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Relationship Between Rheological, Textural And Melting Properties Of Dark Chocolate As Infuenced By Particle Size Distribution And Composition, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira
Relationship Between Rheological, Textural And Melting Properties Of Dark Chocolate As Infuenced By Particle Size Distribution And Composition, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira
Professor Emmanuel Ohene Afoakwa
In dark chocolate, rheological properties during processing are influenced by particle size distribution (PSD), fat and lecithin contents with consequential effects on finished texture and melting characteristics. Multivariate regression, correlation and principal component analyses (PCA) were used to explore their interrelationships. A 4 x 3 x 2 factorial experiment was conducted with varying PSD [D90 (90% finer than this size) of 18ìm, 25ìm, 35ìm and 50ìm), fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%). Rheological properties (yield stress and apparent viscosity), textural properties (firmness, index of viscosity and hardness) and melting index (duration) were respectively measured using shear …
Particle Size Distribution And Compositional Effects On Textural Properties And Appearance Of Dark Chocolates, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira
Particle Size Distribution And Compositional Effects On Textural Properties And Appearance Of Dark Chocolates, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira
Professor Emmanuel Ohene Afoakwa
Particle size distribution (PSD) and composition in dark chocolate were varied and their effects on textural properties of molten and tempered chocolates determined using a TA.HD Plus Texture Analyzer. Surface colour was evaluated in terms of CIELAB parameters L*, C* and h° using a HunterLab Miniscan Colorimeter. Compositional parameters for particle size distribution were [D90 (>90% finer) of 18 ìm, 25 ìm, 35 ìm and 50 ìm], fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%) contents. Results showed that PSD, fat and lecithin content significantly (p<0.05) influenced the textural parameters with significant interactions among factors. Particle size was inversely correlated with firmness (1235 - 173 g), consistency (50410 - 7029 g.s), cohesiveness (1594 - 262 g), index of viscosity (5737 - 1099 g.s) and hardness (7062 - 5546 g) with chocolates containing 25% fat and 0.3% lecithin. With higher fat and lecithin contents, PSD influence was reduced. PSD and fat concentration inversely influenced all colour measurements (L*, C* and h°) of samples. High correlations (r = 0.71 – 1.00, P<0.001) were observed between texture parameters and colour. It was concluded that PSD, fat and lecithin contents and their interactions were central to changes in textural properties and appearance during processing of dark chocolates.