DIETARY FIBER CONTENT OF PEAR AND KIWI POMACES

Pear and kiwi pomaces, edible byproducts from single-pass metallic mem brane ultrafiltration of pear and kiwi purees, were studied for compos ition and utilization as sources of sugar and dietary fiber in food te chnology. This paper describes the total (TDF), soluble (SDF), and ins oluble (IDF) dietary fiber content of pear and kiwi pomaces determined according to the AOAC gravimetric method. In addition, fiber values w ere determined by measuring the levels of the composite sugars by colo rimetric and GLC methods and Klason lignin. On a dry weight basis, the TDF content of pear pomace was 43.9%, while that of kiwi pomace was 2 5.8%. In both pomaces, the SDF was pectic in origin and contributed ap proximately 7% dry weight, while IDF measured 36.3% in pear and 18.7% in kiwi. Lignin content, estimated gravimetrically, was 5.2% and 3.2% dry weight for pear and kiwi pomaces, respectively. Protopectins and h igh methoxyl pectins were the main type of pectic substances for IDF a nd SDF, respectively, in both pomaces.