Wise Co., a maker of freeze-dried and dehydrated food founded less than four years ago, has seen sales skyrocket. But its owner had greater aspirations for growth and knew he needed more capital investment and professional expertise to get there.

So, in October, Brian Neville sold a majority interest in the Salt Lake City company to Trivest Partners, a Coral Gables-based private equity firm, to help steer its future course.

“The reason for the partnership with Trivest was to continue on that rocket ship and go to levels we couldn’t go to on our own,” said Neville, who continues to run the business as chief executive.

Often operating behind the scenes, private equity is a major source of capital for many private companies.

Choosing companies that have potential for growth, private equity firms generally buy a controlling interest, then work with management to improve the company’s performance and boost its value, with a goal to eventually sell the business a few years later, often to another private equity firm or to a larger company in the same field.

Private equity’s investment in established businesses differs from venture capital, which helps get a new company off the ground.

Some private equity firms focus only on healthy companies, while others choose distressed businesses they can turn around.

Yet whether it is revamping strategy, injecting new managerial expertise, improving sales and marketing, boosting production, distribution, systems or technology, streamlining costs or making add-on acquisitions, the private equity firm’s ultimate goal is to guide the business toward higher revenue and profits.

“Strengthening companies is the cornerstone of the private equity business,” said Noah Theran, spokesman for the Private Equity Growth Capital Council (PEGCC), a trade and lobbying group based in Washington, D.C. “And they do this by investing much more than capital. They bring fresh thinking and operational expertise to build stronger companies that are better able to compete in the global marketplace for the long term.”

However, critics of the industry say that private equity’s investment strategy, which typically includes piling on debt, can lead to severe cost cuts and job losses.

Regardless, private equity touches the lives of many in South Florida. You may work for or shop at a company that a private equity firm controls, or your pension fund may invest in a private equity fund.

In fact, public and private pension funds are among the largest investors in private equity funds, making up 43 percent of all private equity investment, according to the PEGCC.

The Florida retirement system, for past and current state employees, for example, has invested $5.6 billion in private equity. And the City of Miami Firefighters’ and Police Officers’ Retirement Trust has invested $31.3 million in private equity, the PEGCC said.

Trivest’s latest fund, which closed a month ago, is among the private equity funds in which Florida’s retirees have placed their money.

“We’ve invested in 11 private equity firms that invest in Florida — that is our mandate in the Florida Growth Fund,” said Greg Baty, principal with Hamilton Lane, which manages the Florida Growth Fund, a private equity fund whose primary investor is the pension fund for the state of Florida. Typically, private equity investments range from $5 million to $15 million, Baty said.