Reduction of acrylamide formation by vanadium salt in potato French fries and chips

Dual functional roles of nutritional additives in nutritional fortification and safety of thermally processed food: Potential, limitations, and perspectives

The Maillard reaction (MR) has been established to be a paramount contributor to the characteristic sensory property of thermally processed food products. Meanwhile, MR also gives rise to myriads of harmful byproducts (HMPs) (e.g., advanced glycation end products (AGEs) and acrylamide). Nutritional additives have attracted increasing attention in recent years owing to their potential to simultaneously improve nutritional quality and attenuate HMP formation. In this manuscript, a brief overview of various nutritional additives (vitamins, minerals, fatty acids, amino acids, dietary fibers, and miscellaneous micronutrients) in heat-processed food is provided, followed by a summary of the formation mechanisms of AGEs and acrylamide highlighting the potential crosstalk between them. The main body of the manuscript is on the capability of nutritional additives to modulate AGE and acrylamide formation besides their traditional roles as nutritional enhancers. Finally, limitations/concerns associated with their use to attenuate dietary exposure to HMPs and future perspectives are discussed. Literature data support that through careful control of the addition levels, certain nutritional additives possess promising potential for simultaneous improvement of nutritional value and reduction of AGE and acrylamide content via multiple action mechanisms. Nonetheless, there are some major concerns that may limit their wide applications for achieving such dual functions, including influence on sensory properties of food products, potential overestimation of nutrition enhancement, and introduction of hazardous alternative reaction products or derivatives. These could be overcome through comprehensive assay of dose-response relationships and systematic evaluation of the diverse combinations from the same and/or different categories of nutritional additives to establish synergistic mixtures.

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.

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.

Vacuum impregnation pre-treatment: A novel method for incorporating mono- and divalent cations into potato strips to reduce the acrylamide formation in French fries

The effect of different vacuum impregnation (VI) pre-treatments of potato strips [in water (control), NaCl, KCl or CaCl2 (0.1 M) for 10 and 15 min] on acrylamide formation in French fries after deep frying in sunflower oil at 175°C for 5 min was determined. The acrylamide content of fries prepared with potato strips pre-treated by VI in distilled water decreased from 0.82 to 0.24 µg/g when time increased to 15 min. Moreover, the acrylamide content of fries from 10 min-KCl pre-treatment (0.35 µg/g) decreased significantly to 0.04 µg/g when time was 15 min (p < 0.05). In comparison to control (10 min), the VI pre-treatment in KCl and NaCl for 15 min reduced the relative content of acrylamide by 95 and 91%, respectively, and VI in distilled water was able to decrease this value by 71%. Results indicated that monovalent cations (K and Na) were more effective in reducing acrylamide formation than divalent cation (Ca2+) when the VI pre-treatment time increased to 15 min. In conclusion, VI as a pre-treatment for mono- and divalent cations in fried potato production could be a useful technique in industrial applications to reduce acrylamide formation in fries in a short time.

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.

Influence of Water, NaCl and Citric Acid Soaking Pre-Treatments on Acrylamide Content in French Fries Prepared in Domestic Conditions

The aim of this study was to investigate the influence of some pre-treatment applications toward acrylamide mitigation in potatoes fried in domestic conditions modeled after those found in Romania, by using a pan and a fryer. Before being fried in a pan, potato strips were treated in one of the following ways: soaked in cold water for 15, 60, and 120 min (a); soaked in hot water at different combinations of temperatures and durations (60, 70, 80 °C for 5, 10, 15 min) (b); soaked in a NaCl solution (c), and; in a citric acid solution (d) both solutions of 0.05% and 1% concentration for 30 min. For potatoes fried in a fryer, the (a) pre-treatment and soaking in water at 80 °C for 5, 10, and 15 min were applied. Untreated samples were used as a control. French fries were analyzed in terms of moisture and acrylamide content, color, and texture parameters. The pre-treatments applied reduced the acrylamide content in French fries by 4-97% when fried in the pan and by 25-47% when fried in the fryer. Acrylamide content of French fries was negatively correlated with L* parameter and moisture content and positively correlated with a* parameter. The pre-treatments applied can be used successfully by consumers to reduce acrylamide content.

Influence of coating material and processing parameters on acrylamide formation in potato patties

Influence of moisture content (MC, 65–35%), frying temperature/time (150–200 °C, 4–12 min), and coating materials (patties coated with bread crumbs – PBC and patties coated with wheat semolina – PSC) on acrylamide formation in potato patties was investigated. Acrylamide content increased with decrease in MC and increase in temperature/time, except for PBC at higher temperatures (180 °C, 8 & 12 min and 200 °C). Morphology analysis suggested PBC to possess more porous coating that resulted in higher oil penetration leading to higher heat transfer rate, moisture evaporation and drying at higher frying temperatures. This led to an initial acceleration of acrylamide formation in PBCs at higher temperatures, followed by its degradation resulting in low acrylamide content in final product. Based on sensory analysis and lowest acrylamide formation, the optimal conditions for frying of potato patties were: (i) MC: 66.53 ± 2.2% (ii) frying temperature: 165 °C (iii) frying time: 4 min.

Effect of nixtamalization processes on mitigation of acrylamide formation in tortilla chips

Acrylamide can be generated from food components during tortilla chips frying. Thus, the aim of this research was to study different nixtamalization processes as traditional (TNP) with lime [Ca(OH)₂], ecological (ENP) with CaCO₃, classic nixtamalization (CNP) that uses wood ash and extrusion (EXT) with no Ca⁺² source on mitigating the acrylamide formation in deep-fat frying tortilla chips. Acrylamide quantification was done through HPLC-UV. Lower acrylamide content in tortilla chips was for CNP with 46.3 µg/kg, followed by TNP with 55.0 µg/kg, ENP with 694.6 µg/kg and EXP with 1443.4 µg/kg. Differences in acrylamide values among samples can be related to effect of cations (Ca²⁺, Mg²⁺, Fe²⁺, Zn²⁺, Na⁺ and K⁺) present in wood ashes, lime and salts used as raw materials. Correlation of (r = 0.85; p <0.0005) was observed in color of tortilla chips, moisture, texture, blisters, and oil with acrylamide. Nixtamalization process is an effective and inexpensive strategy for acrylamide mitigation.

Application of pretreatment methods on agricultural products prior to frying: a review

Frying is one of the methods of processing foods, which imparts flavour, taste, colour and crispness in the fried foods. In spite of an increase in the demand for fried foods by consumers all over the world, the danger posed by consuming too much fat is still a challenge. Many researchers have put forward many ideas on how to reduce the oil uptake and improve the nutritional and organoleptic qualities of foods during frying. Several pretreatment techniques applied to food materials prior to frying have been investigated by researchers in a bid to reduce the oil uptake and improve the quality parameters of fried foods. Therefore, this review focuses on the various pretreatment methods and the recent novel methods like ultrasound, infrared, superheated steam drying, microwave technique and pulsed electric field applied to foods prior to frying and its effects on the qualities of fried foods. © 2017 Society of Chemical Industry.

Nutrient Composition of Continuous and Kettle Cooked Potato Chips from Three Potato Cultivars

Potatoes are a good source of various nutritional and health promoting compounds such as Vitamin C, dietary fibers, potassium, magnesium, and carbohydrates. One of its fried products “potato chips” is the most popular snacks among consumers of all ages. This study presents useful data on total fats, reducing sugars, Vitamin C, minerals, total phenolics, antioxidant activity, glycoalkaloids, and acrylamide levels of potato chips made from three potato cultivars (Snowden, Lamoka, and Atlantic) grown at different locations in the USA. From the results obtained, these potato chips are notable for their high content of vitamin C (min, 6.54 - max, 29.79 mg/100g), K (min, 1.10 - max, 1.65 %), and dietary fibers (2.14 to 3.71 %). The average levels of acrylamide were 902.02 µg/kg with a range 866.96 - 948.7 in continuous frying chips and 873.369 µg/kg in kettle cooked chips with the range 840.06 - 932.76. Kettle cooked potato chips retained a higher amount of nutrients and lower level of fats.

Simultaneous inhibition of acrylamide and hydroxymethylfurfural formation by sodium glutamate microcapsules in an asparagine-glucose model system

Inhibiting the formation of acrylamide (AA) and hydroxymethylfurfural (HMF) during food heating processes has attracted considerable investigative efforts due to potential health concerns associated with these compounds. The main purpose of this work is to demonstrate a strategy to simultaneously inhibit the formation of AA and HMF with sodium glutamate microcapsules selected to confirm the efficacy of this strategy. An asparagine-glucose aqueous model system was prepared containing free sodium glutamate and sodium glutamate microcapsules. Compared to adding free sodium glutamate, the maximum inhibition efficiency for AA and HMF was found to increase by addition of sodium glutamate microcapsules to 19.07 and 84.32%, respectively. Moreover, the kinetics of AA and HMF formation were studied in this model system. The AA inhibition efficiency significantly increased from 6.75 to 60.35% and the HMF inhibition efficiency significantly increased from 5.98 to 79.72% with increasing the reaction time from 25 to 40 min, indicating that the sodium glutamate microcapsules strategy proves to be far superior at prolonged heating times. These findings suggested that this inhibition strategy may provide promising characteristics for a variety of applications in food processing.

Evaluation of acrylamide-removing properties of two Lactobacillus strains under simulated gastrointestinal conditions using a dynamic system

The aim of this study was to evaluate the capability of Lactobacillus reuteri NRRL 14171 and Lactobacillus casei Shirota to remove dietary acrylamide (AA) under simulated gastrointestinal conditions using a dynamic system. The effects of different AA levels or bacteria concentration on toxin removal by Lactobacillus strains were assessed. Thereafter, AA-removing capability of bacteria strains under either fasting or postprandial simulated gastrointestinal conditions was evaluated. Commercial potato chips were analyzed for their AA content, and then used as a food model. Average AA content (34,162μg/kg) in potato chips exceeded by ca. 34-fold the indicative values recommended by the EU. Toxin removal ability was dependent on AA content and bacterial cell concentration. A reduction on bacterial viability was observed in the food model and at the end of both digestive processes evaluated. However, bacteria survived in enough concentrations to remove part of the toxin (32-73%). Both bacterial strains were able to remove AA under different simulated gastrointestinal conditions, being L. casei Shirota the most effective (ca. 70% removal). These findings confirmed the risk of potato chips as dietary AA exposure for consumers, and that strains of the genus Lactobacillus could be employed to reduce the bioavailability of dietary AA.

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

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

Processing treatments for mitigating acrylamide formation in sweetpotato French fries

Acrylamide formation in sweetpotato French fries (SPFF) is likely a potential health concern as there is an increasing demand for good-quality fries from carotene-rich sweetpotatoes (SP). This is the first report on acrylamide formation in SPFF as affected by processing methods. Acrylamide levels in SPFF from untreated SP strips fried at 165 °C for 2, 3, and 5 min were 124.9, 255.5, and 452.0 ng/g fresh weight, which were reduced by about 7 times to 16.3, 36.9, and 58.3 ng/g, respectively, when the strips were subjected to processing that included water blanching and soaking in 0.5% sodium acid pyrophosphate before frying. An additional step of strip soaking in 0.4% calcium chloride solution before par-frying increased the calcium content from 0.2 to 0.8 mg/g and decreased the acrylamide levels to 6.3, 17.6, and 35.4 ng/g, respectively. SPFF with acrylamide level of <100 ng/g or several times lower than that of white potato French fries can be obtained by integrating processing treatments commonly used in the food industry.