HYDRO-DENSITY SORTING OF RABBITEYE BLUEBERRY FRUIT (VACCINIUM ASHEI READE)
Mechanical harvesting of blueberry for the fresh market necessitates the need for a rapid, quality-based method for sorting fruit. Machine harvested rabbiteye fruit were separated into 4 bulk density classes based on sink/float determination in 2%, 4% and 6% NaCl brines. Each density class was evaluated for color, size, sugars, organic acids and firmness. Berry density was directly related to weight (r=0.57), soluble solids (r=0.79) and inversely related to firmness (r=0.61). A 4% solution removed all green, 90% of red fruit and 10–20% of blue fruit. Fruit sinking in 6% brine were overmature and usually mechanically damaged. Plot vigor or year of harvest did not affect the ability of density sorting to separate out fruit of different internal qualities. Quinic acid was the predominant acid and fructose and glucose the major sugars present at all berry densities. Hydro-density sorting techniques may be suitable to grade blueberry fruit into several quality classes based on their degree of ripeness and internal quality.
Patten, K., Scheuerman, M.R. and Burns, E.E. (1989). HYDRO-DENSITY SORTING OF RABBITEYE BLUEBERRY FRUIT (VACCINIUM ASHEI READE). Acta Hortic. 241, 354-359