The effect of fresh and ripe Pistaciaatlantica on Shelf life and sensory properties of Iranian dough

Doogh is a kind of fermented beverage that are produced by mixing yogurt, water and little salt. The activity of yeast Kluyveromyces marxianus can cause major problems, such as the creation of gas in it during the storage period. The essence of mountain pistachio (Pistacia atlantica) fruit has shown effective antimicrobial properties in the vitro. This study aims to investigate the effect of mountain pistachio fresh and ripe fruit essences on viability of Kluyveromyces marxianus in Iranian Doogh. for this reason, Pistacia atlanticafresh and ripe fruit essencewas abstracted using distillation (with water) method with Clevenger design. Effective compositions of essence was identified through gas chromatography apparatus equipped with mass spectrometer (GC/MS).Inhibitory influence of Pistacia atlanticafresh and ripe fruit essence has been studied on Kluyveromyces marxianus in Iranian Doogh at % 0.05, %0.1,% 0.125, %0.25 concentrations under 4 °C during 28-days period after storage.Findings showed that fresh and ripe fruit essences of Pistacia atlanticahas the highest Inhibitory effect on Kluyveromyces marxianus growth at higher concentrationsconcentration of essence. This concentration caused to significant decline in inoculated yeast number (P<0.5) at 4 °C.Concerning the effect of essential oils on organoleptic properties and antimicrobial effects, it can be said that the optimum concentration that produced the taste was 0.1% of essential oil, which resulted in a significant decrease (p <0.05) in the number of yeast .