Physicochemical and Sensory Properties of Probiotic Fermented Sheep Milk Fortified with Inulin and Sodium Butyrate

Background/Objectives: In the production of functional foods, bioactive compounds are commonly incorporated into the product, including dietary fibre, polyols, probiotics and prebiotics, unsaturated fatty acids, vitamins, minerals, and other health-promoting constituents. Such ingredients are used, among others, for the fortification of dairy products. From a technological perspective, inulin used in food production is a white powder that dissolves readily in hot water, whereas in cold water it tends to precipitate. It is characterised by a neutral odour and taste. Recent findings, in turn, indicate that sodium butyrate exhibits anti-inflammatory and immunomodulatory effects in intestinal diseases and may be applied in their treatment. The aim of this study was to evaluate the effect of the addition of inulin, as well as inulin combined with sodium butyrate, on the physicochemical characteristics and organoleptic quality of sheep milk fermented with six different probiotic monocultures. Methods: Fermented sheep milk samples supplemented with inulin or with the combination of inulin and sodium butyrate were analyzed for instrumental color parameters, pH, titratable acidity, and syneresis. Organoleptic evaluation was also performed. For each probiotic strain, three variants were prepared: a control without additives, a variant with 4% inulin, and a variant with 4% inulin and 0.06% sodium butyrate. Results: Supplementation with inulin or with the combination of inulin and sodium butyrate significantly affected instrumental color parameters. In most cases, the pH values of supplemented fermented milk samples were higher than those of the control samples. The highest pH values were observed in milk fermented by L. rhamnosus Lr32 and supplemented with inulin or with inulin and sodium butyrate. Moreover, syneresis of milk enriched with inulin as well as with inulin and sodium butyrate was significantly lower than that of the control samples, regardless of the probiotic strain applied. Conclusions: Considering the limited availability of probiotic sheep milk products on the market, the obtained results indicate that fermented sheep milk enriched with probiotic strains, inulin, and sodium butyrate may represent a promising matrix for the development of novel functional dairy products. This study also provides new insights into the application of sodium butyrate and inulin in probiotic fermented sheep milk.