Effect of Extrusion and Steam Pressure on Fiber and Nutritional Properties of Pineapple Peels
Zuwariah Ishak *
Food Science and Technology Research Centre, MARDI HQ, 43400 Serdang, Selangor, Malaysia.
Noor Fadilah Mohd Bakri
Food Science and Technology Research Centre, MARDI HQ, 43400 Serdang, Selangor, Malaysia.
Syahida Maarof
Food Science and Technology Research Centre, MARDI HQ, 43400 Serdang, Selangor, Malaysia.
Hadijah Hassan
Food Science and Technology Research Centre, MARDI HQ, 43400 Serdang, Selangor, Malaysia.
Rodhiah Razali
Food Science and Technology Research Centre, MARDI HQ, 43400 Serdang, Selangor, Malaysia.
Mohd Fakhri Hashim
Food Science and Technology Research Centre, MARDI HQ, 43400 Serdang, Selangor, Malaysia.
*Author to whom correspondence should be addressed.
Abstract
Research finding on modification of pineapple peel through extrusion and steam pressure have led to increasing fiber and nutritional properties of the pineapple powder. The objective of the present study was to investigate the effect of extrusion processing and steam pressure on soluble and insoluble fiber contents, antioxidant activities, sugar profile and proximate contents. The extrusion of Morris pineapple peel increased soluble dietary fiber (SDF-2.8 folds), insoluble dietary fiber (IDF-1.2 folds) and total dietary fiber (TDF-1.3 folds). Steam pressure treatment also show the same trends of fiber modification in Morris peel (SDF-3.4 folds, IDF-1 folds, TDF-1.2 folds). The sugar profile showed that fructose and glucose increased after fiber modification. Total phenolic content (TPC), ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH test) had been used to determine antioxidant activity in both processing method. The results of the proximate analysis showed that protein, crude fiber and moisture content affected by extrusion and steam pressure process of pineapple peel. It can be conclude that modification of fiber through extrusion and steam pressure is able to alter fiber and nutritional properties of pineapple peel.
Keywords: Fiber, extrusion, steam pressure, antioxidants, sugar, proximate