Food Chemistry: a Kazakhstan Perspective on the Maillard Reaction and Acrylamide Formation in Common Foods

The Maillard reaction is largely responsible for the colour, flavour, aroma and texture of fried, baked and roasted foods, including bread, biscuits, breakfast cereals and other foods made from wheat grain, French fries and crisps made from potato and a wide range of other popular foods. However, it also results in the formation of undesirable products, including the neurotoxin and probable carcinogen, acrylamide, and furans. Kazakhstan is a major wheat producer and exports wheat grain to many countries, including countries within the European Union. The European Commission has already issued "indicator levels" for the presence of acrylamide in food products. Although these are not regulatory limits, food producers strive to keep the levels of acrylamide in their products beneath the indicator levels in order to avoid intervention from food safety authorities and the associated bad publicity. Sourcing raw material with low acrylamide forming potential would enable food producers to achieve this without expensive changes to processesand this is likely to be an increasingly important issue for suppliers. This review describes the Maillard reaction, the evolving regulatory scenarios in Europe and the USA and the implications for Kazakhstan as a grain exporter

The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods

A recent workshop entitled The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods was held in Paris in December 2010, sponsored by the French National Centre for Scientific Research (CNRS) and by the journal Human Biology. This workshop was intended to foster a debate on questions related to the family names and to compare different multidisciplinary approaches involving geneticists, historians, geographers, sociologists and social anthropologists. This collective paper presents a collection of selected communications

Acrylamide-forming potential of cereals, legumes and roots and tubers analyzed by UPLC-UV

For directing scientists, consumers, industry and stakeholders on mitigation strategies, there is a need to understand the acrylamide-forming potential of important Indian foods. Flour obtained from total 16 varieties of 9 Indian cereals, legumes and roots and tubers was heated at 160 °C for 20 min, acrylamide was extracted and quantified by UPLC-UV. Acrylamide level was above the European Commission indicative value in potato- and cereal-based food products, it ranged from 3436.13 to 5562.56 μg/kg in roots and tubers (potato and sweet potato). Among the cereals, maize (2195.31 μg/kg) and wheat (161.12 μg/kg) had the highest and lowest contents, respectively, whereas rice, sorghum and pearl millet showed intermediate values. Among the 2 legumes, soybean contained higher acrylamide (337.08–717.52 μg/kg) than chickpea (377.83–480.49 μg/kg). Analysis of variance revealed that roots and tubers acrylamide was highly significantly greater than the content in cereals (p < 0.0001) and in legumes (p < 0.0001) while there was no significant difference between cereals and legumes (p = 0.443). These results support the combination of pulses and minor cereals (chickpea, soybean, millets and sorghum) in cereal-based foods for improving the nutritional value and reducing acrylamide formation

Effects of nitrogen and sulfur fertilization on free amino acids, sugars, and acrylamide-forming potential in potato

Nitrogen (N) fertilizer is used routinely in potato (Solanum tuberosum) cultivation to maximize yield. However, it also affects sugar and free amino acid concentrations in potato tubers, and this has potential implications for food quality and safety because free amino acids and reducing sugars participate in the Maillard reaction during high-temperature cooking and processing. This results in the formation of color, aroma, and flavor compounds, but also some undesirable contaminants, including acrylamide, which forms when the amino acid that participates in the final stages of the reaction is asparagine. Another mineral, sulfur (S), also has profound effects on tuber composition. In this study, 13 varieties of potato were grown in a field trial in 2010 and treated with different combinations of N and S. Potatoes were analyzed immediately after harvest to show the effect of N and S fertilization on concentrations of free asparagine, other free amino acids, sugars, and acrylamide-forming potential. The study showed that N application can affect acrylamide-forming potential in potatoes but that the effect is type- (French fry, chipping, and boiling) and variety-dependent, with most varieties showing an increase in acrylamide formation in response to increased N but two showing a decrease. S application reduced glucose concentrations and mitigated the effect of high N application on the acrylamide-forming potential of some of the French fry-type potatoes

Acrylamide-forming potential of potatoes grown at different locations, and the ratio of free asparagine to reducing sugars at which free asparagine becomes a limiting factor for acrylamide formation

Acrylamide is produced from free asparagine and reducing sugars during high-temperature cooking and food processing, and potato products are major contributors to dietary acrylamide intake. The present study analysed twenty varieties of potatoes grown at two sites (Doncaster and Woburn) in the United Kingdom to assess the effect of location of cultivation on acrylamide-forming potential. Analysis of variance revealed a full site by variety nested within type (French fry, boiling and crisping) by storage interaction for acrylamide (p < 0.003, F-test), reducing sugars and total sugars (p < 0.001, F-test). There was much greater free asparagine in potatoes grown at the Doncaster site compared with the Woburn site. Modelling of the relationship between the ratio of free asparagine to reducing sugars and the levels of acrylamide identified a value of 2.257 ± 0.149 as the tipping point in the ratio below which free asparagine concentration could affect acrylamide formation

Reducing the potential for processing contaminant formation in cereal products

Processing contaminants may be defined as substances that are produced in a food when it is cooked or processed, are not present or are present at much lower concentrations in the raw, unprocessed food, and are undesirable either because they have an adverse effect on product quality or because they are potentially harmful. The presence of very low levels of processing contaminants in common foods is becoming an increasingly important issue for the food industry, as developments in analytical techniques and equipment bring foods under closer and closer scrutiny. This review considers the formation of lipid oxidation products, hydrogenation of polyunsaturated fatty acids to prevent lipid oxidation and the associated risk of trans fatty acid formation. The formation of acrylamide in the Maillard reaction is described, as well as the genetic and agronomic approaches being taken to reduce the acrylamide-forming potential of cereal grain. The multiple routes for the formation of furan and associated chemicals, including hydroxymethylfurfuryl, are also described. The evolving regulatory and public perception situations for these processing contaminants and their implications for the cereal supply chain are discussed, emphasising the need for cereal breeders to engage with the contaminants issue

Growth of IGSC cracks in Type 304 stainless steel at 100 degrees C in an aqueous environment

Intergranular stress corrosion (IGSC) cracking has been observed in the primary coolant system of the Savannah River Site Reactors. There have been several cases during the over one hundred reactor-years of plant operating experience when IGSC cracks have grown through-wall and minor leaks have occurred. Approximately 7% of the heat affected zones of pipe-to-pipe butt welds show indications of IGSC cracking during ultrasonic testing (UT). Other piping and component areas, sensitized by flame washing or hot forming, have also developed IGSC cracks. The entire system was fabricated in the 1950's from Type 304 stainless steel. All joining was by the metal inert gas welding process. IGSC crack growth rates have been measured on compact tension specimens under controlled environmental conditions that encompass the observed conditions in the SRS reactor primary coolant systems. Growth rates were measured extending from less than 10{sup {minus}9} to approximately 10{sup {minus}5} millimeter per second. These growth rates bound the growth rates that have been inferred from a statistical analysis of UT indications. The UT data were collected since 1984 from weld heat affected zones in pipe-to-pipe butt welds in the SRS reactor primary coolant piping. Chloride and sulfate anions, dissolved oxygen, and peroxide have been identified as the water impurities that influence IGSC cracking in the SRS reactor primary coolant systems. A quantitative relationship has been established for susceptibility to IGSC cracking in terms of concentrations of these impurities and temperature. The heavy water reactor moderator and coolant is acidified with nitric acid to a pH of 4.7 to minimize corrosion of the aluminum cladding on the fuel elements

Statistical analysis of the DWPF prototypic sampler

The DWPF process will be controlled using assay measurements on samples of feed slurry. These slurries are radioactive, and thus will be sampled remotely. A Hydraguard{trademark} pump-driven sampler system will be used as the remote sampling device. A prototype Hydraguard{trademark} sampler has been studied in a full-scale mock-up of a DWPF process vessel. Two issues were of dominant interest: (1) what accuracy and precision can be provided by such a pump-driven sampler in the face of the slurry rheology; and, if the Hydraguard{trademark} sample accurately represents the slurry in its local area, (2) is the slurry homogeneous enough throughout for it to represent the entire vessel? To determine Hydraguard{trademark} Accuracy, a Grab Sampler of simpler mechanism was used as reference. This (Low) Grab Sampler was located as near to the intake port of the Hydraguard{trademark} as could be arranged. To determine Homogeneity, a second (High) Grab Sampler was located above the first. The data necessary to these determinations comes from the measurement system, so its important variables also affect the results. Thus, the design of the test involved not just Sampling variables, but also some of the Measurement variables as well. However, the main concern was the Sampler and not the Measurement System, so the test design included only such measurement variables as could not be circumvented (Vials, Dissolution Method, and Aliquoting). The test was executed by, or under the direct oversight of, expert technologists. It thus did not explore the many important particulars of ``routine`` plant operations (such as Remote Sample Preparation or Laboratory Shift Operation)

Sugars in crop plants

We review current knowledge of the most abundant sugars, sucrose, maltose, glucose and fructose, in the world's major crop plants. The sucrose-accumulating crops, sugar beet and sugar cane, are included, but the main focus of the review is potato and the major cereal crops. The production of sucrose in photosynthesis and the inter-relationships of sucrose, glucose, fructose and other metabolites in primary carbon metabolism are described, as well as the synthesis of starch, fructan and cell wall polysaccharides and the breakdown of starch to produce maltose. The importance of sugars as hormone-like signalling molecules is discussed, including the role of another sugar, trehalose, and the trehalose biosynthetic pathway. The Maillard reaction, which occurs between reducing sugars and amino acids during thermal processing, is described because of its importance for colour and flavour in cooked foods. This reaction also leads to the formation of potentially harmful compounds, such as acrylamide, and is attracting increasing attention as food producers and regulators seek to reduce the levels of acrylamide in cooked food. Genetic and environmental factors affecting sugar concentrations are described