New Jersey Agricultural Experiment Station publication No D-10535-1-89, supported by State funds and the Center for Advanced Food Technology. The Center for Advanced Food Technology is a New Jersey Commission on Science and Technology Center. The technical help of Kiran Shah on particle density and size measurement is acknowledged.
Density and Porosity in Drying Starch Materials
Version of Record online: 25 AUG 2006
Journal of Food Science
Volume 55, Issue 5, pages 1367–1372, September 1990
How to Cite
MAROUSIS, S.N. and SARAVACOS, G.D. (1990), Density and Porosity in Drying Starch Materials. Journal of Food Science, 55: 1367–1372. doi: 10.1111/j.1365-2621.1990.tb03939.x
- Issue online: 25 AUG 2006
- Version of Record online: 25 AUG 2006
- Ms received 6/9/89; revised 10/20/89; accepted 11/21/89.
The particle density of granular and gelatinized corn starches was determined in the moisture range 0 to 1 kg water/kg dry solids, using a gas stereopycnometer. The bulk porosity (void fraction) of spherical starch samples at various moisture contents was estimated from the bulk and particle densities during air drying at 60°C. The particle density data fitted a polynomial function of moisture content (X), passing through a maximum value of 1500 kg/m3 at X = 0.15. The bulk porosity of the starch samples increased linearly during drying, reaching a value of 0.45 near dryness. Differences in structure between granular and gelatinized starches during drying were observed by stereomicroscopy. The changes in porosity could be related to variations of the effective moisture and thermal diffusivities of starch materials.