Functional Properties of Breadfruit Flour and Its Application in Processed Meat
The compositional and functional properties of breadfruit flour and comminuted beef/beef emulsions prepared with breadfruit flour were studied. The breadfruit flour was compared with traditional flour sources (wheat, soy, corn, tapioca) and a tropical flour source (banana). Native breadfruit flour had high content of starch (66.59% - 73.39% on a dry-matter basis) and greater water/oil holding capacity than traditional flour sources, yet was similar in those traits when compared with banana flour. Native breadfruit flour had high viscosity during heating. Cooking loss was reduced in beef emulsions prepared with breadfruit flour compared with control (no flour added) samples, and decreased as flour inclusion level increased. Hardness (measured with texture profile analysis) was lower in beef emulsions prepared with breadfruit flour compared with those prepared with wheat, corn, and tapioca flour, and decreased as flour inclusion level increased. Instrumental redness of comminuted beef prepared with breadfruit flour was the greatest during a 7-day simulated retail display compared with traditional flour sources and control samples, and increased as flour inclusion level increased. The pasting temperature of unmodified breadfruit flour was approximately 77°C. Breadfruit starch did not completely gelatinize after cooking (72°C) and was not fully functionalized in comminuted meat. This led to research on pre-gelatinization of breadfruit flour. Breadfruit flour was extruded using different conditions which included last barrel temperature (80°C or 120°C) and feed moisture content (17% or 30%). Four extruded flours with different mechanical (specific mechanical energy, SME) and thermal (melt temperature) energies were obtained. Swelling power was increased in all extruded treatments at temperatures below gelatinization of the native starch (<70°C), while water holding capacity and solubility were dramatically increased in the low-SME and high-SME extruded flours, respectively. Addition of extruded flours did not change cooking loss, instrumental redness, and viscoelasticity of cooked meat emulsions compared with native flour and control samples. Extrusion conditions, particularly those with high thermal energy, altered hardness of meat emulsions. Incorporation of extruded breadfruit flours can modify the structural and technological attributes of beef emulsions compared with native flour, but technological function of beef emulsions formulated with different extruded flours were not different.