Textural and Rheological Properties of Sliceable Ketchup

Area of Science:

• Food Science
• Rheology
• Material Science

Background:

• Ketchup's texture and stability are influenced by hydrocolloids.
• Optimizing gum mixtures is key for desirable ketchup properties.

Purpose of the Study:

• To investigate the impact of various gum mixtures (xanthan, konjac mannan, gellan, locust bean gum) on ketchup's physical, rheological, and textural characteristics.
• To determine the optimal gum combinations for sliceable ketchup.

Main Methods:

• Formulation of ketchup with different gum mixtures.
• Analysis of physical properties (syneresis, color).
• Rheological testing (steady-state and unsteady-state), textural analysis, particle size distribution, and scanning electron microscopy.

Main Results:

• Xanthan gum (Xa) mixtures significantly increased viscosity and reduced syneresis, with a 50% Xa/50% gellan blend showing the lowest syneresis.
• Gum ratios significantly affected the yellowness index but not brightness or redness.
• Firmness was significantly influenced by gum levels, while other textural parameters were not.
• Ketchup exhibited shear-thinning behavior, best described by the Carreau model.
• All samples displayed weak gel structures with G' > G'' and monodispersed particle distribution.

Conclusions:

• Gum mixtures, particularly those including xanthan gum, are crucial for controlling ketchup's rheological and textural properties.
• Optimized gum blends can enhance ketchup's stability, texture, and sliceability.
• The study provides insights into hydrocolloid functionality for food product development.