It’s always interesting to speculate how long it will take for some entirely new fruit to become mainstream. Some take longer than others and in this category, pitahaya, or dragon fruit as it is commonly known on retail shelves, has to be near the top of the table.

First seen from Colombia about 15 years ago or more, the market seems to have been captured by Vietnam, but other countries have also been busy. The latest arrival is from Israel, retailing under Tesco’s Just Discovered label at £2.

The difference, however, is that the variety is highlighted as having dark purple flesh, rather than its traditional shades of grey and yellow.

Another line that has built up a following over the last couple of years is sweet potatoes, sourced in the US and in some cases branded. At Tesco, they were pre-packed and sold loose at £1.35/kg. And Egypt is now adding its weight to the category, with an organic alternative at £2 for 750g.

The passion for mini vegetables seems to have passed with the fad for nouvelle cuisine and now the trend is towards either enormous value packs of green veg such as spinach or spring greens, or at the other end of the scale, crops graded to the size of cricket balls.

Marks & Spencer has already introduced iceberg and Cos lettuce, as well as twin packs of baby cabbage at £1.69.

Most vegetable arrivals look neat, clean and convenient, but the bunches of raw Heritage coloured beetroot stood out for very different reasons at Sainsbury’s. Like something from a farmers’ market at £1.80 for 500g, the selection includes distinctive golden, white and striped types.

Mixed packs of whole fruit do not usually feature strongly in fresh produce aisles, with the exception of berries and grapes. Perhaps it is something to do with the effect of too much ethylene ripening.

But Budgens has matched oranges and apples together as part of its any-three-for-£3 promotion. The varieties included in the deal are French Royal Gala apples and South African Delta Seedless citrus.