I HAVE just returned (how fortunate am I?) from a three-month visit to New Zealand. Prior to my departure, I left a basic "basket" of food for my great nephew, who was going to stay in my flat on student medical placement whilst I was away. The food was all in the fridge, apart from four grapefruit which I left in a bowl in the (warm) kitchen. Imagine my surprise when, on my return, I found four grapefruit, which I proceeded to enjoy for my breakfasts.

It did occur to me that they were slightly wizened, but nevertheless delicious. It took me to day three to realise these were the same grapefruit which I had left. What kind of preservatives are used on citrus fruits to prolong their lives to such an extent? And on what other food? It's scary. I look forward to my visit to my lovely organic veggie lady supplier, whose food does go off - eventually, if not used.

Lesley Mackiggan,

61 Kelvin Court, Glasgow.