Comparison of microbial recovery methods and sanitation treatments on microbial load and quality of blueberries
Melody Corbitt, Juan L. Silva, Frank B. Matta and Diane K. Tidwell
Thesis, Master of Science (Nutrition), Mississippi State University. 2010.
2010
บทคัดย่อ
Microbial recovery methods for frozen blueberries, and postharvestsanitation treatments on microbial load and sensory attributes of berries were studied. Previously frozen rabbiteye blueberries were subjected to hand-mixing, machine-mixing, stomaching, vortexing, and homogenization. Aerobic (APC) and yeast and mold (YMC) counts did not differ amongst treatments but homogenization, stomaching, and vortexing tended to yield a higher recovery, with vortexing resulting in the choice method for YMC possibly due to cell disruption and colony breakage. Fresh highbush blueberries were treated with hot water (60 - 90°C) with an oxidizing agent (0 - 0.1% Boxyl®) for 10 - 30s. Water temperature was the most influential (p<0.05) factor on microbial reduction, wax/bloom and color. Holding berries at 75°C for 20s (without antimicrobial) or dipping in 200ppm chlorine for 10s resulted in 0.90 and 1.80 log reduction of APC and yeast, respectively; and 0.80 (200ppm/10s) and 2.90 (75°C/20s hot water) log reduction in mold counts.