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

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

Introduction: the principles of infrared heating Sir William Herschel discovered infrared – or heat radiation – in the 1800s when he was attempting to determine the part of the visible spectrum with the minimum associated heat in connection with the astronomical observations he was making

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

Modified atmosphere packaging (MAP) may be defined as ‘the enclosure of food products in gas-barrier materials, in which the gaseous environment has been changed’ (Young et al, 1988). Because of its substantial shelf-life extending effect, MAP has been one of the most significant and innovative growth areas in retail food packaging over the past two decades. The potential advantages and disadvantages of MAP have been presented by both Farber (1991) and Parry (1993), and summarised by Davies (1995) in Table 16.1

Extrusion cooking is a relatively recent form of food processing. Forcing material through a hole is the process of extrusion. Sausage extruders were devel￾oped in the nineteenth century as simple forming machines. Eventually pasta was produced in extruders. Flour and water were added at one end of the machine

Frying, especially deep fat frying, has become the most popular food prepara￾tion technology during the last five decades. The reason is that the preparation is easy even for less experienced cooks, the procedure is rapid, and the finished product is highly palatable. In the frying procedure, fat is the medium of heat transfer. Two main frying methods exist, namely shallow frying and deep frying

Vitamins, by their definition, are essential to health and have to be obtained from the diet on a regular basis because, with the exception of vitamin D, they cannot be produced by the body. In terms of medicine and nutrition, our knowledge of vitamins is relatively recent. Although James Lind discovered an association

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

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