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UFS boasts with newly renovated sensory laboratory

21 January 2020 | Story Leonie Bolleurs | Photo Leonie Bolleurs

Prof Danie Vermeulen, Prof Arno Hugo, and master’s student in Consumer Sciences, Mandisa Masuku in the newly renovated sensory laboratory in the Agricultural Building on the UFS Bloemfontein Campus.

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.

News Archive

Researcher part of project aimed at producing third-generation biofuels from microalgae in Germany

2016-05-09

Some of the researchers and technicians among the tubes of the Novagreen bioreactor (Prof Grobbelaar on left)

A researcher from the University of the Free State (UFS), Prof Johan Grobbelaar, was invited to join a group of scientists recently at the Institute for Bio- and Geo-Sciences of the Research Centre Jülich, in Germany, where microalgae are used for lipid (oil) production, and then converted to kerosene for the aviation industry.

The project is probably the first of its kind to address bio-fuel production from microalgae on such a large scale.

“The potential of algae as a fuel source is undisputed, because it was these photoautotrophic micro-organisms that were fixing sunlight energy into lipids for millions of years, generating the petroleum reserves that modern human civilisation uses today. However, these reserves are finite, so the challenge is marrying biology with technology to produce economically-competitive fuels without harming the environment and compromising our food security. The fundamental ability that microalgae have to produce energy-rich biomass from CO2, nutrients, and sunlight through photosynthesis for biofuels, is commonly referred to as the Third-Generation Biofuels (3G),” said Prof Grobbelaar.

The key compounds used for bio-diesel and kerosene production are the lipids and, more particularly, the triacylglyserols commonly referred to as TAGs. These lipids, once extracted, need to be trans-esterified for biodiesel, while a further “cracking” step is required to produce kerosene. Microalgae can store energy as lipids and/or carbohydrates. However, for biofuels, microalgae with high TAG contents are required. A number of such algae have been isolated, and lipid contents of up to 60% have been achieved.

According to Prof Grobbelaar, the challenge is large-scale, high-volume production, since it is easy to manipulate growth conditions in the laboratory for experimental purposes.

The AUFWIND project (AUFWIND, a German term for up-current, or new impetus) in Germany consists of three different commercially-available photobioreactor types, which are being compared for lipid production.

Manipulated Chlorella with high lipid contents (yellow) in the Novagreen bioreactor

The photobioreactors each occupies 500 m2 of land surface area, are situated next to one another, and can be monitored continuously. The three systems are from Novagreen, IGV, and Phytolutions. The Novagreen photobioreactor is housed in a glass house, and consist of interconnected vertical plastic tubes roughly 150 mm in diameter. The Phytolutions system is outdoors, and consists of curtains of vertical plastic tubes with a diameter of about 90 mm. The most ambitious photobioreactor is from IGV, and consists of horizontally-layered nets housed in a plastic growth hall, where the algae are sprayed over the nets, and allowed to grow while dripping from one net to the next.

Prof Grobbelaar’s main task was to manipulate growth conditions in such a way that the microalgae converted their stored energy into lipids, and to establish protocols to run the various photobioreactors. This was accomplished in just over two months of intensive experimentation, and included modifications to the designs of the photobioreactors, the microalgal strain selection, and the replacement of the nutrient broth with a so-called balanced one.

Prof Grobbelaar has no illusions regarding the economic feasibility of the project. However, with continued research, optimisation, and utilisation of waste resources, it is highly likely that the first long-haul flights using microalgal-derived kerosene will be possible in the not-too-distant future.

Prof Grobbelaar from the Department of Plant Sciences, although partly retired, still serves on the editorial boards of several journals. He is also involved with the examining of PhDs, many of them from abroad. In addition, he assisted the Technology Innovation Agency of South Africa in the formulation of an algae-biotechnology and training centre. “The chances are good that such a centre will be established in Upington, in the Northern Cape,” Prof Grobbelaar said.

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