Pennsylvania State University researchers have pinpointed a gene involved in setting the melting point of chocolate, RedOrbit says.
Mark Guiltinan and his colleagues report in Frontiers in Plant Science that they characterized the eight putative soluble stearoyl-acyl carrier protein (ACP) desaturase (SAD) isoforms within the cacao genome. SAD, they note, catalyzes the conversion of stearoyl-ACP to oleoyol-ACP and affects the ratio of saturated to unsaturated fatty acids.
TcSAD1, they report, is expressed in all plant tissues, while TcSAD3and TcSAD4 are expressed mainly in flowers. In an Arabidopsis model, the researchers found that TcSAD1 could rescue all AtSSI2-related phenotypes, indicating TcSAD1 is a key gene in cocoa butter biosynthesis.
"The other SAD genes appear to play other roles in the growth of the chocolate tree, such as flower and leaf development, where these fatty acids play important roles as key components of various membrane systems," Guiltinan says in a statement. "This information can be used to develop biomarkers for screening and breeding of new cacao varieties with novel fatty acid compositions of cocoa butter."