investigation into grounding of mv berlin express：在mv柏林快递接地的调查.pdf

Journal of Hygienic Engineering and Design 26 Original scientific paper UDC :]: INFLUENCE OF THERMO-SONICATION ON MICROBIOLOGICAL SAFETY, COLOR AND ANTHOCYANINS CONTENT OF STRAWBERRY JUICE Zoran Herceg 1*, Vesna Lelas 1, Anet Re?ek Jambrak 1, Tomislava Vuku?i? 1, Branka Levaj 1 1Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia *e-mail: ******@ Abstract Ultrasonication is an alternative method of food preser - vation that has the advantage of inactivating microor - ganisms in food without causing mon side-ef - fects associated with conventional heat treatments, such as nutrient, color and flavor loss. In this work high intensity ultrasound was used to investigate inactiva - tion anisms, preservation the anthocyanins content and consequently color stability of strawberry juices. Juice samples, cloudy (sample A) and clear (B) juices, were treated with ultrasonic probe of 12 mm in di - ameter and with 20 kHz frequencies. For ultrasounds treatment, three parameters (amplitude, treatment time and temperature of sample) varied according to the statistical experimental design. posite design was used to optimize and design experimental parameters: temperature (25, 40 and 55 0C), amplitude (60, 90 and 120 μm) and time (3, 6, and 9 minutes). Thermal pasteurization (85 0C/2 min) reduces total anthocyanin content for to % but inactivate all pared to untreated juices. After treatment with ultrasound (20 0C for 3, 6 or 9 min.) or thermo-sonication (40 0C for 3, 6 or 9 min. and 55 0C for 3 or 6 min.), the degradation of anthocyanins was gen - erally less intensive and was to % and inactivate from 58 to 94% of pared to the untreated juices. Only in the case of ultrasonic treat - ment at a temperature of 55 0C and treatment time of 9 min. the total content of anthocyanins, compared to untreated juice, was reduced by to %, and their degradation was gr