I. Camellia Fruit Harvesting and Pretreatment: From Fresh Fruits to Qualified Camellia Seeds
The timing of camellia fruit harvesting and processing methods directly affect the quality of camellia seeds, serving as the source guarantee for subsequent oil processing.
1. Camellia Fruit Harvesting
Camellia fruits generally ripen around Frost’s Descent (October-November). The ripeness criteria are: the peel changes from blue-green to yellowish-brown or reddish-brown, the fruit shell cracks slightly to expose brown camellia seeds, and the oil content of the seeds reaches its peak at this time.
Harvesting method: Manual picking is adopted. Avoid hitting branches violently with bamboo poles to prevent damage to tea trees and fruiting branches for the next year. Transport the harvested fruits in a timely manner to avoid heat accumulation and mold growth due to piling.
2. Camellia Fruit Shelling and Drying
Spread fresh camellia fruits in a well-ventilated and sunny area for natural drying for 3-5 days, turning them regularly during the period. After the fruit shells crack, peel them manually to separate the camellia seeds (with seed coats). After shelling, remove damaged, insect-infested, and moldy camellia seeds, retaining high-quality seeds that are plump and uniform in color.
3. Camellia Seed Shelling and Screening
The dried camellia seeds are shelled using a sheller to remove the outer shell (the outer shell is a brown hard shell, and the inner seed coat is a thin white skin). The rotational speed of the sheller is controlled at 150-200r/min to avoid damaging the camellia kernels.
Through air separation (removing light seed coat debris), screening (using a 1.5-2.0mm sieve to separate camellia kernels from unshelled fruit shells), and manual sorting (removing shrunken, insect-infested, and discolored camellia kernels), finally obtain camellia kernels with a purity of ≥99% and no impurities, preparing for subsequent pressing.
II. Camellia Kernel Processing: From Raw Material to Crude Camellia Oil
- Spiral Pressing: Pressure 25-35MPa, rotational speed 20-30r/min, press chamber temperature ≤120℃, oil yield 26%-28%, residual oil rate in cake ≤5%.
- Crude Oil Initial Filtration: Filtered through a 100-120 mesh filter, flow rate 5-8L/min, suspended impurities ≤0.15%.
- Cooling and Storage: Cooled to below 25℃ by a plate cooler (cooling rate 5℃/min), temporarily stored under inert gas protection (oxygen ≤3%). The acid value of crude oil ≤2mg/g, moisture ≤0.2%.
III. Moderate Refining of Crude Camellia Oil: From Crude Oil to Finished Camellia Oil
- Degumming Treatment: Add 3%-5% of 80-85℃ distilled water at 60-65℃, stir at 30-50r/min for 20-30 minutes, and stand at 25℃ for 4-6 hours. Phospholipid content ≤0.05%.
- Precision Filtration and Cooling: Pressure filtration with a 300-400 mesh filter cloth (pressure 0.3-0.5MPa), light transmittance ≥95%, impurities ≤0.02%; cooled to 20-25℃ (stirring at 15-20r/min).
- Finished Product Storage: Stored in 304/316L stainless steel tanks, under a dark and dry environment at 10-20℃, protected by nitrogen (purity ≥99.5%). Acid value and peroxide value are tested weekly, with a shelf life of 18-24 months, complying with GB/T 11765-2021 Grade 1 standard.