Foodelphi.com Science of Food Engineering
Food Processing Machine and Equipment Cleaning and Sorting
Dr. Salih KARASU
Pretreatment proces
The raw materials represent a major cost factor. Hence, it is very important to procure the raw materials that comply with the specifications laid down by the manufacturer of the plant so as to minimize the defect levels
The selection of raw materials as well as selection of preparatory operations should be done in such a way so as to minimize the waste and to maximize the product yield.
Cleaning
All raw materials must be subjected to cleaning process before production. The main reason for the cleaning process;
To protect consumer health,
To increase the quality of raw materials and to ensure the good quality of the final products
Prevent food equipment from being damaged
Prevent product loss
All materils with exception of high quality raw material can be defined as foreign material
Impurities for food industry
impurities
Metals
Petroleum products and minerals
Plant origin
Origin of animal
Chemicals
Microorganims
Microbial metabolites
Exp.
Iron, copper, aluminum…
Soil, stone, motor oils, diesel
Leaf, straw, stalk, seed, …
Hair, bone, bug,
Fertilizer, pesticide,
Bacteria, mold, yeast
Microbial toxins, antibiotics,
Cleaning Methods
The selection of a cleaning method is determined by, the nature of the product to be cleaned, the types of contaminant to be removed and, the desired condition of the cleaned material.
There are basically two types of cleaning methods, which are generally used either singly or in combination- dry cleaning and wet cleaning.
Different principles are used to remove impurities in differentraw materials.
Fruits and vegetables are subjected to wet cleaning process. Brush, roller and spray systems are used.
The cereals and oily seed are cleaned with pneumatic systems, sieves and metal holders.
The lower dimension impurities are removed with special
systems(Ultraviole, X-ray, NMR, sonication)
Dry cleaning
Dry cleaning methods are used for products that are smaller, have greater mechanical strength and possess lower moisture content.
The main advantages of dry cleaning methods are that, these methods are generally inexpensive and involve cheaper equipment than wet cleaning methods, and produce a concentrated dry effluent which may be disposed of more cheaply, but it suffers from various disadvantages such as, it is prone to production of dust, which can be a source of product recontamination and in some cases, a fire and explosion hazard.
Dry cleaning systems
The main groups of equipment used for dry cleaning are:
Aspirators,
Magnetic separators,
Separators based on screening of foods
Screens
Screens remove contaminants that have sizes different from the product.
A screen in a frame is the simplest form used which has now been largely replaced by continuous types, such as centrifugal screens, vibrate, and the flat bed screens.
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