Characterization of ice recrystallization in ice cream during storage using the focused beam reflectance measurement

Ice recrystallization was investigated in two commercial and differently stabilized ice creams using an original and real time particles counting and sizing method: the focused beam reflectance measurement (FBRM). Ice cream A (with locust bean gum - LBG - as primary stabilizer) and ice cream B (with carrageenan as primary stabilizer) were stored for 154 days at four different temperatures (-5, -8, -12 and -18°C) and three amplitudes of temperature fluctuations (±0.1°C, ±0.75°C, ±2.5°C). Crystal's size distributions were assessed at various time and recrystallization kinetic data were derived by fitting the experimental results to the asymptotic Ostwald ripening model. As expected, recrystallization rates increase with mean storage temperature and amplitude of temperatures fluctuations. Carrageenan seems to be more effective than LBG in slowing down ice crystal growth during storage. Mean ice crystal size increased as a function of time1/3 for both ice creams. The temperature dependence of recrystallization rate fitted Arrhenius well, with activation energies fairly similar for ice creams A and B.