Jämförelse av olika konserveringsmedel genom belastningstest i ett flytande livsmedel

Translated title of the thesis: Comparison of different preservatives by challenge testing in liquid food
  • Elna Crona
  • Nathalie Johnsson

    Student thesis: Bachelor


    Introduction One third of food produced in the world is discarded (United Nations Development Program [UNDP], 2020) and food-destroying microorganisms are a common problem and a contributing cause of global food waste (Snyder & Worobo, 2018). The food industry therefore uses various hurdle techniques to minimize the risk of growth of spoilage organisms (Snyder & Worobo, 2018). One strategy to check whether different hurdle techniques meet their purpose is to expose foods in a challenge test.

    Aim The aim of the study was to compare the preservatives lingonberry juice and potassium sorbate + sodium benzoate and examine any physical and chemical changes over time through a challenge test on a liquid food product.

    Material and method A liquid food (n = 73 á 180 ml) was inoculated in a challenge test with log 2-3 microorganisms per ml food. Thereafter preservatives lingonberry juice (n = 24) or potassium sorbate + sodium benzoate (n = 25) were added. One third of the samples (n = 24) were left without preservatives. Sampling for analysis of growth, color, pH and viscosity (mPas) was performed at 0, 14 and 30 days after the food was inoculated with microorganisms.

    Results The results showed microbiological growth in all food products at day 0. Day 14 growth were found in the food with potassium sorbate + sodium benzoate and lingonberry juice. By the analysis on day 30 growth in the food with potassium sorbate + sodium benzoate and in the food without preservatives were showed. Over time physical changes of viscosity and chemical changes of pH occurred. Regard to color only marginal changes occurred.

    Conclusion The result of the challenge test showed that lingonberry juice is the preservative that has the best effect regard to product stability through inhibiting the added microorganisms. The results of the physical measurements showed changes regard to viscosity over time. Color only showed marginal changes. The result of the chemical measurement showed changes of pH over time.

    Date of Award2020-Aug-26
    Original languageSwedish
    SupervisorBetty Collin (Supervisor) & Arwa Mustafa (Examiner)

    Educational program

    • Culinary Arts and Food Sciences

    University credits

    • 15 HE credits

    Swedish Standard Keywords

    • Other Chemical Engineering (20499)


    • microbiological challenge testing
    • food spoilage
    • hurdle technology
    • clean label
    • natural preservatives
    • chemical preservatives

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