olive oil

Olive oil, the pressed fruit of Olea europaea, is the cooking fat in three recipes here, and each one uses it hot. Harrak Osbao takes 60 ml for the onions, cooked over medium heat for 10 to 15 minutes until deep golden and caramelised, with about half lifted out for the garnish. Gazan Sayadiya cooks its second onion for 20 to 35 minutes in 30 ml of olive oil plus the reserved fish-frying oil. The Palestinian Molokhiya with Chicken uses 90 ml, about 6 tbsp, for the taqliya, where garlic fries for 20 seconds, just until fragrant, before chili, cilantro and spices go in and the lot is poured into the molokhiya.

The Journal's note on the olive oil sting explains what a fresh oil does in the throat. In 2003 a Unilever group separated the polyphenols of virgin oils and tasted the fractions; only one burned, and it was a single molecule, later named oleocanthal. Its receptor, TRPA1, showed up in roughly 80 cells per 0.12 square millimetres of human pharynx and in 0 per 0.05 square millimetres at the taste buds of the tongue, so the oil stings the throat and leaves the tongue alone. A bottle's oleocanthal ranges from 0.2 to 498 mg/kg with variety, harvest and freshness, and one trial found refined olive oil devoid of phenolic compounds.

Cooking is gentler on the molecule than folklore says. Heated to 240 °C for 90 minutes, oleocanthal lost at most 16 per cent by chromatography, though its measured activity fell by up to 31 per cent. Frying food is harsher: ten cycles at 180 °C stripped over 90 per cent of the phenolics when the food was not breaded. Nobody has given a person purified oleocanthal, and the one claim the European Union permits concerns blood lipids and oxidative stress, for oil with at least 5 mg of hydroxytyrosol and its derivatives per 20 g.