Generally, the effects of microwave energy can be classified as either ‘macro￾scopic’ or ‘microscopic’. When the energy is used for heating food the effect is macroscopic and results in a specific heating pattern. However, the causes of certain features are due to microscopic effects, i.e. to physics at the atomic level

The continuous-flow heat process is a thermal heat-hold-cool process where the foodstuff to be treated is pumped in continuous flow through heat exchanger systems where it is heated to a desired temperature, held at that temperature for a pre-determined time, then cooled to around ambient temperature. After heat treatment, the product is then packaged in an appropriate manner. This process

Food quality, including colour, texture, flavour and nutritional value, is of key importance in the context of food preservation and processing. Colour, texture and flavour refer to consumption quality, purchase and product acceptability whereas the nutritive values (i.e. vitamin content, nutrients, minerals, health￾related food components) refer to hidden quality aspects. In conventional thermal processing, process optimisation consists of reducing the severity of the thermal process in terms of food quality destruction without compromising food safety

Preventing the loss of vitamins and nutrients in foods is a paramount concern at all stages of food processing involving heating. One example of the critical need for retaining vitamins is to nourish hospital patients who require vitamins to recover from the stress of illness or surgery.1 This issue has invoked recent studies

‘Genetically modified food’ has become the object of a heated debate by con￾sumer activists and replaced irradiation’s leading role as a target. In this debate the term irradiation is frequently confused with radioactive contamination, espe￾cially after the Chernobyl accident. The allegation is made that the nuclear indus￾try needs food irradiation badly in order to find some use for the waste from

The modern frozen food industry was started by Clarence Birdseye in America in 1925. As a fur trader in Labrador Birdseye had noticed that fillets of fish left by the natives to freeze rapidly in arctic winters retained the taste and texture attrib￾utes of fresh fish better than fillets frozen in milder temperatures at other times of the year. Frozen foods were available before Birdseye’s pioneering innovations, but they were of poor and uncertain quality. Birdseye’s insight was that speed of freezing is crucial to retain quality and he was the first to develop machinery

4.1 Introduction Minerals are the inorganic elements, other than carbon, hydrogen, oxygen and nitrogen, which remain behind in the ash when food is incinerated. They are usually divided into two groups – macrominerals and microminerals (or trace elements). The terms are historical in origin and originated at a time when the development of analytical equipment was still in its infancy and ‘trace’ was used to refer to components whose presence could be detected, but not quantified. Modern analytical equipment that allows determination of elements

6.1 Introduction: the problem of providing nutrition information Developments in nutrition research and improved scientific understanding of the relationship between diet and health have led to increasing interest in the nutri￾tional aspects of the food supply. This interest is shared by academics, health professionals, government officials, consumers and the food and supplement industries alike, although not always for the same reasons and generally at dif￾ferent levels of knowledge and understanding. Interest in nutrition, in respect of both total diet and individual foods, is second only to concern about food safety

3.1 Introduction Vitamins are classically defined as a group of organic compounds required in very small amounts for the normal development and functioning of the body. They are not synthesised by the body, or only in insufficient amounts, and are mainly obtained through food (Machlin and Huni, 1994). There are thirteen vitamins: four are fat-soluble, namely vitamins A (retinol)

8.1 Introduction The question of why it is necessary to improve the nutritional value of plant foods is one that at first hand might seem difficult to justify. What evidence is there that this is a problem? In the developed world there are no overt signs of malnutri￾tion even amongst strict