100-2 |
Instrumental textural analysis of Alaskan pollock |
J. N. TALBERT, Gorton's, 303 Main St., Gloucester, MA 01930 and J. Hirsch. Currently, reliable determination of textural properties of whole fillets and frozen prepared fish products exists only through sensory panels. Alaskan pollock, widely used in frozen seafood, is processed as single-frozen (caught, filleted and frozen within 3 hours of catch) or twice-frozen fillets (fish are caught, headed and gutted, then frozen until filleted). It is well established that twice-frozen fillets are tougher than single-frozen. Similarly, different breadcrumbs can make frozen fish seem crunchier. This research was designed to determine whether the TAXT2i Texture Analyzer could quantify known textural fish attributes. The objectives of this study were to 1) quantify textural differences between thawed single and twice frozen Alaskan Pollock fillets and 2) quantify ‘hardness’ of 2 different breadings on fillets, using the TAXT2i Texture Analyzer. Non-destructive compression tests (using a stainless steel ball probe, AOAC plastic cylinder, or knife blade, 2mm into fish) and a destructive shear test (using the Warner Bratzler blade) were conducted using the TAXT2i Texture Analyzer. Tests were performed 3” from thawed whole fillet tail end and center of breaded fillet. Probe speed was 5mm/s. Multiple measurements were performed at room temperature. Peak values of force time curves (measurement of toughness) for both compression (279.2g and 239.3g) and shear (6836.9g and 8250.4g) were not statistically different (p<0.05) for single and twice-frozen thawed fillets, respectively. Similarly, there was no statistical difference (p<0.05) in peak values for compression (hardness measurement) (1136.5g, 1156.1g) or shear force (1254.0g, 1245.7g) between fillets prepared with two different breadcrumbs. In these experiments, the TAXT2i Texture Analyzer could not quantify textural differences between thawed single and twice-frozen Alaskan pollock fillets, or between the two different breadings on fish. Due to high variability between natural fillets, we have not yet found an instrument that quantifies fish textures as reliably as sensory methods.
Session 100, Seafood Technology: Texture, Chemistry
|