Imagine all food tasting the same …

Fortunately, this is not the case, as consumers like to enjoy what they eat. Tasting food is important because it enables suppliers to adapt food products to consumers’ preferences.

According to Prof Arno Hugo of the Department of Microbial, Biochemical and Food Biotechnology at the University of the Free State (UFS), it is important for food companies to make sure that new food products are acceptable to consumers before launching such products. Often, companies also want to confidentially compare and profile their new or even established products against their competitors’ products. Lately, food companies also have the need to adapt European or North American food products for the local consumer (Africanisation of food products). Independent sensory laboratories are needed for such work. 

Dr Carina Bothma, Senior Lecturer and sensory science expert – also from the Department of Microbial, Biochemical and Food Biotechnology – who manages the sensory laboratory, says the laboratory at the university performs sensory analysis, which is a scientific discipline used to evoke reactions from humans regarding the five senses of sight, smell, touch, taste, and hearing. These reactions can be captured from first bite to complete mastication and are then statistically analysed and interpreted by a sensory analyst.

With the support of the Dean of the Faculty of Natural and Agricultural Sciences, Prof Danie Vermeulen, a project to the value of R3 million to upgrade the existing sensory laboratory in the Agricultural Building on the UFS Bloemfontein Campus, is nearing completion. Minor improvements will be completed by June 2020.

According to Dr Bothma, upgrades were done in three sections, including a training area (with seating for 12 trained panellists); a computerised 12-booth tasting area (with a three-light communication system); and a preparation area. The latter consists of a walk-in fridge and walk-in freezer, a 10-rack industrial steam-jet oven, a ventilation system to control and maintain a negative pressure in the preparation area – so that odours do not move to the tasting area, two mobile units with four gas plates in each unit, and a sputum and control area equipped with a computer.

Prof Hugo, who is mainly responsible for planning trials and statistical analyses of sensory data, says the sensory laboratory is truly a fantastic facility and big asset for the university. “I think it is one of the best-planned and best-equipped sensory laboratories in South Africa.”

Alternative food products profiled

He continues: “Several sensory studies have been done regarding the influence of salt reduction on the meat quality of various meat products, as well as the effect of different feed supplements on meat quality. Meat was also evaluated, comparing the meat quality of animals from different production systems.”

Dr Bothma states that food products to be evaluated vary and may include new products in product development. “Several interesting food products have been tested in the lab so far. Underutilised vegetables such as amaranth and cactus pears, and newly introduced crops such as edamame, have been evaluated.  Ancient grains such as fonio have also been profiled.  An African staple, amagwinya, is currently being profiled, as well as food products containing insect flour,” she says.

Testing and teaching

According to Dr Bothma, a trained panel consisting of 10 to 12 panellists is highly trained to verbally describe a food product or characteristic.  For other tests, consumers of a specific food product to be tested, are sourced. Such a panel can consist of between 75 and 300 persons, depending on the requirements of the client.  Panels can also be compiled according to specific demographics. All demographic information remains anonymous.  

Sensory analysis forms part of academic research projects and a number of PhD and master’s degrees have been done in the laboratory. 

She says: “Postgraduate students work in the sensory lab under supervision of the sensory analyst. They personally recruit panellists on the campus, referred to as 'convenience sampling'. These assistants do the preparation for the tasting, preparing up to 500 individual samples for a test that has 100 panellists and five products.  They attend to the panellists, serve the samples, collect and decode ballot sheets, and enter data into Excel for statistical analysis.”

More than 20 accredited scientific articles have already been published from research done in this laboratory.