Striding briskly into a suite of Minneapolis Institute of Arts galleries, Anita Kunin nodded approval at walls lined with paintings by Georgia O'Keeffe, Marsden Hartley, Andrew Wyeth and others, all from the collection of her late husband, Minneapolis businessman Myron Kunin.

Then she glanced at a cart stacked with more of her husband's pictures. "That one I've never seen in my life," she said of "Two Nudes" by Marguerite Zorach.

Many Minnesotans will share her surprise when "American Modernism: Selections from the Myron Kunin Collection of American Art" opens Thursday, launching a yearlong centennial celebration at the MIA. Planned in secret, the unannounced exhibit is an 80-piece sample of more than 550 paintings, sculptures, prints, drawings and photos on loan from the Kunin family, with the hope it will become a permanent part of the museum.

Likely worth more than $300 million if it were ever auctioned, the collection is one of the most important hoards of American modernist art in private hands. Since Kunin's death at 85 in October 2013, its future has been unsettled. His wife and four adult sons would like it to remain at the museum permanently but cannot make any commitments until the estate is settled, she said.

"The kids feel the same as I do, that American art was somehow the symbolic essence of what Myron collected and we'd really like to keep that collection together," said Anita Kunin, 83. "If we can manage all of his commitments and ventures without selling any of the American art, we'd like to do that, but we do have to meet all his obligations."

To that end, the family auctioned Kunin's collection of African art in November for $41.6 million, an auction record for African art in New York. "We won't see a penny of that money," she said.

A transformative collection

Myron Kunin made his mark by buying his father's 15 barbershops and hair salons in 1958, and transforming them into Regis Corp., an international behemoth with at one point $2.7 billion in annual revenue and 9,763 stores worldwide. Before his death, he had sold his Regis stock and diversified into radio and TV stations, electronics manufacturing, real estate, children's shops and other ventures.

His collection, which includes nearly 400 paintings, would fill a huge void at the MIA, which is rich in European, Chinese and Japanese art but has very little American painting or sculpture. His earliest American pieces date to the 1830s but the bulk are figurative paintings from about 1900 to 1950, including portraits, nudes and circus performers, landscapes and seascapes, social narratives and some abstractions.

"The focus of the Kunin collection is American modernism, so with it we can really tell the story of the early 20th century, which is an area we're especially weak in," said Kaywin Feldman, the museum's director. "There are at least 12 Marsden Hartley paintings in the collection, plus four or five John Singer Sargents and three by the folk artist Horace Pippin. Having significant artists like that in such depth is very exciting."

As a collector, Kunin kept a low profile, hanging most of his pictures at Regis headquarters in Edina and keeping only a few at home. He generously lent art to museums around the country, but kept his name off the labels and had no patience with the obsequious flattery that wealthy collectors often attract. He preferred gutsy pictures that often had a narrative edge to them and, though he owned plenty of big name talent, he was more interested a painting's quality and psychological punch than who made it.

"He didn't have time for the celebrity aspect of art," said Robert Cozzolino, senior curator at the Pennsylvania Academy of the Fine Arts in Philadelphia. "He didn't want people to tell him what was great; he wanted to feel it by looking at it."

He began collecting in the late 1970s and educated himself by taking seminars at Yale and Winterthur, a museum-training program in Delaware. On business trips to New York, he'd set aside time to roam the galleries, quiz art dealers and sit in on lectures at New York University. His expertise won him a seat on the art acquisition committee at the Whitney Museum of American Art in New York City and a board position at the Pennsylvania Academy.

He was on the MIA board of directors for 35 years and, during his lifetime, gave the museum 230 paintings and other art then worth nearly $10 million.

Top art for top dollar

Putting a potential price tag on his collection is challenging because American art of that era is more often sold through private galleries than at public auction.

It was out of favor and comparatively inexpensive when Kunin began collecting it 35 years ago, but prices have risen significantly. They can vary wildly, even for the same artist, depending on the work's subject, size, quality, condition and "provenance," or history of ownership.

In November, Sotheby's in New York sold three O'Keeffe paintings from the artist's namesake museum in Santa Fe, N.M. "Jimson Weed," depicting a morning-glory-like flower, brought $44.4 million, an auction record for a female artist, while a landscape went for $5 million and a still life for $941,000.

Nevertheless, it's possible to derive a ballpark figure of $300 million for Kunin's collection based on conversations with curators, art dealers and recent Christie's and Sotheby's auctions of American art typical of his taste.

That "could actually be near the approximate value an auction house would peg on the group," confirmed Phil Alexandre, a New York dealer who, in the past six years, sold about 20 of Kunin's paintings to private collectors and museums.

Kunin was always a reluctant seller who loved every piece he owned and negotiated long, Alexandre said. But he did part with pieces occasionally to cover a business deal or, more often, to buy more art.

"Myron Kunin's passion for art showed in the quality of what he acquired and the way in which it occupied every space in his life, at work and at home," said Wal-Mart heir Alice Walton, founder of the Crystal Bridges Museum of American Art in Bentonville, Ark., which bought some of his art. "I greatly admired — and sometimes found myself battling against — his single-minded determination to acquire the very best."

Mary Abbe • 612-673-4431