# Food Engineering:Food Science and Technology

## Why we need to study food?

Food changes as a result of changes. Such changes can be physical, chemical, enzymatic or microbiological. It is essential to understand the quantitative analysis of unit operations and therefore your ability to use or apply mathematics is essential. lets gradually move to food engineering review.

**Basics of Food Engineering**

The basic concept of units and their implications is highly significant for learning various aspects of food engineering. The following must understand deeply for the basic knowledge regarding food engineering:

- Concept of unit operation
- SI Units
- Common units and conversion factors
- Dimensional analysis
- Conservation of mass
- Conservation of energy

**Concept of unit operation**

In all the processing industries such as food biological or chemical. There exist similarities where feed is processed into final products. These processing steps could be chemical, physical or biological or in combination under usually separate and distinct steps called unit operations. Unit operations can be classified as follows:

**Fluid flow** : Deals with the principle that determines the flow or transportation of fluid from one point to another.

**Heat Transfer:** Deals with principles that govern accumulation and transfer of heat and energy.

**Evaporation:** Special case of heat transfer, which deals with the evaporation of a constituent from a solution.

**Drying:** Operation where volatile liquids, usually water, are removed from solid materials.

**Distillation:** Operation where components of a liquid mixture are separated by boiling based on the vapor pressure difference.

**Absorption:** Process in which a component is removed from a gas stream by liquid treatment.

**Membrane separation:** It works on the diffusion principle. It separates solute from a gas or liquid by a semi-permeable barrier to another liquid or gas by diffusion.

**Liquid-Liquid Extraction:** Process where a solute in a liquid solution is removed by contacting with another liquid solvent which is relatively immiscible with the solution.

**Adsorption:** Process was a component of a gas or a liquid stream is removed and absorbed by a solid adsorbent.

**Liquid solid leaching:** Process was a finely divided solid I treated with a liquid that dissolves out and removes a solute contained in the solid.

**Crystallization:** Removal of a solute such as salt from a solution by precipitating the solute from the solution.

**Mechanical-Physical Separation:** It separates gasses, liquids or solids by using chemical techniques or means such as size education, filtration or settling and are classified as a complete unit operation.

**SI System of Base units**

To analyze and quantify physical processes or unit operations. Understanding the units and dimensions of the quantities becomes essential. There are three basic unit systems employed in engineering and science.

Presently, the SI system has been adopted officially for exclusively using engineering and science.

**Derived Units of SI system**

These units have special names which are usually algebraic combinations of base units expressed using multiplication and division. For easiness derived units mostly assign as special names and character or symbols that often used to solve the remaining or needed derived units.

**Common units and conversion factors**

Converting of units is a methodical process which involves division and multiplication by a numerical factor. For instance, 12 feet 5 inches is converted to inches as follows.

**Dimensional Analysis**

Dimensional analysis is a tool to represent relevant data. It is a useful technique for experimental based engineering fields. Dimensional analysis is a way for simplifying a physical problem by appealing a dimension homogeneity to lessen the number of variables. In dimensional analysis, we are only concerned with the nature of the dimension that is its quality, not its quantity. The following dimensional are used for the dimensional analysis:

We can represent all the physical properties we are interested in with L, M and T. Sometime could be included. Dimensional analysis is particularly is used for:

- Presenting and interpreting experimental data
- Attacking problems to amenable to a direct theoretical solution
- Checking equations
- Establishing the relative importance of particular physical phenomena
- In help in understanding the physical modelling of the process

**Dimension homogeneity:**

Any equation describing a physical situation will only be true if both sides have the same dimension. That is, it should be dimensionally homogeneous. For example, the Bernoulli’s equation:

The SI unit for each term on the left-hand side should be consistent and equal,

The dimension of all the above-mentioned terms is equally. So, the units of the right-hand side are equals to the units of the left-hand side that makes the equation dimensionally correct. As we know that the content has always the dimension of . That is the units are consistent. The dimensional homogeneity is a useful tool for checking formula. For this reason, it is useful when analyzing a physical problem to retake algebraic symbols for as long as possible. Only substituting numbers right till the end. Dimensional analysis cannot determine numerical factors. For example, it cannot distinguish between,

**Dimensional homogeneity property can be useful for the following:**

- Checking units of equation
- Converting between two sets of units
- Defining dimensionless relationships

**Conservation of Mass**

The principle of conservation of mass states that mass can be neither be created nor be destroyed however its composition can be altered from one form to another. The conservation of mass principle is given by the following equation.

**Conservation of Energy**

By the first law of thermodynamics can be stated as “Energy can be neither created nor be destroyed but it can transfer from one form to another”. The conservation of energy principle is given by the following equation.

**In a nutshell**

Food Engineering is a significant component of the typical element for the undergraduate degree in food science or food technology. Food Engineering is an integral and significant ingredient to understand the theoretical aspect of food processing into practical implication. Physics, chemistry and mathematics are essential in gaining an understanding of the principle that governs most of the unit operations which are commonly found in the food industry.

To read my article on 3 types of food contamination you should know

and read how kitchen working persons contaminate food.