Super-critical fluid extraction using CO₂ (SFE-CO₂) has helped create excellent flavor and aroma extracts from such things as coffee, tea and peanuts. Extraction occurs with gentle processing conditions, and, therefore, their individual, characteristic flavor identity is preserved. This process also allows for excellent control of the non-volatiles by pressure and temperature. Extracts obtained by high-pressure extraction offer the benefit of being free from solvents and provide excellent top-notes for creation of flavors. A broad spectrum of application capabilities exists for SFE-CO₂ in foods and beverages. These extracts provide perfect tools to inspire flavorists to create new, natural flavor formulations with enhanced top-notes, meeting consumer expectations.

Extraction of flavors, including tea, coffee and peanut, has historically been carried out by steam distillation or by solvent extraction, but both methods have some technical disadvantages. Steam distillation can induce rearrangement of labile molecules and can result in some undesirable aroma characteristics. Solvent extraction is not selective for aroma molecules, and, therefore, mixtures of volatile and non-volatile materials are obtained.

“These disadvantages can be eliminated with SFE-CO₂ and with numerous additional advantages added,” states Ralf Kahleyss, of the Product Development and Quality Assurance Extraction Technology department for Evonik Industries. Legal constraints due to solvent residues are eliminated. The extracts can be used quantum satis, meaning with no restrictions on use levels (when GMPs are followed). With SFE-CO₂, there are no post-extraction processing requirements; therefore, the extracts are clean, pure and unadulterated. “The low dosage of typically up to 0.1% contributes only top-notes, but no impact on texture or calories and is EU- and U.S.-organic-compliant, contributing to a healthy end-product,” adds Kahleyss. A typical dosage as a top-note in beverages for peanut, coffee or tea extracts to obtain a rich and typical aroma is 0.25g extract per liter.

SFE-CO₂ extracts boast enhanced shelflives, due to the absence of microbials and decomposed products that may kick off degradation. Additionally, their naturally high level of tocopherol antioxidants, such as in peanut extract, eliminates the need for any shelf-stabilizing ingredients. The extracts are available in both oil- and water-soluble forms.

Individual coffee or tea varieties can be finger-printed by SFE-CO₂, where their individual characteristic flavor profiles are conserved in the extracts. For example, Evonik offers a range of tea extract varieties, including black tea, green tea, jasmine, keemun, rooibos, honeybush and China white tea. Opportunities such as this are recognized for many other “origin-specific,” unique aromas.

Coffee extracts are produced with Arabica coffee beans, which possess the greatest flavor and aromatic characteristics, working well in lattes, desserts, syrups, chocolates, chewing gum, sweets and RTD coffee systems. The peanut extract adds a creamy and roasted taste sensation to nutritional bars, ice creams, baked goods, dairy, sauces, spreads and milk shakes. The tea extracts are also used in beverages, syrups and sweets. Evonik’s long-term experience in SFE-CO₂ guarantees optimal solutions, perfect technical support and product development. pf
--Elizabeth Mannie, Contributing Editor

For more information:
Evonik Industries • Trostberg, Germany
Ralf Kahleyss • ralf.kahleyss@evonik.com
www.evonik.com/extraction