Microbiological Conditions and Keeping Quality of Veal Tongues as Affected by Lactic Acid Decontamination and Vacuum Packaging

1988 ◽  
Vol 51 (3) ◽  
pp. 208-213 ◽  
Author(s):  
INGRID J. R. VISSER ◽  
PETER A. KOOLMEES ◽  
PETER G. H. BIJKER
Keyword(s):  
Lactic Acid ◽  
Tap Water ◽  
Treated Group ◽  
Vacuum Packaging ◽  
Delayed Effect ◽  
Veal Calf ◽  
Keeping Quality ◽  
Stratified Squamous Epithelium ◽  
Ice Water

The effect of a lactic acid decontamination treatment on the microbiological condition and keeping quality of veal calf tongues was assessed. Thirty tongues were collected 45 min post mortem. Ten were washed with tap water in a centrifuge, 10 were treated with 2.0% (v/v) L-lactic acid instead of water, and 10 tongues received no treatment and served as control samples. Immediately following these treatments all tongues were vacuum-packaged, chilled 2 h in ice-water and stored at 3±1 °C and 85±5 % ERH. At 0, 14, and 28 d postmortem samples were taken for bacteriological, histobacterioscopic and sensory examination. The histobacterioscopic examination showed that the initial microflora appeared to be predominantly located under and between the papillae of the tongue surface. Centrifugation with water only did not significantly affect the bacteriological condition of tongues, although the overall appearance improved. Decontamination with lactic acid decreased mesophilic aerobic colony counts from 5.6 to 2.7 log10 CFU/cm2. After 14 d of storage the so-called “delayed” effect of lactic acid was still observed. At that time aerobic colony counts and Enterobacteriaceae counts of controls were 6.5 and 2.8 log10 CFU/cm2, while these counts of the lactic acid treated group were 4.0 and <1.3, respectively. Results of the bacteriological examinations were substantiated by the histobacterioscopic findings. Centrifugation with lactic acid detached superficial cells from the stratified squamous epithelium. Decontamination of tongues by centrifugation with lactic acid before vacuum packaging will increase storage life and safeguard public health.

693. A rejection test for raw milk

1958 ◽  
Vol 25 (1) ◽  
pp. 32-51 ◽  
Author(s):  
Peggy B. Taylor ◽  
L. F. L. Clegg
Keyword(s):  
Lactic Acid ◽  
Ferric Chloride ◽  
Technical Assistance ◽  
Milk Proteins ◽  
Raw Milk ◽  
Ph Change ◽  
Yellow Colour ◽  
A Value ◽  
Keeping Quality

The determination of apparent lactic acid has been used as a basis for a rejection test for raw milk. The method consists of precipitation of milk proteins with barium chloride, sodium hydroxide and zinc sulphate, and the addition of ferric chloride to the filtrate to produce the yellow colour of ferric lactate. Lactic acid is not solely responsible for the production of the yellow colour, which, nevertheless, gives a good relationship with keeping quality of milk (measured as hours to the C.O.B. end-point at 22° C.) and the values have been expressed as ‘apparent lactic acid’.The relationship of winter and summer milks to keeping quality has been studied, and a value of 0·03% apparent lactic acid in milk is equivalent to an average keeping quality of 5¾ and 8½ hr. for winter and summer milks, respectively. A value of 0·03% is recommended as the earliest value of apparent lactic acid at which milk could be rejected.The apparent lactic acid in colostrum and late-lactation milk and in milk from cows suffering from mastitis has been determined, and only in late-lactation milk were the values found to be significantly higher than usual in fresh raw milk, and an inverse relationship between yield and apparent lactic acid is suggested.Permanent glass matching disks have been prepared for use in a Lovibond comparator. This permits the intensity of the yellow colour produced with 1% ferric chloride to be determined and the apparent lactic acid in milk estimated.Grateful acknowledgement is made to the management and staff of the Dairy Department of the Reading Co-operative Society and the Farmer's Clean Milk Dairy, Reading, and local milk producers for supplying samples for experiments; to the N.M.T.S. staff in Reading for help in finding suitable farmers, and to the Dairy Husbandry Department of the N.I.R.D. for information about and samples of abnormal and late-lactation milk. Our particular thanks are due Miss Marie Gruber for technical assistance, to Dr N. J. Berridge for the suggestion and help on the work on pH change as an indication of keeping quality (given in the appendix), and to Dr A. T. R. Mattick for the advice given in this work.

Studies on the manufacture of sweet cream starter butter: II. Effect of variation in proportion of starter added to cream

1960 ◽  
Vol 27 (1) ◽  
pp. 91-102 ◽  
Author(s):  
F. H. McDowall ◽  
J. A. Singleton ◽  
B. S. Le Heron
Keyword(s):  
Lactic Acid ◽  
Low Temperatures ◽  
Starter Culture ◽  
Skim Milk ◽  
Ph Values ◽  
Commercial Scale ◽  
Increase With Increase ◽  
Keeping Quality ◽  
Higher Temperature

SummaryProduction of diacetyl and acetoin by starters in cold skim-milk and cream was shown to increase with increase in the proportion of starter culture added, with some limitations at the higher rates of starter addition.With Streptococcus diacetilactis starter in skim-milk at 50°F the relation between proportion of starter added and production of diacetyl was linear up to addition at the 4% level, whereas at 43°F it was approximately linear up to the 10% level. At both 50 and 43°F the relation between the proportion of starter added and the production of acetoin was linear up to the 10% level.With Camb starter in skim-milk at both 50 and 43°F there were regular increases in production of diacetyl up to the 4% level of addition, but only minor changes thereafter with increase in the proportion of starter added up to 10%. At both temperatures the maximum production of acetoin was reached with the 7% rate of addition.Production of diacetyl and acetoin in skim-milk was greater at 50°F than at 43°F with both starters for all proportions up to 10%, and it was greater for Str. diacetilactis than for the mixed cultures.Except at the higher rates of addition of starter and at the higher temperature there were no concomitant increases in the acidity of the milk or lowering of the pH values. It appears that at low temperatures production of diacetyl by starters in sweet milk and cream proceeds independently of production of lactic acid.Similar results were obtained in a series of experimental buttermaking trials and some small commercial-scale trials, in which varying proportions of starter were added to creams after pasteurizing and before holding overnight for churning. With the cream-holding temperatures used, mainly 40–50°F, the pH values of the butters were not appreciably lowered by the starter additions to the cream. At all the rates of addition there were with Str. diacetilactis starter higher contents of diacetyl in the butter than with Camb starter. There was no indication of any relationship between the proportion of starter added and the keeping quality of the butter.

scholarly journals Study on the Extension of Shelf-life by Activation of Inherent Lactoperoxidase System in Raw Cow Milk

2014 ◽  
Vol 7 ◽  
pp. 57-60
Author(s):  
Prashanta Pokhrel ◽  
Suman Kumar Lal Das
Keyword(s):  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Shelf Life ◽  
Room Temperature ◽  
Raw Milk ◽  
Potassium Thiocyanate ◽  
Cow Milk ◽  
Lactoperoxidase System ◽  
Keeping Quality

Effectiveness of lactoperoxidase in raw cow milk was studied to observe the increase in shelf-life. Lactoperoxidase system was activated within two hours after milking by the addition of hydrogen peroxide and potassium thiocyanate, then milk was kept at different conditions viz. refrigerated condition (5±2)°C, room temperature (25±3)°C and at (35±2)°C. The keeping quality of raw milk was determined by the acidity, which when reached 0.18 % as lactic acid, was considered spoiled. Results indicated that the lactoperoxidase system (LP-s) increased the shelf-life of raw cow milk kept at room temperature (25±3)°C and refrigeration temperature (5±2)°C significantly (p<0.05);however no significant increase in shelf-life was observed between the control and LP-s treated raw milk sample held at (35±2)°C. DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10606   J. Food Sci. Technol. Nepal, Vol. 7 (57-60), 2012   

Effectiveness of Benzoic Acid Ice for Fish Preservation

1939 ◽  
Vol 4b (5) ◽  
pp. 327-336 ◽  
Author(s):  
H. L. A. Tarr ◽  
B. E. Bailey
Keyword(s):  
Benzoic Acid ◽  
Bacterial Population ◽  
Tap Water ◽  
Anoplopoma Fimbria ◽  
Water Ice ◽  
Relative Age ◽  
Keeping Quality ◽  
Crushed Ice

Only a very slight improvement in keeping quality of dressed halibut (Hippoglossus hippoglossus) and black cod (Anoplopoma fimbria), as evidenced by differences in viable bacterial population and trimethylamine content of excised muscle, results when the fish are stored in crushed tap water ice containing 0.1 per cent benzoic acid instead of in similar ice without this compound. The methods employed for a relatively simple determination of both viable bacterial population and trimethylamine content of the same sample of muscle are described, and the limitations of these as criteria of the relative age of dressed fish stowed in crushed ice are discussed. The "tyrosine" reaction failed to show greater effectiveness for benzoic acid ice; the values increased during storage, but were too irregular to serve as a safe criterion of spoilage.

Immediate and Delayed Microbiological Effects of Lactic Acid Decontamination of Calf Carcasses - Influence on Conventionally Boned Versus Hot-Boned and Vacuum-Packaged Cuts

1985 ◽  
Vol 48 (10) ◽  
pp. 838-847 ◽  
Author(s):  
FRANS J. M. SMULDERS ◽  
CASPAR H. J. WOOLTHUIS
Keyword(s):  
Lactic Acid ◽  
Acid Treatment ◽  
Limit Of Detection ◽  
Additional Treatment ◽  
Vacuum Packaging ◽  
Delayed Effect ◽  
Treatment Groups ◽  
Slaughter House ◽  
Yeasts And Molds ◽  
Made In

Three experiments involving a total of 114 calves were done. The first two experiments, conducted under simulated export conditions, monitored the immediate and delayed microbiological effects of decontamination with 1.25% (vol/vol) L-lactic acid on calf carcasses as well as the effects of an additional treatment with 2.00% (vol/vol) L-lactic acid and vacuum-packaging on hot-boned veal cuts. In a third experiment, data from these investigations were tested under actual export conditions and were found to be similar. As a result of 1.25% (vol/vol) L-lactic acid treatment, aerobic colony counts (3 d at 30°C and 5 d at 17°C) were reduced by 0.8 log10 CFU as compared with initial counts of approximately 3.0 log10 CFU/cm2 on control carcasses. However, the reduction increased to 1.3 log10 CFU at 14 d postmortem, indicating some delayed effect of lactic acid. The percentage of samples positive for Enterobacteriaceae was reduced from 50% to approximately 10% which corresponded with a mean reduction of 0.3 log10 CFU/cm2. Vacuum-packaging virtually completely inhibited growth of bacteria, yeasts and molds on hot-boned cuts, but 1 wk after breaking the counts reached values similar to controls. When measured 7 d postmortem, lactic acid treatment combined with vacuum-packaging was significantly more effective in reducing aerobic colony counts than vacuum-packaging alone. At 14 d postmortem, this was still the case for cuts that had been subjected to an additional decontamination with 2.00% (vol/vol) L-lactic acid immediately before vacuum-packaging. The Enterobacteriaceae colony count of hot-boned vacuum-packaged cuts remained under its limit of detection of 1.3 log10 CFU as a result of lactic acid decontamination. Lactobacillaceae colony counts were extremely low in all treatment groups. No salmonellae were isolated from any sample, indicating that marked progress has been made in controlling Salmonella contamination of veal in The Netherlands. This was accomplished by having separate fattening and slaughter lines and markedly improving slaughter house practices.

Effect of ripening cream with selected lactic acid bacteria on the quality of ghee

1980 ◽  
Vol 47 (3) ◽  
pp. 411-415 ◽  
Author(s):  
Abraham M. Joseph ◽  
Srinivasan R. Appachar
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Titratable Acidity ◽  
Maximum Amount ◽  
Lactobacillus Bulgaricus ◽  
Streptococcus Lactis ◽  
Keeping Quality ◽  
Indian Product

SummaryThe effect of ripening cow'milk cream (40% fat) with 4 strains of lactic acid bacteria on the quality of ghee, an Indian product resembling clarified butterfat, was studied by measuring changes in titratable acidity, pH, volatile acids and diacetyl content due toStreptococcus lactis, Str. lactissubsp.diacetylactis (Str. diacetylactis), Str. thermophilusandLactobacillus bulgaricusin cream prior to conversion into ghee.L. bulgaricusproduced the maximum titratable acidity (1·25% lactic acid) followed byStr. diacetylactis(0·80 % lactic acid) after 72 h.Str. diacetylactisproduced the highest level of diacetyl (28 ppm), after 48 h.L. bulgaricusproduced no detectable diacetyl. Both of these strains produced the maximum amount of volatile acids (2·2–3·5 ml), after 72 h. The flavour and keeping quality of ghee were improved byStr. diacetylactisandStr. lactiswhilstStr. thermophilusandL. bulgaricushad no effect.

scholarly journals Hardening Properties of Cheeses by Latilactobacillus curvatus PD1 Isolated from Hardened Cheese-Ddukbokki Rice Cake

2021 ◽  
Vol 9 (5) ◽  
pp. 1044
Author(s):  
Jeong A Kim ◽  
Geun Su Kim ◽  
Se Mi Choi ◽  
Myeong Seon Kim ◽  
Do Young Kwon ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Production ◽  
Lactobacillus Casei ◽  
Leuconostoc Mesenteroides ◽  
The Other ◽  
Rice Cake ◽  
Two Samples ◽  
High Protease Activity

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacillus curvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.

scholarly journals Tap Water Quality: Seasonal User Surveys in Poland

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3841
Author(s):  
Józef Ober ◽  
Janusz Karwot
Keyword(s):  
Water Quality ◽  
World Literature ◽  
Mixed Methods Research ◽  
Tap Water ◽  
Quality Parameters ◽  
Subjective Perception ◽  
Quality Of Water ◽  
Profit Analysis ◽  
Tap Water Quality

Security of supply of water, which meets the quality parameters specified in applicable standards, is now the basis for the functioning of most societies. In addition to climatic, biological, chemical, and physical hazards, it is worth paying attention to consumers’ subjective perception of the quality of tap water supplied in the area of Poland. The article discusses various activities related to water resources management and analyses the results of an evaluation of selected quality parameters of tap water in Poland. A novelty on a European scale here is an examination of the evaluation of these parameters based on potential seasonal differences (spring, summer, autumn, winter). For the first time in the world literature, PROFIT analysis was used to evaluate selected parameters of tap water quality. The aim of the article was to present a model for the evaluation of the parameters of tap water supplied in different seasons of the year in Poland. Due to the complexity of the research aspects, a mixed-methods research procedure was used in which a literature review was combined with a survey and statistical analysis. For the purpose of the survey, an original survey questionnaire called “Survey of customer opinions on selected parameters of tap water supplied in Poland” was developed especially for this study. The conducted research confirmed the adopted hypothesis that the results of evaluation of selected tap water parameters vary depending on the period (spring, summer, autumn, winter) in Poland. The model developed by means of PROFIT analysis makes it possible to highlight to water suppliers the specific quality parameters in particular seasons of the year (spring, summer, autumn, winter), which may improve the quality of water supplied in Poland and thus, in the long-term perspective, increase the level of satisfaction of water recipients and confidence in drinking tap water in Poland.

Keeping Quality of Pacific Coast Dogfish

1959 ◽  
Vol 16 (6) ◽  
pp. 791-794 ◽  
Author(s):  
R. H. Moyer ◽  
B. A. Southcott ◽  
E. G. Baker ◽  
H. L. A. Tarr
Keyword(s):  
Pacific Coast ◽  
Sea Water ◽  
Total Volatile ◽  
Bacterial Counts ◽  
Ph Values ◽  
Appreciable Increase ◽  
Muscle Ph ◽  
Keeping Quality ◽  
Viable Bacteria

Pacific coast dogfish (Squalus suckleyi) were held 21 days in ice and in refrigerated sea water with and without added chlortetracycline, viable bacterial counts and volatile bases being determined periodically. Viable bacteria increased sharply after about 14 days but the muscle pH values showed little or no increase. No appreciable increase in the total volatile base or trimethylamine content of the muscle was noted until the fish were stored for more than 2 weeks, and then the increases observed were comparatively small.

Sign in / Sign up

Export Citation Format

Share Document