Plant hygiene

In some situations, if good plant hygiene is not maintained, fungal spores can also become established in and around the Fourdrinier wire. These can develop into large surface colonies which can become dislodged and transfer onto the paper sheet during formation. Again, this can lead to paper sheet failure. 

Good plant hygiene procedures are critical to maintaining an effective production, however due to the nature of the process, this will not be wholly effective and the use of biocides is critical to maintain a low microbiological population to prevent paper failure. The table below (Table 4) illustrates the types of biocides that are commonly encountered within the paper processing. 

It is said that cleanliness is next to godliness and manufacturing plants are no exception to this maxim. Many of the contamination problems that occur in manufactured products have their origins in poor plant hygiene, resulting in uncertain product, customer complaints and unnecessarily high biocide addition levels. 

The trend from heavy metal and phenolic based biocides, e.g. mercury and pentachlorophenol types, to more environmentally acceptable but less persistent organic types, requires more attention to plant hygiene (Figure 6, Briggs, 1980). 

Good plant hygiene is one of the key factors in avoiding problems. 

Dust generation can lead to a number of problems for food powders. These can be summarised as follows (i) health problems, in particular allergy problems (ii) contamination and plant hygiene issues due to dust settling and sticking onto equipment and (iii) fire/explosion hazards. As a result, improvement in dust measurement, prevention and control is a major issue when dealing with food powders. 

Short-life Creams. For short-life creams, the shelf life depends on a low-bacteriological-count milk with good plant hygiene. Heat treatment tends to be in the region of 75-90°C with 3-30 s hold, followed by cooling to below 10°C. Final cooling to below 5°C is normally carried out in aging tanks or in the retail container in the cold store. Shelf life can be up to 12 days (76). 

B. V. Smith, Plant Hygiene and Microbiology in the Production of Margarine, Internal Memorandum, Crown Wurster Sanger, Minneapolis, Minnesota, 1990. 

In addition to the supply of personal protective equipment and the maintenance of plant hygiene control systems, it is essential to ensure that ... 

Almost ubiquitously, ATP tests are employed to check plant hygiene. This includes both swab tests of vessels and pipework and liquid tests of CIP final rinse water. Typical sample locations and types are shown in Table 13.7. 

The implementation of a planned plant hygiene programme involving regular audits, assisted by external experts, if necessary, should be a priority. This can be assisted by the implementation of a plant hygiene checklist (Table 12) which can be included as part of in-house quality systems (Gillatt, 1993). 

Rigarlsford, J., 1987. Plant hygiene and disinfection. Notes from Preservation Towards 1990 and Beyond, Conference held at Ladbroke Hotel, Warwick, UK, 11/12 June. 

To fulfil these requirements, not only the selection of preservative type and concentration needs careful consideration during formulation development, but also the type and extent of potential microbial influences which might adversely effect the quality of the finished product quality. The microbial quality of raw materials is a particularly important factor, but the provision of comprehensive production instructions, covering the processing of preservatives and plant hygiene, from the receipt of raw materials to the dispatch of the end product is also vital. 

Plant hygiene (Production and storage hygiene measurements)... 

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