# Characterization of Thermal Properties of Ruby Chocolate Using DSC, PDSC and TGA Methods
## 1 Introduction  
The chocolate industry is one of the most prosperous branches of the food industry. Chocolate consumption and competition in its production process increase year by year. There is also a growing public awareness about the quality of chocolate. Customers have a large choice of products, but they are used to a few basic types of chocolate, i.e., milk, dark and white [1].  
The appearance of RC in stores has aroused widespread curiosity. [PERSON] has patented [2] the production process of a new type of chocolate with a specific color and fruit flavor. Emerging news in the media suggested a new variety of cocoa beans from which ruby chocolate was produced. However, there is no scientific confirmation for the existence of a new variety of cocoa beans. Traditionally, chocolate is made from fermented, roasted cocoa beans.  
What happens during fermentation is still not entirely clear. There are two main methods of fermentation: beans are either placed in piles and covered with banana leaves, or placed in wooden boxes with holes or slits. The process in both cases takes from 5-6 days, and the length is actualized according to experience [3]. The fermentation and subsequent roasting are used to change the taste of the cocoa beans, to protect the beans microbiologically and also to change the color of naturally purple beans. All types of chocolate are produced from the beans of the same plant, _Theobroma cacao_ L. species; types of chocolate may differ, among other aspects, in appearance, bitterness and the composition of fatty acids. Ruby chocolate is made from beans that have either not been fermented orin which the fermentation process has been significantly reduced [2]. For this reason, the beans retain their natural pink color.  
The producer uses organic or inorganic acid to maintain the color and appropriate acidity. However, the detailed procedure remains the manufacturer's secret. Regardless of the type of chocolate, similar attributes drive consumers' interest.  
The color of RC and its taste, which is very different from that of traditional chocolate, can distract customers from other important indicators of chocolate quality, such as the composition of fatty acids or the melting temperature [4]. The elimination of fermentation and roasting provides a simpler infrastructure and reduces the cost of obtaining the raw material. Additionally, the general features that define a good quality of cocoa can be ignored because they are, in any event, imperceptible in RC. Hence, RC is expected to have slightly different structure and thermal properties. Each type of chocolate, especially milk chocolate, contains a very complex mixture of ingredients [5]. Based on the list of ingredients, the qualities of RC should be closer to those of the milk chocolate category than to those of dark chocolate.  
Therefore, thermal techniques, such as DSC and TGA, are highly recommended during RC analysis and they have many advantages over traditional analysis. DSC can provide information about processes such as crystallization and oxidative stability by applying isothermal or non-isothermal conditions, respectively [6; 7; 8]. TGA indicates which endothermic event corresponds to mass loss. TGA has been successfully used to determine the composition of dark and milk chocolate and consequently to control the quality of that product [9; 10].  
The purpose of this work was to use TGA to determine the composition of RC, as well as to use DSC and PDSC to both characterize the melting profile and to measure the oxidative stability of the fat extracted from RC.