Natural apple pectin powder (HM – high methoxyl) is usually combined with sugars and acids (sometimes with the addition of fruit pastes) to form thermo-reversible gels.
Apple Pectin is a *hydrocolloid and is usually applied with sugar to aid dispersion. It is classically used as a setting agent in jam production whereas the hot sweet solution cools the molecules stop moving and bonded by the pectin chains form a network that eventually sets.
*hydrocolloid is defined as a colloid system where the colloid particles are dispersed in water. A colloid system is simply a system or mixture in which two substances are interspersed between each other. A hydrocolloid has colloid particles spread throughout water and depending on the quantity of water available can take on different states, e.g.: gel or sol (liquid).
El Bulli's Vanilla Transparent Fruit Pâté. - Ferran Adria
In spite of the total absence of fruit this pate has an unmistakeably fruit flavour. The tang of the citric acid followed by the intense sweetness and vanilla flavour cause the pallet to assume a fruit presence.
A range of different fruit pates can be obtained by utilising an assortment of fruit purees in the base. Flavour drops can then be used to enhance the chosen puree or as a second flavour note e.g. apple & blackcurrant or blueberry & lime etc.
Jam Setting Agent:
The amount of pectin required for setting a jam solution is dependent on the quantities of natural pectin already available in the selected fruit, the acidity levels (pH) & the amount of sugar. For example; in a standard recipe of equal quantities fruit to sugar, plums require the addition of approx.0.2% pectin to ensure setting where as a strawberry jam may require pectin at 0.7%. A gel network is formed when there is the correct ratio of pectin (0.5-1%), fruit solids, sugar (60-65%) and water at a pH of between: 2.5-3.5. The pH is typically adjusted\controlled by the addition of citric acid at around 0.5%.
Specific temperatures are required to complete the jam making process; a jam at 103°C will have the required 65% sugar concentration for correct setting when produced at sea level, however the relationship between the boiling point of a liquid & its altitude dictates that this temperature is 1°C lower for every 165mt elevation, so jam production temperatures should be adjusted geographically. The required acid is added near the end of cooking (to avoid breaking down the pectin) & the jam can be checked for setting either by measuring the total soluble solid percentage with a refractometer or cooling a small quantity of the jam & checking the consistency.
As the natural composition of fruit varies according to season, growing region & selected variety the following recipes are approximate guidelines for production. In all recipes, mix together the sugar & pectin, combine with the fruit, bring to the boil & heat to 103°C for 4 minutes, add the acid, check setting & pack in to jars.