초록 ▼

□ 연구 배경
○ 천연물로부터 유효성분을 추출할 수 있는 환경친화적 대체 기술 필요
- 유기용매 추출의 경우 제품 내 잔류용매 문제가 있으며 분리정제, 농축, 건조 등의 다단계 공정이 요구됨.
- 잔류용매가 존재하는 추출물을 화장품 원료로 사용하기 어렵고, 다단계 공정으로 인한 제품의 원가 상승 및 추가 비용 발생
- 유기용매 추출의 경우 표적 성분에 대한 선택도가 낮아 추출물 내 유효성분의 순도가 낮음
- 잔류용매가 없으면서 유효성분의 추출효율이 높은 환경친화적 기술로 초임계 유체 추출 공정기술에 대한

□ 연구 배경
○ 천연물로부터 유효성분을 추출할 수 있는 환경친화적 대체 기술 필요
- 유기용매 추출의 경우 제품 내 잔류용매 문제가 있으며 분리정제, 농축, 건조 등의 다단계 공정이 요구됨.
- 잔류용매가 존재하는 추출물을 화장품 원료로 사용하기 어렵고, 다단계 공정으로 인한 제품의 원가 상승 및 추가 비용 발생
- 유기용매 추출의 경우 표적 성분에 대한 선택도가 낮아 추출물 내 유효성분의 순도가 낮음
- 잔류용매가 없으면서 유효성분의 추출효율이 높은 환경친화적 기술로 초임계 유체 추출 공정기술에 대한 연구가 필요함.
- 초임계 유체 추출 공정은 거의 모든 범위의 분자량에 대한 유효성분 추출이 가능한 것으로 알려져 있으며, 다품종 소량생산의 특성을 갖는 고부가가치 기능성 화장품 소재 산업에 매우적합한 추출 기술임.
○ 본 연구에서는 보리순에서 고순도 항산화제 유효성분을 효율적으로 추출할 수 있는 고효율 초임계 유체 공정을 연구하고, 추출물을 함유한 항산화 화장품 제형 연구를 통해 기능성 천연 화장품 소재를 개발하고자 함.
□ 주요 연구성과
○ 초임계 유체 전처리 추출공정 개발
- 초임계 유체 전처리 공정 장치 구축 및 공정 최적화(2014년 12월 2편의 관련 논문 투고 예정)
- 유효물질의 추출을 최소화하면서 색소를 제거할 수 있는 초임계 유체 전처리 공정 기술 개발
- “초임계 이산화탄소와 유기용매를 이용한 chlorella vulgaris 오일의 추출” (초임계 유체 공정 기술 관련 연구 결과를 논문 게재)
○ 초임계 유체 single-step 추출 공정 개발
- Single-step 초임계 추출 공정 장치 구축 및 공정 최적화
- Mini-pilot 규모(1.2 L)의 추출 장치 구축 및 scale-up을 위한 engineering data 확보
○ 초임계 유체 double-step 추출 공정 개발
- double-step 초임계 추출 공정 중의 친수성 유효성분 대체 물질인 HP-β-CD를 이용하여 초임계 유체를 이용한 미립자 형태 건조 공정 조건 확립(논문 게재)
- 초임계 유체 double-step 추출 공정에서 미립자 형태 건조공정 조건 확립(12월 논문 투고 예정)
- 색소 제거를 위한 전처리/유효성분 추출/추출액의 건조 공정을 통합한 초임계 유체 복합 연계 공정 기술 개발(특허 출원 10-2014-0050407)
- 공용매로 변형된 초임계 유체를 이용한 미립자 형태 건조 공정 장치 구축 및 최적 조건 확립
- 주정추출과 같은 유기용매 추출을 연계한 초임계 유체 미립자 형태 건조 공정 기술 개발(특허 출원 10-2014-0125560)
○ 색소 저함유 항산화물 추출을 위한 초임계 유체 공정기술에 관한 노하우(유상기술이전 완료)
○ 보리순 추출물의 안전성 평가
- 보리순 추출물 내 잔류용매 농도 허용 기준 이하 달성 (미검출)
- 세포독성 평가 시 세포의 독성이 거의 없는 것으로 확인됨.
○ 보리순 추출물을 함유한 화장품 제형 개발
- 가혹조건에서 2개월 동안 보리순 추출물 내 항산화제 안정성 확인
- 보리순 추출물 함유 화장품 제형의 안정성 확인 (식약처 안전 기준 범위 내)
○ 보리순 추출물 함유 무방부제 에센스 제형 개발
○ 화장품 제형의 피부 안전성 평가
- 보리순 추출물 함유 무방부제 에센스의 인체 첩포 시험 결과 저자극 범주의 물질로 판정
□ 파급효과
○ 기존의 천연 기능성 소재 생산에서 요구되는 복잡한 분리정제 공정을 단순화 할 수 있어 에너지 절감 효과와 생산성 향상 효과가 기대됨.
○ 초임계 유체를 이용한 double-step 추출 공정의 경우 기능성 천연물 소재를 추출하여 미립자 형태로 제조할 수 있기 때문에 폐흡입 제제 형태의 천연 추출물 신약의 개발에 활용할 경우 우수한 결과를 얻을 수 있을 것으로 예상됨.
○ 보리순 뿐만 아니라 기능성 효능을 갖는 다양한 천연물로부터 유효성분을 추출하여 화장품, 의약품 등의 소재로 사용하는 관련 산업에 공정 인프라를 제공할 수 있음.
○ 본 연구에서 개발된 초임계 유체 미립자 형태 건조 공정을 주정추출과 같은 유기용매 추출과 연계하는 경우 고품질의 천연 추출물 소재 개발 분야에서의 파급효과가 매우 클 것으로 예상됨.

Abstract ▼

Flavonoids are plant-based compounds with powerful antioxidant properties found in a variety of fruits and vegetables. Young barley leaves are reported to contain a significant amount of flavonoids such as isovitexin and saponarin as well as natural pigments such as chlorophyll and beta-carotene. Ho

Flavonoids are plant-based compounds with powerful antioxidant properties found in a variety of fruits and vegetables. Young barley leaves are reported to contain a significant amount of flavonoids such as isovitexin and saponarin as well as natural pigments such as chlorophyll and beta-carotene. However, the presence of natural pigments in the final extract may not be helpful to the preparation of cosmetic formulations.
Conventional methods such as organic solvent extraction and hot-water extraction have been widely used to extract flavonoids from various plants. However, these methods require the use of large amounts of organic solvents and/or high energy consumption. Furthermore, public health, environmental, and safety issues are the major concerns in the use of organic solvents in extraction processes. To overcome these limitations, a variety of processes involving extraction with supercritical fluids have been developed and are regarded as a viable extraction technology that meets the product quality and safety requirements.
The main purpose of our study was to develop a high-efficiency supercritical fluid extraction technology for production of cosmeceutical ingredients from young barley leaves. As a preliminary study, solvent extraction experiments were performed to select organic solvents, suitable for the extraction of natural pigments and/or antioxidants. Ethanol was found to be very effective for pigment extraction, while methanol was most effective for antioxidant extraction.
Two different extraction techniques, solvent extraction and supercritical carbon dioxide (SCCO₂) extraction, were investigated to compare their extraction efficiency of antioxidants and pigments from young barley leaves. Using pure SCCO₂, antioxidants and pigments were not extracted significantly from barley leaves. As a pretreatment extraction process, a supercritical fluid extraction was carried out using SCCO₂ modified with the organic solvents, selected in the preliminary study, in order to improve the pure SCCO₂ extraction process. Compared with solvent extraction, the purity of antioxidants and pigments was found to increase about 2.6 times when SCCO₂ was modified with 95% aqueous ethanol solution. It was also confirmed that the EtOH-modified SCCO₂ process can be used to extract significant amounts of pigments from young barley leaves while minimizing the extraction of antioxidants.
The single-step supercritical fluid extraction process was developed to maximize the extraction of antioxidants from young barley leaves, while minimizing the extraction of pigments. The single-step process using MeOH-modified SCCO₂ was found to be very effective for extraction of antioxidants from young barley leaves. The highest extraction efficiency of antioxidants was observed at 80℃ and 100 bar for 1 h when 90% aqueous methanol solution was used as a cosolvent.
A hydrid-type extraction system, in which ultrasonication was applied to the single-step supercritical fluid extraction, was investigated to improve further the extraction efficiency of antioxidants. The purity of antioxidants in the final extract gradually increased as temperature, amount of cosolvent mixed with SCCO₂ and power of ultrasonication increased. Optimal conditions for the extraction of antioxidants from young barley leaves were found to be 80℃, 150 bar, 2.0 h, 200 mL of cosolvent and 400 W when 100% methanol was used as cosolvent.
The lab-scale single-step extraction apparatus was scaled-up about 10 times, and extraction experiments were performed to obtain engineering data needed for commercialization of the supercritical fluid extraction process.
A double-step supercritical fluid extraction process, which combined organic solvent extraction with a superciritcal aerosol solvent extraction system (ASES) drying process, were developed and its optimal conditions were investigated. The purity of antioxidants in the final extract increased up to 1.3 times, and the purity of pigments decreased up to 74% when methanol was used as extraction solvent and pure SCCO₂ as antisolvent.
An integrated extraction/drying process, which combined sequentially supercritical fluid pre-extraction, solvent-modified SCCO₂ extraction process and supercritical ASES drying process, was developed to improve the purity of antioxidants and to completely remove pigments. Then, the effect of operating parameters on the extraction was investigated in detail. It was found that the purity of antioxidants increased about 1.5 times compared with organic solvent extraction, and pigments were completely removed.
A cosolvent-modified SCCO₂ ASES process was also carried out to dry extract solutions containing a significant amount of water. It was found that this process could be applied to extract solutions containing up to 40%(v/v) of water. The purity of antioxidants in the final extract was improved about 35% and 26% respectively when 80% aqueous MeOH solution and 80% aqueous EtOH solution were used as extraction solvent.
Both residual solvent analysis and cytotoxicity test were conducted to confirm the safety of barley leaves extracts. The residual solvent analysis showed that organic solvents were not detected in the barley leaves extract obtained using the cosolvent-modified SCCO₂ ASES process. Cytotoxicity assay demonstrated that the barley leaves extracts were even less toxic than a surfactant (SDS) widely used in toilet commodity.
To evaluate the stability of barley leaves extracts, the extract was exposed to various environmental stresses for 2 months. The concentration of antioxidants did not change for two months, which confirmed that the barley leaves extract was stable. The stability of cosmetic formulations containing the barley leaves extract was also confirmed through a physical test that estimated the variation in discoloration, pH and viscosity.
To prepare preservative-free cosmetic formulations containing barley leaves extract, an antibacterial test was carried out using a cosmetic formulation with 1,2-hexanediol, which is known to be nontoxic and antibacterial. The preservative-free cosmetic formulations were found to be safe when the concentration of 1,2-hexanediol was higher than 2.0%.
A human patch test were performed for 33 subjects to estimate the skin stimulation level of the preservative-free cosmetic formulations and no skin stimulation was observed for all subjects.