Meet SA’s first PhD in biltong-making!
Stellenbosch University (SU) student, Maxine Jones, recently received her distinctly South African doctorate in food science from Stellenbosch University (14 March).
She has achieved a unique first: a PhD for research focusing exclusively on how to make good quality biltong. In the process the 27-year old says she has developed a scientifically proven recipe for making consistently delicious biltong.
Jones’ industry-based research project focused on different aspects of biltong processing, such as the use of standardised drying procedures to dry the meat at best.
The Capetonian, who matriculated from Wynberg Girls’ High, took note of factors such as temperature, humidity and air movement. She also investigated the presence of different yeasts, moulds and even bacteria that often occur on biltong, and that play a role in its shelf life.
“Quality and consistency is important to both the consumer and the biltong industry,” says Jones, who believes the local industry needs to standardise drying guidelines to ensure more consistent quality and to sidestep food safety issues.
“There are currently no processing guidelines for biltong production in South Africa, and this leads to vast differences in the end product.
“The biltong industry has become an economically important sector in the South African meat industry and has the potential for further growth, both nationally and internationally,” she said.
Jones also investigated export opportunities that are available to South African producers, and the certification processes and laboratory guidelines that they need to consider.
Her research path crossed with biltong during her MSc studies. Her research here involved testing the addition of rooibos tea extract to South African droëwors as a natural antioxidant in an effort to increase the shelf-life of the product.
Her field of research has subsequently landed her a job as the quality and food safety manager for Cape Deli Biltong in Cape Town.
Jones’ research has also taken her places, from Namibia and the Wageningen University in the Netherlands to an international conference in Thailand, and even Reunion Island, where she tested the spicing of biltong with ultrasonic equipment and its subsequent drying.
The equipment was available at the Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), with which SU’s Department of Animal Sciences enjoys ongoing cooperation.
“Biltong isn’t such a simple matter as we may think; there’s a science behind it,” says Jones. “With the increased popularity of biltong the research opportunities are vast, and this research is just the beginning of things to come.”
During the course of her project, Jones consistently dried biltong at temperatures around 25°C, at a relatively low humidity of 30%, and an air speed of about 0.2 meters per second.
Here are some of her findings:
- Adding vinegar in the salting/spicing step of beef biltong did not increase the time that the meat takes to dry out. Therefore, adding vinegar does not make meat dry faster.
- Vinegar does, however, help control the levels of microbes on biltong for at least a month after production. It therefore has an influence on shelf life.
Overall, it is useful to add vinegar in a spice formulation to ensure a consistent product that is safe for consumption.
- Drying rates depend on the type of meat muscle being used, and also the source of the meat.
Given the specific parameters used throughout the study, gemsbok topside took 76 hours to dry, fatty beef topside 118 hours, while beef topside and silverside both required about 96 hours to dry.
- Yeasts and moulds, which often cause a problem during storage, generally become visible after six weeks. Although not visible to the naked eye, they can already be present in high levels at the end of drying.
- Weight loss or adding vinegar does not influence the salt content of the dried meat.
- Beef biltong without vinegar has a pH of 5.56 to 5.75, while the addition of vinegar to biltong lowered its pH to 4.89 to 4.93, which prevents the growth of microbes.
Source: Stellenbosch University
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