It may come as a surprise to learn the the tiny black seeds of the delicious pavlova staple are also an excellent source of a cosmetic oil.

Passionfruit belongs to the Passifloraceae family, which originated in tropical America. The most cultivated species are the yellow passionfruit (Passiflora edulis f. flavicarpa), purple passionfruit (Passiflora edulis), and sweet passionfruit (Passiflora alata). The oil content of the yellow passionfruit seeds is 30 percent, comparable to soybean seed. It contains significant levels of unsaturated fatty acids (88 percent), primarily linoleic acid, (73 percent) and oleic acid (14 percent), along with palmitic and stearic acids.

Nourish and smooth

Polyunsaturated linoleic acid is one of the omega-6 family of essential fatty acids. Because the essential fatty acids in the oil can penetrate the skin, it means that the antioxidants it also contains can be absorbed deep down. Research also shows that, taken internally, it helps maintain cell-membrane health. A deficiency may lead to dry hair, hair loss, dry dandruff and weak, rough, and coarse hair. Linoleic acid helps guard against loss of hair moisture, improves its elasticity, and can penetrate the hair follicle to provide nourishment for hair growth. A popular addition to cosmetics, linoleic acid also hydrates and smooths skin, and may – thanks to its anti-inflammatory properties - reduce acne.

A study published in Molecules indicates passionfruit seed oil has high antioxidant activity, due to the combination of tocopherols (vitamin E) and phenolic compounds. The major tocopherols in the oil are delta and gamma, which according to research by Schmidt and Pokorný are more active antioxidants than alpha and beta tocopherol. Delta tocopherol is the predominant tocopherol (279 mg/kg), substantially higher than levels found in peanut oil (13 mg/kg), sunflower oil (9 mg/kg) and canola oil (6 mg/kg) oils. Because each antioxidant is effective only against particular kinds of free radicals, this means each type of tocopherol has a different antioxidant range. Studies confirm that mixed tocopherols are more effective than alpha tocopherol alone in quenching free radicals.

The concentration of phenolic compounds in passionfruit seed oil is comparable to that found in oils extracted from blueberry, raspberry and blackberry seeds. Phenols may protect the skin by inhibiting the enzymes that break down collagen, one study suggests, although another found only a small portion of phenolics is transferred to the oil during extraction. Passionfruit oil has documented anti-inflammatory properties and, at least in animal tests, can stimulate production of fibroblasts, the cells that make collagen. Used on the hands, passionfruit seed oil may also strengthen weak, fragile nails. The high linoleic acid content makes for an oil that is lighter with a thinner consistency, but still has the power to nourish and protect skin. However, ageing or very dry skins may obtain greater benefit from heavier, oleic acid-rich oils, such as olive oil.

Finally, there’s a significant environmental side benefit to using passionfruit seed oil. The commercial extraction of passionfruit juice for the consumer juice market, and for use in food products like ice cream, confectionery, and soft drinks produces thousands of tonnes of agricultural waste in the form of seeds and skins. Extracting the oil from the seeds dramatically reduces this waste.

Naturopath Dr Sandi Rogers ED.D., ND is a life member of the Australian Traditional Medicine Society.