FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Effect of selected freezing technologies on count of Lactobacillus casei ŁOCK 0900, antioxidant activity and sensory characteristics of fermented pumpkin-based sorbets


The objective of the research study was to determine the effect of some selected freezing technologies on the survival of the Lactobacillus rhamnosus ŁOCK 0900 probiotic bacterial strain, on the sensory quality and antioxidant activity of sorbets made from pumpkin flesh. The scope of study included: the production of three types of sorbets under the laboratory conditions, where the following was applied: (1) classical freezing, (2) dry ice and (3) liquid nitrogen; the determination of the count of probiotic Lactobacillus rhamnosus ŁOCK 0900 bacteria strain in the product; the measurement of the pH value and the assessment of changes in the sensory quality of the products during their storage at -18 ºC for 16 weeks. In addition, the antioxidant activity of the raw material and fresh, finished products was determined. It was found that, irrespective of the sorbets production technology used, the count of LAB bacteria decreased in the products (by ca. 1 logarithmic row) with the storage time passing, however when the liquid nitrogen and dry ice technology were used to freeze the products, more bacterial cells survived compared to the classical method used. Also, the type of the technology applied to manufacture the sorbets determined the sensory quality of those desserts. The highest scores received the overall sensory quality of the products manufactured using the liquid nitrogen technology. Compared to the initial raw material, the  finished products showed a significantly higher value of antioxidant activity and this increase was caused by the
fermentation process.


pumpkin, sorbets manufacturing technologies, probiotics, sensory quality, antioxidant activity