The distribution of phenolic acids in pumpkin’s hull-less seed,skin, oil cake meal,dehulled kernel and hull

The phenolic acids in whole hull-less seed, its skin and oil cake meal, dehulled kernel and hull of pumpkin (Cucurbita pepo) were separated into free, esterified and insoluble-bound forms, which were then identified and quantified by high-performance liquid chromatography with a photodiode array detector. In all samples, protocatechuic, p-hydroxybenzoic, vanillic, trans-p-coumaric, ferulic, trans-sinapic acids and p-hydroxybenzaldehyde were quantified. Caffeic acid was present in all samples except in hulls, while syringic acid was not detectable only in skin and oil cake meal. p-Hydroxybenzoic acid was the dominant phenolic compound in all investigated samples, with 34.7%, 52.0%, 51.4%, 67.4% and 51.8% found in hull-less seed, oil cake meal, skin, dehulled kernels and hulls, respectively, based on total phenolic acid content. Most phenolic acids were present in bound (esterified and insoluble) form, from 50.6% in skin to 84.1% in hull-less seed.     

Distribution of free,esterified, and insoluble bound forms of phenolics in tea seeds and their antioxidant activity

In this study, phenolic compounds in their phenolic extract (PE), free phenolic (FP), esterified phenolic (EFP), and insoluble bound phenolic (ISBP) forms were extracted from tea seeds and quantified using HPLC to obtain information on the phenolics that are present in tea seeds along with their antioxidant activities. The total phenolic content of the ISBP fraction was higher than that of the FP and EFP fractions. The phenolic acids in tea seeds exist either in esterified or glycosided forms. Moreover, hydroxycinnamic acid derivatives have been identified as important phenolic acid components in tea seeds. The ISBP fraction was an effective antioxidant based on the results obtained from the in vitro assays performed, which include the DPPH and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)-derived nitrogen-centered radical scavenging activities, Fe³⁺-2,4,6-tripyridyl-s-triazine reducing ability, as well as Cu²⁺ and Fe²⁺ ion chelating effects.     

Antioxidant Properties of Free,Soluble Ester and Insoluble‐Bound Phenolic Compounds in Different Barley Varieties and Corresponding Malts

Ten different barley cultivars and their corresponding malts were used to obtain different fractions. Phenolics extracted belonged to free, soluble esters and insoluble‐bound fractions. Total phenolic content (TPC) of the free fraction, as measured according to the Folin‐Ciocalteu method, ranged from 37.7 to 167.2 mg gallic acid equiv/kg of dried material (GAE/kg_dw) for barley and between 34.1 and 72.3 mg GAE/kg_dw for malt. The bound phenolic content ranged from 210.3 to 320.5 and between 81.1 and 234.9 mg GAE/kg_dw for barley and malt, respectively. The contribution of bound phenolics to the TPC was significantly higher than that of free and esterified fractions. Catechin and ferulic acid, quantified by high performance liquid chromatography with diode array detector (HPLC‐DAD), were the most abundant phenolics in the free and bound fractions, respectively. The p‐coumaric acid content was lower in hulless genotypes, as compared to hulled genotypes, showing that it is mainly concentrated in the hull. The antioxidant activities of the phenolic fractions were investigated using the radical scavenging assay (DPPH) and ferricyanide reducing power. The bound phenolics demonstrated a significantly higher antioxidant capacity compared to the free and esterified phenolics. During the malting process, a significant decrease of the bound phenolics was observed with a corresponding increase of the esterified fraction.     

Characterization of free,esterified and bound phenolics in custard apple (Annona squamosa L) fruit pulp by UPLC-ESI-MS/MS

Ultra high-performance liquid chromatography-electrospray ionization mass spectrometry (UPLC-ESI-MS) was used to identify the free, bound and esterified phenolic acids in the extracts of custard apple (Annona squamosa L). In total around 16, 15 and 13 free, bound and esterified phenolic compounds respectively were identified. Among these about 5 phenolic compounds like quinic acid, gallocatechin, gallocatechin gallate, caffeoylhexoside, dihydroxyquercetin have and been reported for the first time in A. squamosa. Also, compounds like 4-(β-d-glucopyranosyloxy) benzoic acid, procyanidin B1, procyanidin C1 in free form, 7 hydroxycoumarin 7 glucoside (skimmin), dihydroquercetin, xanthotaxol acetate, decycloxybenzoic acid in bound extract and caffeoyl hexoside in esterified form have been tentatively identified. Apart from phenolic compounds few organic acids like malic, citric, citramalic, adipic and acotinic acid have been found in the custard apple extracts. This study provides a newer insight into the phenolic profile of custard apple and their characterization by UPLC-ESI-MS/MS.     

核桃内种皮不同形态酚酸类化合物的溶剂提取率比较

该文研究溶剂对核桃内种皮中不同形态酚酸类化合物的提取率,建立了适用于核桃内种皮中酚酸类化合物的提取方法.以新疆核桃为原料,比较不同比例的甲醇、乙醇溶液对核桃内种皮中可溶性游离态、可溶性酯化态和不溶性结合态酚酸的提取率.结果表明,50％(体积分数,下同)甲醇适合提取可溶性游离态绿原酸、没食子酸;50％(体积分数,下同)乙...     

Nutritional value, functional properties and nutraceutical applications of black cumin (Nigella sativa L.): an overview

Non‐conventional seeds are being considered because their constituents have unique chemical properties and may augment the supply of nutritional and functional products. Black cumin (Nigella sativa L.) seeds and its crude or essential oils have been widely used in traditional nutritional and medicinal applications. Consequently, black cumin has been extensively studied for its nutritional value and biological activities. The black cumin oilseed had been shown to be anticancer, antidiabetic, antiradical and immunomodulator, analgesic, antimicrobial, anti‐inflammatory, spasmolytic, bronchodilator, hepatoprotective, antihypertensive and renal protective. Moreover, black seeds have many antioxidative properties and activities. In consideration of potential utilisation, detailed knowledge on the composition of black cumin oilseed is of major importance. The diversity of applications to which black cumin can be put gives this oilseed great industrial importance. This review summarises the nutritional value, functional properties and nutraceutical applications of black cumin (N. sativa L.) oilseeds.     

超高压预处理对西番莲果皮抗氧化能力及对HepG2细胞氧化损伤保护作用的影响

酚类化合物以游离态、酯化态和不溶性结合态存在于植物中,本实验通过超高压预处理紫色西番莲果皮(the peel of Passiflora edulis Sims,PEP),研究超高压预处理后PEP游离态、酯化态和结合态酚类化合物的多酚含量、抗氧化活性和细胞保护作用的变化,从而确定超高压预处理对PEP抗氧化能力及对Hep...     

Bioactive phenolic compounds of cowpeas (Vigna sinensis L). Modifications by fermentation with natural microflora and with Lactobacillus plantarum ATCC 14917

In this work we have determined the phenolic composition of raw cowpeas (Vigna sinensis L) of the variety Carilla by HPLC/PAD/MS and have studied the effect of fermentation, both spontaneous and with Lactobacillus plantarum ATCC 14917, on the phenolic compounds. This variety contains mainly ferulic and p‐coumaric acids esterified with aldaric acids, together with the cis and trans isomers of the corresponding free acids. Hydroxybenzoic acids such as gallic, vanillic, p‐hydroxybenzoic and protocatechuic were also found, along with flavonols such as a myricetin glucoside, mono‐ and diglycosides of quercetin and a quercetin diglycoside acylated with ferulic acid. Fermentation, both spontaneous and inoculated, modifies the content of phenolic compounds, but differently in each case. The antioxidant activity as free radical‐scavenging activity has also been evaluated. Fermentation followed by heating has been shown to be a very effective process to increase the functionality of this variety of V sinensis. For this reason, this cowpea variety could be used as an ingredient to obtain high value‐added flours. Copyright © 2004 Society of Chemical Industry     

Antioxidant potency of cumin varieties—cumin, black cumin and bitter cumin—on antioxidant systems

Cumin is one of the commonly used spices in food preparations. It is also used in traditional medicine as a stimulant, a carminative and an astringent. In this study, we characterized the antioxidant activity of three commercially available cumin varieties, viz., cumin (Cuminum cyminum), black cumin (Nigella sativa) and bitter cumin (C. nigrum). The antioxidant capacity of cumin varieties was tested on Fe²⁺ ascorbate induced rat liver microsomal lipid peroxidation, soybean lipoxygenase dependent lipid peroxidation and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging methods. The total phenolic content of methanolic extracts of cumin varieties ranged from 4.1 to 53.6 mg g^–1 dry weight. Methanolic extracts of all the three varieties of cumin showed higher antioxidant activity compared with that of the aqueous extract. Among the cumin varieties, bitter cumin showed the highest antioxidant activity followed by cumin and black cumin in different antioxidant systems. IC₅₀ values of the methanolic extract of bitter cumin were found to be 0.32, 0.1 and 0.07 mg dry weight of cumin seeds on the lipoxygenase dependent lipid peroxidation system, the DPPH radical scavenging system and the rat liver microsomal lipid peroxidation system, respectively. The data also show that cumin is a potent antioxidant capable of scavenging hydroxy, peroxy and DPPH free radicals and thus inhibits radical-mediated lipid peroxidation. The high antioxidant activity of bitter cumin can be correlated to the high phenolic content among the three cumin varieties. Thus, bitter cumin with a high phenolic content and good antioxidant activity can be supplemented for both nutritional purposes and preservation of foods.     

Phenolic acids in the meal of developing and stored barley seeds

The following free phenolic acids were identified in the meal of developing barley seeds: salicylic, p-hydroxybenzoic, vanillic, protocatechuic, o-, m- and p-coumaric, syringic, ferulic and sinapic acids. The highest concentration of these compounds was observed at 19–31 days after anthesis. At this time the highest amount of total ethanol-soluble, bound phenolic acids was also found. In the ripe seeds or seeds stored for 2–6 weeks after harvesting, the content of free and soluble bound phenolic acids was distinctly lower. No free caffeic or chlorogenic acids were detected in the seeds by the procedure applied.     

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.     

Antiproliferative and antioxidant activities of Turkish pomegranate (Punica granatum L.) accessions

The objective of this study was to assess antioxidant and antiproliferative activities of four different Turkish pomegranate varieties (Hatay, Hicaz, Adana and Antalya) using an in vitro HepG2 cancer cell model. All the pomegranate extracts employed in this study significantly diminish the proliferation of HepG2 cells in a dose‐dependent manner. The total phenolic acid, anthocyanin and flavonoid contents for each of the four varieties were determined. The Hatay pomegranate variety had the highest total phenolic acid (337.4 ± 2.34 mg/100 g) and flavonoid (58.42 ± 2.25 mg/100 g) contents of the pomegranates examined. Antioxidant activities of the pomegranates were determined using DPPH and ABTS radical scavenging assays. The lack of correlation between colour index value and antioxidant–antiproliferative activities suggested that phenolic acids and flavonoids are predominant compounds influencing pomegranate's bioactivity rather than anthocyanins. Individual phenolic acids found in Hatay pomegranates were determined, using an HPLC system, as gallic acid being the most predominant phenolic compound.     

The phenolic acid and polysaccharide composition of cell walls of bran layers of mature wheat (Triticum aestivum L. cv. Avalon) grains

The purpose of this study was to examine the carbohydrate and phenolic‐ester composition of cell walls in wheat bran layers. Four defined layers of wheat bran were separated manually from mature grains of wheat (Triticum aestivum L. cv. Avalon) to give samples of beeswing bran (outer pericarp), cross cells, testa + nucellar epidermis and aleurone cells. The cell‐wall material from each layer, and from a sample of intact bran, was analysed for carbohydrates and wall‐bound esterified phenolic acids. The cell‐wall material of intact bran was rich in arabinose and xylose with significant quantities of glucose and uronic acid and a relatively small amount of galactose and mannose. The varying ratios of arabinose:xylose in cell walls of isolated bran layers indicated that the heteroxylans had tissue‐specific substitution patterns. HPLC analysis of phenolic acids identified significant amounts of esterified ferulic acid and 8‐8′‐ (aryltetralin form), 5‐8′‐, 5‐5′‐, 8‐0‐4′‐ and 5‐8′‐(benzofuran form)‐dehydrodiferulic acids in the isolated cell walls. Ferulic acid was highly concentrated in the aleurone layer, whereas dehydrodiferulates were concentrated in the beeswing bran and cross cells. The role of phenolic cross‐linking is discussed in relation to the architecture of the cell walls of wheat bran and to processing implications. Copyright © 2005 Society of Chemical Industry     

Antioxidant and antibacterial activities of polyphenolic compounds from bitter cumin (Cuminum nigrum L.)

Cumin is one of the commonly used spices in food preparations. It is also used in traditional ayurvedic medicine as a stimulant, carminative and astringent. Earlier we have reported that bitter cumin (Cuminum nigrum L.) possess the most potent antioxidant activity among cumin varieties—cumin, black cumin and bitter cumin. In this study, we have further characterized the polyphenolic compounds of bitter cumin and also their antioxidant and antibacterial activity using different model systems. The major polyphenolic compounds of cumin seeds were extracted with 70% methanol, 70% acetone, water, separated by HPLC and their structures were elucidated by LC-MS. The profile of phenolic acids/flavonols in bitter cumin were found to be gallic acid, protocatechuic acid, caffeic acid, ellagic acid, ferulic acid, quercetin and kaempferol. The antioxidant activity of the cumin extract was tested on 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging, soybean lipoxygenase-dependent lipid peroxidation, rat liver microsomal lipid peroxidation and superoxide anion (O²⁻) scavenging. The bitter cumin extract exhibited high antioxidant activity with IC₅₀ values of 14.0±0.5 μg, 28.0±3.0 μg, 110±14.0 μg and 125.4±8.7 μg of the extract, respectively for DPPH free radical scavenging, soybean lipoxygenase-dependent lipid peroxidation, rat liver microsomal lipid peroxidation and superoxide anion scavenging. Further, the extract offered a significant protection against DNA damage induced by hydroxyl radicals. Among a spectrum of food-borne pathogenic and spoilage bacteria tested, the cumin extract significantly inhibited the growth of Bacillus subtilis, Bacillus cereus and Staphylococcus aureus. Thus, bitter cumin with an array of polyphenolic compounds possesses potent antioxidant and antibacterial activities.An erratum to this article can be found at     

Color of whole-wheat foods prepared from a bright-white hard winter wheat and the phenolic acids in its coarse bran

Abstract: The color of wheat kernels often impacts the color and thereby the value of wheat‐based foods. A line of hard white winter wheat (B‐W HW) with bright appearing kernels has been developed at the Kansas State Agricultural Research Center. The objective of this study was to compare the color of several foods made from the B‐W HW wheat with those of 2 hard white wheat cultivars, Trego and Lakin. The B‐W HW kernels showed higher lightness (L*, 57.6) than Trego (55.5) and Lakin (56.8), and the increased lightness was carried over to its bran and whole‐wheat flour. Alkaline noodle and bread crumb made from the B‐W HW whole‐wheat flour showed slightly higher lightness (L*) than those made from Trego and Lakin. The sum of soluble and bound phenolics extracted from the 3 wheat brans, which had not been preextracted to remove lipids, was found to be 17.22 to 18.98 mg/g. The soluble phenolic acids in the brans were principally vanillic, ferulic, and syringic. The bound phenolic acids in the brans were dominated by ferulic, which accounted for 50.1% to 82.2% of total identified bound phenolic acids. Other bound phenolic acids were protocatechuic, caffeic, syringic, trans‐cinnamic, p‐hydroxybenzoic, p‐coumaric, and vanillic. The lightness (L*) values of coarse wheat brans correlated positively with their levels of bound protocatechuic (r = 0.72, P < 0.01) and p‐hydroxybenzoic acids (r = 0.75, P < 0.01).     

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 treatment initially decreased and subsequently increased FPC content, but bound phenolic compounds (BPC) decreased during incubation. Chitosan + A. flavus treatments caused an increase in FPC that reached a plateau between 24–48 h at Aw .85 while BPC levels increased over the same time period at both Aw levels. The major free and bound phenolic acids detected were p‐coumaric and ferulic acids and an unknown phenol that eluted at a retention time of 22 min. Generally, chitosan treatment 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 treatment caused significant induction of bound p‐coumaric and ferulic acids and free unknown phenol at Aw .85. Chitosan + A. flavus treatment measure to reduce or eliminate pre‐harvest contamination by A. flavus and aflatoxins contributes to sustainable agriculture, especially to developing countries.

The enhanced elicitation of preformed phenolic compounds by chitosan may provide seed tissues an additive or synergistic effect in controlling aflatoxin‐producing fungi and preventing aflatoxin contamination. Further, such investigation will help elucidate the biochemical basis of elicitor‐host interaction that contribute to defensive responses of host tissues. Identification of biochemical factors in induced resistance involves a refinement in the separation and identification of induced phenolic compounds. Methodologies such as spectrophotometric assay or reverse‐phase high performance liquid chromatography (HPLC) may be used to evaluate phenolic compound induction by these elicitors. In addition, these compounds can be tested on their effects on A. flavus mycelial growth and subsequent aflatoxin production in vitro.

Hence, a study on the possible role of phenols on the natural resistance of peanuts to A. flavus invasion was conducted with the following objectives: 1) to quantitate changes in free and bound phenolic compounds influenced by chitosan, A. flavus, and water activity (Aw) levels by Folin‐Ciocalteu assay; 2) to separate, identify, and quantitate free and bound phenolic acids influenced by elicitors and Aw levels; and 3) to determine the effects of phenolic acids in liquid cultures at different concentrations on mycelial growth and aflatoxin B₁ production by A. flavus.     

Probiotic fermented milk with high content of polyphenols: Study of viability and bioaccessibility after simulated digestion

This research evaluated the functional potential of a fermented milk made with Streptococcus thermophilus, a probiotic (Bifidobacterium animalis subsp. lactis) and pomegranate juice. Ferric‐reducing antioxidant potential, Trolox equivalent antioxidant capacity, scavenging effect on 1,1‐diphenyl‐2‐picrylhydrazyl free radical, oxygen radical absorbance capacity and Folin–Ciocalteu assays were used to estimate antioxidant activity and phenolic content. Probiotic survival, release and absorption of polyphenols were evaluated using in vitro gastrointestinal digestion. The concentration of polyphenols increased during digestion from 608 mg to 1417  gallic acid equivalents (GAE) /L. About 14% of polyphenols were found on the dialysate portion. The beverage presented high viability of probiotics with high survival rate after digestion (above 7 log cfu/mL).     

Distribution of insoluble bound phenolic acids in barley grain

Insoluble bound phenolic acids were analysed by g.l.c. and by h.p.l.c. in eight abraded fractions of barley grain. Vanillic, p-coumaric, ferulic and diferulic acids were identified in all the fractions. Ferulic and p-coumaric acids were quantitatively the most important. The outer layers, comprising husks, pericarp, testa and aleurone cells, contained the highest concentrations of total phenolic acids (0.6–0.9%) while their concentrations were considerably lower in the endosperm layers (0.1% or less). Calculated on the basis of the cell wall content in the fractions, the highest concentration of ferulic acid was found in fractions enriched with aleurone cells while the highest concentration of p-coumaric acid was found in fractions containing high levels of husks.     

Determination of phenolic acids in plant cell walls by microwave digestion

Microwave digestion (750 W for 90 s) with 4 M NaOH was used to release esterified and etherified hydroxycinnamic acids from cell walls of maize (Zea mays L), wheat (Triticum aestivum L), barley (Hordeum vulgare L) and oilseed rape (Brassica napus L) stems. Subtraction of values for saponifiable phenolic acids obtained after treatment with I M NaOH at room temperature from digest results provided a measure of β-ether linked units. These were exclusively (E + Z)-ferulic acid in the cereal straws. Only trace amounts of ether- and ester-linked hydroxycinnamic acids were released from the dicotyledon, ripe straw. Microwave digestion was shown to be an order of magnitude more effective than dioxane-HCl at liberating β-ether bound phenolic acids and as effective, but substantially quicker, than previously described high-temperature alkaline digestions.     

Apparent ileal digestibility of amino acids in feed ingredients determined with broilers and layers

The apparent ileal digestibility of amino acids in eight feed ingredients were determined using broilers and layers. The ingredients included three cereals (wheat, sorghum and maize), one cereal by‐product (wheat middlings), three oilseed meals (canola, cottonseed and soybean meals) and one animal protein meal (meat and bone meal). Dietary protein in the assay diets was supplied solely by the test ingredient. All diets contained 20 g kg^?1 acid‐insoluble ash as an indigestible marker, and each diet was offered ad libitum in mash form to five replicate pens of 42‐day‐old broilers and 60‐week‐old layers. The digestibility coefficients of most amino acids for wheat and sorghum were similar (P > 0.05) in broilers and layers. The digestibility of most amino acids for maize was higher (P < 0.05) in broilers compared to those in layers. The digestibility of individual amino acid for wheat middlings was higher (P < 0.05) in layers than in broilers. In general, the digestibility of amino acids for cottonseed meal, soybean meal, and meat and bone meal were similar (P > 0.05) between broilers and layers. The influence of class of bird on digestibility in canola meal was variable. The digestibility of threonine, valine, isoleucine, leucine, phenylalanine, glutamic acid and alanine were higher (P < 0.05), and those of methionine, histidine and lysine were lower (P < 0.05) in broilers compared to layers. These results suggest that the practice of using amino acid digestibility values generated with broilers for layers may not be appropriate for all feed ingredients. Copyright © 2006 Society of Chemical Industry