Cold smoking of Lebranche mullet (Mugil liza): Physicochemical, sensory, and microbiological evaluation

2020 ◽  
pp. 108201322095167
Author(s):  
Rolando Jimenez Lugo ◽  
Silvina Paola Agustinelli ◽  
María Isabel Yeannes ◽  
Marina Czerner
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Microbial Growth ◽  
Stability Range ◽  
Overall Acceptability ◽  
Smoked Fish ◽  
Ph Values ◽  
Nacl Concentration ◽  
Salty Taste ◽  
Bacterial Groups

The suitability of Mugil liza for cold smoking was evaluated and the effect of four different salting treatments on physicochemical, microbiological, and sensory characteristics was assessed. The addition of sucrose (3%) and acetic acid (0.5%) to the brine lead to fillet dehydration with lower NaCl penetration, combined with higher reduction of pH. Brining at refrigerated temperature (5 ± 1 ℃) instead of room temperature (16 ± 2 ℃) was more effective in preventing microbial growth. Loads of bacterial groups assessed in all smoked samples were below 100 CFU/g and the aw, moisture, NaCl, and pH values achieved were within the typical stability range of smoked fish products. The obtained products were characterized by the smoked aroma and salty taste, differing in 7 of the 21 evaluated descriptors. The use of acetic acid in brine formulation showed an effect over color and texture descriptors. The affective test indicated the overall acceptability of products, being preferred the samples treated in the lowest NaCl concentration (5%).

scholarly journals Enhanced Oil Removal by a Non-Toxic Biosurfactant Formulation

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 467
Author(s):  
Emília Mendes da Silva Santos ◽  
Isabela Regina Alvares da Silva Lira ◽  
Hugo Moraes Meira ◽  
Jaciana dos Santos Aguiar ◽  
Raquel Diniz Rufino ◽  
...  
Keyword(s):  
Room Temperature ◽  
Low Cost ◽  
Aeration Rate ◽  
Oil Removal ◽  
Central Composite Rotatable Design ◽  
Chemical Methods ◽  
Ph Values ◽  
Spectroscopic Analyses ◽  
New Formulation ◽  
Central Composite

In this study, a new formulation of low-cost, biodegradable, and non-toxic biosurfactant by Candida sphaerica UCP 0995 was investigated. The study was conducted in a bioreactor on an industrial waste-based medium, and a central composite rotatable design was used for optimization. The best results, namely a 25.22 mN/m reduction in surface tension, a biosurfactant yield of 10.0 g/L, and a critical micelle concentration of 0.2 g/L, were achieved in 132 h at an agitation speed of 175 rpm and an aeration rate of 1.5 vvm. Compositional and spectroscopic analyses of the purified biosurfactant by chemical methods, Fourier transform infrared spectroscopy, and nuclear magnetic resonance suggested that it is a glycolipid-type biosurfactant, and it showed no cytotoxicity in the MTT assay. The biosurfactant, submitted to different formulation methods as a commercial additive, remained stable for 120 days at room temperature. Tensioactive properties and stability were evaluated at different pH values, temperatures, and salt concentrations. The biosurfactant obtained with all formulation methods demonstrated good stability, with tolerance to wide ranges of pH, temperature and salinity, enabling application under extreme environmental conditions. Bioremediation tests were performed to check the efficacy of the isolated biosurfactant and the selected microbial species in removing oil from soil. The results demonstrated that the biosurfactant produced has promising properties as an agent for the bioremediation of contaminated soil.

Color and Antioxidant Changes in Various Natural Rubber Processes

2015 ◽  
Vol 754-755 ◽  
pp. 230-234 ◽  
Author(s):  
Suwimon Siriwong ◽  
Adisai Rungvichaniwat ◽  
Pairote Klinpituksa ◽  
Khalid Hamid Musa ◽  
Aminah Abdullah
Keyword(s):  
Acetic Acid ◽  
Natural Rubber ◽  
Retention Index ◽  
Total Phenolic Content ◽  
Room Temperature ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Lovibond Colorimeter

Fresh field natural rubber was coagulated by acetic acid, soaked in water at room temperature (WRT) or 70°C (W70) for 1 hr, and then dried in an oven at 40°C. Non-soaked natural rubber samples (NoW) served as a control. Two grades of natural rubber, namely air-dry sheet (ADS) and ribbed smoked sheet No.3 (RSS3) derived from the same latex, were also investigated. All dry rubber samples were characterized with Lovibond colorimeter according to ASTM D3157, as well as with a HunterLab spectrophotometer. Furthermore, all the dry rubber samples were dissolved in a chloroform:methanol mixture (4:1 v:v). The rubber was then precipitated out of the solution with methanol, and the remaining solution was quantitatively analyzed for total phenolic content (TPC). The plasticity retention index (PRI) was determined for all the dried rubber samples according to ASTM D3194. It was found that WRT, W70 and ADS were similar in lightness L*, while RSS3 had the lowest L*. W70 had the lowest redness a*, which increased in the order WRT, NoW, RSS3 and ADS. W70 also had the lowest yellowness b*, which increased in the order RSS3, NoW and WRT and ADS. Moreover, TPC was the lowest for the W70 sample, increasing in the order ADS, WRT, NoW and RSS3. The PRI was highest for W70, and decreased in the order WRT, RSS3, NoW and ADS. All of the PRI values observed were comparatively high relative to blocked standard Thai rubber 20 (STR20).

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

Bacterial Spoilage of Citrus Products at pH Lower than 3.51

1976 ◽  
Vol 39 (12) ◽  
pp. 819-822 ◽  
Author(s):  
B. J. JUVEN
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Thermal Resistance ◽  
Tartaric Acid ◽  
Lactobacillus Brevis ◽  
Acid Inhibition ◽  
Temperature Range ◽  
Ph Values ◽  
Sugar Syrup ◽  
Z Value

A strain of Lactobacillus brevis, L-3, was isolated from a blown can of grapefruit segments in sugar syrup; it caused spoilage of citrus products having pH values lower than 3.5. When inoculated into orange (pH 3.38) and grapefruit (pH 2.99) juices, after 5 h at 30 C L-3 produced 15 and 22 μg diacetyl/ml, respectively, and off-flavor was detectable. L-3 grew in APT broth acidified to pH 3.0 with citric, hydrochloric, phosphoric, or tartaric acid. However, its growth was inhibited at pH 3.6 if the acidulant was lactic acid, while with acetic acid inhibition occurred at a pH between 3.7 and 4.0. The thermal resistance of L-3 in orange serum (pH 3.4) was studied in the temperature range of 52 to 60 C: a z value of 8.3 was obtained. A simple and reliable capillary technique for studying the thermal resistance of gas-producing organisms in liquid foods and media is presented.

Effect of pH, Acidulant, Time, and Temperature on the Growth and Survival of Listeria monocytogenes

1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Malic Acid ◽  
Incubation Temperature ◽  
Growth And Survival ◽  
Ph Values

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).

GROWTH OF STAPHYLOCOCCUS AUREUS IN ACIDIFIED PASTEURIZED MILK1

1970 ◽  
Vol 33 (11) ◽  
pp. 516-520 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth
Keyword(s):  
Staphylococcus Aureus ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Hydrochloric Acid ◽  
Ph Value ◽  
The Other ◽  
Antagonistic Effects ◽  
Pasteurized Milk ◽  
Ph Values ◽  
Effect On Growth

The effect of gradually reducing the pH of pasteurized milk with acetic, citric, hydrochloric, lactic, and phosphoric acids over periods of 4, 8, and 12 hr on growth of Staphylococcus aureus 100 in this substrate was determined. In addition, 1: 1 mixtures of lactic acid and each of the other acids, and of acetic and citric acids were evaluated for their effect on growth of this organism. To achieve a 90% reduction in growth over a 12 hr period, a final pH value of 5.2 was required for acetic, 4.9 for lactic, 4.7 for phosphoric and citric, and 4.6 for hydrochloric acid. A 99% reduction during a 12 hr period was obtained with a final pH value of 5.0 for acetic, 4.6 for lactic, 4.5 for citric, 4.1 for phosphoric, and 4.0 for hydrochloric acid. A pH value of 3.3 was required for a 99.9% reduction with hydrochloric acid, whereas the same effect was produced at a pH value of 4.9 with acetic acid. Correspondingly lower pH values were required to inhibit growth within 8 and 4 hr periods. Mixtures of acids adjusted to pH values at the borderline for growth (12 hr period) exhibited neither synergistic nor antagonistic effects between two acids.

scholarly journals Chemisorption of acetic acid onSi(100)−2×1at room temperature

2008 ◽  
Vol 77 (11) ◽  
Author(s):  
Han-Koo Lee ◽  
Ki-jeong Kim ◽  
Jin-hee Han ◽  
Tai-Hee Kang ◽  
J. W. Chung ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Room Temperature

Mitigating the Antimicrobial Activities of Selected Organic Acids and Commercial Sanitizers with Various Neutralizing Agents

2011 ◽  
Vol 74 (5) ◽  
pp. 820-825 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Room Temperature ◽  
Sodium Thiosulfate ◽  
Antimicrobial Activities ◽  
Phosphate Buffered Saline ◽  
Lactic Acids

This study was conducted to evaluate the abilities of five neutralizing agents, Dey-Engley (DE) neutralizing broth (single or double strength), morpholinepropanesulfonic acid (MOPS) buffer, phosphate-buffered saline (PBS), and sodium thiosulfate buffer, in mitigating the activities of acetic or lactic acid (2%) and an alkaline or acidic sanitizer (a manufacturer-recommended concentration) againt the cells of Shiga toxin–producing Escherichia coli (STEC; n = 9). To evaluate the possible toxicity of the neutralizing agents to the STEC cells, each STEC strain was exposed to each of the neutralizing agents at room temperature for 10 min. Neutralizing efficacy was evaluated by placing each STEC strain in a mixture of sanitizer and neutralizer under the same conditions. The neutralizing agents had no detectable toxic effect on the STEC strains. PBS was least effective for neutralizing the activity of selected organic acids and sanitizers. Single-strength DE and sodium thiosulfate neutralized the activity of both acetic and lactic acids. MOPS buffer neutralized the activity of acetic acid and lactic acid against six and five STEC strains, respectively. All neutralizing agents, except double-strength DE broth, had a limited neutralizing effect on the activity of the commercial sanitizers used in the study. The double-strength DE broth effectively neutralized the activity of the two commercial sanitizers with no detectable toxic effects on STEC cells.

scholarly journals Preparation of Whey-Based Banana Beverage and its Quality Evaluation

2021 ◽  
Vol 5 (01) ◽  
pp. 60-66
Author(s):  
Kunjal Shrestha ◽  
Abhishek Dahal
Keyword(s):  
Sensory Analysis ◽  
Room Temperature ◽  
Storage Time ◽  
Value Added ◽  
Body Color ◽  
Overall Acceptability ◽  
A Value ◽  
Banana Juice ◽  
Nutritional Qualities ◽  
The One

A value-added functional beverage was formulated utilizing unprocessed whey with excellent nutritional qualities and bland flavors; along with banana juice and the required amount of sugar. Five different formulations were prepared with varying proportions of whey, banana juice, and sugar. Sensory analysis was carried out for all five formulations and based on statistical analysis the one which showed the highest value for body, color, flavor, taste, and overall acceptability was selected for further analysis (85% liquid whey and 15% banana juice). The shelf-life of the final product was observed for 30 days at room temperature (25±5°C) and refrigerated temperature (7±1ºC). A significant variation in body, color, flavor, taste, and overall acceptability were observed by varying the composition of whey and banana juice (p<0.05). The beverage was pasteurized at 82.5°C for 20 min and stored at normal (25±5°C) and refrigerated (7±1°C) for 30 days. The effects of storage time and temperature on physicochemical (TSS, pH, acidity) and microbial (TPC, yeast & mold count) properties were evaluated. Out of five formulations, the one selected via sensory analysis had TSS of 12.4°Bx, total solids 14.21%, 0.302% acidity, pH 5.72, 5.087% reducing sugar, 0.53% protein, 0.56% ash, 0.87% crude fiber, 184.43mg potassium (mg/100gm) and 0.912mg vitamin C in 100 ml. The prepared beverage was stored for 30 days under refrigerated and normal conditions, and changes in TSS, pH and acidity were observed: 12.413.3%, 5.72-5.214, 0.32-0.43%, and 12.4-13.8%, 5.72-4.64, 0.32-0.68% respectively. Overall analysis showed that the beverage prepared with 85% liquid whey and 15% banana juice could be stored for 30 days under refrigerated conditions without the addition of preservatives.

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