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1.
In the European Union, carminic acid and its ammonium, calcium, potassium or sodium salts and its aluminium lakes are approved as food additive E120. In beverages obtained from the German market 4-aminocarminic acid (“acid-stable carmine”) was detected by HPLC–PDA and LC–MS/MS. Isolation of the colorant from a liquid dye preparation used for the production of a beverage sample and subsequent NMR analysis confirmed the presence of 4-aminocarminic acid. Synthesis of 15N-4-aminocarminic acid clearly demonstrated that “acid-stable carmine” is not the ammonium salt of carminic acid, which is approved as food additive in the European Union. In fact, nitrogen in “acid-stable carmine” is covalently bound. The molecular structure of carminic acid is chemically modified and 4-aminocarminic acid does not comply with the specifications laid down for E120 in Commission Regulation (EU) No 231/2012. 4-Aminocarminic acid was also detected in the red-colored glaze of a raspberry cake and in the liquid dye preparation used for coloring this glaze.  相似文献   

2.
A gas chromatography–mass spectrometry method was optimized for quantification of 4-methylimidazole [4-MEI] in balsamic vinegars and processed sauces. The method used ion-pair extraction with bis-2-ethylhexylphosphate and derivatization with isobutylchloroformate, followed by Gas Chromatography-Mass Spectrometry (GC–MS) quantification using 2-ethylimidazole as internal standard. Performance characteristics such as linearity, recovery, and repeatability were good in a broad range of concentrations, and the limit of detection was low enough (130 ug/kg) to detect the presence of small quantities of the compound. A total of 35 samples were analyzed, including balsamic vinegars and processed sauces containing caramel in the ingredients list (soy, Worcestershire, Tonkatsu, Marinara, and Oyster sauces). The presence of 4-MEI was consistent with the presence of ammonia caramel (E150 c and d) in the ingredients list, with average values of 2431 ug/kg for balsamic vinegars and 804 ug/kg for processed sauces. These 4-MEI amounts are almost tenfold higher than those described for caramels containing beverages, which support the necessity to take an effective control on these products.  相似文献   

3.
An analytical method was developed for investigating aminocarminic acid occurrence in E120-labelled red-coloured-beverages and in E120 additives, with the aim of controlling the purity of the carmine additive in countries where the use of aminocarminic acid is forbidden. The carminic acid and the aminocarminic acid were separated by high-performance liquid chromatography–photodiode array–tandem mass spectrography (HPLC-PDA-MS/MS). The method was statistically validated. The regression lines, ranging from 10 to 100?mg/L, showed r2?>?0.9996. Recoveries from 97% to 101% were obtained for the fortification level of 50?mg/L; the relative standard deviations did not exceed 3%. The LODs were below 2?mg/L, whereas the LOQs did not exceed 4?mg/L. The method was successfully applied to 27 samples of commercial E120-labelled red-coloured beverages and E120 additives, collected in Italy during quality control investigations conducted by the Ministry. The results demonstrated that more than 50% of the samples contained aminocarminic acid, evidencing the alarming illicit use of this semi-synthetic carmine acid derivative.  相似文献   

4.
Rate-controlling mechanisms in the photo-degradation of 5-hydroxymethylfurfural (HMF) were studied applying kinetic and thermodynamic compensations. Aqueous solutions of HMF were prepared at a concentration of 100 mg L?1 and at pH values of 3, 3.4, 4, and 5. The UV irradiation of samples was performed in an installation consisting of a black chamber containing the reactor and a mid-pressure mercury lamp with emission wavelengths between 250 and 740 nm. Every sample was irradiated at 12, 25, 35, and 45 °C for 120 min, analyzing their HMF content each 10 min. The photo-degradation data fitted well to zero-order kinetic model, and the constant values were used to study whether the kinetic and thermodynamic compensation could be applied. The isokinetic temperature was very similar for kinetic compensation (TB?=?278.0 K) and thermodynamic compensation (TB?=?277.8 K). Applying the Leffler’s criterion, the HMF photo-degradation was entropically controlled, probably as a consequence of hydrophobic interactions. In order to check the entropical control, two experiments were repeated at pH 3 but avoiding agitation. As the new obtained kinetic constants were highly different from the values previously obtained using agitation, it can be concluded that the HMF photo-degradation is an entropy-controlled process and can be speeded up by changing non-thermal parameters, like agitation.  相似文献   

5.
通过采用探头直径1.4 cm的超声反应器对酸性染料橙G水溶液的降解进行研究。探讨超声反应声强、染料初始浓度、反应pH值以及添加Fe2+对染料脱色的影响。结果表明:Fe2+的加入显著提高了超声反应的脱色率;在pH值2.8,温度30℃,声能密度400 W/L,Fe2+质量浓度1 mg/L条件下,超声反应120 min,30μmol/L染料的脱色率达到92%,COD去除率为42%,该染料的超声降解符合一级反应动力学。  相似文献   

6.
Thermal and storage stabilities of red radish anthocyanins (RRAs) in various juice beverages (apple, grape, peach, pear, pomegranate and lemon) were studied over temperature range 70–90 °C and 4–25 °C. RRAs degradation in all juice beverages followed first-order reaction kinetics. RRAs showed a much faster degradation rate during storage at room temperature (t 1/2 value ≤84.0 days) than did in refrigerated temperature (t 1/2 ≥value 130.9 days). The rate constant (k), E a and Q 10 values for RRAs in juice beverages varied from 1.33 to 0.33, 47.94 to 14.77 kJ mol?1 and 1.16 to 1.89 at 70–90 °C. During heating, RRAs in peach and pomegranate showed higher stability than others at these temperatures. There was a positive correlation (R 2 > 0.9128) between ascorbic acid content of juice beverages (8–36 mg/100 mg) and stability of RRAs at 70–90 °C. It was found that RRAs in apple and pear juice beverage were more stable than in other juice beverages.  相似文献   

7.
为探索高压电场低温等离子体对水中马拉硫磷的降解效能特性,以电压、作用时间及农药初始浓度为试验因素,采用气相色谱测定马拉硫磷的残留并建立降解动力学模型,利用气相串联质谱分析鉴定马拉硫磷降解产物,并结合傅里叶红外光谱研究低温等离子体对马拉硫磷的降解效能,解析其降解途径。结果表明:马拉硫磷在水中的降解效率随着低温等离子体电压强度及作用时间的延长显著增加(P<0.05);在初始浓度为0.1 μg/mL,50 Hz、80 kV处理180 s后,马拉硫磷降解效率达到79.62%±2.97%。马拉硫磷降解趋势符合一级动力学模型,产生的主要中间降解产物为马拉氧磷、磷酸三乙酯、顺-丁烯二酸二乙酯、反-丁烯二酸二乙酯、O,O,S-三甲基二硫代磷酸酯及2-二甲氧基膦硫酰磺基-4-乙氧基-4-氧丁酸。其中毒性较高的马拉氧磷可进一步降解为毒性较低的磷酸三乙酯。马拉硫磷降解过程中中间产物的形成主要经历了P=S键的氧化及C-S键的断裂两种途径。研究为降解水中农药残留研究提供了新的方法参考。  相似文献   

8.
Annatto (Bixa orellana L.) seeds are the source of an orange yellow pigment. The water-soluble annatto dye formulations can be used in beverages, bakery and other food products. An annatto water-soluble dye formulation containing norbixin fraction 22.4 g/L was used in making an orange-ready-to-serve (RTS) beverage model with citric acid and sugar. The orange-RTS beverage was stored at ambient and refrigerated conditions in transparent as well as amber-coloured glass bottles for a period of 5 mo. A dilute solution of the annatto dye formulation (working stock) without addition of citric acid and sugar was also stored under similar conditions. The annatto water-soluble dye formulation and the orange-RTS beverage stored at refrigerated conditions stored well, whereas the losses were very high for the working stock of the formulation irrespective of the storage period/method.  相似文献   

9.
Identification of acid-stable carmine in imported apple syrup product   总被引:1,自引:0,他引:1  
An unknown red pigment was purified from an apple syrup product imported from Canada, using a DIAION HP-20 column with methanol as the eluent. By spectroscopic means and chemical synthesis, the isolated pigment was identified as 4-aminocarminic acid, which is the major pigment of acid-stable carmine (a red colorant illegal in Japan). In addition, HPLC and TLC methods were proposed to detect this illegal colorant. While the color of carminic acid changed from yellow to red in the pH range of McIlvaine buffer (3.0-7.0), the color of 4-aminocarminic acid was always red, and also the ultraviolet/visible (UV/Vis) spectra did not change. These characteristics are useful to distinguish 4-aminocarminic acid from carminic acid.  相似文献   

10.
The mycotoxin tenuazonic acid (TA) was analyzed in different infant foods and beverages including tea infusions (fruit, herbal and fennel tea), puree infant food in jars (complementary food and side dishes) and infant cereals (for preparation of meals after addition of water or milk) by means of a stable isotope dilution assay (SIDA). The median content of TA in infant tea infusions (n = 12) was 2 μg/L, but values up to 20 μg/L were found in fennel tea infusions. In puree infant food in jars (n = 12), the median content of TA was 7 μg/kg, but higher values were detected in products containing tomato (25 μg/kg), banana and cherry (80 μg/kg) and sorghum (20 μg/kg). Infant cereals on the basis of wheat and/or oats, rice, spelt and barley (n = 4) did not contain TA in values higher than 30 μg/kg, but if sorghum was the major ingredient (n = 12), the mean content of TA was 550 μg/kg and the maximum level was 1,200 μg/kg. The European Food Safety Authority (EFSA) evaluated the toxicological potential of TA by following the threshold of toxicological concern (TTC) approach yielding a TTC value of 1,500 ng TA/kg body weight per day. Although long-term studies are needed to enlarge the database on TA contamination of sorghum-based infant food, our preliminary study points out to a tendency that the TTC value may be exceeded by infants consuming predominantly sorghum-based food. Nevertheless, further toxicity data on TA are required with high priority to assess potential health hazards.  相似文献   

11.
《Food chemistry》1999,64(3):423-427
An HPLC method was developed for the simultaneous separation and determination of sugars, ascorbic acid, 5-HMF (5-hydroxymethylfurfural), furfural and four other furanic compounds as the possible degradation products of sugars and ascorbic acid on heating and by Maillard reaction. Sucrose, glucose, fructose, ascorbic acid, dehydroascorbic acid, 5-HMF, furfural, DMHF (2,5-dimethyl-4-hydroxy-3(2H)-furanone), 2-furoic acid, 2-acetylfuran and furfuryl alcohol were separated on an Aminex HPX-87H column (300×7.8 mm). The mobile phase consisted of acetonitrile and 0.005 mol l−1 sulfuric acid aqueous solution (16:84, v/v). Two detectors, a refractive index detector and a photodiode array detector, were used to detect these compounds. Several fruit juice and drink samples were analyzed using this HPLC method. For alcoholic beverages, the content of alcohol was also simultaneously determined by refractive index detector.  相似文献   

12.
In this methodological report, we present a simple, versatile, and reliable procedure for quantitative determination of free and conjugated forms of salicylic acid (SA) in various food products using reversed phase high-performance liquid chromatography (RP-HPLC) with fluorescence detection. The presented sample preparation protocol is considerably simplified in comparison to procedures applied previously and is based on three simple and fast extraction steps providing a supreme tool for large-scale routine assays. The limits of detection were approximately 0.021 μg g?1 of dried weight for spices, lyophilized fruits, or vegetables, and 0.001 μg ml?1 for beverages. The recoveries of the spiked SA were in the range of 87.6 to 96.6 % for all studied products. Applicability of the method was verified by the analysis of salicylate content in a wide range of products including spices (curry, oregano, red pepper), beverages (beer, brewed tea, milk, wine), lyophilized fruits (apricot, strawberry, watermelon), and vegetables (cucumber, tomato).  相似文献   

13.
《Journal of dairy science》2019,102(8):6766-6780
This study describes the effects on glycemic response and the underlying mechanisms of action of increasing the protein concentration and decreasing the casein-to-whey ratio in milk when consumed with a high glycemic breakfast cereal. Twelve healthy men and women, aged 18 to 30 yr and with a body mass index of 20 to 24.9 kg/m2, consumed (in random order) milk beverages (250 mL) containing either 3.1 or 9.3% protein and casein-to-whey ratios of either 80:20 or 40:60. We measured postprandial appetite, glucose, regulatory hormones, and stomach emptying rate over 200 min, as well as food intake at an ad libitum meal at 120 min. Although pre-meal appetite was suppressed to a greater extent with milk beverages that had high (9.3%) compared with regular (3.1%) protein content, food intake was similar among all 4 treatments. Pre-meal mean blood glucose was lower with beverages that had high rather than regular milk protein content, with the lowest glucose peaks after the high milk protein treatment with the 40:60 casein-to-whey ratio. Pre-meal insulin and C-peptide levels were not affected by milk protein content or casein-to-whey ratio, but pre-meal glucagon-like peptide 1 was higher after the treatment containing high milk protein and the 40:60 casein-to-whey ratio, and pre-meal cholecystokinin was higher after the treatments containing high milk protein content. Plasma paracetamol response was also lower after the treatments containing high compared with regular milk protein content. When consumed with carbohydrate, milk beverages with high protein content and (to a lesser extent) a decreased casein-to-whey ratio lowered postprandial glycemia through insulin-independent mechanisms, primarily associated with delayed stomach emptying.  相似文献   

14.
A stability study of octyl methoxycinnamate (OMC) using C-18 HPLC indicated that OMC degraded into a new product when exposed to sunlight. When kept in the dark at 4, 20, 32 and 60 degrees C for one month, no degradation of OMC was detected. Online HPLC-APCI-MS revealed similar APCI mass spectra for OMC and its degradation product. Isolation of the photo-degradation product was done using semi-preparative HPLC. NMR spectra of OMC and the isolated photo-degradation product indicated the change from an E-octyl-p-methoxycinnamate into a Z-octyl-p-methoxycinnamate. NMR spectra of the unfractionated-light-exposed-OMC showed that the Z-OMC was the only product generated.  相似文献   

15.
The stability of the natural sweetener stevioside during different processing and storage conditions as well as the effects of its interaction with water-soluble vitamins, food relevant organic acids and other common low calorie sweeteners and its application in coffee and tea beverages were evaluated. Incubation of the solid sweetener stevioside at elevated temperatures for 1 h showed good stability up to 120°C, whilst at temperatures exceeding 140°C forced decomposition was noticed. In aqueous solutions stevioside is remarkable stable in a pH range 2–10 under thermal treatment up to 80°C, however, under strong acidic conditions (pH 1) a significant decrease in the stevioside concentration was detected. Up to 4 h incubation of stevioside with individual water-soluble vitamins in aqueous solution at 80°C showed no significant changes in regard to stevioside and the B-vitamins, whereas a protective effect of stevioside on the degradation of ascorbic acid was observed resulting in a significant delayed degradation rate. In the presence of other individual low calorie sweeteners practically no interaction was found at room temperature after 4 months incubation in aqueous media. Stability studies of stevioside in solutions of organic acids showed a tendency towards enhanced decomposition of the sweetener at lower pH values depending on the acidic medium. In a stevioside-sweetened coffee and tea beverage, practically, no significant chances neither in caffeine content nor in stevioside content could be noticed. Furthermore an overview of already performed studies in literature about the Stevia-sweetener stevioside and rebaudioside A is given.  相似文献   

16.
Cyanogenic glycosides occur in a wide range of plant species. The potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide, which may result in acute cyanide poisoning and has also been implicated in the aetiology of several chronic diseases. One hundred retail foods were sampled and analysed for the presence of total hydrocyanic acid using an acid hydrolysis–isonicotinic/barbituric acid colourimetric method. Food samples included cassava, bamboo shoots, almonds and almond products, pome fruit products, flaxseed/linseed, stone fruit products, lima beans, and various seeds and miscellaneous products, including taro leaves, passion fruit, spinach and canned stuffed vine leaves. The concentrations of total hydrocyanic acid (the hydrocyanic acid equivalents of all cyanogenic compounds) found were consistent with or lower than concentrations reported in the scientific literature. Linseed/flaxseed contained the highest concentrations of total hydrocyanic acid of any of the analysed foods (91–178 mg kg?1). Linseed-containing breads were found to contain total hydrocyanic acid at concentrations expected from their linseed content, indicating little impact of processing on the total hydrocyanic acid content. Simulation modelling was used to assess the risk due to the total hydrocyanic acid in fruit juice and linseed-containing bread.  相似文献   

17.
张凤清 《食品科学》2010,31(23):380-382
以乙醇提取法获得紫草提取物(Z)和甘草提取物(G),以碱提酸沉法获得槐米提取物(H),再辅以柠檬酸(N)和VE(E),按Z:G:H:N:E 为10:5:5:2:1 的比例复配成复方紫草抗氧化剂(FZK)。以FZK 为受试物,通过小鼠经口急性毒性实验、小鼠骨髓细胞微核实验、小鼠骨髓细胞染色体畸变实验等毒理学实验对FZK 的毒性进行了评价。结果表明:小鼠经口最大耐受剂量均大于16000mg/kg bw,FZK 急性毒性分级为无毒级。剂量小于8000mg/kg bw 条件下,FZK 对小鼠嗜多染红细胞微核率无促提高作用,对小鼠骨髓细胞染色体无致畸作用。该食品添加剂不存在致突变性。  相似文献   

18.
The light-induced degradation of chlorfenapyr under UV was investigated in aqueous solutions containing TiO2 as photocatalyst. The photocatalytic degradation of chlorfenapyr followed pseudo-first-order degradation kinetics (Ct = C0e(-kt)). The study focused on the identification of possible intermediate products during the degradation, using gas chromatography mass-spectrometry (GC-MS) and 1HNMR. Six aromatic intermediates were identified by several techniques during the treatment and some of them were further confirmed by matching authentic standards. Structure analysis of the degradation products suggested two degradation pathways: (1) The aliphatic ether group was cleaved from chlorfenapyr to form pyrrole-alph-carboxylic acid, then the pyrrole group was broken to form 4-chloroglycine; (2) Chlorfenapyr was debrominated and the aliphatic ether group was cleaved from the pyrrole group, which was further broken to form 4-chlorophenylglycine. The glycine was degraded into 4-chlorobenzoic acids, which was further broken into inorganic ions and CO2.  相似文献   

19.
Acidic whey protein beverages are a growing component of the functional food and beverage market. These beverages are also astringent, but astringency is an expected and desirable attribute of many beverages (red wine, tea, coffee) and may not necessarily be a negative attribute of acidic whey protein beverages. The goal of this study was to define the consumer perception of astringency in clear acidic whey protein beverages. Six focus groups (n=49) were held to gain understanding of consumer knowledge of astringency. Consumers were presented with beverages and asked to map them based on astringent mouthfeel and liking. Orthonasal thresholds for whey protein isolate (WPI) in water and flavored model beverages were determined using a 7-series ascending forced choice method. Mouthfeel/basic taste thresholds were determined for WPI in water. Acceptance tests on model beverages were conducted using consumers (n=120) with and without wearing nose clips. Consumers in focus groups were able to identify astringency in beverages. Astringency intensity was not directly related to dislike. The orthonasal threshold for WPI in water was lower (P < 0.05) than the mouthfeel/basic taste threshold of WPI in water. Consumer acceptance of beverages containing WPI was lower (P < 0.05) when consumers were not wearing nose clips compared to acceptance scores of beverages when consumers were wearing nose clips. These results suggest that flavors contributed by WPI in acidic beverages are more objectionable than the astringent mouthfeel and that both flavor and astringency should be the focus of ongoing studies to improve the palatability of these products.  相似文献   

20.
Scope: Juices from Brassicales are mutagenic in Salmonella typhimurium and characteristic adducts are formed with the endogenous DNA in Brassicales homogenates. These effects require myrosinase activity, suggesting an involvement of breakdown products of glucosinolates (GLs). We aimed to identify GLs congeners producing these effects. Methods and results: We investigated twelve individual GLs for mutagenicity in S. typhimurium TA104 and TA100 and for adduct formation with herring sperm DNA using the 32P‐postlabelling/thin‐layer chromatography method. All bacteriotoxic and mutagenic effects observed required the presence of myrosinase. Neoglucobrassicin, 4‐methoxyglucobrassicin and sinalbin showed mutagenicity over wide concentration ranges, with neoglucobrassicin being the most potent congener. Six other GLs led to modest increases in the number of revertants in a small concentration range, before toxicity overshadowed this effect. The remaining three GLs showed some toxicity, but no mutagenicity. However, all twelve GLs formed DNA adducts. Clearly the highest adduct levels were detected with the indole GLs tested. They matched the major adduct spots formed in Brassicales homogenates. Conclusion: The observation that GLs are genotoxic demands follow‐up studies on possible genotoxic and carcinogenic effects of these common food compounds in animal models and humans. Our study may be used to prioritize the congeners in further studies.  相似文献   

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