The Effect of Saccharomyces Strains and Fermentation Condition on the pH, Foam Property and CO2 Concentration of Non-alcoholic Beer (Ma-al-shaeer)

This study aims to determine the effect of fermentation condition and Saccharomyces strains on the pH, foam property and CO2 concentration of non-alcoholic beer (Ma-al-shaeer). For this, the beer samples were inoculated with four different species of Saccharomyces (Saccharomyces rouxii 70531, S. rouxii 70535, S. ludwigii 3447 and S. cerevisiae 70424) and fermented for 48h in both aerobic and periodic aeration at three different temperatures. Then their pH, CO2 concentration and foam property were analyzed in 12h intervals during 48h fermentation. The results shows that the treatments with 4×107 CFU.ml-1 and periodic aeration at 24˚C showed the greatest decrease in pH, and the treatments with 107 CFU.ml-1 and aerobic-periodic aeration at 4˚C showed the lowest decrease in pH. The highest and lowest amounts of CO2 and foam property were obtained in the treatments with 4×107 CFU.ml-1 inoculation, aerobic condition, and the treatments with 107 CFU.ml-1, periodic aeration, respectively. These results further demonstrated that the highest drop in pH, and the highest ability of producing CO2 and foam were for S. cerevisiae 70424, and the lowest belonged to S. rouxii 70531. The overall outcome of the study points to the fact that physico-chemical properties of Ma-al-shaeer is important from the consumers' point of view. Therefore, S. cerevisiae with 4×107 CFU.ml-1 inoculation and aerobic condition at 4˚C has promising potential for producing Ma-al-shaeer with good physicochemical properties

The Effect of Saccharomyces Strains and Fermentation Condition on the pH, Foam Property and CO2 Concentration of Non-alcoholic Beer (Ma-al-shaeer)

This study aims to determine the effect of fermentation condition and Saccharomyces strains on the pH, foam property and CO2 concentration of non-alcoholic beer (Ma-al-shaeer). For this, the beer samples were inoculated with four different species of Saccharomyces (Saccharomyces rouxii 70531, S. rouxii 70535, S. ludwigii 3447 and S. cerevisiae 70424) and fermented for 48h in both aerobic and periodic aeration at three different temperatures. Then their pH, CO2 concentration and foam property were analyzed in 12h intervals during 48h fermentation. The results shows that the treatments with 4×107 CFU.ml-1 and periodic aeration at 24˚C showed the greatest decrease in pH, and the treatments with 107 CFU.ml-1 and aerobic-periodic aeration at 4˚C showed the lowest decrease in pH. The highest and lowest amounts of CO2 and foam property were obtained in the treatments with 4×107 CFU.ml-1 inoculation, aerobic condition, and the treatments with 107 CFU.ml-1, periodic aeration, respectively. These results further demonstrated that the highest drop in pH, and the highest ability of producing CO2 and foam were for S. cerevisiae 70424, and the lowest belonged to S. rouxii 70531. The overall outcome of the study points to the fact that physico-chemical properties of Ma-al-shaeer is important from the consumers' point of view. Therefore, S. cerevisiae with 4×107 CFU.ml-1 inoculation and aerobic condition at 4˚C has promising potential for producing Ma-al-shaeer with good physicochemical properties

Viability of calcium alginate microencapsulated probiotic bacteria in Iranian yogurt drink (Doogh) during refrigerated storage and under simulated gastrointestinal conditions

The effects of microencapsulation of AB-type culture (Lactobacillus acidophilus LA-5 and Bifidobacterium lactis Bb-12) with calcium alginate on cell survival in Iranian yogurt drink (Doogh) during storage at 4°C for 42 days, as well as under simulated gastrointestinal conditions, were studied. The pH of the product at the beginning of storage was 4.53 and the final pH at the end of storage were 4.52 and 3.78 for the samples containing encapsulated and free cells, respectively. The acetic acid content in the encapsulated-cellcontaining Doogh increased by 0.01% (from 0.05 to 0.06%) during the storage period, whereas for free-cell-containing Doogh the increase was 0.04% (from 0.05 to 0.09%). At day 42, the viable counts of L. acidophilus and bifidobacteria in the samples containing encapsulated cells were 5.5 and 4.0 log cycles higher than those containing free cells, respectively. To evaluate the protective impact of encapsulation on cell survival in in vivo situations, the product was subjected to three simulated gastrointestinal conditions, including extreme conditions (pH 1.5, 90 min/2% bile, 90 min), intermediate conditions (pH 1.5, 90 min/1% bile, 90 min) and normal conditions, i.e. the situation in the gastrointestinal tract of a normal healthy person after the consumption of a probiotic-containing dairy drink, when the stomach has not been free for a relatively long time (pH 2.0, 30 min/0.6% bile, 60 min). The viability of the probiotic cells increased from 0.6% and 0.2% (L. acidophilus and bifidobacteria, respectively) as free cells to 18.0% and 9.5% under the extreme gastrointestinal conditions, after encapsulation. Under normal gastrointestinal conditions, the cell survival rates were 16.1% for L. acidophilus and 21% for bifidobacteria before encapsulation, and 26.3 and 34.0% (L. acidophilus and bifidobacteria, respectively) after encapsulation.Fil: Mortazavian ,A. M.. University of Medical Sciences and Health Services; IránFil: Ehsani, M. R. University of Tehran; IránFil: Azizi, A.. Food Engineering and Post-Harvest Technology Research Department; IránFil: Razavi, S. H.. University of Tehran; IránFil: Mousavi, S. M.. University of Tehran; IránFil: Sohrabvandi, S.. University of Tehran; IránFil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentin

Quality Attributes of Low-Alcohol Top-Fermented Beers Produced by Membrane Contactor

The practice of dealcoholization is used nowadays to reduce the alcohol content in beverages, and osmotic distillation seems to be a convenient membrane process due to its mild operating conditions. The focus is on the quality of final beverage which may lack in taste, flavor, and body. The aim of this work was to evaluate the quality attributes of low-alcohol beers, dealcoholized by osmotic distillation and using stripping solutions specific for the beverage composition. Two types of top-fermented beer were used: Weiss beer, with a very fruity aroma and strong phenolic content, and Bitter beer, with a malt aroma. Regarding the stripping solutions, they were obtained by dilution of the original beer with water, in order to limit the volatile compound loss during the process. Moreover, low-alcohol Weiss beer was also produced by using carbonated stripping solutions (i.e., saturated with CO2 at ambient pressure). The results highlighted that color, bitterness, total phenols, and antioxidant activity were unchanged in the low-alcohol beers but volatile compounds were reduced to a different extent. The lower vapor pressure of some volatile compounds (i.e., 2-phenylethanol, aldehydes) can explain their retention in beer. The carbonation of stripping solutions did not significantly reduce CO2 loss, but aldehydes and total alcohols were better retained in low-alcohol Weiss beer. Esters and other volatile compounds were reduced so that the low-alcohol beer may result with a weak sensory profile, which can be compensated by a re-addition of CO2 before bottling