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1.
The prefermentation addition of copigments led to significantly different red wines according to the copigment structure (flavonol or hydroxycinnamic acid) and the grape cultivar [Tempranillo (= Cencibel) or Cabernet Sauvignon]. The flavonol rutin enhanced copigmentation and anthocyanin extraction, improving the red color, but the hydroxycinnamic acids (especially caffeic acid) had converse results. The above effects were higher in Cabernet Sauvignon wines, particularly if rutin or p-coumaric acid was used. These wines showed the highest copigmentation as they contained more anthocyanins and flavonols, whereas the coumaroylated anthocyanins of Tempranillo wines could have prevented the action of the added copigments. After 21 months, the main pyranoanthocyanins found were the malvidin-3-glucoside 4-vinylphenol and the malvidin-3-glucoside 4-vinylcatechol (pinotin A) adducts. The results suggested that the former adduct was primarily generated following enzymatic decarboxylation of p-coumaric acid during fermentation, whereas pinotin A was formed through a pure chemical reaction, which depended on the concentration of free caffeic acid during aging.  相似文献   

2.
The effectiveness of seven phenolic compounds (catechin, epicatechin, procyanidin B2, caffeic acid, p-coumaric acid, myricitrin, and quercitrin) as copigments of malvidin 3-glucoside, the major anthocyanin in red wines from Vitis vinifera, using a copigment/pigment molar ratio of 1:1 was assayed in model wine solutions under the same conditions (pH=3.6, 12% ethanol). The stability of the copigment-pigment complexes formed was studied during a storage period of 60 days at 25 degrees C. Tristimulus colorimetry was applied for color characterization of the copigmentation process, and HPLC-DAD-MS was used to monitor changes in the composition of the samples. Copigmentation has been found to occur in all cases despite the low copigment/pigment molar ratio used, although the effect was different depending on the compound. Flavan-3-ols appeared as the less effective copigments, procyanidin B2 being even worse than monomeric flavanols, whereas flavonols behaved as the best ones. These latter copigments also induced the most statistically significant bathochromic shift in lambdamax. In the colorimetric analysis, it was observed that the lightness L* of the copigmented solutions increased with time, chroma C*ab decreased, and the hue hab increased. The copigments that produced a greater increase in the hue angle were the monomeric flavan-3-ols, which therefore showed to be the least protective cofactors against browning of the anthocyanin solution during the storage. With the time of storage, the formation of new pigments was observed in the solutions containing flavanols (xanthylium structures) and hydroxycinnamic acids (pyranoanthocyanins), which explains some of the color modifications produced in these solutions. Another relevant observation was that the stability of the anthocyanin was not much improved by most of the assayed copigments, since quite similar degradation rates were observed in the presence and absence of those cofactors.  相似文献   

3.
Anthocyanin extracts are increasingly used as food ingredients. A current challenge is to maintain their color properties. The stability of some colorants has been studied in sugar and non-sugar drink models at three pH values (3, 4, and 5) under thermal and light conditions simulating rapid food aging. At a given pH, color stability mainly depends on the structures of anthocyanins and of colorless phenolic compounds. Colorants rich in acylated anthocyanins (purple carrot, red radish, and red cabbage) display great stability due to intramolecular copigmentation. The protection of red chromophore is higher for diacylated anthocyanins in red radish and red cabbage. For colorants without acylated anthocyanins (grape-marc, elderberry, black currant, and chokeberry), intermolecular copigmentation plays a key role in color protection. Colorants rich in flavonols and with the highest copigment/pigment ratio show a remarkable stability. By contrast, catechins appear to have a negative effect on red colorants, quickly turning yellowish in drink models. This effect is more pronounced when the pH is increased. Finally, color does not seem to be greatly influenced by the addition of sugar.  相似文献   

4.
The purpose of this investigation was to report on the total phenolics, anthocyanins, and oxygen radical absorbance capacity (ORAC) of strawberry, peach, and apple, the influence of dehydration and ascorbic acid treatments on the levels of these compounds, and the effect of these treatments on fruit color. Results showed that fresh strawberry had the highest levels for total phenolics [5317.9 mg of chlorogenic acid equivalents (CAE)/kg], whereas lower levels were found in fresh apple and peach (3392.1 and 1973.1 mg of CAE/kg, respectively), and for anthocyanins (138.8 mg/kg), whereas lower levels were found in fresh apple and peaches (11.0 and 18.9 mg/kg, respectively; fresh strawberry had an ORAC value of 62.9 mM/kg Trolox equivalents. The fresh apple and peach were found to have ORAC values of 14.7 and 11.4 mM/kg of Trolox equivalents, respectively. The color values indicated that the addition of 0.1% ascorbic acid increased the lightness (L) and decreased the redness (a) and yellowness (b) color values of fresh strawberry, peach, and apple, sliced samples, and the puree made from them. Also, results showed that dehydration is a good method to keep the concentrations of total phenolics and anthocyanins and ORAC values at high levels.  相似文献   

5.
Intermolecular copigmentation reactions are significantly responsible for the manifold color expression of fruits, berries, and their products. These reactions were investigated with five anthocyanins and five phenolic acids acting as copigments. The stability of the pigment-copigment complexes formed was studied during a storage period of 6 months. The study was conducted using a UV-visible spectrophotometer to monitor the hyperchromic effect and the bathochromic shift of the complexes. The greatest copigmentation reactions took place in malvidin 3-glucoside solutions. The strongest copigments for all anthocyanins were ferulic and rosmarinic acids. The immediate reaction of rosmarinic acid with malvidin 3-glucoside resulted in the biggest bathochromic shift (19 nm) and the strongest hyperchromic effect, increasing the color intensity by 260%. The color induced by rosmarinic acid was not very stable. The color intensity of pelargonidin 3-glucoside increased greatly throughout the storage period with the addition of ferulic and caffeic acids.  相似文献   

6.
A novel membrane chromatographic method with a membrane adsorber (Sartobind S) has been developed on the laboratory scale that allows a fractionation of bilberry (Vaccinium myrtillus) constituents into the following three groups of polyphenols: anthocyanins, copigments, and polymers. By using this methodology, a pure anthocyanin fraction free of other copigments and polymeric phenols can be obtained. Using this approach, it provides fractions allowing a more thorough testing of the biological effects of the individual groups of bilberry polyphenols as well as the study of possible synergistic effects between these different groups of bioactive constituents from bilberry.  相似文献   

7.
In this study the impact of achenes on polyphenolic compounds, ascorbic acids, and antioxidant activities in strawberry purees at production and after storage at 6 and 22 degrees C for 8 and 16 weeks was investigated. Strawberry purees were made from flesh, berry, and achene-enriched homogenate and contained 0, 1.2, and 2.9% achenes, respectively. At production, strawberry purees made from flesh contained more anthocyanins, p-coumaroyl glycosides, and ascorbic acids, whereas increasing achene levels caused increasing levels of ellagic acid derivatives, proanthocyanidins, flavonols, total phenolics (TP), and antioxidant activities. In addition, the anthocyanins, TP, and ferric reducing ability power (FRAP) in purees with more achenes were better retained during storage. Ascorbic acids and anthocyanins declined rapidly during storage, whereas other polyphenols and antioxidant activities were more stable; that is, the contributions from anthocyanins and ascorbic acids to TP and antioxidant activities decreased. The findings that achenes contributed significantly to polyphenol content and stability of strawberry purees may be interesting in a nutritional and, thus, commercial, perspective.  相似文献   

8.
Stability and enhancement of berry juice color   总被引：5，自引：0，他引：5  
Attractive color is one of the main sensory characteristics of fruit and berry products. Unfortunately, the color of red juices is unstable and easily susceptible to degradation, leading to a dull and weak juice color. This study was designed to investigate the color stability and copigmentation of four different berry juices enhanced by phenolic acids and commercial color enhancers. Phenolic acid enrichment improved and stabilized the color of the berry juices during storage. The commercial color enhancers immediately produced an intensive color to the juices, which, however, was not very stable. The color enhancement was intensive in strawberry and raspberry juices and effective in lingonberry and cranberry juices. Sinapic acid induced the strongest color in strawberry juice. Ferulic and sinapic acids improved raspberry juice color equally. Rosmarinic acid enhanced the color of lingonberry and cranberry juices the most. The addition of the simple cinnamic acids produced novel peaks to the end of the high-performance liquid chromatography chromatogram, indicating a formation of new compounds. It can be assumed that sinapic and ferulic acids formed new intramolecular copigmentation compounds with berry anthocyanins whereas rosmarinic acid stabilized anthocyanins intermolecularly.  相似文献   

9.
The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of all polyphenols dramatically decreased throughout fermentation when pressing was achieved immediately after FR. The FR wines made with pomace maceration were also enriched in polyphenols compared to the corresponding control wines. Increasing the duration of high-temperature exposure in the FR treatment further increased extraction of phenolic compounds but also accelerated their conversion to derived species. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase, higher after FR than in the control, and even higher after longer heating. FR resulted in an increased tannin-to-anthocyanin ratio and an increased conversion of anthocyanins to tannin-anthocyanin adducts showing the same color properties as anthocyanins. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase that also contained larger amounts of orange sulfite bleaching-resistant pigments.  相似文献   

10.
A red wine with appropriate basic quality characteristics for aging was stored in oak barrels for 12 months and then bottled and aged for a further 6 months. The same ambient conditions of temperature and humidity were maintained throughout the entire aging process. The barrels used were made from three different species of oak by four different cooperages and had been used for at least two years. Analysis of variance and principal component analysis were run on the values for hexoses, pentoses, total anthocyanins, ortho-diphenols, low- and high-polymer polyphenols, and color parameters to study the behavior of the monosaccharides and polyphenols in response to the factors of aging time, the oak variety employed, and the source cooperage where the barrels had been made. Time trends for all the phenolic components were directly related to aging time, with low-polymeric polyphenols (LPPs) being the most affected by wood type and source cooperage. Wine color was defined by a basic red color which decreased with aging time in the barrel and was altered by yellowish pigment components differing for each of the barrels in which oxidative aging took place and by increased stability of the blue copigments. Principal component analysis showed that samples of the same source wine aged in different barrels tended to be grouped together according to each of the aging intervals considered.  相似文献   

11.
Degradation parameters of purified anthocyanins from purple-fleshed potato (cv. Purple Majesty) heated at high temperatures (100-150 °C) were determined. Purified anthocyanins, prepared by removing salts, sugars, and colorless nonanthocyanin phenolics from the crude extract, were monitored and quantified using HPLC and spectrophotometry for heat-induced degradation products. Separation of colorless phenolics from the anthocyanins was confirmed using HPLC at two wavelengths, 280 and 520 nm. The degradation kinetics of purified anthocyanins followed a first-order reaction with reaction rate constants (k values) of 0.0262-0.2855 min(-1), an activation energy of 72.89 kJ/mol, thermal death times (D values) of 8.06-8789 min, and a z value of 47.84 °C over the temperature range of 100-150 °C. The enthalpy and entropy of activation were 59.97 kJ/mol and -116.46 J/mol·K, respectively. The antioxidant capacity in the purified anthocyanins, measured by DPPH and ABTS assays, was increased after the thermal treatment, indicating antioxidant activities of degradation products in the samples.  相似文献   

12.
Numerous in vitro and in vivo studies have suggested that dietary anthocyanins and ellagitannins or ellagic acid might have beneficial health effects. Epidemiological evidence on the disease-preventing potential of these polyphenols is lacking, due to the absence of reliable data on their contents in foods. In this study was analyzed the content of anthocyanins and ellagitannins (as ellagic acid equivalents after acid hydrolysis) in foods consumed in Finland, including berries, fruits, vegetables, and processed products, using high-performance liquid chromatographic (HPLC) methods. Anthocyanins were detected in 41 of 54 selected food items. The total anthocyanin content varied in berries from 1 to 611 mg/100 g, in fruits from 2 to 66 mg/100 g, and in vegetables from 3 to 75 mg/100 g of fresh weight as the weight of the aglycone. Ellagitannins were screened in 33 food items, but were detected only in 5 species of berries, that is, in cloudberry, raspberry, rose hip, strawberry, and sea buckthorn, the content ranging from 1 to 330 mg/100 g. The results underscore the superiority of berries, especially dark blue or red berries, as excellent sources of anthocyanins and certain berries of the Rosaceae family as the major source of ellagitannins in the Finnish diet.  相似文献   

13.
The bioavailability of anthocyanins from raspberry extracts was assessed using an in vitro digestion procedure that mimics the physiochemical and biochemical changes that occur in the upper gastrointestinal tract (GIT). Effectively all of the total phenol content of the raspberry extract survived gastric digestion and partitioned between the IN sample, which represents the serum available material, and the OUT sample, which represents the material that remains in the GIT and passes through to the colon. All of the anthocyanins also survived gastric digestion, but only approximately 5% entered the IN sample and approximately 70% of total anthocyanins were recovered in the IN and OUT samples. Codigestion of the raspberry extract with commonly combined foodstuffs such as bread, breakfast cereal, ice cream, and cooked minced beef gave a different pattern. The total phenol content of the IN samples was slightly reduced by codigestion with ice cream or breakfast cereal but unaffected by codigestion with bread or minced beef. In most cases, the phenol contents of the postgastric and OUT samples were reduced as compared with the expected values. However, the anthocyanin content of the IN samples was unaffected or increased by coincubation with the foodstuffs. This suggests that polyphenols transiently bind to food matrices during digestion, which protects the more labile anthocyanins from degradation, and they are free to diffuse into the IN sample. The anthocyanin composition of the bioavailability samples was monitored by liquid chromatography-mass spectrometry. All eight anthocyanins previously identified in raspberry were detected in the extract and the postgastric samples at similar yields. All eight anthocyanins could be discerned in the IN and OUT samples, but some such as cyanidin-3-O-glucoside were greatly reduced and others such as pelargonidin-3-O-glucoside were apparently increased in abundance. These differences in stability and their importance for the bioavailability of anthocyanins are discussed.  相似文献   

14.
杨梅澄清汁及浓缩汁中花色苷热降解动力学的研究   总被引：3，自引：1，他引：3       下载免费PDF全文
杨梅花色苷易受温度、pH值等因素的影响而发生降解，是导致产品外观品质变劣的主要原因。本文研究了杨梅澄清汁及浓缩汁内花色苷在不同pH值和不同加热温度下的热稳定性。花色苷降解动力学数据的分析结果表明：杨梅花色苷热降解属动力学一级反应，随着pH值和温度的升高，杨梅花色苷降解的半衰期(t1/2)和热降解活化能(Ea)显著下降，即花色苷的降解速度增大；同一处理条件下，浓缩果汁的t1/2明显低于澄清汁。而反应速率常数k和Ea值大于澄清果汁，说明澄清汁花色苷的热稳定性优于浓缩汁。  相似文献   

15.
Pulsed electric field (PEF) treatments were applied to increase the polyphenolic content of fresh red wines made from Aglianico and Piedirosso grapes. Prior to the fermentation/maceration step, the grape skins were treated at different PEF intensities (field strengths from 0.5 to 1.5 kV/cm and energy inputs from 1 to 50 kJ/kg), with their permeabilization being characterized by electrical impedance measurements. Furthermore, the release kinetics of the total polyphenols and anthocyanins were characterized during the maceration stage by spectroscopic and Folin-Ciocalteu colorimetric methods, respectively. Finally, the fresh wine, obtained after pressing, was characterized for total acidity, pH, reducing sugar, color intensity, total polyphenols, anthocyanins content, antioxidant activity, and volatile compound composition. PEF treatment on Aglianico grapes induced a significantly higher release of polyphenols (+20%) and anthocyanins (+75%), thus improving the color intensity (+20%) and the antioxidant activity of the wine (+20%) while preserving the other organoleptic characteristics. In contrast, there was only a minor impact on the polyphenolic release kinetics of Piedirosso grapes, despite the significant degree of cell membrane permeabilization.  相似文献   

16.
New colorimetric variables have been defined in the uniform CIELAB color space to assess the quantitative and qualitative color changes induced by copigmentation and their incidence on visual perception. The copigmentation process was assayed in model solutions between malvidin 3-glucoside and three phenolic compounds (catechin, epicatechin, and caffeic acid) as a function of the pH and the pigment/copigment molar ratio. Along the pH variation, the greatest magnitude of copigmentation was obtained at pH 3.0, being significantly higher with epicatechin and caffeic acid. At high acidic pH, the main contribution of copigmentation to the total color was qualitative, whereas between pH 2.0 and 4.0, the main colorimetric contribution was quantitative. The contribution of epicatechin and caffeic acid to the color changes was more marked for the quantitative characteristics. On contrast, particularly at higher pH values, the qualitative contribution was more important in catechin copigmented solutions. Increasing copigment concentration induced perceptible color changes at molar ratios higher than 1:2, consisting in a bluish and darkening effect of the anthocyanin solutions. Among the different CIELAB attributes, hue difference was the best correlated parameter with the increase of copigment concentration, proving the relevance of this physicochemical phenomenon on the qualitative changes of anthocyanin color.  相似文献   

17.
Crude anthocyanins extracted from grape skin were solubilized in hexane containing 100 mM bis(2-ethylhexyl)sodium sulfosuccinate (AOT) by forming stable reverse micelles (RMs). Anthocyanins solubilized in RMs showed about four times greater color intensity than that in aqueous medium. The color intensity of anthocyanins in RMs was primarily affected by the interaction between sulfonate head of AOT and flavylium cation of anthocyanins. The molar ratio of water to AOT (Wo) also influenced the color properties. As the Wo increased from five to 20, the color intensity increased and resulted in a bathochromic shift. This result suggests that increased micelle size facilitates complexation between AOT and flavylium cation. The color stability of anthocyanins in RM was higher than that of buffered anthocyanins during the storage at 30 degrees C. The current study might be utilized as a model system to predict color properties of anthocyanins in apolar medium.  相似文献   

18.
The aim of the present work was to specify the influence of the polymerization degree on the color stability of anthocyanins using model solutions under higher thermal conditions simulating rapid food aging. Results showed that an increase in polymeric degree improves the color stability of oenin. Solutions containing a catechin tetramer, purified from brown rice, displayed a remarkable stability. Flavanols as monomers, (+)-catechin and (-)-epicatechin, appeared to decrease stability with the formation of a xanthylium salt leading to yellowish solutions. For the dimers, procyanidin B2 and B3, different behaviors on red color stability have been observed corresponding to their different susceptibility to cleavage upon heating. In the presence of the trimeric procyanidin C2, the red color appeared more stable. However, the HPLC chromatograms showed a decrease in the amplitude of the peaks of oenin and procyanidin C2. Concomitantly, a new peak appeared with a maximal absorption in the red region. This newly formed pigment probably came from the condensation of oenin and procyanidin C2.  相似文献   

19.
Fig fruit has been a typical component in the health-promoting Mediterranean diet for millennia. To study the potential health-promoting constituents of fig fruits, six commercial fig varieties differing in color (black, red, yellow, and green) were analyzed for total polyphenols, total flavonoids, antioxidant capacity, and amount and profile of anthocyanins. Using reversed-phase liquid chromatography (RP-LC), various concentrations of anthocyanins but a similar profile was found in all varieties studied. Hydrolysis revealed cyanidin as the major aglycon. Proton and carbon NMR confirmed cyanidin-3-O-rhamnoglucoside (cyanidin-3-O-rutinoside; C3R) as the main anthocyanin in all fruits. Color appearance of fig extract correlated well with total polyphenols, flavonoids, anthocyanins, and antioxidant capacity. Extracts of darker varieties showed higher contents of phytochemicals compared to lighter colored varieties. Fruit skins contributed most of the above phytochemicals and antioxidant activity compared to the fruit pulp. Antioxidant capacity correlated well with the amounts of polyphenols and anthocyanins (R2 = 0.985 and 0.992, respectively). In the dark-colored Mission and the red Brown-Turkey varieties, the anthocyanin fraction contributed 36 and 28% of the total antioxidant capacity, respectively. C3R contributed 92% of the total antioxidant capacity of the anthocyanin fraction. Fruits of the Mission variety contained the highest levels of polyphenols, flavonoids, and anthocyanins and exhibited the highest antioxidant capacity.  相似文献   

20.
为明确彩色油菜花瓣色素成分和色素呈色机制,提高彩色油菜育种效率,本研究比较了红色、橙色、黄色和白色4种色系共10种彩色油菜花瓣色素代谢的次生代谢物含量,并采用液质联用仪(HPLC-MS/MS)分析红色、橙色和黄色油菜花瓣中花青素和类胡萝卜素含量,同时对花青素合成关键酶活性和编码关键酶活性的基因表达量进行分析。结果表明,各色系油菜花瓣积累了大量酚类和类黄酮化合物。红色系和橙色系油菜花瓣中含有丰富的原花青素和花色苷;黄色系油菜花瓣中不含原花青素,但含花色苷;白色系油菜花瓣既不合成原花青素,也不合成花色苷。红色和橙色油菜花瓣中的花色苷主要成分是矢车菊素和芍药素。红色、橙色、黄色和白色油菜花瓣中均含有胡萝卜素和番茄红素,且4种花色花瓣中的番茄红素含量均高于胡萝卜素。红色、橙色和黄色油菜花瓣的番茄红素含量仅为对应花色花瓣花青素的0.25%、0.15%、0.02%。基因表达分析结果表明,引起花青素在不同色系油菜花瓣中积累差异的基因为二氢黄酮醇还原酶基因(DFR)和花青素还原酶基因(ANS),在红色、橙色和橙黄色花瓣中DFR和ANS的表达量分别为黄色花瓣的100倍和1 000倍以上。相关性分析表明,彩色油菜DFR和ANS基因的表达量与花色苷含量呈高度正相关性。但是,DFR和ANS活性在红色、橙色、黄色和白色油菜花瓣中差异不显著。本研究为彩色油菜进行基因操纵中靶基因的选择和合理的育种线路提供了理论基础。  相似文献   

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