scholarly journals Inoculation with acetic acid bacteria improves the quality of natural green table olives

2021 ◽  
Vol 72 (2) ◽  
pp. e407
Author(s):  
M. Mounir ◽  
J. Hammoucha ◽  
O. Taleb ◽  
M. Afechtal ◽  
A. Hamouda ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Anaerobic Fermentation ◽  
Optimal Growth ◽  
Acetic Acid Bacteria ◽  
Growth Conditions ◽  
Industrial Processes ◽  
Table Olives ◽  
Olive Variety

This study aims to develop a method for the preparation of natural table olives using locally selected microorganisms and without resorting to the usual techniques which employ lye treatment and acids. The effects of parameters, such as lye treatment, inoculation with yeasts, substitution of organic acids with vinegar and/or acetic acid bacteria, and finally alternating aeration have been assessed. Four different combinations were applied to the “Picholine marocaine” olive variety using indigenous strains, namely Lactobacillus plantarum S1, Saccharomyces cerevisiae LD01 and Acetobacter pasteurianus KU710511 (CV01) isolated respectively from olive brine, Bouslikhen dates and Cactus. Two control tests, referring to traditional and industrial processes, were used as references. Microbial and physicochemical tests showed that the L3V combination (inoculated with A. pasteurianus KU710511 and L. plantarum S1 under the optimal growth conditions of the Acetic Acid Bacteria (AAB) strain with 6% NaCl) was found to be favorable for the growth of the Lactic Acid Bacteria (LAB) strain which plays the key role in olive fermentation. This result was confirmed by sensory evaluation, placing L3V at the top of the evaluated samples, surpassing the industrial one where a chemical debittering treatment with lye was used. In addition, alternating aeration served to increase the microbial biomass of both AAB and LAB strains along with Saccharomyces cerevisiae LD01 strain, but also to use lower concentration of NaCl and to reduce the deterioration of olives compared to the anaerobic fermentation process. Finally, a mixed starter containing the three strains was prepared in a 10-L Lab-fermenter from the L3V sample in order to improve it in subsequent studies. The prepared starter mixture could be suitable for use as a parental strain to prepare table olives for artisan and industrial application in Morocco.

Improvement of the Flavor and Quality of Watermelon Vinegar by High Ethanol Fermentation using Ethanol-Tolerant Acetic Acid Bacteria

2017 ◽  
Vol 13 (4) ◽  
Author(s):  
Yang Chen ◽  
Ye Bai ◽  
Dongsheng Li ◽  
Chao Wang ◽  
Ning Xu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethanol Fermentation ◽  
Cell Mass ◽  
Acetic Acid Bacteria ◽  
Acid Fermentation ◽  
Acetic Acid Fermentation ◽  
Essential Step ◽  
High Ethanol ◽  
Acceptance Score

Abstract Acetic acid fermentation is an essential step in the production of high-quality fruit vinegar and typically involves the use of acetic acid bacteria (AAB). The present study showed that the high cell mass and acetic acid yields of ethanol-tolerant AAB under high ethanol conditions were related to the high activities and stability of both pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase and PQQ-dependent aldehyde dehydrogenase. Additionally, in acetic acid fermentation with watermelon wine (8 % ethanol), the main organic acids (acetic, tartaric and malic acids) produced by ethanol-tolerant Acetobacter pasteurianus AAB4 were higher than those by conventional A. pasteurianus AS1.41 (1.42-fold, 3.53-fold and 2.12-fold, respectively). Also, the main esters (ethyl acetate and phenylethyl acetate) produced by AAB4 were higher than those by AS1.41 (1.69-fold and 1.48-fold, respectively). In addition, the total sweet and umami free amino acids produced by AAB4 increased significantly. According to sensory analysis, the flavor, taste and overall acceptance score of watermelon vinegar produced by AAB4 were significantly higher than those by AS1.41. Therefore, high ethanol fermentation with ethanol-tolerant AAB improved the flavor and quality of watermelon vinegar, indicating that this technology can be applied to fruit vinegar production.

scholarly journals Effect of Co-Inoculation with Saccharomyces cerevisiae and Lactic Acid Bacteria on the Content of Propan-2-ol, Acetaldehyde and Weak Acids in Fermented Distillery Mashes

2019 ◽  
Vol 20 (7) ◽  
pp. 1659
Author(s):  
Katarzyna Pielech-Przybylska ◽  
Maria Balcerek ◽  
Grzegorz Ciepielowski ◽  
Barbara Pacholczyk-Sienicka ◽  
Łukasz Albrecht ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Content ◽  
Isopropyl Alcohol ◽  
Quantitative Composition ◽  
Acetic Acid Content ◽  
Initial Ph

The qualitative and quantitative composition of volatile compounds in fermented distillery mash determines the quality of the obtained distillate of agricultural origin (i.e., raw spirit) and the effectiveness of further purification steps. Propan-2-ol (syn. isopropyl alcohol), due to its low boiling point, is difficult to remove by rectification. Therefore, its synthesis needs to be limited during fermentation by Saccharomyces cerevisiae yeast, while at the same time controlling the levels of acetaldehyde and acetic acid, which are likewise known to determine the quality of raw spirit. Lactic acid bacteria (LAB) are a common but undesirable contaminant in distillery mashes. They are responsible for the production of undesirable compounds, which can affect synthesis of propan-2-ol. Some bacteria strains are able to synthesize isopropyl alcohol. This study therefore set out to investigate whether LAB with S. cerevisiae yeast are responsible for conversion of acetone to propan-2-ol, as well as the effects of the amount of LAB inoculum and fermentation parameters (pH and temperature) on the content of isopropyl alcohol, acetaldehyde, lactic acid and acetic acid in fermented mashes. The results of NMR and comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC × GC-TOF MS) analysis confirmed the ability of the yeast and LAB strains to metabolize acetone via its reduction to isopropyl alcohol. Efficient fermentation of distillery mashes was observed in all tested mashes with an initial LAB count of 3.34–6.34 log cfu/mL, which had no significant effect on the ethanol content. However, changes were observed in the contents of by-products. Lowering the initial pH of the mashes to 4.5, without and with LAB (3.34–4.34 log cfu/mL), resulted in a decrease in propan-2-ol and a concomitant increase in acetaldehyde content, while a higher pH (5.0 and 5.5) increased the content of propan-2-ol and decreased acetaldehyde content. Higher temperature (35 °C) promoted propan-2-ol synthesis and also resulted in increased acetic acid content in the fermented mashes compared to the controls. Moreover, the acetic acid content rose with increases in the initial pH and the initial LAB count.

scholarly journals Profil Pertumbuhan Mikroorganisme pada Fermentasi Biji Kakao Aceh

2017 ◽  
Vol 9 (2) ◽  
pp. 50-54
Author(s):  
Murna Muzaifa ◽  
Yusya Abubakar ◽  
Faitzal Haris
Keyword(s):  
Acetic Acid ◽  
Fermentation Process ◽  
Acetic Acid Bacteria ◽  
Cocoa Bean ◽  
Chemical Changes ◽  
Crucial Step ◽  
Growth Profile ◽  
Cocoa Bean Fermentation

Fermentation process is the most crucial step in the formation of the flavor and aroma of the cocoa bean. Cocoa bean fermentation triggers an array of chemical changes within the bean.These chemical changes are vital to the development of the complex and much-loved flavour known as “chocolate”. Fermentation involves a number of specific microorganisms that play a role during fermentation. The aim of this research was to analized microorganism growth profil of Aceh cacao during fermentation. Fermentation was conducted on 6 days with  different aerations (agitation every 24 and 48 hours). The result showed that growth profile of microorganism during fermentation relatively  had similar trend. Yeast dominated on the early fermentation, lactid bacteria reached the higest population on day 3 and acetic acid bacteria on day 4. Better quality of fermented cacao was resulted on every 48 hours of agitation  that reached 70,19% of full fermentation.

scholarly journals Transcriptional regulation of SSA3, an HSP70 gene from Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (6) ◽  
pp. 3262-3267 ◽  
Author(s):  
W R Boorstein ◽  
E A Craig
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Double Mutant ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Hsp70 Gene ◽  
Base Pairs ◽  
Double Mutant Strain ◽  
Low Levels ◽  
Necessary And Sufficient

The SSA3 gene of Saccharomyces cerevisiae, a member of the HSP70 multigene family, is expressed at low levels under optimal growth conditions and is dramatically induced in response to heat shock. Sequences coinciding with two overlapping heat shock elements, located 156 base pairs upstream of the transcribed region, were necessary and sufficient for regulation of heat induction. The SSA3 promoter was also activated in an ssa1ssa2 double-mutant strain. This increase in the expression of SSA3 was mediated via the same upstream activating sequences that activated transcription in response to heat shock.

scholarly journals Study the Effect of pH on the Fermentation Anaerobic-Aerobic Siwalan (Borassus flabellifer L.) Sap to Produce Acetic Acid

2020 ◽  
Vol 21 (1) ◽  
pp. 29-35
Author(s):  
Elly Agustiani ◽  
Destri Susilaningrum ◽  
Atiqa Rahmawati ◽  
Fibrillian Z.L. ◽  
Dimas L.R.
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Ethanol Fermentation ◽  
Anaerobic Fermentation ◽  
Acetobacter Aceti ◽  
Aerobic Fermentation ◽  
Acetic Acid Production ◽  
Acid Product ◽  
Fermentation Time ◽  
Reducing Sugar Concentration

This research is to study the effect of ethanol fermentation aerobic pH on acetic acid product. Anaerobic fermentation uses saccharomyces cerevisiae to produce ethanol, and aerobic fermentation uses acetobacter acetic for acetic acid production. In aerobic ethanol fermentation using pH 3; 3.5; 4 and 5.  The ethanol concentration was evaluated using GC ULTRA Scientific Gas Chromatography, DSQ II detector, and MS 220 column. Acetic acid produced was analyzed using an alkalymetric method. Anaerobic fermentation uses Saccharomyces cerevisiae with 1-day log phase, while aerobic fermentation uses acetobacter aceti with a 5-day log phase. Fermentation using saccharomyces cerevisiae within 24 hours so that reduction sugar could stably decrease, optimum ethanol could be got at optimum pH 6 which could decrease 55 % of reducing sugar concentration to produce 8,20583 %v/v ethanol. Fermentation acetate acid content observed in 3 days at pH 6 and 30 ⁰C will produce 6,659 g/l also shows that pH 4-6 at 30 ⁰C will produce 6,605 g/l acetate acid. Aerobic fermentation of acetate acid in 3 days shows that pH 4-6 is highly affected by temperature at 30⁰C. Statistical analysis shows, in ethanol production pH and fermentation time give significant effect, but interaction has no significant effect.

scholarly journals Effect of Addition of a Specific Mixture of Yeast, Lactic and Acetic Bacteria in the Fermentation Process to Improve the Quality and Flavor of Cocoa Beans in Colombia

2020 ◽  
Vol 36 (2) ◽  
pp. 154-172
Author(s):  
Jorge Daniel Fonseca Blanco ◽  
Martha Del Pilar López Hernandez ◽  
Laura Sabrina Ortiz Galeano ◽  
Jenifer Criollo Nuñez ◽  
María Denis Lozano Tovar
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fermentation Process ◽  
Debaryomyces Hansenii ◽  
Lactobacillus Brevis ◽  
Acetic Acid Bacteria ◽  
Cocoa Beans ◽  
Inoculum Dose

Cocoa fermentation process is fundamental to generate flavors and aromas that are characteristics of chocolate. In Colombia, this process is carried out by microbiota that spontaneously colonizes cocoa beans, therefore the quality of the fermentation is inconsistent. Taking into account that the fermentation of cocoa beans is carried out by a consortium of microorganisms, the aim of thisresearch was to describe the effect of the addition of a specific mixture of yeasts, acetic acid bacteria, and lactic acid bacteria on the physicochemical and organolepticcharacteristics of cocoa beans (clone CCN 51). Isolates of two yeasts (Wickerhamomyces anomalus and Debaryomyces hansenii), three acetic acid bacteria (AAB), (Gluconobacter japonicus, Acetobacter tropicalis, and Acetobacter pasteurianus) and three lactic acid bacteria (LAB) (Pediococcus acidilactici, Lactobacillus brevis, and Lactobacillus plantarum) obtained fromprevious cocoa fermentations selected for their pectinases and acid production capacities in a specific mixture were used. Using the micro-fermentation technique, the effect of a biological starter was evaluated under different viable microorganismsratios (Yeasts: LAB: AAB as follows, 1: 1: 1, 1: 2: 2, 1: 2: 1, 1: 1: 2, 2: 1: 1, 2: 2: 1, 2: 1: 2, and 2: 2: 2). The concentration of each microorganism was standardized at 1x107 cfu/mL, then the biomass of 4 mL for ratio 1 and 8 mL for ratio 2 of each suspension of microorganisms was added at time zero. Different doses of inoculum were 0%, 1%, 2%, 3%, 4%, and 5% v/w mL inoculum/g cocoa beans. A beneficial effecton the sensory quality of cocoa beans was evidenced by the addition of microorganisms; the best proportion of microorganisms was 2:1:2 (yeasts:LAB:AAB) and the best inoculum dose was 3% (v/w) showing lower acidity, astringency, and bitterness, and emphasizing the cocoa flavors, fruity, nutty, and panela malt. 

V - III ratio effect on Cubic GaN Grown by RF Plasma Assisted Gas Source MBE

2001 ◽  
Vol 693 ◽  
Author(s):  
Li-Wei Sung ◽  
Hao-Hsiung Lin ◽  
Chih-Ta Chia
Keyword(s):  
Optimal Growth ◽  
Growth Conditions ◽  
Optical Quality ◽  
Rf Plasma ◽  
Stable Regime ◽  
Gas Source ◽  
Cubic Gan ◽  
Gas Source Mbe ◽  
N Flux

AbstractWe report the investigation on the growth conditions and optical properties of cubic GaN films grown on (001) GaAs substrate by using RF plasma assisted gas source MBE. The cubic GaN films were deposited at different Ga to N flux ratios that were determined by deposition rates directly. Three growth regimes, namely, Ga droplet, intermediate Ga stable, and N stable regime, are defined in the growth diagram. Optical quality of these films was determined by using photoluminescence (PL). Micro-Raman scattering were performed to analyze the crystallinity of the films. Optimal growth condition of cubic GaN is on the boundary of intermediate Ga stable regime and Ga droplet regime at a growth temperature of Ts = 720°C.

scholarly journals Acetic Acid Bacteria and the Production and Quality of Wine Vinegar

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Albert Mas ◽  
María Jesús Torija ◽  
María del Carmen García-Parrilla ◽  
Ana María Troncoso
Keyword(s):  
Acetic Acid ◽  
Technological Process ◽  
Oxidation Process ◽  
Acetic Acid Bacteria ◽  
Sensory Properties ◽  
Starter Cultures ◽  
Mixed Cultures ◽  
Wine Vinegar

The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either “fast” or “traditional”), the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties.

scholarly journals Optimization of growth conditions for forage production in a fresh forage growing system

2019 ◽  
pp. 759
Author(s):  
Do-Gyun Kim ◽  
Gyu-Wan Kim ◽  
Seung-Hyun Lee ◽  
Jong-Tae Park ◽  
Wang-Hee Lee
Keyword(s):  
Optimal Growth ◽  
Polynomial Equation ◽  
Growth Conditions ◽  
Forage Production ◽  
Cultivation System ◽  
Maximum Productivity ◽  
Validation Experiment ◽  
Temperature And Humidity ◽  
Central Composite

The optimization of growth conditions for a fresh forage cultivation system was performed herein to maximize the productivity of hulled barley by using response surface methodology. A central composite design was adopted to design experiments for determining the effects of two growth conditions: temperature (℃) and humidity (%). A second-order polynomial equation with the significant terms of temperature and humidity was developed (R-square = 0.937). The model predicted a maximum productivity of 12,568 g of barley at 19.7℃ and 62% humidity, and the validation experiment showed that the maximum productivity is consistently demonstrated at the predicted optimal conditions. In addition, ingredients analysis to determine the quality of barley suggested that the total ingredient contents were not considerably differentiated by different growth conditions. Consequently, this study successfully identified the optimal growth conditions for maximizing the yield of barley in the fresh forage system.

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