Importance of food processing and preservation
As Nigeria’s inflation rate recently surged to 19.64percent-the highest since September 2005(17 years)- it hasbecome imperative for those willing, to understand the significance of both food processing and preservation.
It is all because we live in a period of serious insecurity when many farmers in states, otherwise known for abundant food production (Benue, Niger, Zamfara, Ondo) cannot access their farms.
Even with other parts of the country where food production is high, there might be plenty of fruits, edible roots and vegetables wasting and rotting away at the rural areas due to lack of good access roads to take them to the urban centres for sale . They also lack the requisite knowledge of processing and preservation.
Furthermore, with unpredictable effects of climate change, foods that are seasonal should be subjected to modern processing and preservation techniques to retain their keeping qualities of nutrition, flavor, texture as well as sustain a long shelf-life.
We cannot therefore, afford to look down on the food industry which has the potential to diversify the economy from crude oil revenue.
In fact, the World Trade Organization ranks Nigeria as currently the largest food market in Africa, with significant investment in the local industry and a high level of imports. The food and beverage sector is estimated to contribute 22.5% of the manufacturing industry value, and 4.6% of the country’s GDP.
But in India, the food processing industry accounts for about 10% of the GDP and employs around 15 million people. The sector is multiplying and is estimated to reach a value of Rs. 2,58,000crore by 2022. There are many opportunities for investment in the food processing sector, and it offers good returns on investment.
At present, the global market of the processed food items is about 7 trillion dollars, which is gradually growing with time. Rapid globalization and industrialization are the major contributing factors for the progress of food processing industries in different countries.
An analysis of the UNIDO Industrial Statistics Database (2005) shows that food processing in developing countries is an auspicious component of the manufacturing sector, and the contribution of food processing industries to the national GDP increases with country’s national income. But what are foods to mankind?
Foods “are organic substances which are consumed for nutritional purposes. They come from plant or animal origin and contain moisture, protein, lipid, carbohydrate, minerals, and other organic substances. Foods undergo spoilage due to microbial, chemical, or physical actions. Nutritional values, color, texture, and edibility of foods are susceptible to spoilage”. But what cause their spoilage?
The factors are microbial, physical, excess water and sugar.
Perishable foods are often attacked by different microorganismswhich are molds, yeasts, and bacteria. Microbial spoilage is the most common cause of foodborne diseases. The growth of most microorganisms can be prevented or lingered by adjusting storage temperature, reducing water activity, lowering pH, using preservatives, and using proper packaging.
The key factors affecting physical spoilage are moisture content, temperature, glass transient temperature, crystal growth, and crystallization.Food spoilage due to physical changes or instability is defined as physical spoilage. Moisture loss or gain, moisture migration between different components, and physical separation of components or ingredients are the examples of physical spoilage. Therefore, foods are required to be preserved to retain their quality for longer period of time.
Crystal growth and crystallisation
Foods, which undergo slow freezing or multiple freeze, suffer severely due to crystal growth. They are subject to large extracellular ice growth. Rapid freezing forms ice within food cells, and these foods are more stable than slow freezing processed foods . To minimise large ice crystal growth, emulsifiers and other water binding agents can be added during freezing cycles.
Staling of sugar cookies, graininess in candies, and ice creams are the results of sugar crystallization.Foods with high sugar content can undergo sugar crystallization either by moisture accumulation or by increasing temperature. As a consequence, sugar comes to the surface from inside, and a gray or white appearance is noticed.
Sugar crystallization can be delayed by the addition of fructose or starch. Moreover, above the respective glass transition temperature, time plays a crucial role in sugar crystallization process of food items.
According to the functions to human body, food items can be categorized as: (a) body building and repairing foods, (b) energy-giving foods, (c) regulatory foods, and (d) protective foods. Depending on the nutrition value, food items can be classified as: (a) carbohydrate-rich foods, (b) protein-rich foods, (c) fat-rich foods, and (d) vitamin- and mineral-rich foods.
Food preservation as the way forward
The history of ‘Food Preservation’ dates back to ancient civilization when the primitive troupe first felt the necessity for preserving food after hunting a big animal, which could not be able to eat at a time.
Knowing the techniques of preserving foods was the first and most important step toward establishing civilization. Different cultures at different times and locations used almost the similar basic techniques to preserve food items.
Consumption of spoiled food can lead to illness and in the extreme situation to death. Considering the shelf-life, food items can be classified as perishable, semi-perishable, and non-perishable.
According to the authors of a research paper titled:‘A review on mechanisms and commercial aspects of food preservation and processing’ such as Sadat Kamal Amit, Md. MezbahUddin, RizwanurRahman, S. M. Rezwanul Islam &MohidusSamad Khan, the techniques to combat these spoilages are becoming sophisticatedin recent years
Conventional food preservation techniques are being used comprehensively throughout the world. These include drying, freezing, chilling, pasteurization, and chemical preservation. But scientific advancements and progresses are contributing to the evolution of existing technologies and innovation of the new ones, such as irradiation, high-pressure technology, and hurdle technology.
The processing of food has become highly interdisciplinary since it includes stages related to growing, harvesting, processing, packaging, and distribution. Therefore, an integrated approach would be useful to preserve food items during food production and processing stages.
The foods are usually ranked as perishable, semi-perishable and non-perishable.
Foods that have shelf- life ranging from several days to about three weeks are known as perishable. Milk and dairy products, meats, poultry, eggs, and seafood are the examples of perishable food items. If special preservation techniques are not apprehended, food items could be spoiled straight away.
Semi-perishable food items can be preserved for long time (about six months) under proper storage conditions. These include vegetables, fruits, cheeses, and potatoes.
Non-perishable natural and processed foods can be stored for several years or longer. Dry beans, nuts, flour, sugar, canned fruits, mayonnaise, and peanut butter are few examples of non-perishable foods.
This is the time for the ministry of agriculture, at the federal and state levels, food research centres and non-governmental organizationsto engage in enlightening the public, even using local languages on the benefits of food processing and preservation. These NGOs should reach out to graduates of agriculture, food science and technology for the mass sensitization. A stich in time will certainly save nine!