Comparing microbiological profiles, bioactivities, and physicochemical and sensory properties of donkey milk kefir and cow milk kefir

Abstract

Consumption of fermented milk products especially kefir is accelerated in the population due to their high nutritional value and other health benefits. These health benefits are rooted in the composition of source material and flora of kefir grains. Therefore, the utilization of different kinds of milk as source material in kefir production directly affects the properties of kefir. In this study, changes in the physicochemical properties, microbiological profiles, antibacterial effects, antioxidant activities, sensory evaluation, and total phenolic and total flavonoid contents of kefirs obtained from donkey milk (DM) and cow milk (CM) were compared. It was found that donkey milk kefir (DMK) and cow milk kefir (CMK) have different physicochemical properties and microbiological profile. DMK showed antibacterial activity against seven bacterial strain used in this study. The antioxidant activity was increased with fermentation in both kefir samples. The total phenolic content of DMK was higher than that of CMK whereas the total flavonoid content of CMK was higher than that of DMK. Sensory analysis showed that participants prefer CMK to DMK. It can be concluded that with its higher flavonoid content and antibacterial activity, DMK might be an alternative nutrient for consumers.

Bioactive Compounds from Kefir and Their Potential Benefits on Health: A Systematic Review and Meta‐Analysis

“…Donkey milk kefir reduced Klebsiella pneumoniae , Bacillus cereus , and Proteus mirabilis by 8%, 37%, and 58% compared to the kanamycin antibiotic. In contrast, cow milk kefir decreased B. cereus by 12.9% while had the same impact on Proteus mirabilis compared to kanamycin, demonstrating the tremendous antimicrobial potential associated with lactic acid [ 60 , 66 ]. However, there was no antimicrobial effect against Pseudomonas aeruginosa [ 17 , 60 ].…”

“…In contrast, cow milk kefir decreased B. cereus by 12.9% while had the same impact on Proteus mirabilis compared to kanamycin, demonstrating the tremendous antimicrobial potential associated with lactic acid [ 60 , 66 ]. However, there was no antimicrobial effect against Pseudomonas aeruginosa [ 17 , 60 ]. Other organic acids present in kefir, such as acetic and pyruvic acid, also demonstrated an antimicrobial effect when administered together with lactic acid [ 14 , 31 , 70 ].…”

In-Vitro Investigation of Donkey Milk Efficacy Against Standard Staphylococcus Aureus Strains

“…When the studies examining the antimicrobial activity of donkey milk against S. aureus were checked; In a study conducted by Yirmibeşoğlu and Öztürk in 2020 they examined the zone diameters of donkey milk-impregnated discs against S. aureus, they found this zone diameter to be 11,5 mm, and the ampicillin zone diameter they added for control purposes was 22 mm [7]. In Koutb et al's study in 2016, they found that donkey milk-impregnated discs formed a zone diameter of 18 mm against S. aureus ATCC 8095, and the minimum lethal concentration was 64 when they examined it [8].…”

“…Control of MRSA is still an important problem in hospitals [5]. In some studies, it has been reported that donkey milk have different levels of antimicrobial activity against S. aureus strains [7,8]. Therefore, we aimed to examine the effectiveness of different dilution rates of donkey milk against S. aureus strains, which is an important problem all over the world, and to determine the antimicrobial effect of standard MRSA and MSSA strains in-vitro [8,9].…”

Muğla İlinde Üretilen Eşek Sütlerinin Cu, Fe, Mn ve Zn Element İçerikleri

“…Günümüzde eşek sütünün sağlık açısından kabul kriterleri bulunmadığından, eşek sütü üretiminin standartlaştırılması, ürün kalite kontrolünün güçlendirilmesi, tüketici ve işletmelerin haklarının korunması için uygun standartların belirlenmesi gerekmektedir. Son yıllarda eşek sütü ve ürünlerinin (kefir vs.) mikrobiyolojik profili ve riskleri, biyoaktiviteleri ve fizikokimyasal özellikleri ile ilgili yapılan çalışmalar artsa da endüstrisinin gelişimini sağlayacak verilerin toplanması adına daha fazla çalışmanın yapılması gerekmektedir [3,[7][8][9][10].…”