It is impossible to estimate the time taken from ingestion of the culprit food to the moment when symptoms will occur. Each person is different: in some people the symptoms begin within a few minutes while in others it can take up several hours before the onset of any manifestation. In rare cases, the symptoms may occur more than 24 hours after the food is consumed; in these situations the relation with the food as a causal factor is less clear and needs to be verified. (Do not be tempted to verify this yourself by trying the food you think is the cause of your symptoms! It could be dangerous especially if you have had an anaphylactic reaction and may lead to the wrong conclusion. Your doctor can perform the test safely and can interpret the signs correctly).
In anaphylaxis the onset of symptoms can occur within a few minutes or may take a couple of hours. However, it seems that an early onset of symptoms after consuming the food is often an indicator of a more severe reaction.