Chlorogenic acid increased acrylamide formation through promotion of HMF formation and 3-aminopropionamide deamination

Investigation of Bioactive Complexes of Chitosan and Green Coffee Bean or Artichoke Extracts

The formation of water-insoluble complexes between chitosan (ChS) and caffeoylquinic acid (CQ) derivatives present in artichoke (AE) and green coffee bean (GCBE) extracts was investigated by the equilibrium adsorption method. The UPLC/HPLC analysis revealed that the phenolic compounds accounted for 8.1% and 74.6% of AE and GCBE respectively, and CQ derivatives were the predominant compounds. According to the applied Langmuir adsorption model, anionic compounds present in natural extracts were adsorbed onto the active centers of ChS, i.e., primary amino groups. The driving forces of adsorption were electrostatic interactions between cationic groups of ChS and anionic compounds of natural extracts. Chromatographic analysis revealed that not only CQ derivatives, but also other phenolic compounds of natural extracts were attached to ChS. The release of adsorbed compounds into different media as well as the bioactive properties of complexes were also studied. With the immobilization of bioactives onto ChS, increased and prolonged ABTS^•+ radical scavenging activity and decreased antifungal activity against Fusarium graminearum and Botrytis cinerea were observed compared to those of ChS. The findings of the current study highlight that the adsorption approach could be used to successfully prepare water-insoluble complexes of ChS and components of natural extracts with prolonged antioxidant activity.

Production and Inhibition of Acrylamide during Coffee Processing: A Literature Review

Coffee is the third-largest beverage with wide-scale production. It is consumed by a large number of people worldwide. However, acrylamide (AA) is produced during coffee processing, which seriously affects its quality and safety. Coffee beans are rich in asparagine and carbohydrates, which are precursors of the Maillard reaction and AA. AA produced during coffee processing increases the risk of damage to the nervous system, immune system, and genetic makeup of humans. Here, we briefly introduce the formation and harmful effects of AA during coffee processing, with a focus on the research progress of technologies to control or reduce AA generation at different processing stages. Our study aims to provide different strategies for inhibiting AA formation during coffee processing and investigate related inhibition mechanisms.

Risk/Benefit Evaluation of Chia Seeds as a New Ingredient in Cereal-Based Foods

Chia seed (Salvia hispanica L.) is a food rich in protein, fiber, polyunsaturated fatty acids and antioxidants. Consequently, its incorporation in food formulations may be desirable from a nutritional and healthy point of view. However, there is concern regarding the formation of process contaminants when they are subjected to thermal processing. The objective of this study was to incorporate different amounts of ground chia seeds in a biscuit model to evaluate the effect on the antioxidant capacity and formation of acrylamide and furfurals. Seven standard "Maria-type" biscuit formulations were prepared, replacing wheat flour with different amounts of ground chia seeds (defatted and non-defatted), from 0% (control biscuit) to 15% (respect to total solids in the recipe). Samples were baked at 180 °C for 22 min. Compared with the control biscuit, chia formulations increased the content of nutrients, antioxidant capacity (ABTS) and phenolic compounds (Folin-Ciocalteau method) but also doubled acrylamide levels and even raised more than 10 times furanic compound concentrations. Results indicate that the use of chia seeds as ingredients in new cereal-based formulations would improve the nutritional profile but also increase the occurrence of chemical process contaminants. This paradox should be carefully considered in the context of risk/benefit analysis.

Integrated effect of yeast inoculation and roasting process conditions on the neo formed contaminants and bioactive compounds of Colombian roasted coffee (Coffea arábica)

The rational design of methodologies to control the neoformed compounds occurrence (NFCs), such as acrylamide and hydroxymethylfurfural (HMF) in roasted coffee, must consider the preservation of the bioactive compounds contained in this beverage. The aim of this work was to evaluate the integrated effect of yeast inoculation during the fermentation stage and the modification of roasting parameters on the final concentrations of NFCs and bioactive compounds of roasted coffee. A completely randomized factorial design was used to evaluate the effect of yeast inoculation (with and without inoculation), roasting temperature (150, 180 and 210 °C) and roast degree (medium, dark) on the (i) physicochemical characteristics (volume change, mass loss, water activity, non-enzymatic browning index, antioxidant capacity, total polyphenols, chlorogenic acid and caffeine) as well as HMF and acrylamide levels of roasted coffee. Response variables were analyzed separately by ANOVA and clustering of treatments was explored by PCA. Yeast inoculation did not significantly (p > 0.05) affect volume change, mass loss, antioxidant capacity, total polyphenols content, and caffeine contents. The interaction of evaluated factors significantly decreased (p < 0.05) the acrylamide and HMF contents of roasted coffee (43 % and 56.0 %, respectively). Based on PCA grouping the best treatments were medium roast at 210 °C (inoculated and uninoculated) and at 180 °C (inoculated). Under these conditions it is possible to produce a roasted coffee mitigated in neo formed contaminants that present the physicochemical properties of original product.

UPLC-Q-TOF-MS and NMR identification of structurally different A-type procyanidins from peanut skin and their inhibitory effect on acrylamide

BACKGROUND

Flavan-3-ol polyphenols have been shown to have great advantages in inhibiting acrylamide formation. However, flavan-3-ol polyphenols have structures that vary significantly, and existing research has been focused mainly on the effects of B-type procyanidins and structural units of procyanidins. This study aims to separate structurally different A-type procyanidins from peanut skin and compare their inhibitory effects on acrylamide in an asparagine-glucose simulation system.

RESULTS

Five compounds were separated and identified from peanut skin, including epicatechin-(2β → O → 7, 4β → 8)-ent-epicatechin, epicatechin-(2β → O → 7, 4β → 8)-epicatechin, epicatechin-(2β → O → 7, 4β → 8)-epicatechin-(4β → 6)-catechin, epicatechin-(2β → O → 7, 4β → 8)-epicatechin-(4β → 8)-catechin, and epicatechin-(4β → 6)-epicatechin-(4β → 8, 2β → O → 7)-catechin. All the procyanidins could reduce the acrylamide content within a certain range of concentrations. The highest inhibition rates followed the order of compound 5 (A-type trimer) > compound 1 (A-type dimer) > compound 2 (A-type dimer) > compound 3 (A-type trimer) > compound 4 (A-type trimer). Comparison analysis showed that structurally different A-type procyanidins have various inhibitory effects on acrylamide production, which may be related to their spatial configuration and bond connection mode.

CONCLUSION

Overall, our findings help us to gain a better understanding of the relationship between the structure of procyanidins and their inhibitory effects on acrylamide, particularly the inhibitory effect of A-type. There are potential practical implications if people use A-type procyanidins as acrylamide inhibitors in hot processed foods in the future. © 2022 Society of Chemical Industry.

Machine learning prediction of dual and dose-response effects of flavone carbon and oxygen glycosides on acrylamide formation

Introduction

The extensive occurrence of acrylamide in heat processing foods has continuously raised a potential health risk for the public in the recent 20 years. Machine learning emerging as a robust computational tool has been highlighted for predicting the generation and control of processing contaminants.

Methods

We used the least squares support vector regression (LS-SVR) as a machine learning approach to investigate the effects of flavone carbon and oxygen glycosides on acrylamide formation under a low moisture condition. Acrylamide was prepared through oven heating via a potato-based model with equimolar doses of asparagine and reducing sugars.

Results

Both inhibition and promotion effects were observed when the addition levels of flavonoids ranged 1–10,000 μmol/L. The formation of acrylamide could be effectively mitigated (37.6%–55.7%) when each kind of flavone carbon or oxygen glycoside (100 μmol/L) was added. The correlations between acrylamide content and trolox-equivalent antioxidant capacity (TEAC) within inhibitory range (R2 = 0.85) had an advantage over that within promotion range (R2 = 0.87) through multiple linear regression.

Discussion

Taking ΔTEAC as a variable, a LS-SVR model was optimized as a predictive tool to estimate acrylamide content (R2inhibition = 0.87 and R2promotion = 0.91), which is pertinent for predicting the formation and elimination of acrylamide in the presence of exogenous antioxidants including flavonoids.

Food polyphenols and Maillard reaction: regulation effect and chemical mechanism

Maillard reaction is a non-enzymatic thermal reaction during food processing and storage. It massively contributes to the flavor, color, health benefits and safety of foods and could be briefly segmented into initial, intermediate and final stages with the development of a cascade of chemical reactions. During thermal reaction of food ingredients, sugar, protein and amino acids are usually the main substrates, and polyphenols co-existed in food could also participate in the Maillard reaction as a modulator. Polyphenols including flavan-3-ols, hydroxycinnamic acids, flavonoids, and tannins have shown various effects throughout the process of Maillard reaction, including conjugating amino acids/sugars, trapping α-dicarbonyls, capturing Amadori rearrangement products (ARPs), as well as decreasing acrylamide and 5-hydroxymethylfurfural (5-HMF) levels. These effects significantly influenced the flavor, taste and color of processed foods, and also decreased the hazard products' level. The chemical mechanism of polyphenols-Maillard products involved the scavenging of radicals, as well as nucleophilic addition and substitution reactions. In the present review, we concluded and discussed the interaction of polyphenols and Maillard reaction, and proposed some perspectives for future studies.

Effect of the Integrated Addition of a Red Tara Pods (Caesalpinia spinosa) Extract and NaCl over the Neo-Formed Contaminants Content and Sensory Properties of Crackers

A 2k factorial design with three centrals points was considered to evaluate the effect of adding red Tara pods extract (Caesalpinia spinosa) (440–2560 µg/mL of dough water) and NaCl (0.3–1.7 g/100 g of flour) on the acrylamide (AA) and hydroxymethylfurfural (HMF) content and sensory attributes of crackers. Additionally, the best formulation, defined as that with the lowest AA and HMF content, was compared with a commercial formulation cracker. Red Tara pods extracts were obtained through conventional extraction using pure water (60 °C, 35 min). AA and HMF content were quantified by GC-MS and HPLC-DAD, respectively. The sensory evaluation was carried out using a descriptive analysis on a 10 cm non-structured linear scale. Red Tara pods extract significantly reduced (p < 0.05) the AA and HMF content, while NaCl only influenced the HMF formation. However, the sensory attributes did not significantly change (p > 0.05), excepting the violet-gray color and salty flavor, but at acceptable levels compared with the control sample. The higher the red Tara pods extract concentration (2560 µg/mL of dough water), the lower the neo-formed contaminants (NFCs) content of crackers (AA: 53 µg/kg and HMF: 1236 µg/kg) when salt level was below 3 g/100 g of flour. The action of the proanthocyanidins present in the extracts which trapped the carbonyl groups of sugars probably avoided the formation of both NFCs. Contrarily, NaCl addition (from 0.3 to 1.7 g/100 g of flour) significantly increased (p < 0.05) the HMF formation (from 1236 µg/kg to 4239 µg/kg, respectively), probably through the dehydration of carbohydrates during the Maillard reaction. When explored treatments were compared with a commercial formulated cracker, the highest mitigation effect (reductions of 40% and 32% AA and HMF, respectively) was reached with the addition of 2560 µg/mL of dough water of red Tara pods extract and 0.3 g/100 g of flour of NaCl. The addition of red Tara pods extracts integrated with the control of NaCl levels mitigated the NFCs in crackers, preserving their sensory properties. Future research should be focused on scaling this mitigation technology, considering a better chemical characterization of red Tara pods extracts as well as the validation of its use as functional food ingredient.

Investigation of thermal contaminants in coffee beans induced by roasting: A kinetic modeling approach

The roasting-induced formation of thermal contaminants in coffee beans, including 5-hydroxymethylfurfural (5-HMF), acrylamide (AA), furan (F), 2-methyl furan (2-MF), and 3-methyl furan (3-MF), was investigated using a kinetic modeling approach. Results showed that AA and 5-HMF formation and elimination occur simultaneously in coffee beans during roasting and that the related reactions follow first-order reaction kinetics. The concentrations of F, 2-MF, and 3-MF increased throughout the roasting experiment, and variations in the concentrations of these compounds during roasting could be best described by empirical, logistic model. The increase in weight loss and decrease in moisture content of the beans during roasting also displayed first-order reaction kinetics. High coefficients of determination (R² > 0.981) were observed for all fitted models, and the reaction rate constants of all models followed the Arrhenius law.

Dietary exposure to acrylamide: A critical appraisal on the conversion of disregarded intermediates into acrylamide and possible reactions during digestion

The amount of acrylamide in asparagine rich thermally processed foods has been broadly monitored over the past two decades. Acrylamide exposure can be estimated by using the concentration of acrylamide found in foods and alternatively, biomarkers of exposure are correlated. A better estimation of dietary acrylamide exposure is crucial for a proper food safety assessment, regulations, and public health research. This review addresses the importance of the presence of neglected Maillard reaction intermediates found in foods, that may convert into acrylamide during digestion and the fate of acrylamide in the gastrointestinal tract as a reactive compound. Therefore, it is questioned in this review whether acrylamide concentration in ingested foods is directly correlated with the dietary exposure to acrylamide.

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Neglected Maillard reaction intermediates play role in acrylamide formation in gut.

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Exposure may increase when intermediates are converted into acrylamide in the gut.

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Nucleophiles cause elimination of acrylamide in the intestinal phase.

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The fate of acrylamide during digestion could be important for exposure estimation.

Effect of Hydroxymethylfurfural and Low-Molecular-Weight Chitosan on Formation of Acrylamide and Hydroxymethylfurfural during Maillard Reaction in Glucose and Asparagine Model Systems

The aim of this research was to investigate the effects of the addition of 0.5% hydroxymethylfurfural (HMF) and low molecular chitosan on acrylamide and HMF formation in a food model system, which contains 0.5% glucose, asparagine, and HMF within 30 min of heating at 180 °C. At an interval of 10 min, all solutions were evaluated in the following aspects: reducing sugar, asparagine, acrylamide, HMF content, pH, Maillard reaction products, kinematic viscosity, and color. After heating for 10 min, the kinematic viscosity of solutions containing chitosan reduced significantly. The values of the acrylamide, HMF, and absorbance increased at OD₂₉₄ and OD₄₂₀ (optical density measured at 294 nm and 420 nm) of solutions. Experimental results showed that low-molecular-weight chitosan might be hydrolyzed into much lower molecular weight, followed by the decrease in kinematic viscosity of the solution at pH lower than 6 and the increase in the formation of acrylamide after heating for 30 min.

Effect of formulation and heat treatment on 5-hydroxymethylfurfural formation and quality parameters in dulce de leche

This work assessed the effect of formulation and heat treatment on the formation of HMF, non-enzymatic browning and rheology of dulce de leche (DL). Laboratory scale trials were developed with different DL formulas: whole powdered milk, skimmed milk, and lactose-free skimmed milk, and added sucrose, subjected to different processing temperatures (110°C, 120°C, and 130°C). Additionally, an alternative formulation was designed in which half the sucrose was replaced by 50% tagatose. DL samples were compared with three commercial products in terms of water activity, soluble solids content, pH, colour, apparent viscosity, and HMF concentration. HMF formation in DL was mitigated (35%) in a lactose-free formulation by lowering the process temperature. Moreover, HMF formation was reduced up to 80% replacing sucrose by tagatose without affecting the quality parameters (pH, soluble solids, colour, and apparent viscosity). Decrease in processing temperature and the use of tagatose are viable alternatives for HMF mitigation in DL.

Formation pathways and precursors of furfural during Zhenjiang aromatic vinegar production

As a flavor and quality parameter, furfural has potential undesirable effects. This study aimed to elucidate furfural formation, including generation, pathways, and possible precursors during the production of Zhenjiang aromatic vinegar. A cereal vinegar model, rich in saccharides, amino acids, and organic acids, was used to explore the potential precursors. Furfural and 5-hydroxymethylfurfural (HMF) mainly generated during the decoction process, but the HMF also increased during the aging process. Three pathways were found to coexist for the formation of furfural: (i) the Maillard reaction induced by saccharides and nitrogenous compounds, (ii) the direct cleavage of pentose, and (iii) indirect conversion from pentosan, which only made a minor contribution. Furfural was not formed from HMF or l-ascorbic acid in vinegar. Instead, ribose, xylose, arabinose, galacturonic acid, glucuronic acid, and pentosan were the main precursors. These insights may be useful for the risk/benefit balance and improve the flavor quality and safety.

Organic Selenium as Antioxidant Additive in Mitigating Acrylamide in Coffee Beans Roasted via Conventional and Superheated Steam

Selenium is an essential micronutrient with significant antioxidant activity promising in mitigating the formation of acrylamide during high-temperature roasting. In this study, green coffee beans pretreated with selenium (Se-coffee) were investigated on their selenium uptake, selenium retention in green and roasted beans, antioxidant activities, and formation of acrylamide during conventional and superheated steam roasting. Comparisons were made with positive (pretreated without selenium) and negative (untreated) controls. The acrylamide formation was significantly inhibited in Se-coffee (108.9-165.3 μg/kg) compared to the positive and negative controls by 73.9% and 52.8%, respectively. The reduction of acrylamide by superheated steam roasting only observed in the untreated coffee beans (negative control) by 32.4% parallel to the increase in its antioxidant activity. Selenium pretreatment significantly increased antioxidant activity of the roasted Se-coffee beans after roasting although soaking pretreatment significantly reduced antioxidant activity in the green beans. Acrylamide reduction in the roasted coffee beans strongly correlated with the change in antioxidant capacities after roasting (∆FRAP, 0.858; ∆DPPH, 0.836). The results indicate that the antioxidant properties of the organic selenium suppressed acrylamide formation during coffee roasting.

Exploring the relationship between potato components and Maillard reaction derivative harmful products using multivariate statistical analysis

The correlation between potato components and Maillard reaction derivative harmful products (MRDHPs) formation during heat-processing was assessed in nine commercial potato varieties in China. Principal component analysis (PCA) combined with canonical correlation analysis (CCA) approach was performed to explore their relationships. The variables contributing most to the PCA results were extracted for CCA, and the results indicated that several amino acids, including lysine, tryptophan, alanine, phenylalanine, aspartate, and glutamate, have significant impacts on acrylamide and β-carboline heterocyclic amine formation. Moreover, 5-O-caffeoylquinic acid, 3-O-caffeoylquinic acid, α-solanine, and α-chaconine were also important factors associated with acrylamide and β-carboline heterocyclic amine formation. Optimally using raw potato varieties based on the impacts of these factors can help control MRDHP formation during thermal processing. For the first time, such approach was applied, which may be a useful tool for discovering the correlation of food components and MRDHPs.

Interaction of Acrylamide, Acrolein, and 5-Hydroxymethylfurfural with Amino Acids and DNA

Acrylamide, acrolein, and 5-hydroxymethylfurfural (HMF) are food-borne toxicants produced during the thermal processing of food. The α,β-unsaturated carbonyl group or aldehyde group in their structure can react easily with the amino, imino, and thiol groups in amino acids, proteins, and DNA via Michael addition and nucleophilic reactions in food and in vivo. This work reviews the interaction pathways of three toxins with amino acids and the cytotoxicity and changes after the digestion and absorption of the resulting adducts. Their interaction with DNA is also discussed. Amino acids ubiquitously exist in foods and are added as nutrients or used to control these food-borne toxicants. Hence, the interaction widely occurring in foods would greatly increase the internal exposure of these toxins and their derived compounds after food intake. This review aims to encourage further investigation on toxin-derived compounds, including their types, exposure levels, toxicities, and pharmacokinetics.

Formation and Identification of Two Hydroxmethylfurfural-Glycine Adducts and Their Cytotoxicity and Absorption in Caco-2 Cells

Our previous research showed that thioacetal and Schiff base formed between 5-hydroxymethylfurfural (HMF) and cysteine or lysine considerably decreased the cytotoxicity of HMF. In this study, two adol condensation adducts, named 2β-amino-3α-hydroxy-3-(5-(hydroxymethyl)furan-2-yl)propanoic acid (HGA) and 2α-amino-3β-hydroxy-3-(5-(hydroxymethyl)furan-2-yl)propanoic acid (HGB), were prepared from the reaction products of glycine and HMF, and their cytotoxicities were investigated in Caco-2 cells. Compared with HMF, HGA and HGB displayed lower cytotoxicities against Caco-2 cells with IC₅₀ values of 36.50 and 43.47 mM, respectively, versus 16.11 mM (HMF). In contrast to our findings in thioacetal and Schiff base products, HGA and HGB underwent a very high metabolism rate (99%) in Caco-2 cells. HGA and HGB may degrade to other products instead of HMF since no extracellular or intracellular HMF was detected.

Acrylamide in coffee: formation and possible mitigation strategies - a review

It is widely known that acrylamide, present in some different heat-treated foods, is an important toxic compound to humans. Coffee beverage is one of the most important sources of acrylamide, because the raw bean contains the reaction substrates and it is processed at very high temperature during roasting. Due to its high consumption all over the world, it is necessary to find applicable solutions to decrease the concentration of this undesired Maillard reaction product.The present review summarizes the advance made in understanding the acrylamide formation and describes the potential acrylamide reduction strategies along all coffee production steps, from raw material to coffee brew preparation with a dominant focus on roasting stage.Currently, it is quite established that the selection of the highest quality Arabica green coffee variety, high roasting thermal input and shortest brewing techniques lead to low final acrylamide levels. There are also few innovative interventions proposed for acrylamide control in coffee such as enzymatic treatments of raw material, vacuum or steam roasting, roasted beans supercritical fluid extraction, final beverage treatments like yeast fermentation and amino acids/additive additions. However, for these strategies the impact on the desired sensorial and nutritional coffee brew properties must be evaluated and some proposed procedures are still difficult to be applied at real industrial scale. Furthermore, in-depth studies are needed in order to find appropriate and practical solutions for acrylamide mitigation in coffee with a holistic risk/benefit approach.

Identification of a 5-Hydroxymethylfurfural-Lysine Schiff Base and Its Cytotoxicity in Three Cell Lines

5-Hydroxymethylfurfural (HMF) can undergo the Maillard reaction with amino acids. However, the safety of the products remains unknown. In this study, a HMF-lysine Schiff base named (E)-N⁶-((5'-(hydroxymethyl)furan-2'-yl)methylene)lysine (HML) was identified and detected for the first time in baked foods. HML formation significantly decreased the cytotoxicity (IC₅₀) of HMF against GES-1 cells (81.81 versus 5.02 mM and 73.76 versus 2.94 mM for HML versus HMF at 24 and 48 h, respectively), EA.hy926 cells (86.05 versus 4.85 mM and 77.22 versus 0.71 mM, respectively), and Caco-2 cells (155.77 versus 36.84 mM and 112.70 versus 18.51 mM, respectively). Exposure of Caco-2 cells to HMF at 10.0 mM triggered cell apoptosis of 14.02% (versus 8.54% in the control), whereas exposure to HML at 10-15 mM hardly increased cell apoptosis. Moreover, the absorption capacities of HMF and HML by Caco-2 cells were equivalent (p > 0.05) at 7.23-12.57% after incubation at 2 mM for 30-150 min.

Water-in-oil-in-water double emulsions loaded with chlorogenic acid: release mechanisms and oxidative stability

Chlorogenic acid (CA) is a natural compound used as an antioxidant in the preparation of food, drugs, and cosmetics. Due to their low stability and bioavailability, many researchers have studied the encapsulation of CA in various delivery colloidal systems. The aim of this study was to evaluate the stability of water-in-oil-in-water (W/O/W) double emulsions loaded with CA and its antioxidant capacity. For this purpose, CA-W/O/W double emulsions were prepared using Span 80 and lecithin as lipophilic emulsifiers, and Tween 20 as a hydrophilic emulsifier. The influence of nature of lipophilic emulsifiers, the presence of chitosan (CH) in the internal and external aqueous phases, pH, temperature and the storage time of W/O/W double emulsions were also investigated. Depending on the preparation conditions, the W/O/W double emulsions showed the droplet size in the range 9.13 ± 0.55 μm-38.21 ± 1.87 μm, the creaming index 34%-78% and the efficiency encapsulation 79.45 ± 1.5%-88.13 ± 1.9%. Zeta potential values were negative for the W/O/W double emulsion without CH (-36.8 ± 2.02mV; -27.3 ± 1.75mV) and positive for the W/O/W double emulsions with CH in the external aqueous phase (+6.5 ± 0.42mV; 28.6 ± 0.92mV). The study of the release of CA from W/O/W double emulsions has highlighted two mechanisms: one based on the coalescence between the water inner droplets or between the oil globules as well as a diffusion releasing mechanism. The oxidative stability parameters of the W/O/W double emulsions, such as the peroxide value (POV) and the conjugated diene content (CD) were measured.

Epicatechin Adducting with 5-Hydroxymethylfurfural as an Inhibitory Mechanism against Acrylamide Formation in Maillard Reactions

This study aimed to investigate the inhibitory mechanism of epicatechin (EC) on the formation of acrylamide in Maillard reactions. The glucose + asparagine model is a typical chemical system used to investigate acrylamide formation. 5-Hydroxymethylfurfural (HMF) is an important carbonyl intermediate in Maillard reactions and can also react with asparagine to form acrylamide. Time courses showed that EC inhibited more HMF than acrylamide in the glucose + asparagine model heated at 180 °C. The reduction of EC on acrylamide formation in the HMF + asparagine model was about 70%, while that in the glucose + asparagine model was about 50%. Moreover, HMF decreased significantly faster when it was heated in the presence of EC. Liquid chromatography-mass spectrometry analysis revealed the formation of adducts between EC and HMF, and the dimeric adducts were verified in fried potato chips. These results suggested that the condensation of EC and HMF was one of the key steps leading to the inhibition of acrylamide. UV-visible spectra analysis showed that some polymerization products had absorption in the visible region and contributed to the development of browning, which was underestimated in the past.

The Formation of Acrylamide from and Its Reduction by 3-Aminopropanamide Occur Simultaneously During Thermal Treatment

3-Aminopropanamide (3-APA) is the direct precursor of acrylamide produced in the Maillard reaction between asparagine and reducing sugars. In this research, we found that 3-APA could reduce acrylamide by the formation of adducts between acrylamide and 3-APA via Michael addition. The effects of temperature, heating duration and 3-APA/acrylamide ratio on the reduction of acrylamide were investigated. Addition of 3-APA to acrylamide at a molar ratio of 5:3 at 160 °C for 20 min reduced acrylamide by up to 47.29%. The major adduct was identified as 3,3',3'-nitrilotris, and its cytotoxicity on Caco-2 cells was evaluated to be much lower than acrylamide. The viability of Caco-2 cells retained at 88.31% and 86.43% after incubation with 16 mM 3,3',3'-nitrilotris for 24 and 48 hr, respectively, while those incubated with the same concentration of acrylamide were 23.33% and 19.12%, respectively.

PRACTICAL APPLICATION

The current study reported 3-APA could reduce acrylamide through the Micheal addition reaction between 3-APA and acrylamide. The adduct showed significantly reduced cytotoxicity compared to acrylamide. The research is critical in evaluation and control of food contaminants. The results brought new insights in the area of food safety, especially in the mechanism researches on formation and mitigation of endogenous contaminants in thermal-processed foods.

Formation of a Hydroxymethylfurfural-Cysteine Adduct and Its Absorption and Cytotoxicity in Caco-2 Cells

Adducts of 5-hydroxymethylfurfural (HMF)-amino acids are formed during food processing and digestion; the elimination capacity of in vitro intestinal digests of biscuits, instant noodles, and potato crisps for HMF is 652, 727, and 540 μg/g, respectively. However, the safety of these adducts is unknown. In this study, an HMF-cysteine adduct named 1-dicysteinethioacetal-5-hydroxymehtylfurfural (DCH), which was found to be produced in the gastrointestinal tract after HMF intake, was prepared to test its effect toward Caco-2 cells. Compared with HMF, the adduct displayed lower cytotoxicity against Caco-2 cells with an IC₅₀ value of 31.26 mM versus 14.95 mM (HMF). The DCH did not induce cell apoptosis, whereas HMF significantly increased the apoptosis rate after incubation at concentrations of 16, 32, and 48 mM for 72 h. DCH showed an absorption rate considerably lower than that of HMF by Caco-2 cells. Lower absorption of DCH may result in lower toxicity compared with HMF against Caco-2 cells. Intracellular transformation of DCH has been observed.

Formation and elimination reactions of 5-hydroxymethylfurfural during in vitro digestion of biscuits

This study investigated the possible formation and elimination reactions of 5-hydroxymethylfurfural (HMF) with amino and sulfhydryl groups in commercial biscuits during simulated in vitro gastrointestinal digestion. At the end of gastric phase, significant increase was observed in HMF contents of biscuits (p<0.05). By high-resolution mass spectrometry (HRMS) analysis, it was confirmed that sugar dehydration products such as 3-deoxyglucosone and 3,4-dideoxyglucosone accumulated in biscuits during baking were converted to HMF under gastric conditions. However, reactions of HMF with amino acids proceeded with the progress of digestion. HRMS analysis in both HMF-amino acid model systems and in biscuits confirmed that formed HMF reacted with amino and sulfhydryl groups through Michael type addition. In addition, formation of Schiff base during intestinal phases led to a significant decrease in the concentrations of HMF (p<0.05).

Effect of Selected Mercapto Flavor Compounds on Acrylamide Elimination in a Model System

The effect of four mercapto flavor compounds (1,2-ethanedithiol, 1-butanethiol, 2-methyl-3-furanthiol, and 2-furanmethanethiol) on acrylamide elimination were investigated in model systems. The obtained results showed that mercaptans assayed were effective in elimination arylamide in a model system. Their reactivities for decreasing acrylamide content depended on mercaptan's molecular structure and acrylamide disappearance decreased in the following order: 1,2-ethanedithiol > 2-methyl-3-furanthiol > 1-butanethiol > 2-furanmethanethiol. Mercaptans were added to acrylamide to produce the corresponding 3-(alkylthio) propionamides. This reaction was irreversible and only trace amounts of acrylamide were formed by thermal heating of 3-(alkylthio) propanamide. Although a large amount disappeared, only part of the acrylamide conversed into 3-(alkylthio) propionamides. All of these results constitute a fundamental proof of the complexity of the reactions involved in the removal of free acrylamide in foods. This implies mercapto flavor/aroma may directly or indirectly reduce the level of acrylamide in food processing. This study could be regarded as a pioneer contribution on acrylamide elimination in a model system by the addition of mercapto flavor compounds.

Support vector regression-guided unravelling: antioxidant capacity and quantitative structure-activity relationship predict reduction and promotion effects of flavonoids on acrylamide formation

We used the support vector regression (SVR) approach to predict and unravel reduction/promotion effect of characteristic flavonoids on the acrylamide formation under a low-moisture Maillard reaction system. Results demonstrated the reduction/promotion effects by flavonoids at addition levels of 1–10000 μmol/L. The maximal inhibition rates (51.7%, 68.8% and 26.1%) and promote rates (57.7%, 178.8% and 27.5%) caused by flavones, flavonols and isoflavones were observed at addition levels of 100 μmol/L and 10000 μmol/L, respectively. The reduction/promotion effects were closely related to the change of trolox equivalent antioxidant capacity (ΔTEAC) and well predicted by triple ΔTEAC measurements via SVR models (R: 0.633–0.900). Flavonols exhibit stronger effects on the acrylamide formation than flavones and isoflavones as well as their O-glycosides derivatives, which may be attributed to the number and position of phenolic and 3-enolic hydroxyls. The reduction/promotion effects were well predicted by using optimized quantitative structure-activity relationship (QSAR) descriptors and SVR models (R: 0.926–0.994). Compared to artificial neural network and multi-linear regression models, SVR models exhibited better fitting performance for both TEAC-dependent and QSAR descriptor-dependent predicting work. These observations demonstrated that the SVR models are competent for predicting our understanding on the future use of natural antioxidants for decreasing the acrylamide formation.

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

A review of the interactions between acrylamide, microorganisms and food components

Acrylamide (AA) and its metabolites have been recognized as potential carcinogens, but also they can cause other negative symptoms in human or animal organisms and therefore this class of chemical compounds has attracted a lot of attention.

Investigations on the effect of antioxidant type and concentration and model system matrix on acrylamide formation in model Maillard reaction systems

The formation of acrylamide in model Maillard reaction systems containing phenolic compounds was examined, with regards to phenolic type, concentration, and model system matrix. In dry glyoxal/asparagine waxy maize starch (WMS) systems, 9 out of 10 examined phenolics demonstrated an inhibiting effect, with the most significant reductions (55-60%) observed for caffeoylquinic acids. In WMS glucose/asparagine systems, examination of three different concentrations (0.1, 0.5 and 1 μmol/g WMS) suggested a 'minimum effective concentration' for epicatechin and caffeic acid, whilst addition of caffeoylquinic acids resulted in dose-dependent acrylamide reduction (25-75%). The discordant results of further studies utilising different matrices (dry and wet-to-dry) indicated that, apart from the nature and chemical reactivity, the matrix and the physical state of the reactants might be important for acrylamide formation.

Role of antioxidants and phytochemicals on acrylamide mitigation from food and reducing its toxicity

Nowadays, the presence of acrylamide in lots of fried and baked foods raises concerns due to its potential to cause toxicity and cancer in animals and human. Consequently, a number of papers have focused on evaluation of various chemicals in reduction of acrylamide in various food sources, as well as decreasing its related toxicities. In addition, plants are important sources of diverse metabolites demonstrating either possible effectiveness in acrylamide toxicity or reduction of acrylamide content in food sources. In this paper, we have criticized all relevant studies in terms of acrylamide mitigation from food by phytochemicals and antioxidants, and the influence of herbal medicines and phyto-pharmaceuticals on reduction of acrylamide toxicity in both animals and human.

Role of plant polyphenols in acrylamide formation and elimination

Acrylamide found in thermal-treated foods has led to an intensive and persistent research effort, since it is a neurotoxic, genotoxic and probable carcinogenic compound to humans. Plant polyphenols are the most abundant antioxidants in human diet. Several researches indicated that the polyphenols affected the acrylamide formation during heating. However, the controversial effects of the polyphenols on acrylamide formation were related to their structure, concentrations, and antioxidant capacity, as well as reaction condition. Polyphenols can inhibit acrylamide formation through trapping of carbonyl compounds and preventing against lipid oxidation, while some special polyphenols can enhance the acrylamide content by providing carbonyl groups, accelerating the conversion from 3-aminopropionamide (3-APA) to acrylamide and inhibiting acrylamide elimination. This review concludes the effects of polyphenols in the Maillard reaction and food systems conducted so far, aimed to give an overview on the role of plant polyphenols in acrylamide formation and elimination.