Hajar Shahsavar; Marzieh Bolandi; Homa Baghaei
Abstract
Introduction: Plant extracts have antimicrobial properties and can be substituted as chemical flavorings in food. Preservatives are compounds that are used to inhibit the growth or to eliminate harmful microorganisms to increase the shelf life of foods. Nowadays, the use of natural preservatives derived ...
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Introduction: Plant extracts have antimicrobial properties and can be substituted as chemical flavorings in food. Preservatives are compounds that are used to inhibit the growth or to eliminate harmful microorganisms to increase the shelf life of foods. Nowadays, the use of natural preservatives derived from medicinal plants is increasing due to their greater compatibility and the presence of volatile compounds (Celiktas et al., 2007). The antimicrobial properties, antioxidant and anticancer effects of these natural additives have been proven (Tajkarimi et al., 2010). In this study, the antimicrobial activity enhancement effect of the combination of hydroalcoholic extracts of basil, cinnamon and salvia on Escherichia coli, Staphylococcus aureus and Saccharomyces cerevisiae yeast in Iranian yoghurt drink (doogh) was investigated for 4 weeks at ambient temperature. Materials and Methods: The milk was boiled in hygienic conditions at 95 ° C for 5 min. After cooling to 45 ° C, they were inoculated. The aerial parts of the studied plants were milled and powdered. Cinnamon, basil and salvia extracts were then soaked. The food strains of Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 700728 and Saccharomyces cerevisiae PTCC 5193 were prepared as lyophilized ampoules. The microdilution broth method was used to determine the minimum inhibitory concentration. The minimum bactericidal concentration (MBC) was determined in accordance with the minimum inhibitory concentration (MIC) results. To determine the antimicrobial effect of the extracts on the yoghurt drink, 9 ml of the prepared yoghurt drink was poured into each test tube. Then 1 cc of each extract and 1 cc of microbial suspension (1.5 × 108 CFU / ml) were added. One tube was considered as positive control (bacteria + yoghurt drink), one negative control tube (extract + yoghurt drink) and one control tube (yoghurt drink only) and the tubes were placed at ambient temperature. Then, on day 7, 14, 21 and 30 during storage, 20 µl of each tube, were cultured on Muller Hinton agar medium and the same amount of yeast was cultured on blood agar medium. After incubation for 24 h at 37 ° C, the colonies were counted. The interaction of antimicrobial activity of the combination of basil, cinnamon and sage extracts was evaluated on the basis of differential inhibitory concentration index (FIC). Results and discussion: The results showed that the minimum inhibitory concentration of the combined basil, cinnamon and sage extracts against Staphylococcus aureus and Saccharomyces cerevisiae and Escherichia coli were 0.4, 0.4 and 3.12 mg / ml, respectively. Also, Staphylococcus aureus was more susceptible to the extracts, which were used alone, and was inhibited by a lower concentration of used extract (Ahmadi et al., 2018). However, due to the maximum minimum inhibitory concentration (MIC), Escherichia coli was less sensitive to the extracts which was used alone. The combined usage of all three extracts significantly reduced the maximum minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC), indicating that their antimicrobial activity was more effective against the studied microorganisms than each of the extracts which was used alone. The results of this study showed that synergistic effect against Staphylococcus aureus and Saccharomyces cerevisiae was more effective with the combination of the aforementioned extracts (p <0.05). The results of the Escherichia coli population counting during storage indicated that most of the extracts had a good effect on preventing the growth of Escherichia coli in the doogh environment compared to the control sample (p <0.05). Addition of the extract significantly prevented pH reduction over time (p <0.05), so that the control sample had the highest and the sample containing all three extracts showed the lowest pH changes over time (p <0.05). Therefore, it can be concluded that acid production by Lactobacillus bacteria in samples containing extract during storage period was higher than control. The results of this study were in agreement with the results of Mortazavian et al., (2007) and Voosogh et al., (2009). The acidity of the doogh samples increased significantly over time (P<0.05), while the addition of the extract significantly prevented the acidity increase over time (P<0.05). Sensory properties are the main factors of acceptance and satisfaction of many products. In this study, the mean viewpoint of doogh samples containing the combination of the three above mentioned extracts in terms of taste, odor, color and general acceptance are acceptable. Additionally, it was found that about 90% of participants were willing to use it. Although studies of the overlapping or synergistic effects of medicinal plant extracts in real food environments are not extensive, their results have shown that, the addition of different medicinal plants compounds can increase antibacterial effects. Therefore, the simultaneous use of these extracts can be used in effective control of food pathogens as a complementary method. The results of this study were in agreement with the results of Karimi (2007).
Homa Baghaei; Mohammad Javad Varidi; Mehdi Varidi
Abstract
Determination of the body composition weight due to the growing ostrich farms in Iran is a beneficial subject. It is so important for dependent industries to know the effects of sex and slaughter conditions on carcass quality. In present study, the mean value for hot yield (55.93%) was higher than cold ...
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Determination of the body composition weight due to the growing ostrich farms in Iran is a beneficial subject. It is so important for dependent industries to know the effects of sex and slaughter conditions on carcass quality. In present study, the mean value for hot yield (55.93%) was higher than cold yield (54.70%). Blood, feather and skin were evaluated as the maximum and the hide as the minimum body weight parts. Effect of sex on the body composition weight was insignificant (p>0.05). The mean value for cooling loss in carcasses was 2.2% that did not influence by sex significantly (p>0.05). The average values for drip loss in 1 and 7 days of postmortem were 1.52% and 1.68% respectively. The mean value for cooking loss in male and female ostriches were calculated 31.85% and 33.55% respectively while this parameter in stunned ostriches were evaluated 33.30% and in non-stunned one were 32.10% (p>0.05). Although drip and cooking losses increased during 14 days, there were no significant effects of ageing, sex and slaughter conditions (p>0.05).
Homa Baghaei; Farimah Aghaei; Nasser Sedaghat; Mohebbat Mohebbi
Abstract
In view of the importance environmental pollution caused by plastic food packaging, in recent years there is a considerable interest in edible films and coating based on polysaccharides, proteins, lipids or combination of them. Edible coatings also serve as carriers of food additives such as anti-browning ...
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In view of the importance environmental pollution caused by plastic food packaging, in recent years there is a considerable interest in edible films and coating based on polysaccharides, proteins, lipids or combination of them. Edible coatings also serve as carriers of food additives such as anti-browning and antimicrobials agents, colorants, flavor, nutrients and spices, so act as active packaging. In this study, effect of garlic essential oil )0.5%, 1.5%, 2.5% w/w of film solution) on isolated soy protein films was investigated by measuring changes in properties including antimicrobial activity against (Escherichia coli H7:0157, Salmonella enteritidis and Staphylococcus aureus), mechanical (tensile strength, elongation at break), physical (transparency, water vapor permeability, microstructure) and sensory (chewing, apparent and odor). Incorporation garlic oil improved mechanical and water vapor permeability properties and decreased transparency, structure and organoleptic attributes (p
Elnaz Milani; Homa Baghaei; Seyed Ali Mortazavi
Abstract
Yog-ice cream (Frozen yogurt), is a kind of frozen dessert which has similar features to ice cream in physical and appearance characteristics. Recently, there has been a growing interest in using frozen yogurt due to existence of lactic acid bacteria & fermentation processing. Besides, yog-ice cream ...
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Yog-ice cream (Frozen yogurt), is a kind of frozen dessert which has similar features to ice cream in physical and appearance characteristics. Recently, there has been a growing interest in using frozen yogurt due to existence of lactic acid bacteria & fermentation processing. Besides, yog-ice cream contains lower levels of sugar, fat & emulsifiers than ice cream. This Research was conducted to examine the effect of date syrup with different concentrations (0, 25 and 50% as a sugar replacement) & guar gum addition (0, 0.1, 0.2 & 0.3% as a fat replacer) on rheological properties of low fat orange yog-ice cream. The results showed that by increasing the date syrup and guar concentration, the viscosity of mixture increased but overrun decreased significantly in all samples (p< 0.05). Results for stickiness of the yog-ice cream samples indicated that the low fat yog-ice cream was considerably less adhesive/sticky than both low fat product containing guar and date syrup. Hardness of low fat yog-ice cream samples was observed to be considerably higher than the samples with guar and date syrup, whilst the addition of guar and date syrup up to 0.3% & 25%, decreased the hardness of the low fat product.
Keywords: Low-fat yog-ice cream, Guar, Dates syrup, Rheological properties
