Kev Tabb, assisted by Scott Barry, outlined the history of Marel, the company that they represented. Its origins could be traced back to a research project at the University of Iceland into weighing fish at sea, leading to the formation of the company in 1983.
Since those days the company has expanded to becoming an international supplier of ‘protein processing’ equipment, i.e. fish, poultry and meat.
The company continues to be research led and endeavours to produce machinery that will improve yield, throughput, consistency, quality and shelf life of the product.
While these factors applied to all of the company’s activities this talk was essentially confined to the processing of farmed salmon.
It was explained how important this industry was world-wide and particularly to Scotland where it is a £500M p.a. business employing some 8,000 people. The equipment that Marel supply this industry can potentially convert raw salmon at £4.28/kg into £10/kg retail product. Clearly the greater the quantity of quality salmon flesh that can be stripped from a carcass the greater the value that can be obtained from the process. In the last 10 years improvements have increased the recovery yield by some 4%.
The team presented several videos showing how the salmon were hatched, grown in pens then harvested for despatch to the factory for processing. The processing operation was usually split between several factories, the first stage being to gut and weigh the fish with a minimum of manual handling. Thus whole salmon packed in ice might be delivered to customers or to a secondary processor. At the end of this process each box is labelled to indicate its origin, quality and weight.
Further videos were shown that gave an insight into the secondary processing. It was here that most of the value was added to the product. Gains here are important as the processor expected to get a return on plant investment in less than 12 months.
The first operation was to remove the head. This represents about 10% of the fish so it was explained that it was important to cut accurately to maintain yield. The heads have some value, mainly going to Africa, either to be eaten or used to make soup. The fish are then de-slimed, which removes about 99% of bacteria.
Depending on what the customer, (supermarket), requires different processes follow. The fish will be filleted, (losing 11%), trimmed, (losing 5%), pin-boned, (losing 1%) and skinned, (losing 5%), as required. The filleting operation was claimed to be nearly as good as the best human operator, but of course the machine could maintain its quality level longer and perform faster.
One important part of the operation was the control of portion weight, over-weight portions representing lost revenue. Typically portion size can be held within 1g on a 220g pack. This was achieved by using laser scanning to continuously map the fillet profile and calculate the volume prior to cutting. (Similar techniques using lasers and cameras to distinguish between flesh and fat were used to control the filleting and trimming knives). One of the videos showed how the feed belt was opened up to discard the ends of fillets and to almost reverse so as to separate out the fish slices. Trimmings discarded at this stage are used as ‘make-weights’ or in ‘value packs’.
Further value could be added to the product by ‘cold smoking’ at 37 degrees or ‘hot smoking’ at 74-85 degrees, which is considered to be a cooked product.
After all these processes some 68% of the salmon flesh is recovered as a quality product. Salmon, being a natural product, brings its own problems. Apparently it is ‘near impossible’ to pin-bone it unless it is allowed to sit in iced-water for three days.
During the closing moments of the talk there was a brief mention of how important farmed fish were in feeding the world population, being 50% of all fish eaten, and how production was increasing at 3% per annum against a 1% growth of the human population. The talk ended with a brief overview of the company’s INNOVA software system that kept track of all the process stages, giving the operator, amongst other things, a real-time ‘dashboard’ report of the process.
My own experience of the food processing industry is restricted to a failed job interview at a canning factory and learning about ‘canning in-the-bright’, (product canned prior to be sold and hence without a label), and monitoring for metal, so the factory stages shown were completely new to me. It was interesting to see how the natural variability of the product was largely removed by clever measuring and routing techniques, bringing the packages to balance. As an eater of salmon it was fascinating to learn how clever engineering was able to get the most out of each salmon, not the least by minimising handling damage. While I appreciate that the processor/supermarket is driven to increase the ‘value’ of the product (i.e. price/kg) by smart cutting or packaging there is a bit of me, (my age?), that wishes we were still able to cut up our own. But that probably was an age where the people that did the cutting weren’t the people that got to do the eating! My final, (and probably not legal), thought is, wouldn’t a bit of enzyme in the water speed up the pin-boning?