Industrial Drying Of Foods

Drying is fundamental step in the maufacture of many foods. Although its primary function is to remove appropriate quantities of moisture it is, in many cases, also responsible for imparting the characteristic qualities that distinguish one product from another. This book provides a fundamental understanding of moisture transport in the drying of foods and of the physical and chemical changes that occur during drying. A comprehensive description and assessment of the different types of dryers available to the industry are given and factors effecting the operation, control and selection of dryers are described. The combination of practical information supported by relevant theory makes this an essential volume for industrial food engineers, those involved in equipment manufacture, process plant design and new product development in all food sectors where dried foods are used. It will also be of interest to academic researchers in this aspect of food engineering.

Drying is traditionally defined as that unit operation which converts a liquid, solid or semi-solid feed material into a solid product of significantly lower moisture content. In most, although not all, cases it involves the application of thermal energy, which causes water to evaporate into the vapour phase. In practice, this definition encompasses a number of technologies which differ markedly in, for example, the manner in which energy is supplied to the foodstuff and in which product is transported through the dryer. Depending on the dryer type, the residence time may vary from a few seconds to several hours. Dryers designed to handle liquid feedstocks are naturally quite different from those intended to process moist solids. Even within these two broad categories, however, many distinct varieties of dryer have evolved to meet specific process ing needs. The dryer is frequently the last processing stage in the manufacture of a dehydrated food product. As such, it may not only bring about the desired reduction in moisture content but may also have a significant effect on a number of other properties, such as flavour, colour, texture, viability, and nutrient retention, for example. These properties, which are generally considered to affect the perceived quality of the end product, are often influenced by the temperature- moisture content-time profiles experienced by the foodstuff as it moves through the dryer. The underlying chemistry and physics are highly complex and, broadly speaking, only poorly understood.

Drying is by far the most useful large scale operation method of keeping solid foods safe for long periods of time, and is of fundamental importance in most sectors of food processing. Drying operations need to be precisely controlled and optimized in order to produce a good quality product that has the highest level of nutrient retention and flavor whilst maintaining microbial safety. This volume provides an up to date account of all the major drying technologies employed in the food industry and their underlying scientific principles and effects. Various equipment designs are classified and described. The impact of drying on food properties is covered, and the micro-structural changes caused by the process are examined, highlighting their usefulness in process analysis and food design. Key methods for assessing food properties of dried products are described, and pre-concentration and drying control strategies are reviewed. Thermal hazards and fire/explosion detection and prevention for dryers are discussed in a dedicated chapter. Where appropriate, sample calculations are included for engineers and technologists to follow. The book is directed at food scientists and technologists in industry and research, food engineers and drying equipment manufacturers.

First Published in 1995, this book offers a full guide into industrial drying for various materials. Carefully compiled and filled with a vast repertoire of notes, diagrams, and references this book serves as a useful reference for students of medicine and other practitioners in their respective fields.

Drying is an important unit operation used in the industry for processing and preservation of food products. Food industry always looks for cost effective and energy efficient drying techniques to commercially succeed in their ventures and to fulfill demand of high quality dried food products. Although a large volume of technical literature is available on drying of foods, it is still quite challenging for scientists and engineers to improve upon the existing drying systems and quality of the products. The book consists of 14 chapters detailing freeze drying, atmospheric freeze drying, swell drying, multi-flash drying, electro-hydrodynamic drying, pulse combustion drying, foam mat drying, ultrasound- assisted drying and fluidized bed drying. It also includes chapters which are commodity-specific such as mushroom drying, drying and roasting of cocoa and coffee beans. The degradation mechanism and kinetics of vitamin C degradation in fruits and vegetables, kinetics modeling of drying process for the recovery of bioactive compounds and energy calculation procedures for dryers is also covered which would be helpful to improve dryer operation and efficiency.

A guide to the major food drying techniques and equipment. It features technologies for meats, fruits, vegetables, and seafood. It covers microbial issues and safety. It includes designs for drying systems and manufacturing lines, and information on microbial safety, preservation, and packaging.

By far the most commonly encountered and energy-intensive unit operation in almost all industrial sectors, industrial drying continues to attract the interest of scientists, researchers, and engineers. The Handbook of Industrial Drying, Fourth Edition not only delivers a comprehensive treatment of the current state of the art, but also serves as a consultative reference for streamlining industrial drying operations. New to the Fourth Edition: Computational fluid dynamic simulation Solar, impingement, and pulse combustion drying Drying of fruits, vegetables, sugar, biomass, and coal Physicochemical aspects of sludge drying Life-cycle assessment of drying systems Covering commonly encountered dryers as well as innovative dryers with future potential, the Handbook of Industrial Drying, Fourth Edition not only details the latest developments in the field, but also explains how improvements in dryer design and operation can increase energy efficiency and cost-effectiveness.