The Biochemical Studies on Stored Soy-sauce

저장(貯藏)간장의 생화학적(生化學的) 연구(硏究)

Studies were carried out in order to elucidate chemical components and microflora in three types of soy-sauce, 12-year aged soy-sauce prepared by improved method. 7-year aged and 20-year aged soy-sauce prepared by ordinary method. They results are summarized as follows: 1. The followings are found to be the important factors affecting the quality of soy sauce. a. Organic acids, reducing sugars and free amino acids were increased in the course of storage. b. In the aged soy-sauces under study non-volatile organic acid increased while volatile organic acid decreased and the total acidity was dependent only upon tie latter. c. It was found that suit concentration decreased during the storage. 2. The results of investigation of microflora in the stored soy-sauce are shown as follows. Soy-sauce Improved Ordinary Microbe 12-Y. 20-Y. 7-Y. Aerobic bacteria colony/1ml. 6 123 2 Halophilic lactic acid bacteria colony/1ml. 4 6 10 Osmophilic yeast colony/1ml. $828{\times}10^4$ 248 - b. In the stored soy-sauces, aerobic bacteria are incapable of growing due to drop in pH value and the influence of salt concentration. c. Halophilic lactic acid bacteria are incapable of growing due to drop in pH value, even the salt concentrations decreased during the storage. d. Osmophilic yeast are still growing in low pH value and in the decreasing salt concentration during the strage. 3. The results of amino acid analysis by paper partition chromatographic and calorimetric methods are shown as follows. a. Fourteen kinds of amino acid and thirteen amino acids were detected in the soy-sauce of 12-year aged improved soy-sauce and 7-year aged and 20-year aged ordinary one, respectively. b. The contents of aspartic acid, glutamic acid, serine, valine, leucine, lysine, histidine and methionine increased in the 20-year aged ordinary soy-sauce compared to the 7-year aged one. On the other hand those of alanine, tyrosine, phenylalanine and cystine decreased. 4. The results of sugar analysis by paper chromatography are as follows. a. In the 12-year aged improved soy-sauce, galactose, glucose, arabinose, xylose, rhamnose, maltose and an unknown were detected, and their amounts were in the above order except maltose and an unknown. b. Both in the 7 and 12-year aged ordinary soy-sauces, galactose, arabinose, xylose, glucose and rhamnose were detected and the amounts of the sugars were in the above order. c. In the non-aged ordinary soy-sauce, glucose was not detected but detected from 7-year and 20-year aged ordinary soy-sauce. 5. The results of organic acid analysis by paper chromatography were as follows. a. As volatile acids, acetic, propionic and butyric acids were detected in the 7-year aged ordinary soy-sauce. On the other hand in both the 20-year aged ordinary soy-sauce and the 12-year aged improved ones, only acetic acid was abundant while propionic and butyric acids were round in trace. It was found that propionic and butyric acids, as the unpleasant flavor components, decreased during the storage. b. In the ordinary soy-sauce, citric acid were produced during the storage and lack, malic and tartaric acids increased in the course of aging while succinic, glycolic, fumaric and malonic acids were shown to decrease. Glutaric and oxalic acids disappeared. Citric acid was produced also in the improved soy-sauce, but lactic, tartaric, succinic, malic, and glycolic acids decreased, while both malonic and glutaric acids disappeared. From the above results the citric acid production was considered to be a favorable factor for the taste. c. In the aged soy-sauces, pyruvic, α-ketoglutaric and probably acetoacetic and oxaloacetic acids (both in trace) were present and their amounts were in the above order. All of the α-keto acid abruptly decreased during the storage.

12년(年) 묵은 개량식(改良式) 간장과, 20년(年) 묵은 재래식(在來式) 간장 및 7년(年)묵은 재래식(在來式) 간장에 대(對)하여 화학적(化學的) 조성(組成)을 분석(分析)하고 microflora를 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. 1. 간장 맛에 영향을 주는 일반성분(一般成分)의 분석결과(分析結果)는 다음과 같았다. a) 오래 묵은 간장일수록 재래식(在來式) 및 개량식(改良式) 간장을 불문(不問)하고 맛을 좌우(左右)하는 성분(成分)인 유기산(有機酸), 유리환원당(遊離還元糖) 및 유리(遊離) 아미노산(酸)의 함량(含量)이 증가(增加)되었다. b) 유기산(有機酸)에 있어서 오래 묵은 간장일수록 비휘발성(非揮發性) 유기산(有機酸)은 증가(增加)하고 휘발성(揮發性) 유기산(有機酸)은 감소(減少)하며, 총산(總酸)은 비휘발성(非揮發性) 유기산(有機酸)에 의(依)하여 지배(支配)되어 있음을 알았다. c) 식염농도(食鹽濃度)는 오래 묵은 간장일수록 감소(減少)되었다. 2. 저장(貯藏)간장중(中)의 microflora를 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. a) 일반세균(一般細菌)은 묵은 간장중(中)에서 pH의 강하(降下) 및 식염농도(食鹽濃度)의 영향(影響)으로 생존(生存) 불능(不能) 상태(狀態)였다. b) 내염성(耐鹽性) 유산균(乳酸菌)은 저장(貯藏)함에 따라 식염농도(食鹽濃度)는 강하(降下)하기는 하나 pH의 강하(降下)로 거의 생존(生存)이 불능상태(不能(狀態)였다. c) 내염성효모(耐鹽性酵母)는 묵힐수록 어느 시기 이후는 식염농도(食鹽濃度)의 강하(降下) 및 pH 직강하(直降下)로 생존(生存)됨을 알았다. 3. Paper chromatography 및 colorimetry에 의(依)하여 유리(遊離) 아미노산(酸)을 분석(分析)한 결과(結果)는 다음과 같았다. a) 재래식(在來式) 간장에 있어서 7년(年)묵은 간장에 대하여 20년(年) 묵은 간장중에는 aspartic acid, glutamic acid, serine, valine, leucine, lysine, histidine, methionine이 증가(增加)하였고, alanine, tyrosine phenylalanine, cystine이 감소(減少)하였다. b) 개량식(改良式) 간장에 있어서는 colorimetry로 정량(定量)된 산(酸)의 양적(量的)인 변화(變化)는 햇간장에 대하여 12년(年)된 간장중의 methionine, tyrosine, histidine는 감소(減少)하고, phenylalanine는 증가(增加)하며 cystine는 별차(別差) 없었다. 4. Paper chromatography에 의하여 유리당류(遊離糖類)를 분석(分析)한 결과(結果)는 다음과 같았다. a) 12년(年)묵은 개량식(改良式) 간장중(中)에서 galactose, glucose, arabinose, xylose, rhamnose, maltose, unknown 1를 검출(檢出)하였고, 정량(定量)한 당류(糖類)의 함량(含量)은 maltose와 미지당(未知糖)을 제외(除外)하고 이상(以上)의 순위(順位)와 같았다. b) 20년(年), 7년(年) 묵은 재래식(在來式) 간장에서 galactose, arabinose, xylose, glucose, rhamnose를 다같이 분리(分離)하였으며 그들의 함량(含量)은 이상(以上)의 순위(順位)와 같았다. c) 7년(年) 및 20년(年) 묵은 재래식(在來式) 간장중(中)에서 햇간장중(中)에 별로 없든 glucose가 생성(生成)되었다. 5. Paper chromatograhpy에 의하여 유기산(有機酸)을 분석(分析)한 결과(結果)는 다음과 같았다. a) Volatile acid i) 7년(年) 묵은 재래식(在來式) 간장중(中)에서 acetic acid, propionic acid, butyric acid를 분리(分離)하였으며, acetic acid가 제일 많았다. ii) 20년(年)된 재래식(在來式) 간장과, 12년(年)된 개량식(改良式) 간장중(中)에는 acetic acid가 주로 많았고, propionic acid, butyric acid는 흔적 정도(程度)로 분리(分離)되었다. iii) 간장은 오래 묵힐수록 고린냄새의 한성분(成分)인 propionic acid, butyric acid가 격감(激減)함을 알았다. b) Non-volatile acid i) 재래식(在來式) 간장에 있어서는 묵힘에 따라 생성(生成)된 것은 citric acid이고, 증가(增加)된 것은 lactic, malic, tartaric acid이고 감소(減少)된 것은 succinic, glycolic, fumaric, malonic acid이며 소실(消失)된 것은 glutaric, oxalic acid이다. ii) 개량식(改良式) 간장에 있어서는 묵을수록 생성(生成)된 것은 citric acid이고, 증가(增加)된 것이 latic, tartaric acid이며, succinic, malic, glycolic acid는 감소(減少)하였고 malonic, glutaric acid는 소실(消失)되었다. iii) 묵은 간장중(中)의 citric acid의 생성(生成)은 간장 맛을 좋게하는 인자(因子)가 될 것으로 생각된다. c) ${\alpha}-Keto$ acid i) 모든 묵은 간장중(中)에서 pyruvic, ${\alpha}-ketoglutaric$, acetoacetic(추정(推定)), oxaloacetic(추정(推定)) acid를 분리(分離)하였으며 양적(量的)인 순위(順位)는 pyruvic acid, ${\alpha}-ketoglutaric$ acid이고, 기타는 흔적 정도(程度)였다. ii) 모든 ${\alpha}-Keto$ acid는 간장이 묵을수록 격감(激減)함을 알았다.