Acrylamide in Food (eBook)

Analysis, Content and Potential Health Effects

Vural Gokmen (Herausgeber)

eBook Download: PDF | EPUB

2015 | 1. Auflage
532 Seiten
Elsevier Science (Verlag)
978-0-12-802875-9 (ISBN)

Infos

Acrylamide in Food: Analysis, Content and Potential Health Effects provides the recent analytical methodologies for acrylamide detection, up-to-date information about its occurrence in various foods (such as bakery products, fried potato products, coffee, battered products, water, table olives etc.), and its interaction mechanisms and health effects. The book is designed for food scientists, technologists, toxicologists, and food industry workers, providing an invaluable industrial reference book that is also ideal for academic libraries that cover the domains of food production or food science. As the World Health Organization has declared that acrylamide represents a potential health risk, there has been, in recent years, an increase in material on the formation and presence of acrylamide in different foods. This book compiles and synthesizes that information in a single source, thus enabling those in one discipline to become familiar with the concepts and applications in other disciplines of food science. - Provides latest information on acrylamide in various foods (bakery products, fried potato products, coffee, battered products, water, table olives, etc.) - Explores acrylamide in the food chain in the context of harm, such as acrylamide and cancer, neuropathology of acrylamide, maternal acrylamide and effects on offspring and its toxic effects in tissues - Touches on a variety of subjects, including acrylamide, high heated foods, dietary acrylamide, acrylamide formation, N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA), acrylamide removal, L-asparaginase, and acrylamide determination - Presents recent analytical methodologies for acrylamide determination, including liquid chromatographic tandem mass spectrometry and gas chromatography-mass spectrometry

Textauszug

Introduction: Potential Safety Risks Associated with Thermal Processing of Foods

Vural Gökmen,     Department of Food Engineering, Hacettepe University, Ankara, Turkey

Risks Associated with Thermal Processing

Processing of foods is essential to improve microbiological safety, to increase nutritional quality, and to reduce the levels of potentially toxic compounds [1]. The thermal processing of foods, domestically or industrially, is an ancient practice that improves the organoleptic properties of the foods, their preservation, and microbiological safety [2].

Thermal processing is an important treatment for food preservation, especially in the manufacture of shelf-stable foods with specific nutritional properties. In addition, it is indispensable for determining the sensory properties, in particular color, texture, and flavor in fried, baked, and roasted products (Figure 1).

Heat induces chemical change and a plethora of new molecules are generated in foods, some of which have been claimed to impart positive health effects, for example, acting as health-promoting antioxidants and antimutagens [2]. On the other hand, it may lead to the formation of heat-induced toxic compounds, so-called thermal process contaminants, that exhibit carcinogenic and in some cases mutagenic properties, such as heterocyclic amines, acrylamide, furan, furfurals, and chloropropanols [3–6]. In particular, the heterocyclic aromatic amines and polycyclic aromatic hydrocarbons are classes of compounds that are formed under severe thermal conditions, and sources of the latter may also be occupational environment, tobacco smoke, and air pollution.

Thermally processed foods like bakery products, roasted coffee, snack foods, baby purees, and refined oils may contain above-mentioned compounds at varying amounts as a result of heat-induced conversions of certain compounds naturally available in food products (Figure 2). The final concentrations of thermal-process contaminants in foods depend on the concentration of their corresponding precursors as well as the severity of thermal-processing conditions.

Chemistry of the Maillard Reaction

The chemical reactions that lead to the formation of thermal-process contaminants in foods are diverse. They mainly involve lipids, carbohydrates, and proteins with or without free amino acids as precursors. The formation of reactive intermediates from especially carbohydrates and lipids may play an important role. The reaction pathways are interrelated and strongly dependent on the size and composition of foods and processing conditions [1].

Figure 1 Commonly consumed foods that are exposed to extreme temperatures during processing.

Figure 2 Examples of some naturally occurring compounds in foods leading to certain potentially harmful substances during thermal processing.

Among the reactions occurring in food during heating, the reaction between reducing carbohydrates and free amino groups of proteins or amino acids is the major source of neo-formed compounds. This reaction, so-called the Maillard reaction, causes the development of brown color in foods. The Maillard reaction gives unique color and flavor to food products. However, there are also certain undesired consequences of the Maillard reaction such as (1) the loss of nutrients like lysine, (2) generation of toxic compounds like acrylamide, and (3) formation of advanced glycation end products (AGEs) that are responsible for the development of certain age-related diseases. The Maillard reaction has three stages in which typical products are formed (Figure 3). Some of them like N-ε-fructosyllysine (FL) and carboxymethyllysine (CML) have been used to evaluate the degree of protein glycation in heated foods that indicate the loss of nutritive value [7–9]. Some other Maillard reaction products such as acrylamide and furfurals indicate the safety risks created in foods during thermal processing due to the potential adverse effects of these compounds on human health [1,10–12].

Figure 3 Typical products formed during the stages of Maillard reaction.

Acrylamide in Heated Foods

In April 2002, a report by the Swedish Authorities on the presence of acrylamide (2-propenamide) in a wide range of fried and oven-cooked foods [4] attracted worldwide attention, due to the fact that acrylamide is classified as probably carcinogenic to humans (Group 2A) by the IARC [10]. Acrylamide is formed in food as a result of cooking practices, many of which have been used by mankind for many centuries. Initial surveys have shown that relatively high concentrations of acrylamide are found in high-carbohydrate foodstuffs such as potato chips, French fries, pan-fried potato products, and crisp bread [2]. The main pathway of acrylamide formation in foods is linked to the Maillard reaction and, in particular, the amino acid asparagine [13–15].

Presence of acrylamide in common heated foods is considered as an important food safety problem by international authorities. Acrylamide exposure varies depending upon the population’s eating habits, and the way the foods are processed and prepared. Generally, fried potato products, bakery products, and roasted coffee appear as the most important food categories that contribute most to acrylamide exposure. The levels of acrylamide in heat-processed foods depend on certain recipe factors and thermal-processing conditions. The initial concentrations of precursors and processing temperatures are known to affect the rate of acrylamide formation in foods [16–20].

During baking or frying of foods, the evaporation of water, being an important barrier to internal energy increase, limits the amounts of acrylamide formed. However, greater energy input to the food at higher temperatures causes faster drying, and hence the temperature and moisture levels favor the formation of acrylamide to set in early during the process [19]. Time–temperature history differs in different locations of food as a result of simultaneous heat and mass transfer. Temperature rises much faster on the surface than the interior parts of food during heating under conventional conditions [21]. This makes the surface of foods more risky part from the viewpoint of chemical reactions leading to undesired toxic compounds. It has been reported that acrylamide formation takes place mainly at the surface and in near-surface regions, because during heating, the conditions in this part of foods become favourable [19]. This causes a large difference between the acrylamide concentrations of the surface and the core regions of food.

For optimization, it seems very useful to find a relationship between time and temperature to evaluate potential risks and benefits of the thermal process. Greenwood et al. [24] have first published a technique, which they used to study the destruction of thiamin in cured pork luncheon meat compared with microbial destruction. This evaluation allows determining the only acceptable combinations of time and temperature that fall within the area of “cooked sterile,” all other combinations of time and temperature being unacceptable [25]. As we recently exemplified, similar evaluation can be applied to baked, fried, and roasted foods taking into account the formation of thermal-process contaminants and development of acceptable sensory properties [22]. In such case, the appropriate combinations of time and temperature would fall within the area “non-risky acceptable” [1,23].

Concerns over Thermal Processing of Foods

Thermal process induces several reactions in food products that may lead to impairment of nutritional quality of food, generation of toxic compounds such as acrylamide and furan, and formation of AGEs. Dietary intake of these exogenous compounds may cause their accumulation in bloodstream and in tissue proteins, then undergoing further reactions and several consequences in the body. Recent findings indicate that in vivo Maillard reaction processes are at least in part responsible for diabetic complications and the general aging process. The AGEs may contribute to the decline in tissue and organ function with age and are related chronic and degenerative diseases, such as diabetes, renal failure [26], atherosclerosis [27], Alzheimer’s disease, and Parkinson’s disease [28]. However, the mechanisms of these effects are largely unknown. Therefore, there is still a clear need for in-depth research not only to understand the in vivo effects of neo-formed compounds present in heated foods, but also to understand better the mechanisms and factors affecting their formation in foods.

References

[1] Gökmen V. A perspective on the evaluation of safety risks in thermal processing of foods with an example for acrylamide formation in biscuits. Qual Assur Saf Crops Foods. 2014;6(3):319–325.

[2] Studer A, Blank I, Stadler R.H. Thermal processing contaminants in foodstuffs and potential strategies of control. Czech J Food Sci. 2004;22:1–10.

[3] Skog K.I, Johansson M.A.E, Jagerstad M.I. Carcinogenic heterocyclic amines in model systems and cooked foods: a review on formation, occurrence and intake. Food Chem...

Produkt-Details

• Erscheint lt. Verlag: 31.7.2015
• Sprache: englisch
• Themenwelt: Studium ► 2. Studienabschnitt (Klinik) ► Pharmakologie / Toxikologie
• Themenwelt: Studium ► Querschnittsbereiche ► Prävention / Gesundheitsförderung
• Themenwelt: Technik ► Lebensmitteltechnologie
• Themenwelt: Wirtschaft
• ISBN-10: 0-12-802875-0 / 0128028750
• ISBN-13: 978-0-12-802875-9 / 9780128028759