Effect of Chemically Adjusted Meat pH and Drying Air Velocity on some Properties of Dry Sausage

1975 ◽  
Vol 38 (12) ◽  
pp. 764-768 ◽  
Author(s):  
W. E. TOWNSEND ◽  
C. E. DAVIS ◽  
A. J. MERCURI

Effects of chemically adjusted meat pH (lowered by calcium chloride; raised by sodium hydroxide-sodium citrate), and velocity of air during drying on some properties of a dry type sausage were investigated. During the first 2 days of drying, sausages having initial pH values of 5.5 had a more intense cured meat color than those having initial pH values of 5.9 or 6.6. During 21 days of drying. pH 5.5 sausages showed very little change in shape, while sausages with pH values of 5.9 and 6.6 exhibited triangular and twisted triangular cross-sectional shapes. respectively. Sausages having initial pH values of 5.5 and dried with high air velocity had poor internal cured meat color and texture and developed hollow centers, but not in those having pH values of 5.5, 5.9, or 6.6 and dried with low air velocity. Peelability improved during drying.

1955 ◽  
Vol 1 (5) ◽  
pp. 299-311 ◽  
Author(s):  
R. Steel ◽  
C. P. Lentz ◽  
S. M. Martin

Factors affecting the production of citric acid in the submerged fermentation of ferrocyanide-treated beet molasses by Aspergillus niger were studied in 2.5 and 36 liter fermenters. The small fermenters were used to determine the effects of changes in sterilization technique, phosphate supplement, ferrocyanide treatment, inoculum level, initial pH, fermentation temperature, and aeration rate. The relation between ferrocyanide concentration and inoculum level was also studied. Four different samples of molasses were fermented successfully. An average yield of 8.2% citric acid (64% conversion) was obtained from 51 small-scale fermentations. Comparable yields were obtained in the large fermenters under comparable conditions. Most of the information obtained with the small fermenters was applicable to the larger-scale fermenters, but in the latter the fermentation was significantly more stable. Aeration was the main problem in the scale-up and aeration rates approximately double those calculated on a fermenter cross-sectional area basis were required for comparable results in the large fermenters.


2009 ◽  
Vol 60 (9) ◽  
pp. 2345-2352 ◽  
Author(s):  
Z. Liao ◽  
Z. Gu ◽  
M. C. Schulz ◽  
J. R. Davis ◽  
J. C. Baygents ◽  
...  

This research investigated the effectiveness of electrocoagulation using iron and aluminium electrodes for treating cooling tower blowdown (CTB) waters containing dissolved silica (Si(OH)4), Ca2 +  and Mg2 + . The removal of each target species was measured as a function of the coagulant dose in simulated CTB waters with initial pH values of 5, 7, and 9. Experiments were also performed to investigate the effect of antiscaling compounds and coagulation aids on hardness ion removal. Both iron and aluminum electrodes were effective at removing dissolved silica. For coagulant doses ≤3 mM, silica removal was a linear function of the coagulant dose, with 0.4 to 0.5 moles of silica removed per mole of iron or aluminium. Iron electrodes were only 30% as effective at removing Ca2 +  and Mg2 +  as compared to silica. There was no measurable removal of hardness ions by aluminium electrodes in the absence of organic additives. Phosphonate based antiscaling compounds were uniformly effective at increasing the removal of Ca2 +  and Mg2 +  by both iron and aluminium electrodes. Cationic and amphoteric polymers used as coagulation aids were also effective at increasing hardness ion removal.


2021 ◽  
Vol 8 ◽  
Author(s):  
Analía Rodríguez ◽  
Patricia Lema ◽  
María Inés Bessio ◽  
Guillermo Moyna ◽  
Cristina Olivaro ◽  
...  

The effect on color of the initial pH employed in dulce de leche (DL) production was evaluated through physicochemical and spectroscopical characterization of the melanoidins formed in the process. Melanoidins originated at pH values of 6.5, 7.0, and 7.5, and they were released by the enzymatic hydrolysis of the protein backbone and purified by gel filtration. They showed a significant degree of polydispersity, in general, with molecular weights (MWs) below 1,800 Da. DL produced at a higher pH released melanoidins with higher average MW after the enzymatic hydrolysis. They also presented darker colors (dE*ab, C*), more closely resembling those typical of the commercial product. Analysis of the fractions isolated by gel filtration using HPLC-DAD and multinuclear NMR showed an heterogeneous and complex composition. Even though structurally related, the 1H NMR spectra of melanoidins showed a higher degree of aromaticity at higher pH values. In conclusion, the pH employed in DL production affects the amount and structure of the colored products originated by MR reactions, and thus the color of the final product.


Author(s):  
Ang Li ◽  
Jun Chen ◽  
Yangfan Liu ◽  
Stuart Bolton ◽  
Patricia Davies

Abstract In recent years, the bladeless fan that does not have visible impellers have been widely applied in household appliances. Since the customers are particularly sensitive to noise and the strength of wind generated by the fan, the aerodynamic and acoustic performances of the fan need to be accurately characterized in the design stage. In this study, computational fluid dynamic (CFD) and computational aeroacoustics (CAA) are applied to investigate the performances of different designs of a bladeless fan model. The influence of four parameters, namely the airfoil selection for cross-section of the wind channel, the slit width, the height of cross-section and the location of the slit, is investigated. The results indicate the streamwise air velocity increases significantly by narrowing the outlet, but the noise level increases simultaneously. In addition, the generated noise increases while the height of fan cross-section increases, and a 4mm height of the cross section is optimal for aerodynamic performance. When the slit is closer to the location of maximum thickness, the performances of the bladeless fan increases. Moreover, the performance is not changed significantly by changing the cross-sectional profile. Finally, the optimal geometric parameters are identified to guide the future design of the bladeless fan.


2013 ◽  
Vol 85 (6) ◽  
pp. 863-871 ◽  
Author(s):  
Thomas G. Palmen ◽  
Marco Scheidle ◽  
Robert Huber ◽  
Claudia Kamerke ◽  
Anja Wilming ◽  
...  
Keyword(s):  

1993 ◽  
Vol 58 (5) ◽  
pp. 1093-1102 ◽  
Author(s):  
Aleksandra A. Mitrovic ◽  
Slobodan K. Milonjic ◽  
Zoja E. Ilic ◽  
Radomir V. Stevanovic

The influence of hydroxide ions concentration of the aqueous sodium hydroxide solution, at constant sodium concentrations, on the gallium extraction with Kelex 100 was examined in the hydroxide concentration range from 0.02 to 0.5 mol dm-3. The percentage of extracted gallium increases from 51% to 98% within the investigated hydroxide concentration range. The influence of sodium concentrations (from 1 to 6 mol dm-3) on the gallium extraction was also studied at constant pH values. The decrease of extracted gallium is slight for the sodium concentration up to 3 mol dm-3, while for the higher ones it is pronounced. The extraction kinetics was studied using a mixer-type apparatus. The rate expression of the extraction reaction of gallium with Kellex 100, for both lower and higher hydroxide concentrations are ascertained.


1993 ◽  
Vol 71 (12) ◽  
pp. 1584-1588 ◽  
Author(s):  
Craig S. Smith

A bicarbonate-buffered hard-water medium was evaluated for the solution (nonrooted) culture of submersed aquatic plants. The new medium had an initial pH of 8.2, and after 2 weeks of plant growth in it, pH values remained similar to those in hard-water lakes. Several plants from hard-water lakes grew more rapidly in the new medium than in the commonly used Gerloff medium. When cultures were aerated with air, Myriophyllum spicatum growth was nearly twice as great in the new medium as in Gerloff medium, and growth of Vallisneria americana and Elodea canadensis in the new medium was 4 and 13 times that in Gerloff medium, respectively. When both cultures were aerated with 1% CO2, growth rates of M. spicatum and E. canadensis in the new medium were not distinguishable from those in Gerloff medium, but the growth of V. americana was 40% greater in the new medium. Myriophyllum spicatum was much less susceptible to attack by the fungal pathogen Colletotrichum gloeosporioides in the new medium than in Gerloff medium, similar to the susceptibility shown in nutrient-amended lake water. Key words: aquatic plants, culture techniques, plant pathogens.


1987 ◽  
Vol 50 (10) ◽  
pp. 872-875 ◽  
Author(s):  
ESPERANZA GOMEZ-LUCIA ◽  
JOAQUIN GOYACHE ◽  
JOSE L. BLANCO ◽  
JOSE F. F. GARAYZABAL ◽  
JOSE A. ORDEN ◽  
...  

The ability of Staphylococcus aureus to grow and produce enterotoxins in homemade mayonnaise prepared at different pH values was studied. Ten enterotoxigenic strains, producing one or two enterotoxin types (A, B, C, or D) were inoculated into mayonnaise samples with pH adjusted to values ranging between 4.0 and 5.8, and incubated at 37°C for 7 d. Counts were made on days 1, 3, 5, and 7 and extracts were prepared on day 7 to detect enterotoxin by ELISA. An important difference was seen between those samples prepared with pH below or equal to 4.9 and those over or equal to 5.0; in the range of pH between 4.0 and 4.9 the average of staphylococcal population was 100 CFU/g; at pH 5.0 it was 1.6 × 105, and at pH 5.15 and above it was at least 8 × 106 CFU/g. Enterotoxin was detected only at initial pH over 5.15 and when final pH was not less than 4.7. The highest amount of enterotoxin corresponded to 157.8 ng of SEB/100 g of mayonnaise.


1994 ◽  
Vol 57 (3) ◽  
pp. 259-262 ◽  
Author(s):  
RIITTA MAIJALA

The preservative effect of fermentation is based on the pH decrease during processing. However, most studies conceming the influence of pH on the formation of biogenic amines have been made in broths with different initial pH values. A histamine- and tyramine-positive Lactobacillus strain isolated from dry sausage was added at an initial level of 3.9- to 4.4-logl0 CFU/ml and incubated on a shaker at room temperature (20.0°C) for 6 days. The pH was decreased in histidine- or tyrosine-fortified MRS broth by adding glucono-delta-lactone (GDL) or lactic acid during the incubation. The external acidification decreased the growth and the production of histamine and tyramine by the strain. GDL was more effective as a preventative than lactic acid. According to these results, a rapid pH decrease resulting in decreased growth of amine-positive lactic acid bacteria in the beginning of fermentation may be a means of preventing the formation of high levels of amines in foods.


2002 ◽  
Vol 69 (1) ◽  
pp. 125-137 ◽  
Author(s):  
MIGUEL GUEIMONDE ◽  
NIEVES CORZO ◽  
GABRIEL VINDEROLA ◽  
JORGE REINHEIMER ◽  
CLARA G. DE LOS REYES-GAVILÁN

The influence of carbonation on the evolution of lactose, galactose and glucose in fermented milks with added probiotic bacteria (Lactobacillus casei, Lactobacillus acidophilus and/or Bifidobacterium bifidum) was evaluated and related to β-galactosidase activity of starter strains. During incubation and first days of refrigeration, lactose hydrolysis resulting in the liberation of galactose and glucose occurred in CT (Streptococcus thermophilus/Lb. casei), AT (Str. thermophilus/Lb. acidophilus) and ABT fermented milks (Str. thermophilus/Lb. acidophilus/Bifid. bifidum). Levels of galactose were higher than those of glucose and could be related to the preferential consumption of glucose by actively growing bacteria. Through the incubation, lactose and monosaccharide levels were not affected by milk carbonation. However, during refrigerated storage the presence of this gas was associated with slightly lower content of lactose and higher levels of galactose and glucose in AT and ABT products but not in CT fermented milks. Through the refrigeration galactose was moderately utilised by Lb. acidophilus in AT products whereas the presence of Bifid. bifidum seems to prevent the consumption of this sugar in ABT fermented milks. Glucose remained constant, with minor variations in CT products but a continuous increase of this sugar occurred in carbonated AT and ABT fermented milks during storage. β-Galactosidase activity displayed by Str. thermophilus strains was similar at pH 6·5 (initial pH of non-carbonated samples) and pH 6·3 (initial pH of carbonated samples) whereas Lb. acidophilus LaA3 showed greater β-galactosidase activity at pH 6·3 than at higher pH values. Thus, the enhanced metabolic activity of Lb. acidophilus caused by the low initial pH of carbonated milk also promoted higher cellular β-galactosidase activity that could have released greater amounts of galactose and glucose from lactose in AT and ABT fermented milks through the refrigerated period. In CT fermented milks, similar β-galactosidase activity levels of Str. thermophilus at pH 6·5 and 6·3 together with the absence of β-galactosidase activity in Lb. casei could explain the lack of differences on glucose and galactose content between carbonated and non-carbonated samples.


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