| Chocolate is highly susceptible to bloom, a dull, white-gray haze of fat or sugar that forms on the chocolate surface. Bloom is caused by a number of factors including composition and processing and storage conditions. Although bloomed chocolate is safe to consume, it is unappealing and unsalable, making it an ongoing concern for chocolate and confectionery manufacturers.;The phenomenon of chocolate bloom has been studied for decades, and in 1925, it was shown that nut – containing chocolates bloom faster than plain chocolates. Research over the years has led to current theories suggesting phase transitions and lipid migration from nuts and fillings are leading causes of bloom in nut-containing chocolates. However, few studies have focused on interactions between whole nuts and milk chocolate, and the impact of nut roasting and pasteurization treatments on bloom and lipid migration. This thesis aims to elucidate the causes that lead to surface bloom on milk chocolate bars around whole almonds, with a focus on lipid migration, through the use of storage studies and a number of analytical techniques. Changes in melting properties due to lipid migration between almonds and chocolate were studied via differential scanning calorimetry (DSC). Tocopherol analysis was done by high performance liquid chromatography (HPLC) and fatty acid analysis was performed by gas chromatography-mass spectrometry (GC-MS). Changes in tocopherol and fatty acid composition of chocolate samples with and without treated almonds were observed, and provided insight into interactions that occurred between chocolate and whole, treated almonds. |
