In the present study the amount of whey protein to casein ratio (W/C ratio) (0.22-0.7), fat content (FC) (0.5-1.5%) and microbial transglutaminase (mTGase) (0.0-1.0 U/g substrate protein) in the formulation of low fat set type yoghurt, prepared from reconstituted milk, were optimized by response surface method to achieve the best rheological properties and sensory characteristics. The selected parameters consisted of higher consistency coefficient, consistency, texture and mouth feeling and lower syneresis and pH. The optimum condition was found to be 0.97, 0.46 and 0.5% of the enzyme concentration, W/C ratio and FC respectively. Results showed that thermal denaturation increased up to 33% with increasing W/C ratio significantly. All samples showed non-Newtonian shear thinning behavior. Increasing in W/C ratio from 0.22 to 0.7 raised the consistency coefficient, yield stress and textural parameters such as hardness and consistency of yoghurt. Enzyme addition (together with starter culture addition) increased yoghurt viscosity and yield stress. In sensory evaluation W/C ratio affected the texture and mouth feeling of yoghurt samples and the influences of FC and mTGase were not significant. Yoghurt syneresis was highly affected by FC, W/C ratio and mTGase.

The objective of this study was to determine the anti-yeast effect of Lactobacillus spp. isolated from two popular iranian cheeses known as Lighvan and Motal against food spoilage yeasts known as Rhodotorula mucilaginosa, Saccharomyces cerevisiae and Kluyveromyces lactis. twenty strains of Lactobacillus were selected from Motal (16 isolates) and Lighvan cheeses (4 isolates). Anti-yeast activity was studied by Agar Spot and Well Diffusion Assay. Effect of pasteurization on inhibitory compounds was also investigated. Results showed that two strains of Lactobacillus brevis (M4 and M2) exhibited the highest anti-yeast activity in aforementioned methods, as well as tolerated pasteurization. M4 and M2 strains were inoculated into Doogh (a fermented yogurt drink) at two levels (10 6 and 10 8 cfu/ml). All samples were incubated in three storage temperatures (4, 25 and 37 °C) and were then examined for microbial parameters (Mold and yeast counts, coliform, E. coli and Staphylococcus aureus) at specific intervals. Sample with M4 (10 6 cfu/ml) showed superiority rather than control sample in microbial point of view. At temperatures of 25 and 37 °C, inoculated samples were not contaminated up to day-21 and day-14, respectively. The propionic acid content for M4 and M2, was 14576.11 and 11697.3 ppm, respectively. Results indicate that incorporation of strain M4 (Lb. brevis) at a level of 10 6 cfu/ ml can potentially postpone the yeast spoilage in Doogh and prolong the stability of this product. in conclusion, these strains had the highest activity against experimented yeasts. Fermented commodities present a crucial effect in human dietary all over the world owing to their beneficial effects on health. Fermentation is one of the ancient and most commercial approach applied for food preservation. The primary precedent exhibit that mankind was consuming 'acidified or fermented milk' dated to about 2000 years ago 1. Yogurt drinks are known in the Middle East with various titles such as Lassi, Doogh, Yogurt and Ayran, and in Scandinavian countries, as acidophilus milk, Viili (a ropy, fermented milk that originated in Scandinavia, which is claimed to have various functional benefits and health-improving potential which is popular in Finland), 2. Doogh is a fermented dairy product that is obtained from the mixing of yogurt with water and some other additives such as salt and mint 2. Presently, Doogh has gained acceptable popularity and wide consumption in Iran and per capita consumption as well as industrial production has achieved noticeable growth in recent years. Acceptability of Doogh is not only related to the desirable sensory attributes but also to healthy fermented drink which make it accepted as national drink in Iran. Doogh has also gained high popularity in other countries according to the literature 3. Fungal spoilage of food and feed is a universal issue. It has been estimated that almost 5-10% of world food production is lost as a result of fungal spoilage with economic losses 4. Furthermore, the growth of particular f...

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The baking industry is interested in finding cost‐effective and healthful alternatives for eggs. Therefore, in this study the effects of total replacement of egg by soymilk (SM) in combination with 0–6% soy lecithin (SL) on batter (density, microstructure, viscosity, and texture) and cakes (height, volume, density, texture, color parameters, and sensory attributes) were determined and compared with cakes manufactured with eggs. The results showed that all batters had shear thinning behavior and provided a good fit for the power law model. The egg‐free cake in the absence of SL was downgraded because of high density and viscosity, small air bubbles, dark color, firm texture, low volume, and sensory scores. Inclusion of up to 4% SL to the SM was found to be significant in improving cake quality and led to cakes more similar to the control sample; however, higher levels of SL had negative effects on organoleptic properties of cakes.

The aim of this study was to investigate the structural, physicochemical, and rheological properties of soy and sesame milk‐based ice cream in order to optimize its formula. The overrun percentage of the optimized ice cream was acceptable compared to the conventional ice cream (produced with cow milk). The hardness and consistency of the optimized ice cream were significantly (p < .05) higher than those of the conventional one, while its cohesiveness was lower. All the samples showed the pseudoplastic behavior and the power‐law model had a high efficiency (R2 ≥ .99) in describing their rheological behavior. The lowest span value, the lowest mean particle diameter, and the highest mean particle surface area, and thus, the most stable and homogenous samples were associated with the conventional ice cream followed by the optimized plant one. The number of air bubbles in the structure of the conventional and optimized ice creams was significantly (p < .05) higher than in the other samples. The soy ice cream had the lowest Tg (−58.04°C), whereas the conventional one had the highest Tg (−55.05°C). Unlike the plant‐based samples, especially the soy ice cream, the conventional ice cream had the lowest ice content (IC), the highest unfreezable water (UFW), and the lowest frozen water (FW). Overall, this ice cream was more acceptable in terms of sensory attributes in comparison with the control sample and could be supplied to consumers as a novel, high‐quality, and marketable ice cream.