Potential of plant-derived compounds to enhance the efficiency of conventional preservatives

Michaela Poslušná

Bachelor's thesis

Abstract:

The aim of the bachelor thesis was to evaluate the available data on the synergistic effect between conventional preservatives and plant-derived compounds. The literature search further discusses food preservation, conventional preservatives and their side effects, plant essential oils, their chemical composition, extraction methods, the use of essential oils as food additives and their effect on sensory properties, and a brief description of plant extracts. The most frequently used conventional preservative was nisin, which showed a synergistic effect with all the plant-derived compounds reported. The combination of nisin and plant-derived compounds, specifically rosemary extract, is both an alternative that allows the required dose of the preservative used alone to be reduced and also appears to be a potential solution to the problem of bacterial resistance. The thesis also attributes a possible alternative to milk preservation using nisin and its combination with cinnamaldehyde, citric acid and Ziziphora clinopodioides essential oil. Furthermore, the synergistic effect of lysozyme in fish preservation was confirmed, where the combination of lysozyme and pomegranate peel extract also displayed sensory acceptability and prolonged the acceptability of mackerel samples by an additional 6 days compared to untreated ones. Based on the evaluation of the available data, it can be confirmed that plant-derived compounds indeed enhance the efficiency of conventional preservatives, given that all combinations of preservatives and plant-derived compounds demonstrated a synergistic effect. Efficiency has been shown in different food models, varying from meat and meat products, milk, sauces and soup, carrot and sugar cane juice and fish to fresh strawberries or broccoli. Therefore, a great variety of potential uses of synergy for food preservation can be seen.

Keywords

conventional food preservatives, plant compounds, essential oils, synergy, enhancement, shelf life

Language used: English

Date on which the thesis was submitted / produced: 26. 4. 2023

Thesis defence

• Date of defence: 25. 5. 2023
• Supervisor: Ing. Pavel Nový, Ph.D.
• Reader: Jan Tauchen, Ph.D.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Bachelor programme:
Food and Nutrition