Effects of starch damage and yeast fermentation on acrylamide formation in bread

Miniaturized matrix solid-phase dispersion assisted by deep eutectic solvent for acrylamide determination in bread samples

Acrylamide determination is important to state its quantity in baked food preventing any potential carcinogenic effects. Matrix solid-phase dispersion (MSPD) extraction is an extraction procedure based on a homogenization phase between a solid sample and a solid dispersing material to break sample increasing analyte extraction yield, often used for acrylamide determination. The addition of a green deep eutectic solvent (DES) during the MSPD homogenization phase improves the analyte extraction, giving the possibility to reduce the amount of organic solvent used. In this work, a miniaturized MSPD extraction assisted by a DES was developed to determine acrylamide in bread, using high-performance liquid chromatography coupled with mass spectrometry detection. The optimized procedure provides 1:1 (w/w) matrix-to-dispersing material ratio, 2 mL of methanol as extraction solvent, and 50 μL of choline chloride-glycerol DES added during the homogenization phase. Method validation ensured good results with minimum recoveries of 90%, high precision with a maximum intra-day error of 4%, and inter-day error of 6%. Limit of detection and limit of quantification resulted to be 16 μg/kg and 35 μg/kg, respectively. This miniaturized extraction procedure represents a good alternative to those reported in the literature, guaranteeing great performance and respecting green chemistry principles.

Prediction acrylamide contents in fried dough twist based on the application of artificial neural network

Acrylamide forms through the reaction between reducing sugars and asparagine in the thermal processing of food. Detection measures like LC-MS, HPLC are time-consuming and costly, which inspired us to use back propagation-artificial neural networks (BP-ANN) based on a genetic algorithm to establish an acrylamide prediction model in fried dough twist. The effects of frying time and temperature on acrylamide contents, as well as the color difference and acid value at different time and temperature were determined. Acrylamide content was found significantly correlated with temperature (P < 0.01) and was correlated with acid value and color difference (P < 0.05). Thus, temperature, acid value, and the color difference were set as input layers, and acrylamide content was set as an output layer to establish a BP-ANN network prediction model. The weight and threshold values in the BP-ANN network prediction model were optimized with a multi-population genetic algorithm and the test data were set to obtain an optimized BP neural network predicting model. The results showed that the Levenberg-Marquardt back-propagation training algorithm of the BP-ANN model with 5 hidden layer neurons and 0.005 learning rate was the best predictive performance, which the correlation coefficients (R) of test and validation were 0.9640 and 0.8999, suggesting a good fitting and strong approximation ability. The BP-ANN model is expected to accurately predict the content of acrylamide in fried dough twist.

The Properties of Damaged Starch Granules: The Relationship Between Granule Structure and Water-Starch Polymer Interactions

The morphology of wheat starch granules with different damaged starch (DS) content was analyzed using a particle size analyzer and scanning electron microscopy (SEM); the granular structure was studied using FT-IR spectroscopy and X-ray diffraction (XRD); and the granule-water interaction was evaluated by thermogravimetric analysis (TGA) and dynamic vapor sorption (DVS). The increase in the level of DS shifted the population of B-type granules towards larger particle diameters and shifted the population of A-type granules towards smaller particle diameters. The appearance of the surface of the starch-damaged granules was rough and flaky (SEM images). Crystallinity reductions were related to higher mechanical damage levels of the granular structure (FT-IR and XRD). Higher DS increased the liquid-water absorption capacity of the granules. Higher DS was associated with increments in less-bound water proportions and reductions in more strongly bound water proportions and related to reductions in the evaporation temperature of these water populations (TGA analyses). Concerning DVS data, the results suggested that the driving force for water-monolayer attachment to the starch granules decreased as DS increased. Therefore, it was suggested that the changes in granule structure led to a weaker water-starch polymer chain interactions due to the increase in DS. The results contribute to a better understanding of the influence of mechanical damage on the starch granular structure, which could be related to the rheological and thermal behavior of starch-based systems with different DS.

Molecular changes and interactions of wheat flour biopolymers during bread-making: Implications to upcycle bread waste into bioplastics

This study aims to understand the molecular and supramolecular transformations of wheat endosperm biopolymers during bread-making, and their implications to fabricate self-standing films from stale white bread. A reduction in the Mw of amylopectin (51.8 × 106 vs 425.1 × 106 g/mol) and water extractable arabinoxylans WEAX (1.79 × 105 vs 7.63 × 105 g/mol), and a decrease in amylose length (245 vs 748 glucose units) was observed after bread-baking. The chain length distribution of amylopectin and the arabinose-to-xylose (A/X) ratio of WEAX remained unaffected during bread-making, suggesting that heat- or/and shear-induced chain scission is the mechanism responsible for molecular fragmentation. Bread-making also resulted in more insoluble cell wall residue, featured by water unextractable arabinoxylan of lower A/X and Mw, along with the formation of a gluten network. Flexible and transparent films with good light-blocking performance (<30 % transmittance) and DPPH-radical scavenging capacity (~8.5 %) were successfully developed from bread and flour. Bread films exhibited lower hygroscopicity, tensile strength (2.7 vs 8.5 MPa) and elastic modulus (67 vs 501 MPa) than flour films, while having a 6-fold higher elongation at break (10.0 vs 61.2 %). This study provides insights into the changes in wheat biopolymers during bread-making and sets a precedent for using stale bread as composite polymeric materials.

Effects of cereal flour types and sourdough on dough physicochemical properties and steamed bread quality

Coarse cereals have been promoted for their health benefits, and sourdough is used to improve their steamed bread sensory acceptance. However, grains vary in dough physiochemical properties and steamed bread-making performance. This study investigated the effects of yeast and sourdough fermentation on the biochemical, textural, and flavor properties of dough and steamed bread of eight grain types. Results indicated that sourdough dough had a lower pH and higher total titrable acidity compared with yeast group. The texture of sourdough-steamed bread was significantly improved with reduced hardness and enhanced springiness. Microstructure revealed that sourdough resulted in starch surface corrosion and less amylopectin recrystallization. Aldehydes, alcohols, and esters are more dominant in sourdough group than yeast group. Foxtail millet and sorghum steamed breads exhibited the highest performances in texture, flavor, and sensory evaluation. This could provide a theoretical basis for producing coarse cereal products with desirable quality.

Mitigation of acrylamide formation in wood oven baked pizza base using wholemeal and refined wheat flour with low free asparagine content: considerations on fibre intake and starch digestibility

BACKGROUND

In wheat-derived bakery products, the quantity of free asparagine (fAsn) has been identified as a key factor in acrylamide (AA) formation. Based on this assumption, four varieties of common wheat (Triticum aestivum L.), Stromboli, Montecarlo, Sothys and Cosmic, selected for their different fAsn content inside the grain, were studied to evaluate their potential in the production of pizza with reduced AA levels. To this purpose, wholemeal and refined flours were obtained from each variety.

RESULTS

The fAsn content ranged from 0.25 to 3.30 mmol kg-1, with higher values for wholemeal flours which also showed greater amount of ash, fibre and damaged starch than refined wheat flours. All types of flours were separately used to produce wood oven baked pizza base, according to the Traditional Speciality Guaranteed EU Regulation (97/2010). AA reduction in the range 47-68% was found for all the selected wheat cultivars, compared with a commercial flour, with significantly lower values registered when refined flour was used. Moreover, refined leavened dough samples showed decreased levels of fAsn and reducing sugars due to the fermentation activity of yeasts. Furthermore, it was confirmed that pizza made with wholemeal flours exhibited lower rapidly digestible starch (RDS) and rapidly available glucose (RAG) values compared to that prepared with the refined flour.

CONCLUSION

This study clearly shows that a reduced asparagine content in wheat flour is a key factor in the mitigation of AA formation in pizza base. Unfortunately, at the same time, it is highlighted how it is necessary to sacrifice the beneficial effects of fibre intake, such as lowering the glycaemic index, in order to reduce AA. © 2024 Society of Chemical Industry.

Toxicity, metabolism, and mitigation strategies of acrylamide: a comprehensive review

Acrylamide, a food-borne chemical toxicant, has raised global concern in recent decades. It mainly originated from reducing sugar and free amino acid interactions in the carbohydrate-rich foodstuffs heated at high temperatures. Due to the neurotoxicity and carcinogenicity of AA, the mechanism of formation, toxic effects on health, and mitigation strategies, including conventional approaches and innovative technologies, have been of great interest since its discovery in food. Potato products (especially French fries and crisps), coffee, and cereals(bread and biscuit) are renowned contributors to AA's daily intake. The best preventive methods discussed in the literature include time/temperature optimization, blanching, enzymatic treatment, yeast treatment, additives, pulsed electric fields, ultrasound, vacuum roasting, air frying, and irradiation, exhibiting a high efficacy in AA elimination in food products.

Processing parameters in breadmaking and bioaccessibility of acrylamide and 5-hydroxymethylfurfural

This study aimed to evaluate the fate in digestive steps, bioaccessibility and diffusion of acrylamide (AA) and 5-Hydroxymethylfurfural (5-HMF) in bread samples produced under different processing parameters. AA and 5-HMF were determined in every sample ready-to-eat, after every digestion step and in the digested after crossing the dialysis membrane. The contaminants were extracted by QuEChERS method and determined by HPLC-PDA. Doubling fermentation time (from 60 to 120 min) increased the level of AA by 1.2-fold, and it decreased the level of 5-HMF by 1.4-fold. A combination of 60 min fermentation and 20 min baking led to the lowest levels of AA (1.71 mg/kg) and 5-HMF (0.50 mg/kg). There was no increase in AA level in the gastric stage however, the 5-HMF level increased. Both contaminant levels had increased in the intestinal stage. This fact showed that the determination of the contaminants in the ready-to-eat product did not reflect their actual bioaccessibility because the digestive enzymes and pH variation may affect the release and detection of AA and 5-HMF accumulated in the baking stage. The initial levels of 5-HMF were correlated to the baking time, and initial levels of AA were correlated to the fermentation time. From the bioaccessible levels of AA and 5-HMF, approximately 90 % (5 mg/kg) and 100 % (6.5 mg/kg) crossed the dialysis membrane respectively. Initial and bioaccessible levels of AA were above the security recommendations for bread (50 µg/kg), which is a concern considering the daily consumption of this food. This study showed that focusing on a combination of processing parameters could be a promising strategy to decrease the bioaccessibility of both contaminants in bread.

A chestnut-hemp type-II sourdough to improve technological, nutritional, and sensory properties of gluten-free bread

The nutritional quality of gluten-free (GF) products is usually improved by using flours derived from alternative grains (e.g., pseudocereals and legumes), additives and hydrolysates, leading to long ingredient lists in the labels, that conflict with current customer expectations. In this work, chestnut, carob, and hemp flours were used as mixed ingredients for making a gluten-free type-II sourdough. Three exopolysaccharides-producer lactic acid bacteria, belonging to Leuconostoc mesenteroides, Weissella cibaria, and Leuconostoc pseudomesenteroides, were used, and the fermentation processes (6 log10 cfu/g, 25 °C, 16 h) optimize to maximize the EPS synthesis (15.70 ± 2.1 mg/kg). The chestnut-hemp (70:30) type-II sourdough was included in a rice/corn gluten-free bread recipe also containing psyllium flour as structuring agent. Although the fortification with unfermented flours already led the achievement of 6 g/100 g of fiber (high fiber, Regulation EC n. 1924/2006) and content of magnesium higher than the daily reference intakes, the use of type-II sourdoughs led to a further structural, sensory, and nutritional improvements (e.g., decreasing the main anti-nutritional factor phytic acid). This work demonstrated that the use of ad-hoc selected ingredients and optimized protocol can be used to produce a GF and "clean label" bread with optimal nutritional features and appreciable sensory and structural properties.

Toxicity, formation, contamination, determination and mitigation of acrylamide in thermally processed plant-based foods and herbal medicines: A review

Thermal processing is one of the important techniques for most of the plant-based food and herb medicines before consumption and application in order to meet the specific requirement. The plant and herbs are rich in amino acids and reducing sugars, and thermal processing may lead to Maillard reaction, resulting as a high risk of acrylamide pollution. Acrylamide, an organic pollutant that can be absorbed by the body through the respiratory tract, digestive tract, skin and mucous membranes, has potential carcinogenicity, neurological, genetic, reproductive and developmental toxicity. Therefore, it is significant to conduct pollution determination and risk assessment for quality assurance and security of medication. This review demonstrates state-of-the-art research of acrylamide focusing on the toxicity, formation, contamination, determination, and mitigation in taking food and herb medicine, to provide reference for scientific processing and ensure the security of consumers.

Impact of Some Enzymatic Treatments on Acrylamide Content in Biscuits

Since its discovery in many heat-treatment foods in 2002, many efforts have been made to reduce acrylamide levels in foods. Methods to reduce acrylamide levels by reducing Maillard reaction products have been considered. However, baking cookies produces acrylamide, a carcinogenic compound. This study aimed to use a new quantitative index and formula for L-asparaginase, glucose oxidase, their 1:1 blending enzymes, baker’s yeast, and green tea powder (0.5 g/kg wheat flour) at a new proposed temperature of 37 °C for 30 min to reduce acrylamide production in biscuits and bakery products using new indicators such as asparagine reduction (%), the asparagine/acrylamide ratio, acrylamide reduction (%), and the asparagine/reducing sugar ratio. The highest acrylamide concentrations were reduced from 865 mg/kg in the blank sample (BT0) to 260 and 215 mg/kg in the mixed enzyme powder (1:1) (BT3)- and BT4-treated samples, respectively. The biscuit samples treated with 0.5 g/kg L-asparaginase reduced the acrylamide levels by approximately 67.63%, while the BT3 samples showed acrylamide levels of 69.94% and asparagine levels of 68.75% and 47%, respectively, compared with percentage in the untreated sample (blank), 95%. This percentage was 54.16% for the BT4 samples. The results showed that acrylamide was formed during baking, and all treatment samples inhibited its formation, making it possible to produce foods with low levels of acrylamide in starchy foods in the food industry at 37 °C for 30 min and preserving the quality and nutritional value of the final product. It can be used as a specialty food or functional food and protects school-agechildren, as well as youth on campus, from approximately 70–80% of their daily intake of acrylamide.

Study of Physico-Chemical Properties of Dough and Wood Oven-Baked Pizza Base: The Effect of Leavening Time

The research objective was to investigate the morpho-rheological, chemical, and structural changes of dough and Neapolitan pizza TSG as the leavening time varies and to evaluate their effects on the digestibility of starch and on the formation of acrylamide during baking. Pizza dough leavening was monitored for 48 h at 22 °C/80% RH, and the analyses were conducted at selected leavening times (0, 4, 8, 16, 24, and 48 h). It was observed that in 30 h the volume tripled and the viscoelastic dough relaxed in the first 4 h, as evidenced by the lower value of the relaxation percentage “a” and the higher rate of decay “b”, associated with a high value of the compression work, indicating the presence of a very strong gluten mesh. In the following hours, the dough lost elasticity, and in fact, the G’ modulus decreased due to the weakening of the weak interactions between the gluten proteins and the starch. This suggests that a long leavening improved the extensibility of the pizza disc, facilitating the action of the pizza maker. Thermal (TGA and DSC) and morphological (SEM) analyses evidenced the highest water removal rate from the dough, a wider starch gelatinization temperature range, a ∆H of 0.975 ± 0.013 J/g, and a more open and weak gluten structure in dough balls leavened for 16 h. As the leavening time increased, both dough and pizza base samples showed an increase in reducing sugars and free amino groups, while the rapidly digestible starch decreased in the dough following the metabolism of the yeasts and increased in the pizza base due to the starch gelatinization that occurs during baking, which makes it much more susceptible to α-amylase. Finally, the levels of acrylamide remained at the same values despite the higher availability of reducing sugars and its precursors during leavening.

Highland Barley Starch: Structures, Properties, and Applications

Highland barley (HB) is a nutritious crop with excellent health benefits, and shows promise as an economically important crop with diverse applications. Starch is the main component of HB and has great application potential owing to its unique structural and functional properties. This review details the latest status of research on the isolation, chemical composition, structure, properties, and applications of highland barley starch (HBS). Suggestions regarding how to better comprehend and utilize starches are proposed. The amylopectin content of HBS ranged from 74% to 78%, and can reach 100% in some varieties. Milling and air classification of barley, followed by wet extraction, can yield high-purity HBS. The surface of HBS granules is smooth, and most are oval and disc-shaped. Normal, waxy, and high-amylose HBS have an A-type crystalline. Due to its superb freeze-thaw stability, outstanding stability, and high solubility, HBS is widely used in the food and non-food industries. The digestibility of starch in different HB whole grain products varies widely. Therefore, the suitable HB variety can be selected to achieve the desired glycemic index. Further physicochemical modifications can be applied to expand the variability in starch structures and properties. The findings provide a thorough reference for future research on the utilization of HBS.

Crickets (Acheta domesticus) as Wheat Bread Ingredient: Influence on Bread Quality and Safety Characteristics

The aim of this study was to assess respondents' opinions on the choice of edible insects as a food, and to evaluate the influence of cricket flour (ECF) (10, 20, 30%) on the quality of wheat bread (WB). Whereas ECF is an additional source of acrylamide precursors, in order to reduce acrylamide formation in WB, fermentation of ECF with Lactiplantibacillus plantarum-No.122 was applied. It was established that 70.7% of the respondents had never eaten insects and more than 30% would not choose them. However, ECF was suitable substrate for fermentation (lactobacilli count 8.24 log₁₀CFU/g, pH-4.26). In addition, fermentation reduced the total biogenic amines content in ECF (by 13.1%). The highest specific volume showed WB, prepared with fermented ECF (10, 20, 30%). All the tested WB showed similar overall acceptability (on average, 7.9 points). However, the highest intensity of emotion "happy" was induced by the WB, prepared with fermented ECF. Most of the WB with non-treated and fermented ECF showed higher acrylamide concentration (except WB with 10% of fermented ECF), in comparison with the control. Finally, fermentation is recommended for ECF inclusion in the main WB formula because fermentation improves not only quality but also reduces acrylamide concentration in WB.

Chemical Contamination in Bread from Food Processing and Its Environmental Origin

Acrylamide (AA), furan and furan derivatives, polycyclic aromatic amines (PAHs), monochloropropanediols (MCPDs), glycidol, and their esters are carcinogens that are being formed in starchy and high-protein foodstuffs, including bread, through baking, roasting, steaming, and frying due to the Maillard reaction. The Maillard reaction mechanism has also been described as the source of food processing contaminants. The above-mentioned carcinogens, especially AA and furan compounds, are crucial substances responsible for the aroma of bread. The other groups of bread contaminants are mycotoxins (MTs), toxic metals (TMs), and pesticides. All these contaminants can be differentiated depending on many factors such as source, the concentration of toxicant in the different wheat types, formation mechanism, metabolism in the human body, and hazardous exposure effects to humans. The following paper characterizes the most often occurring contaminants in the bread from each group. The human exposure to bread contaminants and their safe ranges, along with the International Agency for Research on Cancer (IARC) classification (if available), also have been analyzed.

A strategy for reducing acrylamide content in wheat bread by combining acidification rate and prerequisite substance content of Lactobacillus and Saccharomyces cerevisiae

This study mainly focused on a strategy for reducing acrylamide(AM) content in wheat breads by combining Lactobacilli and Saccharomyces cerevisiae in sourdough, in comparison with natural fermentation. The results showed that acrylamide levels in breads using sourdough were much lower (102.02-129.37 μg/kg) than control group (204.79 μg/kg). The pH value of sourdough directly influenced the formation of acrylamide in breads (P < 0.01). Furthermore, significant (P < 0.05) correlations were also found between protein and acrylamide contents. There no significant correlations were observed between acrylamide and reducing sugar contents. According to the different effects of strains, it could be concluded that the acrylamide reducing potential of strains was strain-specific, with Pediococcus pentosaceus being the most effective. This suggests that sourdough fermentation with appropriate strains can be used as an advantageous technology to reduce the acrylamide content of wheat breads.

Fermentation-Inspired Gelatin Hydrogels with a Controllable Supermacroporous Structure and High Ductility for Wearable Flexible Sensors

Supermacroporous hydrogels have attracted wide concern due to their comfort and breathability in wearable health-monitoring applications. Size controllable supermacroporous structure and excellent mechanical properties are the most important for its application. However, they are normally fabricated by the cryogelation method, which is difficult to control pore size and maintain flexibility. Here, yeast fermentation-inspired gelatin hydrogels with a controllable supermacroporous structure and excellent mechanical properties were fabricated for the first time. The pore size can be controlled by adjusting the content of glucose and yeast, the ratio of glucose to yeast, fermentation time, and gelatin content during fermentation. The hydrogels demonstrated a controllable pore size range from 100 to 400 μm and rapid swelling characteristics. The mechanical properties were maintained by soaking ammonium sulfate solution for 12 h, showing maximum tensile and compressive strains over 300 and 99%, respectively. This novel approach can be easily applied to the preparation of supermacroporous and high ductility hydrogels under mild conditions. Furthermore, conductive hydrogels combined supermacroporous structures with conductive polyaniline and reduced oxidized graphene, and silver nanowires were prepared as wearable flexible sensors. The obtained sensors maintain well-distributed porosity, breathability, and mechanical flexibility, also showing excellent conductivity of 2.4 S m-1. Finally, the sensors were successfully applied to detect physiological signals and human-computer interaction.

Effect of synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae on thermal properties of wheat bran dietary fiber-wheat starch system

A synergistic fermentation system was constructed using single strains of Lactobacillus plantarum and Saccharomyces cerevisiae cultured separately; wheat starches containing different wheat bran dietary fiber (WBDF) levels (0, 3, 6, 9 & 12%) were fermented in this system. The thermal properties of materials were measured by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and rapid viscosity analysis (RVA). The results showed that WBDF may alter the thermal behavior of starch by forming hydrogen bonds with the leached starch chains and limit the available water of starch. The viscosity properties (peak, trough, and final viscosity) and setback decreased, and they were negatively correlated with the WBDF levels. In addition, dynamic rheological measurements showed that the addition of WBDF significantly enhanced the elasticity of fermented starch gels while slightly improving the mechanical strength, and 6% level of WBDF had the largest contribution. This study provides some data for the production of high dietary fiber fermented flour products, both common and gluten-free.

Comparative study of thermo-mechanical, rheological, and structural properties of gluten-free model doughs from high hydrostatic pressure treated maize, potato, and sweet potato starches

Effects of high hydrostatic pressure (HHP, 100, 300 and 500 MPa for 30 min at 25 °C) treated maize (MS), potato (PS), and sweet potato (SS) starches on thermo-mechanical, rheological, microstructural properties and water distribution of gluten-free model doughs were investigated. Significant differences were found among starch model doughs in terms of water absorption, dough development time, and dough stability at 500 MPa. Total gas production of MS, PS and SS doughs was significantly increased from 541 to 605 mL (300 MPa), 527 to 568 mL (500 MPa) and 551 to 620 mL (500 MPa) respectively as HHP increased. HHP increased storage (G') and loss (G″) modulus in terms of rheological properties suggesting, the higher viscoelastic behavior of starch model doughs. The dough after 500 MPa treatment showed lower degree of dependence of G' on frequency sweep suggesting, the formation of a stable network structure. In addition, continuous abundant water distribution and uniform microstructure were found in MS (300 MPa), PS (500 MPa) and SS (500 MPa) doughs for 60 min fermentation. Thus, the starches after HHP show great application potential in gluten-free doughs with improved characteristics.

Effect of wheat bran dietary fiber on structural properties of wheat starch after synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae

This study investigated the changes in the structure of wheat starch after synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae at different wheat bran dietary fiber (WBDF) levels. The results showed that WBDF was slightly resistant to the decrease in acidity within the fermentation system. The amylose content decreased from 32.12% to 19.92% (P < 0.05), amylose/amylopectin ratio decreased from 0.47 to 0.25 (P < 0.05), and relative crystallinity decreased from 12.17% to 9.40% (P < 0.05) in the samples containing WBDF compared with the control. Scanning electron microscopy showed more eroded starch as the WBDF level increased. Fourier-transform infrared spectroscopy revealed a decrease in the starch-hydrogen binding absorbance in the 3600-3000 cm^-1 wavemumber; and the 1047/1022 and 995/1022 cm^-1 data indicated an increase in the degree of order and degree of double helix of the samples containing WBDF. The results of the study might help understand the interaction between dietary fibers and starch during fermentation and guide the production of fermented high-fiber flour products.

Incorporation of high fructose corn syrup with different fructose levels into biscuit: An assessment of physicochemical and textural properties

This study examined the effects of different concentrations of high-fructose corn syrup (HFCS, 28%, 44%, 55%) used in biscuit formulation on the hydroxymethyl furfural (HMF) acrylamide content, and textural properties were investigated and compared with invert sugar and sucrose-incorporated samples. No significant difference in the chemical composition (moisture, fat, protein, and ash) among different samples was noted based on the results. The highest L* was associated with a control sample containing sugar and invert sugar, although an increase in F55 content decreased the L* value significantly (p < .05). The highest hardness value was correlated with control samples (6.5 N), although the sample with 12.5% F42 and 25% F55 demonstrated lower hardness 6.27 N, and the lowest hardness value (3.97 N) was related to the sample containing 12.5% F42 and 25% F28. The amounts of water activity of all samples were in the range of 0.22 to 0.29, with the highest amount related to the control sample. The SEM images showed a uniform surface with several holes for all the biscuits. The highest and lowest (HMF) levels were related to the samples containing 25% F55 (46.04) and 12.5% F42 with 2.36 ppm. The control sample with the acrylamide amount of 28.50 ppb and the sample containing 12.5% F42 and 25% F55 with the acrylamide amount of 27.33 ppb showed the highest acrylamide content.

Impacts of Hydrothermal Treatments on the Morphology, Structural Characteristics, and In Vitro Digestibility of Water Caltrop Starch

The influence of hydrothermal treatments on the structural properties and digestibility of water caltrop starch was investigated. Scanning electron microscopy (SEM) showed some small dents on the surface of starch granules for samples treated with heat moisture treatment (HMT), but not for samples treated with annealing (ANN) which generally showed smoother surfaces. The gelatinization temperature of starch was generally increased by hydrothermal treatments, accompanied by a trend of decreasing breakdown viscosity. These results implied the improvement of thermal and shearing stability, particularly for HMT in comparison to ANN. After being cooked, the native and ANN-modified water caltrop starch granules were essentially burst or destroyed. On the other hand, the margin of starch granules modified by HMT and dual hydrothermal treatments remained clear with some channels inside the starch granules. X-ray diffraction revealed that the crystalline pattern of water caltrop starch changed from the CA-type to the A-type and the relative crystallinity reduced with increasing moisture levels of HMT. Results of ANN-modified water caltrop starch were mostly similar to those of the native one. Moreover, water caltrop starch modified with HMT20 and dual modification contained a pronouncedly higher resistant starch content. These results suggested that HMT, ANN, and dual modification effectively modified the functional properties of water caltrop starch.

Acrylamide in Bakery Products: A Review on Health Risks, Legal Regulations and Strategies to Reduce Its Formation

Acrylamide is a contaminant as defined in Council Regulation (EEC) No 315/93 and as such, it is considered a chemical hazard in the food chain. The toxicity of acrylamide has been acknowledged since 2002, among its toxicological effects on humans being neurotoxicity, genotoxicity, carcinogenicity, and reproductive toxicity. Acrylamide has been classified as carcinogenic in the 2A group, with human exposure leading to progressive degeneration of the peripheral and central nervous systems characterized by cognitive and motor abnormalities. Bakery products (bread, crispbread, cakes, batter, breakfast cereals, biscuits, pies, etc.) are some of the major sources of dietary acrylamide. The review focuses on the levels of acrylamide in foods products, in particular bakery ones, and the risk that resulting dietary intake of acrylamide has on human health. The evolving legislative situation regarding the acrylamide content from foodstuffs, especially bakery ones, in the European Union is discussed underlining different measures that food producers must take in order to comply with the current regulations regarding the acrylamide levels in their products. Different approaches to reduce the acrylamide level in bakery products such as the use of asparginase, calcium salts, antioxidants, acids and their salts, etc., are described in detail.

Acrylamide in bread: a review on formation, health risk assessment, and determination by analytical techniques

Acrylamide is a water-soluble toxicant found in high-protein and carbohydrate-containing foods exposed to high temperature like bread as the staple foodstuff. This toxicant is mainly formed via Maillard reaction. The potential adverse effects of acrylamide especially possible carcinogenicity in human through dietary exposure necessitate its monitoring. Regarding the existence of its precursors in wheat bread formulation as well as extreme consumption of bread by most population and diversity of bread types, its acrylamide level needs to be investigated. The indicative value for acrylamide in wheat bread is set at 80 μg/kg. Consequently, its determination using liquid chromatography-tandem mass spectrometry (LC-MS/MS), gas chromatography-mass spectrometry (GC-MS), or capillary electrophoresis can be helpful considering both the risk assessment and quality control aspects. In this respect, methods based on LC-MS/MS show good recovery and within laboratory repeatability with a limit of detection of 3-20 μg/kg and limit of quantification of 10-50 μg/kg which is suitable for the immediate requirements for food product monitoring and calculation of consumer exposure.

Simultaneously Mitigation of Acrylamide, 5-Hydroxymethylfurfural, and Oil Content in Fried Dough Twist via Different Ingredients Combination and Infrared-Assisted Deep-Frying

The effect of main ingredients (wheat flours, polyol sweeteners, and frying oil) and infrared-assisted deep-frying on the acrylamide, 5-hydroxymethylfurfural (HMF), oil content, and physicochemical characteristics of fried dough twist (FDT) were investigated. The amount of acrylamide and HMF produced in FDT made with low-gluten flour is significantly lower than that of flour with high gluten content. Among polyol sweeteners, maltitol causes the greatest reduction in acrylamide and HMF in FDT. Moreover, the oil content of FDT was significantly reduced by optimizing the infrared-assisted deep-frying process. At last, compared with deep-frying FDT made of sucrose, infrared-assisted deep-frying FDT made of maltitol reduced acrylamide, HMF, and oil content by 61.8%, 63.4%, and 27.5%, respectively. This study clearly showed that the ingredients, flour and polyol sweeteners used to process FDT are the two major determinants of the formation of acrylamide and HMF in FDT, and infrared-assisted deep-frying can significantly affect the oil content in FDT. Simultaneously, the mitigation of the acrylamide, HMF, and oil content in FDT can be achieved by using low-gluten flour and maltitol in the ingredients, combined with infrared-assisted deep-frying.

Comprehensive Study on the Acrylamide Content of High Thermally Processed Foods

Acrylamide (AA) formation in starch-based processed foods at elevated temperatures is a serious health issue as it is a toxic and carcinogenic substance. However, the formation of more AA entangles with modern-day fast food industries, and a considerable amount of this ingredient is being consumed by fast food eaters inadvertently throughout the world. This article reviews the factors responsible for AA formation pathways, investigation techniques of AA, toxicity, and health-related issues followed by mitigation methods that have been studied in the past few decades comprehensively. Predominantly, AA and hydroxymethylfurfural (HMF) are produced via the Maillard reaction and can be highlighted as the major heat-induced toxins formulated in bread and bakery products. Epidemiological studies have shown that there is a strong relationship between AA accumulation in the body and the increased risk of cancers. The scientific community is still in a dearth of technology in producing AA-free starch-protein-fat-based thermally processed food products. Therefore, this paper may facilitate the food scientists to their endeavor in developing mitigation techniques pertaining to the formation of AA and HMF in baked foods in the future.

Effects of thermal properties and behavior of wheat starch and gluten on their interaction: A review

Starch and gluten, the most important macromolecules in wheat flour, vary in thermal properties. The thermal behavior of starch, gluten and their complexes during the manufacture and quality control of flour products need to be accurately understood. However, the high complexity of starch-gluten systems impedes the accurate description of their interactions. When heated within varying temperature ranges and when water molecules are involved, the behaviors of amylose and amylopectin change, and the properties of the starch are modified. Moreover, important indicators of starch granules such as gelatinization temperature, peak viscosity, and so on, which are encapsulated by the gluten matrix, are altered. Meanwhile, the high-temperature environment induces the opening of the intrachain disulfide bonds of gliadin, leading to an increase in the probability of interchain disulfide bond formation in the gluten network system. These behaviors are notable and may provide insights into this complex interaction. In this review, the relationship between the thermal behavior of wheat starch and gluten and the quality of flour products is analyzed. Several methods used to investigate the thermal characteristics of wheat and its flour products are summarized, and some thermal interaction models of starch and gluten are proposed.

Physicochemical properties and in vitro digestibility of hydrothermal treated Chinese yam (Dioscorea opposita Thunb.) starch and flour

The objective of this study was to investigate the effects of hydrothermal treatments (heat-moisture treatment (HMT) and annealing (ANN)) on the physicochemical properties and in vitro digestibility of yam starch and yam flour. Hydrothermal treatments decreased the pasting properties of yam starch and yam flour. Compared with yam starch, HMT significantly (p < 0.05) reduced the pasting viscosities of yam flour. Both HMT and ANN caused an increase of the gelatinization temperatures (T_o, T_p, and T_c) and a decrease of enthalpy (△H). The increasement in ratio of 1047/1022 cm^-1 and 995/1022 cm^-1 suggested that HMT and ANN resulted in an increase in short-range order. The crystalline pattern of all samples was still A-type, and HMT yam starch exhibited higher crystallinity (26.20%). The most significant inhibition of in vitro digestibility was found in HMT yam flour, with slowly digestible starch and resistant starch contents increasing by 3.73% and 4.40%, respectively. Hydrothermal treatments made the no-starch ingredients in yam flour agglomerate and adhere to starch granules. Confocal laser scanning microscopy showed that the starch being coated or embedded by protein was a possible reason for the differences in physicochemical properties and in vitro digestibility between yam starch and yam flour.

Association of asparagine concentration in wheat with cultivar, location, fertilizer, and their interaction

The need to produce wheat with low asparagine concentration is of great importance as a measure to mitigate acrylamide concentration in wheat-based products. The association of asparagine concentration in Canadian bread wheat with cultivar, growing location, fertilizer and their interaction were investigated. Wheat cultivars (8) were grown in 2 locations under 4 fertilizer treatments in triplicate (which consisted of two nitrogen rates (90 or 120 lbs/acre) with or without 15 lbs sulphur per acre). The asparagine concentration ranged from 168.9 to 1050 µg/g and was significantly affected by cultivar, location, and their interaction but not fertilizer treatment. Location and cultivar were responsible for 80% and 14% of the variation, respectively. Some cultivars were not affected by location and maintained their low asparagine accumulation trait. Thus, breeding strategies should aim to identify cultivars that are low asparagine accumulating and are stable across different growing environments.

Formation and Alterations of the Potentially Harmful Maillard Reaction Products during the Production and Storage of Brown Fermented Milk

To improve the quality and safety of brown fermented milk (BFM), the formation and alterations of potentially harmful Maillard reaction products (MRPs), including 3-deoxyglucosone (3-DG), methylglyoxal (MGO), 5-(hydroxymethyl)-2-furfural (HMF), acrylamide and flavour components were investigated during the browning, fermentation and commercial storage. MRPs were shown to be produced mainly during the browning stage. The levels of different substances varied during the fermentation and commercial storage stage. The proportion and type of carboxylic acids in the flavour components significantly increased during the fermentation stage. Browning index of milk during the browning stage was shown to be positively associated with the 3-DG (Pearson's r = 0.9632), MGO (Pearson's r = 0.9915), HMF (Pearson's r = 0.9772), and acrylamide (Pearson's r = 0.7910) levels and the total percentage of the flavour components from four different categories (Pearson's r = 0.7407). Changes in physicochemical properties of BFM during production not only contribute to predict the formation of potentially unhealthy MRPs, but also Lactobacillus species used for the fermentation should be carefully selected to improve the quality of this product.

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.

Effects of Maillard Reaction Products on Sensory and Nutritional Qualities of the Traditional French Baguette

The goals of this study were to evaluate the effect of baking time on the Maillard reaction products (MRPs) generated in the crust of the traditional French baguette and to estimate their impact on its sensory characteristics, its acrylamide content, and its bifidogenic effect. Melanoidins, volatile compounds, and acrylamide were evaluated in the crust of traditional French baguettes baked between 12 and 22 min at 225 °C. The increase in melanoidins was positively correlated to the baking time, while volatile compounds only increased until 18 min. The acrylamide content was estimated to be below 18 μg/kg, which confirms the findings of EFSA that bread is not a main contributor to dietary acrylamide. A descriptive sensory analysis showed that the baking time positively affected the sensory quality of the crust. The consumer test revealed the same trend and the panelists favorably judged the well-baked baguettes based on a better crust flavor and crispness. The bifidogenic effect of the crust and the crumb from the baguettes baked 22 min was evaluated on the in vitro growth of Bifidobacterium adolescentis. The results demonstrated that the crumb and the crust had exactly the same bifidogenic impact, therefore not caused by melanoidins.

PRACTICAL APPLICATION

The consumption of bread in France has decreased since 2007, although bread is considered by French people as "healthy" and essential to maintain a balanced diet. The current study evaluated the global qualities of the French baguette in order to highlight its high sensory quality and its beneficial effect by inducing a possible growth of bifidobacteria, even in well-baked baguettes. These findings allow the French bakery industry to develop an argument to promote its technical know-how and to help consumers choose healthier and tastier bread. Moreover, this study provided some recommendations of baking processes to maintain a high sensory quality of the French baguette and limit the formation of undesirable compounds, such as acrylamide, in the crust.