Analysis of acrylamide in vegetable chips after derivatization with 2-mercaptobenzoic acid by liquid chromatography–mass spectrometry

Analysis of Maillard reaction precursors and secondary metabolites in Chilean potatoes and neoformed contaminants during frying

Southern Chile native potatoes are an interesting raw material to produce novel snacks like colored potato chips. These novel products should be comprehensively evaluated for the presence of undesirable compounds such as acrylamide, 5-hydroxymethylfurfural and furan, the main neoformed contaminants in starchy rich fried foods. This study evaluated the neoformed contaminant levels and oil content on chips made from eleven Chilean potato accessions and compared them with commercial samples. The neoformed contaminant contents were related to Maillard reaction precursor levels (reducing sugars and asparagine) and secondary metabolites (phenolic compounds and carotenoids). Neoformed contaminants correlated well among them and were weakly correlated with reducing sugars and asparagine. Acrylamide level in native potato chips ranged from 738.2 to 1998.6 μg kg-1 while from 592.6 to 2390.5 μg kg-1 in commercial samples. Thus, there is need to implement neoformed contaminant mitigation strategies at different steps of the production chain of colored potato chips.

Vortex-assisted dispersive low-density liquid-liquid microextraction of xanthydrol derivatized acrylamide in processed chips and water samples for gas chromatographic analysis

Acrylamide, a probable human carcinogen present in heat-processed foods and environmental contaminants, requires sample extraction and preconcentration before chromatographic analysis. The method developed in this study employed derivatization with xanthydrol and dispersive liquid-liquid microextraction utilizing low-density anisole. Durian or potato chips were combined with deionized water, defatted with hexane, and subjected to precipitation of soluble carbohydrates and proteins using clarification reagents. Water samples were filtered through a membrane filter. Acrylamide was derivatized by introducing an acidic methanolic solution of xanthydrol at 50 °C. The derivatized acrylamide was extracted with 70 µL of anisole and vortexed, with the methanol from the xanthydrol solution serving as the disperser solvent. The anisole layer was analyzed using gas chromatography with both flame ionization and mass spectrometric detection. Linear calibration plots exhibited coefficients of determination >0.9997. The precision was measured at <10% RSD, and recoveries ranged from 84% to 107%. The quantitation limit varied from 2 to 10 µg kg-1 for processed chips and from 0.05 to 0.10 µg L-1 for water samples. Acrylamide was detected in all processed chip samples, with some concentrations exceeding the benchmark value of 750 μg kg-1. However, no acrylamide was identified in any of the water samples.

Trends in acrylamide content in selected potato/sweet potato products on the Canadian market

Processed plant-based foods, particularly high carbohydrate-containing foods, are among the greatest contributors to dietary acrylamide, a probable human carcinogen, uptake. Between 2009 and 2020, five surveys were conducted to determine acrylamide in high carbohydrate-containing foods in Canada. These surveys included sampling of potato and sweet potato chips, French fries, and frozen potato/sweet potato products, as a follow-up to our earlier surveys from 2002 - 2008. Samples were analyzed using isotope dilution (13C3-acrylamide) with LC-MS/MS. The highest mean acrylamide levels were found in sweet potato chips. Among potato chips (57 to 4660 ng g-1), one brand consistently showed the highest concentrations with wide variability. Acrylamide concentrations decreased over time in ready-to-eat French fries (from 480 to 358 ng g-1), and one brand showed a clear reduction temporally. Wide variations were observed among brands, among lots/outlets of same brands, and among different food chains. Acrylamide levels in potato chips decreased between 2009 and 2016 (504.3 ng g-1) relative to the period 2002 - 2008 (1096.9 ng g-1). The acrylamide trends observed in the products measured in the latest study indicate that food producers may have adopted mitigation strategies.

Acrylamide in alternative snacks to potato: A review

The snack food market has been changing to keep up with the growing demand for healthier products and, as a result, alternative products to traditional potato chips have been emerging to provide health-related benefits. Extrusion, frying, and baking are the main techniques used worldwide in the processing of snacks and are among the main reasons for the formation of toxic compounds induced by heat, such as acrylamide. This contaminant is formed during thermal processing in foods heated at high temperatures and rich in carbohydrates. Processed potato-based products have been pointed out as the main contributors to acrylamide dietary exposure. Many studies have been conducted on potato chips since the discovery of this contaminant in foods and research on the formation of acrylamide in snacks from other vegetables has begun to be conducted more recently. Thus, this review aims to present a detailed discussion on the occurrence of acrylamide in alternative vegetable snacks that are consumed as being healthier and to address relevant questions about the effectiveness of mitigation strategies that have been developed for these products. Through this research, it was observed that, depending on the vegetable, the levels of this contaminant can be quite variable. Alternative snacks, such as sweet potato, carrot and beetroot may also contain high levels of acrylamide and need to be monitored even more closely than potatoes snacks, as less information is available on these food products. Furthermore, various pretreatments (e.g. bleaching, immersion in solutions containing chemical substances) and processing conditions (heating methods, time, temperature) can reduce the formation of acrylamide (54-99 %) in alternative vegetable snacks.

Results of the BfR MEAL Study: Acrylamide in foods from the German market with highest levels in vegetable crisps

Acrylamide (AA) is formed in foods due to thermal processes. AA was analysed in 230 foods in the first German Total Diet Study and the highest mean levels of AA were found in vegetable crisps (1430 μg/kg), followed by potato pancakes (558) μg/kg) and pan-fried potatoes (450 μg/kg). In various foods, e.g. French fries and sweet potatoes, AA was also tested for different browning degrees and cooking methods. French fries cooked to a browning degree of 3 in all cooking methods exceeded the benchmark level set by the European Union. French fries prepared in the oven and sweet potatoes in the air fryer had the lowest AA levels. In foods from the German market, AA was found also in foods such as popcorn (243 μg/kg), salty sticks (190 μg/kg), and dark chocolate (130 μg/kg). Levels of AA found in our study may support future dietary exposure and food safety assessments.

A ratiometric fluorescent "off-on" sensor for acrylamide detection in toast based on red-emitting copper nanoclusters stabilized by bovine serum albumin

Acrylamide, as a Class 2A carcinogen, poses serious threats to human health. To achieve rapid and accurate determination of acrylamide in food, a ratiometric fluorescent "off-on" sensor was designed by incorporating red-emitting copper nanoclusters and glutathione. Copper nanoclusters with bimodal emission at 395 nm and 650 nm (excited at 310 nm) were synthesized by using bovine serum albumin as the ligand and ascorbic acid as the reductant. With glutathione addition, the fluorescence intensity at 650 nm gradually decreased, while the case at 395 nm slightly increased. The quenched fluorescence at 650 nm was subsequently restored by acrylamide through thiol-ene Michael addition reaction between acrylamide and glutathione. The constructed sensor showed excellent performance towards acrylamide detection in the range of 5-300 μM with a detection limit of 1.48 μM, and was further applied to real-sample detection of acrylamide in toast and exhibited good recoveries (90.29-101.30 %), indicating potential applications of this sensor.

New and Rapid Analytical Method Using HPLC-MS Detection for Acrylamide Determination in Black Ripe Olives

The presence of acrylamide, a known human carcinogen, in various heated foods raises significant concerns among consumers. Therefore, the development of a good analytical method is of paramount interest to the scientific community. Keeping this in view, a rapid, simple, reliable, and low-cost analytical method was developed and validated for acrylamide quantification in black ripe olives. The method consisted of the water extraction of the compounds from crushed olives with the addition of (13C3)acrylamide as an internal standard. The quantification was performed using high-pressure liquid chromatography and mass detection with positive electrospray ionization. The limits of detection and quantification were determined to be 4 and 11 µg/kg, respectively. The developed method exhibited excellent results in terms of accuracy (98.4-104.8%) and intra- and inter-day precision limits, both less than 20%. This new method was carried out by analyzing 15 samples of Spanish commercial black ripe olives, revealing a wide range of values, from 79 to 1068 µg/kg of fruit. The new protocol reduces the analysis time to just one hour per sample versus the minimum 24 h required by gas chromatography and mass detection, meaning that it could be a good option for the routine analysis of acrylamide in black ripe olives, and may be extendable to the analysis of this compound in other foods.

Autofocusing MALDI MS imaging of processed food exemplified by the contaminant acrylamide in German gingerbread

Acrylamide is a toxic reaction product occurring in dry-heated food such as bakery products. To meet the requirements laid down in recent international legal norms calling for reduction strategies in food prone to acrylamide formation, efficient chromatography-based quantification methods are available. However, for an efficient mitigation of acrylamide levels, not only the quantity, but also the contaminant's distributions are of interest especially in inhomogeneous food consisting of multiple ingredients. A promising tool to investigate the spatial distribution of analytes in food matrices is mass spectrometry imaging (MS imaging). In this study, an autofocusing MALDI MS imaging method was developed for German gingerbread as an example for highly processed and instable food with uneven surfaces. Next to endogenous food constituents, the process contaminant acrylamide was identified and visualized keeping a constant laser focus throughout the measurement. Statistical analyses based on relative acrylamide intensities suggest a higher contamination of nut fragments compared to the dough. In a proof-of-concept experiment, a newly developed in-situ chemical derivatization protocol is described using thiosalicylic acid for highly selective detection of acrylamide. This study presents autofocusing MS imaging as a suitable complementary method for the investigation of analytes' distributions in complex and highly processed food.

Acrylamide bioaccessibility in potato and veggie chips. Impact of in vitro colonic fermentation on the non-bioaccessible fraction

Potato-based products contribute largely to the daily intake of acrylamide. In addition to potato crisps, the European Commission has included veggie crisps in the list of foods that should be monitored for their acrylamide content. In the present study, acrylamide content in potato and veggie chips (sweet potato, beetroot and carrot) and their bioaccessibility after in vitro digestion was assessed. The non-bioaccessible fraction was also submitted to in vitro fermentation under colonic conditions. Faecal samples from volunteers of three age groups (children, adolescents and adults) were used to evaluate the microbiota effect on the acrylamide availability. Sweet potato chips exhibited the highest acrylamide content (2342 µg/kg), followed by carrot (1279 µg/kg), beetroot (947 µg/kg) and potato chips (524 µg/kg). After in vitro digestion, acrylamide bioaccessibility was significantly lower in veggie chips (59.7-60.4 %) than in potato chips (71.7 %). Potato and sweet potato chips showed the significantly lowest acrylamide content in the non-bioaccessible fraction (22.8 and 24.1 %, respectively) as compared with beetroot chips (28.4 %). After the fermentation step, acrylamide percentage in the soluble fraction of veggie chips ranged from 43.03 to 71.89 %, the highest values being observed in sweet potato chips fermented with microbiota from children. This fact would involve that the acrylamide was released from the non-bioaccessible fractions by the microbiota. These findings point out that the levels of potentially absorbable acrylamide after the complete gastrointestinal process could be modulated by both the food matrix composition and the microbiota. These factors should be further considered for a more precise risk assessment of dietary acrylamide in humans.

Fluorescent garlic-capped Ag nanoparticles as dual sensors for the detection of acetone and acrylamide

In order to protect human health from the adverse impacts of acrylamide and acetone, simple analytical processes are required to detect low concentrations of acrylamide and acetone. Dual functional garlic-capped silver nanoparticles (G-Ag NPs) have been used as fluorescent sensors for acrylamide and acetone. This technique depends on the quenching of the photoluminescence (PL) intensity of G-Ag NPs with the interaction of either acrylamide or acetone. This fluorescent probe presented high selectivity toward acrylamide with a wide linear response of 0.01-6 mM with a limit of detection (LOD) of 2.9 μM. Moreover, this probe also acted as a selective and sensitive fluorescent sensor for the detection of acetone in the range of 0.1-17 mM with LOD of 55 μM. The applicability of G-Ag NPs as a proposed sensor for acrylamide was evaluated using a potato chips sample with a recovery percentage of 102.4%. Acetone concentration is also quantified in human urine samples and the recoveries ranged from 98.8 to 101.7%. Repeatability and reproducibility studies for acrylamide and acetone offered relative standard deviation (RSD) of 0.9% and 1.5%, and 0.77% and 1.1%, respectively.