《食品加工原理》课程PPT教学课件（福建农林大学）Chapter 3 PASTEURIZATION AND BLANCHING

PASTEURIZATION AND BLANCHING • PURPOSE OF THE PROCESSES • DESCRIPTION OF PROCESSING SYSTEMS • ESTABLISHMENT OF THE PASTEURIZATION PROCESS • DETERMINATION OF BLANCHING PROCESS • PROCESSES FOR PRODUCT QUALITY IMPROVEMENT • SUMMARY

PASTEURIZATION AND BLANCHING • PURPOSE OF THE PROCESSES • DESCRIPTION OF PROCESSING SYSTEMS • ESTABLISHMENT OF THE PASTEURIZATION PROCESS • DETERMINATION OF BLANCHING PROCESS • PROCESSES FOR PRODUCT QUALITY IMPROVEMENT • SUMMARY

Vocabulary • pasteurization blanching • mild \severe \batch-type \continuous • brucellosis tuberculosis Salmonella Listeria • enzyme inactivation • plate heat exchanger\ \a flow diversion valve (FDV) \cooling medium\ \high temp.- short-time (HTST) \ \ultra-high-temperature (UHT) \\conveyor tunnel

Vocabulary • pasteurization blanching • mild \severe \batch-type \continuous • brucellosis tuberculosis Salmonella Listeria • enzyme inactivation • plate heat exchanger\ \a flow diversion valve (FDV) \cooling medium\ \high temp.- short-time (HTST) \ \ultra-high-temperature (UHT) \\conveyor tunnel

• The processes that utilize relatively mild thermal treatments to achieve the desired results are pasteurization and blanching. Both processes apply thermal treatment to food products in an effort to improve the stability of the product during storage

• The processes that utilize relatively mild thermal treatments to achieve the desired results are pasteurization and blanching. Both processes apply thermal treatment to food products in an effort to improve the stability of the product during storage

• Although the magnitude of the thermal processes is similar, application of the processes involves two distinctly different types of food products. Pasteurization is most often associated with liquid foods, while blanching is most often associated with solid foods

• Although the magnitude of the thermal processes is similar, application of the processes involves two distinctly different types of food products. Pasteurization is most often associated with liquid foods, while blanching is most often associated with solid foods

• The magnitude of thermal treatment used for both processes is not sufficient to establish storage stability at room temperature. The criteria utilized in establishing these modest thermal treatments are rather specific and are different for different food commodities

• The magnitude of thermal treatment used for both processes is not sufficient to establish storage stability at room temperature. The criteria utilized in establishing these modest thermal treatments are rather specific and are different for different food commodities

Purpose of Pasteurization Processing • Pasteurization is a mild thermal process applied to a liquid food to increase the product shelf life during refrigeration and to destroy vegetative pathogens (brucellosis and tuberculosis), Salmonella and Listeria. • In fruit juice ,to inactivate enzymes

Purpose of Pasteurization Processing • Pasteurization is a mild thermal process applied to a liquid food to increase the product shelf life during refrigeration and to destroy vegetative pathogens (brucellosis and tuberculosis), Salmonella and Listeria. • In fruit juice ,to inactivate enzymes

Purpose of Blanching Processing • In fruits and vegetables to inactivate enzymes. • To removes air from intercellular spaces of a fruit or vegetable • Before canning raw fruits and vegetables and the more severe thermal processes associated with commercial sterilization

Purpose of Blanching Processing • In fruits and vegetables to inactivate enzymes. • To removes air from intercellular spaces of a fruit or vegetable • Before canning raw fruits and vegetables and the more severe thermal processes associated with commercial sterilization

DESCRIPTION OF PROCESSING SYSTEMS • batch-type operation pasteurization • continuous high temperature, short-time (HTST) pasteurization system • rotary hot water system blanching system • Steam blanchers

DESCRIPTION OF PROCESSING SYSTEMS • batch-type operation pasteurization • continuous high temperature, short-time (HTST) pasteurization system • rotary hot water system blanching system • Steam blanchers

Batch Pasteurization System

Batch Pasteurization System

Batch-type operation • The vessel containing the product has a jacket where a heating medium is introduced. • The liquid product in the vessel is mixed to ensure uniform temperature rise until the desired temperature is reached. • The same jacket is utilized during cooling of the product by introducing a cold medium and cooling the product contact surface

Batch-type operation • The vessel containing the product has a jacket where a heating medium is introduced. • The liquid product in the vessel is mixed to ensure uniform temperature rise until the desired temperature is reached. • The same jacket is utilized during cooling of the product by introducing a cold medium and cooling the product contact surface