본 연구는 비산소 분쇄 및 포장이 해조류 분말의 색도, 항산화활성 및 미생물 수에 미치는 영향을 조사하였다. 대조구로는 산소 조건하에서 분쇄 및 포장을 진행하였다. 색도는 대조구가 저장기간이 지남에 따라 L값과 b값은 감소하고 a값이 증가하여 갈변현상이 일어나는 것을 확인하였다. 또한, 총 페놀함량 (9.8~8.0mg GAE/100g dw), DPPH (12.57~11.00mg BHAE/100g dw), ABTS (13~8.4mg AAE/100g dw) 및 FRAP (11.2~8.0mg Fe(II)/100g dw)활성이 모두 감소하는 것으로 나타났다. 반면에, 진공-질소치환에 의한 비산소 분쇄 및 포장의 경우 유의적으로 차이가 없는 것으로 나타났다. 미생물수는 대장균군, 일반세균수, 효모 및 곰팡이를 분석하였고 대장균군과 곰팡이는 모든 샘플에서 불검출되었다. 대조구는 0~8주차에서 일반세균수와 효모가 각각 1.52~1.96 log CFU/g, 0~1.77 log CFU/g으로 증가하는 것으로 나타났다. 비산소 분쇄 및 포장 조건은 0~8주차에서 일반세균수와 효모가 각각 1.52~1.53 log CFU/g, 0~1.25 log CFU/g으로 각각 나타나 일반세균수는 유의적으로 차이가 없었으나 효모는 약간 증가한 것으로 나타났다. 따라서, 색도유지, 높은 총 페놀함량 및 항산화 활성 유지, 일반세균 및 효모의 성장 억제를 위해서는 진공-질소치환에 의한 비산소 분쇄 및 포장 조건하에서 품질특성과 미생물수를 유지하는데 효과적일 것으로 판단된다.
본 연구는 다양한 상대습도(11~93%) 조건에서 해조류의 미생물 안정성 및 품질특성에 미치는 영향을 조사하였다. 미생물 안정성은 저장 중 대장균군, 일반세균, 효모 및 곰팡이수를 분석하였다. 일반세균은 상대습도 69~93%에서 4.40~7.00 log CFU/g, 효모 및 곰팡이는 4.20~6.40 log CFU/g로 상대습도 69%이상 조건에서 일반세균, 효모 및 곰팡이의 수가 급격하게 증가하였다. 고결현상은 상대습도 11~53% 조건에서는 일어나지 않았으나 69, 81, 93% 조건에서는 각각 86.9, 99.45, 99.98%로 높은 고결현상을 가지는 것으로 나타났다. 색도는 상대습도가 높아질수록 L값과 b값이 감소하였고, a값이 증가하여 갈변현상이 일어났다. 또한, 총 페놀함량(9.10~8.66 mg GAE/100 g dw), ABTS 소거능(24.20~24.18 mg AAE/100 g dw), FRAP(15.34~15.33 mg Fe(II)/100 g dw)활성은 저장 중 상대습도 11~33%에서 가장 높게 유지되었다. 그러나, 상대습도 43~93%에서 저장 중 총 페놀함량(8.66~4.00 mg GAE/100 g dw), ABTS(22.57~4.50 mg AAE/100 g dw), FRAP(13.06~4.00 mg AAE/100 g dw)활성이 감소하는 것으로 나타났다. 상대습도 81% 조건에서 ABTS 및 FRAP이 1/3배로 감소하였고, 93% 조건에서 총 페놀함량, ABTS 및 FRAP이 각각 1/2배, 1/5배, 1/3배로 감소하였다. 따라서, 일반세균, 효모 및 곰팡이의 성장 억제, 고결현상 방지, 갈변억제, 높은 총 페놀함량과 항산화활성 유지를 위해서는 상대습도 53% 이하의 조건에서 보관하는 것이 미생물 안정성 및 품질특성 유지에 효과적일 것으로 판단된다.
This study investigated the effect of bactocease, as a natural preservative, on the microbial growth and quality of fried fish paste during storage. To select the optimal concentration of bactocease, the inhibition effect of its different treatment concentrations (0.2, 0.4, and 0.8%) on total aerobic bacteria in fish paste dough during 5 days of storage was examined. The sample treated with 0.4% bactocease showed a 1.21 log reduction in microorganisms compared with that of the control. This result was higher than that with 0.2% bactocease and potassium sorbate and similar to that with 0.8% bactocease. Consequently, 0.4% bactocease was chosen as the best concentration for preparing the fried fish paste. Microbial growth on fried samples treated with preservatives was more inhibited by adding preservatives regardless of their type than that of the control after 15 days of storage. In addition, there were no significant differences in the quality between the samples treated with 0.4% bactocease and 0.2% potassium sorbate, such as volatile basic nitrogen contents, TBARS values, pH, and acidity. Therefore, these results indicate that food preservatives should be added into fried fish paste for controlling microbial growth, and bactocease can have a high potential to replace potassium sorbate in processed marine foods, including fried fish paste.
본 연구는 생분해성 용기 개발의 연구성이 대두됨에 따 라서 동물성 재료로 제조한 생분해성 용기의 개발의 목적에 있다. 연구 결과 돈피, 우피, 닭피에 있어서 돈피가 우수한 수율과 단백질 분자량을 가진 것으로 나타났다. 이에 돈피를 이용하여 생분해 용기를 개발하였으며, 단면적 확인 결과 호두 껍질 분말 10%를 첨가한 처리구에서 적은 공극을 보였으며, 호두 껍질 분말 20%를 첨가한 처리구에서 공극의 크기가 큰 것을 확인할 수 있었다. 물성 연구 결과 호두 껍질 분말 10% 처리구가 더 높은 경도를 나타 내었으며, 호두 껍질 분말 20% 처리구가 더 높은 탄력성을 나타내었다. 압축강도는 호두 껍질 분말 20% 처리구가 더 높은 값을 나타내었다. General bacteria, E. coli 연구 결과 모든 일자에서 불검출되어 미생물로부터의 안정성은 더 장기간으로 실험해볼 필요가 있을 것으로 보인다. 또한 높은 항균 능력과 생분해능의 결과를 보여 저장 기간의 안정성이 높은 용기의 개발과 환경의 영향을 최소화 할 수 있을 것으로 판단된다. 따라서 돈피 젤라틴에 난각과 호두 껍질 분말을 넣어 제조한 생분해성 용기의 개발의 기초 데이터로 이용될 수 있을 것으로 생각된다.
This study investigated the microbial community and quality characteristics of traditional soybean pastes (doenjang) based on the aging period in Gyeongnam province. The samples were collected from seven regions in Gyeongnam Province (Goseong, Hadong, Haman, Hamyang, Sacheon, Sancheong and Uiryeong). Contents of moisture, salinity, pH, and acidity of doenjang after 210 days aging were 56.40~65.21%, 9.05~16.08%, 4.88~6.86 and 0.64~2.14%, respectively. Lightness significantly decreased over the aging period, while the redness tended to increase over the aging period. Yellowness was from 21.39~26.81 to 21.10~28.36. Reducing sugar content was from 0.31~1.45% to 0.11~3.13%. The amino-type content increased from 141.87~495.13 mg/100 g to 328.53~823.67 mg/100 g. In contrast, the ammonia-type content declined from 136.74~364.70 mg/ 100 g to 128.62~331.00 mg/100 g. The overall total microbial count did not significantly differ, but it tended to decrease in sample GD4. Fungus declined overall or was not detected. Coliform groups were not detected in all samples. Lactobacillus and Bacillus cereus tended to decrease over the aging period. The common fungus and bacterium were Aspergillus oryzae and Tetragenococcus halophilus, respectively. After the aging period, the predominant fungi were Candida versatilis, Candida apicola, and Debaryomyces hansenii. The predominant bacteria were Tetragenococcus halophilus and Cronobacter sakazakii.
This study was carried out to investigate the changes of the microbiological contamination levels, pH, acidity, solid contents, total phenol contents, and color difference of cold-brew coffee products during 4 weeks at room and cold temperatures. The 17 sample coffees were purchased from regional cafes in Jeonju. Each coffee was self-blended by the cafes. Esherichia coli was not detected in all the samples, but bacteria were detected in 1 sample and yeast and molds were detected in 4 samples. Of the samples stored at room temperature (25oC) after 4 weeks, general bacteria were detected in 4 samples (3.0×101 cfu/ml-1.7×103 cfu/ml), and yeast and molds were detected in 11 samples (1.3×101 cfu/ml - 3.1×105 cfu/ml). In the case of the samples stored at cold temperature (4oC), general bacteria were detected in 3 samples, and yeast and molds were detected in 6 samples although the level of contamination was lower than that at room temperature. pH and acidity decreased during the storage period, but the total phenol content did not change. In the case of chromaticity, redness and yellowness tended to decrease.
The goal of this study was to evaluate effects of various microbial and organic additives on chemical compositions, fermentation indices, and aerobic stability of barley silage. Youngyang barley harvested at 31.5% dry matter (DM), and ensiled into 20 L bucket silo for 0, 1, 3, 7, 48, and 100 d in quadruplicates with four additives following: sterile destilled water at 1% of fresh forage (CON); Lactobacillus plantarum at 1.2 x 105 cfu/g of fresh forage (CL); Lactobacillus buchneri at rate of 1.2 x 105 cfu/g fresh forage (LB); Fermented Persimmon Extract at 1% of fresh forage (FPE); and Essential Oil at 1% of fresh forage (EO). On 100 d of ensiling, CL and FPE silages had lower (p<0.05) DM than CON silage. Additionally, FPE silage had higher (p<0.05) crude protein than CON silage. All silages with additives, except EO, had higher (p<0.05) neutral detergent fiber (NDF) than CON silage. Silage treated with CL, LB, and FPE had lower in vitro DM digestibility than CON silage, and silages treated with LB and FPE had higher in vitro NDF digestibility (IVNDFD) on 100 d of ensiling. The PFE silage produced the highest (p<0.05) lactate during ensiling period, while LB silage produced the highest (p<0.05) acetate. All inoculated silages had higher (p<0.05) LAB count than control silage. Only CL silage had higher (p<0.05) yeast count than control silage, while the other silages were not differ compared to CON silage. The aerobic stability was higher (p<0.05) in LB and FPE silages than in CON silage. In conclusion, FPE could be an alternative additive to increase IVNDFD, fermentation indices, and aerobic stability of barley silage.
This study was carried out to investigate the effect of chlorine water and plasma gas treatment on the quality and microbial control of Latuca indica L. baby Leaf during storage. Latuca indica L. baby leaves were harvested from a plant height of 10cm. They were sterilized with 100μL·L-1 chlorine water and plasma-gas (1, 3, and 6hours), and packaged with 1,300cc·m-2·day-1·atm-1 films and then stored at 8±1?and RH 85±5% for 25days. During storage, the fresh weight loss of all treatments were less than 1.0%, and the carbon dioxide and oxygen concentrations in packages were 6-8% and 16-17%, respectively for all treatments in the final storage day. The concentration of ethylene in the packages fluctuated between 1-3μL·L-1 during the storage and the highest concentration of ethylene was observed at 6 hours plasma treatment in the final storage day. The off-odor of all treatments were almost odorless, the treatments of chlorine water and 1 hour plasma maintained the marketable visual quality until the end of storage. Chlorophyll content and Hue angle value measured at the final storage day were similar to those measured before storage in chlorine water and 1 hour of plasma treatments. E. coli was not detected immediately after sterilization in all sterilization treatments. After 6 hours of plasma treatment, the total bacteria fungus counts were lower than the domestic microbial standard for agricultural product in all sterilization treatments. The total aerobic counts in the end storage day increased compared to before storage, whereas E. coli was not detected in all sterilization treatments. The sterilization effect against bacteria and fungi was the best in chlorine water treatment. Plasma treatment showed sterilization effects, but within a prolonged period of time. In addition, the sterilization effect decreased gradually. These results suggest that chlorine water and plasma treatment were effective in maintaining Latuca indica L. baby Leaf commerciality and controlling microorganisms during postharvest storage.
This study examined the quality characteristics and anti-oral microbial activity of bamboo leaf jelly prepared with different 5 levels (0, 10, 20, 30, and 40%) of bamboo (Phyllostachys nigra var. henonis) leaf extract. The sugar contents of bamboo leaf jelly were increased significantly by increasing the level of bamboo leaf extract. The luminance and Hunter’s a values of the jelly samples increased with increasing bamboo leaf extract, but the 40% bamboo leaf jelly had the lowest Hunter’s b values. The hardness, adhesiveness, gumminess, and chewiness increased significantly with increasing bamboo leaf extract. Among the mechanical properties, only the flavor of the jelly with 30 and 40% bamboo leaf extract were increased significantly. The extract of bamboo leaves had strong antimicrobial activity against S. mutans, S. sobriuns, P. gingivalis, and P. intermedia at a concentration of 40%. These results suggest that bamboo leaf extract can be useful in the production of high quality jelly.
본 실험에서는 냉동 새우(Litopenaeus vannamei)를 4oC에서 12일동안 저온 저장하며, 키토산 코팅과 천연보존제의 병행처리(0.05% carvacrol, 0.05% thymol)가 미생물(중 온균, 저온균, Pseudomonas spp., H2S 생성균)의 성장과 새우의 이화학적 특징(총 휘발성 질소화합물, pH) 및 관능적 품질(외관, 냄새, 전반적 수용도)에 미치는 영향을 살펴보았다. 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 모든 대상 미생물의 성장을 억제하였고 특히 중온균, 저온균, H2S 생성균의 경우 실험 의 마지막 날인 12일째까지 유의적인 항균효과(p < 0.05)를 보였다. 이 처리구들은 총 휘발성 질소화합물과 관능적 특성(외관, 냄새, 전반적 수용도)에서도 12일째까지 유의적인 차이(p < 0.05)를 보였으나 pH에서는 유의적 차이 가 없었다. 따라서 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 새우의 주요 부패 미생 물의 성장을 효과적으로 억제하는 것으로 보이며 냉장 새우의 유통기간 연장에 활용할 수 있을 것으로 보여진다.
The present study analyzes the role of Lactic Acid Bacteria Mixture (LBM) on improving rye silage quality. Rye of four different stages (Booting, Heading, Flowering, and Late flowering) was collected and silage was prepared. The nutrient profile analysis of experimental silage groups showed no significant changes between control and LBM inoculation. Interestingly, the pH of rye silage in LBM treatments showed significant reduction than control (p<0.05) in all stages of rye silage. However, lowest pH (3.69) resulted on booting stage among other stages of rye. Subsequently significant lactic acid production was noted in all stages of LBM inoculation than control. Conversely maximum lactic acid production of (5.33%DM) was noted at booting stage followed by (4.86%DM) in heading stage. Further the lactic acid bacterial (LAB) count in LBM inoculated group showed significant increase than control. Similarly, the silage of booting stage group registered maximum LAB population (63.7 ×106CFU/g) after that heading stage (32.3 ×106CFU/g). Further significant reduction in yeast growth and no fungal growth was noted in all LPM treatment groups. Hence, LBM inoculants could be a better additive for improving rye silage quality.
The effects of high hydrostatic pressure (HHP) or concentration treatment or sodium hydrogen carbonate addition on microbial and quality properties of cold drip liquid coffee were investigated during storage at room temperature. Cold drip liquid coffee was determined to pH, acidity, general bacteria, and Y&M (Yeast and Molds) according to HHP treatment or adding 0.2% sodium hydrogen carbonate for 40 days storage at 20°C. Also, an equivalent mixture of concentrated coffee and cold drip liquid coffee or liquid coffee with 0.2% sodium hydrogen carbonate was used for determining the sensory evaluation, due-trio and preference test. The cold drip liquid coffee with 0.2% sodium hydrogen carbonate had higher pH and lower titratable acidity than the control during 40 days storage at 20°C. Total viable cell and Y&M counts of cold drip liquid coffee added with 0.2% sodium hydrogen carbonate or treated by HHP at 300 MPa for 25 min were lower than the control during storage at 20°C. The result of the due-trio and preference tests shows that there was no significant difference between cold drip liquid coffee added to 0.2% sodium hydrogen carbonate and the control or between the equivalent mixture of concentrated coffee with cold drip liquid coffee and the control. As a results, Cold drip liquid coffee treated by HHP, concentrated by evaporation, and added to sodium hydrogen carbonate has a potential to extend a shelf life at ambient temperature storage.
Electrolyzed water(EW) was used for washing of mungbean sprouts to reduce microorganism counts. The aerobic bacteria and yeasts and mold counts in commercial mungbean sprouts were 7.67 and 7.70 log CFU/g, respectively, indicating that the contamination level of the sprouts was very high. Mungbean sprouts were washed EW produced at varying flow rates of brine and water streams. EW produced with 100 ml/min of brine and 300 ml/min of water showed the best performance in reducing microorganisms without affecting the sensory quality of mungbean sprouts. The EW washing showed no signification negative effects on reducing sugar, total phenolics and DPPH radical scavenging activity of mungbean sprout. For further storage of mungbean sprouts. EW washing was effective for reducing microbial counts during storage.
This study investigated the quality characteristics and biological activities of rice germ fermented by Bacillus spp. During the milling process, the contents of rice germ in the rice bran (Control) were adjusted to 30% (RG30) and 70% (RG70). The approximate composition, pH, total acidity, total soluble solid, total sugar, polyphenol and flavonoid contents were measured. DPPH radical scavenging activity, xanthine oxidase (XO) and angiotensin converting enzyme (ACE) activities were also determined. We observed that the moisture content decreased after fermentation, while the crude protein was significantly increased. Fermentation remarkably lowered the pH from 5.83~6.26 to 4.77~4.93, thereby elevating the total acidity. Fermentation also increased the total solid contents, from 0.40~0.87 °Bx to 1.63~2.20 °Bx. The total sugar decreased to 136.81~151.53 mg/mL from 377.56~450.64 mg/mL. Polyphenol contents were the highest in control (0.59 and 0.73 mg/mL before and after fermentation, respectively). Fermentation significantly affected the increase of the polyphenols in both rice germ 30% and 70% samples, from 0.26 and 0.28 mg GAE/g before fermentation, to 0.52 and 0.70 mg GAE/g after fermentation, respectively. There was a slight increase in the flavonoid contents after fermentation. The IC50 value of the electron donating ability, as evaluated by the DPPH method, was the lowest in control (3.77 and 3.36 mg/mL before and after fermentation, respectively). Fermentation increased the XO inhibition activity up to 63.69% in control, 49.81% in rice germ 30%, and 59.32% in rice germ 70%. The ACE inhibition activities were also increased in the fermented control, rice germ 30% and 70%, to 40.51%, 22.69% and 33.91%, respectively.
본 연구는 오존수 침수처리가 소와 돼지 부산물의 미생물학적 안전성 및 품질특성에 미치는 영향에 대해 알아보고자 실시하였다. 미생물학적 안전성 및 품질평가를 위하여 총균 및 대장균수, 육색, 가열감량, 지방산패도를 측정하였으며, 처리구 설정은 처리하지 않은 대조구(Control)와 일반수돗물(10℃)로30분간 침수처리한 처리구 1(T1), 오존수(1.0ppm, 10℃)에 10분간 침수처리한 처리구 2(T2), 오존수에 20분간 침수처리한 처리구 3(T3) 및 오존수에 30분간 침수처리한 처리구 4(T4)로 분류하였다. 소 및 돼지의 간, 소창의 가열감량은 모든 처리구에서 유의적인 차이가 없었으며(p>0.05), 간보다는 소창에서 높은 가열감량을 보였다. 육색은 소의 간과 소창에서는 오존수 20 또는 30분 침수 처리시 황색도 값을 감소시키나, 명도 및 적색도 값에서 유의적인 차이가 나타나지 않았다(p>0.05). 지방산패도 측정 결과, 돼지 소창의 경우 일반수돗물 및 오존수 침지 처리시 대조구에 비해 낮은 지방산패도 값을 나타내었으며 오존수 침지 처리시 유의적으로 낮게 나타났다(p<0.05). 소 간의 경우 대조구에 비해 모든 처리구에서 유의적으로 높은 지방산패도 값을 보였으며 일반수돗물로 침지한 T1에 비해 오존수 침지시 낮은 지방산패도 값을 나타내었다. 총균 및 대장균수는 저장기간이 증가할수록 모든 처리구에서 유의적으로 증가하며(p<0.05), 대조구 및 T1에 비해 오존수 침지처리구에서 유의적으로 낮은 총균 및 대장균수를 나타내었다(p<0.05). 이상의 결과를 통해 오존수 침지처리는 축육부산물의 품질특성 저하 없이 미생물로부터 안전성 확보가 가능할 것으로 판단된다.