Caramel Color Research Articles

Rapid determination of 4‐methylimidazole in caramel colours using 1H NMR spectroscopy

AbstractA method utilizing 1H NMR spectroscopy has been developed to measure the concentration of 4‐methylimidazole in caramel colours used as food additive (E150a‐d). For sample preparation, a very simple dilution with water‐ethanol mixture and addition of internal standard is sufficient. 4‐Methylimidazole produces a distinct peak of the methyl group of the molecule in the δ 2.27–2.25 ppm range, where it can be distinguished from other matrix compounds. The method was shown to be of adequate sensitivity with a limit of detection (LOD) of 5.0 mg/L adequate to control the 4‐methylimidazole regulatory limit. The developed method was applied for the analysis of 7 authentic food colourings. Only two products (E150d) contained detectable concentrations of 4‐methylimidazole (662 mg/kg and 401 mg/kg). The NMR method may be used by governmental or industry laboratories for routine control of food colourings.

An Integrated Green Process for Beneficial Utilization of Pulping Black Liquor

An integrated green process was developed to utilize industrial pulping black liquor. The alkali was first recovered by a membrane-electrodialysis device from black liquor. In addition to alkali (NaOH), other by-products reclaimed from pulping black liquor included a watering-emulsifying agent to improve catalytic cracking reaction, viscosity reducer in drilling fluid, rubber coupling agent, and caramel colorant. As a result, compared to pure heavy oil stuff, both catalytic cracking conversion and selectivity of emulsifying heavy oil are improved with the addition of 5 wt% black liquor as a watering-emulsifier. Electrodialysis process carries out until the value of pH for black liquor was 5.0. Then lignin is precipitated with nitric acid, which can be used as a rubber coupling agent to improve the performances of acrylonitile rubber. The remaining liquor (after removing lignin) contains xylan which is used as synthetic material of viscosity reducer for drilling fluid and for production of caramel colorant.

Determination of 2-methylimidazole, 4-methylimidazole and 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole in caramel colours and cola using LC/MS/MS

Substituted imidazoles recently came under scrutiny as they may be indirectly introduced into cola beverages via the use of class IV (E150d) caramel colours and may pose health hazards. A LC/MS/MS method was developed for determining 2- and 4-methylimidazole (2-MI, 4-MI) and 2-acetyl-4-(1,2,3,4)-tetrahydroxybutylimidazole (THI) in beverages and caramel colours. The method is very rapid and easy to conduct as it requires only dilution in eluent for sample preparation. For 4-MI, the recovery was between 94 and 102% for spiked cola samples. The limit of detection was 2μg/L in the measuring solution (corresponding to 40μg/L for cola samples diluted 1:20 during sample preparation). 97 cola samples and 13 caramel colours from Germany and France were analysed. From the 3 analytes, only 4-MI was found in the samples with very varying concentrations (non quantifiable traces to 0.6mg/L in colas and 175-658mg/kg in E150d). The exposure for cola drinkers in worst case scenarios is estimated to be 2-5μg/kg bodyweight/day, which is judged as being only a low risk for public health.

Formation of carcinogenic 4(5)-methylimidazole in caramel model systems: A role of sulphite

Aqueous caramel model systems consisted the d-glucose/NH3/sulphite were heated at 100°C for 2h and amounts of carcinogenic 4(5)-methylimidazole (4-MI) formed were determined. The amount formed ranged from 7.0 to 155.0ppm. A system with 0.1M sulphite yielded the greatest amount of 4-MI, which was 54% more than that yielded from a system without sulphite. When the amount of sulphite increased over 0.1M, the amount of 4-MI reduced. The greatest reduction was achieved with 0.2M sulphite by 68% compared to 0M sulphite, suggesting that sulphite plays an important role in the formation of carcinogenic 4-MI in caramel colour. Also, a system with 0.1M sulphite yielded the most intense caramel colour but the other levels of sulphite did not change the colour intensity significantly. Sulphite contributed slightly to the level of flavour chemicals evaluated using pyrazine formation. The results suggest that sulphite addition at appropriate amount reduces 4-MI formation in caramel colour without sacrificing flavour and colour formation.

Development and sensory profile of a probiotic beverage from apple fermented with Lactobacillus casei

The objective of this study was the development and optimization of a probiotic apple beverage as well as the establishment of a sensory profile by using chemical, microbiological, and quantitative descriptive analysis (sensory profiling). For this purpose, both Lactobacillus casei and L. acidophilus were tested in two different media ‐ Fuji and Gala apple juices ‐ at different pH values. The optimal conditions to develop the apple probiotic beverage were obtained by response surface methodology. They were found to be 10 h of fermentation at 37oC in Gala apple juice. Sensorially, the clarified Gala apple juice was characterized by a caramel color, apple aroma, and an acidic apple taste. The fresh fermented probiotic apple beverage was characterized by a thick texture and sweet taste. The probiotic apple beverage stored for 28 days at 7oC presented a thick texture and acidic taste. Finally, when the fermented probiotic beverage was tested by potential consumers, it presented an acceptance index of 96%.

Qualitative and Quantitative Control of Carbonated Cola Beverages Using 1H NMR Spectroscopy

1H Nuclear magnetic resonance (NMR) spectroscopy (400 MHz) was used in the context of food surveillance to develop a reliable analytical tool to differentiate brands of cola beverages and to quantify selected constituents of the soft drinks. The preparation of the samples required only degassing and addition of 0.1% of TSP in D2O for locking and referencing followed by adjustment of pH to 4.5. The NMR spectra obtained can be considered as “fingerprints” and were analyzed by principal component analysis (PCA). Clusters from colas of the same brand were observed, and significant differences between premium and discount brands were found. The quantification of caffeine, acesulfame-K, aspartame, cyclamate, benzoate, hydroxymethylfurfural (HMF), sulfite ammonia caramel (E 150D), and vanillin was simultaneously possible using external calibration curves and applying TSP as internal standard. Limits of detection for caffeine, aspartame, acesulfame-K, and benzoate were 1.7, 3.5, 0.8, and 1.0 mg/L, respectively. Hence, NMR spectroscopy combined with chemometrics is an efficient tool for simultaneous identification of soft drinks and quantification of selected constituents.

Food caramels: a review.

Caramel, defined as coloring agent and as an antioxidant, is being used in several kinds of food products. It has been classified into 4 classes to satisfy the requirement of several food and beverage systems. The variation in its consistency owing to its basic content of milk solids, sugars, and fat has been studied. Several methods have been found to estimate the amount of color provided by caramel in food products. Various formulations have been cited for the production of caramel by eradicating the frequent areas of problems during its processing. Caramel has been used as a synthetic colorant replacer in the baking and beverage industries. Researchers have aimed to ascertain the contribution to the antioxidant activity of some caramel-containing soft drinks. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an acceptable daily intake (ADI) of Class I caramel color as "not specified"; that of Class II as 0-160mg/kg body weight; that of Class III as 0-200mg/kg body weight; and that of Class IV as 0-200mg/kg body weight. This paper is an overview of the classification, physicochemical nature, formulations, coloring properties, antioxidant properties, and toxicity of caramel in different food systems.

Carcinogenicity and regulation of caramel colorings

2- and 4-methylimidazoles are present as contaminants in caramel colorings manufactured with ammonia catalysts. Both contaminants have been shown to induce cancer in animals and may be present in caramel colorings in amounts that exceed federal guidelines. California requires warning notices on products that could lead to consumption of more than 30 micrograms per day. The US Food and Drug Administration should bar the use of excessively contaminated caramel coloring in food.

Physicochemical, microbiological and sensory characteristics of cashew nut butter made from different kernel grades-quality

This work aimed at evaluating the influence of cashew nut kernel grades and qualities in the characteristics of butter obtained by grinding kernels (89.9 g/100 g) with sugar (8.0 g/100 g), salt (0.1 g/100 g) and soy lecithin (2.0 g/100 g). Kernels and butter were analyzed for physical chemical characteristics (water activity, acid value, pH, moisture, ash, protein and fat contents) and microbiological quality (total and fecal coliforms, Escherichia coli, Salmonella sp., Staphylococcus, mesophilic count, yeast and mold). Minor differences were observed among the different grades and qualities. Nut kernels and corresponding butter showed high nutritive food value containing 18.3–26.9 g/100 g of protein and 35.7–52.6 g/100 g of oil. Fecal coliforms, E. coli, Salmonella sp. or coagulase positive Staphylococcus, were not detected. Sensory acceptability and sensory profile of the butter were also performed. Fourteen sensory descriptors were developed: appearance (caramel color, shiny, visual graininess and visual thickness), aroma (nutty, roasted and rancidity), flavor (nutty, sweet, salty, roasted and rancidity) and texture (consistency and graininess). Although all scores of sensory acceptability were among the acceptance range of the scale, the descriptive analysis found the butter made from B (butts), S (splits) and P (pieces) kernel grades to be of better quality.

Determination of 4(5)-Methylimidazole in Soy Sauce and Other Foods by LC-MS/MS after Solid-Phase Extraction

A method for the determination of 4(5)-methylimidazole (4MeI) in naturally brewed soy sauce was developed for the first time using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). SPE on silica-based reversed-phase cartridges with heptafluorobutyric acid as an ion-pairing reagent was used for the efficient cleanup of 4MeI. A multimode ODS column was employed for the chromatographic separation. To subtract the matrix effect during LC-MS/MS analysis, a standard addition method was used. The levels of 4MeI found in naturally brewed soy sauce were extremely low (ranging from <0.002 to 0.023 μg/g), whereas those in soy sauces containing caramel color were generally high (ranging from 0.43 to 4.8 μg/g). The method proved to be useful for the analysis of 4MeI in other foods such as caramel colors, drinks, and Worcestershire sauce.

Ultrafiltration of caramel color solutions reduces 5-hydroxymethyl-2-furaldehyde

Safety uncertain was always a problem related to the Maillard reaction in heat treatment at a presence of carbohydrate. Early researches have detected caramel color contains 5-hydroxymethyl-2-furaldehyde which is toxic and should be removed from caramel color as much as possible. In the present paper, the effects of ultrafiltration on reducing 5-hydroxymethyl-2-furaldehyde in caramel color solutions were investigated. Results showed that 5-hydroxymethyl-2-furaldehyde could be filtered through 10 kDa cut-off membrane absolutely, while, the retentate's browning intensity was increased significantly. All data show that ultrafiltration is an effective means to reduce 5-hydroxymethyl-2-furaldehyde content and increase browning intensity of caramel color solutions, which might be used in producing healthier caramel colors.

Proposed formation mechanism, antioxidant activity and MDA-MB-231 cells survival analysis of two glucose–ammonium sulfite caramel colour melanoidins fractions

Ultrafiltration and gel chromatography were used to isolate caramel colour melanoidins, and elemental analysis and pyrolysis-GC/MS was used to analyze the characteristic of glucose–ammonium sulfite caramel colour melanoidins of various molecular weights. Results indicated that furfuran was the main skeleton of glucose–ammonium sulfite caramel colour melanoidins. And 5-hydroxymethyl-2-furaldehyde might be one of the origins of melanoidins skeleton which was formed via aldol condensation. A proposed mechanism on the formation of glucose–ammonium sulfite caramel colour melanoidins might be that bi-furan derivatives were formed after aldol condensation (part A), and sulfite ion could connect with carbon atom of formyl group, and amidolinks might be formed between aldehyde of furfuran and nitrogen atoms (part B). At last, parts A and B polymerized and formed the possible structure of the glucose–ammonium sulfite caramel colour melanoidins. And the formed melanoidins have a significant radical-scavenging activity, and complex effects on MDA-MB-231 cells survival.

Toxicology and risk assessment of 5‐Hydroxymethylfurfural in food

5-Hydroxymethylfurfural (5-HMF) as a product of the Maillard reaction is found in many foods. Estimated intakes range between 4 and 30 mg per person and day, while an intake of up to 350 mg can result from, e.g., beverages made from dried plums. In vitro genotoxicity was positive when the metabolic preconditions for the formation of the reactive metabolite 5-sulphoxymethylfurfural were met. However, so far in vivo genotoxicity was negative. Results obtained in short-term model studies for 5-HMF on the induction of neoplastic changes in the intestinal tract were negative or cannot be reliably interpreted as "carcinogenic". In the only long-term carcinogenicity study in rats and mice no tumours or their precursory stages were induced by 5-HMF aside from liver adenomas in female mice, the relevance of which must be viewed as doubtful. Hence, no relevance for humans concerning carcinogenic and genotoxic effects can be derived. The remaining toxic potential is rather low. Various animal experiments reveal that no adverse effect levels are in the range of 80-100 mg/kg body weight and day. Safety margins are generally sufficient. However, 5-HMF exposure resulting from caramel colours used as food additives should be further evaluated.

Effect of bulking agents on the quality of artificially sweetened misti dahi (caramel colored sweetened yoghurt) prepared from reduced fat buffalo milk

Misti dahi, the sweetened variety of dahi, is a popular fermented dairy product of eastern India. It is analogous with sweetened yoghurt, but has pleasant caramel colour and flavour. High sugar content in misti dahi may pose a hurdle for its successful marketing in other parts of the country in the present health foods regime. It is imperative to use a bulking agent when sugar is replaced with artificial sweetener. Hence, the effect of different bulking agents viz. maltodextrin, sorbitol and polydextrose, on the physico-chemical, sensory and textural properties of artificially sweetened misti dahi (ASMD) was studied. Standard method with slight modification was followed for making control misti dahi. ASMD prepared with different bulking agents was examined for sensory quality, physico-chemical properties and texture profile analysis. Maltodextrin increased acidity, water activity and viscosity of ASMD while decreased syneresis compared to other bulking agents. Instrumental surface colour (CIELAB) values of ASMD were similar to control sample. Maltodextrin increased hardness, adhesiveness and gumminess values of ASMD compared to sorbitol and polydextrose. Maltodextrin was found to be the most suitable bulking agent in the preparation of ASMD using aspartame and acesulfame-K.

Quantification of 4-Methylimidazole in Class III and IV Caramel Colors: Validation of a New Method Based on Heart-Cutting Two-Dimensional Liquid Chromatography (LC-LC)

4-Methylimidazole (4MeI) is a nitrogen compound formed during the manufacture of class III and IV caramel colors. The European Commission has limited its content to 250 ppm. Two methods were compared to perform 4MeI quantification in caramels. The first one, currently used and considered to be the reference method, consists of a hot extraction of caramel color with dichloromethane and an analysis of the acetyl derivative of the extract by gas chromatography coupled to mass spectrometry (GC-MS). The second method is based on the heart-cutting two-dimensional liquid chromatography technique (LC-LC) to directly separate 4MeI from the other components present in caramel color sample (diluted in water) in <30 min. The accuracy profile validation method and the comparison between the results obtained with the two methods show that the new and completely automated LC-LC method is usable to quantify 4MeI in caramels.

Scientific Opinion on the re‐evaluation of caramel colours (E 150 a,b,c,d) as food additives

Scientific Opinion on the re‐evaluation of caramel colours (E 150 a,b,c,d) as food additives

Effects of bitterness, roughness, PROP taster status, and fungiform papillae density on bread acceptance

The purpose of this study was to determine how bitterness, roughness, color, perceived 6- n-propylthiouracil (PROP) intensity, and fungiform papillae density affect bread liking. To accomplish this, 78 subjects rated their liking for bread samples that were manipulated to vary independently in bitterness (provided by added wheat germ extract), roughness (provided by added bleached bran), and darkness (provided by added caramel color). The bitterness from added germ extract decreased bread liking. The roughness from the bleached bran increased bread liking; this increase was larger for subjects with higher fungiform papillae densities and was larger for subjects less sensitive to PROP. Added color decreased liking for subjects who preferred refined bread, but it increased liking for subjects who preferred whole wheat bread.

Process Optimization and Consumer Acceptability of Salted Ground Beef Patties Cooked and Held Hot in Flavored Marinade

Food safety is paramount for cooking hamburger. The center must reach 71 °C (or 68 °C for 15 s) to assure destruction of E. coli O157:H7 and other food pathogens. This is difficult to achieve during grilling or frying of thick burgers without overcooking the surface. Thus, the feasibility of partially or completely cooking frozen patties in liquid (93 °C water) together with hot holding in liquid was investigated. Initial studies demonstrated that compared to frying, liquid cooking decreased (P < 0.05) patty diameter (98 compared with 93 mm) and increased (P < 0.05) thickness (18.1 compared with 15.6 mm). Liquid cooked patties had greater weight loss (P < 0.05) immediately after cooking (29 compared with 21%), but reabsorbed moisture and were not different from fried patties after 1 h hot water holding (61 °C). Protein and fat content were not affected by cooking method. However, liquid cooked patties were rated lower (P < 0.05) than fried patties for appearance (5.7 compared with 7.5) and flavor (5.9 compared with 7.5). An 8-member focus group then evaluated methods to improve both appearance and flavor. Salted, grill-marked patties were preferred, and caramel coloring was needed in the marinade to obtain acceptable flavor and color during liquid cooking or hot holding. Patties with 0.75% salt that were grill-marked and then finish-cooked in hot marinade (0.75% salt, 0.3% caramel color) were rated acceptable (P < 0.05) by consumers for up to 4 h hot holding in marinade, with mean hedonic panel ratings > 7.0 (like moderately) for appearance, juiciness, flavor, and texture. Grill-marked and marinade-cooked ground beef patties reached a safe internal cooking temperature without overcooking the surface. Burgers cooked using this method maintained high consumer acceptability right after cooking and for up to 4 h of hot holding. Consumers and foodservice operations could use this method without specialized equipment, and instead use inexpensive and common equipment such as a soup pot or a restaurant steam table. Use of marinades (salt/caramel color or others) in this cooking and holding method provides a nearly endless culinary flavoring opportunity.

Soft drinks consumption and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common clinical condition which is associated with metabolic syndrome in 70% of cases. Inappropriate dietary fat intake, excessive intake of soft drinks, insulin resistance and increased oxidative stress combine to increase free fatty acid delivery to the liver, and increased hepatic triglyceride accumulation contributes to fatty liver. Regular soft drinks have high fructose corn syrup which contains basic sugar building blocks, fructose 55% and glucose 45%. Soft drinks are the leading source of added sugar worldwide, and have been linked to obesity, diabetes, and metabolic syndrome. The consumption of soft drinks can increase the prevalence of NAFLD independently of metabolic syndrome. During regular soft drinks consumption, fat accumulates in the liver by the primary effect of fructose which increases lipogenesis, and in the case of diet soft drinks, by the additional contribution of aspartame sweetener and caramel colorant which are rich in advanced glycation end products that potentially increase insulin resistance and inflammation. This review emphasizes some hard facts about soft drinks, reviews fructose metabolism, and explains how fructose contributes to the development of obesity, diabetes, metabolic syndrome, and NAFLD.

Brachyspira intermedia and Brachyspira pilosicoli Are Commonly Found in Older Laying Flocks in Pennsylvania

Anaerobic intestinal spirochetes (genus Brachyspira) include several species that are recognized as pathogens of poultry. Surveys undertaken in Europe and Australia have shown that layer and breeder flocks are often colonized by the pathogenic species Brachyspira intermedia and Brachyspira pilosicoli, but similar surveys have not been conducted in the United States. In the current study, DNA was extracted from fecal samples (n=50) collected from each of 21 flocks of laying hens >40 wk of age in Pennsylvania, and this material was tested for B. intermedia and B. pilosicoli using a duplex PCR. Negative samples also were tested using a Brachyspira genus-specific PCR. The consistency of the feces was observed, and manure handling systems and medication histories were recorded. Brachyspira intermedia was detected in 662 (63.1%) samples from 17 (81%) flocks, with a within-flock prevalence of 10%-100%. Brachyspira pilosicoli was detected in 112 (10.7%) samples from 5 flocks (23.8%), with a within-flock prevalence of 8%-82%. Four of the flocks had both pathogenic species present, three had no pathogenic species detected, and two had no Brachyspira species detected. Nine flocks had many fecal samples with a wet appearance and/or a caramel color, and all of these were colonized with one or the other of the two pathogenic species. Nine of 12 flocks with manure that was mainly dry also were colonized. Differences in colonization rates between flocks with or without wet manure were not significant. Colonization with pathogenic Brachyspira species, and particularly B. intermedia, occurs very commonly in layer flocks >40 wk of age in Pennsylvania. The significance of this high rate of colonization requires further investigation.