Effects of Organic Acids on In Vitro Ruminal Fermentation Characteristics and Methane Emission

Ji Un Ok(옥지운),Dong Uk Ha(하동욱),Shin Ja Lee(이신자),Eun Tae Kim(김언태),Sang Suk Lee(이상석),Young Kyun Oh(오영균),Kyoung Hoon Kim(김경훈),Sung Sill Lee(이성실) 한국생명과학회 2012 생명과학회지 Vol.22 No.10

본 연구의 목적은 organic acids를 첨가하여 in vitro 상의 반추위 발효성상과 반추위 내 메탄 억제에 미치는 영향에 대한 효과를 알아보고자 하였다. 반추위액은 순천대학교 부속목장의 반추위 cannula가 시술된 Holstein에서 채취하였고, organic acids는 반추위액과 버퍼의 혼합액에 첨가하여 배양하였다. 그 결과 pH 값은 lactic acid, malic acid 및 succinic acid첨가구에서 6.69에서 6.16 정도로, 대조구와 다른 첨가구보다 낮았다. 총 가스 발생량은 배양 48시간에 aspartic acid, malic acid 및 succinic acid첨가구에서 유의적(p<0.05)으로 높았고, 메탄 발생량은 lactic acid 첨가구에서 대조구보다 낮았다. 총 VFA와 propionic acid의 농도는 배양 12시간에 모든 첨가구가 대조구에 비해 높았다. 반추위 미생물 측정 결과에서는 Fumaric acid와 malic acid의 bacteria수가 대조구에 비해 유의적으로 증가하였으며(p<0.05), protozoa수는 유의적(p<0.05)으로 감소되었다. 이상의 실험 결과를 종합해 보면, organic acids의 첨가는 반추위 내 pH를 감소시키고 가스 발생량, 반추위 미생물 성장량 및 propionic acid 모두 증가시켰으며, 특히 lactic acid는 메탄생성을 억제하였다. 앞으로 Organic acid와 다른 메탄억제 물질과 혼합하여 반추위 내 메탄생성 억제에 관한 구체적인 연구가 필요한 것으로 사료된다. The objective of this study was to evaluate the in vitro effects of organic acids on methane emission and ruminal fermentation characteristics. We expected our methodology to result in a decrease of methanogens attached to the surface of rumen ciliate protozoa by addition of organic acids and in particular a decrease in methane emission. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Organic acids (aspartic acid, fumaric acid, lactic acid, malic acid, and succinic acid) known to be propionate enhancers were added to an in vitro fermentation system and incubated with rumen fluid. The microbial population, including bacteria, protozoa, and fungi, were enumerated, and gas production, including methane and fermentation characteristics, were observed in vitro. Organic acids appeared to affect the rumen protozoan community. The rumen protozoal popuation decreased with the addition of aspartic acid, fumaric acid, lactic acid, and malic acid. In particular, the methane emission was reduced by addition of lactic acid. The concentration of propionate with all organic acids that were added appeared to be higher than that of the control at 12 h incubation. Addition of organic acids significantly affected rumen bacteria and microbial growth. The bacteria in added fumaric acid and malic acid was significantly higher (p<0.05) and protozoa was significantly lower (p<0.05) than that of the control. Microbial growth with the addition of organic acids was greater than the control after 48 h incubation.

Protected Organic Acid Blends as an Alternative to Antibiotics in Finishing Pigs

Upadhaya, S.D.,Lee, K.Y.,Kim, In Ho Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.11

A total of 120 finishing pigs ([Yorkshire${\times}$Landrace]${\times}$Duroc) with an average body weight (BW) of $49.72{\pm}1.72kg$ were used in 12-wk trial to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, fecal micro flora, meat quality and fecal gas emission. Pigs were randomly allotted to one of three dietary treatments (10 replication pens with 4 pigs per pen) in a randomly complete block design based on their initial BW. Each dietary treatment consisted of: Control (CON/basal diet), OA1 (basal diet+0.1% organic acids) and OA2 (basal diet+0.2% organic acids). Dietary treatment with protected organic acid blends linearly improved (p<0.001) average daily gain during 0 to 6 week, 6 to 12 week as well as overall with the increase in their inclusion level in the diet. The dry matter, N, and energy digestibility was higher (linear effect, p<0.001) with the increase in the dose of protected organic acid blends during 12 week. During week 6, a decrease (linear effect, p = 0.01) in fecal ammonia contents was observed with the increase in the level of protected organic acid blends on d 3 and d 5 of fermentation. Moreover, acetic acid emission decreased linearly (p = 0.02) on d7 of fermentation with the increase in the level of protected organic acid blends. During 12 weeks, linear decrease (p<0.001) in fecal ammonia on d 3 and d 5 and acetic acid content on d 5 of fermentation was observed with the increase in the level of protected organic acid blends. Supplementation of protected organic acid blends linearly increased the longissimus muscle area with the increasing concentration of organic acids. Moreover, color of meat increased (linear effect, quadratic effect, p<0.001, p<0.002 respectively) and firmness of meat showed quadratic effect (p = 0.003) with the inclusion of increasing level of protected organic acid in the diet. During the 6 week, increment in the level of protected organic acid blends decreased (linear effect, p = 0.01) Escherichia coli (E. coli) counts and increased (linear effect, p = 0.004) Lactobacillus counts. During 12-wk of experimental trial, feces from pigs fed diet supplemented with organic acid blends showed linear reduction (p<0.001) of E. coli counts and the tendency of linear increase (p = 0.06) in Lactobacillus count with the increase in the level of organic acid blends. In conclusion, 0.2% protected organic acids blends positively affected growth performance, nutrient digestibility, fecal gas emission and meat quality in finishing pigs without any adverse effects on blood parameters.

Organic Acids Derived from Saliva-amalgamated Betel Quid Filtrate Are Predicted as a Ten-eleven Translocation-2 Inhibitor

Bhatkar Devyani,Ananda Nistha,Lokhande Kiran Bharat,Khunteta Kratika,Jain Priyadarshini,Hebale Ameya,Sarode Sachin C.,Sharma Nilesh Kumar 대한암예방학회 2023 Journal of cancer prevention Vol.28 No.3

There is a lack of evidence regarding the use of betel quid (BQ) and its potential contribution to oral cancer. Limited attention has been directed towards investigating the involvement of BQ-derived organic acids in the modulation of metabolic-epigenomic pathways associated with oral cancer initiation and progression. We employed novel protocol for preparing saliva-amalgamated BQ filtrate (SABFI) that mimics the oral cavity environment. SABFI and saliva control were further purified by an in-house developed vertical tube gel electrophoresis tool. The purified SABFI was then subjected to liquid chromatography-high resolution mass spectrometry analysis to identify the presence of organic acids. Profiling of SABFI showed a pool of prominent organic acids such as citric acid. malic acid, fumaric acid, 2-methylcitric acid, 2-hydroxyglutarate, cis-aconitic acid, succinic acid, 2-hydroxyglutaric acid lactone, tartaric acid and β-ketoglutaric acid. SABFI showed anti-proliferative and early apoptosis effects in oral cancer cells. Molecular docking and molecular dynamics simulations predicted that SABFI-derived organic acids as potential inhibitors of the epigenetic demethylase enzyme, Ten-Eleven Translocation-2 (TET2). By binding to the active site of α-ketoglutarate, a known substrate of TET2, these organic acids are likely to act as competitive inhibitors. This study reports a novel approach to study SABFI-derived organic acids that could mimic the chemical composition of BQ in the oral cavity. These SABFI-derived organic acids projected as inhibitors of TET2 and could be explored for their role oral cancer

유기산 종류와 pH의 차이에 따른 국산밀가루의 페이스팅 특성과 반죽 특성 및 제면 적성

왕 샤오,문유진,권미라 한국식품조리과학회 2019 한국식품조리과학회지 Vol.35 No.6

Purpose: This study investigated the effects of different pHs and organic acids on the activation of endogenous amylase in flour, the pasting property of flour and dough rheological property, and the noodle making performance. Methods: Korean domestic wheat flour was analyzed for activity of endogenous amylase, and the starch pasting property using a rapid visco analyzer (RVA) and the dough property using a mixograph at different pHs (3.0, 4.0, and 5.0) with various organic acids (citric acid, malic acid, lactic acid and acetic acid). In addition, the textural properties of cooked noodles made at those pHs with those organic acids were analyzed using a texture analyzer. Results: The amylase activity assay showed the decrease in the hydrolyzed starch content with the decreasing pH of organic acid solution. Further, different extents of the decrease were observed depending on the types of employed organic acids. The RVA pasting results showed significant relationships of pHs with the peak, breakdown, final and setback viscosities as well as the peak time and pasting temperature. The mixograph results also showed a noticeable change in the dough rheological property, which exhibited a more distinct peak pattern and narrower band width with decreasing pH. Firmness and chewiness of cooked noodles made with pH 5.0 of organic acid solution were higher than those of the noodles made with distilled water. Conclusion: The type and pH of organic acids significantly affected activation of the endogenous amylase in flour, starch pasting and the mixing property of flour, and also the textural property of cooked noodles. In particular, the combined effects of starch pasting and gluten development changed according to the pHs of organic acids were also significantly related to their performance in noodle making. This information can be applied to modify the texture of noodles.

Cosolvent System에서 이온성 유기화합물의 생분해 및 흡착 특성

최정민 ( Jeongmin Choi ),윤홍진 ( Hongjin Yun ),오동기 ( Dongki Oh ) 한국환경농학회 2023 한국환경농학회 학술대회집 Vol.2023 No.0

The existing cosolvency-induced sorption model, which is used to predict the fate of organic solutes in a cosolvent system, is not capable of completely explaining the effects of various interactions between solutes, solvents, and sorbents. Hence, this study aims to evaluate the effect of functional groups and aromatic rings on sorption onto activated carbon in a methanol-water system. The experiment was conducted on a hybrid bioreactor, which consists of a Sorption module and a biodegradation module, was investigated for the enhanced treatment of a organic acid mixture. Benzoic acid, 1-naphthoic acid, and 9-anthroic acid were chosen as organic sorbates, and activated carbon was used as the sorbent. We also summarized information on the biodegradation of each kind of organic acids under cosolvent system. As the microbial population increases, it shows high organic acids removal efficiency. The equilibrium concentrations were analyzed via GC-FID. As explained by the existing cosolvency model, for organic acids at pH 3 (i.e., pK_a>pH) and pH 7 (i.e., pK_a<pH), the sorption (K_m) of organic acids decreased on adding methanol. On the other hand, this study showed unexpected results that do not consistent with the existing cosolvency model. At pH 7 for the CaCl₂ system, K_m increases with increasing methanol volume fractions. A decrease in the dielectric constant of the liquid phase, caused by the presence of methanol, might result in an increase in K_m. Regardless of the cosolvency power (σ), as the number of aromatic rings in the solute increases, K_m is reduced in the order of benzoic acid > 1-naphthoic acid > 9-anthroic acid. In order to accurately predict the fate of acidic solutes in a variety of environment, studies for quantitatively estimating of effects of various interaction on the sorption should be conducted. Through the studies the current cosolvency induced sorption model can be advanced.

전통발효식품중의 유기산 함량 모니터링과 감식초 중의 항산화성 물질 분리

오금순,강길진,이진하,이강봉,김종환,박동희,고경희,이향미,안성모 식품의약품안전청 1998 식품의약품안전청 연보 Vol.2 No.-

전통발효식쭘인 된잣, 고추장, 간장 그리고 식초류중에 유jrl산 분표를 조사하고, 재래식과 개량식을 비요, 검토하였다. 또한 발효에 의해 천연적으로 프로피온산의 생성 유무를 확인f'.였으며,저장중의 유기산 변화 여루를 조사하였다. 한편 조미료뿐만 아터라 건강음료로 사용되는 감식초중의 항산화활성을 확인하였다. 간장에서 재래식은 lactic acid, citric acid, oxalic acid, succinic acid, propionic scid가, 개량식은 formic acid, citrlc acid, lactic acid, oxalic acid, acetic acid, suecinic acid가 검출되언으며 Propionic acid는 겊출되지 않았파. 된장의 경우 재래식은 lactic acid, acetic acid, citric acid, oxalic acid, formic acid, succinic acid, propionic acid가,개량식은 formic acid, citric acia, acetic acid, lactic ac펐, succinic acid, oTalic acid, propionic ac;긴가 검출죄었다. 고추장의 경우 재래식과 개량식에서 citric acid, atetic acid, formic acid, lactic acid, mallc acid, ox-alic acid, soccinic acid가 검출되었으며, 재래식에서만 prop'ionic ac;검가 검출되었다. 일반식초와 감식초의 줄요유기산은 acetic ac펐였으띠 , 감식초에서만 propionic acid가 조사되었다. 또한 실온과 35'c에서 9주간 저장실험한 결과 각 유기산 별로 뚜편한 변화를 보이지 않았다. 한편 감식초에서 출레놀함량은 nnic acid로서 366.Bs~989.77mg%범위였고, 항산화 활성은 ethyl acetate추출물이 r't장 활성력이 높았으며 그 활성은 BHT 또는 B됐A의 황 성과 비슷하였다. The studies that contents of organic acids in traditional and inoaified fermeated were compared and productioa of propionic acid with fermentation was investigated. Also we invested for chaBge organic acids during storage for 9· weeks at room temperature and 35'C . Tn addition, lue in-vestigated antioxidative activity in persimmon vinegar. The organic acids in traditional soysauce weudistributed lactic acidr acetic acid, citric acid, formic acid, succinic acid, oxalic acid and propionic acid.And the organic acids in modified soysauce were distributed formic acid, citric acid, oxalic acid, larticacid, acetic acid and succinic acid but propionic acid was not found. The organic acids in traditional andmodified soybean paste were distributed lactic acid, acetic acid, citric acid, oxalic acid. formic acid, suc-cinic acid aBd propionic aeid. The organic acids in traditional and modified JfocfuJanB· were distributedcitric acid, acetic acid, forTnic acid, lactic acid, malic acid, oxalic acid and succinic aeid, but propionicaicd was not found in modified Jfoeaujang. The major organic acid in persimmon and commercial vinrgars waffcetic acid, and propionic acid was found in persimmon vinegars alone. Also changes of organ-ic aicds composition in fermented foods during st,orage was not showed a remarkable difference. Totalphenolic compounds in persimmon vinegars was determined 366.85~909.77 fng% as tannic acid.Antioxidative activity of ethrlacetate fraction of IAhese phenolics showed higher than the other solvenH(n-hexane, chloroform) fractions and antioxidal÷ive activity was similiar to that of BHT or BHAactivity.

The Effects of Organic Acid on the Microalgae in the Food-waste Leachate Treatment

( Eun Ji Kim ),( Shan Zhang ),( Hyeon-jeong Hwang ),( Jae-hyeong Cho ),( Sun-jin Hwang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2015 No.-

There is about 80% organic acid in the Food wastes leachate and organic acid can be used as organic carbon source for mixotrophic microalgae. The mixotrophic cultivation is that the combination of autotrophic and heterotrophic cultivation, where inorganic and organic carbon sources are used in their methabolism simultaneously. Therefore, this study investigated the effect of various organic acid on the microalgae when Food wastes leachate treatment. Chlorella vulgaris was used in this study, also NaHCO₃ is supplied at all conditions as inorganic carbon source. In order to see the effect of organic carbon sources centrally, the carbon source conditions was set in 5 conditions - glucose known to have excellent effectiveness to increase of biomass productivity 1500 mg-COD/L, acetate 1500 mg-COD/L, isobutyrate 1500 mg-COD/L, propionate 1500mg-COD/L and the mixed organic acid (acetate, isobutyrate, propionate each 500 mg-COD/L). This study evaluated final biomass production, consumption of organic carbon, and N,P removal. In the result, the final biomass productivity by using glucose, acetate and isobutyrate is the highest level, followed by mixed organic acid and propionate. This is same aspect in N,P removal; the more rapid growth rate is, the more rapid N,P removal rate is. In the view of consumption of organic carbon, acetate make best use among organic acid.

한국 충남 및 전북에서 생산된 유기우유와 일반우유의 이화학적 특성에 관한 연구

기광석(Kwang Seok Ki),임동현(Dong Hyun Lim),박성민(Seong Min Park),임현주(Hyun Joo Lim),박수범(Su Bum Park),김태일(Tae Il Kim),정석근(Seok Geun Jeong),백광수(Kwang Soo Baek),권응기(Eung Gi Kwon),이세영(Se Young Lee) 한국식품과학회 2015 한국식품과학회지 Vol.47 No.3

본 연구는 한국의 충남과 전북지역에서 생산되는 유기우유와 일반우유의 이화학적 성분분석을 통해 차이점을 구명하고자 수행하였으며, 각 지역에서 유기우유 및 일반우유 생산농가를 각각 5개씩 선정하여 3회(2월, 3월 및 8월) 우유를 채취하였으며, 일반 성분, 무기물 및 지방산을 분석하였다. 유기우유의 유성분 중 유지방(p<0.01), 총 고형물(p<0.05), 유리지방산(p<0.01) 및 구연산(p<0.05)의 함량은 일반우유에 비해 유의적으로 낮았지만, 유단백질은 유의적으로 높았다(p<0.05). 유기우유의 유당, 우유 중 요소태 질소(MUN) 및 체세포수는 일반우유와 차이가 없었지만, MUN은 전북지역의 우유가 충남지역보다 높았다(p<0.05). 우유내 무기물 중 P의 함량만 유기우유에서 높았고(p<0.01), Ca, K, Mg, Zn 및 Fe의 함량은 차이가 없었다. 지방산 분석 결과, 우유내 지방산 중 함량이 높은 palmitic acid나 oleic acid에서는 유의적 차이가 없었지만, stearic acid와 총 포화지방산은 일반우유에서 높았다(p<0.01). 또한, 불포화지방산인 palmitoleic acid, linoleic acid, linolenic acid, eicosenoic acid, arachidonic acid는 유기우유에서 높았다(p<0.01). 따라서, 총 불포화지방산(p<0.01), 단일불포화지방산(MUFA, p<0.05) 및 고도불포화지방산(PUFA, p<0.01)의 함량도 유기우유에서 높게 나타났다. 본 연구결과, 한국의 충남 및 전북지역에서 생산되는 유기우유는 일반우유와 비교하여 지방함량 및 지방산 조성에서 많은 차이를 보였는데, 특히 유기우유는 건강에 유익한 고도불포화지방산의 함량이 높고, 소비자들은 식품의 안전성과 건강에 대한 관심이 커지기 때문에 앞으로 유기우유의 소비가 증대할 것으로 기대된다. This study was conducted to investigate the differences in the physicochemical properties of organic and conventional milk from Chungnam and Jeonbuk, Korea. The milk was collected from 10 organic and 10 conventional milk farms in February, March and August, and then analyzed for milk composition, minerals and fatty acids. Organic milk showed lower fat (p<0.01) and total solid (p<0.05), but higher phosphorous (p<0.01) content than conventional milk. However, there was no difference in the content of lactose or the somatic cell count. Organic milk showed lower (p<0.01) stearic acid and total saturated fatty acid content, but higher (p<0.01) total, mono-, and poly-unsaturated fatty acid content. These results showed that organic and conventional milks differ mainly in their fat and unsaturated fatty acid content. Due to increasing consumer interest in food safety and health, organic milk, which contains more beneficial fatty acids, might be preferred over conventional milk.

매실의 성숙중 향기 성분과 유기산의 변화

김광수,손영아,신승렬 경산대학교 생명자원개발연구소 1999 생명자원과 산업 Vol.3 No.-

매실의 향기성분은 50여종 중 알콜류가 benzyl alcohol, linalool, 1,6-octadien-3-ol, n-haxanol 등 10여종, aldehyde류가 2-hexenal, benzaldehyde, n-hexanal 등 3종, acid류가 butanedionic acid, acetic acid, 2종, 2-iodo-hexane 등 hydrocarbon류가 5종, butanedioic acid-diethyl ester를 포함한 ester류가 3종, β-ionone을 포함한 ketone류가 3종 그리고 기타 성분이 2종이었다. 매실이 성숙함에 따라 향기성분의 수가 증가하고 그 함량도 증가하는 경향이었다. 매실의 비휘발성 유기산의 조성은 succinic, fumaric, oxalic, malic, tartaric 및 citric acid이었다. 매실의 비휘발성 유기산은 성숙 초기에는 malic acid와 oxalic acid의 함량이 높았고, 성숙중기이후에는 malic acid와 citric acid의 함량이 높았다. Citric acid의 함량이 증가한 반면에 대부분의 유기산은 감소하는 경향이었다. 휘발성 유기산은 성숙중에 formic acid함량은 감소하고 butyric acid의 함량은 증가하는 경향이었다. 총 유기산의 함량은 매실 성숙에 현저히 감소하는 경향이었다. Apricot fruits were composited about 50 of flvor components, 10 of alcohol including benzyl alcohol, linaool, 1,6-octadien-3-ol. et al, 3 of aldehyde including 2-hexenal, benaldehyde, n-hexanal, 2 of acid including butannedionic acid, acetic acid, 5 of hydrocarbon including 2-iodo-hexane et al, 3 of ester including butanedioic aciddiethyl ester, 3 of ketone including β-ionone et al. Flavor components of apricot fruits were increased during maturation. Nonvolatile organic acids of apricot fruits were succinic, fumaric, oxalic, tartaric and citric aicd. Contents of malic and oxalic acid were high at 30, May, but contents of malic and citric acid were high after 9, June. Citric acid of nonvolatile organic acids was increased during maturation, but other were decreased during maturation. Formic acid of volatile organic acids was decreased during maturation, but butyric acid was increased. The contents of total organic acid was increased during maturation.

Chemical Properties and Spectroscopic Characteristics of Humic Fractions Isolated from Commercial Organic Fertilizers

김정제,양재의,신영오,Kim, Jeong-Je,Yang, Jae-E,Shin, Young-Oh 한국토양비료학회 1996 한국토양비료학회지 Vol.29 No.1

시판(市販)되고 있는 유기질비료(有機質肥料) 17 가지를 수거(收去)하여 부식특성(腐植特性)을 조사(調査)하였다 유기질비료(有機質肥料)에 함유(含有) 되어있는 내용물(內容物)의 종류(種類)는 다양(多樣)하였다. 예(例)를 들면 어박(魚粕), 유박(油粕), 주정박(酒精粕), 세르코-D, 부식토(腐植土), 톱밥. 토양개량제(土壤改良劑), 나무 껍질, 돈분(豚糞), 계분(鷄糞), 우분(牛糞), zeolite, 골분(骨粉), 토룡분(土龍糞), 낙엽(落葉), 아미노산 발효(發酵) 부산물(副産物), 석회(石灰), 가축(家畜) 부산물(副産物), 농산(農産) 부산물(副産物) 등등이었다. 물리화학(物理化學) 및 분광학적(分光學的) 특성(特性)은 다음과 같았다. 1. 유기질비료(有機質肥料)의 비료가(肥料價)는 유기질비료종류(有機質肥料種類)에 따라 큰 차이(差異)가 있었다. 2. 내용물중(內容物中)에는 부식화(腐植化)가 완전(完全)히 이루어지지 않은 유기물(有機物)이 있는 경우(境遇)도 있었다. 이것은 높은 C/N값으로 나타났다. 3. 대체(大體)로 한 가지 시료(試料)에서 추출(抽出)되는 humic acid의 양(量)이 fulvic acid의 양(量) 보다 많았다. 4. 부식화(腐植化)의 진전(進展)에 따라 humin의 상대적(相對的)인 양(量)도 증가(增加)하였다. 5. Total acidity는 phenolic hydroxyl group과 밀접(密接)한 상관관계(相關關係)가 있었으며 carboxyl group은 hydroxyl group과 alcoholic hydroctyl group과 유의성(有意性) 있는 상관관계(相關關係)가 있었다. 6. Humic acid와 fulvic acid의 UV 및 visible light absorption spectrum은 거의 같은 모양이었다. 7. 추출(抽出)된 humic acid의 종류(種類)는 B, P 그리고 Rptype이었다. Humic acid 중(中) 2가지는 B type, 3가지는 P type, 그리고 나머지 12가지는 모두 Rp type에 속(屬)했다. Humic substances of 17 organic fertilizers available on the market were the objects of study. The list of ingredients for formulation of them comprised fish meal. bone meal, oil-cakes, brewer's grains, peat, sawdust, wood bark, zeolite, soil conditioner, live-stock droppings, amino acid fermentation byproduct, chaff, limestone and others. Humic and fulvic acids were isolated from those substances and given chemical and spectroscopic analyses. Nutritional values of the organic fertilizers showed big diversity. Humification of organic matter was incomplete for some of the fertilizers as indicated by a high C/N ratio. Extractable humic acid percentage was higher, in general, than that of fulvic acid. Also the relative content of humin increased with advanced humification. Total acidity was closely related to phenolic hydroxyl groups. Relationships between carboxyl and hydroxyl groups. and carboxyl and alcoholic hydroxyl groups were very significant. Ultraviolet and visible light absorption spectra of humic and fulvic acids were substantially similar. The types of humic acids were B. P, and Rp. Two humic acids of the 17 samples belonged to B type. 3 to P type and all the rest to Rp type.