• 한국식생활문화학회지
• /
• 제10권1호
• /
• pp.11-17
• /
• 1995

전통안동식혜를 제조하여 $5^{\circ}C$에서 보관하면서 GC와 GC-MS를 이용하여 향기성분의 원인 물질을 분석, 동정하였고 맛성분의 원인물질인 유기산의 변화를 검토하였다. 안동식혜의 주요 향기성분으로는 camphene, sabinene, 1-(1.5-dimethyl-4-hexyl)-4-methyl-benzene, ${\alpha}-zingibirene$, farnesene, 2.6-b is-(1.1-dimethylethyl)-4-methyl-phenol, ${\beta}-sesquiphellandrene$, calalene, tetradecanoic acid, hexadecanoic acid 및 9.12-octadecanoic acid 등을 들 수 있었다. 안동식혜의 숙성 및 저장중에 있어서 생성된 향기성분은 2.4-undecadienal, 1H-indole, 2.4-decadienal, isoterpinolene 및 D-nerdiol 5종류이었다. 비휘발성 유기산 함량의 변화를 보면 저장 초기에는 젖산 0.49 mg/100 g이던 것이 19.37 mg/100 g으로 증가하였고 다른 유기산들의 함량 변화는 거의 없었다. 안동식혜의 숙성 및 저장 기간중의 pH의 변화는 차차 감소하였고 산도는 차차 증가하여 저장 6일째 0.41이었다.

• 한국식품영양과학회지
• /
• 제42권5호
• /
• pp.721-729
• /
• 2013

본 연구는 염농도의 저하에 따른 저염 오징어젓갈의 유통기한 감소에 대하여 유통기한의 연장과 기능성 제품화의 가능성을 검토하기 위하여 천연식물추출물 첨가에 따른 저장기간별 품질특성, 최적발효기한, 유통기한 설정 및 생리활성을 연구하였으며, 그 결과는 다음과 같다. 첨가군 모두 저장온도가 증가할수록 pH는 급격히 감소하였고, 아미노질소, 휘발성염기질소의 함량은 급격히 증가하였으며, 총균수 역시 증가하였다. 유통기한 및 최적발효기한은 Arrhenius equation의 결과에 따라 $10^{\circ}C$에서 대조구 34 및 28일, 월계수첨가 35 및 29일, 녹차첨가 34 및 30일, 솔잎첨가 34 및 29일 저장한 것이었다. 구성 및 유리아미노산은 첨가군 모두가 glutamic acid, glycine, alanine 등의 감칠맛, 단맛을 내는 아미노산의 함량이 대부분을 차지하여 맛에서 우수하다고 판단되었고, 핵산관련물질은 첨가군 모두 쓴맛을 나타내는 hypoxanthine이 대부분을 차지하였으며, 그 뒤 inosine 및 정미성분인 IMP 순이었다. 관능검사결과 월계수첨가군이 종합적으로 가장 뛰어났다. 생리활성은 첨가군이 대조구에 비해 활성이 높았으며, 기능성 제품으로서의 상업화가 가능하다고 판단된다. 그러므로 천연식물추출물을 첨가한 저염 오징어젓갈은 웰빙 등 시대의 변화에 맞추어 현대인의 식기호에 적합한 식품으로 이용 가능하며, 젓갈의 고급화 및 부가가치 창출이 가능하다고 사료된다.

• Journal of Animal Science and Technology
• /
• 제60권11호
• /
• pp.27.1-27.8
• /
• 2018

Background: Enteric methane ($CH_4$) accounts for about 70% of total $CH_4$ emissions from the ruminant animals. Researchers are exploring ways to mitigate enteric $CH_4$ emissions from ruminants. Recently, nano zinc oxide (nZnO) has shown potential in reducing $CH_4$ and hydrogen sulfide ($H_2S$) production from the liquid manure under anaerobic storage conditions. Four different levels of nZnO and two types of feed were mixed with rumen fluid to investigate the efficacy of nZnO in mitigating gaseous production. Methods: All experiments with four replicates were conducted in batches in 250 mL glass bottles paired with the ANKOM$^{RF}$ wireless gas production monitoring system. Gas production was monitored continuously for 72 h at a constant temperature of $39{\pm}1^{\circ}C$ in a water bath. Headspace gas samples were collected using gas-tight syringes from the Tedlar bags connected to the glass bottles and analyzed for greenhouse gases ($CH_4$ and carbon dioxide-$CO_2$) and $H_2S$ concentrations. $CH_4$ and $CO_2$ gas concentrations were analyzed using an SRI-8610 Gas Chromatograph and $H_2S$ concentrations were measured using a Jerome 631X meter. At the same time, substrate (i.e. mixed rumen fluid+ NP treatment+ feed composite) samples were collected from the glass bottles at the beginning and at the end of an experiment for bacterial counts, and volatile fatty acids (VFAs) analysis. Results: Compared to the control treatment the $H_2S$ and GHGs concentration reduction after 72 h of the tested nZnO levels varied between 4.89 to 53.65%. Additionally, 0.47 to 22.21% microbial population reduction was observed from the applied nZnO treatments. Application of nZnO at a rate of $1000{\mu}g\;g^{-1}$ have exhibited the highest amount of concentration reductions for all three gases and microbial population. Conclusion: Results suggest that both 500 and $1000{\mu}g\;g^{-1}$ nZnO application levels have the potential to reduce GHG and $H_2S$ concentrations.

• Asian-Australasian Journal of Animal Sciences
• /
• 제32권1호
• /
• pp.63-71
• /
• 2019

Objective: The aim of the study was to investigate the effect of zinc-bearing palygorskite (Zn-Pal) on rumen fermentation by in vitro gas-production system. Methods: In trial, 90 incubators were evenly divided into five groups: control (0% Zn-Pal), treatment I (0.2% Zn-Pal), treatment II (0.4% Zn-Pal), treatment III (0.6% Zn-Pal), and treatment IV (0.8% Zn-Pal). The contents of zinc for treatments were 0, 49, 98, 147, 196 mg/kg, respectively. The main chemical composition and microstructure of Zn-Pal was investigated by X-ray diffraction. The physicochemical features were evaluated by Zeta potential analysis, cation-exchange capacity, ethylene blue absorption and specific surface area (the Brunauer-Emmett-Teller method). In vitro gas production (GP) was recorded at 3, 6, 9, 12, 18, 24, 36, 48, 60, and 72 h incubation. Incubation was stopped at 0, 6, 12, 24, 48, and 72 h and the inoculants were tested for pH, microbial protein yield (MCP), $NH_3-N$, volatile fatty acids (VFAs), lipopolysaccharide (LPS). Results: The results showed that the GP in the treatment groups was not significantly different from the control groups (p>0.05). Compared to the control group, pH was higher at 24 h, 48 h (p<0.05), and 72 h (p<0.01) (range 6 to 7). The concentration of $NH_3-N$ in the three treatment groups was higher than in the control group at 24 h (p<0.01), meanwhile, it was lower at 48 h and 72 h (p<0.01), except in the treatment IV. The concentration of MCP in treatment I group was higher than in the control at 48 h (p<0.01). Compared with control, the LPS concentration in treatment III became lower at 12 h (p<0.05). Total VFAs in treatments were higher than in the control at 24 h, 48 h (p<0.05). Conclusion: These results suggest that the addition of Zn-Pal can improve the rumen fermentation, especially when adding 0.2% Zn-Pal.

• Asian-Australasian Journal of Animal Sciences
• /
• 제32권4호
• /
• pp.533-540
• /
• 2019

Objective: This study evaluated the growth, digestibility and rumen fermentation between goats and sheep fed a fattening diet fortified with linseed oil. Methods: Twelve 3 to 4 months old male goats and sheep were randomly allocated into two dietary treatment groups in a $2(species){\times}2$ (oil levels) factorial experiment. The treatments were: i) goats fed basal diet, ii) goats fed oil-supplemented diet, iii) sheep fed basal diet, and iv) sheep fed oil-supplemented diet. Each treatment group consisted of six animals. Animals in the basal diet group were fed with 30% alfalfa hay and 70% concentrates at a rate equivalent to 4% of their body weight. For the oil treatment group, linseed oil was added at 4% level (w:w) to the concentrate portion of the basal diet. Growth performance of the animals was determined fortnightly. Digestibility study was conducted during the final week of the feeding trial before the animals were slaughtered to obtain rumen fluid for rumen fermentation characteristics study. Results: Sheep had higher (p<0.01) average daily weight gain (ADG) and better feed conversion ratio (FCR) than goats. Oil supplementation did not affect rumen fermentation in both species and improved ADG by about 29% and FCR by about 18% in both goats and sheep. The above enhancement is consistent with the higher dry matter and energy digestibility (p<0.05), as well as organic matter and neutral detergent fiber digestibility (p<0.01) in animals fed oil- supplemented diet. Sheep had higher total volatile fatty acid production and acetic acid proportion compared to goat. Conclusion: The findings of this study suggested that sheep performed better than goats when fed a fattening diet and oil supplementation at the inclusion rate of 4% provides a viable option to significantly enhance growth performance and FCR in fattening sheep and goats.

• 한국산학기술학회논문지
• /
• 제19권12호
• /
• pp.814-824
• /
• 2018

거세한우 3두를 $3{\times}3$ Latin square design 시험방법에 적용하여 사료 적응 기간 10일 후 사료 급여 방식에 따른 반추위액 내 휘발성지방산과 단당류 비교 분석 및 대사산물 분석에 대한 연구를 수행하였다. 연구 결과 HPLC와 HPAEC에서 측정되지 않은 휘발성지방산과 단당류들은 $^1H-NMR$에서는 측정이 가능 한 것을 알 수 있었다. $^1H-NMR$에서 측정된 대사산물 중, carbohydrate 계열 대사산물 pyruvate는 사료 급여 전 반추위액에서만 측정 되었으며, succinate는 사료 급여 전 후에서 모두 측정 되었다. Amino acid 계열 대사산물은 총 9가지가 측정 되었다. Lipid 계열 대사산물 ethylene glycol는 사료 급여 전 Con구에서 유의적(P<0.05)으로 높게 측정 되었다. Aiphatic acylic compounds 계열 대사산물 trimethylamine N-oxide는 유의적인 차이는 보이지 않았다. 이번 연구를 통해 $^1H-NMR$를 이용하여 반추위액 내 많은 대사산물 측정이 가능한 것을 알 수 있었으며 사료 급여 전 후 급여 방식에 따라 대사산물의 변화가 나타나는 것을 확인 할 수 있었다.

• Animal Bioscience
• /
• 제34권9호
• /
• pp.1466-1478
• /
• 2021

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

• 한국식품저장유통학회지
• /
• 제30권2호
• /
• pp.287-299
• /
• 2023

효소 및 미생물 복합제를 사용하여 인비트로 발효 루왁커피를 제조하여 non-fermented coffee beans(NFC)과 fermented coffee beans(FC)의 커피 품질을 비교하였다. 총유리아미노산 함량은 NFC가 254.01±4.89 mg/mL, FC가 264.15±16.80 mg/mL로 FC의 함량이 다소 높은 것으로 확인되었다. 이때 NFC는 glutamic acid, γ-aminon-butyric acid 등이 높았으나, FC는 lysine, leucine, valine 등 필수아미노산의 함량이 높았다. 커피 생두의 발효과정은 sucrose의 감소와 fructose 및 glucose의 유의적인 증가를 가져왔다. 커피 추출물의 색도는 NFC에 비해 FC 시료에서 높은 명도(L)와 적색도(a) 및 황색도(b)를 보였다. 카페인 함량은 NFC 1,130.22±1.55 ㎍/mL, FC 696.94±0.04 ㎍/mL로써 발효 후 약 38%의 카페인이 감소되었다. 폴리페놀 및 클로로겐산 함량은 NFC에서 각각 2.31±0.01 mg GAE/mL와 531.81±27.32 ㎍/mL, FC에서 각각 2.03±0.07 mg GAE/mL와 264.46±2.47 ㎍/mL로 발효에 따라 떫은맛 관련 성분의 함량이 유의적으로 감소됨을 알 수 있었다. 전자코 분석에서 NFC와 FC의 휘발성 향성분의 차이가 뚜렷함이 확인되었고, methylethyl formate, 2-methyl-1, 3-cyclopentadiene, 2-chloro-2-methylbutane, 2-methylbutanal 등의 휘발성 화합물이 발효 후 높은 강도로 감지되었다. 관능 평가에서는 NFC 추출물보다 FC 추출물의 aroma, body, aftertaste, overall에서 높은 관능 평점을 보여주었다(p<0.001). 이상의 결과에서 효소 및 미생물 복합제를 사용한 커피 생두의 발효는 유효 성분들의 변화를 일으켜 커피 원두의 로스팅 과정 중 Maillard 반응을 촉진함으로써, 향미가 증가되고 카페인 함량이 감소된 인비트로 루왁 커피의 제조 가능성을 시사하였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권1호
• /
• pp.82-89
• /
• 2009

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

• 한국식품과학회지
• /
• 제28권4호
• /
• pp.762-771
• /
• 1996

무의 품종과 계절별로 깍두기의 품질 중 향미 특성이 일정하게 유지되는지 알아 보고자 깍두기의 향미 성분 분석 및 관능 검사를 수행하였으며 또, 향미 특성치들 간의 품종별 계절별 차이와 상관관계 및 관능 검사의 전체적인 수용도에 영향을 미치는 특성치들을 알아 보았다. 소형무 깍두기는 대형무 깍두기에 비해 숙성 전 기간동안 pH는 약간 높았고 산도는 약간 낮게 유지되었다. 계절별 깍두기의 pH는 봄, 여름, 가을의 순으로 각각 평균 3.85, 3.99, 4.46이었다. 총산도의 증가 경향은 전 품종 모두 봄 및 여름무에 비해 가을무의 증가 정도가 컸으며, 소형무보다 대형무의 총산도 증가가 컸다. 계절별로 깍두기 숙성기간동안의 평균 환원당 함량은 가을무 깍두기의 환원당 함량이 가장 높았다. 비휘발성 유기산의 함량은 숙성됨에 따라 lactic acid는 현저히 증가되었고 succinic acid와 fumaric acid는 발효 중반기까지는 증가되다가 그 이후 다시 감소되었으며 malic acid는 숙성이 진행됨에 따라 계속 감소되는 경향을 나타내었다. SDE추출물을 GC/MS로 분석하여 밝혀진 isothiocyanate들은 4-methylthiobutyl, 5-methylthio-pentyl, 4-methylsulfinyl-3-butenyl isothiocyanate 등이었다. 관능검사 결과, 소형무로 담근 깍두기의 전체적인 수용도 점수는 대형무 깍두기보다 높은 점수를 나타내었다(p<0.05). 대형무 깍두기는 향미 특성치들이 계절별로 차이가 있었다. 소형무와 대형무 품종 간에 유의적 차이를 나타내는 깍두기의 특성치들은 lactic acid 함량, 매운맛, 단맛이었다. 계절별로 소형무 품종 간에 또한 소형무 품종별로 계절 간에 환원당 함량과 단맛은 상호 영향이 존재하였다. 품종 및 계절별로 전체적인 수용도 점수가 높은 품종은 동자무이었으며 가을 동자무 깍두기의 전체적인 수용도와 양의 상관관계를 나타내는 특성치는 무김치 냄새와 신냄새이었고 산도, lactic acid 함량, 단맛 및 매운맛과는 음의 상관을 나타내었다. 전체적인 수용도 점수에 영향을 주는 향미 특성치들을 다중 회귀분석한 결과, 봄 동자무 깍두기는 overall acceptability =-0.ll15 + 1.2519 savory taste + 1.5159 malic acid -0.0054 total isothiocyanates + ${\varepsilon}$의 식으로 표시할 수 있었다.