A puree-making process has gone international with patents issued in the United States and now also in China, New Zealand and Australia. The award-winning process was jointly patented by collaborators with the U.S. Department of Agriculture (USDA), North Carolina State University (NC State) in Raleigh, and Industrial Microwave Systems, L.L.C., in Morrisville, N.C.
The microwave processing method and a shelf-stable packaging system provide purees used by manufacturers as well as commercial buyers and other customers. The purees are used in a variety of finished food products such as cookies, pies, ice cream, baby foods, soups, sides, beverages and frozen foods.
Originally licensed for making and packaging nutritious sweetpotato puree, the unique process is now being used to make pumpkin, butternut squash, broccoli, carrot and spinach purees as well. When naturally sweet vegetable purees are used in baked goods as a “replacer,” for example, manufacturers can cut back on sugars, fats and oils, which are more expensive and less nutritious. A variety of foodservice operators, restaurants and bakeries also use the purees.
USDA food scientist Van-Den Truong and his collaborators tested the technology extensively at an NC State pilot plant. Truong works at the Agricultural Research Service (ARS) Food Science Research Unit in Raleigh, NC. ARS is USDA’s chief intramural scientific research agency, and this research supports the USDA goal of promoting international food security. Truong’s collaborators include NC State food engineers Josip Simunovic, Gary Cartwright, K.P. Sandeep, and Ken Swartzel, and former graduate students Pablo Coronel, Prabhat Kumar and Laurie Steed.
Truong and his colleagues also have converted purple-fleshed sweetpotatoes into shelf-stable purees for food applications. They measured the levels of bioactive phytochemicals called anthocyanins in purple-fleshed sweetpotatoes and found the levels comparable to those in commodities such as grapes, plums, sweet cherries, eggplant and red radishes. They also measured phytochemical retention before and after processing purple-fleshed sweetpotatoes into puree, and found good phytochemical retention.
Read more about this research in the February 2014 issue of Agricultural Research magazine.