Grape Seed

A grape berry normally contains one to four seeds, which are small, pear-shaped, hard and brown, usually 4 to 6 mm long, with a pointed end and a groove on one side. The seeds are bitter and astringent when chewed because of tannins in their coat. They are not usually eaten whole, although some people swallow them with the fruit. Commercial forms include cold-pressed or refined grape seed oil, which is pale green to yellow and almost neutral in flavour, and powdered extract sold in capsules. Ground seed flour is also produced in small quantities from pomace, the solid residue left after pressing grapes.

The common grape vine was domesticated in the Near East and Caucasus region roughly 8,000 years ago, and archaeological finds of seeds help researchers trace its early cultivation. From there the vine spread through the Mediterranean and later through Europe, the Americas, South Africa and Australia. Vitis is the Latin word for vine, and vinifera means wine-bearing. The English word grape comes through Old French from a word meaning hook or cluster, related to the tool used to harvest the fruit. The word pip is a shortened form of pippin.

Grape pips have been recovered at archaeological sites across the Near East and Europe, and are among the most important clues about the history of winemaking, since seed shape can distinguish wild from cultivated vines. Pressing and drying of grapes for raisins and wine left large quantities of pomace, which farmers used as animal feed, fertiliser and fuel.

Grape seed oil as a food product developed mostly in the twentieth century. In Europe, especially in Italy, France and Spain, wineries began pressing seeds from pomace in the 1930s to 1940s when other oils were scarce. It gained popularity because of its high smoke point relative to olive oil and its neutral taste, which fits restaurant kitchens.

In the late twentieth century, researchers in France reported on the proanthocyanidins in the seeds, and extracts were sold as supplements. Today grape seed oil is produced in Europe, South America, and elsewhere, and the seed has become an example of a circular economy approach in which waste from one industry becomes another's raw material.

Grape seed oil is used for sauteing, frying, salad dressings and mayonnaise because of its light taste and moderate smoke point, though refined versions are more stable under heat. It is also a common carrier oil in massage and cosmetics. Seed extract, standardised for polyphenols, is sold as a supplement. Some bakers use pomace flour in breads and snacks. Whole seeds may be crushed into spice blends or tea in experimental cuisine, and the leftovers are used in animal feed. Oil should be stored away from heat and light, since it is high in polyunsaturated fats that oxidise.

Grape seed oil is rich in linoleic acid, an omega-6 fatty acid, and contains vitamin E, but it is low in omega-3 fats, so it is best used as part of a balanced fat intake. Seed extracts contain proanthocyanidins, which have been studied for blood pressure, circulation and antioxidant effects. Some trials show modest changes, but results are inconsistent and the quality of studies varies, so the evidence is not conclusive for treating any condition.