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Search Results: 1 - 10 of 17438 matches for " post-fermentation temperature "
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黄酒酿造后酵工艺对氨基酸态氮生成的影响
潘慧青,曹钰,石慧媛,陆健,谢广发
- , 2016, DOI: 10.3969/j.issn.1673-1689.2016.02.005
Abstract: 黄酒的氨基酸态氮是用来反映其中的氨基酸及小肽总体水平的重要指标,其含量的高低直接影响黄酒的质量等级和整体风味。作者针对黄酒后酵阶段工艺条件进行研究,通过对发酵过程中蛋白质、氨基酸态氮、活酵母数的动态变化以及酒体的理化指标和氨基酸组成分析,考察后酵时间和温度对氨基酸态氮生成的影响。结果表明,氨基酸态氮主要产生在黄酒后酵阶段,后发酵时间从14 d延长至17、20、23 d,氨基酸态氮的含量分别提高24.7%、31.7%和37.6%,酵母自溶过程对后酵末期氨基酸态氮的贡献显著。升高后酵温度有利于氨基酸态氮的形成,后酵温度对氨基酸态氮的形成同时受到蛋白质降解酶活性和酵母自溶两方面的综合影响。研究结果显示,氨基酸是氨基酸态氮的主要组成,其含氮量占氨基酸态氮60%以上。
Amino acid nitrogen (AAN) is an important indicator representing the overall level of amino acids and low molecular weight peptides in the Chinese rice wine,which content can affect the quality and flavor of wine. The influence of post-fermentation process parameters to AAN generating were discussed in this work,which included the post-fermentation time and post-fermentation temperature by tracing the dynamic changes of protein content,AAN content and amounts of viable yeast cells, Tricine analysis by SDS-PAGE,and the physicochemical indexes and amino acid composition of fermentation broth. The results showed that the post-fermentation was the main period for AAN producing. The content of AAN in draft rice wine was increased 24.7%,31.7% and 37.6%,respectively when post-fermentation time prolonged from 14 days to 17 days, 20 days and 23 days. Yeast autolysis process offered a significant contribution to AAN at end of post-fermentation. Meanwhile it had positive effect on AAN formation when post-fermentation temperature raised at range of 13 ℃ to 17 ℃. The results implied that AAN was influenced by both activities of protein degradation enzymes and the degree of yeast autolysis when post-fermentation temperature was changed. Furthermore,the work indicated that amino acids are the main composition of nitrogen compounds,which nitrogen content accounted for more than 60% of AAN. This study is aimed to understand the effect of process conditions on the AAN generating,which will benefit the quality improvement of Chinese rice wine
The Performance of by Turns Fermentation- Dryer for Vanilla (Vanilla Planifolia Andrews) Processing
Sitti Nur Faridah,,Abdul Waris,Haerani Haerani
IPTEK : The Journal for Technology and Science , 2011, DOI: http://dx.doi.org/10.12962/j20882033.v22i2.61
Abstract: The drying and fermentation are the processing steps which influence the quality of vanilla. Thus, an effort to produce instrument which can dry and ferment vanilla by turns automatically was done. Based on the test result on the instrument, it was known that the heater and heat-exchanger can function excellently. It can be seen from the increase of temperature after passing heater and heat-exchanger; and the decrease of air humidity in the drying chamber. The small differences of air flow speed between racks proved the uniformity of air flow speed in the drying chamber. The time and temperature control system showed temperature stability on drying process (i.e. 60°C) and on fermentation process (i.e. 40°C); moreover, temperature response reached 60°C and did not exceed the setting time (maximum 30 minutes). The water percentage depletion from 88% to 55% is relatively slow (in 5 days fermentation-drying process). The depletion is appropriate with the recommendation for fermentation-drying vanilla processing.
Screening of Acetic Acid Producing Microorganisms from Decomposed Fruits for Vinegar Production  [PDF]
Farzana Diba, Fahmida Alam, Ali Azam Talukder
Advances in Microbiology (AiM) , 2015, DOI: 10.4236/aim.2015.55028
Abstract: Acetic acid bacteria capable of growing at 30°C - 37°C were collected from various decomposed fruits available in Bangladeshi local markets in order to assess their suitability for vinegar production. Initially, 42 microorganisms were isolated from decomposed fruits like grapes, mangoes, pineapples, oranges, safeda etc. during summer when temperature reaches up to 37°C. Then their growths were checked in YPG medium containing various ethanol concentrations at different time point at 37°C. From the preliminary screening, 15 Gram negative bacterial isolates have produced halos or yellow zone around the colonies on YPG agar plate at 37°C which indicated acetic acid production capability by those bacteria. Furthermore, acetic acid production rates were determined by titration method and about 3 - 6.9 gm/100ml acetic acid were estimated by using 4% ethanol at 37°C by shaking culture for 3 days. Several biochemical analysis revealed that our collection contained huge amount of acetic acid producing bacteria and some of them could be potential candidates for vinegar production.
Efeito da adi??o de Lactobacillus sp. na ensilagem de cana-de-a?úcar
Valeriano, Alexandre Rocha;Pinto, José Cardoso;ávila, Carla Luiza da Silva;Evangelista, Ant?nio Ricardo;Tavares, Valdir Botega;Schwan, Rosane Freitas;
Revista Brasileira de Zootecnia , 2009, DOI: 10.1590/S1516-35982009000600006
Abstract: this study was aimed to evaluate the effect of microbial additives containing hetero fermentative or homo fermentative bacteria on the characteristics of sugarcane silages. sugarcane was inoculated with the following bacteria: lactobacillus plantarum (lp), l. paracasei (lpara), l. brevis (lbrevis), l.buchneri (lb), isolated from sugarcane silage, and three commercial inoculants, two of them containing l. buchneri (pioneer 11a44tm-lbp and lalsil cana-lblc) and one l. plantarum (biomax?-lpb) and control (without inoculation). all the inoculants were applied in population of 105 log cfu.g-1 of fresh forage. a completely randomized design was used with eight treatments and three replicates. the effect of inoculation on the bromatological characteristics was variable. the silage containing l. plantarum (lpb) showed significantly higher dry matter content (32.6%), while all the others strains studied showed similar effect, with average of 28.4%. the crude protein content ranged from 3.6-4.9% and ndf content ranged from 60-66.7% dm. the adf, hemicellulose and ash contents were similar for all silages. all treatments used more than 85% of the soluble carbohydrate, which resulted in ph around 3.5. the ph and ammoniacal nitrogen values were acceptable. the inoculants were more effective for the aerobic evaluation of silages, because they slow down temperature and improve the aerobic stability with best results observed in treatments lblc, lb and lpb.
Post Fermentation Quality Changes in Bobozi Produced from Cassava (Manihot Esculenta Crantz) and the Effects of Sodium Metabisulphite Soaking in Combination with Refrigeration
I.S. Ogiehor,G.I. Okwu,E. Enaigbe
Pakistan Journal of Nutrition , 2004,
Abstract: Changes in the microbiological, physico-chemical and organoleptic quality of bobozi (African snack) produced from cassava (Manihot esculenta Crantz) during processing and the effects of sodium metabisulphite or in combination with refrigeration at 10oC were investigated results shows that the bioload increased from 0.3 x 101cfu/g to 1.04 x 105 at the 96th hours of fermentation and thereafter decreased gradually. Post fermentation soaking in 5% sodium metabisulphite decongest and reduced the bioload to 0.9 x 101 cfu/g. Extended storage of 48hrs fermented samples indicates slightly high count which peaked at 1.11 x 104 at 21st day of storage for samples stored at ambient temperature (30 2oC) whereas the bioload of refrigerated (10oC) samples were stable all through the 28 days of storage. Six bacteria genera (Bacillus, Streptococcus, Staphylococcus, Leuconostoc, Lactobacillus, and Corynebacterium, E Coli, Klebsiella and Salmonella) and few fungi genera (Candida, Geotrichum, Aspergillus and Penicillum dominated the preboiling and fermentation phase while (3) three bacteria genera (Bacillus, Streptococcus and Lactobacillus) and three (3) fungi group (Geotrichum, Aspergillus, and Penicillum) dominated the post fermentation and extended storage phase. However, E coli, Klebsialla and Salmonella) were eliminated after boiling and were not detected after 24hour of fermentation. The PH decreased from 4.58 0.01 to 3.75 0.02 at the end of the fermentation period. Although slight increase as to 4.31 0.02 was recorded after soaking in Sodium metabisulphite. Further decreased to 3.61 0.01 was recorded in samples held at 30 2oC whereas it was fairly stable in refrigerated samples all through the storage period. However, reverse pattern of changes was observed and recorded in the titratable acidity. Steady increase from 31.20 0.5 to 46.6 0.4 was recorded for the moisture content at the end of the fermentation period. Slight increase was recorded in the post fermented sample held at 30 2oC. Nevertheless, sample stored at 10oC were fairly stable. The hydrocyanic acid decreased through out the processing and storage period. Overall sensory acceptability scores shows that refrigerated samples were highly acceptable even though freshly prepared samples were preferred.
Estabilidade aeróbia de silagens de capim-momba?a tratadas com Lactobacillus buchneri
ávila, Carla Luiza da Silva;Pinto, José Cardoso;Figueiredo, Henrique César Pereira;Morais, Augusto Ramalho de;Pereira, Odilon Gomes;Schwan, Rosane Freitas;
Revista Brasileira de Zootecnia , 2009, DOI: 10.1590/S1516-35982009000500001
Abstract: this study aimed to evaluate the effect of the addition of two l. buchneri strains on the aerobic stability of the momba?a grass silages. the experiment was carried out in a completely randomized design with three replicates in split-plot in time scheme, so that the treatments (silages without inoculant and with experimental or commercial inoculants) were randomized on plot and in times of aerobic evaluation of the silages (0, 2, 8, and 10 days after the opening of the silos) as subplots. after an storage period of 90 days, the silos were opened and samples of about 2,5 kg were collected for the evaluation of the aerobic stability based on the temperature for each sample. the chemical and microbiological changes in the silages were evaluated. as soon as the silos were opened, changes in the silages were observed, with increases in the lactic acid bacteria, yeast and filamentous fungus populations. also, the ph values increased due to the reduction in the organic acids concentration and to the increase in the dm and cp contents. the addition of l.buchneri to the silages increased their stability. the silages without inoculant was stable for 55 hours. the inoculated silages remained stable for 10 days. the improved stability was a consequence of an association of high acetic acid concentration with propionic acid and lower lactic acid concentration at the moment of silo opening, which resulted in inhibition of yeasts and molds.
Efecto de los Tratamientos post-cosecha sobre la Temperatura y el índice de Fermentación en la calidad del cacao criollo Porcelana (Theobroma cacao L.) en el Sur del Lago de Maracaibo
Portillo,E; Graziani de Farinas,L; Betancourt,E;
Revista de la Facultad de Agronomía , 2005,
Abstract: to establish the appropriate conditions of fermentation it is necessary to know the factors that influence on this, in such a sense it is of supreme importance to define the physical parameters that you/they reveal with more precision the particularities associated to the quality of the cocoa porcelana. the present work had as objective the evaluation of some factors post-crop that they influence on the fermentation like: fermentador type (tf), removal frequency (fr), it tolerated of the ear (am) and the time of fermentation (tpf). the methodology consisted at random on a design of blocks with a factorial arrangement where four factors were studied (tf, fr, am, tpf). the studied variables were: temperature of the mass of cocoa and the index of fermentation. the results showed highly significant differences (p<0,01) for all the factors of studies and for the two analyzed variables, in relation to the interactions, these they reflect that the maxima values of temperature (45,4°c) they were obtained in the square drawer and endurance zero. the removal treatments every 24 hours they also registered the biggest readings at the 72 hours of fermentation (46,5°c) and (46°c) in both cases. the index of more fermentation was obtained in square fermentadores (65,4%) and for the interaction (amxfr) the best combination is endurance five with removals every 24 hours at the 96 hours of initiate the process. finally the results allow to conclude that both variables obtain their maxima values in square fermentadores, endurance zero, removals every 24 hours and 72 hours of fermentation for temperature and 96 for the index of fermentation.
The Effect of Seed Extraction Methods on Seed Quality of Two Cultivar's Tomato (Solanum lycopersicum L.)
H. Nemati,T. Nazdar,M. Azizi,H. Arouiee
Pakistan Journal of Biological Sciences , 2010,
Abstract: In order to compare of different methods and identify the optimum condition for tomato seed extraction, factorial experiments with 3 replications was conducted. In the first experiment, pulp of two tomato cultivars (Faraon, Dominator) were fermented at two temperatures (25, 35°C) and six periods (24, 48, 72, 96, 120, 144 h). The germination of seeds in laboratory as well as seedling emergence and preliminary growth in greenhouse were studied and measured. The results showed that effect of cultivar on traits (except of seedling emergence) was significant. Also the effect of temperature of fermentation, duration of fermentation and also interaction effects of them on seed germination were significant. Totally seed quality decreased with increasing temperature and duration of fermentation and the fermentation duration from 24 to 48 h at temperature 25°C, is recommended. In the second experiment, tomato seeds were extracted by HCL (pH was arranged to 1, 2, 3 for 10, 20, 30 min), H2SO4 (pH was arranged to 1, 2, for 15, 30 min), Sodium carbonate (5, 10% for 24 and 48 h) and fermentation. Percentage germination, germination rate, length of radicle and length of plumule were used for seed quality assessment. The results showed that interaction effect between pH and duration of HCL treatments was significant for seed germination (percentage and rate) and there was an interaction effect between concentration and duration for germination rate in alkali treatments. Different extraction methods had not detrimental effect on percentage germination, but acid treatments produce very bright clean seeds in compare to other treatments.
Isolation of Starch Degrading Spoilage Bacteria from ‘Ogi’ (Fermenting Maize Starch)
A.W. Ashiru,O.D. Teniola,N.N. Dibiana,A. Apena
Pakistan Journal of Nutrition , 2012,
Abstract: Fermented maize starch known as ‘Ogi’ (Yoruba) or Akamu (Igbo) is a popular staple food and most popular traditional weaning food in West African countries. Its consumption by convalescents in these regions call for a safe product, free of pathogens and any potentially hazardous micro-organisms. The microorganisms associated with the spoilage of ‘ogi’ (fermented maize starch) porridge were isolated after seven day of fermentation. ‘Ogi’ off odour was first noticed at the 4th day of fermentation. Of all these bacteria and yeasts isolated, only bacteria could hydrolyze the starch in the ogi porridge and they were identified as Bacillus magaterium and Bacillus subtilis. The amylase activities of these organisms were studied under different temperature (20-80°C) and pH (2-8). The optimum temperature of both organisms was 40°C and optimum pH for Bacillus megaterium was four and that of Bacillus subtilis was two. Bacillus megaterium has higher amylase activity and thus was used to cause spoilage of sterile ogi porridge. The consistency of ‘Ogi’ change (liquefy) on the fourth day instead of the normal seven-day duration. In other to prevent ‘Ogi’ spoilage by Bacillus megaterium, a preservative, sodium benzoate was added to the sterile 'ogi' containing the inoculum, it was noticed that ‘Ogi’ aroma and colour remained the same but there was a little change in the consistency after seven days.
Effect of Temperature on Biochemical Changes Induced by Bacillus subtilis (SDA3) During Starter Culture Fermentation of Soybean into Condiment (Soy-Daddawa)
B.O. Omafuvbe
American Journal of Food Technology , 2008,
Abstract: In an attempt to upgrade the traditional fermentation technology of soybean into daddawa, the effect of fermentation temperature on the biochemical and organoleptic properties of soy-daddawa produced by starter culture was studied. Bacillus subtilis SDA3 previously selected as a good starter for soy-daddawa production was used to ferment sterile dehulled cooked soybeans at 25, 30, 35 and 40°C for 72 h. The viable cell counts of B.subtilis SDA3 increased throughout the 72 h fermentation process at 25 to 35°C while the counts decreased after the 24th h at 40°C fermentation. pH value increased throughout the fermentation with a rather low increase in the fermentation at 25°C. Relative proteolytic activity increased with fermentation, attained a peak at 48 h and then dropped in fermentations at 30-40°C. Proteolytic activity which was not detected by the 12th h increased thereafter till the end of the fermentation at 25°C. Free amino acid content increased throughout the 72 h fermentation at 30-40°C while an initial drop was observed in the first 12 h with subsequent increase till the end of the fermentation at 25°C. Alpha amylase activity increased, attained a peak at the 48 h and then dropped in 30 and 35°C fermentations. Alpha amylase activity increased throughout the 72 h fermentation at 25°C while at 40°C, the activity attained a peak at the 24th h and then dropped. Fermentation at 35°C gave the highest levels of proteolytic and alpha amylase activities, pH and free amino acids in soybean inoculated with B. subtilis SDA3. Organoleptically, soybean fermented by B. subtilis SDA3 at 35°C produced the best quality soy-daddawa as judged by a panel of regular soy-daddawa consumers. Fermentation at 35°C was therefore chosen as the optimised temperature for the production of soy-daddawa by B. subtilis SDA3 starter culture.
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