Enzymatic hydrolysis for biotin extraction from animal-derived foods

Biotin exists as free or covalently bound to protein through a lysine residue. Therefore, the extraction of free biotin form is difficult in foodstuffs. Thus, the aim of this study was to investigate the extraction method of biotin in animal-derived foods by enzymatic hydrolysis (pepsin) using autoclave extraction or sonication extraction. Biotin contents of animal origin foods such as meat (beef, foreshank), fish and shells (mackerel), and egg (yolk, raw) were significantly higher in the autoclave extraction method with pepsin treatment. Therefore, these methods were selected for further applications in this study. As a result, pepsin-assisted extraction methods showed significantly higher contents of biotin compared with non-enzyme-treated samples in most of meat, fish, shellfish, and egg. The performed extraction methods in this study were validated according to AOAC guideline. An excellent linearity of biotin standard was observed over R2=0.999. All analytical methods for biotin showed the acceptable accuracy (97-101% recovery) and the precision (1-4% RSD for the repeatability, 0-4% RSD for the reproducibility). The limits of detection and quantification for biotin analysis were 0.009 and 0.024 μg/100 g, respectively. These results may be useful for providing reliable data about the biotin contents in commonly consumed foods in Korea.