Browsing by Author "Enroth, Nina"

Producer has to determine a shelf-life to the product. This can be a slow process, as it is in the case of chocolate. With an accelerated shelf-life study, the product gets older faster, as the properties of the product change faster during storage. This leads to a quicker shelf-life determination. Chocolate has properties, which are typical for it. However, these properties can change during the storage. Good sensory properties are important to the quality of chocolate. Changes in sensory properties limit the shelf life of chocolate. It is said that, the most important properties of chocolate are appearance, flavour and texture. Other properties can have an impact on how other properties are sensed. For example, chocolate’s viscosity and how it melts, can affect to the flavour. The aim of this study was to develop a method, which could observe changes in the properties of dark chocolate faster. In this study, especially the changes of the added aroma during the storage, were monitored. Dark chocolate and dark chocolate with aroma were stored at elevated temperatures to accelerate changes. Storage time was 9 weeks, and during it the hardness of the chocolate was monitored with a texture analyser. Melting points of the chocolate were followed with a differential scanning calorimeter. Blooming was monitored with a DigiEye-equipment. With gas chromatographic-mass spectrometric-solid phase micro extraction (HS-SPME-GCMS) the amounts of volatile flavour components of the aroma were studied. Sensory properties of chocolates were studied in three sensory analyse sessions using multiple comparison test. The properties of chocolates, which were stored at elevated temperatures, changed during the 9-week storage. Structure became harder and melting temperature became higher. Some of the chocolates bloomed. In the amount of aroma volatiles, no clear changes were observed. From the results of the sensory analyses it was noticed that storage at elevated temperatures clearly changed the properties of the chocolates. However, when changes were examined with statistical analyses, all of these were not statistically significant. The properties of the samples were noticed to have correlations with other properties and the storage time.