scholarly journals Bacteriocinogenic effect of Lactobacillus sakei 2a on microbiological quality of fermented Sardinella brasiliensis

2003 ◽  
Vol 46 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Milton L. P. Espírito Santo ◽  
Luiz H. Beirão ◽  
Ernani S. Sant'Anna ◽  
Eliana Bressa Dalcin ◽  
Bernadette G. M. Franco

Lactobacillus sakei 2a is a bacteriocin producer strain and, in this work, it's effects as a starter culture in the fermentation process of sardine (Sardinella brasiliensis) fillets were observed at different concentrations of NaCl (2, 4 and 6%) and glucose (2 and 4%), to determine it's ability to produce organic acids and consequent pH reduction. Experiments were carried out independently, with only one parameter (NaCl or glucose) varying at a time. After 21 days of fermentation the deteriorative bacteria concentration reached 9.7 Log10 CFU. g-1 corresponding to 6% NaCl and 4% glucose. Little differences were observed in lactic acid production when 2 and 4% glucose were added, since total acidity was 1.32 and 1.34% respectively, the experiments with 6% NaCl presented the best results. Initial pH of sardine fillets was 6 and after 21 days pH values were 3.8, 3.9 and 4 for the experiments with 2, 4 and 6% NaCl. This may have been due to the inhibitory properties of NaCl over the deteriorative bacteria. After 21 days of the fermentation process lactic acid bacteria concentrations were 14.5 Log10 CFU.g-1. The ratio protein nitrogen and total soluble nitrogen was typical of a cured fish.

Author(s):  
MILTON LUIZ PINHO ESPÍRITO SANTO ◽  
LUIZ HENRIQUE BEIRÃO ◽  
ERNANI SANT’ANNA ◽  
CESAR DAMIAN ◽  
BERNADETTE MELLO FRANCO

Lactobacillus sakei é comprovadamente uma cepa produtora de bacteriocinas e, neste estudo, procurou-se observar seus efeitos na fermentação de filés de sardinha ( Sardinella brasiliensis) em diferentes concentrações de NaCl e glicose. Verificou-se sua habilidade para produzir ácidos orgânicos e conseqüente redução do pH durante 21 dias de fermentação. Ao término desse período, a concentração de microrganismos deterioradores atingiu 9,7 log UFC g-1 correspondente a 6% de NaCl e 4% de glicose. Poucas diferenças foram observadas na produção de ácido lático quando se adicionou 2 e 4% de glicose, já que a acidez total foi 1,32 e 1,34%, respectivamente, para os experimentos com 6% de NaCl. O pH 6 inicial dos filés modificou-se ao término de 21 dias para 3,8, 3,9 e 4 nos experimentos com 2, 4 e 6% de NaCl. Tal comportamento pode ser atribuído ao poder inibidor do NaCl sobre a microbiota deterioradora. No término da fermentação, a concentração de bactérias ácido lácticas foi 14,5 log10 UFC g-1. A relação entre o nitrogênio protéico e o nitrogênio solúvel total mostrou-se típica de pescado salgado/curado em perfeitas condições de consumo. EVALUATION OF BACTERIOCINOGENIC ACTIVITY OF Lactobacillus sakei IN THE FERMENTETION OF TRUE SARDINE (Sardinella brasiliensis) BY UTILIZING GLUCOSE AS FERMENTABLE CARBOHYDRATE Abstract Lactobacillus sakei 2a is a bacteriocin producer strain and, in this study, it’s effects as a starter culture in the curing process of sardine ( Sardinella brasiliensis) fillets were observed at different concentrations of sodium chloride and glucose. It’s ability to produce organic acids and pH reduction during 21 days of fermentation was verified. After this period, the deteriorative microbiota concentration reached 9.7 log10 CFU. g-1 corresponding to 6% sodium chloride and 4% glucose. Little differences were observed in lactic acid production when 2 and 4% glucose were added, since total acidity was 1.32 and 1.34% respectively for the experiments with 6% NaCl. Initial pH of fillets was 6 and after 21 days pH values were 3.8, 3.9 and 4 for the experiments with 2, 4 and 6% NaCl. This may have been due to the inhibitory properties of NaCl over the deteriorative microbiota. At the end of the fermentation process lactic acid bacteria concentrations were 14.5 log10 CFU.g-1. The ratio protein nitrogen and total soluble nitrogen was typical of a cured fish under perfect eating conditions.


2005 ◽  
Vol 48 (1) ◽  
pp. 42-52 ◽  
Author(s):  
Milton Luiz Pinho Espirito Santo ◽  
Cristiane Lisboa ◽  
Fernanda Gonçalves Alves ◽  
Daniela Martins ◽  
Luiz Henrique Beirão ◽  
...  

Lactobacillus sakei 2a is a bacteriocin producer strain. In this study, it's effects as a starter culture in the curing process of sardine (Sardinella brasiliensis) fillets were studied at different concentrations of NaCl (2, 4, 6%) and glucose (2, 4%). After 21 days of fermentation, the spoilage microorganisms population reached 9.7 Log10 CFU g-1 corresponding to 6% NaCl and 4% glucose. With no addition of glucose and starter culture, sardine fillets began spoilage 72 hours after fermentation, even when 6% NaCl was used. Little differences were observed in lactic acid production when 2 and 4% glucose were added, since total acidity was 1.32 and 1.34% respectively, the experiments with 6% NaCl presented the best results. Initial pH of sardine fillets was 6.0 and after 21 days pH values were 3.8, 3.9 and 4.0 for the experiments with 2, 4 and 6% NaCl respectively. This could have been due to the inhibitory properties of NaCl over the spoilage microorganisms. After 21 days of the fermentation, the levels of lactic acid bacteria (LAB) were 14.5 Log10 CFU.g-1.


2011 ◽  
Vol 56 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Nenad Djordjevic ◽  
Goran Grubic ◽  
Bojan Stojanovic ◽  
Aleksa Bozickovic

The effect of different levels of compression (A1 = 420 gdm-1, A2 = 560 gdm-1) and inoculation (B1 = no inoculant, B2 = with inoculant) on changes in chemical composition, proteolysis and quality of lucerne silage was investigated in this paper. Based on the results of chemical analysis we found that in silages with more compressed material there was a reduction in the amount of ammonia nitrogen, soluble nitrogen and acetic acid, and increased content of protein nitrogen (?true?protein) and production of lactic acid (p<0.05). With the inoculation of the ensiling material the production of ammonia nitrogen and acetic acid was reduced but the content of lactic acid and acidity was increased (p<0.05). The interaction of both investigated factors (A?B) induced a decrease in the proteolysis degree, increase of lactic acid production and decrease in acetic acid production, and decrease in pH values (p<0.001) in investigated silages. The investigated factors had less influence on the chemical composition of lucerne material, and the significant variations were observed in fat and NFE contents. On the basis of this investigation the degree of compression is the most important parameter in ensiling technology. With the adequate compression and reduction of air in the starting material, the aerobic phase is reduced and the activity of proeolytic enzymes is decreased. In practice the special attention should be given to factors on which directly or indirectly the level of compression of ensiled material depends: wilting, cutting, object selection and/or selection of machines used for compression.


2015 ◽  
Vol 31 (3) ◽  
pp. 433-440
Author(s):  
B. Dinic ◽  
N. Djordjevic ◽  
J. Markovic ◽  
D. Sokolovic ◽  
M. Blagojevic ◽  
...  

In this study grape pomace was ensilaged without and with the addition of NPN substances (Benural) at the dose of 0.5, 1.0 and 1.5% of the amount of husk and with the addition of inoculant based on homo and hetero fermentative lactic acid bacteria. The greatest effect on the nutritional value had application of Benural, especially in increasing the CP content from 126.9 to 178.3 g kg-1DM, an increase of over 40%. Application of Benural increased the ammonia and soluble nitrogen several times, but even with the maximum addition of Benural percentage of ammonia nitrogen in the total nitrogen reached only slightly above 5% NH3-N/? N (5.38%), while the percentage of soluble nitrogen in total nitrogen was 28.29%. The application of inoculants generally had no significant impact, both on the chemical composition and the fermentation process.


2003 ◽  
Vol 69 (2) ◽  
pp. 1093-1099 ◽  
Author(s):  
Frédéric Leroy ◽  
Luc De Vuyst

ABSTRACT The use of bacteriocin-producing lactic acid bacteria for improved food fermentation processes seems promising. However, lack of fundamental knowledge about the functionality of bacteriocin-producing strains under food fermentation conditions hampers their industrial use. Predictive microbiology or a mathematical estimation of microbial behavior in food ecosystems may help to overcome this problem. In this study, a combined model was developed that was able to estimate, from a given initial situation of temperature, pH, and nutrient availability, the growth and self-inhibition dynamics of a bacteriocin-producing Lactobacillus sakei CTC 494 culture in (modified) MRS broth. Moreover, the drop in pH induced by lactic acid production and the bacteriocin activity toward Listeria as an indicator organism were modeled. Self-inhibition was due to the depletion of nutrients as well as to the production of lactic acid. Lactic acid production resulted in a pH drop, an accumulation of toxic undissociated lactic acid molecules, and a shift in the dissociation degree of the growth-inhibiting buffer components. The model was validated experimentally.


REAKTOR ◽  
2017 ◽  
Vol 5 (2) ◽  
pp. 79
Author(s):  
Abdullah Abdullah ◽  
H. B. Mat

The liquid pineapple waste contain mainly sucrose, glucose, fructose, and other nutrients. It therefore can potentiall be used as carbon source for organic acid fermentation. Recently, lactic acid has been considered to be an important raw material for production of biodegradadable lactace polymer. The experiments weree carried out in shake flash fermentation using lactobacillus delbroeckii. Effect of some parameters such as temperature, initial Ph, initial substrate concentration, yeast extract concentration and fermentation time to the yield have been studied. The highest yield was 85.65% achieved at 40 0C, PH 6.00, 52.2 g/l sugar concentration with 5 g/l yeast extract. There was no significant increasing in lactic acid production was observed if supplementation of yeast extract above 10%.Keyword : lactic acid fermentation, liquid pineapple waste, lactobacillus delbrueckii


1988 ◽  
Vol 51 (5) ◽  
pp. 386-390 ◽  
Author(s):  
Y. A. EL-SAMRAGY ◽  
E. O. FAYED ◽  
A. A. ALY ◽  
A. E. A. HAGRASS

The traditional yogurt starter, i.e. Staphylococcus thermophilus and Lactobacillus bulgaricus, has always been used to bring about the lactic acid fermentation during manufacture of concentrated yogurt known in Egypt as “Labneh”. Different combinations of some strains of Enterococcus faecalis, isolated from Laban Rayeb (a type of fermented milk), in combination with a certain strain of Lactobacillus bulgaricus were used to produce a Labneh-like product. Chemical, microbiological and organoleptic properties of the Labneh-like product were assessed and compared to the characteristics of Labneh processed traditionally by two different dairy plants in Egypt. All treatments showed similar changes during storage at 5 ± 1°C for 28 d. Total solids, fat, titratable acidity and pH values coincided with those of Labneh. Some components increased until the seventh day, i.e. acetaldehyde and diacetyl, while other features, such as the ratio of soluble nitrogen/total nitrogen and tyrosine, increased until the fourteenth day of storage. Thereafter, no marked variations occurred. However, a decrease in tryptophan content of all products occurred during the storage period. Total viable count and count of lactic acid bacteria of Labneh-like product as well as Labneh increased until the end of the second week of storage and then decreased. Coliforms, yeasts and molds and psychrotrophic bacteria were detected in some fresh and stored samples. The starter culture which consisted of 1.5% Enterococcus faecalis 19 and 1.5% Enterococcus faecalis 22 was used successfully to manufacture a Labneh-like product with high acceptability when fresh or refrigerated at 5 ± 1°C.


2004 ◽  
Vol 67 (2) ◽  
pp. 403-406 ◽  
Author(s):  
R. D. RAO ◽  
W. L. WENDORFF ◽  
K. SMITH

Whey is often stored or transported for a period of time prior to processing. During this time period, galactose and lactic acid concentrations may accumulate, reducing the quality of spray-dried whey powders in regard to stickiness and agglomeration. This study surveyed industry samples of Cheddar and mozzarella cheese whey streams to determine how galactose and lactic acid concentrations changed with storage at appropriate (4°C) and abuse (37.8°C) temperatures. Samples stored at 4°C did not exhibit significant increases in levels of lactic acid or galactose. Mozzarella whey accumulated the greatest amount of galactose and lactic acid with storage at 37.8°C. Whey samples derived from cheese made from single strains of starter culture were also evaluated to determine each culture's contribution to galactose and lactic acid production. Starter cultures evaluated included Streptococcus salivarius ssp. thermophilus, Lactobacillus helveticus, Lactobacillus delbrueckii ssp. bulgaricus, Lactococcus lactis ssp. cremoris, and Lactococcus lactis ssp. lactis. Whey derived from L. helveticus accumulated a significantly greater amount of lactic acid upon storage at 37.8°C as compared with the other cultures. Galactose accumulation was significantly decreased in whey from L. lactis ssp. lactis stored at 37.8°C in comparison with the other cultures. Results from this study indicate that proper storage conditions (4°C) for whey prevent accumulation of galactose and lactic acid while the extent of accumulation during storage at 37.8°C varies depending on the culture(s) used in cheese production.


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