S-methylmethionine(vitamin U)은 천연 아미노산의 일종으로 Brassica vegetables 중 양배추에 풍부하게 함유된 항위궤양성 인자로 알려져 있다. 본 연구에서는 우리나라에서 많이 소비되고 있는 배추를 대상으로, 건조방법을 달리하여 품종 및 부위별로 vitamin U 함량 변화를 조사하였다. 건조방법에 따른 함량변화는 동결건조 처리군이 vitamin U 최대 보존 효과를 보여주었다. 부위별로는 전체적으로 잎 부분(leaf parts)이 줄기(mid-rib)보다 최소 1.1배, 최고 21.2배 높았으며 그중에서 배추 잎 바깥쪽(outward parts)에서 가장 높은 vitamin U 함량을 나타내었다. 주요 아미노산의 함량은 vitamin U와 같이 잎 부분이 전반적으로 높았으며, 특히 alanine과 threonine이 가장 풍부한 아미노산으로 조상되었다. Vitamin U의 전구물질인 methionine의 함량은 건조방법에 따라 큰 차이를 보여주었으나, vitamin U 함량에 미치는 영향은 뚜렷한 상관관계를 보이지 않았다

S-methylmethionine, vitamin U levels were affected by cultivars, parts of Korean Chinese cabbages, and drying methods. Among drying conditions, freeze drying method appeared the best condition to maintain vitamin U content compared to oven and air drying methods. In the case of Korean Chinese cabbages, outward leaves have high levels of chlorophyll and fiber. From this study, the outward parts contained high levels of vitamin U in two cultivals. Leaf parts were 1.1-21.2 times higher in vitamin U levels than midribs in both cultivars. This difference was shown most distinctively in freeze dried outward parts of Winter Pride cultivar. Like vitamin U, free amino acids also showed much higher levels in leaves. Levels of amino acids showed irregularly changing patterns at different parts and cultivars of Korean Chinese cabbages with various drying methods. Alanine and threonine appeared relatively abundant amino acids in most parts of samples. Since no distinctive trends were observed in this result, it seems no relationship exits between amino acids and vitamin U levels. Levels of methionine in different parts and cultivars of Korean Chinese cabbages dried with various methods did not show clear relationship with the level of vitamin U. Moreover, methionine was not detected in freeze dried outward leaf parts which were the highest parts of vitamin U levels in Winter Pride 55 days cultivars. There were similar levels of methionine between oven and freeze drying. Sample prepared by air drying showed significantly lower levels than those by oven and freeze drying. Methionine as a precursor of vitamin U, may not play a role in an in crease of vitamin U during drying of Korean Chinese cabbgages.

• Kim, Gun-Hee