Pectin & Preserves: In the Thick of It
By Jennie Shurtleff
A century ago, the Vermont Standard ran a recipe for making peach preserves. For people living in northern climes where fresh fruit could only be enjoyed during the summer and fall seasons, finding a way to preserve the bounty so that it could be used to sweeten foods during the winter months was important.
The methods of preserving the fruit was an old one that had been around for thousands of years called sugaring. Not to be confused with maple sugaring, in which one evaporates sap from the maple tree to make either maple syrup or maple sugar, sugaring involves using sugar itself to preserve food.
Above left: Illustration by German botanist Otto Wilhelm Thomé (1885), public domain.
Above right: A recipe for peach jam printed in the Vermont Standard on October 2, 1924. Pectin (trade name “Certo”) was used to thicken the jam.
When fruit is gently heated and combined with sugar, the sugar acts not only to draw out moisture, thus aiding preservation, but also to eliminate harmful pathogens through the heat. However, sugar is only part of the secret to making the preserves, the other part is a substance called pectin.
What is Pectin and How Does It Work?
Pectin is a type of natural, soluble fiber that works as a thickening agent. The term “pectin” derives from the Greek word pektikos, which means “to congeal or solidify.” Pectin is widely utilized in culinary applications to provide a thick, satisfying texture.
Pectin is a polysaccharide—a long chain of sugar molecules found in the cell walls of fruits and vegetables. In plants, pectin serves the vital role of maintaining structural integrity and holding plant cells together.
While Henri Braconnot is credited with isolating and identifying pectin in 1825, people had long been aware of the thickening properties of certain fruits when mixed with others during cooking.
It was soon discovered that one of the best sources for pectin was apple pomace — the name given to the leftover skins, flesh, and cores of the apples after they’ve been pressed and their juice extracted.
In 1913, an American company patented a method for producing pectin, and with its rich apple harvests, America quickly became a leader in apple pectin production. More recently, Latin American companies have entered the scene, utilizing citrus peels to create citrus pectin. In both instances, pectin usually requires sugar and heat to achieve its signature thickening properties.
To extract pectin from fruit remnants, an acid solution with a pH of 1.5 to 3.5 is introduced. After a couple hours, the liquid that is extracted from the raw materials is filtered, and ethanol or isopropanol is added to the liquid. The ethanol or isopropanol causes the pectin in the liquid to solidify for easy straining. The pectin is then washed and dried. While the first commercially-available pectin appeared as a liquid product in Germany in 1908, today pectin is more commonly found in powdered form.
Though fruit pectin is primarily associated with jam, jelly, and marmalade production, its versatility extends to a variety of food products, such as serving as a gelatin substitute in gummy candies.
There is also some evidence to suggest that pectin, when taken in combination with other substances, may be helpful with certain health conditions, such as reducing the body’s absorption of cholesterol and treating diarrhea. However, further study is needed to determine possible beneficial outcomes as well as any potentially negative side effects, such as interfering with nutrient absorption.