Development of Vacuum-Steam Combination Heating System for Pasteurization of Sprout Barley Powder

Area of Science:

• Food Science
• Microbiology
• Process Engineering

Background:

• Sprout powders offer extended shelf-life and retained nutrients but are susceptible to microbial contamination.
• Effective decontamination methods are crucial for sprout powder safety without compromising quality.

Purpose of the Study:

• To identify an optimal pasteurization technique for sprout barley powder.
• To assess the impact of a combined vacuum-steam heating treatment on microbial inactivation and quality attributes of sprout barley powder.

Main Methods:

• A vacuum-thermal combination system with a far-infrared heater and PID controller was developed for heating sprout barley powder.
• Discrete element modeling (EDEM™) was used to optimize stirring blade design for uniform powder mixing.
• Microbial inactivation (E. coli O157:H7), CIE color values, and water activity (a_w) were measured to evaluate quality changes.

Main Results:

• The vacuum-steam treatment significantly reduced E. coli O157:H7 populations by 4.33 log CFU/g, achieving complete elimination.
• Steam injection at regular intervals facilitated heat and moisture transfer during the two-hour pasteurization process.
• The vacuum environment effectively decreased water activity without causing significant quality deterioration.

Conclusions:

• Combined vacuum-steam heating is a viable and effective pasteurization method for sprout barley powder.
• This method ensures microbial safety while maintaining the quality attributes of sprout barley powder.
• The developed system offers a promising approach for producing safe and high-quality sprout powders.