Lipid oxidation volatiles absent in milk after selected ultrasound processing.

Ultrasonic processing can suit a number of potential applications in the dairy industry. However, the impact of ultrasound treatment on milk stability during storage has not been fully explored under wider ranges of frequencies, specific energies and temperature applications. The effect of ultrasonication on lipid oxidation was investigated in various types of milk. Four batches of raw milk (up to 2L) were sonicated at various frequencies (20, 400, 1000, 1600 and 2000kHz), using different temperatures (4, 20, 45 and 63°C), sonication times and ultrasound energy inputs up to 409kJ/kg. Pasteurized skim milk was also sonicated at low and high frequency for comparison. In selected experiments, non-sonicated and sonicated samples were stored at 4°C and were drawn periodically up to 14days for SPME-GCMS analysis. The cavitational yield, characterized in all systems in water, was highest between 400kHz and 1000kHz. Volatile compounds from milk lipid oxidation were detected and exceeded their odor threshold values at 400kHz and 1000kHz at specific energies greater than 271kJ/kg in raw milk. However, no oxidative volatile compounds were detected below 230kJ/kg in batch systems at the tested frequencies under refrigerated conditions. Skim milk showed a lower energy threshold for oxidative volatile formation. The same oxidative volatiles were detected after various passes of milk through a 0.3L flow cell enclosing a 20kHz horn and operating above 90kJ/kg. This study showed that lipid oxidation in milk can be controlled by decreasing the sonication time and the temperature in the system depending on the fat content in the sample among other factors.

[1]  J. Graves,et al.  New evidence for the inverse dependence of mechanical and chemical effects on the frequency of ultrasound. , 2011, Ultrasonics sonochemistry.

[2]  Muthupandian Ashokkumar,et al.  Ultrasonic processing of dairy systems in large scale reactors. , 2010, Ultrasonics sonochemistry.

[3]  Hongyu Wu,et al.  Effects of ultrasound on milk homogenization and fermentation with yogurt starter. , 2000 .

[4]  V. Crow,et al.  Ester synthesis in an aqueous environment by Streptococcus thermophilus and other dairy lactic acid bacteria , 2003, Applied Microbiology and Biotechnology.

[5]  Jayani Chandrapala,et al.  Ultrasonics in food processing. , 2012, Ultrasonics sonochemistry.

[6]  S Martini,et al.  Altering functional properties of fats using power ultrasound. , 2010, Journal of food science.

[7]  Da-Wen Sun,et al.  Innovative applications of power ultrasound during food freezing processes—a review , 2006 .

[8]  G. Norris,et al.  Characterisation of esterases of Streptococcus thermophilus ST1 and Lactococcus lactis subsp. cremoris B1079 as alcohol acyltransferases , 2004 .

[9]  Moholkar,et al.  Modeling of the acoustic pressure fields and the distribution of the cavitation phenomena in a dual frequency sonic processor , 2000, Ultrasonics.

[10]  P. Juliano,et al.  Enhanced creaming of milk fat globules in milk emulsions by the application of ultrasound and detection by means of optical methods. , 2011, Ultrasonics sonochemistry.

[11]  M. Ashokkumar,et al.  Minimising oil droplet size using ultrasonic emulsification. , 2009, Ultrasonics sonochemistry.

[12]  A. Pandit,et al.  Sonocrystallization: effect on lactose recovery and crystal habit. , 2007, Ultrasonics sonochemistry.

[13]  Inez Hua,et al.  Impact of Ultrasonic Frequency on Aqueous Sonoluminescence and Sonochemistry , 2001 .

[14]  P. Gogate,et al.  Effect of dissolved gas on efficacy of sonochemical reactors for microbial cell disruption: Experimental and numerical analysis. , 2009, Ultrasonics sonochemistry.

[15]  W. Grosch,et al.  Evaluation of taste compounds of Swiss cheese (Emmentaler) , 1996 .

[16]  Carmen Rosselló,et al.  Effect of Acoustic Brining on Lipolysis and on Sensory Characteristics of Mahon Cheese , 2001 .

[17]  H. Siebert,et al.  Schwellenkonzentrationen von Aromastoffen und ihre Nutzung zur Auswertung von Aromaanalysen , 1972 .

[18]  K. Knoerzer,et al.  A computational modeling approach of the jet-like acoustic streaming and heat generation induced by low frequency high power ultrasonic horn reactors. , 2011, Ultrasonics sonochemistry.

[19]  A. Henglein,et al.  Sonochemistry and sonoluminescence: effects of external pressure , 1993 .

[20]  Yves Lion,et al.  Sonolysis of aqueous surfactant solutions. Probing the interfacial region of cavitation bubbles by spin trapping , 1989 .

[21]  P. Schieberle,et al.  Evaluation of key aroma compounds in hand-squeezed grapefruit juice (Citrus paradisi Macfayden) by quantitation and flavor reconstitution experiments. , 2001, Journal of agricultural and food chemistry.

[22]  R. Buttery,et al.  Volatile aroma components of cooked artichoke , 1978 .

[23]  James G. Lyng,et al.  Characterisation of volatile compounds generated in milk by high intensity ultrasound , 2009 .

[24]  Silvana Martini,et al.  Effect of High Intensity Ultrasound on Crystallization Behavior of Anhydrous Milk Fat , 2008 .

[25]  James G. Lyng,et al.  The effect of thermosonication of milk on selected physicochemical and microstructural properties of yoghurt gels during fermentation , 2009 .

[26]  P. López-Buesa,et al.  Rheological properties of yoghurt made with milk submitted to manothermosonication. , 2002, Journal of agricultural and food chemistry.

[27]  M. Ashokkumar,et al.  The application of ultrasound to dairy ultrafiltration : the influence of operating conditions , 2007 .

[28]  Piotr Swiergon,et al.  Creaming enhancement in a liter scale ultrasonic reactor at selected transducer configurations and frequencies. , 2013, Ultrasonics sonochemistry.

[29]  Stefania Balzan,et al.  Effect of ultrasound alone or ultrasound coupled with CO2 on the chemical composition, cheese-making properties and sensory traits of raw milk , 2012 .

[30]  Shaoquan Liu,et al.  Esters and their biosynthesis in fermented dairy products: a review , 2004 .

[31]  Pablo Juliano,et al.  Impact of ultrasound treatment on lipid oxidation of Cheddar cheese whey. , 2014, Ultrasonics sonochemistry.

[32]  Muthupandian Ashokkumar,et al.  Sonoluminescence, sonochemistry (H2O2 yield) and bubble dynamics: frequency and power effects. , 2008, Ultrasonics sonochemistry.

[33]  Magdi M. Mossoba,et al.  Chemical effects of ultrasound on aqueous solutions. Formation of hydroxyl radicals and hydrogen atoms , 1983 .

[34]  P. Juliano,et al.  Design parameters for the separation of fat from natural whole milk in an ultrasonic litre-scale vessel. , 2014, Ultrasonics sonochemistry.

[35]  Timothy G. Leighton,et al.  Bubble population phenomena in acoustic cavitation , 1995 .

[36]  S. Karlović,et al.  Influence of high intensity ultrasound with different probe diameter on the degree of homogenization (variance) and physical properties of cow milk , 2011 .

[37]  Muthupandian Ashokkumar,et al.  Modification of food ingredients by ultrasound to improve functionality: A preliminary study on a model system , 2008 .

[38]  D. Kirpalani,et al.  Experimental quantification of cavitation yield revisited: focus on high frequency ultrasound reactors. , 2006, Ultrasonics sonochemistry.

[39]  J. Chandrapala,et al.  Application of ultrasound to reduce viscosity and control the rate of age thickening of concentrated skim milk , 2013 .

[40]  T. Richardson,et al.  Antioxidant activity of skim milk: effect of sonication. , 1980, Journal of dairy science.

[41]  R. Buttery,et al.  Contribution of volatiles to rice aroma , 1988 .

[42]  N. P. Vichare,et al.  Cavitation reactors: Efficiency assessment using a model reaction , 2001 .

[43]  M. Ashokkumar,et al.  The effect of surface active solutes on bubbles in an acoustic field. , 2007, Physical chemistry chemical physics : PCCP.

[44]  Muthupandian Ashokkumar,et al.  The ultrasonic processing of dairy products — An overview , 2010 .

[45]  Alex Patist,et al.  Ultrasonic innovations in the food industry: From the laboratory to commercial production , 2008 .

[46]  M. Kontominas,et al.  Effect of ultrasonication on microbiological, chemical and sensory properties of raw, thermized and pasteurized milk , 2010 .

[47]  P. Schieberle,et al.  Evaluation of the character impact odorants in fresh strawberry juice by quantitative measurements and sensory studies on model mixtures , 1997 .

[48]  P. Schieberle,et al.  Evaluation of aroma differences between hand-squeezed juices from Valencia late and Navel oranges by quantitation of key odorants and flavor reconstitution experiments. , 2001, Journal of agricultural and food chemistry.

[49]  James G. Lyng,et al.  A comparison of selected quality characteristics of yoghurts prepared from thermosonicated and conventionally heated milks , 2010 .

[50]  Xiao Dong Chen,et al.  A Laboratory Investigation of Milk Fouling Under the Influence of Ultrasound , 2007 .

[51]  T. J. Siek,et al.  Comparison of Flavor Thresholds of Aliphatic Lactones with Those of Fatty Acids, Esters, Aldehydes, Alcohols, and Ketones, , 1971 .

[52]  Aniruddha B. Pandit,et al.  Sonochemical reactors: important design and scale up considerations with a special emphasis on heterogeneous systems , 2011 .