Microstructure and mechanical properties related to particle size distribution and composition in dark chocolate
Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Josélio Vieira
International Journal of Food Science & Technology
Abstract
Summary Composition in dark chocolate was varied and the effects determined on microstructure, using light microscopy, and mechanical properties of molten and tempered chocolates, using a TA.HD Plus Texture Analyser. Compositional parameters were particle size distribution (PSD) (D 90 of 18, 25, 35 and 50 μm), fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%) contents. Micrographs revealed wide variations in sugar crystalline network structure and inter‐particle interaction strengths related to PSD and fat level. Samples containing 25% fat had more crystal agglomerates, well flocculated with greater particle‐to‐particle interaction strengths than those with higher (30% and 35%) fat contents. Increasing the D 90 to 35–50 μm caused broadening of the PSD, with particles becoming coarser, which were similar at all fat levels. Mechanical analysis showed that PSD, fat and lecithin content significantly influenced firmness of molten chocolate and hardness of solid (tempered) chocolate with significant interactions among factors. Particle size was inversely correlated with firmness (1235–173 g) and hardness (7062–5546 g). Greatest effect of PSD was with 25% fat and 0.3% lecithin. With higher fat and lecithin contents, the PSD influence was reduced. It was concluded that PSD, fat and lecithin contents and their interactions were central to mechanical properties of dark chocolates.
Extracted Claims
9 claims extracted from this paper into the knowledge graph
PSD, fat, and lecithin content significantly influence firmness of molten chocolate and hardness of solid (tempered) chocolate
“Mechanical analysis showed that PSD, fat and lecithin content significantly influenced firmness of molten chocolate and hardness of solid (tempered) chocolate with significant interactions among facto...”
30% and 35% fat results in less crystal agglomerates and weaker particle-to-particle interaction strengths
“Samples containing 25% fat had more crystal agglomerates, well flocculated with greater particle‐to‐particle interaction strengths than those with higher (30% and 35%) fat contents.”
particle size is inversely correlated with firmness and hardness
“Particle size was inversely correlated with firmness (1235–173 g) and hardness (7062–5546 g).”