Comparative analyses of copigmentation of cyanidin 3-glucoside and cyanidin 3-sophoroside from red raspberry fruits

Cyanidin 3-glucoside (Cy 3-glu) and cyanidin 3-sophoroside (Cy 3-soph) from red raspberry extracts were selected as pigments, and five phenolic acids as copigments. The influences of pH, temperature, structure of anthocyanins and copigments, and molar ratio of anthocyanins to copigments on the copigmentation effect were analyzed with a UV–Visible spectrophotometer. The reaction was thermodynamically defined in terms of ΔH⁰, ΔG⁰ and ΔS⁰ values.     

Effects of electrode materials on the degradation,spectral characteristics,visual colour,and antioxidant capacity of cyanidin-3-glucoside and cyanidin-3-sophoroside during pulsed electric field (PEF) treatment

The effects of three electrode materials – stainless steel (SS), pure titanium (PT), and titanium-based alloy (TA) – on the PEF-induced degradation, spectral characteristics, visual colour, and antioxidant capacity of cyanidin-3-glucoside (Cy-3-glc) and cyanidin-3-sophoroside (Cy-3-soph) were studied. Cy-3-glc and Cy-3-soph were degraded by PEF; SS retained Cy-3-glc and Cy-3-soph the most, while PT and TA led to greater degradation. Cy-3-glc was more susceptible to PEF than Cy-3-soph. The intensity of UV–Vis spectra absorbance at 520 nm decreased, but it increased at 280 and 325 nm after PEF when using the three electrodes. Their lightness (L^∗) exhibited no changes with SS, but showed a significant reduction with PA and TA. Redness (a^∗) significantly decreased with all three electrodes; the yellowness (b^∗) of Cy-3-glc with PA and TA, and of Cy-3-soph with SS, were also significantly reduced. The antioxidant capacity of Cy-3-glc and Cy-3-soph with SS, in contrast to PT and TA, was enhanced after PEF.     

Kinetic analysis of the degradation and its color change of cyanidin-3-glucoside exposed to pulsed electric field

The degradation and its corresponding color change of cyaniding-3-glucoside (Cy-3-glu) exposed to pulsed electric field (PEF) was investigated in the study. In an aqueous-methanol solution of H₂O (0.5% TFA) and methanol (MeOH) (7:3, v/v), the degradation of Cy-3-glu, which was exposed to PEF at 1.2, 2.2 and 3.3 kV/cm, was increased as the electric field intensity and the treatment time increased (p<0.05), the degradation kinetics was well fitted to a first order reaction. The degradation kinetic constant k _A increased while the half-lives (t _1/2) and decimal reduction time (D values) decreased with an increment of the electric field intensity. PEF had a greater effect on the visual color, lightness L ^* value and redness a ^* value had a slight increase (changing towards the positive direction) while yellowness b ^* value and hue angle H value presented a significant decrease (changing towards the negative direction) (p<0.05), the total color difference (ΔE) showed an increase with an increase of the treatment time and the electric field intensity, the change in b ^* value and H was well fitted to the first-order reaction. Furthermore, a good positive linear correlation between b ^* value and Cy-3-glu content, their regression coefficients were 0.994, 0.999, and 0.997 at 1.2, 2.2, and 3.0 kV/cm, respectively.     

Stability and colour characteristics of PEF-treated cyanidin-3-glucoside during storage

The stability and colour characteristics of PEF (pulsed electric field)-treated cyanidin-3-glucoside (Cy-3-glu) was investigated during storage at 4, 24 and 37 °C. The degradation of Cy-3-glu was analyzed using a first reaction kinetics while its colour characteristics was evaluated using colour indices such as colour density (CD) and CIE L^∗a^∗b^∗ parameters. PEF had no post-effect on the stability and colour characteristics of Cy-3-glu during storage while the storage temperature had a significant effect (p < 0.05). The degradation of PEF-treated Cy-3-glu during storage conformed to the first-order reaction kinetics with regression coefficients R² greater than 0.9300. Corresponding to 4, 24 and 37 °C, the degradation rate constant k in Cy-3-glu significantly increased in the exponential order level of 10⁻⁴, 10⁻³ and 10⁻², while the t_1/2 (the time that 50% Cy-3-glu degradation would take) and D-value (the time that 90% Cy-3-glu degradation would take) of Cy-3-glu during storage decreased in the exponential order level of 10³, 10² and 10. The reduction of CD was closely related to the Cy-3-glu content in this study, the Cy-3-glu content was perfectly predicted using CD with a higher coefficient R² > 0.9999. A significant decrease in b^∗ and H⁰ value was obtained at all storage temperature (p < 0.05). A positive correlation was found between the Cy-3-glu content and b^∗ value or H⁰ value with a coefficients R² > 0.8400 during storage. ΔE increased significantly, ΔE was less than 2 at 4 °C while it was greater than 2 at 24 and 37 °C.     

响应面法优化提取杨梅果渣中矢车菊-3-葡萄糖苷的研究

以杨梅果渣为原料,研究矢车菊-3-葡萄糖苷的提取条件。在单因素实验的基础上,通过Box-Behnken响应面优化杨梅果渣矢车菊-3-葡萄糖苷的提取工艺,得到最佳工艺参数为:乙醇浓度53%,提取温度67℃,提取时间67min。经回归分析表明:回归方程的R2=0.9983,R2Adj=0.9826,预测值为5.32mg/g。经验证,在最佳提取条件下,矢车菊-3-葡萄糖苷的得率为5.25mg/g,回归模型预测值与实测值的相对误差<1%。      

Anti-oxidative analysis,and identification and quantification of anthocyanin pigments in different coloured rice

Anthocyanin pigments in coloured rice cultivars were isolated and identified using high-performance liquid chromatography techniques. Two black rice cultivars (Asamurasaki, Okunomurasaki) contained three major anthocyanins: cyanidin-3-glucoside, peonidin-3-glucoside and malvidin. Chinakuromai (black) rice additionally contained a fourth anthocyanin, petunidin-3-glucoside. Four red rice cultivars contained only malvidin. The total anthocyanin content varied greatly among black rice cultivars (79.5–473.7 mg/100 g), but was lower in red rice (7.9–34.4 mg/100 g). Total phenolic content was similar between red (460.32–725.69 mg/100 g) and black (417.11–687.24 mg/100 g) rice. The oxygen radical absorbing capacity was ranked as follows: red (69.91–130.32 μmol Trolox/g) > black (55.49–64.85 μmol Trolox/g) > green (35.32 μmol Trolox/g) > white (21.81 μmol Trolox/g) rice. The antioxidant capacity resulted mainly from the seed capsule, not the endosperm. The anthocyanin pigments contributed little to the total antioxidant capacity of red (0.03–0.1%) and black (0.5–2.5%) rice cultivars. Hence, the antioxidant capacity is derived mainly from other phenolic compounds.     

Effects of pectolytic enzyme treatments on anthocyanins in raspberry juice

Raspberry juices treated with two commercial pectinase preparations lost almost 20% of their total anthocyanin pigments; losses were related to both concentration of enzyme and time of treatment. Analysis of individual anthocyanins showed differences between the enzymes. Ultrazyme reduced all components in similar proportions, whereas Pectinex apparently also converted cyanidin-3-sophoroside and cyanidin-3-glucosylrutinoside into cyanidin-3-glucoside and cyanidin-3-rutinoside respectively, presumably by hydrolysis of β1–2 glucosidic bonds by glucosidase present in the Pectinex.     

Thermal characterization of the anthocyanins from black soybean (Glycine max L.) exposed to thermogravimetry

One anthocyanin compound, cyanin-3-glucoside, was isolated and identified by high performance liquid chromatography tandem mass spectrometry (HPLC_MS/MS) from seed coat of black soybean variety, Heizi to assess its thermal characterization in vitro. The thermal characterization of anthocyanin was studied by thermogravimetry (TG) analysis. The results from the TG curves showed the decomposition of anthocyanin occurred in three stages. Glucose cleaved from the cyanin-3-glucoside occurred in the first stage. Degradation of cyanin and small amounts of cyanin-3-glucoside appeared mainly in the second stage. The sugar in the anthocyanin was decomposed in the third stage. Thermodynamic analysis was applied by free dynamic model. TG-isothermal experiments for the anthocyanins from black soybean seed coats confirmed the correct of the thermodynamic analysis.     

黑米矢车菊素-3-O-葡萄糖苷及其月桂酸酰化物对小鼠肠道免疫功能的影响

目的 本文研究了黑米矢车菊素-3-O-葡萄糖苷（Cyanidin-3-O-glucoside, C3G）及其与月桂酸的酰化产物（cyanidin-3-glucoside lauryl ester, L-C3G）对小鼠肠道免疫功能的影响。方法 首先,以小鼠为试验动物,经过低、中及高剂量的C3G和L-C3G灌胃28 d后,测定小鼠的体重、肠道消化酶活性（蛋白酶、淀粉酶、脂肪酶）、肠道pH、肠道组织形态及免疫细胞数量等指标,对C3G和L-C3G的肠道免疫作用进行评价。结果 与空白对照组相比,C3G和L-C3G能够降低小鼠的体重和小鼠肠道pH;提高淀粉酶和蛋白酶活性,降低脂肪酶活性;提高小鼠肠腔绒毛高度,降低隐窝深度,提高消化能力;提高肠道免疫细胞（T细胞、肥大细胞、杯状细胞）的数量。此外,与C3G相比,L-C3G有更强的免疫促进作用。结论 C3G和L-C3G有较好的肠道免疫促进作用。     

Copigmentation between malvidin-3-glucoside and some wine constituents and its importance to colour expression in red wine

Thermodynamic parameters for intermolecular copigmentation interactions involving malvidin-3-glucoside were determined by UV/visible spectroscopy at wine pH (pH 3.6). These included association constants, enthalpy and entropy changes, which were measured for chlorogenic acid, caffeic acid, quercetin, quercetin-3-glucoside, (−)-epicatechin, (+)-catechin, procyanidin dimer and seed tannin. Quercetin produced the strongest copigment (K_CP = 2900 ± 1300), whilst the addition of glucose at position 3 (quercetin-3-glucoside) reduced its effect by almost 10-fold. Malvidin-3-glucoside self-association (K_D = 3300 ± 300 mol⁻¹ l) was thermodynamically favoured over intermolecular interaction with any of the copigments tested. No colour enhancement due to self-association was observed for malvidin-3-glucoside-derived pigments that cannot enter hydration reactions. In addition, malvidin-3-(6-O-p-coumaryl)glucoside did not show colour enhancement suggesting that the p-coumaryl group prevents self-association. The malvidin-3-glucoside circular dichroism (CD) spectrum was not affected by indicated changes in malvidin-3-glucoside concentration. These observations demonstrate that self-association of malvidin-3-glucoside is more important than copigmentation in young red wine.     

Stability of DON and DON-3-glucoside during baking as affected by the presence of food additives

The mycotoxin deoxynivalenol (DON) is one of the most common mycotoxins of cereals worldwide, and its occurrence has been widely reported in raw wheat. The free mycotoxin form is not the only route of exposure; modified forms can also be present in cereal products. Deoxynivalenol-3-glucoside (DON-3-glucoside) is a common DON plant conjugate. The mycotoxin concentration could be affected by food processing; here, we studied the stability of DON and DON-3-glucoside during baking of small doughs made from white wheat flour and other ingredients. A range of common food additives and ingredients were added to assess possible interference: ascorbic acid (E300), citric acid (E330), sorbic acid (E200), calcium propionate (E282), lecithin (E322), diacetyltartaric acid esters of fatty acid mono- and diglycerides (E472a), calcium phosphate (E341), disodium diphosphate (E450i), xanthan gum (E415), polydextrose (E1200), sorbitol (E420i), sodium bicarbonate (E500i), wheat gluten and malt flour. The DON content was reduced by 40%, and the DON-3-glucoside concentration increased by >100%, after baking for 20 min at 180°C. This confirmed that DON and DON-3-glucoside concentrations can vary during heating, and DON-3-glucoside could even increase after baking. However, DON and DON-3-glucoside are not affected significantly by the presence of the food additives tested.     

Isolation and identification of pelargonidin 3-glucoside in mangosteen pericarp

In the present study, we have identified pelargonidin 3-glucoside, along with two known anthocyanin; cyanidin 3-sophoroside and cyanidin 3-glucoside, from acidified, methanolic extract of mangosteen pericarp. The compounds were separated by preparative HPLC after purification by partition against ethyl acetate and Amberlite XAD-7. The structures of the compounds were confirmed by high performance liquid chromatography (HPLC), UV–Vis absorption spectra, high-resolution electrospray mass spectrometry and 1D, 2D nuclear magnetic resonance (NMR) spectroscopy. This new pigment family adds to the growing body of data supporting the use of natural colourants in food. Cyanidin 3-sophoroside was the major anthocyanin detected in large amount (76.1%), followed by cyanidin 3-glucoside (13.4%) and pelargonidin 3-glucoside (6.2%).     

Isolation and characterization of mutatoxanthin-epimers from red paprika (Capsicum annuum)

 (3S,5R,8R,3′R)- and (3S,5R,8S,3′R)-mutatoxanthin were isolated from red spice paprika (Capsicum annuum) and characterized by their UV-VIS, CD, ¹H-NMR, ¹³C-NMR and mass spectra. Received: 22 November 1999 / Revised version: 11 February 2000     

Products of Thermal Degradation of the Anthocyanins Cyanidin-3-glucoside,Cyanidin-3-rutinoside and Cyanidin-3-sophoroside

During thermal degradation of anthocyanins, cyanidin-3-glucoside, cyanidin-3-rutinoside, cyanidin-3-sophoroside, at 98 °C in model systems of pH = 1, 2.5 3.5 and 4.5, seven compounds were isolated by means of paper chromatography. Among them quercetin, phloroglucin-aldehyde and protocatechuic acid were identified.     

纳豆菌的分离鉴定及其抗菌活性

本研究从日本纳豆分离获得抗菌活性高的纳豆菌，对其进行了菌种鉴定；考察了其对常见的食品污染菌（细菌、酵母菌和霉菌）的拮抗作用，并与常见的食品防腐剂的抗菌作用进行了比较，而且，考察了纳豆菌抗菌作用的遗传稳定性。     

利用中压制备液相色谱从桑葚中快速制备矢车菊素-3-葡萄糖苷单体

单体花色苷的快速大量制备长久以来是花色苷产业化中的难题,而中压制备液相色谱在产业应用中有着很大的开发空间。选取花色苷组分较单一的桑葚为实验原料,经提取分离总花色苷后使用填装有反相C18填料的耐压玻璃柱作为中压制备液相色谱柱,纯化制备矢车菊素-3-葡萄糖苷单体。结果显示：3 个色谱分离峰中目的峰（峰2）经高效液相色谱和质谱确证为由矢车菊素-3-葡萄糖苷（cyanidin-3-glucoside,C3G）和矢车菊素-3-芸香糖苷（cyanidin-3-rutinoside,C3R）组成,采用峰面积归一化法计算得到C3G纯度为73.56%;通过对峰2采用切割方式进行收集,C3G纯度达到98%以上,单次收集到C3G单体溶液650?mL。中压制备液相色谱法单次上样量大、步骤简洁、成本低廉,可为矢车菊素-3-葡萄糖苷单体的规模化生产提供一定的参考。     

Identification of degradation pathways and products of cyanidin-3-sophoroside exposed to pulsed electric field

Pulsed electric field (PEF) can induce the degradation of anthocyanins. In this study, the degradation products and postulated degradation mechanism and pathways of cyanidin-3-sophoroside (Cy-3-soph) by PEF were investigated using a combination of UV–vis spectra and HPLC-MS. Four isomers of quinonoid benzoyloxyphenylacetic acid esters resulting from the oxidative degradation of Cy-3-soph at pH 1.5 and 3.5 were detected in a model solution after PEF. The prevailing degradation pathway was different from thermal degradation. Cy-3-soph was degraded through a Baeyer–Villiger oxidation by the nucleophilic attack of hydrogen peroxide and then further oxidised by other oxidants, such as the hydroxyl free radical induced by the electrochemical reactions during PEF treatment. The thermal degradation pathways at pH 1.5 and 3.5 were also involved in the degradation of Cy-3-soph during PEF treatment.     

对引进乳酸菌胶囊菌种的分离、鉴定和某些生长特性的研究

对引进的乳酸菌胶囊中的菌种进行了分离和纯化，经形态和生理生化检测，鉴定为肠球菌族、兰斯斐尔德Ｄ族、粪肠球菌［１］，对该菌的某些生长特性进行了研究，结果表明，其生长的最适培养温度为３７℃，最适ｐＨ值范围为７．０～９．０，耐牛胆汁盐浓度为４０％。     

Interaction between Cyanidin 3-glucoside and Cu(II) ions

The interaction between cyanidin 3-glucoside (Cy 3-glc) and Cu(II) in a binary solvent (methanol–water, 1:1, (v/v)) and in a phosphate buffer was studied. It is demonstrated that Cy 3-glc and Cu(II) ions form a complex that is manifested by appearance of a new absorption band. In the complex, the reduction of Cu(II)–Cu(I) and oxidation of Cy 3-glc takes place. The association constant of the complex formation was calculated using the Rose–Drago method. The complex stoichiometry in the binary solvent was 1:1, and the association constant was K = (28,600 ± 2600) M⁻¹. Interaction of Cy 3-glc and Cu(II) ions has two stages “fast” and “slow”. The kinetics of these processes has been investigated. Thermodynamic data for the “fast” process: enthalpy (ΔH^∗) and entropy (ΔE^∗) of activation, were calculated.