Extractive Nitrogenous Constituents and Their Monthly Variation of Fresh Laver Porphyra dentata

잇바디돌김의 함질소 엑스성분조성 및 월별변동

In order to investigate the composition and monthly variation of extractive nitrogenous components in the laver Porphyra dentata cultured at the south coast of Korea, the fresh laver was analyzed separately for the amounts of free amino acids, combined amino acids, ATP and its related compounds, and quaternary ammonium basis in fresh laver were measured. The extractive nitrogen contents of fresh laver extracts were 760~870 mg/100g (dry basis). Twenty-seven to thirty-one kinds of free amino acids were detected in the laver extracts and their total amounts were 2,404~3,966 mg/100g (on dry basis). The laver extracts showed rich in free amino acids such as alanine, taurine, glutamic acid, glutamine and aspartic acid. Sixteen to twenty-three kinds of combined amino acids were detected in the extracts and their total amounts were 1,429~2,692 mg/100g (on dry basis). Proline, glutamic acid, glycine, phosphoserine, serine were the amin combined amino acids in the extracts. The amounts of ATP and related compounds were 73.3~94.4 mg/100 g (2.04~4.43 $\mu$mol/g, on dry basis). Homarine and trigonelline were detected in all specimens but $\beta$-alaninebetaine, ${\gamma}$-butyrobetaine were found in some. Small amounts of trimethylamine were detected in all samples. Free and combined amino acids were occupying almost 90% of extractive nitrogen. Most of free and combined amino acids showed a marked monthly variation with a maximum in January and March, and a minimum in February and April. The fresh laver P. dentata did not differ much from the fresh laver P. yezoensis in qualitative com-position of extractive components, but their contents were generally low level.

한국 남해안에서 양식생산되고 있는 김류의 함질소엑스성분 조성 및 월별 변동을 구명하기 위하여 1998년 1월부터 4월까지 월별로 전남 장흥군에서 양식된 잇바디돌김, Porphyra dentata 생엽을 매월 1회씩 채취하여 맛과 밀접한 관계가 있는 함질소엑스성분 즉, 엑스분질소, 유리아미노산, 결합아미노산, ATP관련화합물, 4급암모늄염기 등을 분석하여 방사무늬김, P. yezoensis와 비교하였다. 엑스분질소함량은 760~872 mg/100 g(건물)이었다. 유리아미노산은 27~31종이 분석되었으며, 그 총량은 2,404~3,966 mg/100 g(건물)이었다. 함량이 많은 유리아미노산으로서는 alanine, taurine, glutamine, glutamic acid, aspartic acid 등이었다. 결합아미노산은 가수분해 후 16~23종에서 증가하였으며, 유리아미노산 총량의 36.0~112.0% 수준이었다. ATP관련화합물 총량은 73.3~94.4 mg/100 g(2.04~4.43 $\mu$mol/g, 건물)이었다. Be-taine류로서는 homarine과 trigonelline이 모든 시료에서 검출되었고, $\beta$-alaninebetain과 ${\gamma}$-butyrobetaine은 일부시료에서 검출되었다. TMA는 모든 시료에서 확인되었으며, TMAO는 일부시료에서 분리되었다. 잇바디돌김 생엽의 함질소엑스성분 특징은 방사무늬김에서 처럼 유리아미노산과 결합아미노산 함량이 풍부하여 질소분포의 약 90%에 달하는 중요한 맛성분이었으나 그 성분조성의 월별 변동에는 다소 차이를 보여 대부분의 성분들이 1, 3월에 높고 2, 4월에 낮았다. 잇바디돌김은 방사무늬김에 비해 전반적으로 함질소엑스성분 함량이 약간 낮은 수준이었다.