Composition and Nutritional Value of Acid Oils and Fatty Acid Distillates Used in Animal Feeding

• Published in: Animals (Basel) Vol. 11; no. 1; p. 196
• Main Authors: Varona, Elisa, Tres, Alba, Rafecas, Magdalena, Vichi, Stefania, Barroeta, Ana C, Guardiola, Francesc
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.01.2021; MDPI
• Subjects: acid oils; animal feed; By products; Byproducts; Composition; Crude oil; Distillates; Distillation; Edible oils; Energy value; fat by-products; Fatty acid composition; fatty acid distillates; Fatty acids; Feeds; Food chains; Guidelines; Impurities; Ingredients; Lipids; Moisture; nutritional value; Nutritive value; Oils & fats; Petroleum refineries; Petroleum refining; Polymers; poultry; Refining; Standardization; Sustainability; Variability; animal feed; poultry; fatty acid distillates; acid oils; nutritional value; fat by-products; MIU value; energy; pig
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani11010196

Acid oils (AO) and fatty acid distillates (FAD) are oil refining by-products rich in free fatty acids. The objective of this study is their characterization and the identification of their sources of variability so that they can be standardized to improve their use as feed ingredients. Samples (n=92) were collected from the Spanish market and the MIU value (sum of moisture, insoluble impurities, and unsaponifiable matter), lipid classes, fatty acid composition, and tocol content were analyzed. Their composition was highly variable even between batches from the same producer. As FAD originated from a distillation step, they showed higher free fatty acid amounts (82.5 vs 57.0 g/100 g, median values), whereas AO maintained higher proportions of moisture, polymers, tri-, di-, and monoacylglycerols. Overall, the MIU value was higher in AO (2.60-18.50 g/100 g in AO vs 0.63-10.44 g/100 g in FAD), with most of the contents of insoluble impurities being higher than those in the guidelines. Tocol and fatty acid composition were influenced by the crude oil's botanical origin. The calculated dietary energy values were, in general, higher for AO and decreased when a MIU correction factor was applied. The analytical control and standardization of these by-products is of the outmost importance to revalorize them as feed ingredients.