Bio vanillin refers to vanillin produced through biological processes rather than chemical synthesis. There are two primary sources of bio vanillin: natural extraction from vanilla beans and bioconversion from other natural compounds like ferulic acid. Bio vanillin has gained popularity due to its natural origin and potentially more sustainable production methods compared to synthetic vanillin. As consumers increasingly demand natural and sustainable products, the bio vanillin market is expected to see continued growth in the coming years.