Research
Thermosonication in dairy systems (Graduate)
Thermosonication is the application of soundwaves at temperatures ≥50 °C. It can be used to improve functional properties, overall quality, and shelf life of dairy products. Milk is concentrated before being spray dried and currently milk concentration is limited by increased viscosity. Decreasing the viscosity of concentrates prior to spray drying could be economically beneficial to dairy processors. Results from this study showed that that thermosonication significantly reduced the viscosity of concentrates such as reconstituted milk protein concentrate (rMPC) and reconstituted skim milk powder (rSMP). This would allow for spray drying of these concentrates at a higher total solids with a lower viscosity.
Currently, the shelf of pasteurized fluid milk stored at refrigeration temperatures is 2-3 weeks and is limited due to bacterial growth during refrigerated storage. Increasing milk shelf life would potentially minimize product loss and consumers can enjoy their refrigerated milk for longer time. Some thermophilic bacterial cells and spores can survive high temperatures involved in dairy processes and decrease milk product quality. Minimizing losses due to product quality loss could potentially minimize losses for dairy producers and It would be beneficial to improve dairy product shelf life and quality by eliminating these microorganisms using thermosonication.
The effect of thermosonication at pasteurization temperatures on survival of total and thermophilic bacteria such as Geobacillus stearothermophilus, Anoxybacillus flavithermus, and Bacillus subtilis in both batch and continuous systems was studied. Results showed that thermosonication successfully reduced thermophilic bacterial cells but not spores. Moreover, the cell reductions observed may not have an impact on milk product quality. Thermosonication along with pasteurization successfully improved the milk microbial quality along with other quality indicators such as pH and free fatty acid (FFA) content. Milk shelf life was extended by 2 weeks and minimal changes in consumer acceptance of milk were observed. Thus, thermosonication along with pasteurization could be used to improve milk quality and shelf life and decrease the viscosity of milk concentrates.
A big part of my research was to design shelf life studies and conducting sensory panels using thermosonication samples. Designing experiments along with accurate statistical analysis was also implemented. Shelf life study involved learning plating techniques from microbiology, but also analytical tests such as free fatty acid analysis, casein extraction, sulfur group analysis. While working with Dr. Marie Walsh as my advisor, I had the opportunity to be a teaching assistant to her graduate level classes for proteins and enzymes and dairy chemistry. Dr. Walsh has been a great mentor and has guided and helped me throughout my research to mitigate any road blocks.
Green Approaches to Cleaning (Undergraduate)
As an undergraduate student I was given the opportunity to work on a research project that used eco-friendly cleaning methods and was specifically targetted towards the wine industry wastes. The purpose of the project was to develop environmentally friendly methods for cleaning and sanitizing process in the food and wine industries through the use of alternative cleaning chemicals and low chemical cleaning methods.
The cleaning methods developed included a high pressure cleaning system that eliminated the use of a detergent, cleaning with eco-friendly chemicals, and use of filtration to reuse the cleaning water obtained from the implemented cleaning systems. I was more involved in developing the filtration system in this project. Through this research, I gained hands on experience in chemical testing of wine waste and data analysis, which got me interested in graduate school.
Peer Reviewed Publications
•Deshpande, V.K, Walsh, M.K. (2018). Effect of sonication on the viscosity of reconstituted skim milk powder and milk protein concentrate as influenced by solids concentration and temperature. International Dairy Journal.,78, 122-129.
•Deshpande, V. K., Walsh, M. K. (2020). Effect of thermosonication in a batch system on the survival of spore-forming bacteria. International Journal of Dairy Technology.