In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin.

In the present study we describe a high-performance liquid chromatographic method for the simultaneous determination of α-, β-, γ- and δ-tocopherol, cis and trans isomers of retinol, and total carotenes in different Italian cheeses. The method involves sample extraction and saponification followed by normal-phase high-performance liquid chromatography (HPLC). Monitoring of the absorbance and fluorescence is achieved using a programmable spectrophotometer and a programmable spectrofluorometer connected in series. The proposed method, which has the advantage of being able to evaluate simultaneously the fat-soluble vitamins considered by us in this work, has been applied to some Italian cheeses (Percorino romano, Taleggio, Provolone, and Caciotta) and milk samples (cows', goats', and sheep milk). The HPLC analytical procedure provides excellent reproducibility of results and is less subject to interferences from the sample matrix than wet chemical techniques. These factors combine to make the simultaneous determination of α-, β-, γ-, and δ-tocopherol, cis and trans isomers of retinol, and total carotenes by HPLC a practical technique for routine quality control and chemical and nutritional research applications.