Acid and Enzymatic Hydrolysis of an Acidic Polysaccharide from Soy Sauce

Mild acid hydrolysis of an acidic polysaccharide (APS-I) from soy sauce resulted in a degraded polysaccharide (DPS), the mixture of neutral sugar, D-galacturonic acid, its α-1,4-linked homologous di- and trisaccharides, and acidic oligosaccharides containing residues of D-galacturonic acid and L-rhamnose. Besides the above-mentioned sugars, an aldobiouronic acid containing D-xylose moiety was also yielded in the enzymatic hydrolysates with a crude polysaccharidase preparation. However, only a β-l, 4-galactobiose was isolated from the lower molecular fraction of enzymatic digest of APS-I with a typical hemicellulase preparation. DPS containing 83% of D-galacturonic acid was able to be degraded by endo-polygalacturonase, but APS-I was not because of its highly was discussed on the basis of these results, periodate oxidation study.     

Detailed Structure of an Acidic Polysaccharide in Soy Sauce,Confirmed by Use of Two Kinds of Purified Pectinases

The partially degraded polysaccharide obtained by means of mild acid hydrolysis of APS–I, an acidic polysaccharide in soy sauce, was incubated with an endo-polygalacturonase, and some acidic sugars liberated were fractionated and purified from the enzymatic hydrolyzate. They were identified as d-galacturonic acid (Gal A), its α-l,4-linked dimer and trimer, d-xylose (Xyl) β1→3 Gal A and Xyl β1→3 Gal A α1→4 Gal A, and an acidic polymer composed of the above-mentioned sugars through methylation analysis and other methods.

Methyl-esterized APS–I was subjected to β-elimination with pectin lyase or by heat treatment. The high molecular fraction which was highly resistant to β-elimination, was concluded to be β-1,4-linked d-galactan of which reducing-end group was attached to d-galacturonic acid. On the basis of these findings and previous knowledges, the construction of APS–I was also discussed.     

Isolation and Characterization of Acidic Peptides in Soy Sauce

A soy sauce sample was fractionated by gel filtration on a Sephadex G–15 column, then the fractions were subfractionated on the basis of acidity by ion exchange chromatography on a QAE-Sephadex A–25 column. The acidic subfractions with various acidities were further fractionated, using a preparative amino acid analyzer and by paper chromatography to separate the acidic peptide components.

Four dipeptides and sugar derivatives of ten dipeptides and two tripeptides were isolated and characterized as the major acidic peptides in soy sauce. However, it was difficult to anticipate any direct contribution of these peptides to the flavor construction in soy sauce on the basis of their contents and taste intensities.     

从老抽酱醪中分离耐盐性酵母的研究

以老抽酱醪为实验材料进行耐盐性酵母菌种分离,并做菌种鉴定。分析了在不同盐度条件下耐盐性酵母菌的生长情况和生长过程中培养基总糖的消耗,可以发现实验得到的酵母在22％（质量与体积}E）盐度下依然能够良好生长。结果表明,实验分离出的No．2菌在同级盐度的条件下的生长量要明显高于No．1菌,但在乙醇产率方面,两株菌在相同的含盐量为16％（质量与体积比）的麦芽汁培养基中发酵8d,No．1菌的乙醇产率为3．1％（体积比）,No．2菌的乙醇产率2．9％（体积比）。     

Non-enzymic Browning of Soy Sauce

Ion exchange resins have been used to separate soy sauce into three fractions of distinctly different composition: a cation fraction, a neutral fraction and an anion fraction. Almost all of the constituents responsible for browning were recovered in these three fractions.

Storage experiments show that when the three fractions were stored separately, only the cation fraction darkened considerably. When they were combined and stored, the color of the mixture increased at nearly the same rate as that of the original soy sauce. Neutral sugars are important constituents of the neutral fraction with respect to browning. The browning rate of a sugar-amino acid mixture (simulated soy sauce), was about 10% of soy sauce. The effect of the anion fraction (mainly caused by organic acids) and the ashed cation fraction on the over-all browning of soy sauce is calculated to be 1O~12% and 20%, respectively.

The sum of the contribution rate of the anion fraction, the neutral fraction, the amino acids and the ashed cation fraction in the browning of soy sauce was concluded to be approximately 40%. Compounds responcible for residual part of 60% should be considered to exist in the cation fraction. It was suggested that such compounds have strong reducing power and 0₂-uptaking ability.     

Isolation and Analysis of Molds from Soy Sauce Koji in Thailand

Five different isolates of Aspergillus and one of Mucor were compared with a Japanese commercial strain of Aspergillus oryzae for proteolytic activity on wheat bran substrate. One isolate of Aspergillus with superior protease production, identified as Aspergillus flavus var. columnaris, showed no detectable aflatoxin production on glutinous rice or soybean substrate. Preliminary tests using this fungus as a koji mold in a traditionally operated factory resulted in a soy sauce superior in quality to that usually produced.     

An Antioxidant Acidic Polysaccharide from Cuscuta chinensis

An acidic polysaccharide, H2, was isolated from the alkali-extract CHC of seeds of Cuscuta chinensis Lam. with the molecular weight more than 1.0×106. Chemical and spectroscopic studies led to the structure determination as follows: the backbone chain consists of 1,6-linked-β- D Galp, 1,4-linked-β- D Galp, 1,4-linked-β- D GalA and 1,2- or 1,4-linked-β- L Rhap having branching points at position O-3 of some 1,6-linked-β- D Galp residues (one among eight) and O-4 or O-2 of 1,2- or 1,4-linked-β- L Rhap residues to terminal β-D-galactopyranose. The side chains composed of terminal Galp, 1,6-linked-β- D Galp, 1,4-linked β- D Galp and 1,3,6-linked-β- D Galp also linked at position O-3 of 1,6-linked-β- D Galp residues in the backbone chain. β- L -arabinofuranosyl and terminal β- L -rhamnopyranosyl residues existed in the periphery of this polysaccharide linked to O-3 of 1,6-linked-β- D Galp residues in the backbone chain and the side chains. The polysaccharide H2 increased significantly the survival rate of PC12 cells indicating that it had protective effects against H2O2 insult.     

Mapping of Peptides in Soy Sauce by an Ion Exchange Chromatography

Pattern analysis of peptides in soy sauce was tried by gel filtration and ion exchange chromatography. In gel filtration through Sephadex G-15, the separation of smaller peptides and amino acids in soy sauce was found to be not so critical. Subsequently the mapping of peptides in soy sauce was done by ion exchange chromatography with Dowex 50-X2. Consequently it was estimated that there existed more than ten kinds of peptides in soy sauce.

Moreover, in the mapping of peptides, the automated measurement by the use of a discrete type analyzer, EEL Auto Chemist, was tried. The method developed here was not fully automated but available and effective for the mapping of peptides eluted from an ion exchange resin column.     

具有抗氧化活性的酸性菟丝子多糖H2的研究

从药用植物菟丝子 (CuscutachinensisLam .)的种子中经碱液提取所得的粗多糖CHC ,经进一步分离纯化得一酸性纯多糖H2 ,其分子量大于 1.0× 10 6,利用化学方法和光谱分析方法对其结构进行了研究。多糖H2由 1,6_linked_β_DGalp、1,4_linked_β_DGalp、1,4_linked_β_DGalA和 1,2or 4_linked_β_L_Rhap构成主链 ,并在部分1,6_linked_β_DGalp残基的O_3位和 1,2or 4_linked_β_L_Rhap残基的O_4或O_2形成分枝点 ,以末端半乳糖构成末端。侧链由末端半乳糖 ,1,6_linked_β_DGalp、1,4_linked_β_DGalp和 1,3,6_linked_β_DGalp残基构成 ,连接于主链的1,6_linked_β_DGalp残基的O_3位。阿拉伯糖残基 1,5_linkedAra、1,3,5_linkedAra、末端Ara以及末端鼠李糖残基存在于多糖分子H2的外周 ,连接于侧链和主链的 1,6_linked_β_DGalp残基的O_3位。此外 ,药理研究结果显示 ,H2能减少自由基引起的对大鼠成嗜铬细胞瘤PC12神经细胞系的损伤 ,明显提高细胞的存活率     

Isolation and Structural Analysis of an Acidic Polysaccharide from Astragalus membranaceus （Fisch.） Bunge

A new water-soluble hetero-polysaccharlde, APSID3, was obtained from a hot-water extract of the roots of Astragalus membranaceus （Flsch.） Bunge by DEAE-Sepharose Fast Flow and Sephacryl S-300 chromatography. The molecular weight of APSID3 was estimated to be 5.79 × 10^5 Da. Based on a sugar composlUon analysis, methylatlon analysis, partial hydrolysis and 13C nuclear magnetic resonance experimentation, It was concluded that the minimal repeat unit of APSID3 was composed of one terminal arablnose, one 1,5-1Inked arabinose, one 1,3-1Inked rhamnose, one 1,3,4-1Inked rhamnose, five 1,4-1Inked methyl galacturonates and six 1,4-1inked methyl glucuronates.     

胀罐酱油中耐渗透压酵母菌分离及鉴定

从广东某调味食品厂的3批次的胀罐酱油中分离到3株引起胀罐的耐渗透压的酵母菌,这些酵母菌在含有50％～60％葡萄糖和15％NaCl的培养基上生长较快,在普通酵母培养基上生长缓慢。通过对其进行形态特征观察和生理生化的测定,初步鉴定这3株酵母菌为埃切毕赤酵母（Pichia etchellsii）。     

Isolation and Characterization of Neutral Peptides in Soy Sauce

A soy sauce sample was fractionated by gel filtration on a Sephadex G–15 column, then the fractions were subfractionated on the basis of acidity by ion exchange chromatography on a QAE-Sephadex A–25 column. After preliminary fractionation, the components in the neutral subfractions were transformed to copper salts, and the salts were chromatographed on a DEAE-Sephadex A–25 column with a borate buffer and aqueous acetic acid to separate neutral peptide substances from a large amount of free amino acids. The peptide fractions were further fractionated on a preparative amino acid analyzer and by paper chromatography to separate the peptide substances.

Three glycodipeptides and eight dipeptides were isolated and characterized as the major neutral peptide components in soy sauce. However, it was difficult to anticipate any direct contribution of these peptides to the flavor construction in soy sauce on the basis of their taste intensities and contents.     

Acidic Arabinoxylan as an Exfracellular Polysaccharide of Suspension-Cultured Soybean Cells

An extracellular acidic arabinoxylan was obtained from the mediumof suspension-cultured soybean cells. The polysaccharide hada linear ß-1,4-linked D-xylopyranosyl backbone withboth neutral and acidic side chains. The acidic side chainswere glucuronosyl and 4-O-methyl glucuronosyl residues, andthe neutral side chains were arabinosyl and xylosyl residues. Although the amount of acidic arabinoxylan increased with theage of cultures, the percentage of acidic arabinoxylan in thewhole extracellular polysaccharides was almost constant duringthe growth period (2 to 8 days). (Received June 15, 1984; Accepted November 27, 1984)     

Persistence of Aflatoxin During the Fermentation of Soy Sauce

Aflatoxin was produced by Aspergillus parasiticus NRRL 2999 but not by A. oryzae during fermentation of soy sauce. Little aflatoxin was degraded within 6 weeks unless Lactobacillus delbrueckii also was present.     

高盐稀醪酱油发酵原油中微生物区系研究

对传统的高盐稀醪酱油发酵过程中的正常原油和异常原油中的微生物区系进行了分析,并对主要的细菌和酵母菌进行了菌种鉴定。同时,初步探讨了温度对原油中微生物区系的影响。实验结果表明,正常原油和异常原油中细菌总数、芽孢菌数、肠道杆菌、乳酸菌数和厌氧菌数没有明显差异,而酵母菌数和耐盐菌数有明显的差异。正常原油中优势酵母为球拟酵母属(Torulopsis)和酵母属(Saccharomyces),分别占酵母总数的55.9%和35.3%。异常原油中优势酵母为毕赤酵母属(Pichia)、假丝酵母属(candida)和酵母属(Saccharomyces),分别占酵母总数的62.8%、17.9%和9.0%。     

超声波降解紫球藻胞外多糖研究

通过测定溶液粘度,判断超声波降解紫球藻(Porphyridium cruentumi)胞外多糖的效果。运用均匀设计对超声波降解紫球藻胞外多糖的影响因素(处理振幅、时间、脉冲)进行优化,获得超声波处理的最佳条件:振幅39%、处理时间245s和脉冲9.5s。在最佳条件下,胞外多糖的粘度为2.98mm²/s,与预测值一致。采用DPS软件对实验结果进行二次多项式分析与拟合,并对模型和回归系数进行显著性检验,建立了以胞外多糖粘度为目标的回归方程式。     

Studies on the Activities of Bacteria in Soy Sauce Brewing

The activity of proteinases in soy masy juice was measured by a modification of the Anson’s method. Compared to proteinases of purely cultured soy koji digest which consisted of only Aspergillus proteinases, no difference was observed with the proteinases of usual soy mash through the studies of pH-proteinese activity curves, the inhibition test, and inactivation by acid and alkali treatment. It is supposed, therefore, that the proteinases in soy mash are mostly of Aspergillus origin. Viable counts on salted media, heat shocking at 80°C for thirty minutes, and the microscopic counts proved that there are very few Bacilli vegetative cells in soy mash. From these facts the author assumed that Bacilli mainly grow in the koji and survive in the soy mash mostly in the form of spores. This work also suggested that the so-called “Aspergillus alkaline proteinase” consists of two distinct proteinases, and further the existence of an inhibitor which only acts at pH8.     

Automated Measurement of L-Glutamate in Soy Sauce Using L-Glutamate Dehydrogenase

An automated method for rapid and convenient measurement of L-glutamate has been developed by using a discrete analyzer, EEL Auto Chemist. It is based on the colorimetric measurement of NADH produced on a mole-mole basis by enzymatic dehydrogenation of L-glutamate using L-glutamate dehydrogenase from bovine liver. The values of L-glutamate obtained by this method were well agreed with those obtained by the routine Waruburg mano-metric method using L-glutamate decarboxylase from Escherichia coli.     

An Acidic Polysaccharide Isolated from the Midrib of Leaves of Nicotiana tabacum

An acidic polysaccharide (APS-H) purified from the hemicellulosic fraction of the midrib of Nicotiana tabacum was composed of d-galacturonic acid, l-rhamnose, l-arabinose and d-galactose in a molar ratio of 31.8: 15.4: 9.9: 42.9. Its molecular weight was estimated to be 90,000 by gel filtration chromatography. APS-H had a pectin-like structure in which the rhamnogalacturonan backbone was composed of (1 → 2)-linked l-rhamnopyranosyl and (1 → 4)-linked d-galacturonosyl residues in a ratio of approximately 1: 2.1. It also contained (1 → 4)-linked d-galactan and (1 → 5)-linked l-arabinofuranosyl moieties as the side chains. Branch points occurred mainly at C-4 of (1 → 2)-linked l-rhamnosyl residues in the backbone and at C-6 of (1 → 4)-linked d-galactosyl residues in the side chains.