Agro-industries provide a means of converting raw agricultural materials into value added products while generating income and employment and contributing to overall economic development in both developed and developing countries.
Food processing converts relatively bulky, perishable and typically inedible raw materials into more useful, shelf-stable and palatable foods or potable beverages. Processing contributes to food security by minimizing waste and loss in the food chain and by increasing food availability and marketability. Food is also processed to improve its quality and safety.
Biotechnology as applied to food processing makes use of microbial inoculants to enhance properties such as the taste, aroma, shelf-life, texture and nutritional value of foods. The process by which micro-organisms and their enzymes bring about these desirable changes in food materials is known as fermentation. Fermentation processing is also widely applied in the production of microbial cultures, enzymes, flavours, fragrances, food additives and a range of other high value-added products.
Fermentation is often one step in a sequence of food processing operations, which may include cleaning, size reduction, soaking, and cooking. Microbes associated with the raw food material and the processing environment serve as inoculants in spontaneous fermentation, while inoculants containing high concentrations of live micro-organisms, called starter cultures, are used to initiate and accelerate fermentation in non-spontaneous or controlled fermentation processes. Microbial starter cultures vary widely in quality and purity.
Fermentation processing as practised in most developing countries is more art than science, and, in low-income economies, often makes use of a rudimentary technological base with poor process control, resulting in low yields and products of variable quality. Spontaneous fermentations and those which make use of "appropriate" starter cultures produced largely through backslopping (a process which makes use of samples of a previous batch of a fermented product as inoculants) are widely applied at the household and village level in developing countries. With increasing research and development, a number of precultured single or mixed strains of micro-organisms, called "defined starter cultures", have been developed and are being used by small manufacturers in their fermentation processing operations. Defined starter cultures are also imported by a number of developing countries for use in processing operations.
Traditional methods of genetic improvement such as classical mutagenesis and conjugation can be applied to improve the quality of microbial cultures. Hybridization is also used for the improvement of yeast strains. Recombinant gene technology is widely employed in research and development for strain improvement. While these techniques are common in developed countries, they are only now beginning to be applied in developing countries for the improvement and development of starter cultures. For example, random amplified polymorphic DNA (RAPD) techniques have been applied in Thailand in the molecular typing of bacterial strains for the production of a fermented pork sausage with differing flavours. The results of these analyses have led to the development of three different defined starter cultures, which are currently used for the commercial production of products with different flavour characteristics.
Genetically modified (GM) microbial cultures are used in the production of enzymes and various food processing ingredients. Rennet, which is widely used throughout the world as a starter in cheese production, is produced using GM bacteria. Thailand currently makes use of GM Escherichia coli as an inoculant in lysine production. Many industrially important enzymes such as a-amylase, gluco-amylase, lipase and pectinase, as well as bio-based fine chemicals such as lactic acid, amino acids, antibiotics, nucleic acid and polysaccharides, are produced in China using GM starter cultures.
Food safety is defined as the assurance that food will not cause harm to the consumer when it is prepared and/or is eaten according to its intended use, and food safety along the food chain includes the good agricultural practices that establish basic principles for farming (including aquaculture), soil and water management, crop and animal production, post-harvest handling and treatment, good manufacturing practices for storage, processing, and distribution to the consumer. Biotechnology is widely employed as a tool in diagnostics to monitor food safety, prevent and diagnose food-borne illnesses and verify the origins of foods.
The techniques applied in the assurance of food safety focus on the detection and monitoring of hazards. Biotechnological developments have led to the widespread availability of methods of identification that are more rapid and less costly than those based on conventional techniques. Polymerase chain reaction-based (PCR-based) and enzyme-linked immunoabsorbent assay (ELISA) methods are now applied in the detection of major food-borne pathogens. Genome sequence information, coupled with the support of advanced molecular techniques, have enabled scientists to establish defensive strategies to protect consumers from pathogens and provided industry with tools for developing strategies to design healthy and safe food by optimizing the effect of probiotic bacteria, the design of starter culture bacteria and functional properties for use in food processing. These advances have in turn led to more precise diagnostic tools and the ability to quickly develop efficient, specific and sensitive detection kits for new microbial strains. Kits are now also available for the detection of mycotoxins, which are a major biochemical hazard associated with pulses and grains, the raw material inputs for a number of traditional fermented foods in many developing regions. The identification of food ingredients and the origins of foods through traceability studies have also been enhanced by molecular methods.
For more information, see Current status and options for biotechnologies in food processing and in food safety in developing countries [ - 233 KB], prepared for the FAO international technical conference on Agricultural Biotechnologies in Developing Countries (ABDC-10) that took place 1-4 March 2010 in Guadalajara, Mexico.
Page Last Updated: July 2010