m. a. razavi

Lactic acid bacteria are usually involved in the preparation of fermented foods and can produce different metabolites according to their strain type. The aim of this study was to evaluate the antimicrobial, antioxidant and aggregation activities of 10 different strains of Lactobacillus plantarum isolated from native fermented foods including Koozeh cheese, fermented olives, sourdough and camel milk. In this study, the antibacterial activity of 10 different strains of L. plantarum and their cell free supernatants against four pathogens were evaluated by agar-spot and well diffusion methods, respectively. The antifungal activity of the studied strains against two molds was investigated by overlay method. Additionally, auto-aggregation, co-aggregation and hydrophobicity tests of different strains were performed separately. The antioxidant activity of the strains and the cell free supernatants was also evaluated by the DPPH radical scavenging assay. The results showed that all strains had antimicrobial and antifungal activities against the indicator microorganisms and their activity level was different depending on the L. plantarum strains. Also, among the indicator pathogenic bacteria and molds, Escherichia coli and Aspergillus flavus, respectively were the most susceptible. The results of tests related to the surface cellular characteristics of the bacteria showed that the L. plantarum strains are very similar in terms of auto-aggregation, hydrophobicity and antioxidant properties. Indigenous L. plantarum strains and their metabolites can be suggested as a biopreservative in the food and drug industries, but more in-vitro and in-vivo tests should be carried out in this field.

In this study the rheological and physicochemical properties of four types of honeys, two poly floral (Mountain, Forest) and two mono floral (Sunflower, Ivy), were investigated. Rheological characteristics of honeys were evaluated at different temperatures (10, 15, 20, 25 and 30ºC). All the honeys exhibited Newtonian behavior for shear rate in the range of 1.045-41.8 s-1. The viscosity of samples varied between 1.70 and 270.48 Pa.s according to the kind of honey and the temperature of measurement. The temperature dependence of viscosity was described using the Arrhenius and the Vogel–Taumman–Fulcher (VTF) equations. The values of flow activation energy varied between 89.716 and 112.189 kJ/mol. Two models (Power Law and Exponential models) were also investigated to describe the concentration dependence of viscosity. The samples were found to be different from each other in moisture content, ºBrix, pH, ash, conductivity, free acidity, diastase activity, hydroxymethylfurfural content and sugar content values. The water content of honey samples was between 15.25–19.92 g/100 g.

Bread is the main source of a large part of the energy, protein, minerals and vitamins required by humans. Aloe Vera is one of the oldest medicinal plants that beside of fiber, minerals, vitamins, amino acids and natural sugars, have antimicrobial agents, anti-inflammatory and antioxidant Therefore, its use helpful for the prevention and treatment of Alzheimers, heart disease, digestive problems. This study examined the effect of addition of aloe vera powder in quantities of 1, 3, 6 and 9% (w / w based on flour) on the quality of bagette bread, as well as changes in microbial, texture, color and water absorption properties of bread within 72 hours in order to produce the functional bread. The results showed that the adding of aloe vera powder, causing controlling the activity of microorganisms and mold and yeast, increase swelling power and reduce staling the bread. However, volume, brightness, Points smell, taste and the ability to chewing has declined. In general, investigation of breads characteristics in this study showed that the adding powder of aloe vera until 1%, causing improve the quality of shelf life and increase the healthly value of bagette breads that is produced.