“Forensic” is derived from the Latin, with its meaning referring to law. Hence the definition of forensic science hinges on this meaning as a branch of science that applies scientific principles and methods to public domain cases related to criminology and civil law. It deals with the whole process of gathering and examining information that can be presented as evidence in courts of law, to enable the execution of law enforcement in relation to criminal or civil laws.
The application of science and scientific principles to point beyond reasonable doubt to criminals and crimes has been in existence for centuries. In the past, the strategy to catch and deal with criminals had many limitations, mainly due to the lack of standardized methods, which led to numerous flaws that allowed criminals to evade punishment due to lack of sufficient evidence. In those ancient times, criminal acts were investigated based on the testimonies of witnesses and from personal confessions. There was no application of any of the scientific methods and techniques which make use of the scientific principles and concepts that are available to us today. In these modern times, forensic science, as it is applied in a diverse number of fields, employs highly sensitive and selective methods and techniques in analyzing evidence obtained at a crime scene, even where the specimen presented as evidence is at the trace level. Among the areas of disciplines which make use of scientific principles to investigate foul play are in foods and foodstuffs.
Given its importance to life, food will remain the most fundamental of our needs, because it is the source of all the energy needed to carry out life’s activities, including those which define the very characteristics of life. Food is essential to our physical well‐being, and it is the main item that all the cares of the day are invested towards. Food is the source of energy needed for tissue repair, muscle movement and also plays an important role in the whole process of growth. One may dare to say that without food there is no life! On the other side of the same coin, food that is unfit for human consumption may be used to target and terminate life. For this reason, food is one of the items prone to be used or abused to threaten life.
There are many ways and instances where food composition has been compromised or tampered with, bringing negative effects to consumers. Normally the introduction/incorporation of either microbial (bacterial, fungal or viral) metabolites or chemical agents, compromises the safety of food that is meant for consumers and this constitutes a food fraud case. There are two main types of fraudulences as far as food is concerned. One such example involves a complete replacement of the entire authentic food product with a substitute product. This kind of fraud is termed as “crude fraud” and in many cases it involves expensive, highly moveable items such as alcoholic beverages. Another type of fraud that is practiced within the food business/industry is known as “sophisticated fraud”, in which some food components are manipulated by either substituting quality ingredients with inferior ones or the entire food product is subjected to dilution (e.g. addition of water to milk, brine to frozen meat, glycerol to wine, etc.).
Again, of late, there have been many food scares, scandals and fraud cases reported widely that not only pose a large risk but have also caused loss of life globally. For example, the advent of genetic engineering technology in food as well as in food industries has introduced genetically modified foods/organisms (GMO), which could pose a potential risk to human existence, though not yet proved scientifically. Apart from the GMO issue, there have been plenty of other incidences, such as the outbreak of bird/avian and swine flu (H1N1, H5N1, H7N3, H7N7, H7N9, H9N2, etc.), and the outbreak of foot‐and‐mouth disease and bovine spongiform encephalopathy (BSE), also known as Mad Cow Disease. Other microbes, such as the strain of Escherichia coli (E. coli O157), are harmless resident flora in the gut of cattle but can cause disease in humans through the consumption of meat and meat products containing this bacteria strain. Clostridium botulinum, a spore‐forming bacterium, produces botulism toxins that are fatal to consumers of food items containing this toxin.
There have also been numerous reports linking the incorporation of illicit food additives (which in some cases are not listed on the labels properly) in food products, and other malpractices by food producers and food industries. These reports have alerted the public and raised the awareness of the composition of food products, thus the high demand for tighter scrutiny, guidelines and regulations on additives in foods.
Incidences related to foul play in foods in terms of processing, labeling, distribution, food poisoning and intoxication, etc., have signaled law enforcers, nutritionists and health bodies to introduce more laws, set regulations and draw up guidelines to safeguard the health and well‐being of consumers. Due to this, foodstuffs and food products are now analyzed and investigated to see if they comply with the requirements set for quality, nutritive contents, adulteration, compliance against legally set guidelines and regulations, and also whether the labeling requirements are accurate. These considerations are also meant for research and development purposes to improve the quality of food products.
All governments, as well as national and international agencies, have set regulations, guidelines and recommendations in place to ensure the quality and safety of foods and food products. Such regulations, guidelines and recommendations have to be observed and adhered to by all suppliers and food industries responsible for providing consumers with foods. The enforcement of rules and regulations ensure the wholesomeness and safety of foodstuffs, and satisfy the public need which insists that food suppliers and food industries inform consumers about the state and nutritional composition of their food products, to enable individuals make their choices with regard to their preferences or to provide an environment with fairness, in cases where there is more than one competing company or entity, to avoid any possibility of economic fraud.
Food regulatory bodies, and national and international agencies, have specified some standards to be observed by food suppliers and food industries with regard to quality and compositions of food products. Some of these standards are legally extremely strict and it is mandatory that they are adhered to by all responsible parties, while some others tend to be more flexible.
The strict standards which are mandatory include the quality standards in which quality specifications regarding stability, types and classes of color, mass/or volumes, tenderness, etc are being considered. Standards of identity are also mandatory by regulations and specifications regarding type, composition, ratio and amounts of various ingredients required for a specified food product, which must be made known so that where a threshold limit is set, the guidelines should be clear that it has not been violated. For example, in some foodstuffs, levels of fats are controlled by law and should not exceed certain specified levels. The standards of fill‐of‐containers are also mandatory, in which case a measure of fill/mass has to be known to avoid fraud or treachery of any sort. In this category of standards, the means or how to ascertain the fill/mass has to be made known as well. Flexible standards may as well include grading of food products.
Authorities responsible for food regulations also enforce a requirement that the origin and authenticity of food products be correctly included in the labeling, together with the labeling specifying food ingredients and their composition. This information is vital for the prevention of economic fraud and for ensuring that the correct type of food is supplied to the target people. For example, people of a particular religious group, or those who need food with certain ingredients, for instance, fat, sugar, salts, etc., at certain amounts. For this reason, food and food products need to be analyzed and ascertained for their safety and quality.
In some cases, microbial attack on food not properly stored leads to the presence of toxic metabolites. Therefore, storage conditions and techniques are some of the issues that are scrutinized, especially for the types of foods and food products that need to be transported to distant places or those which are not to be consumed immediately.
The presence of undesirable chemical and biological molecules prompts the enforcement of monitoring schemes to ensure safety and quality of foods and food products. The monitoring scheme has to have scientific methods and techniques in place that are sensitive and selective enough to exclude all other undesirable or non‐targeted matrix molecules as well as to enrich the analytes of interest. The enrichment step is necessary because. in many instances, the target analytes are in trace amounts or dissolved/incorporated into a larger mass/volume of food products which causes the analyte to be highly diluted.
Normally, the analytical strategy involves the development of highly selective and sensitive methods that are capable of thorough clean‐up and pre‐concentrate the analytes before their introduction into the analytical system, such as HPLC, GC, AAS, ICP, etc. The data obtained from these analyses are meant to provide information regarding the safety of the foodstuffs or if a particular food item contains harmful microbes such as Salmonella or their metabolic by‐products, or the presence of chemical molecules such as pesticide residues, or even the presence of some other foreign contaminants. Foodstuffs for human consumption imply that they are free from all such things, and food manufacturers as well as suppliers have a duty to ensure food safety by carrying out routine analysis of food products. Moreover, food industries are at all times faced with stiff competition from each other and are thus obliged to perform these routine checks to remain competitive and win more markets.
Generally, strict regulations and guidelines necessitate food industries to use methods and techniques that are reliable and which are capable of providing low detection and quantification limits to be able to comply with guidelines and regulations. Testing and analysis should normally be done strategically, before, during and after the manufacturing and in some cases, long after the manufacturing to ensure stability under different sets of storage conditions, such that the final food product possesses the same properties and qualities including shelf life, appearance (color), flavor and texture in addition to chemical, physical and biological properties.
However, naturally foodstuffs do undergo deterioration and spoilage over time and under some conditions where the chemistry of raw material ingredients unpredictably changes, thus affecting the whole food product. Under such circumstances, what is required is to understand the chemistry of the ingredients and the mechanism by which each plays its role in relation to the final food product. This knowledge helps to predict the behavior of various ingredients under different sets of conditions and thus control the production processes accordingly, in order to avoid unnecessary food deterioration. For example, food color of some products, such as chips made from potatoes, is highly dependent on the concentrations of reducing sugars present in the potatoes during the manufacturing processes. If the reducing sugars are present at high concentrations in the potatoes, it will cause more browning of the potatoes as time goes on (Msagati, 2012). This implies that those responsible in the preparation have to ensure that the potatoes used have the required concentration of reducing sugars to avoid color changes with time or during the frying process.
Currently, the global trend with respect to attitudes towards foods has been highly shaped by the opinion of consumers, due to changes in consumer preferences towards the types of foods that are seemingly healthier. In some cases the origin of food, cost or those seen as exotic, have been an important factor for consumer preference. This trend has shaped the whole food industry, which has to conduct research and development for either the improvement of the existing products or formulate new food products that satisfy the changing demand of consumers. In this scenario, food industries engage in research activities that investigate the mechanisms of how various food ingredients and components work and also the roles they play individually or when introduced to others. The investigation process also encompasses the whole industrial processes that take place or occur during food manufacturing and how they affect the quality and composition of food, even after a long period of time when subjected to various physical/environmental conditions such as temperature, humidity, storage, etc. In other words, food development of new products always requires the knowledge of the food ingredients as well as the processing operations and how they interact to give food the desired quality.
On the other hand, the analytical procedures required by food analysts need to establish factors that will reveal the information about composition, physico‐chemical properties of food, etc. This is due to the fact that food components (composition) tell how safe or nutritious the food is. The composition of many foods is complex, being made up of many different ingredients (vitamins, proteins, carbohydrates, fats, fibers, minerals, etc.) and in different ratios, both in terms of the types of atoms (e.g. C, H, N, O, S, Na, Se, etc.) and molecules (e.g. H2O, sugars, essential fatty acids such as omega‐3, essential amino acids, etc.). For food manufacturers and distributors to comply with regulations, they are thus obliged to declare compositions, ratios, levels and types of all the ingredients in their products.
Similarly, the attributes of foods in terms of their physical characteristics as measured by their rheological properties (stability, taste, color/optical, flavor, etc.), are very important to consumers, as they affect their appeal and choices. This shapes the food industry since it requires that foods and food products be designed to contain the qualities that will appeal to consumers and at the same time comply with regulations and guidelines. The design and operating conditions must also ensure food stability under all conditions without affecting attributes such as color, smell/odor, feel or texture. Moreover, the design and operation processes during food manufacturing have to be such that they maintain the structure of the food and food products.
Food analysis will therefore require different types of analysis, methods and techniques, due to a variety of information and measurements that may be needed to ascertain the quality and safety of a particular food product. There are many sources where the information for the appropriate technique for measuring or ascertaining a particular food property can be obtained. For instance, there are specific books, journal publications and suppliers of instruments, reagents, chemicals and materials used in the analysis of foods. There are also official methods and techniques published by authorized bodies that deal with food analysis and quality assurance, as well as public domains such as the World Wide Web (internet).