Kiwifruit Seeds

Kiwifruit grows on a vigorous deciduous woody vine with large heart-shaped leaves. The oval fruit has a fuzzy brown skin and bright green flesh, with a pale core ringed by hundreds of small black seeds. The seeds are about 1 to 2 mm long, flattened and oval, with a hard coat that is crunchy but easy to chew. They have a faintly nutty, mild flavour that is noticeable mainly as texture. Whole seeds are eaten with every bite of the fruit, and the seed fraction recovered from juice or puree production is dried and cold-pressed for oil. Seeds can be sown for plant breeding, but cultivated vines are propagated by grafting or cuttings to keep the variety.

Kiwifruit species are native to the mountainous forests of southern and central China, where the plant has grown wild for centuries and was known as yang tao or mihoutao, meaning macaque peach. The fruit was introduced to New Zealand in the early twentieth century, where it was renamed Chinese gooseberry, and then kiwifruit in the 1950s to 1960s after the flightless bird, as a marketing name. The scientific genus name Actinidia comes from a Greek word for ray, referring to the radiating styles of the flower.

Chinese texts mention the wild fruit more than a thousand years ago, but it was not cultivated systematically in China until recently. In 1904, seeds brought from Yichang in China were planted in New Zealand by a school principal, Isabel Fraser, and by 1910 the first vines fruited, leading to the first commercial plantings in the 1920s. The Hayward variety, selected by Hayward Wright in the 1920s, became the main cultivar worldwide. Exports expanded in the 1950s and 1960s, and the renaming to kiwifruit helped avoid trade tariffs on berries, and promoted the product to American consumers. Italy, Chile, Greece, France and later China and other countries entered production, and China now leads the world. Golden and red kiwifruit varieties were later developed. Alongside the fruit trade, processing by-products including seeds have attracted attention for oil, a source of omega-3 alpha-linolenic acid, used in cosmetics and, in small amounts, as a nutritional oil.

The seeds are eaten whole with the fruit, adding crunch to fruit salads, smoothies and yoghurt. Dried kiwi seeds can be used in baking and as a decorative topping, much as poppy seeds are. Cold-pressed kiwi seed oil is used in skincare and sold as a dietary oil in some markets. Seeds are separated from pomace during juice making and used for oil extraction. Gardeners rarely sow them for fruit since seedlings vary and take years to fruit.

Kiwi seed oil is notably high in alpha-linolenic acid, a plant omega-3 fatty acid, but the amount that people actually consume from seeds in the fruit is small. Kiwifruit as a whole has been studied for vitamin C content and for its effect on regularity, with several trials showing that eating a couple of fruits daily can ease constipation. Evidence specific to the seeds is limited.