36E-66

M. E. COREY¹, R. B. Beelman, and K. Seetharaman. (1) Dept. of Food Science, The Pennsylvania State Univ., 111 Borland Laboratory, State College, PA 16802-2504

Off-grade white button (Agaricus bisporus) mushrooms that do not meet retail quality specifications for the fresh market are often canned or used for other means. However, they have potential for use as a value-added functional food ingredient. The objective of this study was to determine physical and chemical properties of white button mushroom powders for potential application in foods as a functional ingredient. Raw and blanched mushrooms (blanched in boiling water for 5 min) were used in this study. The mushroom samples were freeze-dried and ground prior to testing. They were analyzed for their bulk density, water-holding capacity (WHC) at 20° C, water-swelling capacity (WSC) at 60° C, and for their thermal and viscosity properties. The WHC, WSC, and bulk density for raw mushroom powders was 3.61 ml/g, 6.39 g/g and 8.89×10^-2 g/cm³, respectively. Alternately, blanched mushroom powders had a slightly lower WHC (3.39 ml/g), WSC (5.90 g/g), and significantly higher bulk density (0.187 g/cm³) than raw mushroom powders. The materials exhibited shear-thinning behavior when subjected to constant shear rate at 20° C, 40° C, 70° C, or 80° C. Raw mushroom powder had an initial viscosity about 700 cP, but showed a constant decrease in viscosity above 60° C. A significantly lower initial viscosity (about 100 cP) was observed for blanched mushroom powder, except a substantial increase in viscosity was observed at elevated temperatures (90-95° C). Thermal analysis conducted by using a DSC showed a broad endothermic phase transition. The transition temperature decreased to lower temperatures with increasing water activity. Similar results were observed for both raw and blanched mushroom powders. Physico-chemical characterization of the mushroom powders indicated that they could have novel applications as functional ingredients in foods.

Session 36E, Fruit & Vegetable Products: General
8:30 AM - 12:00 PM, Monday AM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana