Let me elaborate my question. If melamine in water produces a very milky effect then those unethical manufacturer might include it in their formulation either as a cloudifier for beverage or as an ingredient for making the beverage appears milky. For example, titanium oxide TiO2 (white colour, edible), when suspend in water, produces a very milky effect. TiO2 can be used as a cloudifier in beverage. However, since TiO2 is bearly solubity in water, it tends to settle to the bottom after some time.