PL Kaul discusses the importance of automation systems in the modern food processing industry To keep pace with technological developments and maintain high quality standards, automation has become a prime necessity for the food processing industry, especially in the Indian context. The application of sophisticated automation systems in food processing is critical for two primary requirements. First, the scale of new units in the developed countries is too large for operations to be synchronised with just manual commands or semi-automatic process control systems. Secondly, the quality norms for food products intended for human consumption are getting more stringent, leaving virtually no scope for error.
 The application of modern process control automation systems based on technologies such as microelectronics or biosensor-based instrumentation has already become a reality. These technologies, interfaced with a centralised Programmable Logic Controller (PLC), are currently used to monitor, control, record and communicate the data for precise control of process parameters on a real-time basis.Thus, the application of sophisticated automation systems is becoming more relevant for the food processing industry because it is the area of manufacturing where quality is the most inconsistent attribute. The industry therefore needs precision monitoring and quality maintenance from the cultivation, harvesting and transportation stages to the processing, distribution and the development of the finished product. A few industry examples are discussed below to substantiate the role of automation in the food processing industry. Packing tomato paste in Italy
A 200-tonne per hour (TPH) plant for processing and packing super-high-viscosity tomato paste built by M/s Rossi Impianti in Italy was operated by a single supervisor and six operators. The entire operations were monitored from one centralised control room, equipped with computer and a mimic panel that displayed end-to-end processing activities along with all the in-process data-flow-rate, concentration, temperature, pressure, pH, rheological properties and the technical performance of the processing and conveying equipment. With the system, it became possible for the company to monitor and control productivity and quality at each process step without the application of more sophisticated automation. Overseeing operations in Germany A packaging line built by Jagenberg AG, Germany for packing tomato paste and beverages in disposable packs, had a capacity of 72,000 packs per hour of 500 g each. Due to its high-speed operation, a stroboscope with a microprocessor backup was used to visualise the quality parameters of the packs with regard to formation and printing of the packs. This was followed by the quality check for processes such as filling, sealing and conveying, till the palletisation and shrink-wrapping stages. The system enabled quality control for operations which were otherwise not perceptible to the naked eye. Processing wheat in Finland A plant built by RAISIO ENGG in Finland for processing around 100 TPH of wheat into gluten and starch-A in solid form, starch-B and dried grains with soluble (DDGS) was a huge setup with layout distributed on four floors. The entire unit in production was managed just by three personnel in a shift. One employee, confined to the control room, monitored the entire process plant in operation from the mimic panel and adjusted the process parameters simply by turning the knobs in front of him. The operator was able to manoeuvre the close-circuit television (CCTV) to watch the performance of individual equipment from the control room itself.  The second and the third operators, responsible for the quality control, periodically took samples at every stage of production for analysis. The data obtained was immediately transmitted to the centralised PLC to incorporate the adjustments in the operations if necessary. Making bread in India A food processing unit currently under development in Mariental, India, includes a fully automated line for production and packaging of Indian flat breads, with an installed capacity of about 54,000 units per hour per line. The state-of-the-art packaging line is incorporated with four basic systems which are operated automatically by highly efficient, reliable and user-friendly software. These systems include the Inspection and Rejection System, which individually analyses the quality parameters of the bread for toast marks, grease marks, rot marks, transparency, diameter, roundness, etc. Based on the analysis, it automatically sends the acceptable pieces to a green box and the rejected ones to a red box. The All Inverter Actuated Counter Stacker system automatically stacks the desired number of pieces as initially programmed and the count is recorded in the computer and displayed continuously on the screen. The remaining system components include the Stack Accumulator and Transfer System, and the Flat Bread Bagger and Sealer System. The inbuilt PLC-based microprocessor synchronises the continuous operation of the interlocked mechanical, pneumatic, hydraulic and the electronic components of the integrated line for an absolutely flawless production of the quality breads in such a large quantity. Automation solutions for various needs A number of automation solutions are available to cater to the diverse needs of various food processing sectors. Ensuring shelf-life A number of units producing ready-to eat food products in sealed retortable pouch packs, mostly at small-scale level, have been finding it rather difficult to sustain the quality of the product in the absence of suitable automation able to monitor and control the process parameters as desired. The stability and the shelf life being a direct function of the degree of sterilisation, measuring this for products lying sealed inside the pouch packs is rather difficult. The finished product is therefore cleared for sale only after keeping it under observation for a period of 21 days for the appearance of any pathological activity inside the pouch. However, with the availability of Ellab A/S, the Process Validation and Monitoring System supplied by a Danish company, the in-process product quality defined by the Cook Value and Food Sterilisation Value is monitored and recorded continuously on the computer. The clearance of the product for consumption has become instant, much to the relief of the small-scale entrepreneurs whose economic viability has considerably improved because the products are available for sale immediately after production. Detecting deficiencies, identifying threats Electronic sorting machines can be used for the removal of undesired particles present in grains or for colour sorting of apples or tomatoes. Automatic metal detectors used for detection and removal of metallic particles present in the finished products at incredible speeds are other examples of some fantastic applications of automation in food processing industry to ensure global compliance on quality. Automation tools using miniaturised microprocessors now find formidable application in small-scale operations as well. The use of biosensors for rapid, sensitive and specific detection of pathogens in food products before they are cleared for distribution substantially mitigates the threat of any health hazards. The speed at which the modern food processing and distribution systems operate, necessitate automation for testing and monitoring that can detect even minute pathogenic threats. In this regard, biosensors have already found diverse applications for stringent quality control procedures in the food processing industry, such as the development of multi-pathogen detection processes suitable for ground meats, etc. The rise of biosensors In the near future, biosensors could facilitate the development of procedures for simultaneous detection of pathogenic bacteria and their toxins through time-resolved fluorescenceI; the bio-luminescence approach for the detection of spores and viable pathogens, and simple visual detection methods using enzymatically generated silver stains. Biosensors also develop multiplexed immunoassays for food-borne pathogens in micro-array formats. We could soon see biosensors in conjunction with microelectronics facilitating the analytical revolution and resolving the remaining problems that hinder the exploitation of the biological molecules and their analogues.  Rapid test kits based on gene probe technology are also available. These can detect pathogens like Escherichia Coli, salmonella, Listeria Monocytogens and staphylococcus easily with accuracy and reliability. It can detect infections in basic foods and beverages in a matter of hours rather than days as in case of conventional methods of testing. Also available, are kits for the on-site tests for detection of food allergens and mycotoxins. These kits represent a break-through in instrumentation technology and are a boon to the food processing units. Such equipment can even be inter-linked through the satellite communication with the unit for instant transmission of data regarding the source of the raw material and its quality aspects. This will take care of the statutory provisions on traceability and the tractability, conforming to global CODEX norms as prescribed under World Trade Organisation guidelines. The need of the hour A food processing unit cannot be a success if it is devoid of backward and forward linkages. The backward linkage implies its close interaction with the farmers responsible for growing quality raw materials that yield the finished product compatible with the global standards. Automation must be addressed from the farm level itself. Testing equipment for all kinds of farm produce should be such that it is able to display the analytical test data instantly, but should be simple, so that even a farmer is able to make use of it. As the level of competence in the global food processing industry continues to increase, it has become essential for the Indian food processing industry to adopt automation technologies. Taking lessons from their global counterparts, the Indian food processing industry should implement cost-effective multitasking automation systems to achieve global competence. The author is MD, Mariental India Pvt Ltd |
