Not much has changed with milk pasteurization over the past 100 years — until now. Vaquería Tres Monjitas is the first food and beverage manufacturer to use a new cutting-edge pasteurization technology that significantly extends the shelf life of fresh milk without sacrificing nutrition or taste, helping the San Juan, Puerto Rico-based dairy processor to differentiate its fresh milk products and create a new category in the dairy market.
Tres Monjitas has been a household name in Puerto Rico for more than 100 years, selling milk and other dairy products on the island. After celebrating its 100th anniversary in 2018, Tres Monjitas began looking for ways to drive sales of its fresh milk, especially given the decline of milk consumption in Puerto Rico. In addition, 61 percent of consumers in Puerto Rico who buy fresh milk use the expiration date on the package to determine which brand of fresh milk to buy, according to research conducted by Tres Monjitas. So the company began investigating technologies that could extend the shelf life of its fresh milk products. That’s when Tres Monjitas came across JCS Process & Control Systems, the Rochester, New York-based company that designs process and control systems primarily for the food and beverage industry.
Best of both worlds
JCS recommended that the dairy processor use Millisecond Technology (MST), a patented pasteurization technique that JCS spent 15 years developing for commercial use. Millisecond Technologies Corp. owns the patents for MST, but JCS has the exclusive rights to manufacture, integrate and market the technology.
According to JCS, MST offers the benefits of both high-temperature short-time (HTST) pasteurization and ultra-high-temperature (UHT) pasteurization — the two main pasteurization methods used by the dairy industry — without their shortcomings. HTST pasteurization allows manufacturers to produce what the dairy industry calls fresh milk. It involves heating milk to between 161°F and 175°F for about 15 seconds, followed by rapid cooling. This type of pasteurization doesn’t damage the nutritional components or flavor of the fresh milk, but only offers about two weeks of shelf life. On the other hand, UHT pasteurization heats milk to between 280°F and 292°F for about two seconds and then flash cools it. Because milk proteins denature and milk solids burn between a thermal range of 180°F and 220°F, the UHT process can mar the flavor and nutrients of milk. Therefore, the milk cannot be marketed or labeled as fresh. But UHT pasteurization kills more bacteria than HTST pasteurization and, therefore, offers a longer shelf life. UHT milk is typically perishable within one or two months. However, UHT milk can last for up to one year unopened in aseptic packaging and up to six months unopened in extended shelf life packaging. The low temperature and low pressure of MST allows dairy producers to retain the nutritional components and flavor of their milk products, letting them market the products as fresh milk. Yet, MST gives milk a much longer shelf life than HTST pasteurization — offering about 30 days or more of shelf life, according to JCS.
In May, Tres Monjitas switched from HTST pasteurization to MST to pasteurize its fresh milk products. The company retrofitted its existing heat exchanger with an MST chamber. When the raw milk arrives at Tres Monjitas, the milk undergoes laboratory testing to ensure it meets quality requirements and then moves through a series of filters. The filtered milk is pumped into the MST chamber, where it is subjected to a temperature of about 140°F. As the liquid is pushed through a spray nozzle, it forms into small droplets at a speed of 10 meters per sec. The chamber increases the droplet temperature to about 158°F, while the pressure drops to between 150 and 160 psi. Unlike a stream of liquid, the droplets don’t have much cushioning to protect the microbes that may be in them, leaving the bacteria unable to survive the shock that comes when the temperature increases and the pressure declines suddenly in the droplet. That shock ruptures the microorganisms’ protective membrane and destroys the bacteria, achieving an efficient 8-log bacteria reduction that can extend the milk’s shelf life without damaging its nutritional components and flavors. The milk then undergoes HTST pasteurization in order to comply with the food safety regulations of third-party agencies, including FDA.
“The thing that is unique about [MST] is that nobody thought to form droplets out of the milk to explode the microbe,” explains Philip R. Frechette, founder and CEO of JCS.
Milking the benefits
By using MST pasteurization, Tres Monjitas has been able to extend the shelf life of its fresh milk products from 12 or 13 days to 33 days. That has helped the company minimize yield losses, decreasing the amount of expired product that retailers pull off their shelves and return to the company. It also reduces Tres Monjitas’ wastewater treatment costs because it now disposes of less milk. “That equates to about 18 percent of the losses due to out-of-date-code milk,” says Orlando González, general manager for Tres Monjitas. “So if you can get the 30 days on your date codes, you won’t have as many returns.”
With the extended shelf life of its fresh milk products, Tres Monjitas is now able to expand to new markets outside of Puerto Rico. As the first company to commercially use MST, Tres Monjitas purchased the exclusive rights to use the technology for distributing its fresh milk products in Puerto Rico and the U.S. Virgin Islands. The longer shelf life means the products can travel farther and can differentiate themselves from other milk brands that use traditional pasteurization methods because Tres Monjitas’ fresh milk products are in a category all its own, according to González.
“[MST] really offers us the opportunity to enter new dairy markets like the Virgin Islands because we are now more competitive in relation to other dairy companies,” he explains. “Most of them are producing UHT-processed milk with more than 30 days shelf life or HTST milk with a shorter shelf life. We are able to compete with them because we’re in a different category: fresh milk with a long shelf life. It is the perfect match of shelf life and flavor. It stands out in the coolers with our customers.”
“This new technology takes pasteurization to new levels,” González adds. “With MST, we are the first long-life pasteurized fresh milk in the world with the same great flavor and nutritional value.”