Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt

<strong>Introduction:</strong> The demand for antimicrobial compound alternatives to replace synthetic additives is on the rise. In food commodities, use of synthetic antimicrobials based on herbal extracts is attracted attention. The present study aimed to assess the chemical, microbiol...

Full description

Bibliographic Details
Main Authors: Yasser Shahbazi, Nassim Shavisi
Format: Article
Language:English
Published: Mashhad University of Medical Sciences 2019-09-01
Series:Journal of Fasting and Health
Subjects:
Online Access:http://jnfh.mums.ac.ir/article_13358_46a479e3394013b19c283b8abcc74bb8.pdf
_version_ 1818694085181964288
author Yasser Shahbazi
Nassim Shavisi
author_facet Yasser Shahbazi
Nassim Shavisi
author_sort Yasser Shahbazi
collection DOAJ
description <strong>Introduction:</strong> The demand for antimicrobial compound alternatives to replace synthetic additives is on the rise. In food commodities, use of synthetic antimicrobials based on herbal extracts is attracted attention. The present study aimed to assess the chemical, microbiological, and sensory properties of the yogurt samples treated with oregano extract (0%, 0.75%, 1%, and 1.5%) during storage for 30 days at refrigerated temperature. <strong>Methods:</strong> The in-vitro antibacterial effect of oregano extract was evaluated using agar disk-diffusion assay. Natural yogurt was prepared using a combination mixture of whole milk and 4% skimmed milk powder. Various concentrations of the oregano extract (0%, 0.75%, 1%, and 1.5%) were added to the samples. During 30 days of refrigerated storage, various parameters were evaluated, including titratable acidity, pH, mold and yeast counts, total coliforms, and sensory attributes (overall liking, appearance, and aroma). <strong>Results:</strong> The descending order of the in-vitro antibacterial effect of the oregano extract was as follows: Listeria monocytogenes>Staphylococcus aureus>Bacillus subtilis>Bacillus cereus>Salmonella typhimurium>Escherichia coli O157:H7. Differences were observed in the counts of mold and yeast in the samples over time. Accordingly, bioactive yogurt had lower mold and yeast counts (1-1.5 log CFU/g) after 30 days of storage compared to the control (P<0.05). In addition, significant differences were observed in the hedonic scores of aroma and appearance between the samples containing the oregano extract compared to the control group (P<0.05). <strong>Conclusion:</strong> According to the results, oregano extract could be used as a natural compound to improve the shelf life of yogurt at refrigerated temperatures for 30 days. Furthermore, oregano extract is considered to be an effective inhibitory compound against L. monocytogenes, S. aureus, B. subtilis, B. cereus, S. typhimurium, and E. coli O157:H7.
first_indexed 2024-12-17T13:23:58Z
format Article
id doaj.art-f4772e3408904959a1e02995866c5abb
institution Directory Open Access Journal
issn 2345-2587
2345-2587
language English
last_indexed 2024-12-17T13:23:58Z
publishDate 2019-09-01
publisher Mashhad University of Medical Sciences
record_format Article
series Journal of Fasting and Health
spelling doaj.art-f4772e3408904959a1e02995866c5abb2022-12-21T21:46:48ZengMashhad University of Medical SciencesJournal of Fasting and Health2345-25872345-25872019-09-017313814510.22038/jnfh.2019.39732.118913358Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of YogurtYasser Shahbazi0Nassim Shavisi1Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Razi University, Kermanshah, IranDepartment of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Razi University, Kermanshah, Iran<strong>Introduction:</strong> The demand for antimicrobial compound alternatives to replace synthetic additives is on the rise. In food commodities, use of synthetic antimicrobials based on herbal extracts is attracted attention. The present study aimed to assess the chemical, microbiological, and sensory properties of the yogurt samples treated with oregano extract (0%, 0.75%, 1%, and 1.5%) during storage for 30 days at refrigerated temperature. <strong>Methods:</strong> The in-vitro antibacterial effect of oregano extract was evaluated using agar disk-diffusion assay. Natural yogurt was prepared using a combination mixture of whole milk and 4% skimmed milk powder. Various concentrations of the oregano extract (0%, 0.75%, 1%, and 1.5%) were added to the samples. During 30 days of refrigerated storage, various parameters were evaluated, including titratable acidity, pH, mold and yeast counts, total coliforms, and sensory attributes (overall liking, appearance, and aroma). <strong>Results:</strong> The descending order of the in-vitro antibacterial effect of the oregano extract was as follows: Listeria monocytogenes>Staphylococcus aureus>Bacillus subtilis>Bacillus cereus>Salmonella typhimurium>Escherichia coli O157:H7. Differences were observed in the counts of mold and yeast in the samples over time. Accordingly, bioactive yogurt had lower mold and yeast counts (1-1.5 log CFU/g) after 30 days of storage compared to the control (P<0.05). In addition, significant differences were observed in the hedonic scores of aroma and appearance between the samples containing the oregano extract compared to the control group (P<0.05). <strong>Conclusion:</strong> According to the results, oregano extract could be used as a natural compound to improve the shelf life of yogurt at refrigerated temperatures for 30 days. Furthermore, oregano extract is considered to be an effective inhibitory compound against L. monocytogenes, S. aureus, B. subtilis, B. cereus, S. typhimurium, and E. coli O157:H7.http://jnfh.mums.ac.ir/article_13358_46a479e3394013b19c283b8abcc74bb8.pdfOregano extractYogurtShelf life
spellingShingle Yasser Shahbazi
Nassim Shavisi
Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt
Journal of Fasting and Health
Oregano extract
Yogurt
Shelf life
title Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt
title_full Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt
title_fullStr Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt
title_full_unstemmed Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt
title_short Effects of Oregano Methanolic Extract on the Chemical, Microbial, and Sensory Properties of Yogurt
title_sort effects of oregano methanolic extract on the chemical microbial and sensory properties of yogurt
topic Oregano extract
Yogurt
Shelf life
url http://jnfh.mums.ac.ir/article_13358_46a479e3394013b19c283b8abcc74bb8.pdf
work_keys_str_mv AT yassershahbazi effectsoforeganomethanolicextractonthechemicalmicrobialandsensorypropertiesofyogurt
AT nassimshavisi effectsoforeganomethanolicextractonthechemicalmicrobialandsensorypropertiesofyogurt