How improved product cleaning on the eviscerator can reduce rejections and improve quality

In a previous article, we already elaborated on the hurdle-to-hurdle concept. We explained how hurdles in poultry processing prevent dirt and bacteria from passing on to the next processing step. In almost all cases, a hurdle consists of a washing step: a nozzle on the machine or cabinet dedicated to this function. The better dirt and bacteria are removed, the less likely bacteria are passed on further into the process, and eventually end up in or on the end products. By having the right hurdles in the right place in your process, you ensure the hygiene level and quality of your products.

Despite having implemented the correct hygiene procedures, contamination and rejections can occur in the evisceration step. This means that even with the standard process setup, including standard cleaning after the plucker, venter and opener, contamination and rejections can still occur. Therefore, it is important to wash the products effectively and immediately in or after every process step. In this article, we describe the hygiene aspect of the evisceration step in poultry processing in detail.

The evisceration process

In poultry processing, the evisceration process is a key step where the intestine pack is removed from the breast cavity. Nowadays, this is done at speeds of up to 15.000 birds per hour or even faster. Lots of development effort has been put into OEM equipment to achieve the best possible performances. However, the evisceration process remains a complicated step, among other things due to product weight and size variations.

Critical factors for the hygiene performance of the evisceration process

The carcass is opened and prepared for evisceration by the venter and opener. In these steps, it can come to contamination or damaged intestines. In general a ‘spoon shaped tool’ enters the breast cavity and scoops the whole intestine pack out of and away from the carcass. The pack is then transferred into a pack conveyor line. All of this needs to be done without damaging the intestine package! Critical factors that can be identified for the hygiene performance of the evisceration process are:

1. The crop, stomach & intestinal tract must be empty: the birds must be sober
2. Avoid damage to the gall bladder
3. Avoid damage to edible red organs such as the heart, liver and kidneys
4. Correct separation of oesophagus and crop/stomach

There are other important factors, but these are crucial to hygiene and product quality. Some have direct hygiene and shelf life consequences, whereas others cause regulatory rejections.

Pollutions & contaminations caused in the evisceration process

The main causes for contamination and pollution occurring during the evisceration process are (i) damaged intestine packs, which could be damaged in either the venter, opener or eviscerator itself, and (ii) birds that are not completely sober.

(i) Damaged intestine packs can contaminate the whole breast cavity in the eviscerator. The evisceration process contains three steps: the vent opener, vent cutter and eviscerator. Hence, performance issues in the vent opener or vent cutter cause contamination in the eviscerator.

(ii) During the evisceration process, carcass pollution occurs especially when the broilers are not sober. Incorrect feed withdrawal may be the cause of this. As a result, the stomach and intestinal tract still contain feed and faeces. Especially in light weight pre-loaders flocks, this occurs often.

Main issues that occur in the evisceration process are:

1. Visual contamination
2. Faecal contamination
3. Gall fluid contamination
4. Parts and remains of damaged edible red organs or tissue in the breast cavity

After the eviscerator, the carcass is empty, and the breast cavity is open and accessible to clean both inside and outside. This is the first opportunity where the contaminations are accessible and can be cleaned and prepared for inspection.

The importance and benefits of washing after evisceration

Bacteria fixate to the product over time, and gall fluid causes discoloration. This is why it is vital to wash both bacteria and gall immediately after the contamination took place. When removed immediately after the evisceration, all the visual contamination can be washed off.

Compared to standard OEM cleaning solutions, Undine® is much more effective. The Undine® technology improves hygiene, because of the turbulent air/water mix with high velocity water droplets. It cleans the inside and outside of the carcass very effectively. Installed directly on the eviscerator, this mix removes dirt immediately after the pollution has occurred.  

Besides the improved hygiene and product quality, this washing position also reduces the number of rejections at the veterinary quality check. Rejections due to visual contamination can be reduced and even eliminated.

No machine runs at 100% performance. For example, an eviscerator performing at 99% performance in a double shift operation easily causes 1500 rejections day! This results in a very quick return on investment. And as mentioned before, the evisceration process is a cooperation of the vent opener, vent cutter and eviscerator. If, for example, the vent opener or vent cutter is also performing at 99%, this leads to another 1% rejections, adding up to 2% rejections.

We know which solutions are right for you

Would you like to know more about hygiene in the evisceration step? Or would you also like to improve hygiene and save on water, energy and personnel costs? Please feel free to contact our experts. They are happy to provide personal advice. Which solutions suit you best, depends on your specific plant configuration and products.