Manufacturing process
Ingredients
Ingredients
are chosen for their quality, consistency, and nutritional value. Every
ingredient is tested for all three of these attributes before being accepted
into the factory. Ingredients are stored in cool, dry conditions until
required. As an additional safeguard, many of the ingredient producers are
audited, to ensure that their manufacturing facilities and procedures are
suitable. Wherever possible, ingredients are purchased from the UK to support
the British economy and to ensure optimal freshness.
Weighing and mixing
Every
recipe is stored within a central computer system, and ingredients are weighed
on a range of scales, and then sent to a large mixing chamber, where they are
gently combined for 3 minutes. To minimise any variation, the recipes remain
fixed and the scales are tested routinely to ensure their accuracy. The mixture
is then passed over powerful magnets to ensure that it is free from any metal
contamination, and is sent on to the next stage.
Grinding
The next
stage is to grind all of the ingredients, which have a variety of sizes, in the
equivalent of a huge mortar and pestle. This produces a fine powder (grist),
with a similar consistency to baking flour. The blend is then mixed once again
and the more delicate ingredients, such as vitamins and trace minerals, are
added. We then have a homogenous and fine mixture of up to 50 ingredients,
which is sent on to be cooked. Super premium pet foods
such Arden Grange provide optimal, rather than minimal, levels of all
of the nutrients required for the species/age/lifestyle that the product is
intended for, and includes supplementary ingredients that have a positive
impact on health. Attention is paid to both the proportions and to the
diversity of sources of the nutrients.
Pre-conditioning
The first
stage of cooking involves conditioning the mixture. Steam and water
are added to the grist in a large chamber which contains rotating paddles. Much
like dough, the mixture is kneaded until most of the starch molecules are plump
and fully hydrated. This process also mixes the grist once again, and pre-cooks
the food to approximately 45% of its total 'cook'. Pre-conditioning lasts for
around 3 minutes, after which time the grist moves on to the final cooking
stage.
Extrusion cooking
The final
part of the 'cook' only lasts for 30 seconds, but provides for over half of the
total cooking process. The grist is passed through a long chamber containing a
rotating screw, which forces it to the end, and out through small, shaped
apertures. The pressure within this chamber can reach over 600 psi, and this
causes the plump starch molecules to burst and form a pliable mixture with the
other ingredients. As this mixture emerges from the end of the chamber, the
dramatic drop in pressure causes the food to expand to form a honeycomb-like
structure. A blade then cuts the food into chunks as it emerges, and these
light, soft kibbles are tested for their shape, colour, size, and
density, before being sent off to the next stage.
Drying
The kibbles
emerging from the extrusion cooker contain over 25% water, and since they do
not contain any artificial preservatives, they would soon become mouldy and
spoil. Therefore, the drier aims to remove around two-thirds of this water by
gently blowing hot air around the kibbles, as they pass through the chamber. This takes
approximately 20 minutes, and kibbles are continually tested for their moisture
content as they emerge from the drier, to ensure that they are satisfactory.
These crunchy kibbles are then ready for the next stage.
Coating
As we know
with many human foods and snacks, much of the flavour is in the coating. Too
much can be overpowering and off-putting, but too little can cause us to lose
interest. The same is true for dogs and cats. Therefore, the kibbles are coated
accurately and uniformly with a combination of oils and natural flavours which,
since the kibbles are coated whilst still hot, permeate throughout the food.
There is no added sugar or salt, which are often used as palatability
enhancers.
Cooling and packing
As we would
leave baked bread on a wire rack to cool, the same is true of the kibbles. If packed whilst still warm,
the kibbles would soon become soft and prone to mould. Therefore, the final
stage is to hold the food in a large chamber through which cold air is passed.
At this point, samples are also taken from all batches produced, which are
analysed for a variety of parameters including: nutrient content (e.g. protein,
oil, fibre, etc), bacterial loading (e.g. salmonella, campylobacter, etc), and
organoleptic features (e.g. smell, colour, size, etc). The samples are stored
for 2 years for future reference. Once
the kibbles have cooled to room temperature, and the batch has passed quality
assurance, the food is ready to be packed and sent off to the customer.
Arden Grange
pet foods are manufactured in the UK, and are formulated and labelled in
accordance with FEDIAF (the European Pet Food Industry Federation). Much like
baking a perfect loaf of bread, the quality of the final product depends upon
the quality of the ingredients, the accuracy of weighing and timing, and the
performance of the equipment.