麸皮中主要以束缚型形式存在,且肉桂酸类酚酸含量明显高于苯甲酸类酚酸,其中以阿魏酸的含量最高。水解方法对酚酸释放量的影响存在显著差异。采用超声波辅助有机溶剂（甲醇：丙酮：水=7：7：6）提取,酚酸释放量最高的水解条件为：先用2mol／L氢氧化钠室温水解4h,再用2mol／L盐酸于85℃下水解1h,束缚型酚酸总释放量达4719μg／g麸皮。     

甘蔗不同组织中游离态和结合态酚酸的分布及抗氧化活性

为了探讨甘蔗不同组织中酚酸的存在形式,本文利用反相高效液相色谱法(RP-HPLC)对蔗汁、蔗叶及蔗渣三个组织中游离态和结合态的酚酸进行了定性和定量检测分析。结果表明,甘蔗组织中的酚酸主要以结合态形式存在,但其在甘蔗三个组织中的含量和存在形式有差别。甘蔗叶、蔗渣中游离的酚酸含量最高,蔗汁较低。蔗汁、蔗叶及蔗渣中总游离态酚酸含量分别为317.18 mg/kg(干固物),1568.37 mg/kg(干基)及1504.57 mg/kg(干基);总结合态酚酸含量分别为740.32 mg/kg(干固物),2725.41 mg/kg(干基),2452.13 mg/kg(干基)。在蔗汁中,咖啡酸、没食子酸主要以游离态存在,阿魏酸、香豆酸主要以结合态存在,而在蔗叶和蔗渣中,咖啡酸、阿魏酸、香豆酸主要以结合态形式存在。甘蔗不同组织中游离态酚酸的DPPH和ABTS自由基清除活性优于结合态酚酸,不同组织中的游离态酚酸和结合态酚酸含量分别与抗氧化活性呈正相关性。     

Phenolic compounds,lycopene and antioxidant activity in commercial varieties of tomato (Lycopersicum esculentum)

Nine commercial varieties of tomato (Rambo, Senior, Ramillete, Liso, Pera, Canario, Durina, Daniella and Remate) produced in Spain were analysed for their lycopene content, content of phenolic compounds and antioxidant capacity. The phenolic compounds were characterised as flavonoids (quercetin, kaempferol and naringenin) and hydroxycinnamic acids (caffeic, chlorogenic, ferulic and p‐coumaric acids). Antioxidant activity was measured using the DPPH and ABTS assays. The concentrations of lycopene and the various phenolic compounds as well as the antioxidant activity were significantly influenced by the tomato variety. Quercetin, the most abundant flavonoid, was found in concentrations ranging between 7.19 and 43.59 mg kg^?1 fresh weight, while naringenin levels were lower than 12.55 mg kg^?1. The most abundant hydroxycinnamic acid was chlorogenic acid, with values ranging from 14 to 32 mg kg^?1 fresh weight, followed by caffeic acid, while p‐coumaric and ferulic acids showed similar concentrations lower than 5 mg kg^?1. The highest content of lycopene was found in Ramillete, Pera and Durina (>50 mg kg^?1 fresh weight), while the concentration in the other varieties was between 50 and 30 mg kg^?1, with the exception of Liso (less than 20 mg kg^?1). The antioxidant activity of tomato extracts varied with the tomato variety and the assay method used. Individual compounds found to be significantly related to antioxidant capacity were lycopene and ferulic and caffeic acids, but not quercetin and chlorogenic acid. © 2002 Society of Chemical Industry     

Phenolic compounds in peanut seeds: Enhanced elicitation by chitosan and effects on growth and aflatoxin B1 production by Aspergillus flavus

Effects of chitosan and Aspergillus flavus to enhance elicitation of phenolic compounds in viable peanut seeds were conducted at two water activity levels. In vitro effects of phenolic acids on A. flavus growth and aflatoxin B₁ production were also studied. Chitosan enhanced elicitation of free phenolic compounds (FPC) at Aw .85 and .95 levels. A. flavus initially decreased and subsequently increased FPC content, but bound phenolic compounds (BPC) decreased during incubation. Chitosan + A. flavus treatment caused an increase in FPC reaching a plateau between 24–48 h at Aw .85 while BPC levels increased over the same period at both Aw levels. Major free and bound phenolic acids detected were p‐coumaric, ferulic and an unknown phenolic acid eluting at a retention time of 22 min. Generally, chitosan significantly enhanced elicitation of free ferulic and p‐coumaric acids and bound p‐coumaric acid at Aw .95. Free unknown phenolic and bound ferulic acids at Aw .85 were enhanced by chitosan. A. flavus caused significant induction of bound p‐coumaric and ferulic acids and free unknown phenol at Aw .85. Chitosan + A. flavus enhanced free p‐coumaric (3 h) and unknown phenolic acids and bound p‐coumaric acid at Aw .95 while bound ferulic acid was enhanced at Aw .85. Chitosan limited A. flavus growth and subsequent aflatoxin production by inducing susceptible tissues to produce more preformed phenolic compounds.

Analysis of liquid cultures of A. flavus revealed that p‐coumaric, ferulic, and vanillic acids and a mixture of these phenolic acids slightly inhibited mycelial growth. Production of aflatoxin B₁ by A. flavus was completely inhibited at 1 mM and 10 mM concentrations of the phenolic acids and their mixture on four days of incubation. Mode of action of phenolic acids is likely on the secondary pathway for aflatoxin B₁ production and not on the primary metabolism for fungal growth.     

Determination of Phenolic Compounds in Strawberries (Fragaria ananassa Duch) by High Performance Liquid Chromatography with Diode Array Detection

This paper describes a method for simultaneous identification and quantification of phenolic compounds in strawberries followed by a reversed-phase high performance liquid chromatography (HPLC) with diode array detection. The studied phenolics were flavonoids (flavonols: quercentin, rutin, and kaempferol; flavanols: catechin and epicatechin; anthocyanidins: cyanidin and pelargonidin) and phenolic acids (hydroxybenzoic acid derivatives: gallic and ellagic acids; hydroxycinnamic acid derivatives: ferulic, coumaric, and cinnamic acids). The mobile phase consisted in a gradient prepared from formic acid in water (2 %, pH 3) and formic acid in methanol (2 %, pH 3), flow rate 0.7 mL min^?1 at 25 °C. Analyses were performed, using methanol as extractant, before and after acid hydrolysis with the aim of determining free and conjugated phenolic compounds in strawberries. The acid hydrolysis conditions (6 mol L^?1 HCl, 50 min at 90 °C) were shown to be suitable both for phenolic standards and strawberry extracts. Method validation, using phenolic standard solutions, included: linearity study, limits of detection and quantification, and calibration and analytical sensitivity quantifications. Precision and accuracy were studied in strawberry extracts. The results indicate that the developed method was linear, sensible, precise, and accurate, and the convenience of methanol can substitute acetonitrile as the most commonly used solvent in HPLC. The method was employed for knowing the phenolic profile in seven strawberry cultivars from Italy and Argentina, and besides, total phenolic content was analyzed by the Folin–Ciocalteu method; the total antioxidant activity was investigated using the ABTS method. Good correlations were observed among latter parameters, and total phenolics were obtained as the sum of each phenolic compound analyzed by photodiode array detection-HPLC.     

Ferulic, <Emphasis Type="Italic">p</Emphasis>-coumaric,diferulic and triferulic acids contents of corn tortillas prepared with extruded corn flour and enriched with sorghum (<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench) bran

Two ways of adding sorghum bran to tortillas were evaluated; adding to the corn flour before extrusion or after extrusion. The addition of sorghum bran increased the ferulic (FA), p-coumaric (p-CA), diferulic (di-FA) and triferulic (tri-FA) acids contents in corn flours and tortillas. Extrusion produced an increment of the free forms, and a part of the ferulic acid was degraded as a consequence of the extrusion conditions. Baking produced a reduction of bound and free forms of the phenolic acids in tortillas, however, high retention percentage of the phenolic acids was observed in flours and tortillas (83–90%). The antioxidant activity of flour and tortillas were correlated to the contents of the phenolic acids, especially with bound di-FA and tri-FA combined (r?=?0.92). Adding the sorghum bran before extrusion, produced flours with increased free phenolic acids content, and increased in vitro antioxidant activity.     

麦麸发酵前后不同存在形态酚类物质中酚酸含量的变化及其抗氧化活性分析

以小麦麦麸为培养基,采用三株泡盛曲霉进行固态发酵,分别提取并采用高效液相色谱法测定麦麸发酵前后不同存在形态(游离型、酯苷结合型、糖苷结合型、碱解束缚型和酸解束缚型)的酚类物质中酚酸的含量,并通过DPPH自由基清除试验、还原力试验以及抗脂质过氧化试验,研究这些酚类物质的抗氧化活性。结果表明:未经过发酵的麦麸,束缚型酚酸在总酚酸含量中约占总量的80%,其酚酸类成分主要包括对香豆酸、阿魏酸、丁香酸、对羟基苯甲酸、咖啡酸、绿原酸、没食子酸、香草酸和肉桂酸等。发酵后的麦麸,游离型酚类物质的含量显著提高。抗氧化试验的结果显示,麦麸中碱解束缚型的酚类物质和发酵后麦麸的游离型酚类物质的抗氧化性较强。试验结果说明泡盛曲霉能促使被束缚的阿魏酸游离出来,使游离型酚类物质的含量及抗氧化性显著提高;而且抗氧化活性与酚酸的种类及含量有关,咖啡酸、丁香酸和阿魏酸含量高的酚类物质,其抗氧化性也较强。     

Temperature sums experienced before harvest partially determine the post‐maturation juicing quality of oranges grown in the Murrumbidgee Irrigation Areas (MIA) of New South Wales

Fruit acid levels are important to maturity standards for both fresh fruit and juice acceptability for processing oranges. Citrus fruit maturity standards are based on sweetness (Brix), titratable acidity (% acid) and their ratio. Harvest of Navel oranges for fresh juice can extend for up to 3 months (August–October) and for as long as 7 months (November–June) for Valencia oranges after they first reach acceptable fresh market maturity. Juice processors encourage ‘late hanging’ of fruit on trees to secure a continuous supply of fresh juice. During this time, gradual changes occur in % acid, Brix and juice content. This study tested the hypothesis that a significant proportion of the variation in fruit quality late in the harvest season could be accounted for by environmental conditions during the period that the fruits were left on the trees. Fruit juice quality was assessed in terms of Brix and % acid at the time of harvest for 19 000 fruit deliveries during a 9 year period from 1988 to 1996. The relationship between quality (Brix and acid content) and temperature sums (effective heat units—EHUs) for the period the fruits were held on the trees was tested. A temperature sum (‘day degree’) model for predicting relative changes in acid and Brix content of late‐harvested fruit was developed for both Valencia and Navel oranges. The juice acid relationship with EHUs was stronger than the Brix relationship with EHUs. In addition, the seasonal ‘behaviour’ of % acid was more consistent than that of Brix in both Valencia and Navel oranges. A linear reduction in % acid with increasing EHUs was evident in both varieties. Estimates of fruit quality (Brix/acid ratio) at harvest time should be made using the equations describing changes in % acid with EHUs and the relationship between Brix and % acid to determine Brix. These equations have potential use in predicting the internal quality of citrus fruit during extended harvest periods. EHU‐based fruit quality estimates could determine harvest schedules that enable growers to achieve the optimum factory price for their fruit whilst maximising returns to processors through more efficient product utilisation. © 2000 Society of Chemical Industry     

Determination of phenolic composition and antioxidant capacity of blood orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) grown in Turkey

The phenolic compounds and antioxidant capacities of orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) were determined. A high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify phenolic compounds of the orange juices. A total of 18 phenolic compounds were identified and quantified in Moro and Sanguinello orange juices, including hydroxybenzoic acids (2), hydroxycinnamic acids (5), flavanones (5), and anthocyanins (6). It was observed that total phenolic content of Moro juice was higher than that of Sanguinello juice. Ferulic acid was the most dominant hydroxycinnamic acid and cyanidin 3-(6″-malonyl glucoside) and cyanidin 3-glucoside were the most dominant anthocyanins in both cultivars. Antioxidant activities of orange juices were measured using the DPPH^· (2,2-diphenyl-1-picrylhydrazyl) method. According to DPPH^· assays, the antioxidant capacity of Moro juice was found to be higher than that of Sanguinello juice.     

黑小麦麸皮酚酸物质的定性分析与阿魏酸含量测定

对黑小麦麸皮中的主要酚酸物质进行制备和定性分析,并测定阿魏酸含量。采用乙醇和氢氧化钠溶液处理黑小麦麸皮,提取样品中的游离态酚酸(free phenolic acids,FPA)和结合态酚酸(conjugated phenolic acids,CPA)。通过液质联用(LC/MS)和紫外光谱(UV)等方法对提取的酚酸物质进行定性分析。紫外光谱显示,游离态和结合态酚酸具有与阿魏酸相似的分子结构。LC/MS检测结果显示,游离态和结合态酚酸的相对分子质量分别为224和194。由此判断黑小麦麸皮中的游离态酚酸FPA主要为芥子酸,结合态酚酸CPA主要为阿魏酸。采用高效液相色谱(HPLC)对黑小麦麸皮中的结合态阿魏酸含量进行测定。结果表明,紫粒黑小麦麸皮的阿魏酸含量为2.07 mg/g,与蓝粒黑小麦麸皮的阿魏酸含量(2.12 mg/g)相近,其含量高于当地种植的普通小麦麸皮的阿魏酸含量(1.17 mg/g)。     

Occurrence and content of hydroxycinnamic and hydroxybenzoic acid compounds in foods

Phenolic acid compounds seem to be universally distributed in plants. They have been the subject of a great number of chemical, biological, agricultural, and medical studies. Hydroxycinnamic acid compounds occur most frequently as simple esters with hydroxy carboxylic acids or glucose, while the hydroxybenzoic acid compounds are present mainly in the form of glucosides. Furthermore, phenolic acids may occur in food plants as esters or glycosides conjugated with other natural compounds such as flavonoids, alcohols, hydroxyfatty acids, sterols, and glucosides. Also, hydroxycinnamic acid amides appear to be common constituents. The occurrence of the different natural phenolic acid compounds in foods is reviewed, and data of the content in fruit, vegetables, and spices are given. The distribution of the main phenolic acid compounds in food plants as well as their changes during development and maturation of fruits are considered. Furthermore, the hydroxycinnamic acids bound to cell wall polymers, the phenolic acid compounds in coffee, cereals, oil seed, and tree nuts, and the analysis of phenolic acid derivatives are reviewed.     

七种谷物麸皮中酚酸类成分分析

利用反相高效液相色谱法(RP-HPLC)测定7 种不同种类及品种的谷物麸皮中8 种酚酸类成分的含量,并利用数学统计的方法对不同种类谷物、各类酚酸及总酚酸含量间的差异性进行分析。分析结果表明：所分析谷物种类所含酚酸的含量顺序为玉米>小麦>荞麦>燕麦,谷物麸皮中酚酸主要以束缚型酚酸形式存在,且肉桂酸类酚酸含量明显大于苯甲酸类酚酸,游离型及可溶共价结合型酚酸中4- 羟基苯甲酸、香草酸含量较高;而在束缚型酚酸中阿魏酸的含量在各类谷物中均最高,玉米品种中可达到6527.86μg/g 麸皮。     

Phytochemicals and antioxidant activity of different fruit fractions (peel,pulp, aril and seed) of Thai gac (Momordica cochinchinensis Spreng)

Three fractions (peel, pulp and aril) of gac fruit (Momordica cochinchinensis Spreng) were investigated for their phytochemicals (lycopene, beta-carotene, lutein and phenolic compounds) and their antioxidant activity. The results showed that the aril had the highest contents for both lycopene and beta-carotene, whilst peel (yellow) contained the highest amount of lutein. Two major phenolic acid groups: hydroxybenzoic acids and hydroxycinnamic were identified and quantified. Gallic acid and p-hydroxybenzoic acid were found in all fractions. Ferulic acid and p-hydroxybenzoic acid were most evident in pulp. Myricetin was the only flavonoid found in all fractions. Apigenin was the most predominant flavonoid in pulp (red), whereas rutin and luteolin gave the highest content in aril. The extracts of different fractions exhibited different levels of antioxidant activity in the systems tested. The aril extract showed the highest FRAP value. The greatest antioxidant activities of peel and pulp extracts were at immature stage, whereas those in the seed extracts increased from mature stage to ripe stage. The contents of total phenolic and total flavonoid in peel and pulp decreased during the fruit development stage (immature > ripe fruit) and subsequently displayed lower antioxidant capacity, except for the seed.