NEAR INFRARED SPECTROSCOPY MEASUREMENT AND KINETIC MODELING FOR PHYSIOCHEMICAL PROPERTIES OF TABTIM FISH (HYBRID TILAPIA OREOCHROMIS SP.) FILLETS DURING CHILLING STORAGE

Abstract

This research is aimed to investigate the physiochemical properties of Tabtim fish fillets [pH, moisture content, water holding capacity (WHC) and texture profile analysis] during storage at 0, 5, and 10ºC for up to 18 days. Near infrared spectroscopy (NIR) was used as a nondestructive measurement and kinetics was also applied for determining the quality changes. Results showed that the pH value increased with an increase of storage time and storage temperature (P≤0.05) while the hardness and WHC were decreased as a result of increasing time and storage temperature (P≤0.05). Change in pH, hardness, gumminess, and chewiness during storage can be described by zero- or first-order reactions. NIR spectra of fish fillets (180 samples) were collected in the reflectance mode with both the short-wavelength region (700-1000 nm) and long-wavelength region (1000-2500 nm). A partial regression model with cross validation was created. The models for pH, hardness, adhesiveness, and gumminess demonstrated that the value for the determination coefficient of validation ranged from 0.61-0.73 while the standard error of prediction was 0.14 for pH, 2.58 N for hardness, 0.21 N.mm for adhesiveness, and 1.68 N for gumminess. The model developed using NIR could predict pH, hardness, adhesiveness, and gumminess as basic for a screening test.