• Membrane Journal
• /
• v.14 no.1
• /
• pp.37-43
• /
• 2004

As the experimental results of membrane application for the production and recovery of volatile fatty acids, suspended solids concentration, the number of acid producing bacteria and organic acid concentration increased with membrane coupling in the fermenter. The application of membrane for the efficiency increase of solid-liquid separation and fermentation made the number of acid producing bacteria increase in the fermenter, thus acid forming rate showed higher value than that of membrane-free fermenter. Membrane-coupled fermenter was believed to be an effective technology for the improvement of recovery efficiency of volatile fatty acids from organic sludge.

• Analytical Science and Technology
• /
• v.16 no.6
• /
• pp.458-465
• /
• 2003

The HS (headspace)-SPME (Solid phase microextraction) as rapid and simple method was performed for the determination of volatile fatty acids (VFAs) from the aqueous samples. In-fiber derivatization of VFAs with 1-Pyrenyldiazomethane (PDAM) was applied to improve their sensitivity of detection. In SPME procedure, typical parameters such as effects of solution pH, and salting out reagent and ultrasonication were investigated to improve the extraction efficiency. Based on the developed method, VFAs in wastewater samples were determined by gas chromatography / mass spectrometry-selected ion monitoring (GC/MS-SIM) mode.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2006.05a
• /
• pp.233-240
• /
• 2006

식육의 독특한 맛 성분과 향기성분의 전구물질은 각각 적육과 지방 조직의 수용성 물질이라고 보고되어 있으며(도변(渡邊) 과 좌등(佐藤), 1974), 가열육의 기호성에 관여하는 향미는 복합적인 전구물질들이 열처리 과정에서 일어나는 여러 가지 반응에 의하여 많은 휘발성 물질들이 생성되면서 얻어지는 것으로 알려져 있다. 식육향에 관여하는 휘발성 성분들은 약 600개 이상이 동정되어 있고, 식육의 종류, 품종, 연령, 성별, 사료 등이 이러한 향기에 영향을 주며, 또한 도살 후 저장되는 동안에 휘발성 성분들의 변화 양상은 가열육의 향기에 절대적인 영향을 주게 된다. 일반적으로 냉장육의 경우는 자기 소화에 의한 숙성 효과로 연도와 풍미가 향상되게 되며 숙성된 육은 비숙성육보다 기호성이 우수하다. 우육의 기호성은 향기, 맛 및 조직감이 상호작용하여 결정되는데 우육에 함유되어 있는 지질 및 지방산 조성은 우육의 맛과 풍미에 많은 영향을 미친다(Waldam 등, 1968). 도변(渡邊) 과 좌등(佐藤)(1974)은 지질이나 유리지방산 등에서 생성되는 화합물들과 지방산의 불포화도, 지방산의 자동 산화 정도 등이 우육 향기에 관여하고 있다고 하였다. 본 연구 결과는 저장온도가 낮을수록 저장성을 증가시킬 수 있다는 김 등(1996)의 보고와 일치하였다.

• Journal of Convergence for Information Technology
• /
• v.10 no.11
• /
• pp.177-184
• /
• 2020

The objective of this study was to investigate the effect of cold-pressed flaxseed oil through the roasting temperature (unroasted and roasted at 150℃ and 200℃) and time (10 and 20 min) on the chemical changes. Cold-pressed flaxseed oil extraction yield was calculated with respect to the roasted process and total phenolic content, fatty acid composition, and volatile compound were analyzed. The extraction yield was increased in the roasted oil compared to the unroasted oil. Total phenolic content was significantly higher in oil from the roasted at 150℃ for 20 min compared to other roasting condition. Fatty acid composition was not affected by the extraction process. The content of aldehyde, ketone, furan, and pyrazine was higher than in the roasted at 200℃ compared to the unroasted and roasted at 150℃. These findings suggest that cold-pressed flaxseed oil extracted from the roasted at 150℃ for 20 min may be considered acceptable for safe extraction process.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2004.10a
• /
• pp.416-420
• /
• 2004

본 연구에서는 현재 우리나라에서 식용으로 많이 쓰이는 식물성 유지인 콩기름, 올리브유, 고추씨기름을 Gas Chromatography를 이용해 각 유지별 지방산의 정성, 정량하였으며 이들 유지의 산화 안정성 평가를 위하여 산화적 반응의 기작의 생성물인 휘발성 분해 산물인 Pentanal 생성을 비교하여 분석하였다. 1. Soybean oil의 지방산 조성은 불포화 지방산은 87.79%, 포화지방산은 12.21%를 차지했으며 Olive oil의 지방산 조성은 불포화 지방산은 82.77%, 포화지방산은 17.23%를 차지했다. Hot pepper oil의 지방산 조성은 불포화 지방산은 85.42%, 포화지방산은 14.58%를 차지했다. 2. 콩기름, 올리브기름, 고추씨기름의 pentane의 함량은 43.4, 30.4, 19.7nL로 측정되었다. 따라서 고추씨기름이 다른 유지에 비해 산화에 대하여 안정함을 알 수 있다. 이상의 결과로부터 실험에 선택된 콩기름, 올리브유, 고추씨기름에는 포화 지방산보다 불포화 지방산의 함량이 많은 것을 알 수 있었고, 특히 체내에서 합성이 불가능해 식품으로 섭취해야만 하는 필수 지방산의 함량이 높아 체내 생체 활동에 유용한 것으로 판단되었다. 산패도 비교 평가에서는 hot pepper seed oil이 olive oil이나 soybean oil보다 낮은 산패도를 나타내어 다른 유지보다 산화 안정성이 뛰어난 것으로 나타났다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.3
• /
• pp.312-320
• /
• 1996

This study was to investigate the changes of phytotoxicity of food waste during composting at an aerated static pile for 80 days. The concentration of sodium in the final compost increased by more than 30% and almost of the sodium was a water soluble type which corresponds to about 94% of the total concentration. Major volatile fatty acid(VFA) produced during the composting was acetic acid and also somewhat of butyric acid. High concentration of acetic acid during the composting was kept up for a month and then decreased progressively. It suggests that the phytotoxicity by the VFAs produced during composting of food waste could be removed through a stabilization process in a period of about 40 days. From the statistical analysis between germination index(G.I.) and VFAs. or G.I. and sodium, the phytotoxicity of food waste samples was more dependent in the changes of acetic acid concentration than that of sodium concentration. Considering low G.I. value in the final food waste compost which is matured completely, however. the agricultural utilization of the food waste compost may be to have a big problem due to excess sodium of the compost which is impossible to remove by composting and seriously inhibits growth of plants.

• Journal of the Korean Chemical Society
• /
• v.31 no.3
• /
• pp.244-249
• /
• 1987

Liquid-solid extraction technique was applied to enrich volatile free acids (VFAs) from aqueous matrices. Chromosorb P was found to be an efficient solid sorbent. The unionized VFAs could be quantitatively recovered from the Chromosorb P column with ether while interfering watermiscible components were retained in the adsorbed water on the surface of Chromosorb P. The method of simple and efficient isolation-enrichment of VFAs, followed by the quantitative analysis employing stainless steel capillary column coated with Carbowax 20M containing phosphoric acid has been applied to the determination of VFAs in several aqueous samples.

• Analytical Science and Technology
• /
• v.26 no.6
• /
• pp.364-374
• /
• 2013

The major ten odorous compounds have been analyzed from four swine facilities in Jeju Island, in order to investigate the emission characteristics and odor contribution by different ventilation systems and manure treating types. From the study, the concentrations of $NH_3$ and TMA were high at the enclosed ventilation and scraper type facilities in winter season, and the sulfur compounds ($H_2S$, $CH_3SH$, DMS, DMDS) as well as volatile fatty acids (PA, n-BA, n-VA, iso-VA) showed high concentrations at the enclosed ventilation type facilities during winter season. The concentrations of nitrogen and sulfur compounds were high at slurry manure treat facilities. However, the volatile fatty acids (VFA) were relatively high in the scraper type swine facilities. The odor quotients of n-BA were high at four swine facilities, therefore the volatile fatty might be considered as the major odor causing compounds. Moreover the sum of odor quotient (SOQ) was high at the enclosed ventilation and scraper type facilities, and the odor contributions by volatile fatty acids were high in all swine facilities.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.14 no.1
• /
• pp.61-66
• /
• 1985

Cooked rice was prepared by the conventional cooking method being used among Korean families. The bottom layer (very slightly roasted and charred) and upper layer of the cooked rice in a cooking vessel were collected separately in order to determine the chemical changes and volatile carbonyl formation occurring in rice during the cooking process. Amino acids, especially free amino acid contents were reduced with the decrease of reducing sugar in rice after cooking. A little change was shown in the fatty acid composition of lipid fractions, however, decreased iodine values and increased fatty acid values were observed after cooking process. Volatile carbonyl compounds from cooked rice were isolated and 8 carbonyls of them were identified. A significant difference of relative composition of the identified carbonyls was found between the upper layer and bottom layer of cooked rice. Generally, the cooked rice obtained from the bottom layer had shown a little more changes in chemical composition and a stronger browning flavour than those of the upper layer of cooked rice.

• Food Science of Animal Resources
• /
• v.23 no.1
• /
• pp.1-8
• /
• 2003

The purpose of this study was to investigate the effects of the sausage containing mulberry leaf(0.04%, 0.08%) and persimmon leaf powder(0.04%, 0.08%) on lipid oxidation(Thiobarbituric Acid Reactive Substances, TBARS), nitrite, volatile basic nitrogen(VBN) and fatty acid composition. The TBARS values of sausage containing mulberry leaf and persimmon leaf powder were not significantly different(p > 0.05) as compared to control during 45 days of storage, but TBARS values of sausage containing 0.04% mulberry leaf and persimmon leaf powder were significantly lower than those of control at 60 days of storage. The nitrite scavenging ability of sausage containing mulberry leaf and persimmon leaf powder was higher than that of control. The VBN content of all treatments significantly increased(p < 0.05) during the storage periods. In fatty acid compositions, the percentages of PUFA/SFA of sausage containing mulberry leaf and persimmon leaf powder were significantly higher as compared to control. In conclusion, sausage containing mulberry leaf and persimmon leaf powder was a more effective natural resource on the basis of the lipid oxidation and nitrite scavenging ability of sausage.