Introduction
The paper presents the literature review on everyday chemistry and covers the following areas:
Food molecules.
Chemistry using kitchen chemicals.
Food safety from rotten products.
The paper used Google Scholar, WorldCat, Science Direct for literature search, and the key words were: food molecules, food chemistry, kitchen chemicals, food safety and rotten.
Types of Food Molecules
Every individual knows that food contains proteins, lipids and carbohydrates. These substances are the main nutrients and are responsible for energy supply for the body. There are numerous types, some are more complicated, some are simple; some are found in nature, and some are fully artificial. However, they are all vital and worth understanding.
Proteins are macromolecules built with simpler building blocks, aminoacids. There are about 20 aminoacids, and their general structure is R-CH(NH2)-COOH (Belitz et al., 2014). A molecule of aminoacid contain an aminogroup and a carboxylic acid group, joined to the carbohydrate chain. Instead of R, some aminoacids may have H atom, as glycine; some may have the carbohydrate chain (leucine and isoleucine), or more complicated functional groups (Belitz et al., 2014). The structures of some aminoacids are listed in Table 1.
Aminoacids are the building blocks for proteins. They combine by formation of the peptide link, and a macromolecule derives. Afterwards, the molecule forms hydrogen bonds, twists in a spring and wraps in a globule. The type of the protein is determined by sequence of aminoacids, and thus the number of proteins is abundant.
Lipids are commonly known as fats. The modern science does not offer the exact definition of lipids, yet the book in food chemistry formulates the approximate definition: 'a wide variety of natural products including fatty acids and their derivatives, steroids, terpenes, carotenoids, and bile acids, which have in common a ready solubility in organic solvents such as diethyl ether, hexane, benzene, chloroform, or methanol’ (Akoh & Min, 2008). The lipids have some common properties, namely, they are insoluble in water, yet soluble in organic solvents, and contain long-chain hydrocarbon groups in the molecules. The lipids come from the living organisms. The structures of the lipid molecules are complicated and include numerous functional groups; there are fatty acids, acylglycerols, phosphoglycierides, etc. (Akoh & Min, 2008).
Belitz et al. (2014) state that carbohydrates are ‘the most widely distributed and abundant organic compounds on earth’. Carbohydrates are derivatives from polyhydroxy-aldehydes (aldoses) or glyceraldehyde (ketoses). Carbohydrate molecules are found in numerous everyday products (Table 2).
The chemistry of food molecules is rather complicated. Molecules have various functional groups, can be macromolecules with various chemical properties. The food molecules are often found or synthesized in natural organisms.
The kitchen processes include much chemistry. All types of vinegar (synthetic, grape, apple, etc.) are acids. The baking soda is a base, as well as some types of mineral water. Baking process involves a chemical process, namely gas emission, which is a carbon dioxide formation due to baking powder decomposition. The components of baking soda are sodium hydrocarbonate or sodium phosphate (Singh, 2002). Kitchen cleaning processes (washing-up, floor cleaning, etc.) require application of washing agents. They contain surface-active additives, the molecules designed specifically to remove fats (Morgan & Clark, 2003). Many food preparation processes include chemical reactions. For example, potato boiling or porridge preparation are thermally induced reactions of starch and other macromolecular carbohydrates decomposition into biologically available form (Brown & Shedd, 2008). Hence, kitchen is full of chemical processes.
Food Safety from Rotten Products
Nowadays, people are concerned about the quality of food, since they believe that quality nutrition has significant influence on health and longevity. Various issues arise about food safety, and the problem of the rotten food is one of them. Typically, food is stored for rather long time at the storehouse before it is delivered to the supermarkets. As food is stored, the raw ingredients might get rotten, which results in mycotoxins production. The food products get rotten due to mishandling. The problem of rotten food is particularly common in countries with hot and humid climates. However, it may appear in any country (Schmidt & Rodrick, 2003). The customers’ protection is realized via setting the maximum allowable levels of the contaminants in food. The government is responsible for setting the standards (Lanser, 2015), while the food suppliers and distributors are obliged to keep them (Brimer, 2011). Recently, Kirezieva et al. (2016) indicated that the key role in food safety belongs to food cooperatives.
Conclusions
Food is inevitable part of our everyday life. Although there are various types of food, the food molecules belong to three groups: proteins, carbohydrates and lipids. These are complex macromolecules with various functional groups. The kitchen is a store of chemicals and chemical reactions, since almost all processes are performed with a reaction or with a chemical reagent application. Food safety is associated with chemical contaminants; mycotoxin is one of them that appears when the conditions of storage are violated.
Bibliography
Akoh, C. C., & Min, D. B. (2008). Food lipids chemistry, nutrition, and biotechnology. Boca Raton, CRC Press/Taylor & Francis Group.
Belitz, H.-D., Grosch, W., & Schieberle, P. (2014). Food chemistry. Berlin, Springer-Verlag.
Brimer, L. (2011). Chemical food safety. Wallingford, Oxfordshire, CABI.
Brown, C. L., & Shedd, B. (2008). Amazing kitchen chemistry projects you can build yourself. Chicago, Nomad Press.
Kirezieva, K., Bijman, J., Jacxsens, L., Luning, P. A. (2016) The role of cooperatives in food safety management of fresh produce chains: Case studies in four strawberry cooperatives, Food Control, 62, 299-308.
Lanser, A. (2015). Food science: you are what you eat.
Morgan, N., & Clark, J. O. E. (2003). Chemistry in action: the molecules of everyday life. New York, Oxford University Press.
Nollet, L. M. L. (2004). Handbook of food analysis. Physical characterization and nutrient analysis Vol. 1 Vol. 1. New York, Marcel Dekker.
Schmidt, R. H., & Rodrick, G. E. (2003). Food safety handbook. http://public.eblib.com/choice/publicfullrecord.aspx?p=226548.
Singh, K. (2002). Chemistry in daily life. Papua New Guinea, University of Papua New Guinea.
