Any loose food material should be removed before the application of cleaning solutions. This may be accomplished by flushing the equipment surface with cold or warm water under moderate pressure. Very hot water or steam should not be used because it may make cleaning more difficult.
There are many methods of subjecting the surface of the equipment to cleaning compounds and solutions. Effectiveness and the economy of the method generally dictate its use. The components of commercial cleaning compounds modify the nature of water so that it may efficiently penetrate, dislodge, and carry away surface contamination (soil). Although energy is put into the system (generally, in the form of heat and applied force), cleaning compounds decrease the external energy requirements by increasing the internal potential energy of the water.
In this respect, cleaning can be done in the following four steps:
- Bringing the cleaning solution into intimate contact with the soil to be removed by means of good wetting and penetrating properties.
- Displacement of the solids and liquid soils from the surface to be cleaned by saponifying the fat, peptizing the proteins, and dissolving the minerals.
- Dispersion of the soil in the solution by dispersion, deflocculation or emulsification.
- Preventing re-deposition of the dispersed soil back onto the clean surface by providing good rinsing properties.
Application of Cleaning Methods
The food ingredients manufacturing sector in India, an export oriented industry, is fast growing and includes dehydrated onion, garlic & vegetable extracts, flavours, additives, emulsifiers, ready made soup mixes, and a range of other similar products.
The dehydration system consists of onion/vegetable washing, peeling, flaxing and an efficient multi deck continuous imperial dryer. Since the water removal ranges for about 50 to 90% of the raw material, 100kg of fresh onion flakes would be reduced to 12kg after dehydration.
Once dehydrated, flakes are directly packed or chopped, kibbled, minced or granulated to required size. The lower quality flakes are made into fine powder. A multi-deck Vibro sifter is utilised to segregate the granules into various size grades.
Hygiene in manufacturing process
The onion lots are graded as per the size & quality and then peeled. The top layer of the raw onion bulbs is removed. The peeled onions are washed by agitation and are then sliced in the slicing machine. Strict hygiene is maintained while washing.
Sliced onions are fed in the imperial dryer for dehydration without effecting the taste and pungency. Dehydrated onions are shifted to clean air conditioned rooms and fed into the kibbling machine to obtain the kibbled form. The skins are then removed from the kibbled with blowers.
Further impurities are removed through imported colour auto sortex machine. The product is passed through high power magnetic sticks and metal detectors to remove all metal impurities.
As per the buyer specification, kibbled undergoes milling and sizing process. The produce is separated into chopped, minced and granules vide gyratory screens. The finished product are weighed and sealed in moisture proof food grade poly bags. The bags are packed in corrugated boxes or paper bags.
“We use Dodia machine, that comes with a boiler for water, which helps circulate the radiator and generates heat and dehydrate onion,” he informed. The equipment are taken up for cleaning every 10 days. The 12-hour cleaning process consists of first cleaning using air and then water with the help of 15 labourers. Cleaning solutions are sprayed on equipment surfaces using either fixed or portable spraying units with hot water or steam.
Talking about the cleaning of onions in the dehydration unit, Milap from Amul Dehydration, Junagadh said, “The roots of the onions are removed manually and then washed with the help of rotators, which is connected through a Feeding belt and Shaft, in the unit. The onion is washed in a container located at a height of five feet and then dropped into the processor. Recovery of raw material is negligible as the chances of spoilage, in this case, are one in 500 onions.” Two kilogrammes of wafers can be processed from 20kg of onions.
Chemicals are not used during the process, as it is mostly exported and they are used to maintain whiteness. The capacity of the plant is six metric tonnes.
According to Hasmukhbhai Senta, Jalaram Food, Junagadh, “Onion is generally washed with plain water and washing chemicals in a very small quantity. The workflow process involves washing, peeling, cutting, spinning, dehydrating, kibbling and finally packing. “We use chemicals for floor cleaning only.”
In a recent FDA survey, less than 50% of candy, ice cream and baked-goods manufacturers are employing procedures to control cross-contamination of foods with allergens. The Department of Agriculture recommends that food companies adopt SSOPs and proper cleaning practices with careful vacuuming.
Designed to meet the general plant cleaning and maintenance needs of food manufacturers, vacuum machine is powered by two independent bypass motors, which can fit both 30 and 55-gal. drums, allowing users to recycle drums that are abundant in nearly every production plant. An optional float chamber and washable cartridge filter allows the vacuums to pick up both wet and dry materials. The machine can also be fitted with an upstream HEPA filter for pick-up of hazardous materials down to and including 0.3 microns in size.
Informed Bhupatbhai Koradiya, World Dehydration Foods and Spices, “The machine used by us in vacuum cleaning is called Air compressor, which costs rupees four lakhs. It blows fast air into the machine of dimensions 20ft x 50ft to extract the waste. Shutters are opened during the process of cleaning the machine.”
Ozone technology has held promise for food processors for decades. Today, it is emerging as a versatile technology that can be used in a wide variety of applications that include disinfecting water supplies, wastewater treatment and a variety of plant cleaning and sanitation functions.
र85,000. It is an automated machine and there are hoses attached to it, which clean the entire machine in five hours time.
Hydraulic cleaning systems are frequently utilised for cleaning the exterior parts of equipment, floors and some building surfaces. High pressure cleaning is based on atomisation of the cleaning compound through a high pressure spray nozzle. Steam injection systems and pressure-fed tanks generally operate with nozzle pressures between 60-175psi, whereas air and motor-driven high pressure pumps may develop nozzle pressures from 300-1200psi. Cleaning effectiveness is dependent largely upon the force of the cleaning solution against the surface, which is controlled by the nozzle design.
“Some dehydration units use Hypo chemical with water to clean onion for ensuring its whiteness. We use two litres of hypo chemical daily, says one of the manufacturer.”
The primary reason for the application of effective sanitizing procedures is to reduce those disease organisms which may be present on equipment or utensils after cleaning to a safe level and thus preventing the transfer of such organisms to the ultimate consumer. In addition, sanitizing procedures may prevent spoilage of foods. The existence of any microbe in a food environment must strictly be controlled. The so-called harmless microbe under the proper conditions can become a nuisance.
Manubhai Ram from Rajdhani Dehydration, Bhavnagar said, “Three tanks are used for washing and cutting with drier (which has radiators) to dehydrate into three grading material – powder material, main granules and chops. We source Hypo chemicals from Rajkot – to kill germs and to make it white. There are different chemicals for cooling towers and radiators.
One relatively recent approach is the ultrasonic cleaning tanks in which equipment is immersed in a cleaning solution and cleaned by the scrubbing action of microscopic bubbles caused by high frequency vibrations (20,000-40,000 cycles per second).
Current Scenario
As of today, the imported machine costing र35 to 40 lakh, has cleaning in place systems, based on the vacuum cleaning technology. It is a fully automatic machine of nearly seven ton capacity.
The primary reason for the application of effective sanitizing procedures is to reduce those disease organisms which may be present on equipment or utensils after cleaning to a safe level and thus preventing the transfer of such organisms to the ultimate consumer.
Clean-in-Place systems have an automated cleaning system generally used in conjunction with permanent welded pipeline systems. In CIP cleaning, fluid turbulence in pipelines is considered to be the major source of energy required for soil removal.
Clean-out-of-place (COP) system ensures that many small parts can be washed most effectively in a recirculating parts washer (sometimes called COP-cleaned out of place). These units are similar to sanitary pipe washers in that a sanitary tank is generally utilized in combination with a recirculating pump and distribution headers that provide considerable agitation of the cleaning solution. In some cases, the washer for parts may also serve as the recirculating unit for CIP cleaning operations.
Other Traditional Cleaning Methods
Soaking – Small equipment or fittings or valves may be immersed in cleaning solutions in a sink while larger vessels such as vats and tanks may be partially filled with a pre-dissolved cleaning solution. The cleaning solution should be hot 50OC (125OF) and the equipment permitted to soak for 15-30 minutes before manual or mechanical scrubbing.
Foaming – This method utilizes a concentrated blend of surfactants developed to be added to highly concentrated solutions of either alkaline or acid cleaners. It will produce stable, copious foam when applied with a foam generator. The foam clings to the surface to be cleaned, increases contact time of the liquid with the soil and prevents rapid drying and runoff of the liquid cleaner, thereby improving cleaning.
Gelling – This method utilizes a concentrated powdered gelling agent which is dissolved in hot water to form a viscous gel. The desired cleaning product is dissolved in the hot gel and the resulting gelled acid or alkaline detergent is sprayed on the surface to be cleaned. The gelled cleaner will hold a thin film on the surface for 30 minutes or longer to attack the soil. Soil and gel are removed with a pressure warm water rinse.