Formation of 2-amino-α-carbolines in pan-fried poultry and 32P-postlabelling analysis of DNA adducts

 Amino-α-carbolines are food-derived genotoxic heterocyclic aromatic amines (HAAs) that have been shown to be carcinogenic in rodents, to induce preneoplastic foci in rat liver and to be active in a number of genotoxicity tests, inducing gene mutations, DNA strand breaks and cell transformation. 2-Amino-α-carboline (AαC) has been estimated to account for about 20% of the carcinogenic HAAs that are ingested with the diet. Using the tandem cartridge solid-phase extraction procedure we were able to show that in pan-fried poultry the proportion of AαC and its 3-methyl derivative (MeAαC) account for 15% of the HAA fraction. Covalent DNA adducts are considered to be the primary lesions in chemical carcinogenesis. Both AαC and MeAαC have been shown to induce covalent DNA adducts in vitro and in vivo. Formation of DNA adducts was investigated by ³²P-postlabelling analysis in vitro in primary rat hepatocytes treated with 10–500 μM AαC or MeAαC. While for MeAαC-derived adducts the highest response was obtained with the nuclease P1 enhancement procedure, AαC adducts were most efficiently detected upon ³²P-postlabelling preceded by a cartridge enrichment step. Adduct levels detected were dose dependent but decreased for the higher doses due to cytotoxic effects. We have characterised the major DNA adducts of AαC and MeAαC as deoxyguanosine derivatives with the amino-α-carboline bound via the 2-amino group to the C8 position of guanine. Received: 23 April 1998     

Enhancement of colon and stomach carcinogenesis in 1,2-dimethylhydrazine-treated rats fed a diet high in heterocyclic amines

 Epidemiological studies have linked the consumption of red meat and the consumption of highly browned meats containing high levels of heterocyclic aromatic amines (HCAs) to increased risk of colorectal cancer or polyps. We have examined the effects of long-term feeding of beef-containing diets with low and high levels of HCAs (in the context of a low- or high-beef tallow diet) on a standard 1,2-dimethylhydrazine (DMH)-induced colon tumorigenesis protocol. Feeding of a beef diet high in HCAs resulted in more DMH-induced colon adenocarcinomas, but only in the context of a low fat diet. The high HCA diets increased stomach tumors in all DMH-treated rats. An apparent interaction of high HCA levels with a high fat level reduced the colon tumor incidence and tumor numbers in those rats on diets containing both these factors. These results support the epidemiological data linking well-cooked meat to increased risk for colon and stomach cancer, but the role of the dietary fat level remains puzzling. Additionally, we examined the DNA of liver, colon, and stomach from control rats (not treated with DMH) fed a high level of HCAs for 27 weeks. The genomic DNA was analyzed for the presence of 2-amino-1-methyl-6-phenylimidazo[4,5-f]pyridine (PhIP) adducts by ³²P-postlabeling analysis and was also used in PCR to amplify the rat p53 and Apc genes, followed by direct dye-terminator DNA sequencing. Results showed that no PhIP adducts were present in any tissue. In addition, there were no signature p53 or Apc gene mutations seen in the colon or stomach DNA. These results indicate that the high level of HCAs present in a diet of well-cooked meat does not cause (1) persistent PhIP adducts similar to those produced by feeding pure PhIP at high doses or (2) p53 and Apc gene mutations in nontumor tissue. Received: 23 April 1998     

Assessment of the dietary habits and polycyclic aromatic hydrocarbon exposure in primary school children

Thirty Italian children, 7–9 year aged, living in Naples were investigated on their dietary habits and on polycyclic aromatic hydrocarbon (PAH) exposure by a food diary-questionnaire and one week duplicate diet sample analyses. Daily total food consumption mean value was 632 ± 215 g day^?1, median value 613 g day^?1. The daily energy intake and the diet composition meanly agreed with the official guidelines for the Italian children. Sixteen PAHs were simultaneously detected and, according to the European Food Safety Authority (EFSA) approach, benzo[a]pyrene; benzo[a]pyrene + chrysene (PAH2); PAH2 + benz[a]anthracene + benzo[b]fluoranthene (PAH4); PAH4 + benzo[k]fluoranthene + benzo[ghi]perylene + dibenz[a, h]anthracene + indeno[1,2,3-cd]pyrene (PAH8) were considered in evaluating the children's dietary exposure to PAHs. The benzo[a]pyrene (BaP) median concentrations in foods varied from 0.06 to 0.33 µg kg^?1. Only three samples of cooked foods (one fish and two meat samples) exceeded legal limits fixed by the European Union for BaP. Daily median intakes of benzo[a]pyrene, PAH2, PAH4, and PAH8 were 153; 318; 990; 1776 ng day^?1; their median exposure values were 5; 10; 28; 54 ng kg^?1 bw day^?1. The Margins of Exposure (MOEs) in median consumers agreed with the EFSA safety values except for PAH8.     

Dietary exposure and risk assessment of European Union priority (EU 15+1) polycyclic aromatic hydrocarbons from milks and milk powders in China

Dairy products, characterized by rich nutrition and unique flavor, occupy an increasing share of the human diet with the development of higher living standards. However, trace hazardous contaminants in dairy products, such as polycyclic aromatic hydrocarbons (PAH), are arousing public concern. In this study, we investigated 82 milks and milk powders from Shanghai markets for the occurrence of 20 PAH, including 16 European Union priority (EU 15+1) PAH and 4 derivatives. Furthermore, we carried out a risk assessment of dietary exposure of PAHs from dairy products based on detection results and data on body weight and dietary intake obtained from questionnaires. Two assessment methods were used in this study: the incremental lifetime cancer risk (ILCR) and margin of exposure (MOE) methods. The ILCR of all age groups was 10^?6 to 10^?4, indicating a potential but acceptable carcinogenic risk. The MOE of the 4 groups (divided by age and sex) was >10⁴, indicating no significant carcinogenic risk of PAH exposure from dairy products. In both methods, children had the highest risk because of their greater consumption of dairy products, followed by seniors, young adults, and middle-aged adults. Results of this study provide reference data on the exposure level and health risk of PAHs from dairy product intake.     

Assessment of the estrogenicity of the diet of a healthy female Spanish population based on its isoflavone content

Phytoestrogens are natural components of plants consumed by humans. The hormonal activity of these substances has long been known. Various in vitro tests have demonstrated the agonistic or antagonistic estrogenic activity of some phytoestrogens. The objective of this study was to estimate the supply of isoflavones in the diet of a healthy adult female population and to assess its estrogenic effect. The diet was assessed by questionnaire and the estrogenicity of the estimated isoflavone content was tested by E-screen, finding a mean total estrogenic capacity of 0.129 × 10^?10 eq.E₂ (12.9 pmol day^–1), corresponding to a daily isoflavone intake of 265.8 μg day^–1. This study offers a preliminary insight into the phytoestrogen content of the diet of a healthy active population of Spanish women. The effects of this additional hormonal burden are highly controversial, and this approach to estimating dietary phytoestrogen intake of specific populations may help to elucidate its implications for human health.     

The contribution of fruits and vegetables to dietary intake of polyphenols and antioxidant capacity in a Mexican rural diet: Importance of fruit and vegetable variety

There is mounting evidence of the health-protective role of the consumption of fruits and vegetables, which are the major contributors to dietary polyphenol intake. Lack of knowledge about the consumption of phytochemicals in the Mexican diet makes it difficult to evaluate their health significance. The aim of this study was therefore to estimate the contribution of fruit and vegetable consumption to dietary polyphenol intake and dietary antioxidant capacity in a rural population in Mexico. Despite a low intake of fruits and vegetables (< 400 g/day) in the Mexican rural diet, the mean daily intake of dietary polyphenols (> 800 mg/day) and dietary antioxidant capacity (1000-2000 ??mol trolox equivalents/day) from fruits and vegetables was similar to those determined in the Spanish Mediterranean diet. Local fruits and vegetables consumed in the Mexican rural diet are rich in polyphenols with antioxidant properties and are important source of bioactive compounds and dietary fibers. Fruit and vegetable intake needs to be promoted and lifestyle and environmental factors enhanced to improve the health status of obese Mexican rural populations.     

Dietary intake of dioxins in Japan in 2016 with time trends since 1998

Total diet samples collected from seven regions throughout Japan in 2016 were analysed for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls (DL-PCBs), known collectively as dioxins. This led to estimates of the latest dietary intake of these contaminants for the general Japanese population (≥1 year old). The average daily intake of dioxins for a person weighing 50 kg, calculated at non-detected congener concentrations assumed to be equal to zero, was estimated to be 0.54 pg TEQ (toxic equivalents) kg^?1 body weight (bw) day^?1. This value is well below the tolerable daily intake of 4 pg TEQ kg^?1 bw day^?1 for dioxins in Japan. The average intake was highest from fish and shellfish, followed by meat and eggs. The TEQ contribution of the fish and shellfish group to the total dietary TEQs was significant (89%). The DL-PCBs accounted for about 67% of the dioxin intake. The latest dioxin intake level was compared with previous estimates from total diet study results obtained annually since 1998 to determine the time trends in the dietary intake of dioxins in Japan. Overall, the average dioxin intake appeared to be decreasing gradually during the period of study. The previous average intakes of dioxins ranged from 0.58 to 1.9 pg TEQ kg^?1 bw day^?1. The latest average intake was the lowest since 1998 and was about one-third of the average intake in 1998. This decreasing trend in the dietary intake of dioxins was mainly influenced by the decreased dioxin intakes from two food groups, fish and shellfish, and meat and eggs.     

DNA烷基化损伤研究进展

DNA的烷基化损伤可导致复制过程中的错配,被认为是引起基因突变及相关疾病的原因。烷基化DNA加合物是重要的DNA烷基化损伤产物。本文介绍了DNA烷基化损伤的修复机制,以及产物。综述了烷化类损伤试剂,及其作用于细胞产生烷基化加合物的机理。讨论了烷化类DNA加合物与吸烟之间的关系。综述了烷化类DNA加合物的检测方法,展望了烷基化DNA加合物的研究方向及作为烷基化损伤标志物的研究前景。      

Dietary exposure to acrylamide from potato crisps to the Spanish population

Potato crisps are one of the food commodities that contribute most to overall dietary human exposure of acrylamide. This investigation has estimated the dietary exposure to acrylamide form potato crisps in the Spanish population. Sampling of potato crisps (n = 36) from 16 different producers were carried out in March 2008. An average level of 740 µg kg^?1 (ranging from 81 to 2622 µg kg^?1; minimum to maximum) and a median of 592 µg kg^?1 were obtained. Acrylamide levels in marketed potato crisps have been significantly reduced (nearly to 50%) compared with a previous sampling performed 4 years earlier. The observed signal value (90th percentile) was 1377 µg kg^?1 with 86% of the samples with acrylamide levels lower than 1000 µg kg^?1. Dietary exposure to acrylamide from potato crisp consumption in the total Spanish population was estimated to be 0.042 µg kg^?1 body weight day^?1 by using a deterministic approach based on the National consumption database. In a second study, dietary exposure (based on a 3-day food record) was determined to be 0.053 µg kg^?1 body weight day^?1 for the adult population (17–60 years) and 0.142 µg kg^?1 body weight day^?1 for children (7–12 years). The contribution of potato crisps to the estimated dietary acrylamide exposure of the Spanish population is moderate as compared with other European Member States.     

Effects of enzymes in diets with varying energy levels on growth and egg production performance of Japanese quail

The present study was conducted to evaluate the effect of feed‐grade enzyme supplementation in diets with varying levels of energy on the performance of growing and laying Japanese quails. Day‐old Japanese quails, 504 in number, were subjected to six dietary treatments with six replicates at each treatment. Each replicate had 14 chicks. The dietary treatments consisted of three energy levels ie 12.15 MJ (2900 kcal), 11.30 MJ (2700 kcal) and 10.48 MJ (2500 kcal) ME kg^?1 diet and two enzyme levels (0 and 0.5 g kg^?1 diet). A metabolism trial was conducted at the fourth week of age. At the end of week 5, 10 quails (five of each sex) per treatment were sacrificed for carcass characteristics and 20 female quails from each of the six dietary groups were housed in individual laying cages and fed respective layer diet to study the laying performance and egg quality up to 20 weeks of age. Body weight gains of quails fed 12.15 MJ or 11.30 MJ ME kg^?1 diets were significantly higher (p < 0.01) than those fed diets with 10.46 MJ ME kg^?1 diet. Feed intake was significantly lower (p < 0.01) in birds that received diet with 12.15 MJ ME kg^?1 than in birds that diets containing either 11.30 or 10.46 MJ ME kg^?1 diet. Feed conversion ratio (p < 0.01) was best at 12.15, followed by 11.30 and 10.46 MJ ME kg^?1 diet. Enzyme supplementation did not improve the growth performance, feed intake or feed conversion efficiency of quails. Enzyme addition also did not influence nitrogen retention or energy or dry matter metabolizability. The carcass characteristics did not differ because of energy or enzyme supplementation. Feed intake increased significantly (p < 0.01) as the dietary energy level decreased. The egg production and quality characteristics remained almost similar in all the dietary treatments. It was concluded that the optimum dietary energy level for quail was 12.15 MJ (2900 kcal) ME kg^?1 during the growing phase and 11.30 MJ (2700 kcal) ME kg^?1 during the laying phase. Addition of feed enzymes to conventional diets containing varying levels of maize, soyabean meal, fish meal and deoiled rice bran was not beneficial to improve growth, carcass traits, egg production performance or nutrient utilization. Copyright © 2004 Society of Chemical Industry     

Concentrations and health hazards of polycyclic aromatic hydrocarbons in selected commercial brands of milk

The concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) were determined in twenty popular commercial brands of milk in the Nigerian market after saponification with ethanolic KOH and cyclohexane extraction and clean up using a gas chromatography with flame ionization detection. The concentrations of the Σ16 PAHs in these brands of milk ranged from 15.6 to 1,711.8 μg kg^?1. The dominant PAH compounds in these brands of milk were 3-and-4-rings PAHs. The dietary intake of BaP, PAH2, PAH4 and PAH8 were 0–53.9 and 0–369.6 ng kg^?1 bw day^?1 respectively. Using these indicators for occurrence and effects (BaP, PAH2, PAH4 and PAH8) PAHs in food, the margin of exposure were <10,000 in 15–30 % of the brands.     

Enhancing the selenium content of bovine milk through alteration of the form and concentration of selenium in the diet of the dairy cow

Since estimated dietary selenium intake in the UK has declined steadily from around 60 µg day^?1 in 1975 to 34 µg day^?1 in 1997, there is a need to increase selenium intake from staple foods such as milk and milk products. An experiment was therefore done to investigate the relationship between dietary source and concentration of selenium and the selenium content of bovine milk. In a 3 × 3 factorial design, 90 mid‐lactation Holstein dairy cows were supplemented over 8 weeks with either sodium selenite (S), a chelated selenium product (Selenium Metasolate?) (C) or a selenium yeast (Sel‐Plex?) (Y) at three different dietary inclusion levels of 0.38 (L), 0.76 (M) and 1.14 (H) mg kg^?1 dry matter (DM). Significant increases in milk selenium concentration were observed for all three sources with increasing inclusion level in the diet, but Y gave a much greater response (up to +65 µg l^?1) than the other two sources of selenium (S and C up to +4 and +6 µg l^?1 respectively). The Y source also resulted in a substantially higher apparent efficiency of transfer of selenium from diet to milk than S or C. Feeding Y at the lowest dietary concentration, and thus within the maximum level permitted under EU regulations, resulted in milk with a selenium concentration of 28 µg l^?1. If the selenium concentration of milk in the UK was increased to this value, it would, at current consumption rates, provide an extra 8.7 µg selenium day^?1, or 11 and 14% of daily recommended national intake for men and women respectively. Copyright © 2004 Society of Chemical Industry     

Monitoring of polycyclic aromatic hydrocarbons (PAH) in food supplements containing botanicals and other ingredients on the Dutch market

Food supplements can contain polycyclic aromatic hydrocarbons (PAH). The European Food Safety Authority (EFSA) has defined 16 priority PAH that are both genotoxic and carcinogenic and identified eight priority PAH (PAH8) or four of these (PAH4) as good indicators of the toxicity and occurrence of PAH in food. The current study aimed to determine benzo[a]pyrene and other EFSA priority PAH in different categories of food supplements containing botanicals and other ingredients. From 2003 to 2008, benzo[a]pyrene exceeded the limit of quantification (LOQ) in 553 (44%) of 1258 supplements with a lower-bound mean of 3.37?µg?kg^?1. In 2008 and 2009, benzo[a]pyrene and 12 other EFSA priority PAH were determined in 333 food supplements. Benzo[a]pyrene exceeded the LOQ in 210 (63%) food supplements with a lower-bound mean of 5.26?µg?kg^?1. Lower-bound mean levels for PAH4 and PAH8(-indeno[1,2,3-cd]pyrene) were 33.5 and 40.5?µg?kg^?1, respectively. Supplements containing resveratrol, Ginkgo biloba, St. John's wort and propolis showed relatively high PAH4 levels in 2008 and 2009. Before 2008, supplements with these ingredients and also dong quai, green tea or valerian contained relatively high benzo[a]pyrene levels. On average, PAH4 intake resulting from food supplement use will be at the lower end of the range of contributions of main food groups to PAH4 exposure, although individual food supplements can contribute significantly to PAH4 exposure. Regular control of EFSA indicator PAH levels in food supplements may prove a way forward to reduce further the intake of PAH from food.     

Annual variation of dietary deoxynivalenol exposure during years of different Fusarium prevalence: a pilot biomonitoring study

Dietary exposure to deoxynivalenol (DON) has been reported previously in the UK, but levels were low and most individuals are well protected by the maximum permitted levels in food set by the European Commission. However, no information is available on annual fluctuation in dietary DON exposure. We hypothesised that dietary DON exposure may vary when individuals consume cereals derived from harvests with low (2011) and high (2012) Fusarium prevalence. In this pilot study, spot urine samples were collected in years 1 and 2 from 15 volunteers following their habitual diet. Urinary DON was analysed by LC-MS/MS to estimate 24-h DON excretion and daily dietary DON intake. DON was detectable in all urine samples with an average excretion of 10.08 ± 9.13 µg/24-h urine in year 1 which significantly (p = 0.005) increased to 24.84 ± 13.83 µg/24-h urine in year 2. This resulted from an estimated dietary intake of 195.94 ± 166.44 ng DON kg^–1 BW in year 1 and 518.64 ± 292.49 ng DON kg^–1 BW in year 2. Based on these estimates, the tolerable daily intake for DON was exceeded in 13% of occasions in year 2 and none in year 1. This pilot study is based on estimates of DON intake derived from urinary DON excretion. Results suggest that DON exposure varies annually and that current maximum levels might not sufficiently protect consumers during years of high Fusarium prevalence.     

Ochratoxin A: An overview on toxicity and carcinogenicity in animals and humans

Ochratoxin A (OTA) is a ubiquitous mycotoxin produced by fungi of improperly stored food products. OTA is nephrotoxic and is suspected of being the main etiological agent responsible for human Balkan endemic nephropathy (BEN) and associated urinary tract tumours. Striking similarities between OTA-induced porcine nephropathy in pigs and BEN in humans are observed. International Agency for Research on Cancer (IARC) has classified OTA as a possible human carcinogen (group 2B). Currently, the mode of carcinogenic action by OTA is unknown. OTA is genotoxic following oxidative metabolism. This activity is thought to play a central role in OTA-mediated carcinogenesis and may be divided into direct (covalent DNA adduction) and indirect (oxidative DNA damage) mechanisms of action. Evidence for a direct mode of genotoxicity has been derived from the sensitive 32P-postlabelling assay. OTA facilitates guanine-specific DNA adducts in vitro and in rat and pig kidney orally dosed, one adduct comigrates with a synthetic carbon (C)-bonded C8-dG OTA adduct standard. In this paper, our current understanding of OTA toxicity and carcinogenicity are reviewed. The available evidence suggests that OTA is a genotoxic carcinogen by induction of oxidative DNA lesions coupled with direct DNA adducts via quinone formation. This mechanism of action should be used to establish acceptable intake levels of OTA from human food sources.     

Estimate of dietary exposure to sulphites in child and adult populations in the Basque Country

Sulphites are widely used as a preservative and antioxidant additive in food. The aim of this study was to assess dietary sulphite intake in adults aged 35–65 years and in children aged 4–18 years living in the Basque Country, northern Spain. We determined sulphite concentrations in 909 samples covering 16 food types. The maximum permitted levels were exceeded in 17% of samples. Making recommended assumptions for non-quantifiable results, estimates of mean lower and upper bounds were calculated for sulphite concentrations in each food type. These sulphite data were combined with consumption data derived from 8417 adults from the European Prospective Investigation in Cancer and Nutrition cohort in Gipuzkoa, recruited in 1992–1995 using a diet history method, and 1055 children from the Basque Country Nutrition Children Survey, conducted in 2004–2005 using two 24-h recall questionnaires to assess diet. The results were compared with the acceptable daily intake (ADI) proposed by the Joint Expert Committee on Food Additives (JECFA). The mean dietary exposure to sulphites was 0.08 mg kg^?1 bw day^?1, only 11% of the ADI in the overall group of children (4–18 years old), but the acceptable intake was exceeded by 4% of 4–6 year olds. For the adults (35–65 years old), the mean dietary exposure was 0.31 mg kg^?1 bw day^?1, 45% of the ADI, but the acceptable intake was exceeded in 14.6% of cases. The major contributing foods were minced meat and other meat products for children and wine for adults.     

Effects of dietary supplementation of cysteamine on growth performance,carcass quality,serum hormones and gastric ulcer in finishing pigs

A study was conducted to determine the effects of graded levels of dietary inclusion of a cysteamine (Cs) preparation on growth performance, carcass quality, plasma hormone levels, gastric pH and occurrence of gastric ulcer in finishing pigs. A total of 384 Landrace × Large White finishing pigs, (192 gilts and 192 barrows) with an average initial body weight of 66.05 ± 0.623 kg (mean ± SEM) were randomly divided into 24 floor pens, with eight gilts and eight barrows in each pen (9.2 m²) as one experimental unit. The 24 pens of pigs were randomly allocated to one of three diets: (1) a maize/soybean meal basal diet; (2) the basal diet plus 30 mg Cs kg^?1 diet; and (3) the basal diet plus 50 mg Cs kg^?1 diet. Dietary supplementation of Cs had quadratic effects (P < 0.01) on final body weight and average daily gain, with optimal responses occurring at 30 mg kg^?1. Dietary supplementation of Cs quadratically improved (P < 0.01) average daily feed intake and feed/gain ratio, with optimal responses occurring at 30 mg kg^?1. Dietary supplementation of Cs had a quadratic effect (P < 0.01) on muscle RNA/DNA ratio. Furthermore, dietary supplementation of Cs reduced (P < 0.05) back‐fat thickness. Dietary supplementation of Cs had quadratic effects (P < 0.05) on plasma glucagon and T₃ hormone levels, with optimal responses occurring at 30 mg kg^?1, but had no effect (P > 0.05) on plasma growth hormone, insulin and T₄ levels. There were no apparent pathological changes seen in the stomach mucosa of pigs fed at 30 mg Cs kg^?1 compared with the control diet. It is concluded that a low dose of dietary inclusion of Cs at 30 mg kg^?1 can improve growth performance and carcass quality without adverse effects on the stomach in finishing pigs. Copyright © 2005 Society of Chemical Industry     

Dietary intake assessment of caramel colours and their processing by-products 4-methylimidazole and 2-acetyl-4-tetrahydroxy-butylimidazole for the Chinese population

ABSTRACT

The aim of the study was to assess the dietary intake of caramel colours and their by-products 4-methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) for the Chinese population. Based on the typical and maximum reported use levels of caramel colours in 15 food categories, the dietary intakes of combined and single-class caramel colours of Classes I, III and IV were estimated with the food consumption data from the China National Nutrient and Health Survey. Using the mean values of 4-MEI and THI contents in Class III and Class IV Caramel colour samples, the exposures to 4-MEI and THI from dietary caramel colours were derived. The results showed that the combined and individual average dietary caramel colour intakes for the Chinese population of different age groups were estimated to be 232–60.3 mg kg^?1 bw day^?1 for combined caramels, 5.9–29.2 mg kg^?1 bw day^?1 for Class I, 7.7–29.6 mg kg^?1 bw day^?1 for Class III, 21.2–54.3 mg kg^?1 bw day^?1 for Class IV, which were far below the group acceptable daily intake (ADI) and respective ADIs. The combined intake of 4-MEI from Class III and IV caramel colours was estimated to be 3.8–5.2 μg kg^?1 bw day^?1 on average, and 12.9–27.1 μg kg^?1 bw day^?1 at 95th-97.5th percentile for the general population. The anticipated exposure to THI from Class III caramel colours was estimated to be 0.1–0.3 μg kg^?1 bw day^?1 on average and 0.5–1.7 μg kg^?1 bw day^?1 at 95th–97.5th percentile for the general population. The dietary caramel colours intakes and the exposures to 4-MEI and THI from dietary caramel colour for the Chinese population were considered to be of low health concern based on the present toxicological data. Soy sauce, vinegar and compound seasonings were found to be the main contributors to the dietary intake of caramel colours.     

Maillard reaction products profile and intake from Spanish typical dishes

The Mediterranean diet is proposed as one of the healthiest dietary models, but its contribution to Maillard reaction products (MRP) intake is unknown. Several Spanish dishes typical of the Mediterranean diet (paella, Spanish omelette, salmorejo or churros) were selected to evaluate MR extension and the presence of MRP. CIELab colour, browning at different wavelengths, furosine, hydroxymethylfurfural, furfural and acrylamide were determined, and content/serving was calculated. Development of MR was affected by ingredients: when protein levels were high and carbohydrates low, early MRP were formed, regardless of the culinary process. There was found a correlation between acrylamide and hydroxymethylfurfural. The possible underestimation of deterministic calculations of acrylamide dietary exposure is discussed. This study presents a first approximation to enable the MRP intake from the Mediterranean diet to be calculated, taking into account the moisture content and the serving size of dishes.     

Bacterial folate biosynthesis and colorectal cancer risk: more than just a gut feeling

Abstract

Folate is a B-vitamin with an important role in health and disease. The optimal folate status with regard to human health remains controversial. A low intake of natural folate as well as excessive intake of synthetic folic acid, were previously linked to an increased risk of colorectal cancer or with aberrant molecular pathways related to carcinogenesis in some studies. Importantly, most studies conducted so far, solely focused on dietary intake or circulating levels of folate in relation to cancer risk. Notably, diet or dietary supplements are not the only sources of folate. Several bacteria in the gastrointestinal tract can synthesize B-vitamins, including folate, in quantities that resemble dietary intake. The impact of bacterial folate biosynthesis concerning human health and disease remains unexplored. This review highlights current insights into folate biosynthesis by intestinal bacteria and its implications for processes relevant to cancer development, such as epigenetic DNA modifications and DNA synthesis. Moreover, we will reflect on the emerging question whether food-grade or intestinal bacteria can be considered a potential target to ensure sufficient levels of folate in the gastrointestinal tract and, hence the relevance of bacterial folate biosynthesis for disease prevention or treatment.