An attempt was made to improve the process condition of red pepper seed oil refining process for removal of capsaicin and red pigment. The crude oil extracted from red pepper seed oil with hexane had deep red color and burning taste because of the contamination of red pepper seed with red pepper particle.
The method of acid value determination of crude red pepper seed oil was developed. Contaminated red pepper particles were completely removed one by one from small portions of seeds (ca. 150g). The pigments adhered to the seeds were washed out by boiling with n-hexane. The oil was extracted from the washed seed oil to determine the acid value of crude oil.
After degummed with 500 ppm of 75% phosphoric acid at 70℃, Crude oil was refined with 0.16% excess caustic lye. The alkali refined oil was bleached with the activated clay at 115℃ for 20 minutes. The deep red color of the crude oil due to the carotenoids was disappeared in the steam deodorization process which was undertaken at the high temperature of 235℃ and 1-6 mmHg vacuum for 1 hour.
The acid value of crude oil was 1.18. Lovibond color measured in 1 inch cell was 5.0 of yellow, 61.0 of red. Capsaicin content of the crude oil was 2.76 mg/ml. Acid value of finished oil with the alkali refining was 0.12, those of which without alkali refining was 0.31. Lovibond color of finished oil with alkali refining was 20.0 of yellow, 2.0 of red, those of which without alkali refining was 20.0 of yellow, 4.0 of red, 1.0 of blue. Hence, it showed that the quality of oil processed with alkali refining was better than that of oil processed without alkali refining. Capsaicin in oil was adsorbed to the activated clay, and thus removed completely from the oil with the use of 4% activated clay in bleaching process. A modified method for the quantitative determination of capsaicin in oil was developed. Capsaicin in oil was extracted with ethanol, and was separated on the silica gel plate with the solvent system of chloroform-ethylacetate(1:1).
Fatty acid composition of red pepper seed oil was examined by employing high performance liquid chromatography. The result of the liquid chromatography was similar to that of the gas chromatography. The major components of fatty acid in oil by HPLC were linoleic (78.79%), palmitic(15.27%), and oleic acid(2.93%). Red pepper seed oil is an excellent edible oil and more stable than soybean oil because of its higher content of essential fatty acid, linoleic acid, and its lower content of linolenic acid than soybean oil.
Triglycerides were predominant in the neutral red pepper seed oil. The content of triglycerides was 95.87% and that of free fatty acid was 0.78%. Monoglycerides and diglycerides did not occur in appreciable quantities.
고추씨에 25% 이상 존재하는 기름을 헥산으로 추출하였다. 고추씨에 혼입된 고추 파괴로 인해 추출된 조지방은 암적색을 띄고 매운맛을 내었다.
추출한 조지방 에서 2%의 물과 500 ppm의 인산으로 인지질을 분리해 낸뒤 과량 (0.16%) 의 NaOH 수용액으로 free fatty acid 를 중화시켜 제거 하였다. 4%의 산성 백토를 써서 탈색시키면 매운 맛을 내는 capsaicin은 완전히 흡착되어 분리 되었다. 기름의 검붉은색은 235℃, 1-6mmHg 진공상태에서 2%의 steam 으로 1 시간 동안 steam deodorization 을 하는 동안에 사라졌다.
조지방은 산가가 1.18 이었으며, 1 inch cell 에서 잰 Lovibond color 는 Yellow 가 5.0, Red 가 61.0 이었다. Capsaicin 함량은 2.76 mg/ml 이었고 인지질은 0.25%를 함유하고 있었다.
정제가 완전히 끝난 기름은 alkali refining 을 했을때 산가가 0.12, Lovibond color 는 Yellow 가 20.0, Red 가 2.0 을 나타내었으며, alkali refining 을 하지 않았을 때는 산가가 0.31, Lovibond color 는 Yellow 가 20.0, Red 가 4.0, Blue 는 1.0 을 나타내었다. 따라서 alkali refining 을 하는 것이 보다 더 좋은 효과를 보여 주었다. 정제가 끝난 기름은 매운 맛을 띄지 않았다.
검화 시켜서 얻은 고추씨의 총 지방산 함량은 79.1% 였다. 고추씨 기름의 지방산 조성은 linoleic acid 가 70% 이상 들어있어 주성분을 이루며 palmitic acid 와 oleic acid 도 상당량 함유되어 있었다. 지방산 조성을 GC 와 HLCC 로 분석하여 정량한 결과 부분적으로 약간의 차이는 있었으나 대체로 비슷한 결과를 얻었고 대두유와 비교해볼때 고추씨 기름은 리놀레닌산이 함량이 보다 적으므로 안정성 있고 필수 지방산인 리놀산이 많으므로 양질의 식용유 임을 알수 있었다.
고추씨 기름의 중성지질 성분은 triglyceride 가 95.87% 들어 있으며 free fatty acid 는 0.78%를 나타내었다.