Food and packaging

1.1 The importance of food processing

Food has been processed and packaged since the earliest days of man's history on earth. Meat and fish were salted, smoked and dried. Herbs were dried and stored for use as medicines. Alcoholic beverages were made from fruits and cereals. In the early days of traditional food processing the main aim was preservation to maintain a supply of wholesome, nutritious food during the year and in particular to preserve it for hungry periods, for example when hunting was poor. Food was seldom sold but traded and bartered.

While food processing still has the main objective of providing a safe nutritious diet in order to maintain health other aspects, particularly the generation of wealth for the producer and seller, have become increasingly important.

With the change from traditional to industrial food processing there has also been a change in the types of product processed. Traditional processors worked with foods that grew locally and the methods they developed were in harmony with the climate in which they lived. Only simple packaging using leaves, animal skins and pottery was possible and necessary to protect the food for its planned storage life. Nowadays non-traditional crops are grown all over the world. For example, the potato which originated in Peru, rice which came from Asia, and numerous fruits and vegetables are now grown away from their area of origin This together with consumer demand influenced by radio, advertising and television has lead to a demand for non-traditional foods that are not appropriate to the local environment. They need special processing and packaging to protect them for their required storage life.

While most people in the world still rely on traditional foods for their basic diet those in industrialized centres tend more and more to purchase processed and packaged foodstuffs for convenience. The increasing number of women who now work away from home adds additional pressure for such changes. Even people with a heavily traditional diet are demanding external products either as occasional treats, such as gassy drinks or basic commodities such as white sugar and flour.

To meet these demands the industrial food processing sector has emerged. Food and crop processing is generally considered to be the largest industry in most countries. Studies in several developing countries for example have shown that up to 25% of the urban population can be involved in making or selling ready-to-eat meals. While in developed countries food processing is almost totally carried out in large, automated factories small-scale food processing still remains a vitally important economic activity in the developing world. The small-scale food processing sector:

[] is a major source of employment,

[] adds value to crops by processing,

[] is a major source of food in the diet,

[] in some cases, by export, earns valuable foreign exchange,

[] provides opportunities for import substitution,

[] benefits a large number of poor people, such as farmers, packaging suppliers and vendors.

The small-scale food processing sector is however under increasing threat and competition from large manufacturers who, through economies of scale and better presentation and marketing, can put them out of business. The powerful large-scale food sector is also often able to influence government and international policies and laws and so prevent the small manufacturer from entering production or selling in a particular market.

Much of the customer appeal of foods produced in large factories in reality lies less with the food itself than with the appearance, presentation and advertising used to sell it Good packaging lies at the very heart of presentation and thus customer appeal. It is an area of vital importance for small and medium food manufacturers if they are going to continue to compete and expand.

1.2 What is good packaging?

Good packaging serves two purposes which are essentially technical and presentational.

Technical changes in packaging aim to extend the shelf-life of the product by better protecting the food from all the hazards it will meet in storage, distribution and use. Changing from one type of plastic bag to another for example may mean that less moisture from the atmosphere is absorbed into the food so extending the shelf-life. Making the bag re-closable in addition would mean that the customer could keep the food in good condition for longer in the home. If shelf-life is extended then it may be possible to market the product over a bigger area so increasing sales

Presentational aspects of packaging do not actually do anything to make the food keep longer or in better condition. Such packaging increases sales by creating a brand image that the buyer instantly recognises. It also aims to appeal to the customer in terms of shape, size, colour, convenience, etc.

The ultimate aim of good packaging is increased sales against any competition and thus improved income for the producer. This cannot be achieved without a cost. It is not only the direct cost of the packaging material that needs to be considered but other changes such as different processing systems, pun:: base of fillers, staff training, etc.

The small and medium-scale food manufacturer considering improvements to their existing packaging system face difficult decisions that will need careful thought and investigation One of the central problems is the impossibility of really knowing if the proposed changes will indeed result in increased sales that will have to be made to meet the costs involved. In addition, for most small producers, the choice is really not theirs but dictated by what kinds of packaging are locally available. In most cases it will not be possible to select the best type of package but only select the best of available alternatives.

Some of the positive and negative factors that need to be thought about are included in Table 1-1.

1.3 Environmental and economic aspects

As well as considering various types of industrial food packaging and their application, this book also briefly examines related areas such as re-cycling and economic aspects of the use of different materials.

With the increasing use of plastic packaging the whole subject of damage to the environment is becoming of increasing concern. One main problem is that plastic packaging is invariably cheaper than alternatives such as glass. If glass is given a monetary value of 10, then tins cost 6 to 8 units while plastic costs 3 to 8. The shift to plastic, at the present time, therefore appears unstoppable. However re-cycling and re-use of packaging can not only generate jobs and wealth but save energy and help to protect the environment A study carried out in Thailand, for example states that it would be possible to set up a $40 million a year industry based on recycling paper, cardboard and plastics.

In its final section this book considers some economic aspects of packaging changes. Not only must the direct cost of the pack be thought about but other associated costs such as equipment and training. Economic choices can be difficult and complicated A glass container, for example, is more expensive than a tin can. It can, however, be re-used, which may in the long run make it cheaper. The manufacturer would need to think about how many times the same bottle could be re-used, the costs of collection and costs involved in washing and preparing the returned bottles.

1.4 The aim of this book

It is hoped that this book will assist the small and medium food manufacturer to consider not only which packaging is best for their product but other related aspects. The whole package including its materials, label and shipping container should be considered as part of the overall business plan and not, as often happens, as an afterthought. The book is mainly written for entrepreneurs who wish to increase their sales and competitiveness by improving their business. Some of the technologies described may appear too large and costly for the very small cottage industry sector. In many cases, however, it is companies from this sector which, with advice and good management, have grown into well known brand names.

It is also hoped that this publication will be of interest to food research institutions, non-government organizations, development workers and extension workers who are involved in projects to improve the small-scale food processing industry sector.

It is believed that this book is somewhat unique in the bibliography of packaging, concentrating as it does on the small-scale application of packaging against a background of basic food technology.

Types of food and prevention of deterioration

In this chapter, one of the main reasons for packaging foods that was introduced in Chapter 1 – prevention of deterioration during storage – is covered in more detail. First the types of foods that are commonly produced by small to medium-scale processors are briefly described. This is followed by the main ways in which these foods spoil, together with other hazards that foods face during storage and distribution. The role of packaging in protecting foods against a variety of hazards is then described and the typical extension of shelf-life that arises from correct packaging is shown.

2.1 Food Products that are suitable for small-scale processing

Some processed foods are not suitable for manufacture on a small scale and others have no local or regional demand. The factors that determine whether a food is suitable for production in a particular location are complex and inter-related They are also specific to each production site. However broad guidelines on how to select the types of food that can be produced are as follows.

The selection of the type of food to process depends in part on the level of skill and experience of the staff that will do the production. Care should be taken with all low"id wet foods, including meat products (especially sausages, burgers and pies), vegetable products, milk products (except yoghurt, butter and ghee) due to the risk of food poisoning. These foods require strict hygienic processing and an understanding by the operators of the risks involved. They should not be produced by inexperienced or untrained people.

Other products require the use of expensive high-technology equipment that is not generally affordable or repairable by small-scale producers. Examples include any low"id canned foods (for example, canned meats, fish, vegetables, milk), hot-extruded snack foods, carbonated (fizzy) drinks, homogenized or UHT (Ultra-Heat Treated) milk, solvent-extracted cooking oils and irradiated foods (the last is not legal in some countries). Some foods (for example, some baked goods and sugar confectionery) require a degree of flair, skill, imagination and experience to produce interesting and appealing products. Again these would normally only be produced by trained or experienced staff.

It can be seen from the above considerations that packaging is only one of the many factors that should be taken into account when setting up a business to process foods for sale. However because of problems of availability of packaging materials in many developing countries the problem of packaging assumes great importance. The methods used to select a product and the scale of production may need to be modified to take this into account For example, the authors know of at least one food business in Africa in which the entrepreneur first found an available source of packaging materials and then designed a product that would suit it.

With these considerations in mind it is possible to analyse the factors that influence the likely success of a small food business and plan carefully to overcome any constraints. Typical questions that should be asked during the planning stage are shown in Table 2–1. In all cases, for a small business to be successful there should be:

[] a good demand for the food, either locally or as exports to neighbouring areas or countries,

[] supply of raw materials, ingredients and packaging materials,

[] affordable, easily operated, maintained and repaired equipment,

[] suitable infrastructure and facilities for processing and distribution of the selected food under hygienic conditions.

These considerations are shown as a 'decision tree' in Figure 2–1.

Taking these and other factors into account, Table 2–2 shows the foods that are commonly seen as suitable for production at the small scale. Short shelf-life products are those that are expected to be eaten within a few days of production. In general the following short shelf-life products are suitable for small-scale production because there is a good opportunity to add value to low-cost raw materials. There is often a good demand for such products and there are fewer packaging and distribution problems than occur with some other foods.

2.2 Types of deterioration

The section above indicated the types of food that can be processed on a small scale. The reasons for their selection are mostly concerned with the demand from customers (the popularity of a food) and the feasibility of small-scale production. If it is decided that there is a good demand for a food and that production is feasible, it is then necessary to make sure that processing adequately preserves the food for its expected shelf-life. An understanding of the various factors that cause food to deteriorate is helpful to ensure that the correct processing and packaging is selected. In this section the causes of deterioration of foods are first described and then the different roles of processing and packaging in preservation of the food are described.

The main causes of deterioration of foods are as follows:

[] micro-organisms,

[] enzymes,

[] chemical changes due to water, heat, metals, air or light,

[] contamination by soils, stones, insects etc.

[] physical (or mechanical) damage.

2.2.1 Micro-organisms

All fresh foods have micro-organisms on their surfaces, often in enormous numbers, and these can grow rapidly spoil foods. A main purpose of processing foods is to destroy unwanted micro-organisms. Packaging prevents recontamination and together processing and packaging prevent micro-organisms from spoiling the product during distribution and storage (that is to give the food the shelf-life that is expected).

Micro-organisms may be divided into general groups such as bacteria, yeasts or moulds, each of which may be further divided into sub-groups. Of the many microorganisms, the main types of interest are those that cause food spoilage and those that cause food poisoning.

When food is processed correctly, the number of spoilage micro-organisms and their activity is reduced and controlled at known levels. It is when there is a failure in processing conditions or packaging materials that spoilage micro-organisms can have an effect on the food. They can result in the food going mouldy, developing an off-smell or fermenting. The different types of spoilage depend to a large extent on the nature of the food and in particular its acidity and its moisture content.

Food poisoning is mostly caused by bacteria. These are also controlled by the acidity and moisture content of a food as shown in Table 2–3.

Food poisoning micro-organisms may grow in low-acid foods. Heat processing to 121°C for 15–50 minutes in jars or cans is required to destroy these micro-organisms.

Such heating requires the use of pressure cooking and detailed technical knowledge. For these reasons it is strongly advised that these foods are not produced by small-scale processors, especially as a first venture.

2.2.2 Enzymes

Enzymes are naturally occurring proteins that act on foods to cause changes in flavour, colour or texture. There are many hundreds of different enzymes but some of the more important spoilage changes include softening of fruits, rancidity of oils, browning of cut fruit or root crops and loss of green colour in vegetables. In general enzymes are either destroyed by heating or prevented from acting by changing the acidity or water content of the food.