Acrylamide in food: mechanisms of formation and influencing factors during heating of foods

Processing and preservation technologies to enhance indigenous food sovereignty, nutrition security and health equity in North America

Indigenous foods are carriers of traditional native North American food culture and living philosophy. They are featured by the wide varieties in fresh and processed forms, richness in nutrition, flavor, health benefits and diversity in origins, but are usually misunderstood or underrepresented in the modern food systems. Conventional processing and cooking methods are sometimes labor-intensive, less efficient and lack science-based guidelines to prevent unseen safety risks and food loss. Global and regional climate change have caused additional challenges to conventional cooking/processing, and increased native communities' reliance on externally produced foods, which have resulted in increasing nutritional unbalance and prevalence of diet-related health issues. Current and emerging technologies, such as storage and packaging, drying, safety processing, canning, pickling, and fermentation, which treat foods under optimized conditions to improve the safety and extend the shelf-life, are increasingly used in current food systems. Therefore, exploring these technologies for indigenous foods offers opportunities to better preserve their nutrition, safety, and accessibility, and is critical for the sovereignty and independence of indigenous food systems, and sustainability of indigenous food culture. This mini-review focuses on identifying adoptable processing and preservation technologies for selected traditional indigenous foods in North America, summarizing education, extension, and outreach resources and discussing the current challenges and future needs critical to expanding knowledge about indigenous foods and improving food sovereignty, nutrition security, and health equity.

The Antioxidant Potential of Various Wheat Crusts Correlates with AGE Content Independently of Acrylamide

Epidemiological studies have indicated that the consumption of whole-grain products is associated with a reduced risk of cardiovascular diseases, type II diabetes, and cancer. In the case of bread, high amounts of antioxidants and advanced glycation end products (AGEs) are formed during baking by the Maillard reaction in the bread crust; however, the formation of potentially harmful compounds such as acrylamide also occurs. This study investigated the antioxidant responses of different soluble extracts from whole-grain wheat bread crust extracts (WBCEs) in the context of the asparagine, AGE, and acrylamide content. For that, we analyzed nine bread wheat cultivars grown at three different locations in Germany (Hohenheim, Eckartsweier, and Oberer Lindenhof). We determined the asparagine content in the flour of the 27 wheat cultivars and the acrylamide content in the crust, and measured the antioxidant potential using the induced expression of the antioxidant genes GCLM and HMOX1 in HeLa cells. Our study uncovered, for the first time, that the wheat crust's antioxidant potential correlates with the AGE content, but not with the acrylamide content. Mass spectrometric analyses of WBCEs for identifying AGE-modified proteins relevant to the antioxidant potential were unsuccessful. However, we did identify the wheat cultivars with a high antioxidant potential while forming less acrylamide, such as Glaucus and Lear. Our findings indicate that the security of BCEs with antioxidative and cardioprotective potential can be improved by choosing the right wheat variety.

Strain improvement, artificial intelligence optimization, and sensitivity analysis of asparaginase-mediated acrylamide reduction in sweet potato chips

In recent times, L-asparaginase has emerged as a potential anti-carcinogen through hydrolysis of L-asparagine in the blood for anti-leukemic application, and in carbohydrate-based foods, for acrylamide reduction applications. In this study, Aspergillus sydowii strain UCCM 00124 produced an L-asparaginase with a baseline acrylamide reduction potential of 64.5% in sweet potato chips. Plasma mutagenesis at atmospheric pressure and room temperature (ARTP) was employed to improve L-asparaginase production while artificial neural network embedded with genetic algorithm (ANN-GA) and global sensitivity analysis were used to identify and optimize process conditions for improved acrylamide reduction in sweet potato chips. The ARTP mutagenesis generated a valine-deficient mutant, Val-Asp-S-180-L with 2.5-fold L-asparaginase improvement. The ANN-GA hybrid evolutionary intelligence significantly improved process efficiency to 98.18% under optimized conditions set as 118.6 °C, 726.37 g/L asparagine content, 9.92 µg/mL L-asparaginase, 4.54% NaCl, and soaking time of 15 h without significant changes in sensory properties. The sensitivity index revealed initial asparagine content as the most sensitive parameter to the bioprocess. The enzyme demonstrated significant thermo-stability with Arrhenius deactivation rate constant, Kd, of 0.00562 min-1 and half-life, t1/2, of 123.35 min at 338 K. These conditions are recommended for sustainable healthier, and safer sweet potato chips processing in the food industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05757-5.

Evaluating the effect of alpha-mangostin on neural toxicity induced by acrylamide in rats

Acrylamide (ACR) is known to be a neurotoxic agent for humans and animals that has many applications in industry. Alpha-mangostin is a natural antioxidant that is extracted from mangosteen. This study aimed to investigate the protective effects of alpha-mangostin against ACR-induced neurotoxicity in rats and PC12 cells. Male Wistar rats were used in this investigation for 11 days, divided into 8 groups: 1. control group (normal saline), 2. ACR (50 mg/kg, i.p.), 3-6. ACR + alpha-mangostin (20, 40, 60 mg/kg, p.o.), 7. ACR + vitamin E (200 mg/kg, i.p., every other day) 8. alpha-mangostin (60 mg/kg, p.o.). On the last day of the study, the behavioral test was performed. The amounts of malondialdehyde (MDA) and glutathione (GSH) were measured. Also, the effects of ACR and alpha-mangostin were assessed by MTT assay on PC12 cells, and the levels of reactive oxygen species (ROS), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved caspase-3 proteins were measured by Western blotting. Receiving ACR caused motor disorders in animals, increased MDA, and decreased GSH levels of the cerebral cortex versus the control group. Alpha-mangostin (60 mg/kg) reduced ACR motility disorders, MDA amounts, and augmented GSH levels. The concurrent administration of vitamin E and ACR reduced gait score, MDA level, and amplified GSH content versus the ACR group. In the in vitro section, alpha-mangostin (1.25 µM, 24 h) increased cell viability, attenuated ROS, Bax/Bcl-2, and cleaved caspase-3 levels versus the ACR group. Alpha-mangostin reduced the toxicity of ACR by inhibiting oxidative stress and apoptosis. Therefore, it could be a promising compound for managing ACR-induced neurotoxicity.

Effect of Preliminary Treatment by Pulsed Electric Fields and Blanching on the Quality of Fried Sweet Potato Chips

The effects of pulsed electric fields (PEF) and blanching pretreatments on frying kinetics, oil content, color, texture, acrylamide (AA) content, and microstructure have been investigated in this paper. The total PEF pretreatment duration was t_PEF = 0.2 s with an intensity of E = 1 kV/cm; blanching was studied at 85 °C for 5 min. The results demonstrated that pretreatment significantly reduced the moisture ratio and oil content by 25% and 40.33%, respectively. The total color change ΔE value of the pretreated samples was lower than that of the untreated samples. In addition, pretreatment increased the hardness of the sample after frying, and the AA content in the fried samples pretreated with PEF + blanching was reduced by approximately 46.10% (638 μg/kg). Finally, fried sweet potato chips obtained by the combined pretreatment exhibited a smoother and flatter cross-sectional microstructure.

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.

Quercetin ameliorates acute acrylamide induced spleen injury

Acrylamide is used for industrial and laboratory purposes; it also is produced during cooking of carbohydrate-rich food at high temperature. We investigated the therapeutic potential of quercetin for treatment of acute acrylamide induced injury to the spleen. We used female albino rats treated with acrylamide for 10 days followed by oral administration of quercetin in three doses for 5 days. We observed significantly reduced total body weight, spleen weight, red blood cells, total proteins, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phophate dehydrogenase, reduced glutathione, concentration of serum IgG and IgM after acrylamide induced toxicity compared to controls. We also found that white blood cells, triglycerides, cholesterol and lipid oxidation were increased significantly after acrylamide induced toxicity in rats compared to controls. Histoarchitecture of spleen was affected adversely by acrylamide toxicity. Administration of quercetin ameliorated adverse effects of acrylamide in a dose-dependent manner. Quercetin appears to ameliorate acrylamide induced injury to the spleen by increasing endogenous antioxidants and improving histoarchitecture and immune function.

Mitigation of Acrylamide Content in Biscuits through Combined Physical and Chemical Strategies

Acrylamide in biscuits represents a major concern. This research work was aimed at modifying the current formulation of biscuits to reduce the acrylamide content while maintaining the chemical, physical, and sensory characteristics of the original product. A strategy based on the FoodDrinkEurope Acrylamide Toolbox was adopted. The content of the leavening agent ammonium bicarbonate, the baking temperature program, and the time duration of steam released during the baking process were the three factors evaluated through a factorial design of experiment. The partial replacement of ammonium bicarbonate (from 9.0 g to 1.5 g per 500 g of flour) with sodium bicarbonate (from 4.5 g to 12.48 g), lowering of the temperature in the central phase of the baking process (from 170 °C to 150 °C), and the release of steam for 3 min resulted in an 87.2% reduction in acrylamide concentration compared to biscuits of reference. CIELab color indices and a_w were the parameters that showed the most significant correlation with acrylamide concentration in biscuits and could, therefore, become markers to predict the acrylamide content along production lines for an instant evaluation.

Mitigation of Acrylamide in Potato Chips by Pre-drying and Pulsed Electric Field Treatment

The object of this work was to study the effects of preliminary vacuum drying (VD), pulsed electric field (PEF) treatment, frying temperature on color, oil uptake, and acrylamide (AA) content in fried potato chips. The results of this study indicated that an increase of frying temperature from 120 to 180°C led to a decrease of frying time of around 70% for untreated and PEF pre-treated samples. The color value of L* and a* decreased with the increase of frying temperature, and those values of the sample pre-treated by PEF were significantly higher compared to those obtained from untreated samples. The PEF pre-treatment promoted the reduction of oil content of fried samples by up to 17.6, 14.2, and 16% compared with untreated samples at the frying temperatures of 120, 150, and 180°C, respectively. Higher efficiency was observed by applying the preliminary VD in the case of the frying temperature of 150°C. Furthermore, it was revealed that PEF pre-treatment and preliminary VD application lead to a synergetic effect on the reduction of AA content in potato chips. For example, with the initial moisture ratio of 0.5, pre-dried by VD and pre-treated by PEF, the AA content was noticeably decreased from 2,220 to 311 μg/kg compared to untreated and undehydrated samples at the frying temperature of 150°C. Our findings provide reference for a new pre-treatment to mitigate AA formation and to improve the quality of potato chips.

The analysis and probabilistic health risk assessment of acrylamide level in commercial nuggets samples marketed in Iran: effect of two different cooking methods

The aim of current study was to evaluate the acrylamide level in chicken, meat and shrimp nugget samples cooked in both traditional and industrial methods using "Quick, Easy, Cheap, Effective, Rugged, and Safe" QuEChERS extraction and gas chromatography-flame-ionization detection (GC-FID). Results revealed the traditional frying method has significant effect on the increase of acrylamide compared to industrial frying method and it was also found that the different cooking temperatures and time have significant effect on increase of acrylamide formation (p < 0.05), but type of edible oils had no significant effect. The highest acrylamide level found in shrimp nuggets (27 ± 1.5 ng/g) which fried by colza oil and traditional cooking method (6 min at 220 °C), while the lowest content of acrylamide found in chicken nuggets (7.3 ± 0.1 ng/g) which fried by corn oil and industrial method (3 min at 180 °C). Monte Carlo simulation (MCS) results indicated that the trend of potential non-carcinogenic risks on THQ for children was chicken nugget (3.51E-3) > meat nugget (1.36E-3) > shrimp nugget (1.43E-4) and for adults was chicken nugget (3.49E-4) > meat nugget (1.35E-4) > shrimp nugget (1.38E-5). The health risk of acrylamide for adults and children, was considerably lower than the safe risk limits (HQ >1 and CR > 1E-4) for Iranian population.

Vitamin E effects on developmental disorders in fetuses and cognitive dysfunction in adults following acrylamide treatment during pregnancy

We investigated the effects of acrylamide (AA) and vitamin E treatment during pregnancy on brain tissues of fetuses and on adult rats. Pregnant rats were divided into five groups: control, corn oil, vitamin E, AA, vitamin E +AA. The rats administered AA received10 mg/kg/day and those administered vitamin E received 100 mg/kg/day both by via oral gavage for 20 days. On day 20 of pregnancy, half of the pregnant rats were removed by cesarean section in each group. Morphological development parameters were measured in each fetus and histopathological, biochemical and genetic analyses were conducted on the fetuses. The remaining pregnant rats in each group gave birth to the fetuses vaginally and biochemical, histopathological, genetic and cognitive function tests were conducted when the pups were 8 weeks old. AA administration caused adverse effects on fetus number, fetal weight, crown-rump length, placenta and brain weight. AA negatively affected malondialdehyde, reduced glutathione, total oxidant and antioxidant status, brain derived neurotrophic factor (BDNF) levels, brain tissue morphology, histopathology error score and gene expression (BDNF/β-actin mRNA ratio) in fetuses. AA administration caused disruption of biochemical, histopathological and cognitive functions in adult rats. Vitamin E provided protection against neurotoxicity in both fetuses and adult rats. We conclude that exposure to AA during pregnancy should be avoided and adequate amounts of antioxidants, such as vitamin E, should be consumed.

Effect of Microwave Heating on the Acrylamide Formation in Foods

Acrylamide (AA) is a neurotoxic and carcinogenic substance that has recently been discovered in food. One of the factors affecting its formation is the heat treatment method. This review discusses the microwave heating as one of the methods of thermal food processing and the influence of microwave radiation on the acrylamide formation in food. In addition, conventional and microwave heating were compared, especially the way they affect the AA formation in food. Available studies demonstrate differences in the mechanisms of microwave and conventional heating. These differences may be beneficial or detrimental depending on different processes. The published studies showed that microwave heating at a high power level can cause greater AA formation in products than conventional food heat treatment. The higher content of acrylamide in microwave-heated foods may be due to differences in its formation during microwave heating and conventional methods. At the same time, short exposure to microwaves (during blanching and thawing) at low power may even limit the formation of acrylamide during the final heat treatment. Considering the possible harmful effects of microwave heating on food quality (e.g., intensive formation of acrylamide), further research in this direction should be carried out.

Healthy eating recommendations: good for reducing dietary contribution to the body's advanced glycation/lipoxidation end products pool?

The present review aims to give dietary recommendations to reduce the occurrence of the Maillard reaction in foods and in vivo to reduce the body's advanced glycation/lipoxidation end products (AGE/ALE) pool. A healthy diet, food reformulation and good culinary practices may be feasible for achieving the goal. A varied diet rich in fresh vegetables and fruits, non-added sugar beverages containing inhibitors of the Maillard reaction, and foods prepared by steaming and poaching as culinary techniques is recommended. Intake of supplements and novel foods with low sugars, low fats, enriched in bioactive compounds from food and waste able to modulate carbohydrate metabolism and reduce body's AGE/ALE pool is also recommended. In conclusion, the recommendations made for healthy eating by the Spanish Society of Community Nutrition (SENC) and Harvard University seem to be adequate to reduce dietary AGE/ALE, the body's AGE/ALE pool and to achieve sustainable nutrition and health.

An efficient reduction of unsaturated bonds and halogen-containing groups by nascent hydrogen over Raney Ni catalyst

Presence of unsaturated bonds and halogen-containing groups is the most common characteristic of toxic and harmful environmental pollutants. Herein, catalytic hydrogenation was chosen as a water quality control method for such contaminants. Considering the safety, availability and activity of the hydrogen source, electrochemical in situ hydrogen generation was introduced. Under the combined action of Raney Ni (R-Ni) and nascent hydrogen (Nas-H₂), three compounds (50 mg L^-1, 90 ml), i.e., acrylamide, 2, 6-dibromo-4-nitrophenol and 2-chloro-4-fluorobenzonitrile achieved complete hydrogenation reduction in a short time. The improved system realized the quantitative consumption of hydrogen source and the efficient operation of hydrogenation reaction under mild conditions. Additionally, the alkaline environment formed by hydrogen evolution reaction (HER) avoided secondary pollution caused by catalyst dissolution. Atomic hydrogen (H·) produced from R-Ni and Nas-H₂ was the active free radical of the reaction. The hydrogenation activities of different functional groups were obtained according to the following order: Ph-NO₂ ＞ -C = C- ＞ Ph-C≡N ＞ Ph-Br ＞ Ph-Cl ＞ Ph-F. This work indicates that the catalytic hydrogenation system consisting of R-Ni and Nas-H₂ is a promising technology to reduce unsaturated bonds and halogen-containing groups.

Silymarin Ameliorates Acrylamide-Induced Hyperlipidemic Cardiomyopathy in Male Rats

Acrylamide (AA) is a well-known potent carcinogen and neurotoxin that has been recently linked to atherosclerotic pathogenesis. The present study is aimed at investigating the protective effect of silymarin (SIL) as an antioxidant against AA-induced hyperlipidemic cardiomyopathy in male rats. The obtained results showed that animals exposed to AA exhibited a significant increase in the levels of cardiac serum markers, serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very-low-density lipoprotein cholesterol with a significant decrease in high-density lipoprotein cholesterol. Furthermore, AA intoxication significantly increased the malondialdehyde level (a hallmark of lipid peroxidation) and reduced antioxidant enzyme activities (i.e., superoxide dismutase, catalase, and glutathione peroxidase). SIL administration significantly attenuated all these biochemical perturbations in AA-treated rats, except for the decreased high-density lipoprotein cholesterol. Our results were confirmed by histopathological assessment of the myocardium. In conclusion, this study demonstrated a beneficial effect of SIL therapy in the prevention of AA-induced cardiotoxicity by reversing the redox stress and dyslipidemia in experimental animals.

Acrylamide in daily food in the metropolitan area of Hanoi, Vietnam

Acrylamide, a colourless and odourless crystalline solid, formed via the Maillard reaction in food, has been reported with harmful properties for humans, such as toxicity and carcinogenicity. Three hundred and four processed food samples from 17 product types, collected in Hanoi, Vietnam, were analyzed by LC-MS/MS to measure the acrylamide concentration. The limit of detection (LOD) and the limit of quantification (LOQ) of acrylamide were 1 µg Kg^-1 and 3 µg Kg^-1, respectively. Effectively, the highest acrylamide content is usually found in processed food, which is one of the primary reasons of increased acrylamide content in food. All French fried samples contained acrylamide above 500 µg kg^-1. Acrylamide concentration in non-fried noodle, vermicelli, rice noodle, phở, dried vegetable, and rice cracker is lower than in potato chips, fried potatoes, fried cake, and fried noodles. The results could be helpful to estimate exposure and risk assessment of acrylamide in Vietnam.

Reduction of acrylamide in whole-wheat bread by combining lactobacilli and yeast fermentation

This study mainly focuses on a strategy for reducing acrylamide content in whole-wheat bread by combining lactobacilli and yeast in sourdough breadmaking. Combinations of sourdough (fermented dough using different Lactobacillus strains including Lactobacillus plantarum PTCC 1896 [probiotic], L. sakei DSM 20,017, L. rhamnosus DSM 20,021, and L. delbrueckii DSM 20,081) and yeast, in comparison with yeast alone, were used for breadmaking. The results showed that acrylamide levels in breads fermented using sourdough+yeast were in all cases much lower (6.9-20 μg/kg on a dry weight basis [d.b.]) than those in the yeast-only fermented bread (47.6 μg/kg d.b.). Significant (p < 0.05) correlations were also found between pH, total titratable acids (TTA) and lactic acid, and acrylamide content. Furthermore, the obtained results showed that the moisture content of dough directly influenced the formation of acrylamide in bread (r = 0.925, p < 0.0001). In addition, no significant correlations were observed between acrylamide content in breads and either the reducing sugar or free amino acid contents in dough samples. According to the different effects of Lactobacillus strains, it could be concluded that the acrylamide reducing potential of lactobacilli was strain-specific, with L. rhamnosus being the most effective. This suggests that sourdough fermentation with appropriate Lactobacillus strains can be used as an advantageous technology to reduce the acrylamide content of whole-wheat breads.

Effect of (-)-epigallocatechin gallate (EGCG) extracted from green tea in reducing the formation of acrylamide during the bread baking process

This is the first study to investigate the extent of reduction in acrylamide formation during baking with the addition of (-)-epigallocatechin gallate (EGCG) extracted from green tea, and to determine whether EGCG influences the texture and colour attributes of bread, or interacts with other ingredients. EGCG powders were added to white bread formulations at the concentrations of 3.3, 6.6 and 9.9g·kg^-1. The amount of acrylamide in the bread was analysed using liquid chromatography-mass spectrometry. EGCG addition significantly reduced the acrylamide formation by 37% compared to the control and decreased the moisture content of the bread by 6%. It did not affect its texture attribute, but increased the lightness and the yellowness and decreased the redness of bread crust (with contrasting results in crumb). It also decreased granule size and porosity. In conclusion, EGCG fortification is a feasible method to decrease acrylamide formation in baked bread.

The Influence of pH and Sodium Hydroxide Exposure Time on Glucosamine and Acrylamide Levels in California-Style Black Ripe Olives

Acrylic acid, N-acetyl-glucosamine and glucosamine were investigated for their role in the formation of acrylamide in California-style black ripe olives [CBROs]. Levels of acrylic acid and glucosamine are reported for the first time in fresh (333.50 ± 21.88 and 243.59 ± 10.06 nmol/g, respectively) and in brine-stored olives (184.50 ± 6.02 and 165.88 ± 11.51 nmol/g, respectively). Acrylamide levels significantly increased when acrylic acid (35.2%), N-acetyl-glucosamine (29.9%), and glucosamine (124.0%) were added to olives prior to sterilization. However, isotope studies indicate these compounds do not contribute carbon and/or nitrogen atoms to acrylamide. The base-catalyzed degradation of glucosamine is demonstrated in olive pulp and a strong correlation (r² = 0.9513) between glucosamine in olives before sterilization and acrylamide formed in processed CBROs is observed. Treatment with sodium hydroxide (pH > 12) significantly reduces acrylamide levels over 1 to 5 d without impacting olive fruit texture.

Toxic effect of acrylamide on the development of hippocampal neurons of weaning rats

Although numerous studies have examined the neurotoxicity of acrylamide in adult animals, the effects on neuronal development in the embryonic and lactational periods are largely unknown. Thus, we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy. Sprague-Dawley rats were mated with male rats at a 1:1 ratio. Rats were administered 0, 5, 10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21. The gait scores were examined in pregnant rats in each group to analyze maternal toxicity. Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies. Nissl staining was used to observe histological change in the hippocampus. Immunohistochemistry was conducted to observe the condition of neurites, including dendrites and axons. Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein, growth associated protein 43, and the presynaptic vesicle membrane specific protein, synaptophysin. The gait scores of gravid rats significantly increased, suggesting that acrylamide induced maternal motor dysfunction. The number of neurons, as well as expression of growth associated protein 43 and synaptophysin, was reduced with increasing acrylamide dose in postnatal day 21 weaning rats. These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.

Investigation of the effects of acrylamide applied during pregnancy on fetal brain development in rats and protective role of the vitamin E

A liberal amount of acrylamide (AA) is produced as a result of frying or baking foods in high temperatures, and individuals take certain amounts of AA everyday by consuming these food items. Pregnant women are also exposed to AA originating from food during pregnancy and their fetus are probably affected. The rats were divided into five different groups: control (C), corn oil (CO), vitamin E (Vit E), AA, and Vit E + AA, with eight pregnant rats in each group. On the 20th day of pregnancy, fetuses were removed and brain tissues of fetuses were examined for biochemical and histological changes. AA caused degeneration in neuron structures in fetal brain tissue and caused hemorrhagic damages; dramatically decreased brain-derived neurotrophic factor levels; increased malondialdehyde, total oxidant capacity levels; and decreased reduced glutathione and total antioxidant capacity levels (p < 0.05). On the other hand, it was determined that the Vit E, a neuroprotectant and a powerful antioxidant, suppressed the effects of AA on fetal development and fetal brain tissue damage for the above-mentioned parameters (p < 0.05). It is recommended to consume food containing Vit E as a protection to minimize the toxic effects of food-oriented AA on fetus development due to the widespread nature of fast-food culture in today's life and the impossibility of protection from AA toxicity.

Effect of garlic powder on acrylamide formation in a low-moisture model system and bread baking

BACKGROUND

Acrylamide (AA) is of concern worldwide because of its neurotoxicity, genotoxicity and reproductive/developmental toxicity. Consequently, methods for minimizing AA formation during food processing are vital.

RESULTS

In this study, the formation and elimination of AA in an asparagine/glucose low-moisture model system were investigated by response surface methodology. The effect of garlic powder on the kinetics of AA formation/elimination was also evaluated. The AA content reached a maximum level (674.0 nmol) with 1.2 mmol of glucose and 1.2 mmol of asparagine after heating at 200 °C for 6 min. The AA content was greatly reduced with the addition of garlic powder. Compared to without garlic powder, an AA reduction rate of 43% was obtained with addition of garlic powder at a mass fraction of 0.05 g. Garlic powder inhibited AA formation during the generation-predominant kinetic stage and had no effect on the degradation-predominant kinetic stage. The effect of garlic powder on AA formation in bread and bread quality was also investigated. Adding a garlic powder mass fraction of 15 g to 500 g of dough significantly (P < 0.05) reduced the formation of AA (reduction rate of 46%) and had no obvious effect on the sensory qualities of the bread.

CONCLUSION

This study provides a possible method for reducing the AA content in bread and other heat-treated starch-rich foods.

The acrylamide content of smokeless tobacco products

BACKGROUND

There is considerable interest from a regulatory and public health perspective in harmful and potentially harmful constituents in tobacco products, including smokeless tobacco products (STPs). A wide range of commercial STPs from the US and Sweden, representing 80-90 % of the 2010 market share for all the major STP categories in these two countries, were analysed for the IARC Group 2A carcinogen acrylamide. These STPs comprised the following styles: Swedish loose and portion snus, US snus, chewing tobacco, moist snuff, dry snuff, soft pellet, hard pellet and plug.

RESULTS

Acrylamide was detected in all the products tested and quantified in all but one product. Concentrations ranged from 62 to 666 ng/g wet weight basis (WWB). The average levels of acrylamide (WWB) by type of STP were not significantly different (p > 0.05) except for US snus which had, on average, greater levels but with a very wide range of individual levels according to the manufacturer. Acrylamide levels in STPs were significantly and positively correlated with pH, but not with levels of either reducing sugars or ammonia nitrogen. Levels of acrylamide increased by sixfold or more (on a dry weight basis) during manufacture of a snus sample and then decreased during subsequent storage for up to 22 weeks. Acrylamide generation in tobacco generally appears to occur at lower temperatures, but longer time scales than found with food production.

CONCLUSIONS

Acrylamide is a common contaminant of STPs, formed through heat treatment of tobacco. Our data show that exposure to acrylamide from consumption of STPs is small compared with exposure from food consumption or cigarette smoking.

Potassium in agriculture--status and perspectives

In this review we summarize factors determining the plant availability of soil potassium (K), the role of K in crop yield formation and product quality, and the dependence of crop stress resistance on K nutrition. Average soil reserves of K are generally large, but most of it is not plant-available. Therefore, crops need to be supplied with soluble K fertilizers, the demand of which is expected to increase significantly, particularly in developing regions of the world. Recent investigations have shown that organic exudates of some bacteria and plant roots play a key role in releasing otherwise unavailable K from K-bearing minerals. Thus, breeding for genotypes that have improved mechanisms to gain access to this fixed K will contribute toward more sustainable agriculture, particularly in cropping systems that do not have access to fertilizer K. In K-deficient crops, the supply of sink organs with photosynthates is impaired, and sugars accumulate in source leaves. This not only affects yield formation, but also quality parameters, for example in wheat, potato and grape. As K has beneficial effects on human health, its concentration in the harvest product is a quality parameter in itself. Owing to its fundamental roles in turgor generation, primary metabolism, and long-distance transport, K plays a prominent role in crop resistance to drought, salinity, high light, or cold as well as resistance to pests and pathogens. Despite the abundance of vital roles of K in crop production, an improvement of K uptake and use efficiency has not been a major focus of conventional or transgenic breeding in the past. In addition, current soil analysis methods for K are insufficient for some common soils, posing the risk of imbalanced fertilization. A stronger prioritization of these areas of research is needed to counter declines in soil fertility and to improve food security.

Current issues in dietary acrylamide: formation, mitigation and risk assessment

Acrylamide (AA) is known as a neurotoxin in humans and it is classified as a probable human carcinogen by the International Agency of Research on Cancer. AA is produced as by-product of the Maillard reaction in starchy foods processed at high temperatures (>120 °C). This review includes the investigation of AA precursors, mechanisms of AA formation and AA mitigation technologies in potato, cereal and coffee products. Additionally, most relevant issues of AA risk assessment are discussed. New technologies tested from laboratory to industrial scale face, as a major challenge, the reduction of AA content of browned food, while still maintaining its attractive organoleptic properties. Reducing sugars such as glucose and fructose are the major contributors to AA in potato-based products. On the other hand, the limiting substrate of AA formation in cereals and coffee is the free amino acid asparagine. For some products the addition of glycine or asparaginase reduces AA formation during baking. Since, for potatoes, the limiting substrate is reducing sugars, increases in sugar content in potatoes during storage then introduce some difficulties and potentially quite large variations in the AA content of the final product. Sugars in potatoes may be reduced by blanching. Levels of AA in different foods show large variations and no general upper limit is easily applicable, since some formation will always occur. Current policy is that practical measures should be taken voluntarily to reduce AA formation in vulnerable foods since AA is considered a health risk at the concentrations found in foods.

The influence of deep frying using various vegetable oils on acrylamide formation in sweet potato (Ipomoea batatas L. Lam) chips

The objective of this study was to evaluate the precursors of acrylamide formation in sweet potato (SP) (Ipomoea batatas L. Lam) chips and to determine the effect of different types of vegetable oils (VOs), that is, palm olein, coconut oil, canola oil, and soya bean oil, on acrylamide formation. The reducing sugars and amino acids in the SP slices were analyzed, and the acrylamide concentrations of SP chips were measured. SP chips that were fried in a lower degree of unsaturation oils contained a lower acrylamide concentration (1443 μg/kg), whereas those fried with higher degree of unsaturated oils contained a higher acrylamide concentration (2019 μg/kg). SP roots were found to contain acrylamide precursors, that is, 4.17 mg/g glucose and 5.05 mg/g fructose, and 1.63 mg/g free asparagine. The type of VO and condition used for frying, significantly influenced acrylamide formation. This study clearly indicates that the contribution of lipids in the formation of acrylamide should not be neglected.

Industrially applicable strategies for mitigating acrylamide, furan, and 5-hydroxymethylfurfural in food

Acrylamide and furanic compounds, such as furan and 5-hydroxymethylfurfural (HMF), are formed in a variety of heat-treated commercial foods. They are known to be toxic and, according to the International Agency for Research on Cancer, "possibly carcinogenic to humans". As this gave rise to concern, research was carried out to study their metabolism and toxicity and elucidate the mechanistic pathways of formation. So far, many papers have been published on acrylamide, furan, and HMF occurrence, precursors and mechanisms of formation, toxicity, and detection methods, as well as on possible routes to reduce their levels in food and, thus, consumer intake. This paper reviews the interventions suggested in the literature to mitigate the presence of acrylamide and furanic compounds in food. In particular, some technological measures potentially exploitable at the industrial level are discussed extensively. These are (i) preventive strategies based on the use of asparaginase and thermal input reduction (i.e., low temperature-long time dehydration; dielectric heating) and (ii) removal intervention by means of vacuum treatment, aimed to remove the already formed acrylamide and furanic compounds from the finished product.

Effect of lactic acid fermentation of lupine wholemeal on acrylamide content and quality characteristics of wheat-lupine bread

The effect of supplementing wheat flour at a level of 15% with lupine (Lupinus angustifolius L.) wholemeal fermented by different lactic acid bacteria on acrylamide content in bread crumb as well as on bread texture and sensory characteristics was analysed. The use of fermented lupine resulted in a lower specific volume and crumb porosity of bread on an average by 14.1% and 10.5%, respectively, while untreated lupine lowered the latter parameters at a higher level (30.8% and 20.7%, respectively). The addition of lupine resulted in a higher by 43.3% acrylamide content compared to wheat bread (19.4 µg/kg dry weight (d.w.)). Results showed that acrylamide was significantly reduced using proteolytic Lactobacillus sakei and Pediococcus pentosaceus 10 strains for lupine fermentation. Although the bread supplemented with lupine spontaneous sourdough had the lowest level of acrylamide (15.6 µg/kg d.w.), it had the malodorous flavour and was unacceptable to the consumers. The lactofermentation could increase the potential use of lupine as a food ingredient while reducing acrylamide formation and enriching bread with high quality proteins.