Mechanical and chemical properties of Gold cultivar pineapple flesh (Ananas comosus)

Abstract

Pineapple flesh cut from three cross sections along the central axis were used to determine mechanical response to compression, penetration, shear and extrusion forces, color and related enzymes activity, antioxidant properties and other quality attributes and how they vary along the central axis of the fruit to determine the key factors to define Gold cultivar pineapple quality requirements for fresh-cut processing. Hardness, fracturability and associated work did not significantly vary among fruit pieces from different sections of the fruit, except for shear hardness (from 6.5 ± 1.2 to 10.0 ± 3.5 N) and related work (from 19 ± 6 to 41 ± 24 N mm). Color parameters, L*and b*, increased from the bottom to the upper third, while a* and POD activity (6.70 ± 0.15 to 6.02 ± 0.11/min/mL) significantly decreased while PPO activity was not detected. Vitamin C and total phenol content to acidity ratio were lower in the upper third of the fruit (305 ± 40 mg/100 gfw and 40.3 ± 1.0 mg gallic acid/100 gfw, respectively), contrary to titratable acidity (0.45 ± 0.05 to 0.70 ± 0.05 g/100 gfw) and water content (81.2 ± 0.8 to 85.7 ± 1.4%). POD activity, water content, total phenolic compounds and the ratio soluble solids to acidity were the four parameters which allowed better discrimination between Gold cultivar pineapple flesh cut from the three cross sections along the central axis of the fruit and showed the highest correlation coefficients between each pair of parameters.