PEF technology aims to revolutionize fruit and vegetable processing
Dutch-German company Pulsemaster has launched a new compact, industrial-scale pulsed electric field (PEF) system that’s designed to treat fruits and vegetables.
The process involves tissue softening before dehydration and freezing to extract water and preserve cellular structure, organoleptic properties and flavor.
Launched at Anuga FoodTec 2024, held in Cologne, Germany in March, Pulsemaster’s PEF technology offers processors several benefits, including improved product quality, higher processing capacity and enhanced yield.
HARNESSING THE POWER OF ELECTROPORATION
According to Mark de Boevere, general manager and founder of Pulsemaster, the compact PEF system benefits fruit and vegetable processors in several ways. The technology uses short, targeted electrical pulses to disrupt and open plant cells via electroporation. The treatment increases internal diffusion, which results in improved mass transfer.
The technology is especially effective in high-water content produce such as onions, garlic, peppers, strawberries and mushrooms. Treatment takes just one second, and the unit has the capacity to process 10 metric tons (22,000 pounds) per hour.
“With PEF, we’re drilling miniscule holes in the membranes of the fruit cells,” De Boevere said. “Why in the membranes and not in the cell walls? Because membranes are electrically charged. Drilling minuscule holes in the membranes enhances mass transfer of internal liquids going out of the cell.”
Prior to processing, extracting a portion of the free water from the produce helps preserve cellular structure and organoleptic qualities.
“It enhances the quality of the end product and the process goes faster,” said De Boevere. “Pulsed electric field and fruits and vegetables — it’s a very good combination if your objective is extraction, drying, cutting or freezing.”
BENEFITS FOR POTATO PROCESSORS
Following PEF treatment, french fry potatoes require 40% less cutting force, De Boevere said. Breakage can be reduced from 3% to less than 0.5%.
“You have smoother surfaces and there is no feathering,” De Boevere said. “This means less oil absorption in the fryer.”
In potato chip production, the main benefits of PEF treatment are easier cutting and smoother surfaces, which means less oil absorption. Because PEF helps remove moisture from potatoes, fewer chips stick together, which minimizes the risk of doubles.
“The chip processor is making a more crispy crisp,” said De Boevere.
“A french fry processor or a crisp processor who starts to use PEF can increase the yield of his entire line by approximately 2%,” he added. “That’s huge when you look at the whole year.”
TOMATO PROCESSORS REAP ENERGY SAVINGS
It’s not just potato processors who reap the benefits from PEF. De Boevere said that PEF offers opportunities for tomato processors as well, especially in terms of energy savings.
As industry moves from gas to electricity, PEF technology finds itself in a unique position. Because PEF uses energy to create pulses, it does not require continuous energy, a fact that further contributes to its energy efficiency.
Following PEF treatment, removing the skin of the tomato is very easy, De Boevere said.
“You can almost remove the skin by hand,” he said. “PEF enhances the peeling of tomatoes without using a lot of steam. In fact, you can reduce steam usage by up to 50%.
“This is huge for energy savings and improved quality.”
Heat is a destroyer of nutrients, color and taste. Using less steam, therefore, helps to preserve nutritional and product quality.
“If you take a PEF-treated tomato and you take off the skin and eat it, you have a much fresher taste,” De Boevere said.
PEF ENHANCES JUICE YIELD
PEF also improves the extraction of juices, according to De Boevere. Applying PEF to fruits and vegetables before juice pressing enhances overall juice yields.
PEF can also be used as an alternative to pasteurization. Traditional pasteurization is a function of maintaining temperature for a certain amount of time.
“With PEF, you treat your juice or smoothie within one second, and then you have extended shelf life,” he said. “You have made it food safe at ambient temperature, and you maintain organoleptic qualities like taste and color. You also maintain vitamins.”
Shelf life of fresh pressed juices is normally somewhere between five and seven days. With PEF, shelf life can be extended to between 21 and 25 days, De Boevere said. This allows processors to make larger volumes in a single batch.
“This is a big step ahead for fresh juice processors,” he said.
De Boevere said the system is also being used for juice extraction and french fry and chip processing. There has been interest from tomato processors as well, he said.
