by Emerson Jiménez Barajas, Application Director, FAM & Stumabo International

Precise cutting is an important step for most of the potato processing plants as it is during this step that the shape of the final product is defined. This step has seen some important innovations in the last five years but there are still some challenges that could be addressed in the future.

Quality & Capacity

The main points that potato processors are looking for are good quality and improved capacity or yield, which are both related.

Quality is a somewhat subjective parameter as it depends on the expectations of the processor and the final customer, but there are some elements that define if the quality is good, like the slice thickness consistency, the amount of scrap or off-cuts. It is also a general rule that when the processing line is not producing a good quality product, the capacity of the line is also affected as more scrap or off-cuts are produced and therefore less final product comes out of the line.

Therefore, when a potato processor is working on quality, the yield of the line will also be positively affected.

Scrap or off-cuts have a big impact on quality. These are generally small pieces that do not correspond to the quality specifications. They are normally produced because of the shape of the produce, but they are also originated when the produce is not stable during cutting, or when the knife is not stable, or is not sharp anymore. It can also happen when something is obstructing the path between the produce and the knife.

FAM and its sister company Stumabo International have been developing new technologies to address these different issues. The patented and patent pending centrifugal technology was designed to stabilize all the components and the produce during the cutting process. Stability is key in any potato processing facility, especially when the conditions of the produce are constantly changing.

Other improvements were done in the materials of the blades to have a more resisting cutting edge that keeps it sharpness longer or that resists better the impact of foreign objects. And finally, it was also important to consider that a stable product and a sharp knife could not work properly if there is something in between affecting the cutting process. Therefore, some features were added to the cutting systems to allow any foreign element to exit the cutting area and reduce any interference between potato and blade.

You can read the rest of this article in your complimentary e-copy of the July/August Issue of Potato Processing International magazine, which you can access by clicking here.

by Robin Ostermeier, Stefan Töpfl, ELEA

Plant cells, e.g. potato cells, soften when subjected to the PEF treatment, as they lose their internal cell pressure (turgor). Due to controlled texture softening of tubers, cutting is improved, resulting in less starch loss, and therefore increasing product yield. Less feathering also decreases oil uptake during frying. Facilitated moisture release allows reduced frying time and temperature, which can lead to a production capacity increase and improved product appearance. 

PEF Benefits in the Snack Industry

Whilst the cell membrane´s function is to control mass transport into and out of the cell, an electroporated membrane allows mass transport. The most visible effect after PEF application is water leakage out of the cells, reducing the turgor pressure and resulting in an overall softer, and easier to cut raw material. This allows an easier processing of fresh from the field crop or hard raw material such as sweet potato and helps to equilibrate naturally occurring variability within the raw material. As vegetable tissues after PEF cut better and show less breakage or rupture, the reduced turgor pressure allows more complicated cuts, such as deep ridge, waffle or lattice. The treatment results in a smoother cutting surface and less wear of the cutting blades, reducing the knife service intervals. 

Furthermore, as fewer cells are mechanically damaged by cutting, the number of fines, debris and starch released into processing water is reduced during cutting. Less fines and broken particles translate into less product waste and increased yield. The lower extent of free starch on product surface also reduces the number of chips sticking together during frying. In addition to that, improved cutting causes less cracks in the product surface. Those are the pathways for oil entering during subsequent frying. Notably oil entering those capillaries will also be difficult to remove even with defatting equipment. Reduced mechanical tissue damage after PEF will lead to a reduction of fat uptake of 10 % for typical product and frying conditions. Due to the PEF-induced open cell structure water leaks out from the slices during processing. This increases the amount of free water on the chips surface and leads to the formation of a vapor layer on the surface of the chip during frying, reducing the amount of chips sticking together in the fryer. As a result, less rejects can be observed. 

You can read the rest of this article in your complimentary e-copy of the May/June Issue of Potato Processing International magazine, which you can access by clicking here.

Steven B Johnson PhD is a crops specialist and extension professor with the University of Maine in the United States. We asked him what it takes to grow the perfect potato and what the chances of genetic modification would be.

Is Genetic Modification a viable option for potato production: are there benefits in terms of nutrition, yield?

GM potatoes are a viable option for potato production. Modifications to the nutritional value of the potatoes are certainly a possibility. Reducing pesticide use and protecting the stored crop are great opportunities for GM potatoes. Consumer acceptance is key to the future of GM potatoes.

How enthusiastic are producers and processors in terms of new ideas, for example Ethylene?

As a rule, I find producers and processors are eager to try new approaches. However, they run the economic numbers to the new approaches after feasibility studies have been performed and evaluated. Both groups are in business and regularly assume risk but neither want undo risk.

Steve, do you agree that it is necessary for the links between producers (growers) and processors to be strong, to ensure optimal use of the product?

Yes, I do. If links aren’t strong, neither does well. While there are times the relationship is tense, producers and processors need each other and have to work together.

What are your current research projects?

I am investigating temperature and humidity variations within potato storages, several potato-pathogen interactions, different approaches for sampling of field populations of pests. We are also working on several computer modelling applications.

From country to country, are there marked industry differences in terms of research and development?

From my experience, yes.

If so, what are they?

The link between some industries and academic workers appears to be stronger in Europe that in the US.

Is there much international cooperation in relation to research and development between countries?

There are some notable US projects but really not enough of them. European countries tend to be more advanced in this aspect that the US.

The potato sits close to the top in terms of being a global food crop. Do you foresee the potato strengthening its position; particularly in developing countries?

Yes I do. The potato is highly adaptable and produces well under many environments. Potatoes are widely grown in developing countries. Adoption of GM in some instances may produce and protect more produced food.

In your opinion, are there any current issues producers and processors need to address?

Food safety is an ever increasing concern.

How do you prefer eating the humble spud?

It has to be mashed with milk and butter and whipped with a blender. I have been known to eat chips and crisps as well!