Rahil Rezaei; Morteza Khomeiri; Mahdi Kashani-Nejad; Mostafa Mazaheri Tehrani; Mehran Alami
Abstract
β-d- glucan as a soluble dietary fiber, has many desirable physical and physiological characteristic. In this research the effect of β-d- glucan and aging conditions (Time and Temperature) on some physicochemical and textural properties of frozen soy yogurt was investigated. Three variables ...
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β-d- glucan as a soluble dietary fiber, has many desirable physical and physiological characteristic. In this research the effect of β-d- glucan and aging conditions (Time and Temperature) on some physicochemical and textural properties of frozen soy yogurt was investigated. Three variables including concentration of oat β-d- glucan (0, 1 and 2%), aging time (2, 13 and 24 h) and aging temperature (2, 4 and 6°C) were studied. The results showed that the addition of β-d- glucan to frozen yogurt increased viscosity, overrun, hardness and fat destabilization but the melting resistance and L*value were decreased. In terms of aging conditions, it was revealed that increasing aging time could improve the quality of product whereas higher temperature had an undesirable effect on the quality of frozen soy yogurt. Longer aging time caused an increase in viscosity, hardness, fat destabilization and melting resistance. By increasing aging temperature, fat destabilization, overrun and viscosity were decreased and melting rate was increased. It was concluded that addition of β-d- glucan as a dietary fiber and prolonged aging time at low temperature could adjust textural properties of frozen soy yogurt and improve quality of this frozen dessert.
Rahil Rezaei; Morteza Khomeiri; Mehran Alami; Mahdi Kashani-Nejad
Abstract
In this study, effects of Guar and Arabic gum on the viability of two common probiotic, Lactobacillus acidophilus and Bifidobacterium lactis, in frozen yogurt during 60 days were investigated. Results of survival evaluation of probiotics showed that although during storage time bacteria counts decreased ...
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In this study, effects of Guar and Arabic gum on the viability of two common probiotic, Lactobacillus acidophilus and Bifidobacterium lactis, in frozen yogurt during 60 days were investigated. Results of survival evaluation of probiotics showed that although during storage time bacteria counts decreased significantly, this product could maintain 107 cfu/gr of probiotic at the end of storage. Maximum death rate of lactobacillus acidophilus was observed in control sample. Best viability of this microorganism was seen in samples containing 0.2% guar gum and 0.1% Arabic gum that these two treatments had no significant difference. The highest loss of bifidobacterium lactis belonged to sample containing 0.3% guar and lowest was seen in samples containing 0.1% Guar and 0.1% Arabic gum.
Maryam Ghaderi; Alireza Sadeghi Mahoonak; Mehran Alami; Morteza Khomeiri; Rahil Rezaei
Abstract
In this study, total phenolics and flavonoids content, antiradical and antimicrobial activity of methanolic extract of two Iranian acorn varieties, namely Quercus.castaneifolia var castaneifolia and Quercus.branti var persica were evaluated. Total phenolic and flavonoid content and extraction yield of ...
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In this study, total phenolics and flavonoids content, antiradical and antimicrobial activity of methanolic extract of two Iranian acorn varieties, namely Quercus.castaneifolia var castaneifolia and Quercus.branti var persica were evaluated. Total phenolic and flavonoid content and extraction yield of methanolic extract of castaneifolia variety (MC) were significantly higher than that of the extract of persica variety (MP). Extracts were also tested for their antioxidant activities using scavenging activity of 2, 2-diphenyl-1-picrylhydrazyl and compared with synthetic antioxidant namely BHA and BHT. EC50 values for MC, MP, BHA and BHT were 42.84, 70.40, 89.46 and 41.73 mg/ml, respectively. The extracts also showed good antimicrobial activity against all of tested microorganisms and the tested gram-negative bacteria was more resistant to the inhibitory effect of extracts. The ranges of minimum inhibitory concentration (MIC) of the extracts were 0.312-5 and 1.25-5 mg/ml for MC and MP, respectively. There was no difference between the MIC of MC and MB extract against Salmonella typhi and Shigella dysenteriae but MC extract showed the strongest activity on Escherichia coli and Yersinia entrocolitica at lower concentration. MP extract at concentration of 5mg/ml had bactericidal effect on all of gram negative bacteria (except Citrobacter). The most efficient bactericidal activity of MC extract was against Bacillus cereus, with MBC = 0.312 mg/ml while Shigella dysenteriae had the highest MBC (10mg/ml). A high-performance liquid chromatography was used for determination of phenolic acids of extracts. gallic, caffeic, p-coumaric and cholorogenic acid were found in MC and Gallic, caffeic, cholorogenic and sirinjic acid were detected in MP extract.
Keywords: Acorn fruit, Antimicrobial activity, Gallic acid, Methanolic extract, Phenolic Compounds
Soheil Amiri; Mehran Alami; Rahil Rezaei
Abstract
In the present research work, influence of fleawort (Plantago ovate L.) seed hydrocolloid at three concentration level (0.1, 0.15 and 0.2%) was investigated on physicochemical, textural and sensory characteristics of low fat yoghurt. The treated yoghurt samples were compared with a positive (3% fat) ...
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In the present research work, influence of fleawort (Plantago ovate L.) seed hydrocolloid at three concentration level (0.1, 0.15 and 0.2%) was investigated on physicochemical, textural and sensory characteristics of low fat yoghurt. The treated yoghurt samples were compared with a positive (3% fat) and negative (0.2%) control sample after 1, 7 and 15 days of storage. Fleawort seed hydrocolloid did not change the pH and titrable acidity of samples, significantly (p
