ANALYSIS OF COMMONLY CONSUMED FOOD IN EASTERN NIGERIA FOR NUTRITIONAL AND ANTI-NUTRITIONAL VALUE

1.1INTRODUCTION

Food is any substance consumed to provide nutritional support for the body (Aguilera and David, 1999). Its components include water, carbohydrate, lipids, proteins, enzymes, vitamins, minerals, colours, flavours and food additives and it is ingested by an organism and assimilated by the organism's cell in an effort to produce energy, maintain life, or stimulate growth (Davidson, 2006).

The right to food is a human right derived from the International Covenant on Economic, Social and Cultural Rights (ICESCR), recognizing the “right to an adequate standard of living, including adequate food” as well as the “fundamental right to be free from hunger”. Almost all foods are of plant or animal origin. Other foods not from animal or plant sources include various edible fungi especially mushrooms used in the preparation of fermented and pickled foods like alcoholic drinks, leavened bread etc, water, salt and also blue–green algae such as spiralina (Campbell, 1998).

Many plants or plant parts are eaten as food. There are around 2,000 plant species which are cultivated for food, and many have several distinct cultivar. Seeds of plants are a good source of food for animals including humans, because they contain the nutrients necessary for the plant’s initial growth, including many healthful fats, such as omega fat. In fact, the majority of foods consumed by human beings are seed-based food (Carpenter and Finely, 2005).

Edible seeds include cereals (maize, wheat, rice etc), legumes (beans, peas, lentil etc) and nuts. Oilseeds are often pressed to produce rich oils- sunflower, flaxseed etc. Seeds are typically high in unsaturated fats and, in moderation are considered a health food, although not all seeds are edible. Large seeds, such as those from lemon, pose a choking hazard, while seeds from apples and cherries contain poison (cyanide) (Carpenter and Finely, 2005).

Fruits are the ripened ovaries of plants, including the seed within. Many plants have evolved fruits that are attractive as a food source to animals, so that animal will eat the fruits and excrete the seeds some distance away. Fruits therefore make up a significant part of the diet of most cultures. Some botanical fruits, such as tomatoes, pumpkin, and eggplants are eaten as vegetables (Davidson, 2006).

Vegetables are a second type of plant matter that is commonly eaten as food. These include root vegetables (potatoes and carrots), leaf vegetable (spinach and lettuce), stem vegetable (bamboo shoot and asparagus), and inflorescence vegetable (globe artichokes and broccoli) (Campbell, 1998).

Animals are used as food either directly or indirectly by the products they produce. Meat is an example of a direct product taken from an animal, which comes from muscle system or from organs. Food products produced by animals include milk produced by mammary glands which in many cultures is drunk or processed into dairy products (cheese, butter etc). In addition, birds and other animals lay eggs, which are often eaten and bees produce honey, reduced nectar from flowers which is a popular sweetener in many cultures. Some cultures consume blood, sometimes in the form of blood sausage, as a thickener for sauces, or in cured, salted form in time of food scarcity, and others use blood in stews such as civet (Lawrie and Lawrie, 1998).

Traditionally, food was obtained through agriculture. With increasing concern in agribusiness over multinational corporations owning the world food supply through patents on genetically modified food, there has been a growing trend toward sustainable agricultural practices. This approach, partly fueled by consumer demand, encourages biodiversity, local self-reliance and organic farming methods (Magdoff et al., 2000). Influences on food production include international organizations (example the World Trade Organization and Common Agriculture Policy), National Government Policy (or law) and war (Mason, 2005).

Animals, specifically humans, have five different types of taste; sweet, sour, salty, bitter and Umani. As animals have evolved, the tastes that provide the most energy (sugar and fats) are the most pleasant to eat while others such as bitter, are not enjoyable (McGee, 2004).

Water, while important for survival, has no taste. Fats on the other hand, especially saturated fats, are thicker and rich and are thus considered more enjoyable to eat. Sweetness is almost always caused by a type of simple sugar such as glucose or fructose or disaccharide such as sucrose, a molecule combining glucose and fructose (Mead, 1997). Sourness is caused by the taste of acids, such as vinegar in alcoholic beverages. Sour foods include citrus, specifically lemons, limes and to a lesser degree oranges (Mead, 1997).

Saltiness is the taste of alkali metal ions such as Na and K. It is found in almost every food in low to moderate proportions to enhance flavour, although to eat pure salt is regarded as highly unpleasant. Other than enhancing flavour, its significance is that the body needs and maintains a delicate electrolyte balance which is the kidney’s function (McGee, 2004).

Bitterness is a sensation often considered unpleasant, characterized by having a sharp, pungent taste. Dark, unsweetened chocolate, caffeine, lemon, rind, and some types of fruits are known to be bitter. Umani, the Japanese word for delicious, is the least known in western popular culture, but has a long tradition in Asian cuisine. Umani is the taste of glutamates especially monosodium glutamates or MSG (Mead, 1997). It is characterized by savory, meaty, and rich in flavor. Meat and other animal by-products, also mushrooms, salmon are described as having this taste.

Many cultures have a recognizable cuisine, a specific set of cooking traditions using various spices or a combination of flavours unique to that culture, which evolves over time. Many cultures have as well diversified their foods by means of preparation, cooking methods, and manufacturing. This also

includes a complex food trade which helps the culture to economically survive by way of food, not just by consumption.

While many foods can be eaten raw, many also undergo some form of preparation for reasons of safety, palatability, texture, or flavour. At the simplest level, this may involve washing, cutting, trimming, or adding other food or ingredients such as spices. It may also involve mixing, heating or cooling, pressure cooking, fermentation, or combination with other foods. Some preparation is done to enhance the taste or aesthetic appeal. Other preparations may help to preserve the food. Others may be involved in cultural identity, thus a meal is made up of food which is prepared to be eaten at a specific time and place (McGee, 2004).

The term ‘cooking’ encompasses a vast range of methods, tools and combinations to improve the flavour or digestibility of food. Cooking technique, known as culinary art, generally requires the selection, measurement, and combining of ingredients in an ordered procedure in an effort to achieve the desired result. The diversity of cooking world-wide is a reflection of the myraid nutritional, aesthetic, agricultural, economic, cultural and religious considerations that affect it (Carpenter and Finely, 2005). Cooking requires applying heat to a food which usually, though not always, chemically changes the molecules, thus changing its flavor, texture, appearance, and nutritional properties (McGee, 2004).

Certain cultures highlight animal and vegetable foods in their raw state (raw foodism). Salads consisting of raw vegetable or fruits are common in many cuisines. Sashimi in Japanese cuisine consists of raw sliced fish or other meat, and sushi often incorporates raw fish or sea food. Steak tartare and salmon tartare are dishes made from diced or ground raw beef or salmon, mixed with various ingredients and served with baguettes, brioche or frits (Smith, 2007).

Early food processing techniques were limited by available food preservation, packaging and transportation. This mainly involved salting,

curing, curdling, drying, pickling, fermenting and smoking (Jango-Cohen, 2005).

Food manufacturing arose during the industrial revolution in the 19th century. This development took advantage of new mass markets and emerging new technology, such as milling, preservation, packaging, labeling, and transportation (Jango-Cohen, 2005). At the start of the 21st century, a two-tier structure has arisen with a few international food processing giants controlling a wide range of well-known food brands. There also exists a wide array of small local or national food processing companies (Jango-Cohen, 2005).

Advanced technologies have also come to change food manufacture.

Computer-based control system, sophisticated processing and packaging methods, and logistics and distribution advances can enhance product quality, improve food safety and reduce costs (Humphery, 1998). The World Bank reported that the European Union was the top food importer in 2005, followed at a distance by the U.S.A and Japan. Food is now traded and marketed on a global basis. The variety and availability of food is no longer restricted by the diversity of locally grown food or the limitations of the local growing season (Smith, 2007).

Food marketing and retailing brings together the producer and the consumer. It is the chain of activities that brings food from “farm gate to palate” (Humphery, 1998). The food marketing system is the largest direct and indirect non-government employer in the United States (Humphery, 1998). It was reported on March 24, 2007, that consumers worldwide faced rising food prices. Reasons for this development include changes in the weather and dramatic changes in the global economy, including higher oil prices, lower food reserves, and growing consumer demand in China and India (Howe and Devereux, 2004). However, the Food and Agriculture Organization projects that consumers still have to deal with more expensive food until at least 2018 (FAO, 2010).

Food deprivation leads to malnutrition and ultimately starvation. This is often connected with famine, which involves the absence of food in entire communities. This can have a devastating and widespread effect on human health and mortality. Rationing is sometimes used to distribute food in times of shortage (Howe and Devereux, 2004).

Starvation is a significant international problem. Approximately 815 million people are undernourished, and over 16,000 children die per day from hunger- related causes (Humphery, 1998). Food deprivation is regarded as a deficit need in Maslow’s hierarchy of needs and is measured using famine scales (Messer et al., 1998).

Food aid can benefit people suffering from a shortage of food. It can be used to improve peoples lives in the short term, so that a society can increase its standard of living to the point that food aid is no longer required (Kripke, 2005). International efforts to distribute food to the neediest countries are often coordinated by the World Food Programme (Kripke, 2005). Food borne illness, commonly called “food poisoning”, is caused by bacteria, toxins, virus, parasites and prions. Roughly seven million people die of food poisoning each year, with about 10 times as many suffering from a non-fatal version (Messer et al., 1998). Food borne illness could be by cross-contamination of ready-to-eat food from other uncooked foods or improper temperature control, improper storage, toxic substances inherent in food regularly eaten, and even storage in an unsafe container. In more recent years, a greater understanding of the causes of food-borne illness has led to the development of more systematic approaches such as the Hazard Analysis and Critical Control Point (HACCP), which can identify and eliminate many risks. Some people have allergies or sensitivities to foods which are not problems to most people. This occurs when a person’s immune system mistakes a certain food protein for a harmful agent and attacks it. About 2% of adults and 8% of children have a food allergy.

Healthwise, human diet was estimated to cause perhaps around 35% of cancer in a human epidemiological analysis by Richard Doll and Richard Petoin, (1981) (http://www.niaid.nih.gov.publications/pdf/foodalergy.pdf).

Infact between the extremes of optimal health and death from starvation or malnutrition, there is an array of disease states that can be caused or alleviated by changes in diet. Deficiencies, excesses, and imbalances in the food we eat can produce negative impacts on health.