Formation of furan in baby food products: Identification and technical challenges

Furan is generally produced during thermal processing of various foods including baked, fried, and roasted food items such as cereal products, coffee, canned, and jarred prepared foods as well as in baby foods. Furan is a toxic and carcinogenic compound to humans and may be a vital hazard to infants and babies. Furan could be formed in foods through thermal degradation of carbohydrates, dissociation of amino acids, and oxidation of polyunsaturated fatty acids. The detection of furan in food products is difficult due to its high volatility and low molecular weight. Headspace solid-phase microextraction coupled with gas chromatography/mass spectrometer (GC/MS) is generally used for analysis of furan in food samples. The risk assessment of furan can be characterized using margin of exposure approach (MOE). Conventional strategies including cooking in open vessels, reheating of commercially processed foods with stirring, and physical removal using vacuum treatment have remained unsuccessful for the removal of furan due to the complex production mechanisms and possible precursors of furan. The innovative food-processing technologies such as high-pressure processing (HPP), high-pressure thermal sterilization (HPTS), and Ohmic heating have been adapted for the reduction of furan levels in baby foods. But in recent years, only HPP has gained interest due to successful reduction of furan because of its nonthermal mechanism. HPP-treated baby food products are commercially available from different food companies. This review summarizes the mechanism involved in the formation of furan in foods, its toxicity, and identification in infant foods and presents a solution for limiting its formation, occurrence, and retention using novel strategies.     

Furan in heat‐treated foods: Formation,exposure, toxicity,and aspects of risk assessment

Furan is formed in a variety of heat‐treated foods through thermal degradation of natural food constituents. Relatively high levels of furan contamination are found in ground roasted coffee, instant coffee, and processed baby foods. European exposure estimates suggest that mean dietary exposure to furan may be as high as 1.23 and 1.01 μg/kg bw/day for adults and 3‐ to 12‐month‐old infants, respectively. Furan is a potent hepatotoxin and hepatocarcinogen in rodents, causing hepatocellular adenomas and carcinomas in rats and mice, and high incidences of cholangiocarcinomas in rats at doses ≥2 mg/kg bw. There is therefore a relatively low margin of exposure between estimated human exposure and doses that cause a high tumor incidence in rodents. Since a genotoxic mode of action cannot be excluded for furan‐induced tumor formation, the present exposures may indicate a risk to human health and need for mitigation. This review summarizes the current knowledge on mechanisms of furan formation in food, human dietary exposure to furan, and furan toxicity, and highlights the need to establish the risk resulting from the genotoxic and carcinogenic properties of furan at doses lower than 2 mg/kg bw.     

Analysis of furan in heat-processed foods consumed in Korea using solid phase microextraction–gas chromatography/mass spectrometry (SPME–GC/MS)

Furan (C₄H₄O) is a volatile compound formed during the Maillard reaction and was recently classified as a possible human carcinogen (group 2B) by the International Agency for Research on Cancer. It has been reported to occur in various canned and jarred foods that undergo heat treatment. The aim of the present study was to optimise the sample preparation for furan analysis using solid phase microextraction–gas chromatography/mass spectrometry (SPME–GC/MS), according to the food matrix. We also performed the monitoring and risk assessment of furan in various food products. The optimised fibre exposure temperatures, time and amount of sample of liquid, semi solid and paste state foods were 5 g (ml), 50 °C, and 20 min, respectively. The level of furan in canned meat (32.16 ng/g) was the highest among the samples studied. The furan levels in canned fish, canned vegetable, nutritional/diet drinks, canned soups and jarred sauces were 29.40, 22.86, 7.28, 18.54 and 21.52 ng/g, respectively. Furan concentrations in baby food products were between 3.43 and 97.21 ng/g. Exposure estimates (14.59 ng/kg bw/day) of baby foods was the highest among all the tested food samples. However, the exposure estimate of baby foods was lower than that prescribed by the US FDA.     

Furan in commercial baby foods from the Spanish market: estimation of daily intake and risk assessment

ABSTRACT

The occurrence of furan in commercial baby food samples from the Spanish market was evaluated using an automated headspace solid-phase microextraction method coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS). A total of 76 baby food samples including infant formula, baby cereals, fruit in cans and/or jars, vegetables, meat, and fish, were surveyed for furan content. The lowest concentration of this compound was found in infant formula (<0.02–0.33 ng ml^?1), and cereal-based food (0.15–2.1 ng g^?1) while baby food containing fish showed the highest concentrations (19–84 ng g^?1). Following recommendation of the European Food Safety Authority (EFSA), the effect on furan content was evaluated of consumer home preparation of foods, heating and handling. Furan concentrations were reduced by up to 35% when samples were heated in a dish using microwave oven and by up to 53% when a hot water bath was used. Finally, we estimated the furan intake from baby food consumption (0.002–1.18 µg kg^?1 body weight day^?1) and we calculated the margin of exposure (MOE) from samples as purchased and also after home preparation of the food. For infant formula and cereal baby foods, the MOEs (26,278–412,776) indicated no infant health concern or priority, while for meat and fish-based baby foods the values pointed to a potential public health risk, even considering the furan losses during preparation at home.     

Furan and Methylfurans in Foods: An Update on Occurrence,Mitigation, and Risk Assessment

The acceptance of many foods is related to traditional cooking practices, which create taste and texture and are important to digestibility, preservation, and the reduction of foodborne illnesses. A wide range of compounds are formed during the cooking of foods, a number of these have been shown to lead to adverse effects in classical toxicological models and are known as food processing contaminants (FPC). It is essential that the presence and effects of such compounds alone and in combination within the diet are understood such that proportionate risk management measures can be developed, while taking a holistic view across the whole value chain. Furan and alkylfurans (principally 2‐ and 3‐methylfuran) are highly volatile FPC, which are formed in a wide range of foods at low amounts. The focus of research to‐date has been on those foods, which have been identified to be most consequential in terms of being sources of exposure, namely jarred and canned foods for infants and young children (meals and drinks) and coffee (roast and ground, soluble). This report presents (i) new industry data on the occurrence of furan and methylfurans in selected food categories following previous coffee studies, (ii) the most salient parameters that impact furan formation, and (iii) aspects of importance for the risk assessment.     

Advances in Mycotoxin Research: Public Health Perspectives

Aflatoxins, ochratoxins, fumonisins, deoxynivalenol, and zearalenone are of significant public health concern as they can cause serious adverse effects in different organs including the liver, kidney, and immune system in humans. These toxic secondary metabolites are produced by filamentous fungi mainly in the genus Aspergillus, Penicillium, and Fusarium. It is challenging to control the formation of mycotoxins due to the worldwide occurrence of these fungi in food and the environment. In addition to raw agricultural commodities, mycotoxins tend to remain in finished food products as they may not be destroyed by conventional processing techniques. Hence, much of our concern is directed to chronic health effects through long‐term exposure to one or multiple mycotoxins from contaminated foods. Ideally risk assessment requires a comprehensive data, including toxicological and epidemiological studies as well as surveillance and exposure assessment. Setting of regulatory limits for mycotoxins is considered necessary to protect human health from mycotoxin exposure. Although advances in analytical techniques provide basic yet critical tool in regulation as well as all aspects of scientific research, it has been acknowledged that different forms of mycotoxins such as analogs and conjugated mycotoxins may constitute a significant source of dietary exposure. Further studies should be warranted to correlate mycotoxin exposure and human health possibly via identification and validation of suitable biomarkers.     

Are Chileans exposed to dietary furan?

Chilean consumer preferences include foods that may contain considerable amounts of furan, a potential human carcinogen. However, there is no information regarding dietary exposure to furan in Chile. Thus, the objective of this work was to determine the Chilean exposure to dietary furan. To accomplish this objective, the furan concentration of 14 types of commercial foods processed at high temperature were analysed based on a modified headspace-GC/MS (HS-GC/MS) method in which the limits of detection for different food matrices ranged from 0.01 to 0.6 ng g^?1. In addition, a risk assessment was made with exposure estimates based on dietary data from national studies on different age groups (9-month-old babies, school children, adults and elderly people). Of the food items surveyed “American”-type coffee (espresso coffee plus hot water) obtained from automatic coffee machine (936 ng g^?1) and low moisture starchy products like crisps and “soda”-type crackers showed the highest furan concentrations (259 and 91 ng g^?1, respectively). Furthermore, furan was also found in samples of breakfast cereals (approximately 20 ng g^?1), jarred fruit baby foods (8.5 ng g^?1) and orange juice (7.0 ng g^?1). School children (aged 9–13 years) represented the highest intake of furan (about 500 ng kg^?1_bw day^?1), with margins of exposure of 2479 and 2411, respectively, which points to a possible public health risk.     

Some factors affecting the formation of furan in heated foods

Levels of furan in various foods were measured before and after heating under heating and laboratory conditions. The effect of contact with can coatings, sealing gaskets and the epoxidized oils used in gasket manufacture on furan formation was studied. The objective was to identify factors affecting furan formation. Furan present in heat-processed food samples persisted during cooking. Furan was shown to form in foods on heating, although it did not accumulate to a significant degree on heating in an open vessel. There were no interactions between foods and cans, can coatings or gaskets that had a significant influence on furan formation. Furan accumulated particularly in heat-processed canned and jarred foods because they are sealed containers that receive a considerable thermal load. Heating epoxidized oils used in sealing gaskets formed furan. At the levels used in gaskets, however, epoxidized oils should not affect the formation of furan in foods.     

Effect of consumer cooking on furan in convenience foods

The effect of domestic preparation regimes on the level of the heat-formed toxicant furan was studied to provide useful information for exposure assessment and advice for manufacturers and consumers. Foods were cooked in a saucepan on a gas hob or microwaved and furan was determined by headspace sampling with gas chromatography-mass spectrometry. In general, furan levels did not decrease as much when foods were cooked in a microwave oven when compared with the same foods cooked in a saucepan. Furan levels decreased in most canned and jarred foods after heating in a saucepan. Low levels of furan in soups in cartons were not changed by any procedure. Furan decreased slightly in foods on standing before consumption, but did so more rapidly on stirring. The levels also decreased slightly when foods were left to stand on plates; this observation is attributed to the volatility of furan.     

Effect of consumer cooking on furan in convenience foods

The effect of domestic preparation regimes on the level of the heat-formed toxicant furan was studied to provide useful information for exposure assessment and advice for manufacturers and consumers. Foods were cooked in a saucepan on a gas hob or microwaved and furan was determined by headspace sampling with gas chromatography-mass spectrometry. In general, furan levels did not decrease as much when foods were cooked in a microwave oven when compared with the same foods cooked in a saucepan. Furan levels decreased in most canned and jarred foods after heating in a saucepan. Low levels of furan in soups in cartons were not changed by any procedure. Furan decreased slightly in foods on standing before consumption, but did so more rapidly on stirring. The levels also decreased slightly when foods were left to stand on plates; this observation is attributed to the volatility of furan.     

Survey of furan in heat processed foods by headspace gas chromatography/mass spectrometry and estimated adult exposure

Furan is a suspected human carcinogen that is formed in some processed foods at low ng per g levels. Recent improvements in analytical methodology and scientific instrumentation have made it possible to accurately measure the amount of furan in a wide variety of foods. Results from analysis of more than 300 processed foods are presented. Furan was found at levels ranging from non-detectable (LOD, 0.2-0.9 ng g^-1) to over 100 ng g^-1. Exposure estimates for several adult food types were calculated, with brewed coffee being the major source of furan in the adult diet (0.15 µg kg^-1 body weight day^-1). Estimates of mean exposure to furan for different subpopulations were calculated. For consumers 2 years and older, the intake is estimated to be about 0.2 µg kg^-1 body weight day^-1.     

辽宁地区部分食品中二氧化硫的膳食暴露风险评估

目的 评估辽宁地区部分食品中二氧化硫残留暴露对我省居民健康的潜在风险。方法 随机从辽宁省大型商场和小型农贸市场采集样品共330份, 采用蒸馏法进行二氧化硫残留量检测。基于点评估和概率评估两种评估方式, 对食物中二氧化硫残留的膳食暴露进行风险评估。结果 经检测的不同食品中二氧化硫的膳食摄入风险值均远小于100%。运用风险评估软件@risk7.6进行概率评估, 在50%、75%、90%、99%暴露量位点下, 不同食物二氧化硫的风险商(hazard quotient, HQ)值均远小于1。结论 辽宁地区食物中二氧化硫残留量在人体可接受范围内, 无明显膳食风险。     

Rapid and improved determination of furan in baby foods and infant formulas by headspace GC/MS

Furan is a 5-membered ring compound with high volatility. The U.S. Food and Drug Administration (FDA) has recently published a report on the occurrence of furan in a large number of thermally processed foods. However, the FDA's analytical method, using standard curve addition, is not suitable for high-throughput routine laboratory operations. We developed a rapid and improved method for determination of furan in foods by headspace GC/MS. Quantification was achieved by using an internal standard of d4-furan and an external calibration curve of furan normalized against the internal standard. The incubation temperature for equilibration was set at 60 degrees C to avoid the formation of furan during analysis. The levels of furan in baby foods and infant formulas were determined with this method. Validation data showed good precision and accuracy. The LOD and LOQ were 0.2-0.5 ng/g and 0.5-2 ng/g for various food matrixes, respectively. The level of furan detected was in the range of 1.4 to 90 ng/g in baby foods and in the range of non-detectable to 36 ng/g in infant formulas.     

N ϵ-(carboxymethyl)lysine: A Review on Analytical Methods,Formation, and Occurrence in Processed Food,and Health Impact

Foods are often heat processed and may contain advanced glycation end products (AGE). One of the most widely studied AGE is N ^?-(carboxymethyl)lysine (CML); nevertheless, knowledge on dietary CML is fragmentary. This study aimed to review current scientific knowledge on analytical methods to determine CML contents in food, chemical pathways of CML formation in food, occurrence of CML in food, and health implications of dietary exposure to CML. Chemical analyses of CML in food products are carried out by immunochemical assays and instrumental methods, but the former method may interfere with the food matrix. CML is formed in food through various chemical pathways, depending on food ingredients and processing conditions. The compound is present in many cooked foods, with relatively high concentrations in carbohydrate-rich foods and dairy products. Dietary CML is very likely to impair human health, but full cause-effect evidence is not available yet. More studies on metabolic effects and impact of food-derived CML on human health should be performed. Food production should be optimized to minimize CML concentrations, while maintaining acceptable microbiological safety and organoleptic properties of the final food product. To this end, more insights into effects of food composition and processing conditions on CML formation are necessary.     

Survey of furan in heat processed foods by headspace gas chromatography/mass spectrometry and estimated adult exposure

Furan is a suspected human carcinogen that is formed in some processed foods at low ng per g levels. Recent improvements in analytical methodology and scientific instrumentation have made it possible to accurately measure the amount of furan in a wide variety of foods. Results from analysis of more than 300 processed foods are presented. Furan was found at levels ranging from non-detectable (LOD, 0.2–0.9 ng g^?1) to over 100 ng g^?1. Exposure estimates for several adult food types were calculated, with brewed coffee being the major source of furan in the adult diet (0.15 µg kg^?1 body weight day^?1). Estimates of mean exposure to furan for different subpopulations were calculated. For consumers 2 years and older, the intake is estimated to be about 0.2 µg kg^?1 body weight day^?1.     

Effect of oxygen availability and pH on the furan concentration formed during thermal preservation of plant-based foods

Thermally treated fruit- and vegetable-based foods are important contributors to the furan exposure of children and adults. Furan reduction by adding or removing precursors from the product has proven to be challenging because of major food constituents and interactions involved in the reaction pathways leading to furan formation. Instead of intervening at the precursor level, it might be more feasible to influence these formation pathways by adjusting the matrix properties of the product. As opposed to many previous literature sources, the present study investigated the effects of oxygen availability (normal versus reduced) and pH (acid versus low acid) on the furan formation in a real food system. Different combinations of both matrix properties were prepared in a reconstituted potato purée and subjected to a thermal treatment with a pasteurisation or sterilisation intensity. Irrespective of the addition of the furan precursors ascorbic acid, fructose and fatty acids, a considerable furan reduction was observed for the sterilised purées (F₁₂₁¹⁰ = 15 min) with either a reduced oxygen availability (0.1–1.8 mg l^–1) or at pH 3. The effects of both matrix properties were less pronounced in the pasteurised purées (P₉₀¹⁰ = 10 min), because of the lower furan concentrations. Even though the mechanisms of furan reduction for both types of matrix properties could not be fully elucidated, the results showed that lowering the oxygen concentration or pH prior to thermal processing offers a powerful, additional strategy for furan mitigation in thermally treated plant-based foods.     

Occurrence and risk assessment of mycotoxins,acrylamide, and furan in Latvian beer

This work reports data on the occurrence of nine mycotoxins and two food processing contaminants – acrylamide and furan – in a total of 100 beers produced in Latvia. Mycotoxins were detected by high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry, acrylamide by HPLC coupled with quadrupole-Orbitrap mass spectrometry, and furan by headspace gas chromatography-mass spectrometry. The most frequently occurring mycotoxins were HT-2 and deoxynivalenol (DON), which were detected in 52% and 51% of the analysed samples. The highest content was observed for DON, reaching the maximum of 248 µg kg^?1. Furan was ubiquitous, and 74% of the samples contained acrylamide. In terms of the estimated exposure, the biggest potential risk was identified for HT-2 representing more than 11% of tolerable weekly intake. The margin of exposure approach indicated the exposure to furan through beer as significant, this parameter being close to the critical limit.     

Risk assessment of aflatoxins in food in Africa

Aflatoxins are secondary metabolites of the fungi Aspergillus flavus and A. parasiticus, occur widely on many staple foods and cause a broad range of detrimental health effects in animals and humans. As a consequence, maximum tolerated levels (MTLs) have been legislated in many countries. However, in developing countries where food safety compliance can be low and significant levels of the food supply are locally consumed by the producers or purchased at local markets, more comprehensive strategies are required. In this regard, risk analysis with its components of risk assessment, risk management and risk communication, is an important tool in dealing with food safety issues. Risk assessment for aflatoxin B₁ in Africa has been performed using the carcinogenic potency, established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and applying it to typical food products and consumption across the continent, to illustrate the significant health implications caused by the intake of high levels of contaminated foods. Highlighted in this assessment is the fact that even low levels of contamination, which might of themselves fall within legislated limits, can have serious health implications due to high levels of consumption, i.e. meeting a MTL does not of itself guarantee food safety. Recent developments have highlighted the growth retardation and immune suppression caused by aflatoxin exposure in human populations in west Africa. Using the limited data available on both these health effects, a first step has been taken to incorporate them into a risk assessment paradigm quantifying the risk of immunosuppression, malnutrition and stunting in children exposed to aflatoxins and highlighting again how excessive consumption of foods meeting MTLs can carry significant health risks.     

Effect of cooking or handling conditions on the furan levels of processed foods

The aim of this study was to investigate the possible effects of cooking or handling conditions on the concentration of furan in processed foods. The analytical method used to analyse furan levels in foods was optimized based on solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). In baby soups, the concentration of furan decreased by up to 22% after opening a lid for 10 min. In the baby food in retort packaging, the level of furan was reduced by 15–33% after heating the foods at 50°C without a lid. Furan in rice seasonings was evaporated completely after heating the foods at 60°C. Regarding powered milk, the levels of furan were too low to be compared under various conditions. The levels of furan decreased to 58% in beverage products for babies, after storing them at 4°C for 1 day without a lid. The levels of furan in canned foods such as cereal and vegetable were reduced by zero to 52% when they were stored without stirring in a refrigerator at 4°C for 1 day. When we boiled canned fish, the furan present was almost completely evaporated. It is recommended that canned meats be heated up to 50–70°C for the reduction (26–46%) of furan levels. The levels of furan in instant and brewed coffee samples were significantly reduced after storing for 11 to 20 min at room temperature without a lid (p < 0.05).