Promoting protein digestion is the primary function of feed acidifier, and the prerequisite for its realization is that the amount of H+ provided by acidifier must be "enough", so the acidity of acidifier is an important technical index of feed acidifier.
Expression of acidity of acidifier
There is no unified way to express the amount of acid in feed acidifier. At present, it is commonly used to express the amount of acid in 1% aqueous solution by pH value, total acid content, total acidity and total acid (calculated by lactic acid), with different emphasis.
The pH value of 1% aqueous solution refers to the pH of an aqueous solution after 1g acidifier is dissolved in 100g water, corresponding to the H+ concentration in the water at this time. Due to the weak electrolyte and dissociation equilibrium, the pH value of 1% aqueous solution is related to the dissociation constants of various acid raw materials, but not directly related to the H+ provided by the acidifier.
The total acid content refers to the sum of the proportion of all acid raw materials in the acidifier finished product, indicating the real "acid" in the finished product excluding the carrier and auxiliary materials, which is often quantitatively determined by HPLC method. However, the total acid content does not really reflect the amount of H+ in the final product of acidifier due to the huge difference in the amount of H+ provided by different acid raw materials.
Total acidity refers to the total amount of all acidic components in the acidifier, including the undissociated acid and the dissociated acid. In terms of determination, we refer to the determination method of total acid in food (GB/T 12456-2008), which is essentially a measure of the total amount of H+, reflecting the amount of H+ contained in the acidifier.
Total acid (XX acid) is a transformation of total acidity, is the food industry expression habit. Depending on the acid in the food, one of the major organic acids is usually measured (usually lactic acid) as follows, for example, "by lactic acid", multiplied by the conversion factor K for lactic acid). The total acid (XX acid) is not the true amount of this organic acid. As feed enterprises are concerned about the organic acid content represented by lactic acid in acidifiers, the expression mode of "total acid (measured by lactic acid)" is produced.