In this 2012 photo, chef Marcella Hazan poses in the kitchen of her Longboat Key, Fla. home. Hazan, the Italian-born cookbook author who taught generations of Americans how to create simple, fresh Italian food, died Sept. 29 at her home. She was 89. (Chris O'Meara/AP)

Marcella Hazan, the cooking instructor and best-selling author who propelled mid-20th-century America beyond canned beefaroni to a world of homemade pastas and what she called the “simple, true” cuisine of her native Italy, died Sept. 29 at her home in Longboat Key, Fla. She was 89.

The cause was complications from emphysema and arterial blockage, said her husband, Victor Hazan, who has written extensively on Italian wine. He sent word to their son, Giuliano, an expert on Italian food, not to cancel his scheduled cooking class in Valpolicella, Italy, because that’s what his mother would have wanted.

Mrs. Hazan, a biologist with two doctoral degrees, said she had never cooked before her marriage in 1955; her family in Italy had always relied on hired help. Her first trips to American markets were demoralizing and she likened them to a culinary graveyard: “The food was dead, wrapped in plastic coffins.”

Her husband, who was working for his family’s furrier business, encouraged her budding passion for re-creating the savory pleasures of her youth. She had “innate intuition” for cooking, he later said, because she “came out of a culture where food is a central part of life.”

But her professional cooking career was an accident. She was taking a class on Chinese cuisine in 1969 when classmates asked her for Italian recipes. Word soon got to the influential food writer and critic Craig Claiborne of the New York Times, who cemented her reputation in a feature article the next year.

Marcella Hazan was from then on a leading ambassador of Italian cuisine. Julia Child once called her “my mentor in all things Italian.” Her workshops in New York and Italy drew ordinary homemakers as well as the chef and food writer James Beard and entertainers such as Danny Kaye and Burt Lancaster.

Her cultural status was affirmed by the New Yorker cartoonist David Sipress, who captured her allure in a drawing for Gastronomica magazine a decade ago. He depicted two women in a kitchen, one telling the other about the image in a shrine over the stove: “It’s not a saint, exactly. It’s Marcella Hazan.”

For each of her six cookbooks, which sold millions of copies in all, Mrs. Hazan offered recipes that were clear, uncomplicated and dependable. This won the hearts of chefs, food critics, fellow cookbook authors and home cooks alike, and earned her first-name-only status on par with Julia.

Mrs. Hazan demanded the use of extra-virgin olive oil years before it became a staple of the Mediterranean diet fad. She taught people to put a lemon in the cavity of a roast chicken; to savor spaghetti sauced with garlic, olive oil, crushed red pepper flakes and flat-leaf parsley as much as any tomato sauce; and to notice the difference salt makes by smelling, not just tasting.

The genius of her four-ingredient tomato sauce — fresh or canned San Marzano tomatoes, butter, an onion and salt — freed home cooks from having to reconstruct the thick, overly sweet red blankets they’d pour from a jar.

If Child, a friend, gently criticized her for being “too much of a perfectionist,” Mrs. Hazan felt she had much to be exasperated about in trying to correct American cooking habits and trends she found ludicrous.

The tendency to oversauce, she once quipped, left her “depressed.”

On tomato-hued pasta: “I’ve lost the war on this.”

On sun-dried tomatoes: “I never cook with sun-dried tomato. That’s a pickle!”

Mrs. Hazan wrote in Italian, and her husband translated. She admired the way Victor captured her voice — one often noted for an edge of impatience during several decades of cooking classes.

“You learn a lot about teaching,” she told the New York Times in 2004. “You learn a lot about cooking from the questions. . . . Sometimes they’re stupid questions. And sometimes they make you think, ‘I need to explain.’

“The best ingredient in the kitchen is common sense,” she said.

Marcella Polini was born April 15, 1924, in Cesenatico, Italy, which she describes in her memoir as a quiet fishing town on the northern Adriatic Sea known for a small yet powerfully flavored sole called saraghina, and a canal designed by Leonardo da Vinci.

It was there that her tall and handsome mother, Maria Leonelli, met and married Giuseppe Polini, a respected tailor who had worked in Paris, Zurich and New York. The Polinis moved to Alexandria, Egypt, when Marcella was 2, so Maria could be reunited with her family.

Five years later, the young Marcella fell and broke her right arm. Complications, including gangrene, set in, and Maria took her daughter to Bologna to correct the problem. A series of operations left Marcella unable to open her arm fully and with a crooked hand. Yet she credits that turn of events with setting her life on a course that led to her career.

Even though her mother was a good cook, Marcella was interested in academic rather than culinary pursuits. In the early 1950s, she received doctoral degrees in biology and geology at the University of Ferrara in her native province of Emilia-Romagna. She met Victor Hazan about that time after she went home to Cesenatico to find work.

Besides her husband of 58 years, survivors include her son and two granddaughters, all of Sarasota, Fla.

The Hazans moved back to Italy in 1962, where Marcella was thrilled to shop and cook. They lived in Milan, Florence and Rome before returning to the United States in 1967. She packed school lunches for Giuliano of tortelloni, bean soups and fresh fruit that the boy’s peers made fun of, until she “resigned” herself to making sandwiches for him.

In Manhattan, Marcella had enough free time to continue courses in Japanese flower arranging that she had taken in Rome. Visits to Pearl’s, a Chinese restaurant, convinced her to try her hand at the new cuisine she loved. When the Chinese cooking teacher Grace Chu canceled after one class, Mrs. Hazan soon found herself teaching a menu of Italian dishes to six of her former classmates.

“Since they knew I made Italian food, they gave me a piece of paper with six names and telephone numbers,” she told The Washington Post in 2006. “So I said to my husband, ‘Americans, they are crazy!’ He said to me, ‘You like to teach? You teach.’ I never took another cooking class, because I got too busy doing my own.”

Claiborne, the food writer and critic, soon called about the classes and accepted an invitation to lunch at her apartment. She served tortelloni and veal scaloppine. This led to a published article, a lifelong friendship and the proposal to do a cookbook.

Her maiden book, “The Classic Italian Cookbook” first published in 1973, did not come easily because of her kitchen freestyle. “Every time I would measure,” she said, “I would forget what I was doing and the recipe would come out wrong.” Victor’s the one who put transparent coverings over bowls and pots, to catch and measure the ingredients she tossed in as she worked.

Although Mrs. Hazan called “Marcella Cucina” (1997) “the last book of her life” — for which she received a record-setting advance of $650,000 — she went on to write “Marcella Says: Italian Cooking Wisdom From the Legendary Teacher’s Master Classes With 120 of Her Irresistible Recipes” (2004) and the memoir “Amarcord: Marcella Remembers” (2008). A pile of manuscripts for a new cookbook, tentatively called “Ingredienti,” awaits her husband’s translation. It will be published in early 2014 by Scribner.

Mrs. Hazan appeared as a guest on television variety shows, dined with celebrities and ramped up her cooking classes at home and abroad. The sessions took days and included trips to the market and the chance to taste rabbit and guinea fowl. Bologna built a new kitchen for her cooking school there in 1978. Nine years later, she turned the school over to Giuliano.

Marcella and Victor Hazan retired to Florida in 2000. Mrs. Hazan received a lifetime achievement award from the James Beard Foundation that year and one from the International Association of Culinary Professionals in 2004. Les Dames d’Escoffier, an international organization of women in the culinary arts, made her a Grand Dame in 2005.

“The Italian comes to his table with the same open heart with which a child falls into his mother’s arms,” Mrs. Hazan wrote in her first cookbook, “with the same easy feeling of being in the right place.”