Sensory Analysis and Product Development

Sensory panel
Sensory test prepared for tasting

The focus of the Sensory laboratory is to determine the consumer acceptability of existing, as well as newly developed food products.  For this type of test, 75 to more than 300 panellists can be recruited to perform a simple hedonic testing by indicating their ‘liking of’ a product.  Different attributes can also be included in this test, e.g., in die lowering of the salt content of a dairy product, such as Feta cheese, it is necessary to determine the ‘liking of’ the salt taste of all the samples.

Consumer panels can also be used to describe the sensory attributes of food product, by using the so-called CATA (Check-All-That-Apply) questions: a list of applicable sensory descriptors is presented to the panelists and they are asked to tick the descriptors that they think describe the sample best. Thirteen amaranth genotypes and 12 edamame genotypes have been profiled in this way, to advise the South African farming industry on which genotypes are more suitable to the South African taste.

Principal Investigator

Dr Carina Bothma

Dr Carina Bothma
+27 51 401 2216

The traditional way of describing a product is done by using a trained panel of 10-12 individuals, who are extensively trained for hours. This type of test is still done, as these trained panelists can also quantify every attribute.  Different cooking methods have been tested on agave flowers, an under utilised vegetable in Lesotho, by using generic descriptive analysis.

It is necessary, when developing new food products, to ask consumers to indicate which attributes need adjustment.  The Just-About-Right (JAR) test is done in these cases. Again, different attributes are chosen for the JAR test and consumers are asked to indicate whether an attribute is just about right, or whether the intensity is too high or too low. In this way, researchers know exactly which attributes need further attention. New products have been developed to introduce amaranth and edamame to the consumer. 

Sensory testing sample setup
Three-digit coded samples are placed on trays,
according to different permutations, for every panelist

Tasting cubicles
The sensory lab has 12 tasting cubicles,
each one equipped with a light signalling system

Sensory cubicles equipped with computers using CompuSense software
The sensory cubicles are equipped with computers,
using the CompuSense software

Product development is done as undergraduate, honours and postgraduate courses.  Various topics have been attempted in the past, including developing new products from food waste, lowering salt content of various dairy (Feta cheese and cottage cheese) and meat products and incorporating under utilised vegetables, such as amaranth, introducing ‘new’ crops to South Africa, such as edamame (vegetable soy) and fonio (pseudo grain).

Entomophagy, the consumption of insects by humans, is currently also being investigated among South African consumers and new food products are being developed from cricket flour.

Consumer behaviour is extremely important and along with social media, influence buying power of the South African population.  Also incorporated into the sensory laboratory, is the use of eye movement tracking.  A study on the effect of foodporn on eye movement and whether it will influence the consumer to prepare a recipe on social media, is currently being investigated.

Amagwenya / vetkoek is a very important food product in South Africa and two Masters students are investigating the consumer’s behaviour towards its consumption, as well as the overall liking thereof.  The sensory attributes of amagwenya / vetkoek, purchased from street vendors and commercial outlets, are also being profiled, using CATA.  This technique also enables the consumer to describe their ‘ideal product’ and to compare it against the available samples.  Also important is the determination of the quality of oil being used by the street vendors and commercial outlets, and these analysis will be conducted with the assistance of Prof Arno Hugo’s laboratory.

Fonio, a ‘new’ pseudo grain to South Africa, has also been profiled, along with two other pseudo grains, teff and quinoa, and three grains, namely maize, sorghum and millet, by preparing porridge samples.  An exciting new product was also developed, turning uburo (black fonio) into a meatball-type product, served with a variety of sauces.

Research Highlights/News

Dr Bothma and one of the master's students, Carla Hills, attended the Pangborn Conference in Edinburgh, Scotland, from the 28 July to 1 August 2019, and presented two posters.

Recently Featured Publications

  • Hiscock L, Bothma C, Hugo A, van Biljon A, Jansen van Rensburg WS (2019) Hedonic evaluation and check-all-that-apply (CATA) question for sensory characteristic of stewed vegetable Amaranthus. Journal of Food Science and Technology,
  • Hiscock L, Bothma C, Hugo A, van Biljon A, Jansen van Rensburg WS (2018) Overall liking and sensory profiling of boiled Amaranthus leaves using the Check-all-that apply question. CyTA Journal of Food 16:1, 822-830.
  • Cluff M, Kobane IA, Bothma C, Hugo CJ, Hugo A (2017) Intermediate added salt levels as sodium reduction strategy: Effects on chemical, microbial, textural and sensory quality of polony. Meat Science, 133, 143-150.
  • Mielmann, A, Bothma, C, Hugo, C, Hugo, A (2017). A comparative study of the chemical composition of Lucerne (Medicago sativa L.) and spinach beet (Beta vulgaris var. cicla L.). South African Journal of Botany, 108, 8-14.
  • Faihst T-J, Myburgh J, Bothma C, Hugo C,  Hugo A (2017) The microbial, physical, chemical and sensory effects of synthetic conjugated linoleic acid supplementation in yogurt.  Journal of Functional Foods, 70 (2), 228-236.


Elfrieda Lötter: Marketing Manager
T: +27 51 401 2531

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