Simple Rules for Bottling Plants

1.       Segregation – The filling area should under a positive air pressure, to avoid inflow of contaminated air.  HEPA filters should be used to filter the air and these should be checked regularly to avoid blockage.  Either the filler should be treated in this way or the whole bottling plant should be under positive pressure if the filler is not enclosed.  Entry into the area must be limited to essential personnel wearing appropriate protective clothing.  Aseptic filling requires very high standards of hygiene and preferably should be run automatically and remotely from human participation.  When this is not possible, the operator should be specially trained to work in an aseptic environment.

2.       Process lines – The distance between the filler and capper should be as short as possible and likewise the distance between the blow moulding unit and the filler, although in the latter case this is not always possible.  Companies filling glass bottles must have a “glass breakage policy” to detail actions taken when glass breakage occurs.  If conveyor lubricants are used, these must be of the H1 grade (approved for indirect food contact).

Hygienic Design and Location of Bottling plants

1.       Site – avoid locations that could create problems in the future, e.g., nearby chemical works, rivers that may flood, farming environments.  The latter are a significant risk if animals are close by.  Transport of contaminants on footwear into the plant can be a big issue and there is a higher risk of pest infestation, both from flying insects and rodents.  Many bottling plants are located on farmland where the spring source originates.

2.       Building – the building must be fit for purpose and approved for food production.  It is unwise to use converted barns and the building should be purpose built.  A high-risk area should be defined within the building where product in open bottles is present.  The bottling plant should be sealed off from the external environment and no external doors should open directly to the outside.  Windows should be non-opening preferably or, at least , fitted with insect grills.  Glass should be strengthened and shatter-proof, this applies to windows, doors and lighting.  Drains should be fitted with traps and kept clear of blockage.  Toilets and canteen areas should not open directly into the plant area.  A hygiene and cleaning schedule needs to be created for the whole building based on the risk analysis highlighted by the HACCP programme.  External areas should be policed for excessive rubbish accumulation and encroachment of vegetation.

Sanitising Sealed Mains-Fed Water Coolers

Sanitising sealed mains-fed water coolers can be difficult but not impossible.  The main issue is how to get the descaling and disinfectant liquids into the unit. Typical units are the direct chill or spiral chill type.  Frequency for sanitising and filter changes is every 6 months.

The filter housing can be disconnected from the microbore tubing and a small device known as a venturi doser put in its place.  The doser is filled with the recommended amount of descaler and the hot tap actuated.  This will draw descaling acid solution into the tank.  After descaling, flush with at least 4 litres of water and test with pH paper until neutral.

The spiral chill pathways can be descaled and then disinfected using the same technique with respectively phosphoric acid (for example) and hydrogen peroxide.  The chemical is drawn from the doser by actuating the chill tap.  When the chemical begins to run from the tap (you can check this with pH paper or peroxide test strips), turn the tap off and wait for ten minutes.  Then flush with water until the test strips are clear.

This is not a detailed procedure and coolers vary considerably in design, however it will serve as a guideline.  Always check with your cooler supplier if in doubt.

Descaling and Disinfecting Water Coolers

The hot tank of coolers can be descaled using an acid such as phosphoric or citric. Sometimes other internal  parts of coolers need to be descaled and disinfected.  Scale build up in reservoirs, for example, is usually not severe but can lead to microbiological problems if left.  Attachment of micro-organisms and ultimately formation of a biofilm can rapidly cause deep-seated contamination which is not always easy to remove.

It is common practice to use a descaler, accompanied by mechanical action such as brushing, followed by a disinfectant such as hydrogen peroxide.  This will remove the scale and destroy the biofilm.  In some practices it is considered that one application of acid is sufficient to descale and destroy biofilm.  This is not always the case and is very dependent on the strength of acid used.  Very strong acids will do the job but these are usually applied diluted.

Diluted acids will remove scale more slowly and much of the acid is used up in this process.  In this case biofilm will not be removed.  If you want to use acid alone, then either use very strong acid (not recommended from a safety point of view) or use the acid in two steps, one to descale and the other to kill bacteria.

An alternative is to use an acid containing a disinfectant component which can then act as a sanitiser while removing scale.  These are available on the market.  However, the preferred method is to descale and then disinfect, in two separate steps.

Rapid Testing of Water Samples in the Bottling Plant

Following on from the ATP article in a recent blog, this section describes the procedure for rapid microbial testing of water samples.

Because water samples contain very few bacteria, an enrichment technique is employed. This involves taking a sample aseptically, and expelling it via a syringe through a special filter.

After waiting for 30 minutes to allow the microorganisms to recover from the stress of filtration, the filter housing is opened and the filter swabbed, using the special swab used in the ATP meter.

The swab is put back into the swab tube and activated using the snap and squeeze action. The swab is placed in the ATP meter and the measurement started. Results are recorded from the display.

Simple Microbiological Testing in the Bottling Plant

A new type of dipslide has recently appeared on the market which is double sided and able to detect 4 different groups of organisms:
1. Nutrient agar on one side to detect total counts.
2. Chromomeric coliform, E. Coli and pseudomonas aeruginosa on the other side.

It is a very versatile slide that can be used to dip into liquid samples or used as a contact plate on solid surfaces. The nutrient agar reacts with enzyme to produce a colour change which is specific to the bacteria type, allowing easy enumeration.

When sampling fluids, the sample is taken by immersing both sides of the paddle into the fluid to be tested. Excess sample should be gently shaken from the paddle before replacing in the container.

Surfaces can be sampled by allowing direct contact between the agar surface and the test material. The paddle is flexible and can be bent at the upper end to allow both surfaces to come into intimate contact.

Bacterial recovery rate is about 50% so that sweeping an area approximately twice that of the paddle will give a more accurate result. Afterwards incubate at 30/35 deg C for 24-48 hours, when full enumeration should be complete.

Apart from an indicator of aerobic bacteria (TVC), as shown in the picture above, the reverse side will give an indication of coliforms and Pseudomonas according to the following colour scheme: blue/purple or blue/green colonies = E.coli; pink/magenta colonies = other coliforms; buff colonies = Pseudomonas.

Recycling Plastics from the Bottling Plant

I previously attended a seminar run by the Food and Drink Association in the South West of the UK, entitled “Make Money, Not Waste”. This gave an up-to-date picture of latest developments in recycling and sustainability in general. My interest and perspectives were naturally focused on bottled water applications.

The main waste issues for bottlers are caps, 19L bottles and chemical drums, particularly the 25L size. Unfortunately all three items are made of different kinds of plastic which sometimes deters recyclers from collecting smaller quantities. If you are fortunate enough to be near a recycling site there may be an opportunity to drop off unwanted drums during the course of a delivery round by your drivers. However, this is not always convenient.

The organisation WRAP (Waste and Recycling Action Programme) currently has a study underway to collect plastics from smaller companies and deliver them to recycling points. This is useful for those companies who find it difficult to persuade recyclers to collect smaller quantities.