Comparison of the Effects of High Hydrostatic Pressure and Pasteurization on Quality of Milk during Storage

High hydrostatic pressure (HHP, 600 MPa/15 min), pasteurization (72 degrees C/15 s) and pasteurization-HHP (72 degrees C/15 s + 600 MPa/15 min) processing of milk were comparatively evaluated by examining their effects on microorganisms and quality during 30 days of storage at 4 degrees C. The counts of total aerobic bacteria in HHP-treated milk were less than 2.22 IgCFU/mL during storage, while they exceeded 5.00 1gCFU/mL in other treated milk. Although HHP changed the color, it had more advantages in maintaining the nutrient (fat, calcium and beta-lactoglobulin) properties of milk during storage. Moreover, the viscosity and particle size of HHP-treated milk were more similar to the untreated milk during storage. However, consumer habits towards heat-treated milk have led to poor acceptance of HHP-treated milk, resulting in a low sensory score. In sum, compared with pasteurization- and pasteurization-HHP-treated milk, HHP-treated milk showed longer shelf life and better nutritional quality, but lower sensory acceptance.

Automated summary

This study compared the effects of high hydrostatic pressure (HHP), pasteurization, and pasteurization-HHP on microorganisms and quality of milk. The results showed that HHP-treated milk had advantages in maintaining nutritional quality and shelf life, but had lower sensory acceptance.