Shrinkage and Density Change of De-Boned Chicken Breast during Deep-Fat Frying

Abstract

The effects of frying oil temperature (FOT) and time on densities and shrinkage in chicken breast meat during deep-fat frying were investigated. De-boned Chicken breast samples were diced and fried at different FOT (170℃, 180℃, and 190℃) in an industrial fryer for periods varying from 5 to 900 s. Bulk and apparent densities were determined with a fluid displacement pycnometer, and fat analysis was conducted using soxhlet extraction with petroleum ether solvent. The physical structure of chicken meat changed significantly with the frying time and FOT (P < 0.001). Bulk density was 1.15 g/cm 3 in the raw product and decreased to 0.98, 0.95, and 0.93 g/cm 3 after 900 s of deep-frying at 170℃, 180℃ and 190℃, respectively. Similarly, apparent density changed from 1.13 to 1.25, 1.24 and 1.22 g/cm 3 and moisture loss was linearly correlated with both densities. Volumetric shrinkage was significantly (P < 0.05) affected by the process variables and hence a linear correlation also existed with moisture loss. The rates of shrinkage were 0.013, 0.001, and 0.008/s and occurred rapidly during the first 90s of FOT (170℃, 180℃, and 190℃), respectively and decreased as frying time increased.