Identification of Climate and Genetic Factors That Control Fat Content and Fatty Acid Composition of Theobroma cacao L. Beans

Abstract

The main ingredients of chocolate are usually cocoa powder, cocoa butter, and sugar. Both the powder and the butter are extracted from the beans of the cacao tree (Theobroma cacao L.). The cocoa butter represents the fat in the beans and possesses a unique fatty acid profile that results in chocolate’s characteristic texture and mouthfeel. Here, we used a linkage mapping population and phenotypic data of 3,292 samples from 420 progeny which led to the identification of 27 quantitative trait loci (QTLs) for fatty acid composition and six QTLs for fat content. Progeny showed extensive variation in fat levels and composition, with the level of palmitic acid negatively correlated to the sum of stearic acid, oleic acid, and linoleic acid. A major QTL explaining 24% of the relative level of palmitic acid was mapped to the distal end of chromosome 4, and those higher levels of palmitic acid were associated with the presence of a haplotype from the “TSH 1188” parent in the progeny. Within this region of chromosome 4 is the Thecc1EG017405 gene, an orthologue and isoform of the stearoyl-acyl carrier protein (ACP) desaturase (SAD) gene in plants, which is involved in fatty acid biosynthesis. Besides allelic differences, we also show that climate factors can change the fatty acid composition in the beans, including a significant positive correlation between higher temperatures and the higher level of palmitic acid. Moreover, we found a significant pollen donor effect from the variety “SIAL 70” which was associated with decreased palmitic acid levels.

QTL mapping and identification of SNP-haplotypes affecting yield components of Theobroma cacao L.

“…In other studies, the region from 1414 bp to 1,686,245 bp on chromosome IV is associated with other traits that may directly affect the cacao production, such as cherelle wilt ratio, fresh bean weight, fresh weight/pod, total number of pods, and disease resistance 24 , fatty acid composition 25 and sexualcompatibility 26 . Another QTL associated with fat content in the MP01 population was also found on chromosome IV from 19,637,361 bp to 26,233,319 bp 25 . The top position of this QTL is located at the distance of 4,132,875 bp of one SNP mapped in our study for DBW, Tcm003s30366194.…”

“…The top position of this QTL is located at the distance of 4,132,875 bp of one SNP mapped in our study for DBW, Tcm003s30366194. In this study, fat content represents 50.2-62.4% of the total dry weight of a bean 25 , therefore, it is also an important yield component. In our study, the most significant region was located from 0.11 to 5.16 cM of chromosome IV.…”

“…4-7). So far in the MP01 population, the maternal alleles have been reported as the ones more affecting the economically important traits, such as disease resistance 11,29 , and fat content and fatty acid composition 25 . Likewise, our study showed that the alleles from 'TSH 1188' are the ones controlling the QTL regions with a higher LOD scores, such as the one found on chromosome IV.…”

“…The female parent is related to Iquitos and Nanay genetic groups 13,24 , and the male parent has predominant ancestries from Iquitos, Criollo, and Amelonado 13,14,24 . Those parents contrast for many important traits, and the MP01 progenies segregate for disease resistance 11,29,51 , pod color 5 , fat content and fat composition 25 . The MP01 population also segregates for yield.…”

Lyophilized Drug-Loaded Solid Lipid Nanoparticles Formulated with Beeswax and Theobroma Oil

“…Theobroma oil is an edible fat extracted from the seeds of Theobroma cacao . It typically contains palmitic, stearic, oleic, and linoleic acids [ 11 ]. Theobroma oil melts at body temperature (37 °C) and is extensively used in cosmetics, food, and pharmaceuticals, especially suppositories.…”