Industrial scale microwave processing of tomato juice using a novel continuous microwave system

Area of Science:

• Food Science and Technology
• Biotechnology
• Chemical Engineering

Background:

• Conventional pasteurization is standard for ensuring microbial safety in tomato juice.
• Evaluating novel processing technologies is crucial for improving food quality and functionality.
• Microwave heating offers potential for rapid and efficient food processing.

Purpose of the Study:

• To compare a continuous flow microwave volumetric heating system with conventional pasteurization for tomato juice.
• To assess the impact of both methods on physicochemical properties, microbial load, and antioxidant capacity.
• To investigate the cytoprotective effects of processed tomato juice against oxidative stress.

Main Methods:

• Industrial scale continuous flow microwave volumetric heating system.
• Conventional commercial scale pasteurization.
• Analysis of physicochemical properties, color, microbial counts, and antioxidant capacity (ABTS, ORAC).
• In vitro digestion and assessment of cytoprotective effects against H2O2-induced oxidation in Caco-2 cells.
• Organoleptic analysis.

Main Results:

• Physicochemical properties and color remained similar between microwave and conventional pasteurization, and during storage.
• Both methods effectively inactivated microorganisms, maintaining low levels throughout storage.
• Microwave pasteurized juice showed higher initial antioxidant capacity (ABTS) and enhanced cytoprotective effects against oxidative stress.
• Organoleptic analysis indicated no significant differences in taste and quality between the two processed juices.

Conclusions:

• Continuous microwave volumetric heating is a viable alternative to conventional pasteurization for tomato juice.
• Microwave processing maintains key quality attributes and microbial safety.
• This technology offers potential for enhanced functional properties, such as antioxidant capacity and cytoprotection.