The invention concerns a powder consisting of 0.5 to 8% by weight of water and a dry material consisting of 88 to 95% by weight of an acerola fruit dry extract and 5 to 12% by weight of magnesium, calcium, zinc, sodium or potassium hydroxide or carbonate, the method of preparing same and the applications thereof for replacing ascorbic acid and/or the derivatives of same in food products.