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doi:10.1016/j.foodchem.2006.02.031
Copyright © 2006 Elsevier Ltd All rights
reserved.
Functionality of fruit powders in extruded
corn breakfast cereals
Mary Ellen Camire
a, 
, 
, Michael P. Doughertya and Jack L. Briggsb
aUniversity of Maine,
Department of Food Science and Human Nutrition, 5735 Hitchner Hall, Orono, ME
04469-5735, USA
bNatick Soldier Center,
Natick, MA 01760, USA
Received 26 October 2005; revised 10 February 2006; accepted 22
February 2006. Available online 3 April 2006.
Abstract
Consumer interest in naturally colored foods such as
breakfast cereals is growing. Degermed white cornmeal, sucrose, citric acid and dehydrated fruit powder
(blueberry, cranberry, Concord grape and raspberry) were mixed in
84.3%:14.3%:0.4%:1.0% proportions, then extruded in a laboratory-scale
twin-screw extruder. Feed rate was 255 g/min; water was pumped at a rate
of 12.5 g/min; screw speed was 175 rpm. Cooking temperature during
extrusion was generally <130 °C. Samples were cut into small spheres
and dried to 5% moisture. Cereals were stored at room temperature in opaque
bags. The control samples were lighter and less red than the fruit cereals.
Soluble phenolics and anthocyanins were higher in the fruit cereals. At three
and six weeks of storage, fruit cereals had smaller levels of hexanal, as
measured by gas chromatography of headspace of ground cereals. Although
anthocyanins from fruit powders survive extrusion and retain some antioxidant
activity, the levels used in this study may have been too low. Higher levels of
fruit will increase production costs, but the expense may be offset by the more
attractive and functional cereals that result.
Keywords: Extrusion;
Anthocyanin; Antioxidant activity; Fruit
Corresponding author. Tel.: +1 207 581 1627; fax: +1 207
581 1636.