Believe it or not, there is little research telling us what food to introduce first.
Most recommendations have been common-sense recommendations and have survived years and years of mothering. It doesn’t really matter whether you introduce vegetables before fruit or meat last. What does matter is that your baby receives a good iron and zinc source at 6 months old, especially if breastfeeding, and this can come from fortified cereal, meat, or mashed beans. Also, it is important that you monitor your baby every 2-3 days for adverse reactions to any new food, which may indicate a food allergy.