Chocolate Slices with Banana Crisps: Aki Kamozawa and H. Alexander Talbot

Pectin is probably most recognizable to home cooks as the ingredient that thickens jellies and jams and gives them that smooth, sticky texture. Pectin is an indigestible soluble fiber which, when combined with water, forms a colloidal system and gels. It has a wide range of uses. It can be found as a gelling, thickening or stabilizing additive in food, an ingredient in laxatives, a demulcent in throat lozenges, and vegetable glue for cigars.

Pectin is found naturally occurring in various forms of plant life, where it helps to bind cells together. In spite of the fact that it is widely occurring, there are only a few specific sources used to manufacture pectin for food purposes. Traditionally apple peels and cores were the primary source of pectin for making jellies and preserves. The liquid extract was preserved with sulfur dioxide and sold in bulk. As the commercial industry grew, so did the need for a more stable and easily transportable source of pectin. Citrus peels, a by-product of the juice industry, became a major resource for manufacturing solid pectin products. Pectin derived from apple and citrus sources are admirably suited to our culinary purposes.

Pectin is soluble in cold water. Once dissolved it forms a viscous solution. When used in powder form, it must be dispersed rapidly as it easily forms lumps encased in a thin gel layer. This outer layer makes the lumps very difficult to dissolve and eliminate from your final product. The best ways to utilize pectin in its powdered form is by shearing it into your mixture using a standing blender, or by combining it with other soluble powders, like sugar or salt, before whisking it into your liquid ingredients. Pectin dissolves much more slowly in high-sugar solutions, so those can also be whisked into a syrup, which can then be diluted and gelled.

Pectin used for cooking is divided into two categories, high-methoxyl (HM) and low-methoxyl (LM). HM pectin is most commonly used to create fruit preserves. It requires the presence of sugar and specific levels of acidity. The amount of acid in your base solution will directly affect the setting time of the pectin. There are two types of HM pectin: rapid-set and slow-set. Rapid-set HM pectin is often used for jellies that have ingredients suspended inside the gel structure, such as chunky marmalades or hot pepper jelly, while slow-set HM pectin is often used for clear jellies like apricot or grape.

LM pectin requires the presence of calcium to activate the gelling process. Gelation is affected by many factors. There are minimum levels of calcium needed to create a gel. Above that level, the gel strength will increase rapidly, until it reaches maximum saturation, after which point adding additional calcium will cause the gel strength to decline. A sequestrant can be used to control the availability of the calcium present; as sequestrant levels increase, the system will gel less easily and at lower temperatures. A general rule of thumb for pH is that as acidity decreases, pectin with a higher reactivity level will be needed to form a gel. LM pectin is often used to produce low- or no-sugar jellies. Pectins have a complementary relationship with dairy products and are able to utilize whey as a source of calcium, enhancing their innate capabilities for gelation, emulsification, and the ability to produce stable foams.

Amidated LM pectin (LMA) is pectin that has been treated with ammonia, which moderates the bonds formed between the amide groups and the calcium ions. LMA is also more tolerant of fluctuations in the levels of calcium present in the base solution. Amidated LM pectin requires less calcium than conventional LM pectin to gel. It is more thermally reversible than untreated LM pectin and has the ability to re-form after shearing.

From a culinary standpoint, we like pectin because it creates gels with a smooth, creamy texture and great flavor release. It can be used to create fruit and vegetable terrines, water gels, and low-sugar and low-fat applications. All that and it's a vegetarian product. We've included a couple of recipes using LM pectin and LMA pectin so that you can begin experimenting with the possibilities.