INTRODUCTION

Chocolate is a key ingredient in many types of food and is listed as one of the most preferred flavors by people around the world. The particular flavor of chocolate is due to the mixture of hundreds of compounds that originate from precursors in cocoa beans during postharvest treatments (^{Di Carro et al., 2015}). The global market for cocoa beans has two main categories: "fine" and "bulk" or "ordinary". According to ^{Afoakwa et al. (2008)}, Latin America and the Caribbean provide 80% of fine cacao, which is widely recognized by processors and covers a small amount of production, equivalent to 5-8% of global supply of cacao, which, according to the FAO, reached 5,756,953 t in 2020, with Colombia contributing 63,416 t (^{FAO, 2022}). The International Cacao and Chocolate Organization (ICCO) classified Colombian cacao as fine aroma, which offers more economic and social benefits to cacao producers than to regular cacao producers (^{Ríos et al., 2017}).

Quality classification is primarily based on the aromatic composition of cacao, where genotype is the most important factor; however, the agroclimatic conditions of a crop and harvesting, fermentation, drying and processing processes are factors that have significant effects on the formation of volatile and non-volatile components and define the final quality of the product (^{Sim et al., 2016}; ^{Palacios et al., 2021}). Different studies carried out in countries such as Ghana, Trinidad and Tobago, Mexico, Venezuela, Peru and Ecuador have shown that the sensory profile of cacao varies with genotype and conditions in the origin region (^{Frauendorfer and Schieberle, 2008}; ^{Pino et al., 2011}; ^{González et al., 2012}; ^{Ordoñez et al., 2020}).

More than 500 volatile compounds have been detected in cacao, whose mixture includes alcohols, aldehydes, ketones, acids, esters and pyrazines, among others, which are developed during fermentation, drying and roasting, generate the characteristic attributes of chocolate, and have differences in the volatile compounds in cacao with different geographical origins (^{Argout et al., 2008}; ^{Cambrai et al., 2010}; ^{Batista et al., 2016}).

According to ^{Argout et al. (2008)}, flavor is one of the more important quality criteria for chocolate manufacturers, which is why important advances have been made in its assessment in recent years; however, because of the difficulty in taking these measurements, technical techniques have been used, including sensory and chemical evaluations with chromatography. Sensory evaluation is an important technique for determining quality based on sensory properties, which has been used by trained panels of evaluators who use precise measurement techniques for human responses to food. This technique has been widely used for food, including product development, classification studies, and quality determination for products with high commercial value (^{Vázquez-Ovandoet al., 2012}; ^{Cevallos-Cevallos et al., 2018}).

Global standards and protocols have been developed for the evaluation of cacao and chocolate flavor quality by the Cacao of Excellence Program (^{CoEx, 2015}), which recognizes the quality and diversity of cacao in producing countries (International Standards for the Assessment of Cocoa Quality and Flavour - ISCQF, 2022). These standards established the flavor profile by identifying and measuring the intensity of basic and complementary attributes that determine the attractiveness of the final product and therefore the desirability of cacao and chocolate products (^{Streule et al., 2022}). In recent years, consumer interest in high-quality foods with a clear geographic identity has grown rapidly (^{Luykx and Van Ruth, 2008}; ^{Cevallos-Cevallos et al., 2018}).

Given the advances in determining cacao quality in the global environment, the fact that Colombia has been recognized as a country that produces fine aroma cacao (^{ICCO, 2022}), and this crop’s increased relevance in agricultural development, comparative evaluations of the expression of quality characteristics are needed, taking into account clone diversity from different cacao producing regions. This study aimed to elucidate the sensory profiles of cacao cultivated in Colombia.

MATERIALS AND METHODS

RESULTS AND DISCUSSION

The correlation matrix (Tab. 2) shows the relationship between each pair of sensory attributes: cocoa, acid, astringent, bitter, fruity, floral, nutty, sweet and green/raw, with high positive correlations between astringent and bitter (r=0.85), astringent and green/raw (r=0.78), and bitter and green/raw (r=0.77), demonstrating a direct relationship between the astringent, bitter, and green/raw notes in the cacao liquor. Another high and positive correlation was established between fruity and sweet, which are perceived in well-fermented fine cacao (^{Counet et al., 2004}). Another high and positive correlation was found between cacao and fruity (^{CoEx, 2015}).

Several authors have reported that the presence of these attributes is associated with high polyphenol contents that are important components of cocoa flavor, responsible for bitterness and astringency that differs between genotypes, environmental and that are present in low-fermented cacao beans, which significantly affects the sensory qualities of chocolate (^{Afoakwa et al., 2012}; ^{Owusu et al., 2012}; ^{Ramos et al., 2014}; ^{Menezes et al., 2016}; ^{Sim et al., 2016}; ^{Ordoñez et al., 2020}). According to ^{Menezes et al. (2016)}, there is a positive correlation between the level of fermentation and the expression of floral, fruity and sweet aromas. High and negative correlations were found between bitter and fruity, bitter and nutty, fruity and green/raw, and nutty and astringent, demonstrating an inverse relationship between these attributes. These inverse relationships indicate that, when fermentation is adequate, aromas such as nutty, fruity, and floral can be expressed and are not masked by attributes related to bottom fermentation, allowing chocolate to develop all its characteristic aromas (^{Rodríguez-Campos et al., 2011}; ^{Ramos et al., 2013}).

According to the Principal Component Analysis (PCA), two components were obtained that had a vector or eigenvalue greater than 1. CP1 had an eigenvalue of 4.34, and CP2 had 1.83, which explained the behavior of the genotypes in the three locations, accumulating 68.52% of the total variance and indicating that they are the more important in terms of absolute variance. In the first component, the greatest contribution was from the green/crude, bitter, astringent, fruity, nutty, and cocoa attributes, and the second component was from the acid, floral, and sweet attributes (Fig. 1).

Figure 1 shows that the first component accumulated 48.18% and was represented on the positive axis by the astringent, green/crude, bitter and acid attributes. On the negative axis of component 1, this component was represented by the floral, sweet, fruity, cocoa and nut attributes that are perceived in cacao when fermentation has allowed the components that define cacao quality to form. These results demonstrate the inverse relationship between the bitter, astringent, acid and green/crude attributes with cocoa, fruity, floral, nutty and sweet notes, which have also been seen in other studies. These results led to the suggestion that the expression of attributes that describe the pleasant sensory impression of cacao can be masked by the presence of unpleasant attributes that affect the final quality of chocolate (^{Rodríguez-Campos et al., 2011}; ^{Batista et al., 2016}).

Figure 1. Representation of the first two principal components for the sensory attributes of 16 cacao genotypes in three regions of Colombia. The final letters of the genotype names correspond to the departments: S = Santander, A = Arauca and H = Huila. 

Similarly, figure 1 shows that the genotypes formed three groups that coincided with the regions where they were evaluated, where most of the genotypes with the final letter S that were evaluated in Santander were in the negative quadrant of the first component and the positive quadrant of the second one. The genotypes evaluated in Arauca with the final letter A were in the negative axis of the second component, and those from Huila (H) were in the positive quadrants of the first and second components. The genotypes in the Santander group presented attributes such as fruity, cocoa, sweet and floral. The Arauca group had nutty notes, and the Huila group had astringent, green and bitter notes.

The samples from Huila presented profiles where the attributes were related to low fermentation as a result of various causes that may be related to the temperature reached in the aerobic phase, the populations of microorganisms, the water content, and the amount of mucilage around the grains (^{Streule et al., 2022}). According to ^{Sukha et al. (2008)}, these variations raise questions related to the importance of the genotype-environment relationship and how their interaction during fermentation and drying affect cacao flavor attributes.

The groupings by regions were consistent with those reported by other authors who evaluated the expression of chemical and sensory compounds of cacao in different regions, demonstrating that there are differences in sensory profiles influenced by environmental and management conditions (^{Ramos et al., 2013}; ^{Menezes et al., 2016}). ^{Carrillo et al. (2014)} observed considerable variations that resulted from altitude in the concentrations of cacao volatile compounds from different geographic regions of Colombia. These compounds are correlated with the aromatic profile of cacao after being fermented and dried, as has been described by several authors (^{Frauendorfer and Schieberle, 2008}; ^{Rodríguez-Campos et al., 2011}; ^{Menezes et al., 2016}; ^{Sim et al., 2016}).

The differences in the regions may also have been generated by microorganisms present during cacao fermentation that are responsible for the production of metabolites and flavor precursors that affect quality (^{Batista et al., 2016}; ^{Streule et al., 2022}). According to ^{Moreira et al. (2013)} and ^{Ramos et al. (2014)}, the bacterial communities present in the fermentation process vary according to the conditions of the pulp, such as sugar and moisture content, that can change with the genotype and the environmental conditions where the fermentation and drying process takes place.

Additionally, there is high genetic variability in Colombian cacao, represented in the genotypes evaluated in this study, which may play an important role in the variability of sensory profiles and grouping by region. According to ^{Ramos et al. (2013)}, different varieties can offer characteristics that favor the growth of diverse communities of microorganisms during the fermentation process, which must be taken into account in management for the production of high-quality cacao.

According to the results obtained in several recent studies, since cacao varieties influence the quality of chocolate, different varieties should be fermented separately using yeast starter cultures to improve standardization of the cacao fermentation process (^{Ramos et al., 2014}; ^{Batista et al., 2016}; ^{Menezes et al., 2016}; ^{Bastos et al., 2019}).

The results found in the present work demonstrated what has been established by several authors, where genotype and environmental and management conditions where the crop is developed influence the sensory profile and the quality of the chocolate (^{Luna et al., 2002}; ^{Cambrai et al., 2010}; ^{Porras et al., 2019}). These results will aid future classifications according to the geographical area of cacao-producing regions or "terroir", such as that established for wine, coffee, and other foods, in addition to providing a scientific basis for quality certification programs, as suggested by ^{Bertoldi et al. (2016)}.

Table 3 show the results of the sensory evaluation panel for each genotype in the three locations. In the three localities, typical fruity notes of Trinitario-type cacao stood out. According to ^{Johnson et al. (2009)}, the ICS and TSH 565 materials have intense fruity, floral, nutty and chocolate notes with pleasant secondary aromas such as molasses, caramel and raisins. According to the organoleptic evaluation carried out by ^{Boza et al. (2014)} and ^{Menezes et al. (2016)}, CCN 51 exhibits a moderate amount of cacao flavor and high levels of bitterness and astringent, consistent with the profile found in the three locations. This clone is not appreciated in the fine cacao market.

The EET 8, ICS 1, ICS 39 and ICS 60 genotypes presented low intensity in the evaluated attributes, when compared with those of the other cultivars, possibly because the fermentation process was affected by the large size of the grains. On the other hand, most of the clonal selections presented attributes with greater intensity in the fruity, cocoa and nutty notes, especially FLE 3, FSV 41, FEC 2 and FEAR 5. This result is consistent with the report by ^{Sukha et al. (2008)}, who observed that the sensory profile varied between the cacao genotypes from Ghana and Trinidad. The latter had moderate cocoa flavor values and intense acid, floral, and fruity flavors. According to the results, the FEC 2 genotype had the highest intensity for the cocoa note and the lowest astringency. ICS 1 and FEC 2 presented floral notes, the FLE 3 and FSV 41 genotypes had nutty notes, and FTA 2 and FSA 13 presented fruity and sweet notes.

In general, each genotype had a different sensory profile, which, according to ^{Afoakwa et al. (2008)}, was mainly due to quantitative differences caused by aroma precursors, which are inversely proportional to the polyphenol content, as well as the sugar content and the enzymatic breakdown of polysaccharides, which are a significant source of precursors.

CONCLUSIONS

Some regional genotypes surpassed the CCN 51 genotype in the sensory profile, demonstrating the potential of regional clones for crop development and as a genetic resource in Colombia. Genetic and environmental conditions influenced the development of cacao flavor characteristics, and Colombian cacao has fine attributes. Sensory evaluations are a fundamental tool for evaluating the organoleptic quality of cacao and for geographical classifications as a basis for the development of denominations of origin for specialty markets.