Potato-peeling is an active and crucial stage of production and can have a decided effect on the quality and yield of the finished product. To achieve the desired outcome, Evie Serventi learns that today’s processor is looking for an energy-efficient, versatile peeler that minimises peel loss and downtime.
Peeling is one of the most important steps in potato processing and optimum yield greatly relies on the efficiency and effectiveness of the method of peeling and associated processes including washing, brushing, scrubbing and polishing.
The peel is removed by the use of heat, chemicals and mechanical abrasive methods. Knife peeling is still used, by hand for small volumes or by using drum-shaped mechanised knife peelers.Historically, common industrial processes were caustic or lye peeling, however today steam peeling and abrasive peeling dominate the market, depending on type and variety of products produced and intended capacity. Today’s abrasive (both batch and continuous) and steam peelers are commonly used by medium to large processors and are highly advanced. Lye peeling involves bathing potatoes in a caustic solution before both the skin and solution are scrubbed off – a method still employed by fruit producers (peaches) – but less so by potato processors.The peeling process can generate high levels of product loss which has guided equipment innovation and paved the way for quality monitoring and control systems to enter the market. Peeling is a process where less (peel) is more in terms of return on investment; key for every producer no matter the scale of production.
Odenberg designs total peeling solutions, post-peeling processes and sorting equipment, with an impressive international reputation across the fries, flakes and mash sectors. Its portfolio includes the patented Orbit™ steam peeling technology, Centrifugal Separator and Peel Scanner technology and more recently, the Starch and Peel Separator which focuses on the method of peel and starch separation, the drum design and hygiene.
Speaking from the company’s HQ in Ireland, Eamonn Cullen shared how the group’s dedicated peeling research and development team have reduced peel loss to industry leading levels and further streamlined the peeling process.
“The Starch and Peel Separator (SPS) is the next generation Centrifugal Separator, which uses centrifugal force to remove the loose peel from the surface of the peeled potato. For French fries, the SPS can eliminate the need to brush the product,” Cullen explained.
“This technology provides the lowest possible peel loss and removes the need to use a brush for dry peel separation for most applications. The main process improvements relate to the method of peel and starch separation and drum design. The result of these design improvements have provided the customer with the minimum of peel loss (less than 0.2 per cent).”
Processors are concerned about efficiency in terms of lowest peel loss, highest performance and energy; and reliability and maintainability in terms of the highest uptime and lowest maintenance time. Vanmark general manager Tom Mathues agrees, adding service to the mix.
“Probably the biggest concern is that equipment will actually do what the manufacture says it will do. Also, customers want reassurance that the manufacture will stand behind their equipment and be there for future support if needed,” he said.
“We are experts at trouble shooting, and offering suggestions on how to handle roll configurations, and pretty much anything that could ever come up. It’s awfully nice to be able to pick up the phone and talk to an expert that can solve a potential problem in seconds,” Vanmark’s general manager reflected.
With strong roots in the potato industry, the US-based firm has supplied food processing equipment worldwide for 50 years, with recent advancements including the high volume Peeler/Scrubber/Washer series. The latest model, the 2920/2922, comes standard with the innovative Natural Flow Gate which significantly improves peeler efficiency.
The Netherlands-based Marcelissen bv, which manufactures food processing lines for potatoes, root crops, fruit and other vegetables, works on the principle of “preventative service and good maintenance”, said the company’s Marlon Treuen.
Washing is a core part of the peeling process, serving several functions like removing the mud, dirt and sand off the potatoes; to help inhibit sprout control and for post peel rinsing. Processors are under increasing pressure to maximise water efficiency by recycling or simply using less.
“Odenberg’s Orbit steam peeler uses a dry exhaust system to minimise water use,” Cullen said.
“Water recycling is very important for post peel rinsing of the steam peeled product. We have developed washing systems that give more efficient product to product washing action, which reduces the amount of water required. This system uses up to 80 per cent of recycled water. This is achieved by using water reclaim equipment to remove the solids from the water,” he said.
Mathues concedes customers’ growing interest in water efficiency, an area the company is prioritising in terms of research and development. For example, to combat post-filtering starch clogging, peel residue and waste stream filtering systems are feasible.
“We are working with outside companies to develop more affordable filtering systems targeted specifically at our style of machines. There is no question that significantly reduced water usage and lower waste stream loads are high priorities of nearly every processor. A lot of processors have their own waste water treatment facilities, and recycling water is an ongoing process in the industry,” Mathues said.
Reducing energy consumption can mean better bottom line results and also adds value to a processor’s corporate social responsibility (which feeds back into improved bottom line results).
Mathues said the energy efficiency of peelers has improved and that today not only do all Vanmark peelers have a 90 per cent energy efficient motor as a standard feature, which is realised in monetary savings, there are several other areas where efficiency can be fine-tuned.
“Bearing drag and peeling surface efficiency all contribute to energy usage,” he said.
“In all of our new designs our drive systems have been specified with sealed for life bearings that have proven to be very durable. This means that bearing wear, which adds drag, is significantly reduced hence adding to energy efficiency.” Odenberg’s Peel Scanner 2 technology has taken monitoring and control to new levels. So far there are 10 units of the firm’s latest model, the Peel Scanner 2, which was released about six months ago, in large French fry factories. Cullen said three of which are of the top five French fry processors.
The Peel Scanner 2 automatically inspects the potatoes post steam peeling and automatically adjusts the steam peeler steam time, in 0.25 – 0.5 second intervals. The PS2 also inspects for defects levels (rot, scab and green) and monitors the length and width of the product.
“This is the first time the customer sees the quality of the incoming peeled potatoes. With the peel removed you can see the real quality, the remaining peel, the level of defects (Scab, rot, green, etc) and the length and width distribution. Inspection of the quality at this stage is critical to determine the downstream equipment process parameters,” Cullen explained.
“The objective is to remove as little raw material as possible, but still achieve peel removal that meets the customer’s end product specification. The percentage peel removal will vary depending on the end product specification and the scanner allows you to match the end product specification quickly and simply,” Cullen elaborated.
The peeling product manager revealed that in terms of energy projects, the company has just introduced a new heat recovery and emission control system to overcome problems inherent in current systems – stay tuned.
Sanitation means compliance and regular audits and strict product specifications along the entire supply chain. Processing equipment must meet local government regulations and have specific documentation attached.
“There are strict rules and regulations we must consider while constructing a machine. We need to mount special safety covers and strong constructions/frames,” said Marcelissen marketing manager Marlon Treuen.
“All of the standard industry requirements are met, including moving parts guarding, lockable compartment guarding, plus more,” adds Mathues.
“Hygiene is very important. End users complete regular audits of our customers process lines and we have to make sure that the Odenberg equipment complies. We complete regular reviews of the equipment to assess the clean ability and to ensure that all areas of the equipment can be cleaned correctly,” Cullen revealed.
With food born illnesses a contentious and regular that’s given plenty of media coverage, Mathues thinks there is a social awareness for proper food handling. “Anything you put in your mouth is important, or should be. All of our food grade equipment is manufactured out of 304 stainless or better and sanitation requirements go to the front of the list when designing equipment,” he added.
According to manufacturers, reducing downtime is paramount. Unscheduled downtime can hinder production and waste energy. So can weak or poorly designed components that are difficult to clean and maintain. Manufacturers agree that reducing stock and offering durable components reduces downtime.
Odenberg’s new XP Valve technology increases valve lifespan by over six times compared to those provided by competitors. “The technology replaces other manufacturer’s valves which typically failed, during production, after a period of three months or less,” Cullen said.
“Our machines minimise the number of moving parts in the equipment. With the design of the SPS we reduced the number of components to stock and maintain by over 40 per cent. All drum drive bearings are outside the chassis which means they are easy to inspect, maintain and lubricate. There are no couplings to line up/maintain and removal of drive assembly made easy with rollout support brackets,” Cullen added.
Vanmark continuous peelers comprise poly chain belting and sealed composite bearings, requiring no maintenance. Poly chain belting and associated pulley profiles are a more refined form of timing belt and have significantly stronger reinforcing belting and a stronger tooth profile. “Together these have made belt failures that occur after a significant run time in the earlier timing belt applications a very rare occurrence,” he revealed. The company has not replaced a poly chain belt due to normal wear failure in over four years of field exposure.
Marcelissen’s latest continuous knife peeler offers flexibility for clients plus increased capacities by being incorporated with other equipment. Treuen explains: “To achieve the best result a knife peeler can be placed behind an abrasive peeler and used to smooth the surface of the product, which is left with a raw finish after being washed and peeled by the abrasive peeler.”
Vanmark’s 2420 series means small-volume processors can use a continuous peeler specifically designed for lower throughput rates; and also gives larger processors the opportunity to try an inexpensive machine for new products or new recipes. Mathues added that it can also be handy for large processors during surge situations. Does this mean processors across the board are looking for multi-purpose peelers?
“Absolutely!” Mathues enthused, adding that small clients that deal with a variety of products benefit from their equipment’s quick roll changes.
“We can wash and polish potatoes requiring no peel removal for a gourmet potato bar, peel potatoes and carrots for a wholesale distributor in the afternoon, and then wash the little black bumps off the really small cucumbers for a pickle processor, all in the same machine, in the same day,” he said.
“When processors realise how efficient each process can be after a specific set up is developed for a given product, the market often tends to grow based on improved processing costs. This allows the processor to sometimes justify having a specific machine designated for the new market generated. We have some customers who have started doing five or six different products in the same machine and then growing the business accordingly.”