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Generally speaking, there are three broad ranges of pectins: 1) High Methoxyl (HM), 2) Low Methoxyl Conventional (LMC) and 3) Low Methoxyl Amidated (LMA). Within each broad category there can be a full range of possible pectins with slight differences that can be very significant for food processors (i.e. grades of calcium, pH, soluble solids, processing temperature sensitivity) and, by default, very significant for chefs.
The familiar tool of jam and jelly makers, pectin is extracted from fruits, including apples and citrus fruits. High-methoxy yellow pectin, the traditional version sold in supermarkets, requires sugar and acid to set, and forms a clear gel with no bubbles. Low-methoxy pectin sets in reaction to calcium. Pectin gels are firm and shiny.
High Methoxyl (HM) Pectin
This is the type of pectin that most people think of when they think of jam making and pectin. HM pectins are usually used to make gels (jams actually) and their gelling mechanism depends on the sugar concentration, pH and pouring/setting temperature. Because of the degree of esterification (high methoxyl) there are less locations on the molecule for calcium reactivity, i.e. calcium content in the food does not play a role in the gelling of these systems. Typical HM pectins generally require a brix level of ~65% and a pH of 3.2 - 3.4 to actually form a gel. It is possible to form gels using a rapid set HM pectin with lower brix levels (minimum 55%) but you will have to pay strict attention to the solids levels and the pH.
Typical example of a brand name:
Genu pectin type D (Low temperature set) (CP Kelco Brand)
Unfortunately, there is no specific pattern (system) to the names/numbers given HM pectins.
Low Methoxyl Conventional (LMC) Pectin
Low methoxyl pectins in general work under different conditions than HM pectins. Both LMC and LMA pectins use a different chemical method of setting up a gel that relies more on calcium, pH and processing temperature than on the soluble solids content. Given the fact that there is a lower degree of esterifcation (low methoxyl) there is more locations on the molecule for calcium reactivity. One of the big applications for LMC and LMA pectins are reduced sugar jams and jellies (between 25 and 70% soluble solids). Theoretically, you can make a jam using these pectins with as little as 10% soluble solids - of course you have to optimize the pectin, pH, calcium level, sequestrant level and processing conditions, but it is possible (if somewhat difficult). If you try to make a high solids gel with these ingredients you will have to take great caution to sequester the calcium present and control the pH, because you can easily get pre-gelation.
LMC pectins in particular are extremely sensitive to calcium and do not have a very broad calcium range in which they will work which can make choosing the right pectin an experience in trial and error.
Typical example of a brand name:
Genu pectin type LM-18 CG (medium calcium reactivity) (CP Kelco brand)
Unfortunately, there is no specific pattern (system) to the names/numbers given LMC pectins.
Low Methoxyl Amidated (LMA) Pectin
These pectins are a variation of LMC pectins where, through the addition of amide groups, the pectin becomes more robust and as such is easier to work with. If you are looking to make formulations that react with calcium this is probably the type of pectin you want to work with.
As with the LMC pectins these pectins gel with pH and calcium so you have to exercise caution to control these variables. In the case of fruit applications you have to consider that the fruits you're working with will contain a lot of calcium so you may need to sequester it (another discussion altogether).
Typical example of a brand name:
Genu pectin type LM-101 AS (lower calcium reactivity) (CP Kelco brand) Genu pectin type LM-104 AS (higher calcium reactivity) (CP Kelco brand)
Unfortunately, there is no specific patterns (system) to the names/numbers given these LMA pectins.
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