摘要:

Seven hundred and fifty‐four bulk milk samples from a total of 9,066 tested by the Aberdeen and District Milk Marketing Board in 1984 had total bacterial counts greater than 45,000 per ml. Of the failed samples, 43.8% had more mastitis‐related bacteria present than non‐mastitis types. More than a quarter of the failed samples had almost pure cultures ofStreptococcus agalactiae, Str. dysgalactiae, Str. uberis, Staphylococcus aureusor coagulase‐negative staphylococci. No relation was found between the failed samples resulting from subclinical mastitis infections and the somatic cell count of the bulk milk. Seventy‐five per cent of the financial penalties imposed on producers were attributable to mastitis bacteria in bulk mil

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02829.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Since the introduction by Milk Marketing Boards throughout the UK of automated systems which enable total bacterial counts to be carried out economically and at frequent intervals on bulk milk consignments, streptococci associated with subclinical mastitis are more readily detected. In many cases the presence of these organisms has resulted in heavy financial penalties being imposed. We describe an improved selective medium which could assist in the rapid detection of such cases and allow prompt remedial action to be taken.

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02830.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The Penzym assay is a rapid enzymic method for the detection of β‐lactam antibiotics in milk in 20 minutes. Two collaborative trials of the Penzym assay were conducted between 11 laboratories using raw whole milk samples containing levels of 0.005 iu/ml, 0.015 iu/ml and 0.025 iu/ml penicillin G and were tested at 0.01 iu/ml and 0.02 iu/ml pass/fail levels. Trial 1 indicated a degree of operator dependency with a tendency to give false passes. Trial 2 confirmed the operator dependency, and both false passes and false failures were obtained. These results make the test unacceptable as a rejection test for detecting β‐lactam antibiotics in dairy laboratories. However, given the speed of testing and level of accuracy (92%), the assay may still be valuable as a screening

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02831.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Stack losses from a full‐scale skimmed milk drying plant were measured continuously using a new instrument designed for this purpose. The performance of this continuous monitor was compared to the universally adopted method of isokinetic sampling. Based on a total of 29 measurements, a close correlation was established between the two techniques. Stack losses reached a maximum during start‐up and shut‐down of the dryer. Fluctuations in the total solids content of the concentrate feed from the evaporator seemed to affect stack loss variation during a processin

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02832.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

A survey was carried out to assess the nutritional composition of infant formulae currently available in the UK. Eleven products were analysed for major constituents, gross energy, minerals and amino acids. Results were compared with manufacturers' data and also with existing UK compositional guidelines. Analytical values for all constituents were in good agreement with manufacturers' data and generally within the recommended guidelines. The chloride content of one product was found to be marginally below the minimum guideline and not in accord with the labelled value. An investigation into methodology in collaboration with the manufacturer revealed a marked difference in results (∼10%) according to the choice of method. This difference accounts for the discrepancy between the survey and labelled value

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02833.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The An Bord Bainne method, the Australian Standard method and an automatic electromagnetic method for determining the heat‐coagulation time of 20% skimmed milk powder solutions have been examined for accuracy and comparability of the results, based on 50 samples. Nine representative samples were chosen from the classes ‘non‐heat‐stable’, ‘moderately heat‐stable’, and ‘highly heat‐stable’ and used for evaluating the standard deviation and the coefficient of variation of the respective procedures. The statistic correlation between the measured values was carried out by means of Spearman's coefficient of rank correlation (rs), whereby the calculation was done not only for all the 50 milk powder samples but additionally also for 14 samples classified as ‘highly heat‐stable’. In both cases the correlation was significan

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02834.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

There are basically two methods by which the manufacture of cheese from milk concentrated by ultrafiltration can increase yields. Firstly, the procedure can increase the weight of certain water‐soluble, solids‐non‐fat components (mainly whey proteins) in the cheese. This extra solids‐non‐fat may allow extra water to be incorporated into the product without a decline in quality. Secondly, if suitable equipment can be designed, manufacture of cheese from concentrated milk can lead to a reduction in the losses of insoluble casein, fat and fines. The present study suggests that with a fivefold concentration of milk by ultrafiltration, and with the same losses of insoluble casein, fat and fines as with conventional cheesemaking, the yield of Cheddar is increased by around 4.5%. About half this increase is due to water‐soluble, solids‐non‐fat components; the remainder is due to water. With the elimination of all losses of insoluble casein and fines the gain in product is predicted to be around 6% while increases in the fat retention to 95% would bring the yield advantage to about 8%. However, it is suggested that the elimination of casein fines losses may be difficult to achieve in commercial‐scale, ultrafiltration cheesemaking equipment and that reductions in fat percentages in the whey are of little financial advantage to companies that

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02835.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Book reviewed in this article:Water supply byelaws guide. Edited by S F White&G D Mays.

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02836.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1987.tb02837.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY