Thermal processing of cocoa liquor using a scraped-surface heat exchanger

Overview

This advanced thermal processing technology uses a scraped-surface heat exchanger (SSHE) to pasteurize cocoa liquor, providing an effective solution for microbial reduction while maintaining the product's sensory and functional attributes. The system is tailored for high-viscosity, high-fat matrices, ensuring uniform heat transfer and preventing localized overheating and flavor degradation. By rapidly heating the cocoa liquor to a target temperature and maintaining it for a validated residence time, the SSHE system effectively achieves a 2-log reduction in Total Viable Count (TVC) without compromising the liquor's aroma, flavor, and rheology.

Technical specifications

• Continuous, closed-system design: Ensures efficient pasteurization with minimal contamination risk.
• Scraped-surface mechanism: Rotating scrapers continuously renew the product film at the heat-transfer surface, enhancing heat transfer and preventing burn-on.
• High-temperature/short-time processing: Maintains product quality by minimizing exposure to heat while ensuring microbial safety.
• Adaptability: Engineered for high-viscosity, high-fat matrices common in cocoa liquor, enabling effective processing where conventional methods fail.
• Pilot system capacity: Capable of processing 120 gallons per hour, with plans for scale-up.

Technology readiness level

This technology is at TRL 6, having been validated in a relevant environment with plans for further optimization and scale-up. The process has been tested under worst-case conditions, demonstrating consistent microbial reduction and product quality retention.