Spearmint oil

Extraction Methods:

1. Modified Steam Distillation: Weigh 10g of spearmint stem powder and place it in an Erlenmeyer flask. Add 100mL of distilled water to the flask and soak the spearmint stem powder directly for 10-12 hours. Then heat with an alcohol lamp and condense the steam using a straight condenser. The steam is mainly a mixture of water and spearmint essential oil. Distill for a total of 5 hours, then collect the colorless liquid containing spearmint oil.

2. Organic Solvent Extraction: 2.1 Crude Extraction of Essential Oil: Extraction was performed using anhydrous ethanol, ether, acetone, and cyclohexane as extraction solvents. Extraction method: Weigh 10g of spearmint stem powder and place it in a homemade filter paper bag, tie it with string, and place it in a Soxhlet extractor. Measure 100mL of organic solvent and a few boiling stones (to prevent boiling) and place them in the bag. Heat in a water bath to the boiling point of the organic solvent. Solvent vapor rises to the condenser, cools, and then drips back into a small bag containing spearmint powder. The spearmint bag, soaked in organic solvent, drips the extract back into the round-bottom flask, then into a water bath. The extraction is then repeated with rising cooling and reflux (the extract is green due to the presence of pigments). This cycle is repeated until the color of the extract in the round-bottom flask is similar to that of the fresh extract. The organic solvent with the highest essential oil yield in the above experiments is selected, and then different ratios of the two are used for extraction, aiming to find a suitable ratio that can achieve a breakthrough in extraction rate. The experimental procedure is the same as above. 2.2 Decolorization of Crude Extract After crude extraction, since some pigments are also extracted, the crude extract needs to be decolorized. The decolorization method is as follows: Pour the Spearmint oil crude extract into a beaker, add 3-4 spoonfuls of activated charcoal, then heat to boiling using an electronically controlled temperature heating mantle while continuously stirring for 15 minutes. After cooling, filter and collect the decolorized spearmint essential oil. 2.3 Evaporation of Spearmint Filtrate: Transfer the spearmint filtrate to a ground glass joint round-bottom flask. Evaporate the solvent using a rotary evaporator equipped with a vacuum pump. The vapor enters a serpentine reflux condenser and is cooled to a liquid state. Collect the vapor in a beaker until no more solvent drips. The remaining Spearmint oil can then be collected.

Content Analysis:
Determined according to Method 3 of the Aldehyde and Ketone Determination Method (OT-7), neutral sulfite method. The ketone content, expressed as carvone, was determined accordingly.

Chemical Properties:
Pale yellow or yellowish-green liquid. Relative density 0.9205-0.9340, refractive index 1.4894-1.4920, specific rotation -54° to 64°. Has a grassy aroma.

Uses:
Primarily used as a flavoring agent in candies, beverages, toothpaste, and pharmaceuticals, and as a carminative. The leaves, young branches, or whole plant are used medicinally to treat colds, fever, cough, flatulence, bruises and pain, red and painful eyes, boils, chills, numbness, and boils in children.

Pharmacological studies have shown that Spearmint oil possesses antifungal activity and anti-inflammatory activity. It is used to treat osteodystrophy, arthritis, bursitis, sinusitis, and other inflammatory conditions. Antiviral activity has also been reported.

Uses:
As a food flavoring, it is a major ingredient in spearmint-type flavorings. It can also be used directly in candies, chewing gum, and pastries. Usage dosages are: 830 mg/kg in candies; 270 mg/kg in baked goods leaves; 100 mg/kg in beverages; 100 mg/kg in alcoholic beverages; 81 mg/kg in frozen desserts leaves; and 75 mg/kg in jellies.