Processed Pulp Recovery Rate and Percent Seed Contained In Five North American Pawpaw Cultivars

The North American pawpaw (Asimina triloba) is the largest tree fruit indigenous to the United States and is being grown on a small scale commercially. Pawpaws produce a unique fruit with a creamy yellow-orange flesh and a mango/banana-like flavor. Interest is growing in pawpaw as an alternative fruit crop. The fruit’s short shelf life and difficulty with postharvest handling and storage present an impediment to further commercial development. Marketing the frozen fruit pulp as a value-added product is one solution to this problem. However, pawpaw fruit pulp extraction is labor-intensive and made difficult by the row of large inedible seeds contained in the fruit, and valuable pulp may be lost through ineffective extraction methods. The objective of this study was to determine if processed pulp recovery rate differs by pawpaw cultivar. Three sets of five ripe fruit of five commonly available pawpaw cultivars (KSU-Atwood, Mitchell, PA-Golden, Sunflower, and Susquehanna) were selected.  These cultivars were selected based on varietal fruit size, with Mitchell and PA-Golden being small fruited cultivars, and texture differences that were previously observed; Susquehanna tends to have a firm flesh and PA-Golden has soft flesh. The fruit were cut in half and pulp and seed were removed with a spoon and processed using a modified Roma Sauce Maker to separate seeds from pulp and macerate the pulp. The pulp/seed mixture was run through the strainer 3 times to obtain as much processed pulp as possible. Individual fruit weights and seed weights were measured on fifteen fruit each of the five cultivars by weighing whole fruit, removing the seeds, and measuring the weights of clean seeds. Processed pulp recovery rate varied significantly among cultivars, with Susquehanna (44%), KSU-Atwood (41%), and Sunflower (41%) having a greater percentage of pulp recovered from fruit compared to Mitchell (24%); PA-Golden (33%) was not statistically different from either group. Susquehanna (230 g), KSU-Atwood (182 g), and Sunflower (204 g) had higher fruit weights than PA-Golden (132 g) or Mitchell (62 g). A positive correlation was found between fruit weight and percent pulp recovered (r=0.73). Larger-fruited cultivars had a lower percentage of seed, with Susquehanna (4%), KSU-Atwood, Sunflower, and PA-Golden (all 8%) having less seed by weight than Mitchell (13%). With large fruit weights, a high rate of processed pulp recovery, and a high fruit:seed ratio which enables more efficient processing, the cultivars KSU-Atwood, Susquehanna, and Sunflower are good choices for pawpaw growers and processors.