Pectin

Pectin is a natural substance found in the cell walls of plants. Its name comes from an Ancient Greek word meaning "congealed" or "curdled," because it helps things thicken and gel. The main building block of pectin is a type of sugar called galacturonic acid, which was first identified by a scientist named Henri Braconnot in 1825.

In everyday life, pectin is most familiar as the ingredient that makes jams and jellies set into a firm, sweet spread. It is made from citrus fruits and is a white-to-light-brown powder. Besides sweets, pectin is also used to stabilize fruit juices and milk drinks, and it can even be found in some medicines.

Pectin is also important for our health because it acts as a type of dietary fiber. It helps keep our digestive system working well and can be found in many fruits and vegetables. This useful plant material shows how nature provides ingredients that are both tasty and good for us.

Biology

Pears, apples, guavas, quince, plums, gooseberries, and oranges and other citrus fruits contain large amounts of pectin, while soft fruits, like cherries, grapes, and strawberries, contain smaller amounts. Typical levels of pectin in fresh fruits and vegetables include:

• Apples, 1–1.5%
• Apricots, 1%
• Cherries, 0.4%
• Oranges, 0.5–3.5%
• Carrots 1.4%
• Citrus peels, 30%
• Rose hips, 15%

Pectin is found in the cell walls of plants and helps bind plant cells together. As fruits ripen, pectin breaks down, which makes the fruit softer. In our diet, pectin acts like a soluble fiber, helping to lower cholesterol levels and support gut health. It is found in many fruits and vegetables and is commonly used in foods like jams and jellies.

Chemistry

Pectin is a special kind of substance found in plant cell walls, made mostly of a sugar called galacturonic acid. It helps plants stay firm and is used by people to make foods like jams and jellies thicker and smoother.

Pectin can change a little depending on where it comes from, but it usually has parts that can link together with help from substances like calcium. This lets it form gels, which are the thick, jelly-like textures in many foods. There are different types of pectin, some working better in sugary conditions and others needing calcium to work well.

Structural features of various pectins
Section of the pectin main chain: Poly-α-(1→4)-galacturonic acid.
Partially esterified section of the pectin main chain
Rhamnogalacturonan: backbone with a "kink" due to incorporated rhamnose

Production

Pectin is made from dried citrus peels and apple pomace, which are left over from making juice. These materials are treated with hot, acidic water to pull out the pectin. The liquid is then filtered, and alcohol is added to make the pectin settle out. Finally, it is washed and dried to create a powder.

Scientists are also working on newer, "green" methods to make pectin that use less harmful chemicals and energy. These methods include using special enzymes or high-frequency sound waves to help extract pectin more gently. While these new techniques are still being tested, they could make pectin production more sustainable in the future.

Uses

Pectin is mainly used as a gelling agent, thickener, and stabiliser in food. It helps give jams and marmalades their jelly-like consistency and can also be found in gelling sugar for home jam making. Different types of pectin are used depending on the food — high methoxyl pectins are used in traditional jams, while low methoxyl pectins work well in low-sugar or dairy products.

Pectin isn’t just for food. It can help with constipation and diarrhea when used in medicines and is also used in cosmetic products and wound healing preparations. It has even been used to help keep printed maps clear and readable.

Legal status

Pectin is considered safe for use in food. In the European Union, no daily intake limit has been set for two types of pectin, E440(i) and Amidated Pectin E440(ii), because it is seen as safe. The European Food Safety Authority checked pectin again in 2017 and found no safety concerns for people using it.

In the United States, pectin is also recognised as safe to eat. It is known by the number 440 in the International Numbering System. In Europe, it is listed as E440(i) for non-amidated pectins and E440(ii) for amidated pectins. Rules about its quality and use are set by laws in many countries and international groups.

History

Pectin was first discovered and described in 1825 by Henri Braconnot. People have used pectin to make jams and marmalades for a long time, even before they knew exactly what it was. To make good jams from fruits that didn’t have much pectin, they added pectin from other fruits or extracts.

During the Industrial Revolution, makers of fruit preserves started using dried apple pomace to get pectin. In the 1920s and 1930s, factories were built to extract pectin from apple pomace and later from citrus peel. Pectin is now usually sold as a dried powder, which is easier to store and use than liquid.