Effect of Butternut Squash (Cucurbita moschata) Seed Powder on the Chemical and Rheological Properties of Stirred Cultured Camel Milk and Yoghurt

Research shows that producing fermented camel milk is hard because of the milk’s inability to form a firm coagulum, attributed to low levels of κ-casein and ꞵ-lactoglobulin and the large casein micelle size, leading to a weak network of casein formation. In an effort to address this issue, researchers turned to corn starch as a thickening agent, discovering that a concentration of 2.0% effectively improved the viscosity and significantly reduced syneresis in stirred camel milk yoghurt and cultured camel milk. This study explores alternatives to corn starch, focusing on butternut squash seeds as a promising substitute due to their hydrocolloid composition. By incorporating butternut squash (Cucurbita moschata) seed powder (BSSP) as a thickening agent, this study aimed at enhancing the chemical and rheological properties of stirred camel milk yoghurt and cultured camel milk. Fermented camel milk was prepared using 4 litres of camel milk, 2% starter cultures (thermophilic culture for yoghurt and mesophilic aromatic culture for stirred cultured camel milk) and BSSP 0.0% (negative control), 0.4%, 0.8%, 1.2%, 1.6%, 2.0% mixed with 0.4% gelatin. 2.0% corn starch mixed with 0.4% gelatin was used as a standard for comparison. Results showed that increasing the BSSP level significantly (p < 0.05) decreased the moisture content while increasing the total solid content of stirred fermented camel milk products. There was an increase in ash content with an increase in BSSP levels. There was a significant (p < 0.05) reduction in the pH, with an increase in BSSP levels in stirred fermented camel milk samples. Increasing the concentration of BSSP from 0.4% to 2.0% resulted in a significant (p < 0.05) increase in viscosity and a reduction in syneresis of stirred camel milk yoghurt and stirred cultured camel milk samples. This study demonstrated that BSSP effectively enhances the viscosity, reduces syneresis and increases acidity in stirred fermented camel milk products during storage.

Buffalo stirred yoghurt fortified with grape seed extract:New insights into its functional properties

Grape seed extract(GSE)is considered one of the major byproducts,which are rich in phenolic content and possess several health-promoting activities including antibacterial,anticancer,and antioxidant.The current research was devoted to improve the bioactive properties of stirred yoghurt through supplementation with GSE at three concentrations(0.1,0.25,and 0.5 g/100 g yoghurt).The obtained stirred yoghurts were analyzed for determining their composition,pH,syneresis,viscosity,and sensory evaluation.Furthermore,some functional properties including antioxidant,antibacterial,anticancer activities were estimated.Significant increments(p≤0.05)were observed in total solids,ash contents,pH,water holding capacity,and viscosity values,especially when 0.5%GSE was added.Moreover,adding 0.5%GSE showed higher(p≤0.05)in vitro antioxidant,antibacterial,and anticancer activities.Interestingly,the improved bioactive properties resulting from adding GSE,even at the higher concentration,were not accompanied by any change in sensory properties.In particular,the color descriptor was mostly preferred by panelists when 0.5%GSE was added.The assessors did not observe any off-flavors in any of the tested stirred yoghurt samples.Therefore,the functional properties of stirred yoghurt could be improved by adding GSE preparation without affecting its organoleptic properties.