The release of aroma compounds in different pectin gel systems under static and dynamic headspace conditions

Abstract

17가지의 휘발성 향기성분의 서로 다른 펙틴 젤 [low methoxyl pectin (LMP)과 amidated low methoxyl pectin (LMAP), PME (Pectin methylesterase)에 의해 LMP와 LMAP가 변형된 very low methoxyl pectin (각각, VLMP와 VLMAP)]에서의 방출 정도를 static과 dynamic headspace를 이용해서 분석하였다. Static condition에서 사용된 17가지의 휘발성 향기성분은 2 alcohols (1-butanol, 1-hexanol), 3 ketones (2,3-butanedione, 2-butanone, 2-octanone), 2 aldehydes [(E)-2-hexenal, heptanal], 3 sulfur-containing compounds (dimethyl disulfide, 2-propene-1-thiol, 1-propanethiol), 그리고 7 esters (ethyl acetate, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl propionate, propyl propionate, and butyl propionate) 계열 화합물들이었다. 모든 향기성분들은 저장기간 7일 동안의 partition coefficients가 유의적으로 변화하였는데, 일반적으로 황 함유 화합물의 partition coefficients가 가장 크고, esters, aldehydes, ketones, 그리고 alcohols의 순서로 방출되는 정도가 감소하였다. 펙틴 젤의 종류 별로 살펴보면, VLMAP 젤에서의 방출정도가 가장 높았고 LMP, LMAP 그리고 VLMP의 순서로 방출되는 정도가 감소하였다. 그리고 각 펙틴 젤에서 칼슘별로 방출정도를 비교를 해 보았을 때, 2-butanone, ethyl acetate, 그리고 1-propanethiol을 제외한 모든 휘발성 향기성분들은 칼슘에 의한 차이가 유의적으로 나타나지 않았다. Dynamic condition는 model mouth를 이용하여 VLMP와 LMP 젤에서의 휘발성 향기성분의 방출을 살펴보았는데, 이 때 총 11가지 휘발성 향기성분[1-hexanol, 2-octanone, (E)-2-hexenal, heptanal, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl propionate, propyl propionate, butyl propionate, 그리고 dimethyl disulfide]을 사용하였다. 두 가지의 펙틴 젤에서의 향기성분 방출을 살펴본 결과, 칼슘 농도가 90 mg/g pectin일 때 대부분의 향기성분 LMP 젤에서의 방출이 VLMP 젤보다 유의적으로 많았다. 그러나 heptanal과 ethyl octanoate는 VLMP 젤에서의 방출이 더 높았는데, 이는 이 두 향기성분들이 다른 성분에 비해 비극성이기 때문에 좀 더 비극성인 LMP에 결합되어있기 때문으로 보인다. 두 펙틴 젤에서의 esters의 향기성분의 방출을 살펴보면, C8로 esters의 탄소 수가 증가함에 따라서 향기성분의 방출은 증가하다가 C10에서는 감소하였다. 그리고 VLMP에 세 가지 수준의 칼슘 첨가하였을 때에는 aldehyde를 제외한 대부분의 휘발성 향기성분들의 방출이 칼슘의 농도가 증가함에 따라 감소하는 경향을 보였다.;The release of 17 aroma compounds in different pectin gel systems, containing low methoxyl pectin (LMP), amidated low methoxyl pectin (LMAP) and PME (Pectin methylesterase)-modified pectins [very low methoxyl pectin (VLMP) and very low methoxyl pectin with amidation (VLMAP) from LMP and LMAP], respectively, was analyzed under static and dynamic headspace conditions. The 17 aroma compounds were 2 alcohols (1-butanol, 1-hexanol), 3 ketones (2,3-butanedione, 2-butanone, 2-octanone), 2 aldehydes [(E)-2-hexenal, heptanal], 3 sulfur-containing compounds (dimethyl disulfide, 2-propene-1-thiol, 1-propanethiol), and 7 esters (ethyl acetate, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl propionate, propyl propionate, and butyl propionate). Most of the aroma compounds showed significantly decreased the release during 7 days storage. In general, sulfur-containing compounds indicated the highest release, followed by esters, aldehydes, ketones, and alcohols. In addition, the release of the 17 aroma compounds was highest in VLMAP gel, followed by in LMP, LMAP, and VLMP gels, regardless of calcium contents. The release of most aroma compounds, except 2-butanone, ethyl acetate, and 1-propanethiol, was not significantly sensitive to calcium content. On the other hand, the release of 11 aroma compounds, such as 1-hexanol, 2-octanone, (E)-2-hexenal, heptanal, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl propionate, propyl propionate, butyl propionate, and dimethyl disulfide, was measured under dynamic headspace condition for VLMP and LMP gels using a model mouth system. The release of most aroma compounds was significantly higher in LMP gel than in VLMP gel (p<0.05). However, the release of heptanal and ethyl octanoate, which are relatively non-polar, was higher in VLMP gel than in LMP gel at calcium content of 90 mg/g pectin. When the release of a series of esters with different carbon numbers as compared, it increased to C8 and then decreased to C10 in both LMP and VLMP gels. When more calcium was added to VLMP, the release of most aroma compounds, except for aldehyde, was significantly reduced (p<0.05).