본 연구에서는 풋사과에서 폴리페놀 성분을 효율적으로 추출하고 분리하였으며, 분리된 폴리페놀 성분을 미세캡슐화 하여 그 특성을 조사함으로써 기능성 폴리페놀 소재로의 활용성을 제고하였다.
색도와 항산화 성분 함량을 통해 설정된 풋사과 전처리 방법으로 100℃에서 3분간 blanching 처리를 하였다. 총 페놀 함량을 통해 Viscozyme L 효소 처리 조건을 기질에 대한 효소 농도 2%(v/w), 반응시간 12시간으로 설정하여 풋사과로부터 폴리페놀을 추출하였다. 이 때 총 페놀 함량은 354.01 mg%였고, 이는 효소를 처리하지 않은 대조군(224.93 mg%)에 비해 1.6배 높은 값을 나타냈다.
풋사과 폴리페놀을 분리하여 폴리페놀 함량을 증진시키기 위해 풋사과 효소 추출물을 Diaion HP-20 gel column chromatography를 이용하여 water, 25%, 50%, 75%, 100% ethanol로 용출하였다. 각 획분의 총 페놀 함량과 총 플라보노이드 함량으로 항산화성분을, DPPH 및 ABTS 라디칼 소거 활성, FRAP활성으로 항산화 활성을 조사한 결과 50% ethanol 획분에서 가장 높은 항산화 성분 함량과 항산화 활성을 보였다(p<0.05). 항균 활성 또한 50% ethanol 획분에서 가장 컸다(p<0.05). 이를 통해 50% ethanol 획분에서 항산화 및 항균 활성을 나타내는 폴리페놀의 분리가 이루어진 것으로 사료된다. 풋사과에서 분리된 폴리페놀 성분을 확인하고자 TLC를 실시한 결과, 25% ethanol 획분에서 chlorogenic acid, caffeic acid와 phloridzin을 50% ethanol 획분에서 caffeic acid와 phloridzin을 확인할 수 있었다. 각 획분의 폴리페놀 성분을 HPLC를 이용해 확인한 결과, 50% ethanol 획분에서 가장 폴리페놀 성분 함량이 높았으며, 각각의 폴리페놀 성분 함량은 caffeic acid는 387.88 μg/mL, p-coumaric acid는 226.34 μg/mL, phloridzin의 함량은 187.33 μg/mL로 나타났다.
항산화 및 항균 활성이 좋은 풋사과 폴리페놀의 50% ethanol 획분에 피복물질로 dextrin과 chitooligosaccharide를 가하여 분무건조 함으로써 microcapsule dextrin(microcapsule A)과 microcapsule chitooligosaccharide(microcapsule B)를 제조하였다. 수분함량을 측정한 결과, Microcapsule A가 2.25%, Microcapsule B가 3.60%였다. 평균 입도는 Microcapsule A가 36.89 μm, Microcapsule B가 33.34 μm였으며, Michrocapsule B가 Microcapsule A보다 입도가 고르게 분포되어 있었다. 겉보기 밀도는 Microcapsule A와 Microcapsule B가 각각 0.31 g/mL, 0.36 g/mL였고, 다짐 밀도는 0.51 g/mL, 0.61 g/mL로 겉보기 밀도와 다짐 밀도 모두 Microcapsule B가 높았다. 하지만 압축성에서는 유의적인 차이를 보이지 않았다. 용해도는 30℃와 60℃에서 모두 90% 이상으로 매우 높았으며, Microcapsule A가 Microcapsule B에 비해 더 큰 용해도와 팽윤력을 보였다. 열 안정성은 온도가 증가할수록 색도의 변화가 컸으며, Microcapsule B에서 차이가 컸다. 갈변도는 Microcapsule A는 50℃와 100℃에서 변화를 보였으며, Microcapsule B는 75℃에서 변화가 나타났다. pH 안정성은 pH 변화가 클수록 색도의 변화가 컸으며, Microcapsule A에서 보다 큰 차이를 보였다. 갈변도 또한 pH 변화가 클수록 차이가 컸으며 pH 1에서 큰 변화를 보였다. 흡습성은 Microcapsule B가 Microcapsule A에 비하여 컸다. 이와 같이 항산화성이 증진된 풋사과 폴리페놀 추출물의 미세캡슐은 정제, 스틱, 캡슐제 등의 형태로 가공 될 수 있으며, 기능성 소재로의 다양한 활용이 가능할 것으로 기대된다.

In this study, the process for efficient extraction, isolation polyphenol compounds and microcapsulation of unripe apples were developed and the properties of microencapsules of unripe apple polyphenols were investigated.
The pretreatment of unripe apples was blanched at 100 ℃ for 3 min determined by Hunter color’s value and antioxidant contents. Polyphenols were extracted from unripe apples by the enzymatic extraction. The proper extract conditions were that the conentration of Viscozyme L to substrate was 2%(v/w), and reaction time was 12 hours. Total phenol content of enzyme extract was 354.01 mg%, which was 1.6 times higher than that of the control without enzyme treatment (224.93 mg%).
To increase the polyphenol contents, the extracts of unripe apples were eluted with water, 25%, 50%, 75% and 100% ethanol by Diaion HP-20 gel column chromatography. Each fraction was investigated for antioxidant contents with total phenolic contents and total flavonoid contents, for antioxidant activities with DPPH, ABTS radical scavenging activities and FRAP activities. 50% ethanol fraction were the highest in antioxidant contents and activities(p<0.05). The antimicrobial activity was also highest in 50% ethanol fraction(p<0.05). As these results suggest that the polyphenols which have antioxidant and antimicrobial activities were isolated at 50% ethanol fraction. As a result of TLC for analysis of the polyphenol compounds isolated from unripe apple, chlorogenic acid, caffeic acid and phloridzin were identified in 25% ethanol fraction, and caffeic acid and phloridzin in the 50% ethanol fraction. The polyphenol compounds of each fraction were analysed by HPLC. 50% ethanol fraction were the highest in the polyphenol contents and it has 387.88 μg/mL of caffeic acid, 226.34 μg/mL of p-coumaric acid, and 187.33 μg/mL of phloridzin.
The 50% ethanol fraction, which was rich in polyphenols were added to dextrin and chitooligosaccharide as excipients and spray dried to microcapsulation. Unripe apple microcapsule with dextrin was named by microcapsule A and unripe apple microcapsule with chitooligosaccharide was named by microcapsule B. Moisture contents of Microcapsule A and Microcapsule B were 2.25% and 3.60%, respectively. The particle size of Microcapsule A was 36.98 μm, Microcapsule B was 32.98 μm, and Michrocapsule B was evenly distributed than Microcapsule A. The bulk density and tapped density of Microcapsule B were higher than Microcapsule A. However, there was not significant difference in compressibility. The solubilities were high over than 90% at 30 ℃ and 60 ℃. Microcapsule A showed higher solubility and swelling power than Microcapsule B. The temperature stability of the microcapsules was that the color values of the microcapsules increase as the temperature increase. The browning intensities of Microcapsule A was changed at 50℃ and 100℃, and Microcapsule B was changed at 75℃. The pH stability of the microcapsules was that the color values and browning intensities of the microcapsules change as the pH change and showed a large change at pH 1. Water uptake of Microcapsule B was higher than that of Microcapsule A. Microcapsules of unripe apple polyphenols can be processed into tablets, sticks, capsules ect, and it is expected to be variously used as a functional material in the food industry.