Purdue News

February 1994 Pawpaws Provide Potential, Purdue Professors Predict WEST LAFAYETTE, Ind. – The pawpaw – the largest fruit native to the United States – has the potential to become a popular flavor in American foods, says a Purdue University flavor chemist. Hoping that the prediction is accurate, in early March a Purdue horticulturist and researchers at 13 other universities will plant pawpaw groves to determine the best varieties of this unusual fruit. Carol Karahadian, a food chemist in Purdue's Department of Foods and Nutrition, says that because of its unique taste, the pawpaw could become the next trendy fruit, like the kiwi. "You can cut a pawpaw open and the whole room is filled with this wonderful fruity aroma," she says. "It has a strong tropical flavor." Bruce Bordelon, assistant professor of horticulture and coordinator of Purdue's pawpaw variety trial, says, "Pawpaws are shaking out as having good market potential already. They should start showing up soon in expensive restaurants as a novelty item." The pawpaw (Asimina tiloba) was a popular fruit in the United States in the 19th century and early in the 20th century. The yellow-brown fruits are about the size of a potato with a texture like a very ripe banana on the inside. Although Karahadian can catalog the chemical compounds that give the fruit its aroma and flavor, when describing the fruit she relies on comparisons to more familiar flavors. "The taste is reminiscent of papaya with pineapple overtones, with bits of banana and mango," she says. "It has a very sweet, pleasant tropical-fruit flavor without being exactly like any of these fruits. It's a rich fruit. You really can't eat more than one." However, she cautions that even if consumers are willing to accept the strong new taste of pawpaw, problems with the fruits themselves could limit their widespread use. At this point, Karahadian foresees pawpaws being used as a food ingredient, rather than as a raw food. "It's really kind of a strange fruit," she says. "It's not a fruit that you can just cut out the core and hand it to your kid." One of the difficulties with pawpaws is that they self-destruct just as they are the tastiest. "The intensity of fruitiness peaks at ripeness, and the fruits fall off the tree immediately after," Karahadian says. "Then they become quite a mess." The fruits do ripen off the tree, but because pawpaws ripen fast and bruise easily, they're almost impossible to get to market in a usable form. "By the time they'd make it they'd be soup," Karahadian says. Karahadian is conducting research to determine the optimal time to harvest the fruit. Modified atmosphere packaging could give shippers more time to get the fruits to market, she says. Pawpaws are native to 21 states in the eastern United States, although they are most commonly found in Indiana, Ohio, Illinois and Michigan. In Indiana they are known as the "Indiana Banana," although at least one other state, Michigan, also makes claim to the banana name (with substantially less alliterative success). Michigan even boasts a town with the name "Paw Paw." Pawpaws are the only members of the tropical custard apple family to grow in temperate regions. "They're considered a tropical fruit, but this ain't the tropics," Karahadian says. In fact, hardiness is one attractive characteristic of the pawpaw, which survives to 30 degrees below zero. The 14-university research project plans to discover the optimal environment for pawpaws, the best methods of growing them and which pawpaws hold the most potential for commercial success. Within the next few weeks Purdue will begin planting 280 pawpaws, seven each of 40 different varieties, as a part of the study. This is in addition to the 275-tree grove already growing at he Purdue Horticulture Research Center. The nearly 600 pawpaw trees will make Purdue's one of the largest pawpaw patches in existence. The research projects are being conducted under the guidance of Purdue's New Crops Center. Bordelon has been growing pawpaws for the past few years not for their fruit, but for their bark. He is looking to a future market for pawpaw bark and twigs based on the research of Jerry McLaughlin, professor of medicinal chemistry and pharmacognosy at Purdue, who has found a compound in the bark of the trees called "asimicin" that has shown preliminary success as a botanical pesticide. This compound also has shown some anti-cancer properties, an area that is being explored by pharmaceutical companies. According to Karahadian, genetic engineering could solve a lot of the pawpaws' problems. "But before scientists are willing to do the research, somebody must show a great need for improved pawpaws," she says. "In the future we'll conduct consumer testing. It's important to find out what the market thinks."   NOTE: The other universities involved in the research project mentioned in this story are University of Arkansas, Auburn University, Clemson University, Cornell University, the University of Georgia, Kentucky State University, Louisiana State University, Michigan State University, the University of Nebraska, North Carolina State University, Ohio State University, Oregon State University and West Virginia University. Purdue News Service: (765) 494-2096; purduenews@purdue.edu