Spoilage of Sous Vide Cooked Salmon (Salmo salar) Stored Under Refrigeration

2010 ◽  
Vol 17 (1) ◽  
pp. 31-37 ◽  
Author(s):  
P. Díaz ◽  
M.D. Garrido ◽  
S. Bañón
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Water Activity ◽  
Profile Analysis ◽  
Microbiological Quality ◽  
Quality Parameters ◽  
Texture Profile ◽  
Physical Chemical ◽  
Sous Vide ◽  
Aerobic And Anaerobic

The spoilage of Sous Vide ‘SV’ cooked salmon stored under refrigeration was studied. Samples were packaged under vacuum in polyamide—polypropylene pouches, cooked at an oven temperature/time of 80 °C/45 min, quickly chilled at 3 °C and stored at 2 °C for 0, 5 or 10 weeks for catering use. Microbial (aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae), physical—chemical (pH, water activity, TBARS, acidity, L*a*b* color, texture profile analysis and shear force) and sensory (appearance, odor, flavor, texture and overall quality) parameters were determined. SV processing prevented the growth of aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae. There were no relevant changes in pH, water activity, TBARS, CIELab color associated with cooked salmon spoilage. Instrumental texture data were contradictory. Slight decrease in lactic acid levels was found. In contrast, the SV cooked salmon suffered considerable sensory deterioration during its refrigerated storage, consisting of severe losses of cooked salmon odor and flavor, slight rancidity, discoloration associated with white precipitation, and moderates softness, and loss of chewiness and juiciness. No acidification, putrefaction or relevant rancidity was detected. The sensory spoilage preceded microbiological and physical—chemical spoilage, suggesting that microbiological quality alone may overestimate the shelf life of SV cooked salmon.

scholarly journals Microbiological Quality of Soft, Semi-Hard and Hard Cheeses During the Shelf-Life

2016 ◽  
Vol 39 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Josip Vrdoljak ◽  
Vesna Dobranić ◽  
Ivana Filipović ◽  
Nevijo Zdolec
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Shelf Life ◽  
Water Activity ◽  
Foodborne Pathogens ◽  
Challenge Test ◽  
Microbiological Quality ◽  
Growth Potential ◽  
Limiting Factor

AbstractCheeses as ready-to-eat food should be considered as a potential source of foodborne pathogens, primarily Listeria monocytogenes. The aim of present study was to determine the microbiological quality of soft, semi-hard and hard cheeses during the shelf-life, with particular reference to L. monocytogenes. Five types of cheeses were sampled at different time-points during the cold storage and analyzed for presence of Salmonella and L. monocytogenes, as well as lactic acid bacteria, Escherichia coli, coagulase-positive staphylococci, yeasts, molds, sulfite-reducing clostridia and L. monocytogenes counts. Water activity, pH and NaCl content were monitored in order to evaluate the possibility of L. monocytogenes growth. Challenge test for L. monocytogenes was performed in soft whey cheese, to determine the growth potential of pathogen during the shelf-life of product. All analyzed cheeses were compliant with microbiological criteria during the shelf-life. In soft cheeses, lactic acid bacteria increased in the course of the shelf-life period (1.2-2.6 log increase), while in semi-hard and hard cheeses it decreased (1.6 and 5.2 log decrease, respectively). Soft cheeses support the growth of L. monocytogenes according to determined pH values (5.8-6.5), water activity (0.99-0.94), and NaCl content (0.3-1.2%). Challenge test showed that L. monocytogenes growth potential in selected soft cheese was 0.43 log10 cfu/g during 8 days at 4°C. Water activity in semi-hard and hard cheeses was a limiting factor for Listeria growth during the shelf-life. Soft, semi-hard and hard cheeses were microbiologically stable during their defined shelf-life. Good manufacturing and hygienic practices must be strictly followed in the production of soft cheeses as Listeria-supporting food and be focused on preventing (re)contamination.

Efficacy of Nisin against Staphylococcus aureus in Experimentally Contaminated Sucuk, a Turkish-Type Fermented Sausage

2009 ◽  
Vol 72 (8) ◽  
pp. 1739-1743 ◽  
Author(s):  
HAMPARSUN HAMPIKYAN
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Water Activity ◽  
Aerobic Bacteria ◽  
Fermented Sausage ◽  
Subsequent Storage

Sucuk is a fermented sausage widely consumed in Turkey. The ability of different concentrations of nisin to inhibit Staphylococcus aureus in artificially contaminated sucuk was examined. Sucuk dough was prepared, inoculated with S. aureus ATCC 25923 at a level of 106 CFU/g, and then divided into six equal portions to which different concentrations of nisin (0, 25, 50, 100, 150, 200 μg/g) were added. Microbiological (S. aureus, total mesophilic aerobic bacteria, and lactic acid bacteria) and physicochemical (pH, water activity, and moisture) analyses were conducted initially and after 1, 3, 5, 10, 15, 20, 25, 30, 35, and 45 days. S. aureus populations decreased to below detectable limits in sucuk containing 200 or 150 μg of nisin per g after 30 and 35 days of storage, respectively, whereas S. aureus populations in 45-day-old sucuk containing 0, 25, 50, and 100 μg of nisin per g were 5.36, 5.68, 4.10, and 3.54 log CFU/g, respectively. Hence, the addition of nisin at 150 μg/g or greater to sucuk dough can be used to prevent the growth of S. aureus in sucuk during fermentation and subsequent storage.

scholarly journals Tokat Bez Sucuğunun Mikrobiyolojik Kalitesinin İncelenmesi

2020 ◽  
Vol 8 (12) ◽  
pp. 2683-2694
Author(s):  
Nesrin Kaval ◽  
Nilgün Öncül ◽  
Zeliha Yıldırım
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fecal Coliform ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Aerobic Bacteria ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Microbiological Parameters

In this study, the microbiological quality of traditionally produced Bez Sucuk in Tokat and its vicinity was investigated. For this purpose, 30 Bez Sucuk samples obtained from butchers, producers of Bez Sucuk, were analyzed for total count of mesophilic aerobic bacteria, lactic acid bacteria, yeasts-moulds, total coliform, fecal coliform, Staphylococcus aureus, Bacillus cereus, and Cl. perfringens. Also, the presence of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. were investigated in all samples. pH and water activity of the samples were determined. As the result of the analysis, the counts of the microbiological parameters investigated were found as follows: total mesophilic aerobic bacteria 3.5×106-4.23×109 CFU/g, lactic acid bacteria 5.55×105-2.45×109 CFU/g, yeasts and moulds 2.50×103-6.90×109 CFU/g, total coliform

Chemical and Microbiological Quality of Raw Milk Produced by Smallholder Farmers in Zimbabwe

1996 ◽  
Vol 59 (9) ◽  
pp. 984-987 ◽  
Author(s):  
A. N. MUTUKUMIRA ◽  
S. B. FERESU ◽  
J. A. NARVHUS ◽  
R. K. ABRAHAMSEN
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Smallholder Farmers ◽  
Microbiological Quality ◽  
Titratable Acidity ◽  
Raw Milk ◽  
Chemical Characteristics ◽  
Yeasts And Molds ◽  
Microbiological Analyses

Chemical and microbiological analyses were carried out on 10 samples of raw milk collected over 6 months from the Nharira/Lancashire Milk Collection Center. The milk center is run by smallholder farmers. The purpose of the study was to evaluate the quality of the raw milk delivered to the milk collection center. The average chemical characteristics of the milk were (%): titratable acidity expressed as lactic acid, 0.21; total protein, 3.19; fat, 3.52; total solids, 11.76; and solids not fat, 8.25; the pH varied from 6.15 to 6.65. There were large variations in the microbiological composition of the raw milk with total aerobic counts ranging from 6.2 × 103 to 7.8 × 107 CFU/ml, coli forms from 3.2 × 102 to 2.3 × 105, and lactic acid bacteria from less than 1 × 103 to 2.9 × 106 CFU/ml. Yeasts and molds were less than 100 CFU/ml in 7 of the 10 samples analyzed.

scholarly journals Quality and Safety of Marinating Breast Muscles of Hens from Organic Farming after the Laying Period with Buttermilk and Whey

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2393
Author(s):  
Anna Augustyńska-Prejsnar ◽  
Zofia Sokołowicz ◽  
Paweł Hanus ◽  
Małgorzata Ormian ◽  
Miroslava Kačániová
Keyword(s):  
Shear Force ◽  
Profile Analysis ◽  
Quality Parameters ◽  
Aerobic Bacteria ◽  
Texture Profile ◽  
Pseudomonas Spp ◽  
Quality Product ◽  
Microbiological Parameters ◽  
Physical Traits ◽  
Acid Whey

The material for the study was the breast muscles of hens after the laying period which were marinated with buttermilk and acid whey for 24 and 48 h. The quality parameters of non-marinated and marinated raw and roast products were evaluated in respect of physical traits (marinade absorption, pH, colour L*a*b*, shear force, TPA texture profile analysis test), microbiological parameters and sensory characteristics. The microbiological parameters were determined as the total viable counts of mesophilic aerobic bacteria of the Enterobacteriaceae family and Pseudomonas spp. Bacterial identification was performed by MALDI-TOF MS. The study showed that marinating the breast muscles of hens after the laying period with buttermilk and whey lightened the colour (p < 0.05), decreased the shear force value (p < 0.05), and reduced hardness and chewiness (p < 0.05) both after 24 and 48 h of marinating compared to the control product. The 24-h time of marinating with buttermilk and whey inhibited (p < 0.05) the growth of aerobic bacteria and Pseudomonas spp. and had a positive effect on the desirable odour, the intensity and desirability of flavour as well as the roast product tenderness. Longer marinating time reduced the product palatability and decreased its microbiological safety. The obtained results suggest that the 24-h time of marinating hen meat after the laying period with buttermilk and acid whey allows to obtainment of a high-quality product.

scholarly journals Non-thermal inactivation of Listeria spp. in a typical dry-fermented sausage: “Bergamasco” salami

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Erica Tirloni ◽  
Vanessa Di Pietro ◽  
Giuseppe Rizzi ◽  
Francesco Pomilio ◽  
Patrizia Cattaneo ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Production Process ◽  
Water Activity ◽  
Growth Potential ◽  
Worst Case ◽  
Fermented Sausage ◽  
Dry Fermented Sausage ◽  
Control Samples

Aim of the present study was the evaluation of the growth potential of Listeria spp. inoculated in the typical North Italian dry fermented sausage “Bergamasco” salami during its production. As it was necessary to carry out the challenge test in the production line of the industry, according to the guidelines of the European Reference Laboratory for Listeria monocytogenes, a non-pathogenic “surrogate” microorganism was used: for the inoculum, two strains of Listeria innocua (1 ATCC, 1 strain isolated from a similar substrate) were used. The inoculation of the samples occurred during grinding and mixing of the sausage mass, before the filling. To avoid cross-contamination, the control samples were produced before the contaminated ones. After the dripping, salamis were subjected to the normal production process (drying and maturation in five steps at specific temperatures and humidity rates). The inoculated products were subjected to the enumeration of Listeria spp. at T0 (day of inoculation) and at T4 (post-drying), and every 10 days during curing (T10, T20, T30, T40, T50, T60, T70, T80 and T90), as this salami is generally sold as whole piece with varying levels of curing (from T20 to T90). Since the product may be cut in half and vacuumpacked, at each of the times starting from T20, half salami was vacuum-packed and stored for 30 days at 12°C, at the end of the which Listeria spp. enumeration was performed again. At all times and for each type of samples of each of the three batches, the enumeration of the natural microflora (Total Viable Count, lactic acid bacteria, Pseudomonas spp., Enterobacteriaceae) and the determination of water activity and pH were performed on control samples. The product was characterized by a high concentration of microflora (8-8.5 Log UFC/g), consisting mainly of lactic acid bacteria, added to the mixture at the beginning of the production process. The pH showed a decrease over time, expected for this type of products, due to the development of lactic acid bacteria (final pH: 5.42-5.55). The water activity reached values able to inhibit the development of Listeria spp. (final aw: 0.826-0.863). Listeria counts in the tested batches of “Bergamasco” salami showed the absence of significant growth in the product with a reduction of loads if compared to T0, between -0.59 and -1.04 Log CFU/g. Even in the samples subjected to vacuum packaging and storage at 12°C, the absence of significant increase of lactic acid bacteria in the product was highlighted with further decrease of bacterial loads (-0.70/-0.79 Log CFU/g if compared to T20). Considering the worst case scenario (thus the batch with the highest growth potential), in the products stored in the curing room at 14-16°C, at humidity of 80% and in the samples stored at 12°C and vacuum packaged, the threshold indicated by the EURL Lm guidelines (+0.5 Log CFU/g) for the growth of Listeria spp. was not reached, allowing to classify “Bergamasco” salami in the category 1.3 of the EC Reg. 2073/2005 as “Ready-to-eat food unable to support the growth of Listeria monocytogenes”.

scholarly journals Potential Use of Lactic Acid Bacteria with Pathogen Inhibitory Capacity as a Biopreservative Agent for Chorizo

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1582
Author(s):  
Ruby Stella Lucumi-Banguero ◽  
Cristina Ramírez-Toro ◽  
German A. Bolívar
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Meat Products ◽  
Microbiological Quality ◽  
Chemical Additives ◽  
Nitrate Salts ◽  
Negative Effect ◽  
Cooked Meat ◽  
Potential Use ◽  
Protective Cultures

The biopreservation of meat products is of great interest due to the demand for products with low or minimal chemical additives. Lactic acid bacteria (LAB) have been used as protective cultures for many centuries. The objective of this work was to characterize 10 native LAB isolated from meat masses with biopreservative potential for meat products. The isolates were subjected to viability tests with different concentrations of NaCl, nitrite, and nitrate salts, pHs, and temperature conditions. Antibiotic resistance and type of lactic acid isomer were tested. In addition, the isolates were tested against seven pathogens, and inhibitory substances were identified by diffusion in agar wells. Finally, two isolates, Lb. plantarum (SB17) and Lb. sakei (SB3) were tested as protective cultures of chorizo in a model. As a result, the viability at different concentrations of NaCl and nitrate and nitrate salts were obtained. pH and temperature exerted a negative effect on the growth of some of the isolates. Pathogens were inhibited mainly by the presence of organic acids; P. aurius was the most susceptible, and S. typhimurium and S. marcescens were the most resistant. The strains SB17 and SB3 had similar effects on chorizo, and time exerted a deleterious effect on microbiological quality and pH. The results indicated that the 10 isolates show promising characteristics for the preservation of cooked meat products, with the strain Lb. plantarum (SB17) being the most promising.

scholarly journals A Relation between Exopolysaccharide from Lactic Acid Bacteria and Properties of Fermentation Induced Soybean Protein Gels

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 90
Author(s):  
Xiaoyu Yang ◽  
Jiao Feng ◽  
Qianqian Zhu ◽  
Rui Hong ◽  
Liang Li
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Water Distribution ◽  
Soybean Protein ◽  
Production Capacity ◽  
Gel Properties ◽  
Texture Profile ◽  
Protein Gel ◽  
Protein Gels ◽  
Α Helix

Exopolysaccharide (EPS) producing lactic acid bacteria (LAB) is considered to be an effective texture improver. The effect of LAB strains (different EPS production capacity) on physicochemical properties (texture profile, water distribution, rheological properties, and microstructure), protein conformation, and chemical forces of soybean protein gel was investigated. Correlations between EPS yield and gel properties were established. Large masses of EPS were isolated from L. casei fermentation gel (L. casei-G, 677.01 ± 19.82 mg/kg). Gel with the highest hardness (319.74 ± 9.98 g) and water holding capacity (WHC, 87.74 ± 2.00%) was also formed with L. casei. The conversion of β-sheet to α-helix, the increased hydrophobic interaction and ionic bond helped to form an ordered gel network. The yield was positively correlated with hardness, WHC, A22, viscoelasticity, and viscosity, but negatively correlated with A23 (p < 0.05). The macromolecular properties of EPS (especially the yield) and its incompatibility with proteins could be explained as the main reason for improving gel properties. In conclusion, the EPS producing LAB, especially L. casei used in our study, is the best ordinary coagulate replacement in soybean-based products.

scholarly journals Elaboration and Quality of Greek Yogurt (labneh) from Buffalo Milk Supplemented with Plus açaí jelly (Euterpe oleracea Mart.)

2021 ◽  
Vol 9 (1) ◽  
pp. 268
Author(s):  
Wagner Barreto Da Silva ◽  
Vanessa Vieira Lourenço-Costa ◽  
Higo Otávio Brochado Campos ◽  
Wânia Mendonça Dos Santos ◽  
Andréia Santana Bezerra ◽  
...  
Keyword(s):  
Nutritional Value ◽  
Bovine Milk ◽  
Microbiological Quality ◽  
Buffalo Milk ◽  
Raw Material ◽  
Euterpe Oleracea ◽  
Texture Profile ◽  
Physical Chemical ◽  
Special Programs ◽  
Euterpe Oleracea Mart

Buffalo milk has a high nutritional value, with high fat, protein, and mineral levels. Its derivatives yield exceeds by 40% those derived from bovine milk. As a way to take advantage of this quality, Greek yogurt (Labneh) is an alternative to add value to this important product. Thus, this work aims to prepare Greek yogurt with buffalo milk, added with açaí jelly (Euterpe oleracea Mart.), to carry out physical-chemical, microbiological, sensory, and texture profile analyzes in buffalo milk, Greek yogurt, and in açaí jelly. Natural Greek yogurt had an acceptability index of 90.11% and Greek yogurt with açaí jelly, 93.11%, which constitutes an alternative for regional raw material valorization, with excellent acceptability, high nutritional value, and outstanding physical-chemical and microbiological quality. Thus, this derivative is indicated for special programs supported by the City Halls and/or Government of Pará state, as a way of generating income and employment for communities producing buffalo milk and açaí.

scholarly journals Evaluation of physical-chemical and microbiological characteristics of freeze-dried and reydrated yogurt

2020 ◽  
Vol 9 (6) ◽  
pp. e14962446
Author(s):  
Shana Kimi Farias Yamaguchi ◽  
Carolina Krebs de Souza ◽  
Sávio Leandro Bertoli ◽  
Lisiane Fernandes de Carvalho
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fermentation Process ◽  
Guar Gum ◽  
Titratable Acidity ◽  
Chemical Characteristics ◽  
Physical Chemical ◽  
Microbiological Characteristics ◽  
Freeze Dried ◽  
Before And After

This study aimed to evaluate the physical-chemical characteristics and the viability of lactic acid bacteria during the fermentation process of the yogurt and after the freeze-dried process, in addition to testing three thickener formulations for the rehydration of the yogurt powder. During the fermentation process, the production of lactic acid and the growth of lactic acid bacteria were accompanied.  Before and after freeze-dried process, yogurt was analyzed for pH, titratable acidity, carbohydrates, proteins, lipids and viable lactic acid bacteria. After lyophilization, three thickener formulations were tested to evaluate the rehydration of powdered yogurt. At the end of the fermentation process, it was verified that the lactic acid bacteria grew to reach 7.8.107 UFC.g-1 and the acidity obtained was 9.27 g.L-1.  The viable lactic acid bacteria count of freeze-dried and non-freeze-dried yogurt was 5.6.107 CFU.g-1 and 7.8.107 CFU.g-1, respectively. Non-freeze-dried and freeze-dried yogurts showed a content of 20.8% and 21.0% carbohydrates, 4.0% and 3.6% protein and 3.7% and 2.7% lipids, respectively. The combination of thickeners that provided viscosity similar to commercial yogurts was the guar gum, pectin and maltodextrin mix. Thus, it was possible to verify that the freeze-drying process maintains the physical-chemical characteristics and viability of lactic acid bacteria. In addition, the developed yogurt presented easy reconstitution at the time of consumption.

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