Volume: 1, 2022
1st International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: T041
DOI: https://doi.org/10.24326/ICDSUPL1.T041
Published online: 26 April 2022
ICDSUPL, 1, T041 (2022)
The effect of nettle addition on physicochemical, microbiological and sensory changes in yoghurts made on the basis of organic cow milk
Joanna Wajs1* and Aneta Brodziak1
1 Department of Quality Assessment and Processing of Animal Products, Faculty of Animal Sciences and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland
* Corresponding author: joanna.wajs@up.lublin.pl
Abstract
Yoghurts are classified as functional foods. They are characterized by high digestibility and bioavailability. The proteins, minerals, vitamins, lactic acid, peptides and free fatty acids they contain have a positive effect on the body, e.g. by strengthening resistance or alleviating the symptoms of digestive system diseases. In order to increase the attractiveness of phenolic-poor yoghurts, they are enriched with various additives, including herbs. Therefore, the aim of the study was to evaluate the physicochemical, microbiological and sensory changes in yoghurts produced with the addition of nettle powder (Urtica dioica L.), based on organic cow’s milk. For the tests, bulk milk was collected from Simmental cows kept on an ecological farm, which was subjected to thermal treatment (85 ° C, 30 min). The yoghurts were made using the thermostat method. Nettle powder (Holistic Nassla) was used in amounts of 5 and 10%. The traditional yoghurt vaccine (YC-X11, ChR Hansen) and the probiotic ABT-1 vaccine were used as a starter culture. The control group consisted of yoghurts without added nettle. The powder was also assessed (nutritional value and microbiological quality). The acidity, water activity, basic nutritional value, calorific value, content of selected bioactive compounds (whey proteins, lipophilic vitamins, vitamin C, polyphenolic compounds and amino acids), total antioxidant status, microstructure and microbiological and sensory properties were determined. The results were statistically calculated (Statistica ver. 13.1, Dell Inc.). It was shown that regardless of the addition, the mean pH value was 4.65, and the lactic acid content was not less than 0.70%. Yoghurts with the addition of nettle, regardless of the type of breeding, were characterized by significantly higher water activity (0.81) compared to the control (0.73). The addition of nettle increased the nutritional value, including protein and carbohydrate content. Yoghurts with 5% nettle contained an average of 3.48 g / 100 g of fiber, and in 10% – 5.12 g / 100 g. Among phenolic compounds, p-hydroxybenzoic acid and vanillin were detected. ABT-1-based yoghurts with nettle showed significantly lower (p≤0.01) hardness, cohesive strength and adhesion. The vitamin C content in the analyzed yoghurts was on average 7.53 mg / 100 g. The products had an appropriate microbiological quality. When making a sensory assessment, the tasters indicated that the addition of 5% was optimal and better suited to their tastes – regardless of the type of starter culture, the yoghurts obtained scores above 4 points / 5 points. max. Summing up, it should be stated that the addition of nettle is an interesting alternative in the production of yoghurt and research in this area should be continued.
Project financed under the program of the Minister of Science and Higher Education under the name “Regional Initiative of Excellence” in 2019-2022 project number 029/RID/2018/19 funding amount 11 927 330.00 PLN
How to cite
J. Wajs, A. Brodziak, 2022. The effect of nettle addition on physicochemical, microbiological and sensory changes in yoghurts made on the basis of organic cow milk. In: 1st International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL1/T041