Modeling and analyzing rheological behavior of sour lemon juice concentrate using image processing methods

Area of Science:

• Food Science
• Rheology
• Chemical Engineering

Background:

• Understanding the rheological properties of fruit juice concentrates is crucial for processing and storage.
• Sour lemon juice concentrate (SLJC) is a widely used food ingredient, but its physical properties require detailed investigation.

Purpose of the Study:

• To investigate the temperature-concentration dependent rheological behavior of sour lemon juice concentrate (SLJC).
• To compare the effects of atmospheric and vacuum processing methods on SLJC rheology and quality parameters.

Main Methods:

• Rheological properties of SLJC were measured using a rheometer across various temperatures (10-50°C) and concentrations (31-51°Bx).
• SLJC samples were produced under both atmospheric and vacuum conditions.
• Temperature-viscosity data were modeled using surface equations and visualized through image analysis.
• Ascorbic acid and HMF content were analyzed.

Main Results:

• SLJC demonstrated Newtonian flow behavior across the tested conditions.
• Vacuum-processed SLJC exhibited significantly higher viscosity (p < .05) than atmospherically processed SLJC.
• Activation energy values were lower for vacuum-processed SLJC (9.0-17.9 kJ/mol) compared to atmospheric (13.6-24.0 kJ/mol).
• Viscosity increased with concentration and decreased with temperature.
• Vacuum processing resulted in higher ascorbic acid and lower HMF content.

Conclusions:

• The rheological behavior of SLJC is predictable and can be modeled effectively.
• Vacuum processing is a superior method for producing SLJC, enhancing viscosity and preserving quality attributes like ascorbic acid while minimizing degradation products like HMF.