Microbial growth inhibition by the use of selected plant powders in minced meat
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Kuupäev
2025
Kättesaadavus
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Estonian University of Life Sciences
Abstrakt
This study aimed to evaluate the microbial growth inhibition effect of plant powders in minced pork and beef. Additionally, polyphenolic profiles of the plant powders were determined. Pomace powders of berries of blackcurrant, chokeberry, rowan and tomato were used. Additionally the powders of petioles of rhubarb, bulbs
of garlic and apples were used. Apple powders were whole apples and apples without seeds. Plant material was
dried at 50 °C, then the dried material was milled into a fine powder using a grinder and finally sieved to obtain a
fraction of ≤1 mm. The plant powder was added at 2% (w/w) of the minced meat. Fresh minced pork with 28%
fat content and minced beef with 18% fat content were used. The minced meats were purchased from a large-scale
Estonian meat industry. The total phenolic content of the plant powder extracts in 60% aqueous ethanol was
measured spectrophotometrically using the Folin–Ciocalteu method. Two percent of plant powders were added to
the minced meats, and a mixer was used to ensure the plant powders were thoroughly incorporated. Pure minced
meat was used as the control. The samples were packed in sterile screw-top cups and stored in the refrigerator at
4 ± 2 °C. All analyses were performed in duplicate on days 1, 4, 6, and 8, with additional analyses on days 11 and
14 for the rhubarb samples, which exhibited strong inhibition of microbial growth. Enumeration of aerobic
mesophilic microorganisms, yeasts and moulds and presumptive Pseudomonas spp. was performed according to
the ISO standards. At all time points, an estimation of pH and water activity was performed. We found that rhubarb
powder in minced meat reduced the average total microbial counts by 10-fold, and the counts of Pseudomonas
spp., yeasts, and molds by 100-fold compared to the control. Also, samples containing powders, such as
blackcurrant, garlic, tomato and chokeberry showed lower total microbial counts than the controls. The low
microbial growth inhibition effect was found for rowan berry pomace and apple powders in minced meat. Apart
from organic acids, 27 distinct polyphenolic compounds from the classes of anthocyanins, dihydrochalcones,
flavanols, flavonols, and hydroxycinnamic acids were tentatively identified in the plant powders. The highest
number of polyphenolic compounds (n = 20), were found in blackcurrant, chokeberry and rowan berry powders,
followed by rhubarb powder, which contained 16 different compounds. In the present study, rich composition of
polyphenols was found in blackcurrant, which also showed good inhibition of microbial growth in enriched
minced pork and beef samples. The lower pH and the presence of organic acids in samples can explain the best
microbial growth inhibition effect of rhubarb powder. We suggest that plant powders with a rich composition of
polyphenols can be applied for the valorization of different foods, both animal and plant-based food products.
Kirjeldus
Märksõnad
plant powders, polyphenols, antimicrobial effect, valorization, food processing, abstracts