Quantification of 4-Methylimidazole in soft drinks, sauces and vinegars of Greek market using two liquid chromatography techniques

Electrochemical detection of 4(5)-methylimidazole in aqueous solutions

4(5)-methylimidazole (4-MeI) is a potential carcinogen widely used in food colours. EU regulations specify a maximum allowable concentration of 200 ppm for 4-MeI in caramel colours. This study reports an electrochemical determination technique for 4-MeI in caramel colours for the first time. The effect of pH and interference from air were studied to optimize the detection conditions on a glassy carbon electrode in aqueous alkaline solutions using square wave voltammetry (SWV) technique. The concentration of 4-MeI was quantitatively measured down to 10 μM (∼0.8 ppm). Traditional methods such as HPLC, GC, spectrometry and immunoassays involve either expensive instrumentation and reagents or time consuming preparation and detection processes. This study demonstrates the possibility of rapid and simple electrochemical determination of (4-MeI) in food colours with minimum workup using a portable potentiostat.

Isotope dilution-HPLC-MS/MS to investigate the production patterns and possible pathways of free and protein-bound AGEs and 4-MI in cookies

A qualitative and quantitative method for detecting free and protein-bound advanced glycation end products (AGEs) and 4-methylimidazole (4-MI) was established using isotope dilution-HPLC-MS/MS, and successfully applied in cookies and model systems. The effects of different temperatures (160-220 °C) on the formation of free and protein-bound AGEs and 4-MI in cookies were discussed, and the possible model systems (Maillard reaction pathway 1 using wheat gluten protein + glucose + sucrose; direct addition pathway 1 using wheat gluten protein + CML/CEL/4-MI) of protein-bound AGEs and 4-MI were verified. The results showed that the contents of protein-bound CML, CEL, and 4-MI were higher than free content with a tendency of increasing first and subsequently decreasing with temperature, reaching a maximum at 200 °C in cookies. In the model systems, the levels of protein-bound CML, CEL, and 4-MI are higher than those of free CML, CEL, and 4-MI. The protein-bound CML, CEL, and 4-MI accounted for 90.73, 87.64, and 97.56% of the total amount in the model system 1, while accounting for 68.19, 59.00, and 50.96% in the model system 2, respectively. In comparison, protein-bound CML, CEL, and 4-MI could be easily generated directly by Maillard reaction.

Consumption of Sugar-Sweetened Soft Drinks and Risk of Gastrointestinal Cancer: A Systematic Review and Meta-Analysis of Observational Studies

INTRODUCTION

Previous observational studies have reported inconsistent findings on the association between consumption of sugar-sweetened soft drinks (SSSDs) and the risk of gastrointestinal (GI) cancer. This study investigated the associations between SSSD consumption and the risk of GI cancer using a systematic review and meta-analysis.

METHODS

Observational epidemiological studies were searched from the PubMed and EMBASE databases until June 2021. We conducted a meta-analysis of all included studies and subgroup meta-analyses based on various factors.

RESULTS

In a meta-analysis of 27 studies with nine case-control studies and 18 cohort studies, the consumption of SSSDs was modestly associated with an increased risk of GI cancer (odds ratio [OR]/relative risk [RR]: 1.08; 95% confidence interval [CI]: 1.01-1.16), with a significant positive dose-response relationship. In the subgroup meta-analysis by study design, there was a significant positive association between the consumption of SSSDs and GI cancer in cohort studies (RR: 1.11; 95% CI: 1.03-1.20; n = 18), but not in case-control studies. In the subgroup meta-analysis by type of cancer, consumption of SSSDs was significantly associated with an increased risk of colorectal cancer (OR/RR: 1.13; 95% CI: 1.07-1.19).

CONCLUSIONS

This meta-analysis suggests that SSSD consumption significantly increases the risk of GI cancer, specifically colorectal cancer.

4-Methylimidazole, a carcinogenic component in food, amount, methods used for measurement; a systematic review

4-methylimidazole (4-MEI) is widely used industrially. This carcinogenic component has been reported in some types of food. It is usually produced by the caramelization process in food, drinks and caramel coloring. The possible mechanism for the formation of this compound in food is the Maillard reaction. In order to estimate the amount of substance 4-MEI in food, a systematic study was conducted. The selected keywords were 4-methylimidazole, 4-MEI, beverage, drink, meat, milk, and coffee. 144 articles were obtained from the initial search. The articles were evaluated and finally, the data of 15 manuscripts were extracted. Based on the data extracted from selected articles, the highest amount is reported in caramel color, coffee, and cola drinks. In 70% of the selected studies, the analytical method was based on liquid chromatography. In this method, there is no need for derivatization. SPE columns were used to extract samples in most manuscripts. According to per capita consumption, the most exposure to 4-MEI is through coffee. In high risk food products, regular monitoring with analytical methods with high sensitivity is recommended. Furthermore, most of the selected studies were about the validation method, so few samples were selected. It is recommended to design more studies with a high sample size to accurately evaluate this carcinogenic compound in food.

Consumption of artificially sweetened soft drinks and risk of gastrointestinal cancer: a meta-analysis of observational studies

OBJECTIVE

There remain inconclusive findings from previous observational epidemiological studies on whether consumption of artificially sweetened soft drinks (ASSD) increases the risk of gastrointestinal (GI) cancer. We investigated the associations between the consumption of ASSD and the risk of GI cancer using a meta-analysis.

DESIGN

Systematic review and meta-analysis.

SETTING

PubMed and EMBASE were searched using keywords until May 2020 to identify observational epidemiological studies on the association between the consumption of ASSD and the risk of GI cancer.

SUBJECTS

Twenty-one case-control studies and seventeen cohort studies with 12 397 cancer cases and 2 474 452 controls.

RESULTS

In the random-effects meta-analysis of all the studies, consumption of ASSD was not significantly associated with the risk of overall GI cancer (OR/relative risk (RR), 1·02; 95 % CI, 0·92, 1·14). There was no significant association between the consumption of ASSD and the risk of overall GI cancer in the subgroup meta-analyses by study design (case-control studies: OR, 0·95; 95 % CI, 0·82, 1·11; cohort studies: RR, 1·14; 95 % CI, 0·97, 1·33). In the subgroup meta-analysis by type of cancer, consumption of ASSD was significantly associated with the increased risk of liver cancer (OR/RR, 1·28; 95 % CI, 1·03, 1·58).

CONCLUSIONS

The current meta-analysis of observational epidemiological studies suggests that overall, there is no significant association between the consumption of ASSD and the risk of GI cancer.

A Review of the Analytical Methods for the Determination of 4(5)-Methylimidazole in Food Matrices

4(5)-Methylimidazole (4(5)MEI) is a product of the Maillard reaction between sugars and amino acids, which occurs during the thermal processing of foods. This compound is also found in foods with caramel colorants additives. Due to its prevalence in foods and beverages and its potent carcinogenicity, 4(5)MEI has received federal and state regulatory agency attention. The aim of this review is to present the extraction procedures of 4(5)MEI from food matrices and the analytical methods for its determination. Liquid and gas chromatography coupled with mass spectrometry are the techniques most commonly employed to detect 4(5)MEI in food matrices. However, the analysis of 4(5)MEI is challenging due to the high polarity, water solubility, and the absence of chromophores. To overcome this, specialized sample pretreatment and extraction methods have been developed, such as solid-phase extraction and derivatization procedures, increasing the cost and the preparation time of samples. Other analytical methods for the determination of 4(5)MEI, include capillary electrophoresis, paper spray mass spectrometry, micellar electrokinetic chromatography, high-performance cation exchange chromatography, fluorescence-based immunochromatographic assay, and a fluorescent probe.

A U.S. population dietary exposure assessment for 4-methylimidazole (4-MEI) from foods containing caramel colour and from formation of 4-MEI through the thermal treatment of food

4-Methylimidazole (4-MEI) is formed in caramel colours produced using ammonium compounds (Class III and Class IV caramel colours). 4-MEI can also form in food through Maillard reactions between reducing sugars and amino acids during cooking, roasting or dry-heating. The USFDA has analysed over 700 food and beverage samples collected from 2013 to 2015 for the presence of 4-MEI. These samples include foods containing added caramel colour and foods that are not labelled as containing added caramel colour, but which may contain 4-MEI resulting from thermal treatment. The 4-MEI levels in all food samples were quantified using LC-MS/MS. These data were used to develop a comprehensive dietary exposure assessment for 4-MEI for the U.S. population aged 2 years or more and several sub-populations, using two non-consecutive days of food consumption data from the combined 2009-2012 National Health and Nutrition Examination Survey and 10-14-day food consumption survey data for 2009-2012 from the NPD Group, Inc. National Eating Trends-Nutrient Intake Database. Dietary exposure estimates were prepared for each category of foods labelled as containing added caramel colour and of foods not labelled as containing added caramel colour, but which may contain 4-MEI from thermal treatment. Exposure to 4-MEI from consumption of foods containing added caramel colour was higher than that from foods that contain 4-MEI from thermal treatment for all population groups. Cola-type carbonated beverages were the highest contributors for most populations from foods containing added caramel colour. Coffee was the highest contributor for most populations from foods in which 4-MEI could be formed from thermal treatment. An overall combined exposure to 4-MEI was also estimated that included all foods identified as containing added caramel colour and foods in which 4-MEI could be formed by thermal treatment.