What I would say is when it comes to fruit and vegetables there is little or no difference except price.

I once worked with a company that markets a good proportion of the salad crop in this country. I was invited to see various stages of their growing process for iceberg lettuce. This culminated in a visit to the Fens to see the harvest.

There were five mechanised vehicles moving at a prescribed speed. At the front of each were 25 mainly eastern europeans who chopped the lettuces which were then dropped onto a conveyor belt, autowrapped and then labelled up for distribution onto waiting vehicles behind. No grading as the process produces almost uniform sizes.

I saw labels from Aldi, Lidl, Asda and Waitrose for the same product. The price differential in the shops could be almost double.