nach oben

2024 | Buch

Kapitel lesen Erstes Kapitel lesen

Food Engineering Principles and Practices

A One-Semester Course

verfasst von: Syed S. H. Rizvi

Verlag: Springer International Publishing

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

Einloggen, um Zugang zu erhalten

Über dieses Buch

This textbook is designed for a one-semester course on Food Engineering, and it offers a concise, in-depth and integrated introduction to the fundamental engineering and physicochemical principles and practices of utility in food processing and manufacturing operations. The textbook includes topics mandated by the Institute of Food Technologists for accreditation of Food Science curricula and helps prepare the students better for taking advance courses related to unit operations in food manufacturing. It is also relevant for Food Process Engineering courses, containing materials that most instructors can cover in three semester hours of instruction. In the first three chapters, readers will find an overview of the basic knowledge of physics and chemistry and an introduction to the engineering language needed to eliminate confusion going forward. In the following chapters, the author covers the main concepts of food thermodynamics, heat transfer–radiation in foodmaterials, mass transfer and fluid dynamics in food, along with real-life examples and exercises to help students relate better to the topics. The author also gives a brief introduction to the main mathematical and analytical concepts required in food engineering.

This textbook equips readers to understand a diversity of food engineering related topics and each chapter is enriched with practical examples and Check Your Understanding sections, as well as several problems. The textbook is aimed at undergraduate food science students in their first required introductory food engineering course, but practitioners involved in designing, optimizing, and managing the processing of food products will also find it a useful account.

Inhaltsverzeichnis

Frontmatter

1. Basic Concepts and Material Properties

Abstract

This chapter provides a review of important concepts that are needed to formulate, solve, and interpret food systems and manufacturing processes. They also provide a good foundation for learning more advanced scientific and engineering concepts and principles. Mastering these fundamental principles and their applications is essential for long-term successes both in and out of the classroom.

Syed S. H. Rizvi

2. Systems, Processes, and Fluid Phase Equilibria

Abstract

The job of the food engineer involves the design and/or operation of equipment needed to process food. Many different types of equipment are used to perform such processes as pasteurization, sterilization, evaporation, drying, freezing, and blending. If an engineer attempted to approach each piece of equipment as a totally new problem, the task would be overwhelming. Instead, he or she learns relatively few basic principles that are common to such equipment and applies them to solve the problems of design and operation.

Syed S. H. Rizvi

3. Thermodynamics: Basic Concepts

Abstract

Thermodynamics studies the changes associated with the exchange of energy between a system and its surroundings. It establishes the conditions that determine the equilibrium states of systems. It is based on the following three laws, which describe the essential role of energy and predict and explain the direction of change in matter and processes with subtle and complex implications.

Syed S. H. Rizvi

4. Mass and Energy Balances

Abstract

One of the most important skills you can develop in Food Engineering is that of performing mass and energy balances. They are used for the design, operation, control, and analysis of processing operations as well as in product development and waste reduction. Mass and energy balances are based on the laws of the conservation of matter and energy, which state that neither matter nor energy can be created or destroyed. This being so, you should, with careful measurement, be able to account for all the matter and energy involved in a process. Mass and energy balances provide a framework for accounting of material and energy flows in and out of a process of interest. The same thing is true of your bank account. You should be able to account for every penny. When you balance your checkbook, you list the following information:

Syed S. H. Rizvi

5. Fluid Mechanics: Basic Concepts

Abstract

The various unit operations used in the processing and manufacturing of materials have been grouped, based on the commonality of some underlying principles, together into three fundamental, molecular-level transfer (or transport) processes: mass transport, heat transport, and momentum transport. As we will see later, there exists mathematical analogy among these three processes, and although their physical mechanisms are totally different, in the elementary sense they can be described by the same general equation. Fluid mechanics addresses the study of momentum transport in a fluid and much of food engineering is concerned with the handling of fluids. Many food products are fluids or are in a fluid stage at some point in their processing. In addition, fluids such as water, steam, refrigerants, and air are used to heat, cool, and otherwise process foods. This chapter will introduce the engineering principles of fluid mechanics that underlie the study of the forces on fluids and their utility in the use and handling of fluids. Fluid mechanics includes both fluid statics and fluid dynamics (Fig. 5.1). It is based on the principle of conservation of mass, energy, and momentum (following Newton’s second and third laws). Additionally, fluids are assumed to represent a continuum rather than discrete parts, and the fact that a fluid is composed of discrete molecules is ignored.

Syed S. H. Rizvi

6. Fluid Mechanics: Applications

Abstract

In this chapter, we will focus on some selected applications of fluid mechanics. Food processing and manufacturing operations involve handling various types of fluids, including liquids, gases, steam, and fluidized materials. They follow many of the same laws and exhibit similar resistance to flow and are thus grouped together for analysis and process design purposes. Based on their unifying theory, engineering operations are often categorized into unit operations such as heating, cooling, drying, sheeting, and homogenization. The fluid flow properties and design of the handling and transport system in each unit operation and how fluids are moved from one operation to another control the resulting quality, safety, and consistency of the final products. Thus, a good understanding of the design considerations is needed. Although specific requirements depend on the product characteristics and the processes involved, elimination of dead spots where microorganisms could grow, ease of clean-in-place (CIP) and overall operational efficiency apply to all food handling systems. In Chap. 5, we discussed the basics of the flow of fluids. In this chapter, we will learn how those principles are utilized in selecting and setting up equipment and pipeline networks that are used to process and transport fluids such as liquid foods and related materials.

Syed S. H. Rizvi

7. Heat Transfer: Steady-State Conduction

Abstract

Heat transfer involves the flow of thermal energy between objects due to temperature differences. It is an integral part of food processing and preservation techniques. Heating to make foods easier to digest and safe to eat has been practiced since time immemorial. It also helps extend their shelf life and makes them taste better. To achieve this, food processes require that heat be transferred into and out of the food. Some examples include:

Syed S. H. Rizvi

8. Heat Transfer: Steady-State Convection

Abstract

In Chap. 7, we introduced the idea of heat transport, concentrating on steady-state conduction through various geometric forms. In this chapter, we will look at heat transfer by convection and combinations of convection and conduction.

Syed S. H. Rizvi

9. Heat Transfer: Unsteady State

Abstract

We have shown how heat travels through materials. However, the movement of heat does not necessarily imply a movement of temperature changes. In fact, in a steady state, heat flows with no temperature change with time at a particular point in a process. In this section, we will examine the unsteady state or transient heat transfer. Under unsteady-state conditions, the temperature within the material varies with time, and we will see what factors affect the migration of temperature changes through an object. All the heating transfer processes are initially under unsteady-state conditions.

Syed S. H. Rizvi

10. Heat Transfer: Radiation, Dielectric and Ohmic

Abstract

As we learned in the previous chapters, in conventional thermal processes, heat is generated outside of the object to be heated and is then transferred to the material by conduction, convection, or a combination of the two mechanisms. Radiation is the third mode of energy transfer that occurs through electromagnetic waves without involving a medium. Light and heat are examples of types of radiations. In process engineering applications, all three modes of heat transfer are generally involved. Thermal processing technologies using specific radiation waves and Ohmic heating, where thermal energy is generated and absorbed directly by food materials, are finding increasingly new applications for targeted energy delivery to improve food product quality and achieve higher energy efficiencies.

Syed S. H. Rizvi

11. Mass Transfer: Basic Concepts

Abstract

Mass transfer refers to the net movement of a component (species) in an inhomogeneous system from one location to another in the same or different phase with the aim of making it homogenous and bringing the system closer to equilibrium. Chemical potential difference is the main driving force for mass transfer and depends on various factors like concentration, temperature, pressure, and molecular interactions. Mass transfer occurs by molecular diffusion and bulk flow and does not include movements of materials such as pneumatic conveying of powders, carrying of fruit boxes, or pumping of liquids through pipes. Mass transfer is an important molecular phenomenon that occurs extensively in gases, liquids, and solids in the natural environment as well as in processing and manufacturing industries. It is the basis for numerous biological and chemical processes of direct interest to us, ranging from cooking, digestion, and absorption of foods to separation and purification of products from their matrices.

Syed S. H. Rizvi

12. Refrigeration Systems

Abstract

Your kitchen refrigerator (or any other) cools food by removing heat from its interior and dumping it into the kitchen. This means it moves heat from a cold place to a warm place. However, the second law of thermodynamics states that it is impossible for heat to flow from a cold body to a warm body, while the reverse will always happen, and heat (q) will spontaneously flow from a hot reservoir to a cold reservoir, as shown in Fig. 12.1. For heat (q_c) to flow from a cold area to a warmer area, work (w) must be performed such that, according to the first law of thermodynamics, the total heat (q_h) transferred is:

Syed S. H. Rizvi

13. Psychrometrics

Abstract

Psychrometrics is concerned with the measurement of moisture in gases, particularly in air. Psychrometrics can be used to answer such questions as:

Syed S. H. Rizvi

Backmatter

Titel: Food Engineering Principles and Practices
verfasst von: Syed S. H. Rizvi
Verlag: Springer International Publishing
Electronic ISBN: 978-3-031-34123-6
Print ISBN: 978-3-031-34122-9
DOI: https://doi.org/10.1007/978-3-031-34123-6

Premium Partner

Marktübersichten

Die im Laufe eines Jahres in der „adhäsion“ veröffentlichten Marktübersichten helfen Anwendern verschiedenster Branchen, sich einen gezielten Überblick über Lieferantenangebote zu verschaffen.

Zur Marktübersicht