Additives and Preservatives Used in Food Processing and Preservation, and Their Health Implication
Chapters One
Objectives of study
- To assess food additives usage in Nigeria.
- To identify the health implications of additives used in Nigeria
- to identify the prospects of food additives.
CHAPTER TWO
FOOD PRESERVATION
Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), or other micro-organisms (although some methods work by introducing benign bacteria or fungi to the food), as well as retarding the oxidation of fats that cause rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut during food preparation.
Maintaining or creating nutritional value, texture and flavor is an important aspect of food preservation, although, historically, some methods drastically altered the character of the food being preserved. In many cases these changes have come to be seen as desirable qualities with cheese, yogurt and pickled onions being common examples. The following section discusses additives as a food preservation method.
Additives
additives is the process by which an object is exposed to radiation. The exposure can originate from various sources including natural sources. The term most times refers to ionizing radiation, and depends on the level that fits a specific purpose, rather than radiation exposure to normal levels of background radiation.
Food additives is a food preservation method which involves the process of exposing foodstuffs to a source of energy capable of stripping electrons from individual atoms in the targeted material (ionizing radiation) (Anon, 1991). The radiation can be generated electrically using beta particles (high-energy electrons) or the use of gamma rays (emitted from radioactive sources as cobalt-60 or caesium-137). This treatment is used to preserve food, reduce the risk of food borne illness, prevent the spread of invasive pests, delay or eliminate sprouting (as in tubers) or ripening (as in fruits), increase juice yield and improve re-hydration and at higher doses induces sterility.
Food additives is criticized because additives can initiate chemical changes that are different than those that occur when heating food (unique radiolytic products). Some people worry that there is the potential of danger from these substances. Research has discovered that one family of chemicals is uniquely formed by additives, and this product is nontoxic. When heating food, all other chemicals occur in a lower or comparable frequency (Anon, 1994). Others criticize additives because of confusion with radioactive contamination or because of negative impressions of the nuclear industry.
The regulations that dictate how food is to be irradiated, as well as the food allowed to be irradiated, vary greatly from country to country. In Austria, Germany, and many other countries of the European Union only dried herbs, spices, and seasonings can be processed with additives and only at a specific dose, while in Brazil all foods are allowed at any dose (Kume et al., 2009).
additives is also used for non-food applications, such as medical devices, plastics, tubes for gas pipelines, hoses for floor heating, shrink-foils for food packaging, automobile parts, wires and cables (isolation), tires, and even gemstones.
It is permitted by over 50 countries including Nigeria (Liberty et al., 2013) with around 500,000 metric tons of foodstuffs processed annually worldwide (Adu-Gyamfi, 2002).
- The Process of Food additives
In the process of food additives, most of the radiation passes through the food without being absorbed (Roberts et al., 1995). The small amount that is absorbed is capable of destroying any insects on grains, food produce or spices; extend shelf life and prevent fruits and vegetables from ripening too fast. The absorbed dose is primarily a function of the duration of exposure and the distance from the source. The food is exposed to effective amounts of ionizing radiation so that pathogens, pests, and spoilage organisms can be destroyed. The organisms are destroyed by the electrons breaking the bonds that hold the pathogen’s DNA together. Damage to the DNA disables the organism’s ability to grow or multiply. The radiation dose to which food is exposed is based on extensive research to ensure the destruction of pests and pathogens while at the same time preserving the wholesomeness of the food.
The food additives method is a cold treatment that achieves its effects without raising the food’s temperature significantly, leaving the food closer to its original state. Even spices which are treated for 2-4 hours remain essentially at room temperature. By not using high temperatures, food additives minimizes nutrient losses and changes in food texture, color, and flavor.
CHAPTER THREE
AN OVERVIEW OF THE PRINCIPLES AND EFFECTS OF ADDITIVES ON FOOD PROCESSING AND PRESERVATION
PRESERVATION
According to the Codex General Standard for irradiated Foods, ionising radiations recommended for use in food processing are: (i) Gamma rays produced from the radioisotopes cobalt-60 (60Co) and cesium-137 (137Cs), and (ii) Machine sources generating electron beams (maximum level of 10 MeV) and x-rays (maximum level of 5 MeV).
Both cobalt-60 and cesium-137 emit highly penetrating gamma rays that can be used to treat food in bulk or in its final packaging. Cobalt-60 is, at present, the radioisotope most extensively employed for gamma additives of food (Steward, 2001). Machine-sourced ionising radiations have the advantage that no radioactive substance is involved in the whole processing system. Electron-beam machines use linear accelerators to produce accelerating electron beams to near the speed of light. The high-energy electron beams have limited penetration power and as such can only be used on foods of relatively shallow depth (Steward, 2001), or on foods less than 10 centimeters (cm) thick because of the limited penetrating capacity of the electron beams.
Electron beams can be converted into various energies of x-rays by the bombardment with a metallic target. Although x-rays have been shown to be more penetrating than gamma rays from cobalt-60 and cesium-137, the efficiency of conversion from electrons to x-rays is generally less than 10% and this has hindered the use of machine sourced radiation so far (ICGFI, 1999).
CHAPTER FOUR
THE PROSPECTS AND HEALTH IMPLICATIONS OF ADDITIVES IN NIGERIA
The Prospects
One of the most effective strategies that could be used in solving the problem of population-food imbalance especially in the developing countries where a quarter of the harvested food is said to be lost due to wastage and spoilage (NAS, 1978); is to drastically reduce the amount of food lost in the post-harvest system. Several forms of research has already been carried out by some Nigerians from various fields of discipline to ascertain the efficacy of the food additives in reducing or curbing sprouting or spoilage of some basic Nigerian foodstuffs such as yam, water yam (James et al., 2012), onions (Agbaji et al., 1981), sesame seeds (Fapohunda et al., 2012) etcetera. The results and conclusions drawn from these investigations has shown time and time again that food additives will find good use in the country if it is properly and adequately utilized. Being aware of that, Nigeria has developed a research and development programme in various fields of nuclear science including food additives. This section tries to describe the research and development activities carried out on food additives in Nigeria.
CHAPTER FIVE
Conclusions and recommendation
Recommendations
If food additives is to gain widespread usage in Nigeria, then the problems highlighted in the previous chapter needs to be addressed. This section will attempt to proffer possible solutions to the problems highlighted in the previous chapter.
Lack of Adequate Equipments
The fact that Nigeria has just one functional additives facility is a setback. If Nigeria has to measure up with other developed countries as regards the use of additives for the preservation of food and other materials commercially, then she will need to begin setting up more additives facilities at strategic locations, so as to enhance easy accessibility from all parts of the country. To address the above issues properly, a system must be put in place that brings public and private sectors together for active interaction. A cue could be taken from the Food Corporation of India, which has played a significant role in transforming the Indian food economy. It operates through a countrywide network of institutions and infrastructures at zonal, regional and district level (Oyewole and Oloko, 2006). Active co-operation between the relevant government agencies and the private sector will in more ways than one hasten the creation or construction of more additives facilities at strategic geo-political zones and locations in the country, in order to make this technology accessible to potential users.
Once these structures are put in place, it will also go a long way to address the issue of transportation. Once GIFs are available at strategic geo-political zones and locations in the country, places where production is high, then the constraint of moving food produce over long distances will be considerably minimized.
Cost Arising From the Actual Service
There is also need for production incentives in terms of favorable pricing linked with efficient marketing facilities, if losses are to be reduced. In Nigeria, however, incentives are generally minimal or non-existent. There is no provision for cushioning farmers against periods of sharp price fluctuations. The issue of price assurance must be addressed so that the farmer can increase production to levels that will ensure stability of supplies to meet both normal and emergency requirements.
Also, the slight increase in price for irradiated food is insignificant considering the benefits the consumers get in terms of convenience, improved hygiene of the food, quantity and availability (Frenzen et al., 2000).
Lack of Adequate Sensitization
To solve the issue of inadequate sensitizations, there should be a platform for extension agents to actively disseminate information on improved storage techniques to farmers in the rural areas through use of mass media (e.g. radio/television) and farmers groups. Available sources of storage technologies should also be communicated to farmers by the zonal extension service.
Also, the use of some modern storage technologies requires specialized skills and technical know-how which farmers are lacking. Farmers should be trained on the use of these improved storage methods such as storage by additives. Institutions, the government and other organizations should arrange regular workshop training for farmers and those who operate agricultural machinery, in a bid to educate and familiarize them with this technology, and to encourage its adoption.
Transport System
Also necessary, is the Construction of Feeder Roads. These must be built to convey the large amounts of farm produce now wasting away in the fields because of lack of transport facilities. This problem can also be solved setting up more additives facilities at strategic locations, so as to enhance easy accessibility from the farms to the facility.
CONCLUSION
This report has attempted to discuss the prospects and problems associated with the use of food additives as a food preservation method in Nigeria. Food additives is a food preservation method which involves the process of exposing foodstuffs to a source of energy capable of stripping electrons from individual atoms in the targeted material (ionizing radiation) (Anon, 1991). This method of food preservation can be referred to as a more advanced form of food preservation. Some school of thought criticize the use of additives for food preservation because of the negative impressions of the nuclear industry, and this has made additives one the most investigated forms of food preservation. Food additives has being endorsed by the World Health Organisation (WHO), and is currently being used in over 40 countries and approximately 500,000 tons of food items are irradiated yearly all over the world.
The common sources of ionizing radiation recommended by the codex general standard for use in food additives include;
Gamma rays produced from the radioisotopes cobalt-60 (60Co) and celsium-137 (137Cs) Machine sources generating electron beams and x-rays.
Machine sources have the advantage that no radioactive substance is involved, and it can be switched off and on with the just the push of a button.
Though food additives brings about some chemical changes in food, these changes are not different from those that occur when food is exposed to other forms of food processing or probably when food is cooked. However based on hundreds of scientific tests, there is a broad agreement among scientists and health agencies that these changes do not pose a human health issue.
Food can be irradiated either in its prepackaged form or its packaged form depending on the type of food product. The food products are exposed to ionizing radiation over a particular period of time, to achieve the desired and recommended dose rate. This process is carried out in specially designed and shielded facilities so as to avoid incidences of environmental pollution.
In Nigeria, food additives has not gone beyond the experimental stages. But with the present efforts of some relevant government agencies such as the Small and Medium Enterprise Development Agency of Nigeria (SMEDAN) and Nigeria Atomic Energy Commission (NAEC), and also some promising research from various scholars in Nigeria, there is a promising indicator that this technology will soon reach its stage of commercialization in Nigeria.
The problem of population-food imbalance, caused by food wastage and spoilage is common to most developing nations of the world including Nigeria. One of the effective strategies that can be used in solving this problem is to reduce the amount of food lost in the post-harvest system. Several investigations by Nigerian scholars have confirmed that food additives will adequately help reduce spoilage and wastage of some basic food products in Nigeria.
The Nigerian government under the directive of the NAEC also shares the same view and as such have begun to put some structures in place so as to enable meaningful research work on the usefulness of this technology on Nigerian food products and to facilitate the smooth introduction of this technology in Nigeria. It is in this light that the NAEC created six nuclear research centers among which is the Nuclear Technology Centre (NTC), Sheda Science and Technology Complex, for research and development (Agedah, 2014), which houses a 340 kCi Co-60 Gamma additives Facility (GIF). This facility is currently being utilized by various researchers in the country.
Despite all these efforts, there are still some critical issues that need to be addressed for the smooth introduction of this technology in Nigeria. These problems include; lack of adequate additives facilities, cost of procuring this service, cost of setting up more additives facilities, lack of adequate sensitization etcetera.
If additives is to gain widespread use in, then the highlighted problems would need to be adequately tackled.
REFERENCES
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