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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Chemical, Biochemical and Physical Treatments on the Kinetics and on the Role of Some Endogenous Enzymes Action of Baker’s Yeast Lysis for Food-Grade Yeast Extrac ผู้เขียน:S. Boonraeng, P. Foo-trakul, W. Kanlayakrit, C. Chetanachitra สื่อสิ่งพิมพ์:pdf AbstractThe effects of chemical, biochemical and physical treatments on lysis of baker’s yeast cells were studied at pH 5.2 and temperature 54 ?C. An unstructured kinetic model of first order was developed to understand the mechanism of yeast lysis. The autolysis rate constant (k), yield factor for protein (?P), total carbohydrate (?C) and autolysate (?A) were sensitive to disruption methods. Since there were endogenous enzymes in the yeast cells such as proteinases, glucanases and carboxypeptidases, these enzymes were responsible for synergistic of cell disruption and their activity profiles were affected by different treating methods. From the determined results of amino acids composition in yeast autolysate, there were differences in amino acid content. The biochemical treated sample using 0.1% papain gave the highest total amino acid content among all analysed samples. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Hybridization and Selection of Saccharomyces cerevisiae Strains from Industrial Baker’s Yeasts) ผู้เขียน:นางฉกามาศ วงศ์ข้าหลวง, Yasuo Nakatomi, Hiroyuki Takano สื่อสิ่งพิมพ์:pdf AbstractHybridization study of two Saccharomyces cerevisiae baker’s yeast strains isolated in Thailand, IFRPD 6080 and IFRPD 6081, was carried out. Rare-mating technique has been employed with haploid and diploid mating strains of Japanese baker’s yeast. Polyploid (triploid and tetraploid) hybrids produced from rare-mating were selected and induced for sporulation. Screening of segregants obtained from individual spore clones of the hybrids was performed by determination of their characteristics, i.e. yield of yeast after cultivation, total carbohydrate and trehalose contents of obtained yeast, and carbon dioxide (CO2) production during fermentation with bread dough. Two segregants, 6080xs4D s27 and 6080xs4D s39 derived from the parental strain IFRPD 6080 and one segregant, 6081xs34D s12 from the parental strain IFRPD 6081, with desirable characteristics were obtained as the new strains. These segregants possessed good growth yield and higher maltose fermentation ability than their parents. Carbon dioxide productions in non-sugar, low-sugar and high-sugar dough were also markedly improved. Moreover, the strain 6080xs4D s27 acquired certain freeze-tolerant ability from mating strain and was able to use for frozen dough preparation. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Characterization of New Baker’s Yeast Strains And Their Leavening Ability in Bread Dough) ผู้เขียน:นางฉกามาศ วงศ์ข้าหลวง, นางมาลัย เมืองน้อย (บุญรัตนกรกิจ) สื่อสิ่งพิมพ์:pdf AbstractTwo new Baker’s yeast strains obtained from hybridization of commercial baker’s yeast parent strains, Saccharomyces cerevisiae IFRPD 6080 and IFRPD 6081 with Japanese mating strains were investigated. The hybrids, IFRPD 6171 from parent strain 6080 and IFRPD 6173 from parent strain 6081, were evaluated for their characteristics, namely growth, total carbohydrate and trehalose contents, sugar fermentation ability, cryoresistance at -20 ?C and their leavening ability in bread doughs. Both hybrids had good growth and higher maltose and sucrose fermentation abilities than their parents. Carbon dioxide productions in non-sugar, low-sugar and high-sugar dough were also markedly improved. In addition, hybrid 6171 possessed cryoresistance or freeze-tolerant ability in low-sugar dough and could be used for frozen dough preparation. Quality evaluation of white and sweet breads made from hybrids also showed better quality than their commercial parent strains. Thus, the hybrid 6171 was suitable for both white (low-sugar) and sweet breads (high-sugar) whereas hybrid 6173 was particularly good for sweet bread. Moreover, hybrid 6173 was also high in maltose fermentation ability and produced very high carbon dioxide in non-sugar dough, which indicated favorable characteristic to be used in nonsugar bread such as French bread. |
หัวเรื่อง:การปรับสภาพที่เหมาะสมด้วยวิธีทางเคมีชีวภาพและกายภาพสำหรับการย่อยสลายยีสต์ขนมปังเพื่อผลิตยีสต์สกัด ผู้เขียน:นายประศาสตร์ ฟูตระกูล, ผู้ช่วยศาสตราจารย์, Supot BOONRAENG, Weerasit Kanlayakrit, Charan Chetanachitra สื่อสิ่งพิมพ์:pdf AbstractThe effects of chemical, biochemical and physical treatments on baker?s yeast lysis were studied. The standard conditions for autolysis were pH 5.2, temperature 54?C and yeast concentration 13% dry wt. The optimum chemical treatment obtained by using 5% v/v ethanol and 5% w/v NaCl. The optimum biochemical and physical treatments were the use of 0.1%w/w of papain and 8,000 psi of homogenization respectively. The combination treatment of 5% ethanol and 5% NaCl exhibited highest protein content (61.90%).The physical treated sample obtained 42.45% of total carbohydrate yield and biochemical treated sample obtained 46.53% of autolysate. The chemical analysis of the samples showed the best result in the biochemical treated sample as (g/100g dry wt): 57.50 of total protein, 8.22 of amino-nitrogen, 24.27 of carbohydrate, 7.86 of nucleic acid and 10.72 of ash contents. This treatment showed the feasibility of producing yeast extract, yeast autolysate at pilot plant or industrial scale. |
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หัวเรื่อง:- ผู้เขียน:Ilyas Baker สื่อสิ่งพิมพ์:pdf AbstractAlthough key agencies in the field of natural resources management do not have a comprehensive manpower development strategy, many staff will at some time attend development aid funded overseas degree level and post-graduate level courses, as well as overseas and in-country short-term courses. The last mentioned are becoming more and more popular with aid agencies and Thai counterparts although their effectiveness has never been established. The difficulties of assessing these are acknowledged and some subjective comments based on the author's experience are submitted. These relate to organization, the use of technical specialists, course content and language medium. Some comments on development aid training policy are also made and finally some suggestions are put forward whech if inplemented may contribute towards more effective manpower development strategies in the field of natural resources management. The existence of a sufficient quantity of skilled natural resource managers is without a doubt a key determinant of Thailand's successful sustainable development. Although manpower needs have never been formally quantified, the shortage is apparent and attempts to deal with this have already been implemented. Key agencies in the field of natural resources, rarely, if at all, have a comprehensive manpower development strategy, but nevertheless take advantage of opportunities to send dtaff to development aid funded overseas degree level and post-graduate level courses, as well as overseas and in-country short-term courses. The last mentioned are becoming more and more popular with aid agencies and Thai counterparts but their effectiveness has never been established. The business of assessing technical co-operation training activities is fraught with difficulty (Muscat, 1986) and perhaps this is why evaluation usually focuses on the direct or immediate project objectives using highly subjective self-completion questionnaires. Admittedly, it is difficult to find a satisfactory alternative means of assessment but this must not inhibit discourse among aid donors, the Thai government, technical experts, course organizers and course participants. Unless such discourse takes place aid foud and manpower are likely to remain inefficiently used and new and possibly more appropriate training initiatives are unlikely to be forthcoming. With regard to these training activities, I will restrict my comments to short-term in-country training programs as over the past few years I had some experience of these. After this some comments on development aid training policy will be made. |
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ผลงานตีพิมพ์ในวารสารวิชาการLow-Power Circuits for Brain-Machine Interfacesผู้แต่ง:Rahul Sarpeshkar, Dr.Woradorn Wattanapanitch, Associate Professor, Scott K. Arfin, Benjamin I. Rapoport, Soumyajit Mandal, Michael W. Baker, Michale Fee, Sam Musallam, Richard A. Andersen, วารสาร: |