Throughout history man has been looking for new ways to make their food more appetizing. They first used herbs and spices and later, the use of chemically synthesized compounds was favoured. With the increased production of processed foods, additives such as flavours became crucial to food industries. Consumers have become increasingly aware of leading a more health and nutrition-conscious lifestyle. Thus there has been a great demand for products to be labelled as natural. Most natural aromas have been derived from plants and to a lesser extent from microorganisms. There are several drawbacks involved in the extraction of volatiles from plants and thus the use of microorganisms for the production of natural aromas is an attractive alternative. FABI and the CSIR contain collections of fungi that are associated with various environmental niches from South Africa.  The CSIR hosts fungi that are associated with food and agricultural environments. FABI hosts a culture collection where many of their fungi are obtained from South African forests and plantations. Many fungi found in these environments are known to produce aromatic substances, including pheromones.

 

One of the groups of aromas that is of interest to me is the pyrazines. These are aromatic heterocyclic nitrogen containing compounds, where the alkylated and methoxylated forms exhibit strong odorous properties. They have many uses as flavour compounds in the food industry and are also used in the synthesis of various pesticides, insecticides, drugs and dyes.

 

I am currently doing my MSc degree at the Center for Applied Mycological Studies, CAMS, situated in FABI, under the supervision of Dr GJ Marais, Prof. ER Rhower, and Dr PJ Van Zyl. The project is funded through the Centre for Tree Health Biotechnology (CTHB).  The title of my project is: The Production of Flavours and Fragrances from South African Fungi. It involved the screening of fungi from the FABI and CSIR culture collections through a sensory evaluation for the nutty, beefy, caramel, chocolate, green and potato aromas known to be characteristic of pyrazines. Thereafter pyrazine production in the 11 most prominent fungi was confirmed through GC-MS-TOF. Two fungi producing methoxypyrazines are used to further investigate their ability in a solid-state fermentation process using soy press cake. My project has been extremely exciting thus far and I intend to enjoy it to the end!