Modelling the effect of asparaginase in reducing acrylamide formation in biscuits

Strategies to reduce neurotoxic acrylamide in biscuits, a systematic review

In this systematic review, considering the wide consumption of biscuits, the research that has been designed so far to reduce acrylamide in biscuits is discussed. Some methods were the use of antioxidants, some food additives, optimization of baking methods, suppression of acrolein production, and suppression of Maillard reaction. The advantages and disadvantages of each of these methods are discussed in this systematic review. The most important possible mechanism in the formation of acrylamide is the Maillard reaction.The greatest influence of the intervention effects was seen in the studies in which the Maillard reaction was suppressed. In some studies, this efficiency was observed above 90 %. It has also been observed in some studies that acrylamide is significantly reduced by using some antioxidants in the biscuit formulation. In this condition, a decrease in the amount of acrylamide was observed in the range of 50-90 % depending on the type of antioxidant. In this regard, the greatest reduction effect was reported with the use of tropical fruits and bamboo leaves in the formulation of biscuits.

Influence of Asparaginase on Acrylamide Content, Color, and Texture in Oat, Corn, and Rice Cookies

The safety of cereal-based baked goods can be compromised by acrylamide, a processing contaminant and class 2A carcinogen. One method to prevent acrylamide formation is by converting asparagine to aspartic acid using asparaginases. Four different asparaginases were tested using two dough incubation temperatures and dosages for oat, corn, and rice cookies. To evaluate the impact of asparaginases on product quality, color and texture were measured. Acrylamide was reduced by up to 97, 95, and 92% for oat, corn, and rice cookies, respectively, compared to the control. Asparaginase treatment resulted in minor changes in color and texture. There was a strong correlation between acrylamide concentrations in cookies and the free asparagine content of the flour. By minimizing the formation of acrylamide while maintaining product quality, the use of asparaginases offers a promising approach to enhancing food safety standards and protecting public health, potentially influencing regulatory guidelines and consumer preferences.

Effect of Oat Fiber Preparations with Different Contents of β-Glucan on the Formation of Acrylamide in Dietary Bread (Rusks)

In the literature, there are few reports indicating hydrocolloids as a factor capable of reducing the amount of acrylamide formed in food. Therefore, the aim of the study was to examine the ability of soluble oat fiber to reduce the amount of acrylamide formed in the process of obtaining rusks. The effect of the concentration of β-glucans in oat fiber preparations at 20% and 30% and the amount of preparations used at 10%, 15%, and 20% was investigated. On the basis of the obtained test results, it was shown that the most optimal concentration of oat fiber preparation in rusks recipe is at 15%, regardless of the content of β-glucan in it. This concentration makes it possible to reduce the amount of acrylamide formed in baked goods and rusks by ~70% and ~60%, respectively, while maintaining the desired physical and chemical properties of the product. In addition, it was shown that the browning index and water activity strongly correlate with the content of acrylamide in rusks, which makes them good markers of this compound in rusks. The use of hydrocolloids in the form of oat fiber preparations with different contents of β-glucan as a tool for reducing the amount of acrylamide in rusks, at the same time, offers the possibility of enriching these products with a soluble dietary fiber with health properties.

Thermal Stability Enhancement of L-Asparaginase from Corynebacterium glutamicum Based on a Semi-Rational Design and Its Effect on Acrylamide Mitigation Capacity in Biscuits

Acrylamide is present in thermally processed foods, and it possesses toxic and carcinogenic properties. L-asparaginases could effectively regulate the formation of acrylamide at the source. However, current L-asparaginases have drawbacks such as poor thermal stability, low catalytic activity, and poor substrate specificity, thereby restricting their utility in the food industry. To address this issue, this study employed consensus design to predict the crucial residues influencing the thermal stability of Corynebacterium glutamicum L-asparaginase (CgASNase). Subsequently, a combination of site-point saturating mutation and combinatorial mutation techniques was applied to generate the double-mutant enzyme L42T/S213N. Remarkably, L42T/S213N displayed significantly enhanced thermal stability without a substantial impact on its enzymatic activity. Notably, its half-life at 40 °C reached an impressive 13.29 ± 0.91 min, surpassing that of CgASNase (3.24 ± 0.23 min). Moreover, the enhanced thermal stability of L42T/S213N can be attributed to an increased positive surface charge and a more symmetrical positive potential, as revealed by three-dimensional structural simulations and structure comparison analyses. To assess the impact of L42T/S213N on acrylamide removal in biscuits, the optimal treatment conditions for acrylamide removal were determined through a combination of one-way and orthogonal tests, with an enzyme dosage of 300 IU/kg flour, an enzyme reaction temperature of 40 °C, and an enzyme reaction time of 30 min. Under these conditions, compared to the control (464.74 ± 6.68 µg/kg), the acrylamide reduction in double-mutant-enzyme-treated biscuits was 85.31%, while the reduction in wild-type-treated biscuits was 68.78%. These results suggest that L42T/S213N is a promising candidate for industrial applications of L-asparaginase.

Effective mitigation in the amount of acrylamide through enzymatic approaches

Acrylamide (AA), as a food-borne toxicant, is created at some stages of thermal processing in the starchy food through Maillard reaction, fatty food via acrolein route, and proteinous food using free amino acids pathway. Maillard reaction obviously takes place in thermal-based products, being responsible for specific sensory attributes; AA formation, thereby, is unavoidable during the thermal processing. Additionally, AA can naturally occur in soil and water supply. In order to reduce the levels of acrylamide in cooked foods, mitigation techniques can be separated into three different types. Firstly, starting materials low in acrylamide precursors can be used to reduce the acrylamide in the final product. Secondly, process conditions may be modified in order to decrease the amount of acrylamide formation. Thirdly, post-process intervention could be used to reduce acrylamide. Conventional or emerging mitigation techniques might negatively influence the pleasant features of heated foods. The current study summarizes the effect of enzymatic reaction induced by asparaginase, glucose oxidase, acrylamidase, phytase, amylase, and protease to possibly inhibit AA formation or progressively hydrolyze formed AA. Not only enzyme-assisted AA reduction could dramatically maintain bio-active compounds, but also no damaging impact has been reported on the sensorial and rheological properties of the final heated products. The enzyme engineering can be applied to ameliorate enzyme functionality through altering the amino acid sequence like site-specific mutagenesis and directed evolution, chemical modifications by covalent conjugation of L-asparaginase onto soluble/insoluble biocompatible polymers and immobilization. Moreover, it would be possible to improve the enzyme's physical, chemical, and thermal stability, recyclability and prevent enzyme overuse by applying engineered ones. In spite of enzymes' cost-effective and eco-friendly, promoting their large-scale usages for AA reduction in food application and AA bioremediation in wastewater and soil resources.

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.

Appraisal of cytotoxicity and acrylamide mitigation potential of L-asparaginase SlpA from fish gut microbiome

L-asparaginase catalyzes the hydrolysis of L-asparagine to L-aspartic acid and ammonia. It has application in the treatment of acute lymphoblastic leukemia in children, as well as in other malignancies, in addition to its role as a food processing aid for the mitigation of acrylamide formation in the baking industry. Its use in cancer chemotherapy is limited due to problems such as its intrinsic glutaminase activity and associated side effects, leading to an increased interest in the search for novel L-asparaginases without L-glutaminase activity. This study reports the cloning and expression of an L-asparaginase contig obtained from whole metagenome shotgun sequencing of Sardinella longiceps gut microbiota. Purified recombinant glutaminase-free L-asparaginase SlpA was a 74 kDa homodimer, with maximal activity at pH 8 and 30 °C. K_m and V_max of SlpA were determined to be 3.008 mM and 0.014 mM/min, respectively. SlpA displayed cytotoxic activity against K-562 (chronic myeloid leukemia) and MCF-7 (breast cancer) cell lines with IC₅₀ values of 0.3443 and 2.692 U/mL, respectively. SlpA did not show any cytotoxic activity against normal lymphocytes and was proved to be hemocompatible. Pre-treatment of biscuit and bread dough with different concentrations of SlpA resulted in a clear, dose-dependent reduction of acrylamide formation during baking. KEY POINTS: • Cloned and expressed L-asparaginase (SlpA) from fish gut microbiota • Purified SlpA displayed good cytotoxicity against K-562 and MCF-7 cell lines • SlpA addition caused a significant reduction of acrylamide formation during baking.

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.

Covalent Immobilization of L-Asparaginase and Optimization of Its Enzyme Reactor for Reducing Acrylamide Formation in a Heated Food Model System

Acrylamide is a potent carcinogen and neurotoxin that is mainly formed by the Maillard reaction of asparagine with starch at high temperatures. In this work, a food safety immobilization system for L-asparaginase (L-ASNase) consisting of food-grade agarose (Aga) spheres and N-hydroxysuccinimide esters was developed to decrease the formation of acrylamide in a fluid food model system. L-asparaginase was successfully immobilized with a maximum immobilization efficiency of 68.43%. The immobilized enzymes exhibited superior storage stability and reusability with 93.21 and 72.25% of the initial activity retained after six consecutive cycles and storage for 28 days, indicating its high industrial application potential. Meanwhile, a simplified mathematical model of the enzyme reactor was developed and verified with experiments, which demonstrated its auxiliary role in the design and optimization of reactors. In addition, simulated fluidized food components were continuously catalyzed in the designed packed bed reactor, achieving a reduction rate of nearly 89%.

Oral Administration of Acrylamide Worsens the Inflammatory Responses in the Airways of Asthmatic Mice Through Agitation of Oxidative Stress in the Lungs

Acrylamide is a toxic chemical substance produced when starch-rich foods are fried at high temperatures. Asthma is a chronic and complicated respiratory disease, of which genetic and environmental factors are the main triggers. Orally-received components may have an effect on asthma pathophysiology. The aim of this study was to investigate the role of AA as a stimulus in asthma. BALB/c mice were allocated into four groups as follows: two OVA-sensitized asthmatic groups, including one treated with AA by gavage feeding and one non-treated (asthma group), and two healthy (non-asthmatic) groups, one treated with AA by gavage feeding and one non-treated (negative control group). Airway hyperresponsiveness, cell count, cytokine levels in BAL fluid, lung histopathology, IgE levels, and oxidative stress indices including plasma level of MDA, pulmonary antioxidant enzymes (SOD and CAT) levels, HP content, and collagen fiber accumulation in lung tissue were measured. We found that the group of mice treated with both OVA and AA (asthmatic and AA-treated mice) experienced higher levels of asthma-associated biomarkers, including higher enhanced pause (Penh value), eosinophilic inflammation, mucus hyper secretion, goblet cell hyperplasia, total and OVA-specific IgE levels, IL-4, IL-5, and IL-13 levels than the group sensitized only with OVA (asthmatic mice). The OVA-AA-treated mice also experienced worsened levels of oxidative stress indicators. Healthy (non-asthmatic) mice that only received AA were in similar conditions to healthy untreated mice (negative control group). The OVA-AA-treated group showed more severe allergic asthma symptoms in comparison to the group only sensitized with OVA. Therefore, food/water contaminated with AA can act as a stimulant of allergic asthma and exacerbate the bronchial inflammatory responses.

Evaluation of acrylamide levels in cereal products from the Romanian market during the 2017 and 2018 period

Cereal products are the most consumed in Romania being the main contributors to daily acrylamide exposure. The paper aims to present for the first time a general situation regarding the evolution of the acrylamide levels content from cereal products, on the Romanian market, during 2017-2018 periods, as a result of legislative measures imposed by the European Union (EU). For this purpose, the levels of acrylamide in 55 selected cereal products samples were evaluated. The cereal products analyzed were grouped in biscuits, confectionery, expanded cereals, bakery products and specialties. The acrylamide content from the cereal products were detected using GC-MS/MS method. The highest level of acrylamide was found in biscuits, whereas the lowest level was determined in bakery products. The most of the cereal products samples analyzed (90.9%) was below the reference levels established by the EU Regulation for the acrylamide level from 2017 EC (2013/647/EU) and 2018 EC (2017/2158/ EU). From the 55 cereal products analyzed, only 5 biscuits samples exceeded the reference levels established by the European Commission, one in 2017 and four in 2018 period.

Mitigation strategies of acrylamide, furans, heterocyclic amines and browning during the Maillard reaction in foods

The Maillard reaction (MR) occurs widely during food manufacture and storage, through controlled or uncontrolled pathways. Its consequences are ambiguous depending on the nature and processing of the food products. The MR is often used by food manufacturer to develop appealing aromas, colour or texture in food products (cereal based food, coffee, meat…). However, despite some positive aspects, the MR could decrease the nutritional value of food, generate potentially harmful compounds (e.g. acrylamide, furans, heterocyclic amines) or modify aroma or colour although it is not desired (milk, fruit juice). This paper presents a review of the different solutions available to control or moderate the MR in various food products from preventive to removal methods. A brief reminder of the role and influence of the MR on food quality and safety is also provided.

The kinetics of the inhibition of acrylamide by glycine in potato model systems

BACKGROUND

Acrylamide (AA) is a potential carcinogen which widely exists in heat-processed foods. The addition of glycine (Gly) has been shown to reduce the formation of AA. The objective of this work was to investigate the kinetics of the inhibition of AA by Gly in both asparagine (Asn)/glucose (Glc) and Asn/Glc/Gly potato model systems during heating at 160 °C, 180 °C, and 200 °C.

RESULTS

The simplified two consecutive first-order kinetic model fitted well to the changes of AA in both systems. No significant difference in rate constant (kF) and apparent activation energy (EaF) was observed for AA formation between the two systems (P > 0.05). Whereas EaE and only kE at 200 °C for AA elimination in the Asn/Glc/Gly system was significantly higher than Asn/Glc system (P < 0.05). The elimination reaction between Gly and AA was confirmed by the identification of their major reaction product 2-((3-amino-3-oxopropyl)amino)acetic acid in the Asn/Glc/(15)  N-Gly system.

CONCLUSION

The reduction of AA by Gly is predominantly attributed to the elimination reaction between Gly and AA.

Acrylamide mitigation strategies: critical appraisal of the FoodDrinkEurope toolbox

Not all the strategies proposed in FoodDrinkEurope toolbox have equal value in terms of efficacy and cost/benefit ratio.

Acrylamide analysis in food by liquid chromatographic and gas chromatographic methods

Acrylamide (AA) is a compound classified as carcinogenic to humans by the International Agency for Research on Cancer. It was first discovered to be present in certain heated processed food by the Swedish National Food Administration (SNFA) and University of Stockholm in early 2002. The major pathway for AA formation in food is the Maillard reaction between reducing sugar and the amino acid asparagine at high temperature. Since the discovery of AA's presence in food, many analytical methods have been developed for determination of AA contents in different food matrices. Also, several studies have been conducted to develop extraction procedures for AA from difficult food matrices. AA is a small, highly polar molecule, which makes its extraction and analysis challenging. Many articles and reviews have been published dealing with AA in food. The aim of the review is to discuss AA formation in food, the factors affecting AA formation and removal, AA exposure assessment, AA extraction and cleanup from food samples, and analytical methods used in AA determination, such as high-performance liquid chromatography (HPLC) and gas chromatography (GC). Special attention is given to sample extraction and cleanup procedures and analytical techniques used for AA determination.

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.

Biochemical characterization of a novel L-Asparaginase with low glutaminase activity from Rhizomucor miehei and its application in food safety and leukemia treatment

A novel fungal gene encoding the Rhizomucor miehei l-asparaginase (RmAsnase) was cloned and expressed in Escherichia coli. Its deduced amino acid sequence shared only 57% identity with the amino acid sequences of other reported l-asparaginases. The purified l-asparaginase homodimer had a molecular mass of 133.7 kDa, a high specific activity of 1,985 U/mg, and very low glutaminase activity. RmAsnase was optimally active at pH 7.0 and 45°C and was stable at this temperature for 30 min. The final level of acrylamide in biscuits and bread was decreased by about 81.6% and 94.2%, respectively, upon treatment with 10 U RmAsnase per mg flour. Moreover, this l-asparaginase was found to potentiate a lectin's induction of leukemic K562 cell apoptosis, allowing lowering of the drug dosage and shortening of the incubation time. Overall, our findings suggest that RmAsnase possesses a remarkable potential for the food industry and in chemotherapeutics for leukemia.

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.

Mitigating effect of amaranth (Amarantus hypochondriacus) protein on acrylamide formation in foods

The effect of addition of amaranth flour and amaranth protein isolate to both a glucose/asparagine model system and real foods (cookies, fried tortilla chips, and baked tortilla chips) was studied to analyse the acrylamide mitigating potential of this underexploited plant with attractive nutraceutical properties. Addition of amaranth flour, with a relatively low protein content (16.45%), did not mitigate acrylamide in either the model system or the studied foods. On the contrary, addition of amaranth protein isolate decreased acrylamide content by 35-40% in the model system, 89% in cookies, 51% in fried tortilla chips, and 62% in baked tortilla chips. This acrylamide reduction was obtained without change in the colour or the texture of the cookies. On the contrary, colour remained unchanged in tortilla chips, but the addition of amaranth protein isolate increased the hardness (16-36%) of the produced tortillas. Although a much more detailed sensory evaluation of cookies and tortilla chips prepared using amaranth protein isolate is needed, the above results suggest that the use of amaranth protein may be an interesting way to both mitigate acrylamide formation and improve nutritional properties of foods.