Complex sentence: The spread of maize cultivation in the Americas was accompanied by the adoption of the nixtamalization process, and traditional and contemporary regional cuisines (including Maya Cuisine, Aztec cuisine, and Mexican cuisine) included, and still include, foods based on nixtamalized maize.
Split into simpler sentences: The spread of maize cultivation in the Americas was accompanied by the adoption of the nixtamalization process. Traditional and contemporary regional cuisines (including Maya Cuisine, Aztec cuisine, and Mexican cuisine) included, and still include, foods based on nixtamalized maize.