Chocolate aroma: Factors, importance and analysis

Highlights

• Flavor has an important role in the unique taste of chocolate.

• Fermentation, drying and roasting in cocoa processing have a great influence.

• Chocolate mass production may affect in formation and removing of some aromatic compounds.

Abstract

Background

The quality and value of chocolate are related to its unique and fascinating flavor arisen from volatile and non-volatile compounds present in the product. The particular chocolate aroma is dependent on various factors including genotype and the agro-ecological niche (environment conditions, farming practices), post-harvest conditions and complex biochemical and chemical reactions during this period (fermentation, drying) and manufacturing stages.

Scope and approach

In this study, relationship between chemical compounds and cocoa flavors, control and management of post-harvest practices and manufacturing processing in order to obtain chocolate with differentiated characteristics and also evaluation methods especially sensory aspects of the chocolate are highlighted. For this purpose, instrumental experiments including headspace aroma extraction, simultaneous distillation extraction and sensory testing such as discrimination experiments, descriptive tests and hedonic experiments were discussed.

Key findings and conclusions

A comprehensive link between the components of cocoa flavor, sensory characteristics, human acceptability, and also the processes involved in flavor formation and formulation used, will assist the administration of a traceability system, a challenging case for quality assurance groups.

Introduction

Chocolate as one of the most popular foods is consumed by people of all ages. Higher consumption of chocolate was associated with significantly higher antioxidant properties, which have beneficial impact on human health (Aktar, Chen, Ettelaie, Holmes, & Henson, 2017). Unique sensory experience that chocolate creates is related with the melting profile in the mouth as well as specific odor and taste (aroma properties). For chocolate aroma, the cocoa present in the formulation and production process is very important for manufacturing the product with desired quality characteristics (Braga et al., 2018). The factors that are responsible for the aroma development in cocoa beans and chocolate are, cocoa cultivation (genetic origin, climatic conditions), post-harvest treatments (including fermentation and drying stages), chocolate processing (roasting and conching) (Da Veiga Moreira, Da Figueiredo Vilela, Santos, Lima, & Schwan, 2018).

Cocoa specific aroma can be defined as the aromatic properties that form during the cocoa processing and by the help of enzymatic reactions that mostly occur during the fermentation process of the cocoa beans. This fermentation process is complex transformation of the chemical reactions which contains: formation of organic acids, degradation of proteins, formation of insoluble compounds and hydrolization of glycosides. Fermentation is followed by drying, steam pre-treatment (debacterization step) and roasting processes where Maillard reaction takes place between amino acids/peptides and reducing sugars formed during fermentation and also some organic acids are removed from the cocoa. Effective debacterization can be performed by adding water and assuring the presence of steam in the equipment. Roasting temperatures, holding times and amount of water added vary according to the applied equipment and the desired flavor profile of the product. Usually, the final roasting temperature is between 110 °C and 140 °C. Microbiological tests must be carried out for each specific roasting profile to ensure that it kills all pathogens for example Salmonella and reduces the total bacterial content (Beckett, 2009). Many odor substances involving pyrazines, furans, aldehydes, ketones, pyrroles and aldols are formed during Maillard reactions (taking place during drying, roasting and conching) which are important for the aroma characteristics of cocoa and chocolate (Crafack et al., 2014).

Type and amount of ingredients (cocoa, sugar, fat, milk powder, emulsifiers) and production process of the chocolate, especially conching are also crucial factors for chocolate aroma. Aroma is influenced by the volatile components and behavior of the continuous fat phase, affecting the liberation of volatiles into the mouth headspace and taste perception (Khairy, Saadon, Zzaman, Yang, & Easa, 2018).

Evaluation of aroma components is one of the most interesting studies in the food research area since chocolate has been commercialized. This a big challenge because significant attention has been given to chocolate and chocolate products. The use of analytical tools and sensory analysis offers interesting opportunities for quality control of cocoa-based products, enabling a great understanding of the relationship between aroma compounds and sensory attributes. Instrumental methods are needed to better characterize the levels of these important aroma compounds and understand the evolution of this parameter after harvest, according to the cultivar and the pre-and post-harvest factors. Sensory evaluation has been stated to be a good way to assess consumer preferences. Therefore, a sensory guided approach is needed to differentiate those volatiles being crucial for cocoa flavor from those having low or no impact.

In this study, factors affecting aroma composition of the chocolate and methods performed for determination of volatile compounds profile is provided.