摘要:

A number of samples of commercially available spray‐dried and roller‐dried caseinates have been compared with freshly prepared caseinate from the laboratory. The compositions of the materials were measured using chromatography, and their calcium susceptibilities were determined using turbidity measurements. The chromatographic analysis showed that the commercial caseinates differed substantially from the fresh material, especially in the regions where α‐casein and αs2‐caseins were eluted. The fresh caseinate was more affected by the presence of calcium ions than the others, and there were also differences between the individual spray‐dried caseinates in this respect. The roller‐dried caseinates were very insensitive to the presence of

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00571.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The influence of detergent concentration, temperature and flow rate on the time to remove milk deposits from the heated surfaces of a plate heat exchanger was studied. The results indicate that the main reduction in cleaning time was produced by small increases in the passage mean velocity of flow in the range 0.2 to 0.5 m/s. Increasing the temperature to 75 °C also resulted in substantial reductions in cleaning time. Variations in concentration, for which there was an optimum, had the least effect on cleaning time of the parameters investigated

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00572.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00573.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Milk samples from all quarters of 13 dairy cows, each treated with an antibiotic preparation for clinical mastitis in one quarter, were collected at each milking during treatment and for at least six milkings thereafter. After storage at —25 °C, these were tested for the presence of antibiotics. Transfer to untreated quarters was found in eight of the 13 cases studied, although in only two cases was the level in untreated quarters greater than 0.01 μ/ml. The main factor affecting transfer was found to be a history of infection in the treated quarter. This was observed in all but one case where transfer had occurred. During the period of study incorporation of milk from untreated quarters would not have raised the antibiotic level in the bulk supply to a level which would have incurred a financial pena

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00574.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The fate of radioactive contamination resulting from fallout from the Chernobyl accident was studied during milk processing. A range of commercial dairy products was produced on a pilot/laboratory scale and the radiocaesium contents were measured by high‐resolution gamma spectrometry. The results show that the radiocaesium partitioned with the water phase and therefore butter, cream and cheese had relatively low levels of radioactivity. Ion exchange demineralization was effective in removing radiocaesium from whey. Ultrafiltration of whey resulted in a reduction of radioactivity relative to retentate solid

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00575.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The effect of volume and temperature of pre‐rinse water on the cleaning efficiency of five circulation cleaned recorder milking machines was investigated. A hot (>75 °C) pre‐rinse gave the lowest bacteriological rinse total colony counts. As the rinse count differences were small, the least expensive cold water pre‐rinse is considered satisfactory for most farms. A pre‐rinse volume of 16 litres per unit removed more residual milk than eight litres per unit but gave no significant difference in rinse counts. For most plants 8–10 litres per unit is considered a satisfactory pre

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00576.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00577.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Skim milk and mixtures prepared by combining acid whey with skim milk at volume ratios of 2:1, 1:1, 1:2, 1:3 and 1:4 were adjusted to pH 7.5 and heated at 90°C × 15 min. Protein was isolated from these heated samples by precipitation at pH 4.6 and it was found that 65% of the whey protein was recovered in each case. Non‐recovered proteins included the proteose peptones and small quantities of β‐lactoglobulin, α‐lactalbumin and bovine serum albumin. The solubility of these isolates, which contained from 10–25% whey protein, decreased to>95% when the whey protein exceeded ˜16%. Further characterization of the isolate, prepared from the 1:1 volume ratio of acid whey and skim milk, showed that ˜50% of the whey protein was insoluble, bound to casein and non‐functional while the other ˜50% was complexed with casein and was soluble. The addition of a reducing agent suggests that sulphydryl bonding alone is not responsible for c

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00578.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00579.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1988.tb00580.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY