Bioflavor; Vanillin

What are Bioflavors

Microbiological or enzymatic pathways obtain bioflavors from raw materials or substrates of natural origin (animal or plant source). They define them as natural flavors. Chemical processing synthesizes nature-identical or artificial flavors, in contrast to this. Bioflavor; Vanillin can be created artificially or naturally. Foods, fragrances, medications, and flavorings all use it. The production of a number of significant pharmaceuticals and other goods uses vanilla as a chemical intermediary.

Bioflavor; Vanillin: Characteristics, Source and Usage

Vanillin is an aldehyde compound which is a primary constituent of vanilla extract. The distinguishing scent and aroma of vanilla flavor is a characteristic feature of this compound. Its botanical source is seed pods of Vanilla planifolia plant native to Mexico. Various purposes, such as food flavoring, cosmetics ingredients, perfumes, and pharmaceuticals, make use of it. After extraction, pure vanillin has crystalline appearance with sweet and creamy odor.

Natural vs Synthetic Bioflavor; Vanillin

In early times, people obtained vanillin through physical processes such as distillation, extraction, and crystallization from seed pods of the vanilla plant. However, a rapid increase in its demand caused alleviation of production cost mainly because the plant was sensitive to climatic condition and could not be easily cultivated on larger scale. Chemical synthesis of vanillin started by using fossil fuels, oils and lignin compounds. Over time, people realized that chemically synthesized flavors are injurious to health as well as the by products from chemical synthesis tends to dwell for longer periods and cause environmental concerns (production of 160 kg of waste during processing of 1kg of vanillin). Due to these drawbacks, many researchers found bioconversion of vanillin through fermentation by microbes (bacteria and fungi).

Biosynthetic Pathways for Preparation of Bioflavor; Vanillin

To prepare vanillin, biosynthetic pathways utilize substrates like Eugenol, Ferulic acid, or D-glucose, produce from cheaper sources like clove, rice bran, and corn, respectively. Major enzymes involved in processing are Feruloyl esterases, encoded by genes FaeA and FaeB. Another enzyme, vanillin synthase, VpVAN is also essential for conversion of ferulic acid to vanillin. Microorganisms that play a role in conversion are Aspergillus niger, Pycnoporus cinnabarinus, Pseudomonas sp., Recombinant E. coli, Bacillus subtilis and Recombinant S. cerevisiae. Many other microorganisms also undergo bioengineering to produce specific enzymes associated with conversion. E. coli and Amycolatopsis sp. mutant strains, which exhibit high vanillin tolerance and possess genes associated with ferulic acid bioconversion, are numerous. These genes are Ech and Fcs genes which encodes for enoyl-CoA hydratase/aldolase and feruloyl coenzyme A (feruloyl-CoA) synthetase.

A two-step fermentation process involving two different microorganisms is the most common conversion method. During first step catabolism of ferulic acid to vanillic acid occurs in presence of A. niger (micromycete). While the second step is reduction of vanillic acid to vanillin by P. cinnabarinus (basidiomycete). Recently, bioconversion of vanillin is carried out by using glucose as substrate. Vanillin is recovered from culture medium by pervaporation. In this process, a hydrophobic membrane adsorbs the volatile solute, such as vanillin, which then recovers in vapor form.

Production of Vanillin

The production of vanillin through natural extraction from vanilla plant is 20 tons per year while its production through chemical means is 12,000 tons per year. Chemical means synthesize approximately 97% of vanillin, while plant extraction obtains only 3%. Major companies producing bio vanillin are Apple Flavour & Fragrance Group, Advanced Biotech, Evolva, Lesaffre and Solvay. Although, methods of bioconversion are widespread but these are still in initial stages requiring great insights for optimization of process to utilize cheaper substrate as well as to produce high yield of product.

References

Paul, V., Rai, N., Agarwal, A., Gautam, V., & Tripathi, A. D. (2023). Valorization of lignocellulosic waste (coconut coir) for bio-vanillin production having antioxidant and anticancer activity against human breast cancer cells (MCF-7). Industrial Crops and Products, 205, 117502.