From Geoseph

This is a summary comparing the composition of cocoa butter from cacao grown in different regions of Peru. Cocoa butter is the fat contained in cocoa butter, a triglyceride made of mainly 3 fatty acids, but a small percentage of the fat content in cocoa is also made up of other fatty acids in various levels. This variation likely contributes to known differences in cocoa butter hardness, melting points, and even viscosity of chocolate made with different beans. We often say that cocoa beans contain 50% cocoa butter, but it can actually range quite a bit depending on the genetics and growing conditions. This research summary gives you some solid insight into how much cocoa butter can vary between varieties and growing regions even within one region of Peru. Consider this information when you’re analyzing the variations in the chocolate you make or even the chocolate you taste.

Introduction

Cocoa, the tree, belongs to the taxonomic family Malvaceae (flowering plants including cotton, durian, okra, and hibiscus), and the genus Theobroma (which also includes other pod growing trees like bicolor and Cupuaçu). It is native to South America and considered a very important global commodity due to it’s role in chocolate manufacturing. Peruvian cocoa and its byproducts are also highly valued worldwide for the fine-aroma cocoa beans.

Some consider cocoa beans to be a superfood due to its antioxidant capacity and polyphenol content linked to health benefits. It’s suggested as well that chocolate or cocoa may favorably alter the intestinal microbiota (8).

Cocoa is also high in fat, a fat we refer to as cocoa butter. Fats and oils can be composed of 4 types of fatty acids: polyunsaturated, monounsaturated, saturated, and trans fatty acids. Cocoa butter is a triglyceride (a fat molecule made up of 3 fatty acids) and contains two saturated fatty acids (stearic and palmitic), and one monounsaturated fatty acid (oleic). There are many factors which influence the physiochemical characteristics of total fats and the fatty acid profile of cocoa. This can include the geographic region they grow, climatic conditions, growing and cultivating techniques, genetics/cultivar type, and harvest index (12, 13). A study by Salinas & Bolivar (14) found Venezuelan chocolates have high variability in their fatty acid makeup.

There have been few studies carried out on the makeup of fatty acids in Peru-origin cocoa beans. The objective of this research was to evaluate total fat content and fatty acid profile of 30 ecotypes (samples) of fine-aroma cocoa from Amazonas, Cajamarca and San Martin regions.

Materials and methods

Thirty samples of 500 g each were collected between April and September 2018 from Amazonas (26 samples), Cajamarca (2 samples), and San Martin (2 samples). Each sample was assigned a codes (see Table 1), they are:

ACJ-1 to ACJ-19, Amazonas from Carjaruro
ABG-1 to ABG-4, Amazonas from Bagua Grande
ACP-1 to ACP-3, Amazonas from Copallin
CYY-1 and CYY-2, Cajamarca from Yanayacu
SJJ-1, San Martin from Juanjui
SPR-1, San Martin from Pinto Recodo

The fat was then extracted from the cocoa samples, and then the fatty acids were identified and quantified by GC-FID (gas chromatography and flame ionization detector). The results of the total fat content (Table 1) are shown as mean values with standard deviations. Then, the 30 ecotypes (the 30 samples) were classified into five hierarchical groups (presented as clusters) according to their fatty acid profiles (Figure 2). Tests were done to determine the differences between these clusters/groups. Then, Pearson’s correlation was applied to measure if there was a relationship between the altitude of where a sample was grown and it’s fatty acid profile.

Results

Total Fat

All 30 samples (ecotypes) were different in their total fat content. In Table 1, the 30 samples were placed into 4 groups according to their total fat percentage and labeled a-d (placed next to their percentage and standard deviation values). Group a contained two samples, both at around 30% fat, while d contained 14 samples at with fat percentage around 20% or lower. According to the Pearson’s correlation test, there was no significant correlation between fat percentage and growing altitude.

Identification and quantification of fatty acids for the classification of fine-aroma cocoa ecotypes

In this study, 10 fatty acids were identified in the cacao from Northeastern Peru (see Table 2). Six of these were saturated fatty acids (Myristic, Palmitic, Margaric, Stearic, Arachidic, and Behenic), two were monounsaturated (Palmitoleic and Oleic), and two were polyunsaturated (Linoleic and Linolenic).

Table two displays the 10 cacao samples on the left side of the table, and the 10 fatty acids at the top of the table. The predominate fatty acids found in all samples are Palmitic, Stearic, and Oleic, and represent over 80% of the fat composition of cocoa beans. On the other extreme, Behenic was only found in 7 samples and was found at very low amounts, and so this fatty acid has a lower bioavailability in cocoa beans.

Discussion

The average total fat of the 30 samples ranged from 17.51 to 30.87%. The four groups (a-d) show that total fat content in fine-aroma cocoa can vary quite a bit. This variation may depend on the region of where the cacao was grown. However, the variation can also depend on the type of cocoa, the degree of maturity, quality of fermentation and drying (12, 18), genetics, and environmental factors. The fat percentage in this study was quite low compared to Riano H. et al. (13) where 53.76% total fat was reported for cocoa from Peru. However, fine cacao can have fat percentages lower than 50% (19), but also have higher values of phosphorus, iron, zinc, sodium, and selenium (20). Note that the researchers here mention that the low levels of total fat in this study may have been influenced by the size of the nibs used for fat extraction (21), and by the manual sample preparation.

The 10 fatty acids and relative concentrations that were identified here are the same as those reported by Melo et al. (22), with similar results by Torres-Moreno et al. (20) as well. Palmitic (> 25%), Stearic (> 33%), and Oleic (> 34%) are the most important fatty acids identified in the cocoa beans, as well as in chocolate (24). Determining the fatty acid profiles of cocoa beans may help those who wish to take into account desired manufacturing and nutritional characteristics (25). It’s interesting to note Palmitic fatty acid levels correlate negatively with stearic, oleic, and linoleic acids (26). The higher the palmitic concentration, the lower the other three. The climate the cacao grows in may be a factor, suggesting that higher growing temperatures the higher the concentration of palmitic acid.

Many authors suggest the differences in fatty acid profiles of cocoa are explained by geographical origin (20). In the dendrogram (Figure 2), cluster 3 contained the samples with the lowest percentage of saturated fatty acids (70.70%) and therefore the highest percentage of saturated fatty acids (29.29%). On the other hand, cluster 2 contained the samples with the highest percentage of saturated fatty acids (71.71%) and the lowest percentage of unsaturated fatty acids (28.39%).

Although it is stated that high levels of dietary saturated fatty acids are harmful to human health if consumed in high amounts, they don’t all metabolise the same way. Stearic acid (saturated) which is one of the main 3 fatty acids identified in cocoa is unique in that human studies have shown that it is a very poor substrate for the synthesis of triacylglycerols when compared with other saturated fatty acids. Therefore, Stearic is stated to have a protective factor against obesity (27).

Polyunsaturated fatty acids (such as linolenic and linoleic) identified here do not appear to vary much between the 5 clusters. These fatty acids produce energy and reconstitute the fatty tissue, and according to McClements & Ozturk (29) along with omega-3, carotenoids, and phytosterols, play an important role in improving human health and well being. Therefore identifying the levels of these fatty acids in fine-flavoured Peruvian cocoa is beneficial. Cabezas-Zabala et al. (30) mention that increased consumption of monosaturated and polyunsaturated fatty acids can reduce LDL cholesterol. This feeds into the growing interest of functional food development to produce health benefits such as anti-inflammatory, antioxidant, anticancer, and cholesterol-lowering properties. The proteins and peptides in Cocoa may also be developed as an ingredient in functional foods to mitigate obesity and associated disorders (31).

Total Fat Content and Fatty Acid Profile of Fine-Aroma Cocoa From Northeastern Peru