Abstract
Fishes usually have low levels of acid secretion in the gut as compared to mammals. Inclusion of organic acids in their diet reduces the pH in the gut. This lowering of pH increases the phytate hydrolysis, kills the pathogens, decreases the rate of gastric emptying and improves mineralization and nutrient absorption. Among the organic acids, citric acid (CA) has been used extensively for diet acidification due to its unique flavor and high buffering capacity. It has great potential to replace fish meal (up to 70%) with plant based protein sources. Being a strong chelator of calcium and phosphorus, CA enhances the phytate hydrolysis. It improves the bioavailability of minerals by solubilizing the bones and competing with other chelators. It also increases the endogenous as well as exogenous phytases efficiency by providing an optimum pH in gut. Besides, it acts as antimicrobial agent and stimulates feeding in fish. Purpose of this review is to appraise the applications of citric acid supplementations in fish feed and to highlight its role in improving the growth performance, nutrient digestibility, minerals availability and phytase efficacy. (C) 2015 Friends Science Publishers