Method for preparing an oil-in-water emulsion comprising the steps: a) providing an aqueous dispersion of cellulosic fibers at a concentration ranging from 1 to 5% by weight, in which the cellulosic fibers are citrus fibers insoluble in water, in which the oil concentration is at most 1% by weight, and in which the dispersion has undergone a heating process at a temperature of at least 30 ° C； and b) optionally homogenize the dispersion of step a) in a high pressure homogenizer at a pressure of at least 250 bar； c) mixing the dispersion of stage a) or, if stage b) has been carried out, the dispersion of stage b), with 20% to 80% by weight of water, from 5% to 70% by weight of oil, from 0.1% to 5% by weight of one or more food acids, and from 0% to 10% by weight of dry matter from other edible ingredients, to prepare a previous emulsion having a pH ranging from 2 to 5； and d) homogenize the mixture of stage c) to produce the emulsion having oil droplets with a volume-weighted average geometric droplet size D3.3 of less than 10 micrometers, and in case the mixture of stage a) it has been combined with the other ingredients of the emulsion in step c), without performing step b), then homogenization is carried out in a high pressure homogenizer at a pressure of at least 350 bar, preferably at least 450 bar.Método para la preparación de una emulsión de aceite en agua que comprende las etapas: a) proporcionar una dispersión acuosa de fibras celulósicas a una concentración que oscila entre el 1 y el 5% en peso, en el que las fibras celulósicas son fibras de cítricos insolubles en agua, en el que la concentración de aceite es como máximo del 1% en peso, y en el que la dispersión se ha sometido a un procedimiento de calentamiento a una temperatura de al menos 30ºC； y b) homogeneizar opcionalmente la dispersión de la etapa a) en un homogeneizador de alta presión a una presión de al menos 250 bar； c) mezclar la dispersión de la etapa a) o, en caso de que la etapa b) se haya re
