A lot of things do contribute to food prices, not just supermarket greed.
Firstly we can all see the price of petrol rising, that reflects the cost of oil. Planes boats cars = shipping. So the manufacturers and freighters have to bear those costs also.
Secondly harvests - a few years ago it rained a lot in South America so coffee went through the roof. Ok you could have bought lesser brands grown elsewhere in the world but to me coffee is a luxury, I want to drink nice coffee.
Wheat at the moment is through the roof due to poor harvests. As my baker said to me, I can buy substandard German flour or I can continue to import Canadia, do you want nice bread or not? he had a point. Nice bread is another thing I insist on - I don't buy value bread, or freeze bread, bread must be fresh and always kept at room temperature - t'is Hollys Law! but wheat prices also impact on pasta
Ground nut (peanut) is used in most cooking processes - again most of this is grown in Africa, dependent upon where, you are faced with crop failure, civil wars and so forth - thus the price is reflected.
Rice, again, tends to come from countries that experience vast changes in weather conditions - the bulb of Africa, South America and Thailand. labout is cheap but shipping isnt.
Even looking at animals - you have to feed them - price of feed is reflected. Also to maintain herds you need vets, drugs, innoculations, shipping licences.
A large proportion of our meat is slaughtered in France. Again there is a large proportion of abatoirs in France that are halal - there is a big EU trade in halal meat. Again, the majority of meat in schools, hospitals, public sector canteens has come via this route. It is more labour intensive