• 제목/요약/키워드: Chemical products

검색결과 3,813건 처리시간 0.033초

장류제품의 아미노산 조성과 그 단백질 품질평가에 관한 연구 (Studies on the Amino Acid Composition of Korean Fermented Soybean Meju Products and the Evaluation of the Protein Quality)

  • 이철호
    • 한국식품과학회지
    • /
    • 제5권4호
    • /
    • pp.210-214
    • /
    • 1973
  • 한국 재래식 장류 및 개량식 제품과 중간 가공물인 메주와 koji-mix 및 원료 대두에 대한 아미노산 조성과 available lysine 함량을 분석하고 이로부터 각 제품의 단백질 품질평가를 시도하였으며 Eggum의 단백질 chemical score와 biological value 와의 상관회귀 방정식을 이용하여 각 제품 단백질의 대략적인 biological value를 추산하였다. 메주용 대두의 amino-N 함량은 총 질소량의 85%에 달하나 장류 제품에는 총 질소량의 약 75%의 amino-N 함량으로 감소하는 반면 $NH_3-N$ 과 기타 N-compounds 함량이 증가한다. 이중 가내제조된 간장은 예외적으로 낮아 총 질소량의 53%에 불과한 amino-N을 함유하고 있다. 장류제조에서 재래식 방법과 개량식 제품 단백질의 질적변화의 차이는 크게 나타나지 않으며, 메주제조 단계까지는 원료 대두단백질의 영양가가 크게 손상되지 않으나 사임 담금이후 후숙 분리과정에서 단백가가 크게 손상되어 제품의 단백가는 원료 대두 단백질의 약 1/2에 불과한 chemical score를 나타내며 약 $1/3{\sim}1/2$에 미달되는 낮은 lysine 가용도를 갖게된다.

  • PDF

농산부산물(農産副産物)의 사료화(飼料化) (Improving Feed Value of Agricultural By-Products)

  • 강태홍
    • Applied Biological Chemistry
    • /
    • 제27권
    • /
    • pp.18-28
    • /
    • 1984
  • In order to improve feed values of Korean agricultural by-products, various treatments including physical, chemical, physicochemical and fermentation were suggested in th is review article. Physical treatments such as chopping, grinding and pelleting reduce partiole size of agricultural by-products, and increase passage rate from the rumen, thus may increase voluntary feed intake and weight gain. Digestibility and voluntary feed intake of straw, rice hull and sawdust, also, may be increased by chemical treatment using sodium hydroxide or ammonia. Especially, because nitrogen content of by-products increase and toxic problem is not posed by ammonia treatment, it's practical usage is recommended in Korea. Silage or fermentation treatment using principles of microbial fermentation may improve palatability of low quality by-products. As mentioned above, it is concluded that various treatments suggested are desirable and improve feed value but may raise several problems. Unfortunately, because cost for installation and products is great and processing work is complicate, farmers are not using well these processing methods until now. Therefore, in order to increase the practical usage at farm level, it is thought that many research works be achieved for efficient process which have simple operation and low installation cost.

  • PDF

Gaseous by-products from the TiO2 Photocatalytic Oxidation of Benzene

  • Han, Sang-Wook;Lee, Jin-Hong;Kim, Jin-Seog;Oh, Sang-Hyub;Park, Young-Kwon;Kim, Hyun-Ook
    • Environmental Engineering Research
    • /
    • 제13권1호
    • /
    • pp.14-18
    • /
    • 2008
  • Photocatalytic oxidations of benzene gas using the closed system (batch reactor) were induced to determine its by-products and investigate the effect of humidity and oxygen concentration on their generation. The study was able to identify 11 gaseous by-products: 2-methylpropene, acetaldehyde, acetone, pentane, methylcyclobutane, methylcyclopentane, cyclohexane, 2,3-dimethylbutane, 2-methylpentane, 3-methylpentane, and hexane. All the by-products were saturated hydrocarbons, which are less toxic than benzene and were probably formed through hydrogenation reaction on the photocatalytic surface. The photocatalytic oxidation of benzene under higher humidity produced less by-products. However, the amount of acetone released increased with higher humidity and oxygen concentration.

Mild Isomerative Opening of Tetrahydrofuranyl Subunits in Steroids Using TFAT (trifluoroacetyl trifluoromethanesulfonate): Application to Synthesis of C17-OH Rockogenin Acetate

  • Lee, Jong-Seok;Kim, Byung-Sook;Shin, Jun-Ho;Lee, Yeon-Ju;Shin, Hee-Jae;Lee, Hyi-Seung
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권1호
    • /
    • pp.76-82
    • /
    • 2012
  • A novel and efficient tetrahydrofuranyl ring opening method was developed using the highly reactive TFAT reagent in the presence of an acid scavenger, 2,6-di-tert-butyl-4-methylpyridine. Various acid sensitive groups are compatible with the reaction condition, making it generally applicable to many tetrahydrofuranyl steroids. Moreover, it is a synthetic equivalent of 'Marker degradation' affording an efficient synthesis of C17-OH rockogenin acetate.

Influence of the Structural Characteristics of Amino Acids on Direct Methylation Behaviors by TMAH in Pyrolysis

  • Choi, Sung-Seen;Ko, Ji-Eun
    • Bulletin of the Korean Chemical Society
    • /
    • 제30권11호
    • /
    • pp.2542-2548
    • /
    • 2009
  • Direct methylation behaviors of 20 amino acids with tetramethylammonium hydroxide (TMAH) were studied under diluted conditions with silica. Amino acid concentration was controlled by dilution with silica ($SiO_2$) and the molar ratios of amino acid/silica were 0.20, 0.50, and 2.0. The molar ratios of amino acid/TMAH (0.51 - 4.64) also varied. It was found that arginine, asparagine, aspartic acid, cysteine, glutamic acid, and glutamine did not generate any directly methylated pyrolysis products, whereas alanine, glycine, isoleucine, leucine, methionine, phenylanaline, valine, and proline generated all the directly methylated pyrolysis products. Tri- and tetra methylated products of lysine consisted of two types. Histidine and threonine hardly generated the partly methylated products. Mono- and dimethylated products of serine, tryptophan, and tyrosine were not observed. Relative intensities of the methylated products varied with the amino acid concentration, TMAH concentration, and pyrolysis temperature. Direct methylation behaviors of amino acids were explained by the structural characteristics of amino acids.

Chemical Recycling of Rigid and Flexible Polyurethanes as Raw Materials

  • Lee, Dai-Soo
    • 한국고분자학회:학술대회논문집
    • /
    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
    • /
    • pp.212-212
    • /
    • 2006
  • Polyurethane wastes can be depolymerized with glycols and/or amines. The depolymerization products may be recycled for the preparation of various polyurethanes. Caprolactam was employed to depolymerize Spandex fibers and the depolymerization products were evaluated as raw materials for the preparation of polyurethane elastomers. The depolymerization products were homogeneous and could be used to prepare polyurethane elastomers acceptable for various applications as binders.

  • PDF