تقييم النشاط المضاد للبكتيريا والمضاد للأكسدة لمشروبات المعينات الحيوية المخمرة بحبوب الكفير

Abu Jahle, Khadija Jebril (2019) تقييم النشاط المضاد للبكتيريا والمضاد للأكسدة لمشروبات المعينات الحيوية المخمرة بحبوب الكفير. Masters thesis, الجامعة الإسلامية – غزة عمادة البحث العلمي والدراسات العليا -كلية العلوم- ماجستير العلوم الحياتية.

[img] Text
127950.pdf

Download (4MB)

Abstract

Background: Recent years showed developing in the use of functional food for their importance in improvement public health this including probiotic food from nature sources .kefir well known as probiotic use to ferment many types of milks for many years ago. Nowadays, many studies focused on its benefits in enhancement health by its antimicrobial activities and antioxidant properties. Objective: The main objective of this study is to evaluate antibacterial and antioxidant activities of probiotic beverages inoculated with kefir grains. Methodology: The fermented milks and fruit juices with kefir grains have been studied for their activity against some clinically isolated bacteria. Three type of milk cow, goat and soya milk were fermented for 24 h , while seven types of fruits juices were fermented by kefir grains for 48h including Psidium guajava ,Actinidia chinensis, Punica granatum, Fragaria ×ananassa, Daucus carota, Saccharum officinarum and Malus domestica . Before fermentation apple juice was mixed with whey then adjust brix value to14oBx. The antibacterial activities of beverages were tested using the disk diffusion method and well diffusion method; the inhibitory zones were recorded in millimeters. The minimal inhibitory concentration (MIC) was tested using microdilution method. The synergistic effect between fermented beverages and antibiotics was assessed using disk diffusion method. Clinical isolated bacteria used in the study were Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, klebsiella pneumoniae and Bacillus subtilis. Also antioxidant activity including: reducing power activity, ferrous ion chelating effect and inhibition ascorbate autoxidation were carried out. Results: The results of well diffusion method showed more effective than the diffusion through the disc. The well diffusion results indicated that the average diameter of the inhibition zones against the tested bacteria caused by the effect of fermented beverages ranged between 7.33-20.33 mm, 8-18 mm, 7.66-19.66 mm, 9-21.66 mm, 7.66-21.33 mm for B. subtilis, S. aureus, K. pneumoniae, P. aeruginosa and E. coli respectively. The lowest inhibitory concentration of these fermented beverages showed a clear activity against bacteria as the average results showed that fermented pomegranate juice with kefir gave the best inhibitory concentration. Also, fermented beverages when combined with antibiotics were found to have a different synergistic effect against selected strains. Antioxidant results showed that these drinks have the ability to reduce ferric/ferricyanide complex to the ferrous form also chelating ferrous ion and inhibition ascorbate autoxidation were recorded with different activities . Conclusion: Most of the studied probiotic beverages showed the ability to inhibit bacterial growth. In addition, antioxidant results showed promising results for reducing risk of many diseases. Further studies are required to determine the active components and more antioxidant properties. Key words: kefir grains, probiotic, antioxidant, antibacterial, synergistic effect

Item Type: Thesis (Masters)
Subjects: Q Science > Q Science (General)
Depositing User: أ. دارين علي أحمد حمد
Date Deposited: 23 Nov 2020 11:22
Last Modified: 23 Nov 2020 11:22
URI: http://scholar.alaqsa.edu.ps/id/eprint/2625

Actions (login required)

View Item View Item