By Carl R. Hoffman

Growing demand for whey products
Whey, once an environmentally troublesome waste product of the cheese making process, is becoming an increasingly significant revenue stream for US cheese producers. Whey protein concentrate is dried and sold for use in many products, including: nutritional beverages, baked goods, processed foods and animal feed. Lactose that is removed from the whey can also be dried into powder and sold for use in infant formula and pharmaceutical applications.
At Brewster Dairy, Inc., the country’s largest manufacturer of all-natural Swiss cheese, whey products now contribute a full 25 percent to the company’s bottom line. Each day of the year, more than 1.3 million pounds of milk is delivered by truck from approximately 275 local farms to the company’s Ohio facility. Nearby dairies cannot produce enough milk to meet Brewster’s needs, so condensed milk is shipped in from California, Georgia, New Mexico and Texas to supplement the local supply. After pasteurization, the whey is separated from the milk curds. Swiss cheese is made from those curds and the whey byproduct is processed through a membrane ultrafiltration (UF) system.

The UF system produces whey protein concentrate (WPC) by removing sufficient non-protein constituents, including lactose, so the finished product contains the protein level desired. The Brewster plant typically produces WPC-34—whey protein concentrate that contains 34 percent protein on a dry weight basis. It is also capable of producing WPC-50 (50 percent protein on a dry weight basis).

In 1998, Brewster Dairy purchased a second Swiss cheese plant in Stockton, Ill. and today the two locations annually ship about 13 million pounds of whey powder and 11 million pounds of lactose powder. In early January 2007, the company purchased a plant in Rupert, Idaho from Kraft Foods and announced that the facility will be converted to the production of Swiss cheese and whey products as well.

Need to control costs
The market for whey products has emerged from the confluence of three factors. First, the development of membrane filtration technology has provided an efficient and cost-effective method for separating and concentrating whey protein. Second, due to environmental concerns, disposal of whey is no longer economically viable, even if legally permissible. Third, demand for whey products has increased as less-developed nations industrialize and the healthful benefits of whey proteins are recognized globally.

“Despite the strong demand for whey products, WPC-34 and WPC-50 are commodities and therefore pricing is as important in our market as product quality,” said Ken Shook, Supply Chain Manager at the Brewster plant, “Our profitability depends on controlling the cost of production.”

UF is a capital-intensive process and long membrane life is essential to controlling costs. “Long membrane life translates directly to lower membrane replacement costs,” according to Shook. “Therefore, the challenge is to minimize the membrane degradation that can be caused by the frequent exposure to chlorine during our daily clean-in-place procedures.”

Extended membrane life
The Brewster plant has installed UF spiral membrane modules composed of a proprietary polyethersulfone (PES), which features a patented fused-fold protection system that dramatically reduces degradation caused by chlorine exposure, resulting in significantly longer service life.

“We originally installed the UF system in 1983 and have continually returned to the original manufacturer for replacement membranes because of their high durability and longevity,” said Shook. “We upgraded the membrane elements in the mid-1990s when these new long-life modules were introduced. We have found they last twice as long as any other membrane available.”

The UF system at the Brewster plant contains four stages in series, with 14 housings per stage and three membrane elements per housing, for a maximum capacity of 168 elements.

Durability with ease of maintenance
“The UF system is one of the three key processes in our production of 1.5 million pounds of fluid whey each day,” said Shook. “The system and its membranes are so durable, dependable and easy to maintain that our operators can focus on the two other key processes, the evaporators and pasteurizers.”

“The system has been running continually for more than two decades, 364 days a year. We have hardly needed to change anything—only an occasional motor or valve. The individual UF membranes have a long service life—it typically exceeds 18 months. We attribute the long service life to the quality of the membrane construction and to the extensive training we have received from the manufacturer on critical pretreatment processes.”

Return on investment
“Brewster Dairy chose the fused-fold protected membrane because it makes good economic sense,” said Shook. “We get a good return on the investment we make in high-quality membranes, as our total production costs are reduced because of the long service life.”

The elements also provide the economic benefit of maintaining the same high level of protein rejection for the entire life of the membrane. The superior construction reduces the risk of losing valuable protein product due to leakage. Moreover, longer service life reduces the costs and inconvenience of membrane changeover procedures.

According to Shook, “these elements have helped us control our production costs, so that we can compete effectively in the commodity market for whey protein concentrate.”

About the author
For the past 30 years, Carl R. Hoffman has worked for Koch Membrane Systems in various roles in the marketing and sales of filtration systems worldwide. In his current role as Market Manager, Food and Beverage, he is responsible for the sale of filtration products in the Americas. Hoffman has a Bachelor of Science in chemical engineering from Tufts University and a Masters of Business Administration in marketing from Boston College. He can be reached at (978) 694-7176 or by e-mail at [email protected].

About the product
The membranes used in Brewster are XL-1000 HFK ultrafiltration spiral membranes from Koch Membrane Systems, Inc. (KMS), of Wilmington, Mass. The XL-1000 modules are composed of a proprietary polyethersulfone (PES) membrane and feature a patented fused-fold protection system that dramatically reduces degradation caused by chlorine exposure.

About the company
For over 30 years, Koch Membrane Systems (KMS) has been developing and manufacturing state-of-the-art membranes for food, dairy, juice, wine, vinegar, beverage, industrial water, municipal water, ultrapure/high purity water, automotive, pharmaceutical, petrochemical, textile, desalination and scores of other applications worldwide. KMS provides tubular, spiral and hollow fiber membranes for microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). KMS also provides submerged membranes for membrane bioreactors used in industrial and municipal wastewater treatment. More than 15,000 installations use KMS membranes and are operating and performing successfully around the world. Contact Koch Membrane Systems, Inc. at 850 Main Street, Wilmington, MA, USA 01887-3388; telephone: 1-888-677-5624; local telephone: +1-978-694-7000; fax: +1-978-657- 5208 or via email: info@kochm Visit the company’s website at www.koch


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