Pectin and Locust Bean Gum (LBG) are often used together in jams and jellies to achieve a desirable texture and consistency. Here's why they are used in tandem and some guidelines on how much to use of each:

Why Use Pectin and Locust Bean Gum Together:

1. Pectin is a natural gelling agent found in many fruits. It forms a gel by interacting with sugar and acid, which is essential in jam and jelly making. Pectin provides the initial set and firmness.

2. Locust Bean Gum, a thickener derived from the seeds of the carob tree, enhances the texture of jams and jellies. It improves the mouthfeel, making it smoother. It also helps to stabilize the gel formed by pectin, preventing syneresis (the weeping of liquid from the gel).

3. Synergy: When used together, pectin provides the gel structure, while LBG enhances the texture and reduces the syneresis. This combination is particularly beneficial in low-sugar or reduced-sugar jams and jellies, where achieving a good set can be more challenging.

Recommended Proportions:

The ideal proportion of pectin and LBG can vary depending on the type of fruit, desired texture, and sugar content. However, here are some general guidelines:

• Pectin: 0.5% to 1.5% of the total weight. For example, in a recipe with 1000g of fruit and sugar combined, you would use 5g to 15g of pectin.

• Locust Bean Gum: 0.1% to 0.3% of the total weight. Using the same 1000g example, this would be 1g to 3g of LBG.

Important Considerations:

1. Fruit Type: The natural pectin content in the fruit should be considered. High-pectin fruits may require less added pectin.

2. Sugar Content: The gel strength of pectin is influenced by the amount of sugar in the recipe. Low-sugar recipes might need more pectin or the use of a special low-sugar pectin.

3. Acidity: The pH of the jam or jelly impacts pectin's gelling ability. Sometimes, acid in the form of lemon juice or citric acid may need to be added.

4. Dissolution: Ensure that both pectin and LBG are well dissolved. LBG tends to clump, so it might need to be pre-mixed with sugar before adding to the fruit mixture.

5. Cooking Process: The gelling action of pectin is activated by heat, so the cooking process is crucial. Overcooking can break down pectin and result in a runny jam.

6. Experimentation: Start with these guidelines and adjust according to your recipe and the results. The exact amount needed can vary based on the specific type of pectin and LBG used, as well as other ingredients in your formula.

Using pectin and LBG together allows for more control over the final texture of jams and jellies, especially in recipes with varying sugar contents or fruit types. It's always a good idea to do small batch tests to fine-tune the recipe to your liking.