HPLC法检测蜜饯中20种合成着色剂含量

建立蜜饯中柠檬黄、新红、苋菜红、靛蓝、丽春红S、胭脂红、喹啉黄、日落黄、诱惑红、亮蓝、酸性红44、酸性红、食品红1、橙黄1、酸性红50、专利蓝V、赤藓红、酸性橙2、酸性橙8、亮蓝G共20种合成着色剂的高效液相色谱测定方法。试样用甲醇/氨水溶液提取,混合型弱阴离子反相固相萃取柱净化,甲醇/20 mmol/L乙酸铵为流动相梯度洗脱,二极管阵列检测器多波长检测,外标法定量。结果表明,该方法在0.1~20 μg/mL的线性范围内相关系数均大于0.999,加标回收率范围为84.0%~104.5%,相对标准偏差（RSD）为1.3%~5.3%。该方法操作便捷、稳定性好、回收率高,适用于蜜饯中20种合成着色剂的同时分析检测。该方法可以扩展应用于其他同结构性质的色素分析,对其他食品类别中色素的检测也具有参考意义。     

Food colorants: anthocyanins

Interest in food colorants as shown by the number of patents has doubled in recent years with natural pigments outnumbering synthetics by five to one. The natural colorant area can be subdivided into anthocyanins, betalains, chlorophylls, carotenoids, flavonoids, polyphenols, Monascus, hemes, quinones, biliproteins, safflower, turmeric, and miscellaneous. All involve different groups of chemical compounds which may be used directly as colorants, or may be chemically modified to produce different hues or increased stability. All usually involve a method of collection, extraction, purification, possibly stabilization, and formulation. A variety of hues can be obtained ranging from green through yellow, orange, red, blue, and violet, depending on the source of colorant. Similarly, water or oil-soluble formulations can be prepared depending on the type of colorant.     

Milk colloidal system as a reaction medium and carrier for the natural blue colorant obtained from the cross-linking between genipin and milk proteins

A promising natural blue colorant was obtained from the cross-linking between genipin and milk proteins. Milk was simultaneously used to extract genipin from the unripe genipap (Genipa americana L.) and evaluated as a reaction medium and carrier for the novel blue colorant. The effects of the milk composition (skimmed, semi-skimmed, and whole) on the kinetic of blue color formation in the colorant-loaded milk samples during their cold storage time for 96 h were evaluated using their color parameters and free-genipin content. The reaction between milk proteins and genipin were evaluated by FTIR spectroscopy. In addition, the blue colorant-loaded milk samples were characterized according to their droplet size distribution, microstructure, and phase separation kinetics. The milk fat content influenced the genipin recovery while the milk with higher protein content contributed to obtaining a more intense blue color. Using whole milk with 3.0 g/100 g fat content favored the light scattering and, thus, a blue colorant with a more intense −b¹ and L¹ values was obtained. On the other hand, the use of skimmed milk with 0.5 g/100 g fat content resulted in more consumption of genipin due to its more protein content for the reaction of blue color compounds formation. Thus, a more intense and darker blue coloration was observed with lower light scattering. The milk composition did not modify the phase separation kinetics of the blue colorant-loaded milk. Therefore, our results have demonstrated that the milk was a suitable medium for the reaction of blue color formation and also a good blue compounds carrier.Industrial relevanceConsumer demands for natural colorants have increased in the last years.Thus, the new food industry challenge is to develop novel healthy, safe and high-quality food products based on natural colorants. Currently, the colorant market does not have still available a natural blue colorant. Therefore, the development of a novel natural blue colorant from plant material could meet this worldwide demand increasing the added value of many products such as ice cream, dairy beverages, and candies.     

Effect of extraction conditions on the quality characteristics of pectin from passion fruit peel (Passiflora edulis f. flavicarpa L.)

Passion fruit (Passiflora edulis f. flavicarpa L.) yellow variety is composed of 50-55 g peel per 100 g of fresh fruit which is discarded as waste during processing. Utilization of passion fruit peel for pectin extraction was studied. Passion fruit peel obtained after juice extraction was blanched in boiling water for 5 min, dehydrated in a cross flow hot air drier at 60 ± 1 °C to a moisture content of 4 g/100 g of dried peel. The dehydrated passion fruit peel was used for extraction experiments of pectin. The effect of pH, peel to extractant ratio, and number of extractions, extraction time and temperature on the yield and quality characteristics of pectin were investigated. The optimized conditions for extraction of pectin from passion fruit peel yielded 14.8 g/100 g of dried peel. Pectin extracted from the dried peels had a methoxyl content of 9.6 g/100 g, galacturonic acid content of 88.2 g/100 g and jelly grade of 200. Extraction of pectin from dried peels of passion fruit may be considered for effective utilization of passion fruit processing waste.     

Determination of Allura red in food samples after cloud point extraction using mixed micelles

A cloud point extraction process using mixed micelles of CTAB, Triton X-114 and Triton X-100 for preconcentration and spectrophotometric determination of trace amounts of Allura red in food samples was developed. The effect of different parameters such as concentration of surfactants, electrolyte concentration, temperature and pH on the cloud point extraction of Allura red was studied in detail and a set of optimum conditions were established. A linear calibration curve in the range of 20–1400 μg/L of Allura red was obtained. Detection limit based on 3S_b was 7.8 μg/L and the relative standard deviation for 75 μg/L of Allura red was 3.87 (n = 10). The method was applied to the determination of Allura red in food samples such as candy, soft drink and jellies.     

Removal of Cr(VI) from aqueous solutions by modified walnut shells

Walnut shell (WNS) (Juglans regia) has been utilised as an adsorbent for the removal of Cr(VI) ions from aqueous solutions after treatment with citric acid. The modification reaction variables, such as citric acid level (5-10 g), reaction time (0-24 h), and temperature (110-130 °C) were studied in batch experiments. The rate of adsorption was studied under a variety of conditions, including initial Cr(VI) concentration (0.1-1.0 mM), amount of adsorbent (0.02-0.20 g), pH (2-9), temperature and contact time (10-240 min). Adsorption of Cr(VI) is in all cases pH-dependent showing a maximum at equilibrium pH values between 2.0 and 3.0 for citric acid modified walnut shell (CA-WNS). The applicability of the Langmuir, Freundlich and D-R adsorption isotherms has been tested for the equilibrium. Maximum adsorption capacities of CA-WNS and untreated WNS under experimental conditions were 0.596 and 0.154 mmol/g for Cr(VI) ions, respectively.     

An optimal extraction solvent and purification adsorbent to produce anthocyanins from black rice (Oryza sativa cv. Heugjinjubyeo)

Black rice was used to produce anthocyanins, an important natural red food colorant. Integrated methods for extraction and purification of anthocyanins were investigated. Four solvents and 6 adsorbents were used for extraction and purification, respectively. Acidified 70%(v/v) ethanol resulted in the highest anthocyanin extract concentration of 461.72 mg/L. Amberlite XAD7HP had the highest adsorption capacity of 0.406±0.010 mg/g of adsorbent and desorption capacity of 0.252±0.016 mg/g of adsorbent. Acidified ethanol effectively eluted anthocyanin pigments from Amberlite XAD7HP at a concentration of 60%(v/v). Experimental adsorption data best fit to pseudosecond-order kinetic and Langmuir isotherm models. Purification parameters were optimized through dynamic adsorption/desorption experiments with Amberlite XAD7HP. The concentration of sugars (impurities) decreased from an initial 452.78 μg/mL to 169.75 μg/mL after purification.     

含铬废革屑对水体中染料的吸附

研究了含铬废革屑对水体中染料的吸附特性。结果表明 :含铬废革屑对酸性染料和直接染料有较大的吸附量 ,但对碱性染料的吸附量却较低。在酸性嫩黄G的最适吸附pH值为 3 .0的条件下 ,酸性嫩黄G的平衡浓度为 82 9mg/L ,其平衡吸附量达到 2 3 4mg/g ;在直接红棕RN的最适吸附 pH值为 9.0的条件下 ,直接红棕RN的平衡浓度为 1 1 5 7mg/L时 ,其平衡吸附量达到 1 5 2mg/g。含铬废革屑对酸性嫩黄G的吸附平衡符合Langmuir方程 ,而对直接红棕RN的吸附平衡符合Freundlich方程。吸附动力学研究表明 :含铬废革屑对以上 2种染料的吸附 ,符合拟二级速度方程。     

Magnetic Mixed Hemimicelles Solid-Phase Extraction of Three Food Colorants from Real Samples

Introducing a specific clean extraction procedure with a minimal matrices effect for food colorant determination is still a challengeable topic and highly recommended. Mixed hemimicelle solid-phase extraction method, based on cetyltrimethylammonium bromide-coated Fe₃O₄/SiO₂ nanoparticles as a novel, simple, and fast preconcentration method, was applied for preconcentration and fast isolation of three synthetic food colorants in foodstuff matrices prior to HPLC-UV-vis determination. The influence of different parameters on extraction efficiency such as surfactant amount, sample pH, time of extraction, desorption condition, and nanoparticles concentration was optimized. Under the optimized conditions, a preconcentration factor of 100 was achieved by extracting 10 mL sample. The limit of detection for the three synthetic food colorants including Tartrazine, Sunset yellow FCF, and Quinoline yellow is 2.50, 1.25, and 2.12 μg/L, respectively. The proposed method was applicable for extraction and preconcentration of three food colorants in various food samples with the food dye contents in the range of 13–105 μg/L.     

Heat and light stability of three natural blue colorants for use in confectionery and beverages

The stabilities of three natural blue colorants—gardenia blue, phycocyanin and indigo—toward heat and light were studied in simple solutions of various pH. Gardenia blue was found to be stable at temperatures up to 80 °C in aqueous solution at pH 3, 5 and 7. Exposure to light of 3×10⁵ lux for 24 hours resulted in approximately 50% degradation of gardenia blue in aqueous solution. Phycocyanin was found to be unstable to heat and light in aqueous solution. Phycocyanin is insoluble in acidic solution (pH 3) and denatures at temperatures above 45 °C at pH 5 and 7, leading to a color change. Exposure to light of 3×10⁵ lux for 24 hours in aqueous solution at pH 5 and 7 caused ~80% degradation. Indigo was found to be stable in medium-chain-triglyceride oil for temperatures up to 90 °C, but to photodegrade (by approximately 70% after five hours of exposure to 3×10⁵ lux), corresponding to a quantum yield of 1.8×10^–4 mol Einstein^–1 for visible light and 1.4×10^–2 mol Einstein^–1 for UV, as determined for monochromatic light of 600 and 313 nm, respectively. Exploratory studies have been carried out with the three blue colorants in application media such as soft drink, jelly gum, hard candy and sugar coating for soft candy. Despite its lower stability towards heat and light, phycocyanin was concluded to be the more versatile blue food colorant among the three studied, showing a bright blue color in jelly gum and coated soft candy.     

Effect of light on growth,intracellular and extracellular pigment production by five pigment-producing filamentous fungi in synthetic medium

The competence of the living creatures to sense and respond to light is well known. The effect of darkness and different color light quality on biomass, extracellular and intracellular pigment yield of five potent pigment producers Monascus purpureus, Isaria farinosa, Emericella nidulans, Fusarium verticillioides and Penicillium purpurogenum, with different color shades such as red, pink, reddish brown and yellow, were investigated. Incubation in total darkness increased the biomass, extracellular and intracellular pigment production in all the fungi. Extracellular red pigment produced by M. purpureus resulted maximum in darkness 36.75 ± 2.1 OD and minimum in white unscreened light 5.90 ± 1.1 OD. Similarly, intracellular red pigment produced by M. purpureus resulted maximum in darkness 18.27 ± 0.9 OD/g and minimum in yellow light 8.03 ± 0.6 OD/g of substrate. The maximum biomass production was also noticed in darkness 2.51 g/L and minimum in yellow light 0.5 g/L of dry weight. In contrast, growth of fungi in green and yellow wavelengths resulted in low biomass and pigment yield. It was found that darkness, (red 780–622 nm, blue 492–455 nm) and white light influenced pigment and biomass yield.     

含铬废革屑负载锆对水中氟的吸附

将锆(IV)负载在含铬废革屑上制备新型氟吸附材料(Zr CrF),并研究了其对水体中氟离子(F-)的吸附特性.结果表明,pH对Zr CrF吸附F-有较大影响,适宜的pH范围为4.0~9.0;当温度为303 K、F-的初始质量浓度为95.0 mg/L、吸附剂用量为1.0 g/L时,Zr CrF对F-的吸附容量为64.1 mg/g,而当吸附剂用量增加到3.0 g/L时,F-的去除率达到99.0%;Zr CrF对F-的吸附等温线符合Freundlich方程,吸附动力学可用拟二级速率方程描述;溶液中共存的SO2-4、NO-3和Cl-基本不影响Zr CrF对F-的吸附,但PO3-4和CO2-3会对吸附产生一定影响.     

Chemiluminescent screening of quenching effects of natural colorants against reactive oxygen species: Evaluation of grape seed,monascus, gardenia and red radish extracts as multi-functional food additives

The quenching effects of commercial available natural colorants against reactive oxygen species (ROS) were investigated. The effectiveness was evaluated by measuring the quenching ratio of chemiluminescence (CL) intensity with each colorant on luminol or methyl-6-(p-methoxyphenyl)-3,7-dihydroimidaz[1,2-a]pyrazin-3-one CL induced by ROS. As a result, the grape seed extracts and polyphenolics dose-dependently quenched CL. The quenching effects of grape seed extract A at 1 mg/ml for superoxide, singlet oxygen, hydroxyl radical, hypochlorite ion and linolenic acid peroxide were 81.1 ± 0.5%, 95.7 ± 0.4%, 99.3 ± 0.3%, 27.7 ± 4.2% and 88.3 ± 1.0%, respectively (n = 3). Except for chalcone, the polyphenolics, such as pelargonidin, cyanidin, delphinidin and trans-resveratrol, also showed the high quenching effects against ROS. These results suggested that the grape seed extract might be useful as a multi-functional food additive.     

废革胶原水刺非织造材料对重金属吸附性能的研究

利用皮革边角料疏解成的废革胶原纤维与高亲水涤纶混合,通过气流成网、水刺缠结等工艺制成的非织造材料可作为一种新型吸附剂,能去除Cu2等重金属离子,有效地应用于环保领域.研究了不同水刺加工参数对废革胶原水刺非织造材料Cu2吸附效果的影响,并从实际生产的印染废水中取样,进行了重金属吸附试验.结果表明:废革胶原水刺非织造材料对...     

Recovery of acetoin from the aqueous solution by means of a novel hyper-cross-linked resin: Equilibrium and kinetics

Acetoin is a high value-added product widely used in the food industry. Recovery of acetoin from the aqueous solution based on a polymeric adsorbent is an efficient method. Hence, a novel hyper-cross-linked resin was prepared and the adsorption behaviors of acetoin on the resin were investigated systematically. The results showed that the maximum adsorption capacity of acetoin onto the resin decreased with increasing temperature, ranged from 192 to 102 mg/g. Batch kinetic experiments revealed that the adsorption process was rapid and the equilibrium was reached in 30 min. The intraparticle diffusion and macropore diffusion models were used to predict the adsorption process. The simulation results showed that the macropore diffusion was the adsorption-rate controlling step. The obtained diffusivity (0.77 × 10⁻⁸ m²/min at the temperature of 293.15 K) had the same magnitude as the acetoin molecular diffusivity, indicating that the mass transfer into the resin pores was occurred by molecular diffusion.     

Inhibitory effect of raspberries on starch digestive enzyme and their antioxidant properties and phenolic composition

Seven primocane fall-bearing raspberry (Rubus idaeus L.) cultivars, Nova (red), Dinkum (red), Heritage (red), Autumn Britten (red), Josephine, Anne (yellow), Fall Gold (yellow) were analysed for potential health promoting properties including their inhibitory effect on starch and fat digestive enzymes, antioxidant activities, and phenolic composition. The tested raspberry extracts showed no detectable inhibition of pancreatic α-amylase and lipase. However, all the extracts exhibited potent inhibition of α-glucosidase with IC₅₀ from 16.8 to 34.2 μg/mL. Four phenolic compounds, ellagic acid, cyanidin-diglucoside, pelargonidin-3-rutinoside, and catechin were identified as the active α-glucosidase inhibitors. The raspberry extracts also possessed significant antioxidant activities with oxygen radical absorbance capacities (ORAC) ranging from 136.7 to 205.2 μmol Trolox equivalents (TE)/g dry weight fruit and DPPH radical scavenging activities from 305 to 351 μmol TE/g. The total phenolic content of raspberry cultivars varied significantly from 40.9 to 98.5 mg of gallic acid equivalents/g dry weight. The anthocyanin content varied widely from 0.1 to 9.5 mg cyanidin 3-glucoside equivalents/g. Nine phenolic acids were quantified in raspberries and their total amounts varied from 157.3 to 713.5 μg/g. The enzyme inhibition and antioxidant properties of raspberry cultivars were not correlated with their total phenolic, anthocyanin, and phenolic acid content. Overall, ‘Dinkum’ and ‘Josephine’ raspberry varieties possess higher total phenolic content, ORAC, DPPH radical scavenging activity, and α-glucosidase inhibitory activity than other five cultivars.     

Synthesis and Characterization of Amino-Terminated Chloration Modified Peanut Shell and Its Application to Preconcentrate and Detect the Concentration of Sunset Yellow in Drink and Jelly Samples

Sunset yellow, as a common pigment, is harmful to people’s health. In this work, a new sensitive adsorbent based on the chlorination peanut shell and HBP-NH₂ was fabricated via one-step synthesis. Optimization of the modified peanut shell was carried out at different temperatures, different molar ratios of reagents, and different time intervals in HBP-NH₂ using Response Surface Methodology (RSM) for the first attempt. The structure of modified peanut shell was characterized by FT-IR, SEM, and TGA analysis. The adsorption properties of the modified peanut shell for Sunset yellow were investigated by batch and column experiments. Batch adsorption’s results suggested that modified peanut shell had a high adsorption capability for Sunset yellow and its maximum saturated adsorption capacity was 468.0 mg/g at 308 K, estimated from the Langmuir model. Furthermore, the modified peanut shell can be eluted easily using 3 mol/L NaOH. The proposed method was successfully applied to quantify the amount of SY in jelly and soft drinks with good recovery valuing from 98 to 104%. Hence, the proposed sensor shows a rapid and sensitive method, low cost, and simple, which is appropriate for alternative technique use for the analysis of food colorants in commercial products.     

The use of photochemiluminescence for the measurement of the integral antioxidant capacity of baobab products

The number of methods to measure antioxidants in botanicals, foods, nutraceuticals and other dietary supplements are increased considerably in the last 10 years. However most techniques require long experimental times and high costs to determine antioxidant capacity of hydrophilic or lipophilic compound in a food mixture. By means of a photochemiluminescence method, we assessed the Integral Antioxidant Capacity (IAC) which represents the sum of the antioxidant capacity of hydrophilic and lipophilic antioxidants. In this study the IAC of extracts from Adansonia digitatata (i.e. red fiber, fruit pulp and leaves), was assessed in comparison to those deriving from other natural sources of antioxidants (i.e. orange, kiwi, apple and strawberry). When compared, IAC values for the examined product resulted as follows: Adansonia digitata red fibre ? Adansonia digitata fruit pulp ? Adansonia digitata fresh leaves ? Adansonia digitata seeds ? Adansonia digitata radix cuticle ? orange fresh pulp ? strawberry fresh fruit pulp > Adansonia digitata radix > bilberry fresh pulp ? kiwi fruit pulp. Results clearly indicate the interesting antioxidants properties of Adansonia digitata red fibre, in particular the IAC value of baobab red fibre was 66 time higher than that of orange pulp, with value of 1617.3 μmol/g and 24.3 μmol/g, respectively.     

Influence of copigment derived from Tasmannia pepper leaf on Davidson's plum anthocyanins

Davidson's plum (Davidsonia pruriens, F. Muell.), a native to Australian rainforests, large, crimson-red fruit, which superficially resembles plum, has been commercially cultivated in Australia since 1990s. The current production volume exceeds market demands therefore this study was designed to evaluate the suitability of Davidson's plum extract as a source of anthocyanin-based food colorant. The stability of the Davidson's plum extract towards heat treatment at 95 °C was higher than that of commercial mulberry colorant, but inferior to colorants derived from red cabbage and purple sweetpotato. An addition of a variety of phenolic acids significantly increased color intensity indicating the formation of copigmentation complexes. Commercial chlorogenic acid as well as extract from a native Australian herb rich in chlorogenic acid, Tasmannia pepper leaf (Tasmannia lanceolata, R. Br.), were both tested in model soft drink solutions subjected to light irradiation and heat treatment. In both cases, the addition of the copigment resulted in a lasting increase in color intensity. In conclusion, Davidson's plum extract can successfully be utilized as a source of natural food color. Extract from Tasmania pepper leaf can be used as a co-pigment for Davidson's plum anthocyanins. PRACTICAL APPLICATION: The color properties of an anthocyanin colorant derived from the native Australian fruit Davidson's plum are comparable to those of mulberry, which is currently applied as a food colorant in Australian food products. Utilization of Davidson's plum fruit as a source of natural color will allow the industry to increase the range of natural pigments and will create new opportunities for the emerging native food industry.     

Recovery of colorants from red prickly pear peels and pulps enhanced by pulsed electric field and ultrasound

The aim of this work was to evaluate the potential of the non-conventional pre-treatments; pulsed electric fields (PEFs) and ultrasounds (USNs), to enhance the extraction of red colorants from red prickly pear (Opuntia stricta Haw.) peels and pulps. The overall goal was to valorize the thick part of the fruit, being discarded for fruit's consumption. PEF and USN treatments were first optimized using fruit slices, followed by a supplementary aqueous extraction (+ SAE) up to 1 h. The optimal conditions were then applied for peels and pulps, separately. Results showed that PEF + SAE and USN + SAE enhanced significantly the extraction of red colorants (betanin/isobetanin), compared to untreated tissues. Promising results for colorants recovery were obtained from fruit peels, using both pre-treatments, compared to that obtained from pulps, and without pre-treatment. Scanning electron microscopy revealed cell denaturation after PEF and USN pre-treatments, which can provide better recovery of the intracellular compounds with less impurity.Industrial relevanceWastes and by-products generated during fruit processing constitute a great source of high-added value compounds, which have the potential to be used as food additives and/or as nutraceuticals. Opuntia fruits constitute a great source of bioactive compounds. In particular, Opuntia fruit processing by-products are interesting as they contain a great amount of potential food additives, including food colorants (i.e. betanin/isobetanin), thus constituting an important alternative to replace synthetic colorants that have been restricted by governmental organizations. In this line, pulsed electric field and ultrasounds are proposed in this work as promising technologies for the enhancement of the extraction of colorants from red prickly pear peels and pulps.