Abstract #75

# 75
Hydrodynamic cavitation as a tool to improve texture, mouthfeel, and creaminess in formulated and high-protein, low-fat Greek yogurts.
Gopinathan H. Meletharayil*1, Hasmukh A. Patel1, 1South Dakota State University, Brookings, SD.

Greek yogurt (GY) manufacturing involves a straining step that generates acid whey, which has led to processing and environmental concerns. Non-strained yogurt (GSY) can be the solution to this problem. However, GSY is unacceptable to consumers because of its tart astringent taste, gritty and chalky texture and lack of creamy mouthfeel, taste, and flavor. We explored the use of hydrodynamic cavitation in conjunction with CO2 treated functional milk proteins to develop a low fat GSY having rheological and organoleptic profiles similar to GY. CO2 treated milk retentate was added to skim milk and NFDM base to yield 9% (w/w) protein and 17% (w/w) total solids. The mixture was heated to 90°C for 10 min followed by cooling to 42°C. The milk was fermented with yogurt culture to pH 4.6, followed by rapid cooling to less than 10°C. The yogurt was then subjected to hydrodynamic cavitation using an APV cavitator (SPX Flow Technology, Denmark). Rheology, large deformation studies, % lactic acid (LA) organic acid profiles using HPLC, graininess using microscopy and organoleptic profile (mouthfeel and creaminess) using sensory panel were investigated. Experimental data were tested for ANOVA and statistical significance (P < 0.05) was determined, using statistical software SAS. Hydrodynamic cavitation reduced the consistency coefficient of GSY to values similar to those obtained in commercial GY. Cavitation of GSY reduced the number of grains from 2389 to 35 grains/g compared with 293 grains/g in commercial GY. There was no significant difference in the LA content between the cavitated GSY and commercial GY. Organic acid profiles of the strained and non-strained cavitated yogurts were superimposable. GSY subjected to hydrodynamic cavitation had better mouthfeel and creaminess compared with commercial GY. Based on these results, it can be concluded that the combination of CO2 treated proteins and hydrodynamic cavitation can be used as a promising solution to manufacture GSY with rheological and organoleptic profiles better or similar to GY. This processing innovation will help to reduce processing times, capital investments and more importantly the vexing problem of acid whey disposal.

Key Words: hydrodynamic cavitation, Greek yogurt, texture