Using kappa carrageenan and locust bean gum together in dairy products is a common practice because they have synergistic effects, meaning they work together to enhance the overall quality of the product more effectively than when used alone. Here's a detailed look at why they are used together and recommended usage amounts:

Why Use Kappa Carrageenan and Locust Bean Gum Together

1. Synergistic Interaction: When used together, they interact synergistically to provide a more desirable texture and consistency. This interaction often allows for the use of lower quantities of each stabilizer than would be needed if used separately.
2. Improved Texture and Viscosity: This combination often results in a smoother, creamier texture and an improved mouthfeel in dairy products.
3. Stabilization: They help maintain the stability of dairy products, preventing separation and improving shelf life.
4. Control of Ice Crystal Formation: In frozen dairy products like ice cream, this combination can help control the size of ice crystals, resulting in a creamier texture.

Recommended Amounts for Dairy Products

The exact amount to use can vary depending on the specific product and desired texture, but here are some general guidelines:

1. Ice Cream:

   • Carrageenan: 0.01% to 0.03% of the total weight.
   • Locust Bean Gum: 0.1% to 0.3% of the total weight.
   • When used together, you may slightly reduce each amount, adjusting based on trial batches to achieve the desired texture.

2. Yogurt:

   • Carrageenan: Around 0.02% to 0.05%.
   • Locust Bean Gum: Typically 0.1% to 0.5%.
   • The combined use might allow for slight reductions in these percentages.

3. Custards and Puddings:

   • Carrageenan: 0.02% to 0.1%.
   • Locust Bean Gum: 0.1% to 0.5%.
   • Adjust the ratio according to the desired firmness and creaminess.

General Guidelines

• Start Small and Adjust: Begin with the lower end of these ranges and adjust based on testing and desired texture.
• Proper Mixing: Ensure thorough dispersion and hydration of both gums in the mixture to avoid lumps and ensure uniform texture.
• Complementary Properties: Carrageenan provides a more gel-like structure, while locust bean gum contributes to creaminess and resistance to melting, especially in frozen products.

Important Considerations

• Quality and Grade: The specific type (i.e., kappa, iota, lambda carrageenan) and grade of carrageenan and locust bean gum can impact their functionality. Choose the appropriate one for your specific application.
• Regulatory Guidelines: Be aware of any food regulatory guidelines or limits in your region for the use of these gums.
• Sensory Testing: Conduct sensory testing, as overuse can lead to undesirable textures, like being too firm or gummy.

Since dairy products can vary greatly in their composition and desired textures, these recommendations should be seen as starting points. Adjustments based on trial batches are often necessary to achieve the best results.