김치의 숙성과정 중의 물리적 특성을 측정하기 위하여 원료배추의 엽두께, 절임시의 두께 및 pH, total acidity, 염도 등의 변화를 연구하였다. 원료배추의 엽두께는 최외엽보다 내엽의 두께가 50% 감소되었고 절임의 경우에서는 외엽이 내엽보다 감소율이 낮았다. 배추조직의 절단력 측정에서는 절임으로 인하여 상대적인 절단력이 높았고 김치숙성이 되면서 증가하며 7일을 기준으로 감소하였다. Stress에서도 상대적 절단력과 같은 경향이나 숙성 후의 감소되는 점이 잘 나타나지 않았다. pH의 변화에 대한 상관식은 Y=0.23X+6.13이었고 젖산함량의 관계식은 Y=0.09X-0.01로서 매우 완만한 기울기이었으며 김치로서의 적정수준은 pH4.2, 젖산함량은 0.63의 수준이었고 기간은 7일이었다.

첨가 부재료를 달리한 김치를 18℃에서 24시간 예비 발효시킨 후, 4℃에서 35일간 저장하면서 질산염, 아질산염 및 vitamin C의 함량변화를 살펴보았다. 염도가 2.5% 수준인 김치 숙성도를 pH와 산도로 판정해 볼 때, 초기 숙성속도는 새우젓〉멸치, 갓, 마늘〉대조구, 무우〉ascorbic acid〉K-sorbate 순이었고 35일 후 pH 기준으로, 그 숙성도는 대조구〉갓〉무우〉ascorbic acid, 멸치젓〉새우젓〉K-sorbate〉마늘 첨가구 순이었다. 총 vitamin C 함량은 적숙기인 2주에 ascorbic acid 첨가구를 제외한 시료들에서 18.2-26.4 mg%로 담금직후와 같은 수준이었다. 그 중 환원형 ascorbic acid 보존율은 마늘, 갓, K-sorbate 첨가구에서 비교적 좋았다. 질산염, 아질산염의 함량은 숙성초기에 마늘, 무우첨가 김치에서 비교적 높았으며, 숙성기간 중 질산염의 함량범위는 260-490ppm이었고, 숙성 3주째에 최소량을 나타내었으며 이때 아질산염은 검출되지 않았다. 그리고, 총 vitamin C 함량도 이때 가장 낮았다.

A consumer survey(2, 251 residents) on marketed kimchi products in Seoul and near Seoul Area were investigated for marketablity and quality improvement of kimchi. The results obtained as follow. 1. The proportion of subjects who has bought the marketed kimchi products was 24%, some factors(ages, type of housing, family system, income) were investigated. 2. The major motivation season and favorite kinds of kimchi for purchasing the products were investigated. And Subjects bought the needed amount for 1 day at hygienic store. 3. Subjects prefered the taste of kimchi which is medium level in sour, sweet, salty and hot. The most urgent improvement for the marketed kimchi is the sanitation. If marketed kimchi were improved over the aspects, the proportion of subjects who would buy the products was 54%.

김치발효 중 일어나는 조직감의 변화에 영향을 미치는 요소들을 규명하기 위하여 조직경화제로서 CaCl2, 숙성지연제로서 K-sorbate, 숙성촉진제로서 새우젓 및 멸치젓의 첨가효과와 이들 시료의 데침효과를 조사하였다. pH와 산도 및 환원당의 변화양상을 보면 새우젓 및 멸치젓 첨가구가 숙성촉진 효과를, K-sorbate, CaCl2, 데침처리 등이 숙성지연효과를 뚜렷이 나타내었다. K-sorbate, CaCl2 및 데침처리에 의하여 발효중 김치배추의 절단강도 감소속도가 지연되었으며 압착력, 회복높이, work ratio의 감소속도도 지연되었으나 젓갈첨가는 이를 촉진시켰다. 이러한 결과는 관능검사에서 젓갈첨가구가 굳은 정도, 아삭아삭한 정도, 질긴 정도, 뻣뻣한 정도가 크게 낮아지는 반면, 보존료 첨가나 데침으로 이들 값이 증가하는 것과 일치하였다. pH, 산도, 배추잎의 절단두께, 절단력, 압착력, 회복높이, work ratio 등 기계적 측정치들은 신맛, 조직감, 외관의 기호도와 굳은 정도, 아삭한 정도, 질긴 정도, 뻣뻣한 정도 등의 조직감 특성과 높은 상관관계를 나타내었다. 특히, 김치의 pH는 김치의 신맛, 외관, 질긴 정도, 굳은 정도, 뻣뻣한 정도, 아삭아삭한 정도와 높은 상관관계를 나타내었다.

김치의 표준화를 위한 기초자료로서 1976년부터 1987년까지 간행된 김치관계자료 896건을 수집하여 종류와 사용하는 재료들을 검토한 결과 김치류 및 절임류의 명칭은 총 186종에 달하고 그중 김치류 106종, 깍두기류 16종, 동치미류 10종, 소박이 11종, 겉절이 및 생채류 18종, 장아찌 23종, 기타 식해류 2종이었다. 사용하는 재료는 총 118종에 달하고, 주재료별로는 무우가 34%, 배추가 14%, 기타 채소가 30%를 차지하고 동물성 재료와 해조류가 15%를 차지하고 있다. 통배추김치, 보쌈김치, 백김치 등 배추를 주원료로 하는 김치의 재료는 배추, 소금, 마늘, 고추, 생강, 파, 미나리 등을 사용하고 그밖에 젓갈류, 갓, 깨, 굴 등 30종 이상의 재료를 사용하는데 비하여 무우를 주재료로 하는 깍두기, 동치미 등은 무우, 소금, 고추, 마늘, 파, 생강 등을 주재료로 하는 것은 배추김치류와 같지만 부재료의 종류가 20종으로 훨씬 단순하였다. 그밖에 열무김치, 오이소박이 등에 사용되는 재료도 검토하였다.

우리나라 김치 종류에 대한 문헌적 고찰들을 종합하고 지난 200년 사이에 일어난 김치제조기술의 변화를 조사하였다. 또한 최근의 과학적 방법에 의한 김치 연구결과 중에서 김치의 품질에 영향을 미치는 요소들, 특히 맛, 영양, 안전성, 저장성에 관한 재검토를 시도하였다.

To suggest the development possibility of immunostimulating materials from lactic acid bacteria (LAB) postbiotics, Lactobacillus sakei/Leuconostoc mesenteroides were isolated from Kimchi. Next, two isolated LAB were cultured to prepare postbiotics (LABP) to measure macrophage activity. LABP significantly increased the production of macrophage stimulating factors such as nitric oxide, tumor necrosis factor-α, and interleukin-6. LABP-crude polysaccharides (CP) fractionated from LABP by EtOH precipitation not only showed more potent macrophage stimulating activity but also induced phagocytic activity in a dose-dependent manner. In addition, LABP-CP was identified as polysaccharides with a major monosaccharide composition of mannose (59.1%), glucose (23.0%), and galactose (14.0%) with high-molecular-weight of 103.5~126.7 kDa. In conclusion, postbiotics prepared from LAB isolated from Kimchi were confirmed to have industrial applications as a functional material with immunostimulating activity.

Dental caries is an infectious disease that is caused by the interaction between the host, the diet, and a diverse microbial community. This study illustrated the anticariogenic effects of THYJ-15 against Streptococcus mutans, a major agent of dental caries. THYJ-15 was identified as Latilactobacillus sakei subsp. sakei through 16S rRNA sequencing, with a similarity of 99.72% to L. sakei subsp. sakei JCM 1157T. The cell-free supernatant of L. sakei subsp. sakei THYJ-15 observed MIC values of 10 mg/mL and MBC values of 20 mg/mL against S. mutans KACC 16833T. The cell-free supernatant of L. sakei subsp. sakei THYJ-15 showed significant inhibitory effects on biofilm formation, acid production and glucosyltransferases(GTFs) production against S. mutans. As a results, it was confirmed that L. sakei subsp. sakei THYJ-15 is a lactic acid bacterium possessing notable anticariogenic effects. Accordingly, L. sakei subsp. sakei THYJ-15 is expected to have great potential to be used as a basic substance for dental caries treatment caused by S. mutans.

Dental caries is an infectious disease accompanied by the destruction of teeth. It is a multifactorial disease caused by the interaction between microbes in dental plaque and food, with cariogenic Streptococcus mutans being one of the primary causes. In this study, the antimicrobial and antibiofilm activities of Lactiplantibacillus plantarum THK-j112 isolated from Kimchi, a traditional fermented food, against S. mutans were investigated. Furthermore, this paper also showed the possibility of developing this strain. After analyzing the 16S rRNA sequence, strain THK-j112 was named L. plantarum THK-j112 as it shared 99.93% similarity with L. plantarum ATCC 14917T. Both L. plantarum THK-j112 and L. plantarum ATCC 14917T demonstrated MIC values of 5 mg/mL and MBC values of 10 mg/mL against S. mutans KACC 16833T. The study confirmed that L. plantarum THK-j112 exhibited significant concentration-dependent inhibitory effects on biofilm formation, acid production, and glucosyltransferases(GTFs) production. Regarding hemolytic activity, Bacillus cereus ATCC 14579T, used as a positive control, was confirmed to cause hemolysis, whereas L. plantarum THK-j112 did not cause this phenomenon. Additionally, except for gentamicin, the antibiotic resistance test revealed a lower value than the MIC cut-off value for each antibiotic, indicating no resistance. Based on the findings, L. plantarum THK-j112 is expected to be useful in the food industry, such as functional food, as a lactic acid bacterium with antimicrobial and antibiofilm effects.

The aim of this study was to evaluate the probiotic properties of lactic acid bacteria (LAB) isolated from kimchi and antioxidant and anti-inflammatory activities of heat-killed LAB strains. Regarding probiotic properties, Lactiplantibacillus plantarum SMF398 and L. plantarum SMF470 isolated from kimchi can survive under artificial gastric condition and adhere strongly to HT-29 cells. The SMF398 and SMF470 strains showed strong antimicrobial activity and co-aggregation against pathogenic bacteria. The heat-killed cells of LAB (1 mg/mL) were prepared by heating at 121℃ for 15 min. MTT assay revealed that the heat-killed cells (1 mg/mL) of SMF398 and SMF470 were not toxic to HT-29 cells. The heat-killed SMF398 and SMF470 showed significantly higher DPPH and ABTS radical scavenging activities as well as β- carotene bleaching inhibitory activity than the heat-killed L. plantarum ATCC14917, a control probiotic strain (p<0.05). In lipopolysaccharide-induced RAW264.7 cells, the heat-killed SMF398 and SMF470 significantly reduced the nitric oxide production by 30.92% and 22.81%, respectively (p<0.05). Furthermore, the heat-killed SMF398 and SMF470 significantly decreased the gene expression levels of tumor necrosis factor-α, interleukin-6, inducible nitric oxide synthase, cyclooxygenase-2 up to 58.02%, 67.70%, 53.44%, 45.90%, respectively (p<0.05). These results suggest that the heat-killed L. plantarum SMF398 and L. plantarum SMF470 might be useful as antioxidant and anti-inflammatory agents.

In this study, probiotic properties such as acid resistance, bile tolerance, intestinal adhesion and fat accumulation inhibition of lactic acid bacteria isolated from kimchi were investigated in order to develop probiotics effective anti-adipogenic effects. Among the 120 types of lactic acid bacteria isolated from kimchi, 42 types of lactic acid bacteria being to acid resistance, 35 types of lactic acid bacteria being to bile resistance, and 24 types of lactic acid bacteria being to both acid resistance and bile resistance were selected. These 24 types were tested for the intestinal adhesion ability which is an essential factor of probiotics’ function and L. rhamnosus GG was used as a positive control in this test. 10 types of lactic acid bacteria having the intestinal adhesion ability were selected. The selected 10 types of lactic acid bacteria were treated in 3T3-L1 cells and intracellular fat was stained with Oil Red O reagent to measure fat accumulation. As a result, in the group treated with lactic acid bacteria OS-15, 48, 102 and 120, fat accumulation was significantly decreased compared with the non-treated group. And the strain OS-48 showed the greatest inhibitory effect on fat accumulation. The lactic acid bacterium OS-48 was identified as Lactiplantibacillus plantarum by analysis based on 16S rRNA sequencing and was named Lactiplantibacillus plantarum OS-48. Therefore, based on the results of this study, L. plantarum OS-48 is expected to be very useful as probiotics with anti-obesity effect in the food industry such as fermented food and functional food.

김치로부터 내산성, 내담즙성 및 항산화활성이 우수한 유산균을 분 리하였으며, 프로바이오틱스 활성이 우수한 2종의 균주를 스타터 로 선정하여 고농도의 홍삼 추출물이 보강된 요구르트를 제조하고, 그 품질특성을 평가하였다. 가정에서 제조된 배추김치로부터 분리 한 L. plantarum SY46과 L. brevis SY65 균주는 인공위액과 담 즙염에 대한 저항성, 병원균에 대한 항균활성 및 항산화활성이 상 업용 프로바이오틱스 균주인 L. rhamnosus GG(LGG)와 비교하 여 우수하였으며, auto-aggregation과 co-aggregation 능력은 유사한 특성을 나타내었다. 홍삼 추출분말 5%와 10%가 각각 첨가 된 우유에 SY46과 SY65의 복합 균주를 접종하고 24시간 발효한 결과, 홍삼 요구르트의 pH는 각각 4.46과 4.28, 산도는 1.25%와1.53%, 유산균 생균수는 9.26와 9.90 Log CFU/mL를 나타내었다. 홍삼의 첨가량이 증가할수록 DPPH 라디칼 소거능과 β-carotene bleaching 억제능이 증가되어, 유산균체의 항산화능과 더불어 홍 삼이 요구르트의 항산화능을 높이는데 기여하는 것으로 나타났다. 따라서 본 연구결과, L. plantarum SY46과 L. brevis SY65 균주 를 스타터로 활용하여 프로바이오틱스 및 홍삼의 기능성이 강화된 요구르트의 제조가 가능할 것으로 기대된다.

본 연구의 목적은 L. lactis 와 Leu. citreum 균주를 혼합 배양할 수 있는 배지 조성을 개발하여 이를 통해 김치의 발효 속도 조절을 통한 숙성도 맞춤형 김치를 제조하는 것이다. 먼저 김치 육수의 재 료인 북어, 양파, 무, 다시마, 건고추, 건새우, 대파, 건표고 등을 혼합 또는 단일로 하여 육수를 제조한 후, 이들이 L. lactis 증식에 미치는 영향을 알아본 결과, 건새우를 제외한 모든 재료가 증식을 억제하는 결과를 나타내었다. 질소원, 탄소원 및 성장 촉진 인자로 서 tryptone, peptone, yeast extract, lactose, ascorbic acid 등을 이용하였고 pH 완충제로는 potassium citrate를 사용하였 다. L. lactis가 잘 생장하는 M17배지와 균 생장 및 항균활성을 비 교 평가하여 최종적으로 배지 조성은 건새우 육수에 yeast extract 3%, ascorbic acid 0.05%, potassium citrate 1%, lactose 3% 로 하였다(식용 액체배지1). 개발된 식용 액체배지 1에 L. lactis 에 의해 생장 및 증식에 저해를 받지 않고 만니톨 생성능이 우수한 Leu. citreum을 혼합 배양하고자 glucose, maltose, fructose, sucrose 등 여러 가지 탄소원을 달리하여 Leu. citreum의 생육정 도를 살펴본 결과, 0.1-1%의 농도로 maltose 또는 fructose를 첨 가했을 때 선택적으로 잘 증식하였다. 이어서 발효 조절을 통한 숙 성도 맞춤형 김치를 제조하기 위하여 식용배지 1에다 maltose를 0%, 0.1%, 0.2%, 0.3%의 농도로 달리 첨가한 식용배지 2를 제조 하였다. 여기에 L. lactis 와 Leu. citreum을 혼합 배양한 후 김치 에 첨가하여 10℃에서 5일간 발효시킨 결과, 각 김치별로 pH 5.3, pH 4.9, pH 4.7, pH 4.5를 나타내어 각기 숙성도가 다른 특징을 보여주었다. 결론적으로 본 연구에서 개발한 식용 액체 배지를 사 용하여 L. lactis를 배양한 후 그 배양액을 김치에 첨가함으로써 종 균의 활성 및 생장을 극대화시킬 수 있었다. 또한 액체 배지 조성의 조절을 통해 Leu. citreum 균주와의 혼합 배양이 가능하였고, 이를 이용하여 김치 발효 속도 조절을 통한 숙성도 맞춤형 김치를 제조 할 수 있었다.

To develop Gamma-aminobutyric acid(GABA)-producing probiotics we isolated GABA-producing lactic acid bacteria from kimchi. 17 strains of GABA-producing lactic acid bacteria were isolated among 703 lactic acid bacteria originated from 21 kind of kimchi. Two strains, K991 and K998, were selected with highest GABA production ability. The results of 16S rRNA gene sequence analysis, K991 and K998 were identified as Lactococcus lactis, which showed 99.93% and 99.87% similarity, respectively. When the two strains were cultivated in MRS containing 5% MSG at 30°C, GABA began to be produced after 12 hours, reaching maximum production at 40 hours(13.20 mM and 13.35 mM, respectively). In contrast, GABA production was about three times lower when MSG was not added.

According to the previous study, Lactobacillus pentosus A67 and L. plantarum subsp. plantarum C2 were isolated and screened. In this study, culture broths of strains A67 and C2 were performed various physiological activity assays including antimicrobial, antioxidant, cytotoxicity, cell proliferation activity. The remarkable anti-microbial activities using the culture broths of the two strains were showed by disc diffusion method, MIC tests. In the 2,2-diphenyl-1-picryl hydrazyl (DPPH) and superoxide dismutase (SOD) assays to verify antioxidant activity, culture broths of strains A67 and C2 significantly scavenged free radical maximum by 91.33% and 81.95% respectively compared with arbutin. Also, they showed equivalent activity same as 297.22 units and 255.56 units of SOD respectively. In RAW264.7 cells, culture broths of strain A67 and C2 showed no cytotoxicity. Moreover, they showed significant cell proliferative effects by 173.5% and 143.5% compared to control group respectively. Overall, this study showed that the culture broths of strain A67 and C2 had antimicrobial and antioxidant activities, which could synergically increase the physiological activities. And they had no cytotoxicity and cell proliferative effects. Therefore, it is expected that L. pentosus A67 and L. plantarum C2 could be applied to a wide variety of functional materials including food and medicine as new probiotics.

Lactobacillus pentosus A67 and L. planarum subsp. plantarum C2 was tested the probiotics characterization such as acid, bile acid and antibiotics resistance. Isolates were isolated from the traditional Korean food, collected from traditional markets and homes in Seoul and Gyeonggi Province, and were selected the isolates A67 and C2, which were the most antibacterial to E. coli. According to the analysis of 16S rRNA base sequences, the results showed that L. pentosus ATCC 8041 (similarity 100%), and L. plantarum subsp. plantarum ATCC 14917 (similarity 100%). L. pentosus A67 showed a survival rate of about 98.35% and the L. plantarum C2 showed a survival rate of about 95.62% at pH 2.5, respectively. L. pentosus A67 showed a survival rate of about 94.56% and the L. plantarum C2 showed a survival rate of about 88.81% on the 0.3% bile salt, respectively. L. pentosus A67 and L. plantarum C2 were survived by antibiotics such as the quinolone, aminoglycoside, macrolide, glycopeptide, tetracycline, cephalosporin and phenicillin families. On basis of these results, L. pentosus A67 and L. plantarum C2 are the candidates for useful probiotics.

The quality characteistics and kimchi processing ability of the kimchi cabbage cultivar ‘Cheonjincheongmayup’ (CC) were analyzed and compared with those of the ‘Chunkwang’ (CK) cultivar. The head weight of CC was lower than that of CK, and the head length of CC was larger than that of CK. CC had narrower and longer mid ribs than CK. Furthermore, the head formation index of CC was lower than that of CK. The firmness and soluble solid content were higher in CC than in CK. The salinity of Cheonjincheongmayup kimchi (CCK) was 2.89-3.02%, which was higher than 1.94-2.10% salinity measured in Chunkwang kimchi (CKK). The initial titratable acidity in CCK was higher than that of CKK, but increasd more slowly during storage. CCK was firmer than CKK; lactic acid bacteria in CCK was lower than in CKK initially, but increased more in CKK than in CCK after six weeks of storage. We found that CC was suitable for making Makkimchi because of its long and narrow mid ribs, saltiness, and slow fermentation. CC should be improved as less hot spicy and less hard texture to use a Makkimchi material.