Terpinol

Terpineol naturally exists in turpentine oil, geraniol oil, pine needle oil, etc., and is industrially prepared with turpentine oil or isoprene as raw materials. Sulfuric acid catalyzed two-step method: under the action of 30% sulfuric acid, the pinene in the turpentine produces hydrated terpene glycol crystals and precipitates. After separation, it is dehydrated to terpineol under the catalysis of 0.2% sulfuric acid. Press distillation to get the finished product. If the phase transfer catalysis method is adopted, the effect is better. Add 33g of turpentine, 50g of 80% sulfuric acid, 0.1g of triethylbenzylammonium chloride (TEBA), and 1mL of 10% Pingping aqueous solution into the flask, and stir the reaction rapidly for 12h at 12~14℃. 25.6 g of white powdery terpene diol was obtained, and the yield was 58.7%. Add 24 g of terpene glycol and 48 mL of 0.2% sulfuric acid into the flask, and stir and react at 102 to 105°C for 4 to 5 hours. The water layer was removed by standing, and the oil layer was neutralized with 3% sodium hydroxide solution, standing, and layered to obtain 18.2 g of yellow oily liquid. Vacuum distillation, collect 190~200℃ (90kPa) distillate, get 15.5g of refined product, yield 73%. Isoprene is condensed with butenone and then reacted with Grignard reagent to prepare terpineol. Phosphoric acid catalyzed one-step method: 75mL of turpentine (containing 91% β-pinene) and 75mL of 30% phosphoric acid aqueous solution, stirred vigorously at 70℃ for 16h. The reaction solution was allowed to stand under cooling, and the water layer was separated. The oil layer was neutralized with dilute NaOH aqueous solution to neutrality. The water layer was separated, washed with a small amount of brine, and finally dried over anhydrous sodium sulfate and distilled under reduced pressure to obtain the finished product.

GB 2760-1996 stipulates the allowable food flavors. It is mainly used to prepare citrus fruits such as lemon and lime, and flavors such as peach, cherry and raspberry.