The list of possibilities is still fairly short: https://www.ams.usda.gov/rules-regulations/be/bioengineered-foods-list https://www.ams.usda.gov/rules-regulatio

The list of possibilities is still fairly short: https://www.ams.usda.gov/rules-regulations/be/bioengineered-foods-list https://www.ams.usda.gov/rules-regulations/be/bioengineered-... If you're looking at the ingredients: canola/soy/corn/"vegetable" oil, or (high fructose) corn syrup, or sugar that doesn't explicitly say cane sugar. If the pineapple is purple, the GMO ingredient should be obvious.