Mitigation strategies for ester bound 2-/3-MCPD and esterified glycidol in pre-fried breaded and frozen fish products

Determination of glycidyl fatty acid esters in edible vegetable oils by HPLC-ESI-QQQ-MS/MS combined with cryo-degreasing tandem dispersive solid-phase extraction

Glycidyl fatty acid esters (GEs) have been identified as food contaminants that can form during the processing and heating of edible oils. Their widespread occurrence raises potential concerns for consumers. This study aimed to develop a simple and effective analytical method for molecular recognition using mass spectrometry fragmentation patterns. Furthermore, it sought to simultaneously and quantitatively determine five common GEs in highly complex fatty matrices (oils) using high-performance liquid chromatography-triple quadrupole tandem mass spectrometry (HPLC-ESI-QQQ-MS/MS). An extraction method using acetonitrile was used, and the purification of the extract was optimized using cryo-degreasing-tandem dispersive solid-phase extraction (d-SPE) to eliminate fatty interferents. The method validation yielded recoveries ranging from 81.17% to 109.28% and the method precision was < 10.00%. The limits of quantification ranged from 0.08 to 0.21 ng/g, which is below the current legal limits. This approach may play a crucial role in ensuring food safety.

Effects of Endogenous Antioxidants in Camellia Oil on the Formation of 2-Monochloropropane-1, 3-diol Esters and 3-Monochloropropane-1,2-diol Esters during Thermal Processing

2-Monochloropropane-1, 3-diol (2-MCPD) esters and 3-monochloropropane-1,2-diol (3-MCPD) esters, a class of substances potentially harmful to human health, are usually formed during the refining of vegetable oils under high temperature. The effects of endogenous antioxidants in vegetable oils on the formation of 2- and 3-MCPD esters is still unknown. In this study, the effects of endogenous antioxidants (α-tocopherol, stigmasterol and squalene) on the formation of 2- and 3-MCPD esters in model thermal processing of camellia oil were investigated. The possible formation mechanism of 2- and 3-MCPD esters was also studied through the monitoring of acyloxonium ions, the intermediate ions of 2- and 3-MCPD esters formation, and free radicals by employing infrared spectra and electron paramagnetic resonance (EPR), respectively. The results indicated that the addition of α-tocopherol had either promoting or inhibiting effects on the formation of 2- and 3-MCPD esters, depending on the amount added. Stigmasterol inhibited the formation of 3-MCPD ester and 2-MCPD ester at low concentrations, while promoting their formation at high concentrations. Squalene exhibited a promotional effect on the formation of 3-MCPD ester and 2-MCPD ester, with an increased promotion effect as the amount of squalene added increased. The EPR results suggested that CCl3•, Lipid alkoxyl, N3• and SO3• formed during the processing of camellia oil, which may further mediate the formation of chlorpropanol esters. This study also inferred that squalene promotes the participation of the free radical in chlorpropanol ester formation.

Association between dietary 3-monochloropropane-1,2-diol esters (3-MCPDE) and renal cancer in Peninsular Malaysia: exposure assessment and matched case-control study

3-Monochloropropane-1,2-diol esters (3-MCPDE) are food contaminants commonly found in refined vegetable oils and fats, which have possible carcinogenic implications in humans. To investigate this clinically, we conducted an occurrence level analysis on eight categories of retail and cooked food commonly consumed in Malaysia. This was used to estimate the daily exposure level, through a questionnaire-based case-control study involving 77 subjects with renal cancer, with 80 matching controls. Adjusted Odds Ratio (AOR) was calculated using the multiple logistic regression model adjusted for confounding factors. A pooled estimate of total 3-MCPDE intake per day was compared between both groups, to assess exposure and disease outcome. Among the food categories analysed, vegetable fats and oils recorded the highest occurrence levels (mean: 1.91 ± 1.90 mg/kg), significantly more than all other food categories (p < .05). Risk estimation found the Chinese ethnic group to be five times more likely to develop renal cancer compared to Malays (AOR = 5.15, p = .001). However, an inverse association was observed as the 3-MCPDE exposure among the Malays (median: 0.162 ± 0.229 mg/day/person) were found to be significantly higher than the Chinese (p = .001). There was no significant difference (p = .405) in 3-MCPDE intake between the cases (median: 0.115 ± 0.137 mg/day/person) and controls (median: 0.105 ± 0.151 mg/day/person), with no association between high intake of 3-MCPDE and the development of renal cancer (OR = 1.41, 95% CI: 0.5091-2.5553). Thus, there was insufficient clinical evidence to suggest that this contaminant contributes to the development of renal malignancies in humans through dietary consumption. Further research is necessary to support these findings, which could have significant public health ramifications for the improvement of dietary practices and food safety measures.

The Formation of 3-Monochloropropanediol Esters and Glycidyl Esters during Heat-Induced Processing Using an Olive-Based Edible Oil

With the prevalence of edible diacylglycerol (DAG) oil, which is beneficial to human, the generation of 3-monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) as well as the stability of physical properties during heat-induced processing still need to be explored. In this study, the experiment used olive-based edible oil with different contents of DAG (40, 60, and 80%) to make crackers and fry chicken. They were heated at 160 and 180 °C to determine the changes in 3-MCPDE and GE, the crackers’ hardness and gumminess, and the physical properties of the oil. During baking and frying, 3-MCPDE decreased, while the content of GE slightly increased with the prolonged heating duration. Finally, 3-MCPDE and GE were lower than 1.25 mg/kg and 1.00 mg/kg, respectively. The AV increased proportionally as duration increased and POV was below 0.30 g/100 g. In general, the changes in 3-MCPDE and GE were related to the heating temperature and duration, and not significantly (p > 0.05) related to the content of DAG.

Household cooking oil type and risk of oral micronucleus frequency in Chinese nonsmokers

Household animal fat has been linked to increased incidence of cancers compared with vegetable fat. However, few epidemiological studies have associated these two cooking oil types with precancerous genotoxic effects, such as occurrence of micronuclei (MN). This study aimed to explore the association between oral MN frequency and household cooking oil type and whether the association can be attributed to polycyclic aromatic hydrocarbons (PAHs). We collected information about individual cooking oil use, measured genotoxic effects by MN tests and urinary PAHs metabolites (OHPAHs) in 245 nonsmokers. The associations between household cooking oil type and MN frequency and OHPAHs were analyzed using generalized linear models (GLMs) and logistic regression models, evaluating odds ratios and coefficient (95% confidence intervals) (ORs, 95% Cls; β, 95% Cls). The odds of animal fat consumers, rather than vegetable fat consumers, was positively associated with higher MN frequency (OR = 1.94, P < 0.05). The associations were discovered in participants only using kitchen ventilation (OR = 2.04, P < 0.05). Animal fat consumers had higher total OHPAHs than vegetable fat consumers (1.58 ± 0.22 mg/mol, Cr vs 1.20 ± 0.12 mg/mol, Cr; P = 0.028). Significant correlations were observed between total OHPAHs quartiles and increased MN frequency (β = 0.38, P-trend = 0.026). After stratifying by household cooking oil type, sensitivity analyses showed that the positive association between total OHPAHs quartiles and increased MN frequency was only observed in animal fat consumers (β = 0.61, P-trend = 0.030). In conclusion, usage of household animal fat was associated with an increased odds of oral MN frequency in Chinese nonsmokers and the odds correlated with increased PAHs exposure. This finding supplemented evidence associating cooking oil type with genotoxic effects and explained its association with PAHs exposure.

Effects of Food Types, Frying Frequency, and Frying Temperature on 3-Monochloropropane-1,2-diol Esters and Glycidyl Esters Content in Palm Oil during Frying

3-Monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) have high toxicity and have drawn global attention because of their widespread occurrence in refined oils and oil-based foods. In this study, the effects of food type (potato chips and chicken breasts), frying frequency, and frying temperature on the formation of 3-MCPDE and GE in palm oil (PO) were investigated. The results showed that 3-MCPDE was formed easier in chicken breasts than potato chips. The GE content decreased in PO after it was used for frying potato chips and chicken breasts with or without NaCl. Frying frequency was an influencing factor in the formation of 3-MCPDE and the decrease in GE in PO. Frying temperature was positively correlated with GE degradation, while it had a bidirectional effect on the formation of 3-MCPDE. The formation kinetic equations indicated that 3-MCPDE and GE followed zero-order reactions in PO. The estimated activation energy (Ea) of 1,2-bis-palmitoyl-3-chloropropanediol (Pa-Pa, 41.05 kJ/mol) was lower than those of the other three types of 3-MCPDE; this is the first theoretical explanation for why PO contains more 3-MCPD than other edible oils. Among GEs, glycidyl oleate (Li-GE) was degraded more readily than other GEs.

Free and bound MCPD and glycidyl esters in smoked and thermally treated fishery products of the German market

To provide a comprehensive overview of the amounts of unesterified and bound 2- and 3-monochloropropanediol (MCPD) and glycidyl esters (G–E) in processed fishery products sold in Germany, an analysis of various frequently consumed products was conducted. In total, 258 commercial samples of breaded and pre-fried fishery products (e.g., frozen fish fingers), fried fish products (e.g., products in marinade), canned fish, smoked fish and some smoked spice preparations were examined. In addition, the effect of different kitchen preparation methods (e.g., baking, frying and roasting) on the MCPD and G–E amounts of fish fingers was studied. The mentioned process contaminants, MCPD and G-E, were quantifiable in the majority of the samples. Although pre-fried and fried fishery products predominantly contained MCPD esters (MCPD-E), mainly free MCPD was found in smoked fish. Compared with other types of smoke generation, hot smoked fish prepared in traditional Altona smoking kilns contained, on average, the highest 3-MCPD contents (range: 12–246 µg/kg). The amounts of bound MCPD in the fried fish products (range for 3-MCPD-E: < LOQ-808 µg/kg) were not significantly different from the amounts in the investigated pre-fried fish samples (range for 3-MCPD-E: < LOQ-792 µg/kg). However, they differ significantly from the amounts in unfried products (< LOQ). After preparation in the kitchen, the contents in the ready-to-eat fish fingers depend primarily on the initial contaminant amounts of the frozen product and/or the frying oil, respectively.

The occurrence of 3-monochloropropane-1,2-diol esters and glycidyl esters in vegetable oils during frying

3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) are processed-developed contaminants presence in vegetable oils after undergo refining process under excessive heat. Refined oils are extensively used in various frying applications, nevertheless, the reservation against their quality and safety aspects are of major concern to consumers and food industry. Realizing the importance to address these issues, this article deliberates an overview of published studies on the manifestation of 3-MCPDE and GE when vegetable oils undergo for frying process. With the modest number of published frying research associated to 3-MCPDE and GE, we confined our review from the perspectives of frying conditions, product properties, antioxidants and additives, pre-frying treatments and frying oil management. Simplicity of the frying process is often denied by the complexity of reactions occurred between oil and food which led to the development of unwanted contaminants. The behavior of 3-MCPDE and GE is closely related to physico-chemical characteristics of oils during frying. As such, relationships between 3-MCPDE and/or GE with frying quality indices - i.e. acidity in term of free fatty acid or acid value); secondary oxidation in term of p-anisidine value, total polar compounds and its fractions, and refractive index - were also discussed when oils were subjected under intermittent and continuous frying conditions.

Current Progresses on Monochloropropane Diol Esters in 2018-2019 and Their Future Research Trends

The fatty acid esters of monochloropropane diol (MCPD) are a group of food source contaminants formed during thermal processing. These components were recognized as potential food source toxicants in the past few decades, and growing evidence has proven their toxic effects, especially to kidneys and testes. Therefore, increasing research articles reported their results about MCPD esters in recent years. In this perspective, a total of 35 research articles/reviews about MCPD esters, including the studies concerning the analytical methods, occurrences, toxicity, formation mechanism, and mitigation strategies of MCPD esters in 2018-2019 have been summarized and discussed. Updating the latest research results about MCPD esters could improve our understandings about these components, especially on the toxic effects and the mitigation approaches in both academia and industry.

Effect of Anti-Clouding Agent on the Fate of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Palm Olein during Repeated Frying

Issues on 3-monochloropropane-diol-1,2-diol (MCPD) esters and glycidyl esters in refined oil have gained much attention when these heat-induced contaminants are associated with health implications. Oil that undergoes the frying process could influence the fates of 3-MCPD esters and glycidyl esters, especially with the addition of an anti-clouding agent. In this study, we investigated the effect of polyglycerol fatty acid esters (PGE) on the transients of 3-MCPD esters and glycidyl esters in palm olein (POo) during intermittent frying. Thermal resistance of POo fortified with PGE (0.1% to 0.4%) was assessed for 8 h of daily frying operations at 180 °C across five consecutive days. The addition of PGE decelerated the reduction of 3-MCPD esters and glycidyl esters with the progression of frying. The presence of these compounds coincided with the amount of oil taken up by the fried product. The inclusion of PGE in POo also induced higher augmentation of polar compound fractions, i.e., oxidised triacylglycerols (OxTAG) and polymerised triacylglycerols (PTAG), but gave comparable free fatty acid (FFA), p-anisidine value (AnV), total chloride and fatty acid composition (FAC) with control oil (POo). The results also showed that the presence of chloride in POo did not onset further formation of 3-MCPD esters and glycidyl esters throughout the frying period. As the behaviours of 3-MCPD esters and glycidyl esters were affected by PGE, only a sufficient amount should be added into POo to ensure oil clarity at a realistic period.

Fatty Acid Esters of 3-Monochloropropanediol: A Review

Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD esters) are a new group of processing-induced chemical toxicants with possible nephrotoxicity and testicular toxicity. 3-MCPD esters have been detected in many food categories, including refined edible oils, bread, coffee, and infant formula. 3-MCPD esters have also been detected in human breast milk, indicating their possible absorption and distribution in human organs and tissues. 3-MCPD esters have become a food safety concern, and in 2013 the European Food Safety Authority estimated a tolerable daily value (TDI) of 2 μg/kg body weight (BW) for the amount of free 3-MCPD. This review summarizes the available information on 3-MCPD ester research, including the analytical methods, exposure biomarkers, absorption and metabolism, toxicities, formation mechanisms, and mitigation strategies as well as the occurrence of 3-MCPD esters in human foods. This review may serve as a scientific foundation for advancing our understanding of 3-MCPD esters and their food safety concerns.

Effect of chloride on the formation of 3-monochloro-1,2-propanediol fatty acid diesters and glycidol fatty acid esters in fish, meats and acylglycerols during heating

The effects of the presence of chloride on the formation of 3-monochloro-1,2-propanediol fatty acid esters (3-MCPDEs) and glycidol fatty acid esters (GEs) in saltwater fish, meats and acylglycerols (diacylglycerol and triacylglycerol) during heating were investigated in this study. Five saltwater fish species (salmon, saury, yellowtail, mackerel and Spanish mackerel) were grilled with a fish griller. 3-MCPDEs and GEs were detected in all of the grilled fish samples. The total amount of GEs was higher than 3-MCPDEs. Beef and pork patties with or without sodium chloride (1.5%) were cooked using gaseous fuel. The formation of 3-MCPDEs was significantly increased by the addition of sodium chloride to the meat patties, whereas the concentration of GEs in the cooked meat patties was not changed by the content of sodium chloride. Hexadecane solutions of diacylglycerol or triacylglycerol containing FeCl₃ were heated at 240°C. The formation of 3-MCPDEs was greatly increased by adding FeCl₃ to the solutions of triacylglycerol. The amounts of 3-MCPDEs decreased with the extension of the heating time. From these results, it is suggested that 3-MCPDEs and GEs are formed in saltwater fish and meats by cooking, and that the formation of 3-MCPDEs was affected by chloride in foodstuffs.