Pub Date : 1976-12-01DOI: 10.4315/0022-2747-39.12.864
M. J. Taylor, T. Richardson, N. Olson
Enzymatic coagulation of milk by immobilized proteases, and their potential application to cheese manufacture, is reviewed. Particular emphasis is given to the immobilized protease catalyst and to the reactor design for coagulation of milk. Pepsin and chymotrypsin retained more activity and greater stability than the other immobilized proteolytic enzymes. Porous glass beads, several anion exchange resins, and the copolymer ethylene-maleic anhydride gave best results among the support materials that were evaluated. Covalent attachment of enzyme to support is preferable to adsorption techniques but may be too costly. Perhaps the best catalyst is one using a lengthy procedure for covalent immobilization of enzyme on glass beads but good results were also obtained with simpler adsorption techniques. Catalysts varied greatly in initial activity but all lost activity upon exposure to milk. Stirred tank, packed bed, and fluidized bed reactor designs were used. Continued research is required to make enzymic milk ...
{"title":"Coagulation of Milk with Immobilized Proteases: A Review","authors":"M. J. Taylor, T. Richardson, N. Olson","doi":"10.4315/0022-2747-39.12.864","DOIUrl":"https://doi.org/10.4315/0022-2747-39.12.864","url":null,"abstract":"Enzymatic coagulation of milk by immobilized proteases, and their potential application to cheese manufacture, is reviewed. Particular emphasis is given to the immobilized protease catalyst and to the reactor design for coagulation of milk. Pepsin and chymotrypsin retained more activity and greater stability than the other immobilized proteolytic enzymes. Porous glass beads, several anion exchange resins, and the copolymer ethylene-maleic anhydride gave best results among the support materials that were evaluated. Covalent attachment of enzyme to support is preferable to adsorption techniques but may be too costly. Perhaps the best catalyst is one using a lengthy procedure for covalent immobilization of enzyme on glass beads but good results were also obtained with simpler adsorption techniques. Catalysts varied greatly in initial activity but all lost activity upon exposure to milk. Stirred tank, packed bed, and fluidized bed reactor designs were used. Continued research is required to make enzymic milk ...","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"100 1","pages":"864-871"},"PeriodicalIF":0.0,"publicationDate":"1976-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85392611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1976-08-01DOI: 10.4315/0022-2747-39.8.546
C. J. Washam, W. Sandine, P. R. Elliker
{"title":"A Strain of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound: III. Electron Microscopy","authors":"C. J. Washam, W. Sandine, P. R. Elliker","doi":"10.4315/0022-2747-39.8.546","DOIUrl":"https://doi.org/10.4315/0022-2747-39.8.546","url":null,"abstract":"","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"71 1","pages":"546-550"},"PeriodicalIF":0.0,"publicationDate":"1976-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73638459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1976-04-01DOI: 10.4315/0022-2747-39.4.246
L. Weckbach, B. E. Langlois
Three hundred and three isolates obtained from plating bovine foremilk samples on Baird-Parker Agar were grouped using numerical taxonomy. Clustering of the isolates according to their percent similarity resulted in 19 groups; of these, eight groups contained over nine members. The other 11 groups contained 38 isolates. All 19 groups were joined at the 75% similarity level, with 17 of the groups being joined above the 85% similarity level. Results indicate that all but 16 of the isolates belonged to the same genus (Staphylococcus). and they probably belonged to one species (Staphylococcus aureus) or at least to closely related species. All but 17 isolates were catalase-positive. The greatest variations among the groups were in utilization of carbohydrates, chromogenesis, gelatinase production. and growth at 0 and 7 C and in 15% salt.
{"title":"Classification by Numerical Taxonomy of Staphylococci Isolated From the Bovine Udder","authors":"L. Weckbach, B. E. Langlois","doi":"10.4315/0022-2747-39.4.246","DOIUrl":"https://doi.org/10.4315/0022-2747-39.4.246","url":null,"abstract":"Three hundred and three isolates obtained from plating bovine foremilk samples on Baird-Parker Agar were grouped using numerical taxonomy. Clustering of the isolates according to their percent similarity resulted in 19 groups; of these, eight groups contained over nine members. The other 11 groups contained 38 isolates. All 19 groups were joined at the 75% similarity level, with 17 of the groups being joined above the 85% similarity level. Results indicate that all but 16 of the isolates belonged to the same genus (Staphylococcus). and they probably belonged to one species (Staphylococcus aureus) or at least to closely related species. All but 17 isolates were catalase-positive. The greatest variations among the groups were in utilization of carbohydrates, chromogenesis, gelatinase production. and growth at 0 and 7 C and in 15% salt.","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"11 1","pages":"246-249"},"PeriodicalIF":0.0,"publicationDate":"1976-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84882741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1976-04-01DOI: 10.4315/0022-2747-39.4.297
J. B. Robinson
Elements such as nitrogen, carbon, phosphorus, and sulfur occur in the biosphere in a variety of chemical forms, each subject to biological or spontaneous conversion to other forms. In natural ecosystems such as grasslands and forests, these “cycles” operate very efficiently. The cycling of nitrogen in grassland is used to illustrate the conservative nature of natural systems. Food production, practiced on an extensive basis with minimum inputs and careful management may have minimum disruptive effects on local geochemical cycles, particularly if food is processed and consumed locally. Intensive agriculture, with its large energy inputs, and high yields, accompanied by extreme urbanization and remote food processing, induces major changes in local cycling. The localized effects of food production and processing have become a problem in industrialized countries which too often depend on food production, processing, and waste-treatment systems developed when the degree of intensification was much less than ...
{"title":"Integrating Food Production into Nature's Biogeochemical Cycles","authors":"J. B. Robinson","doi":"10.4315/0022-2747-39.4.297","DOIUrl":"https://doi.org/10.4315/0022-2747-39.4.297","url":null,"abstract":"Elements such as nitrogen, carbon, phosphorus, and sulfur occur in the biosphere in a variety of chemical forms, each subject to biological or spontaneous conversion to other forms. In natural ecosystems such as grasslands and forests, these “cycles” operate very efficiently. The cycling of nitrogen in grassland is used to illustrate the conservative nature of natural systems. Food production, practiced on an extensive basis with minimum inputs and careful management may have minimum disruptive effects on local geochemical cycles, particularly if food is processed and consumed locally. Intensive agriculture, with its large energy inputs, and high yields, accompanied by extreme urbanization and remote food processing, induces major changes in local cycling. The localized effects of food production and processing have become a problem in industrialized countries which too often depend on food production, processing, and waste-treatment systems developed when the degree of intensification was much less than ...","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"406 1","pages":"297-300"},"PeriodicalIF":0.0,"publicationDate":"1976-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84866703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1976-03-01DOI: 10.4315/0022-2747-39.3.200
M. Solberg, D. K. Miskimin, R. Kramer, W. E. Riha, W. C. Franke, R. Buchanan, V. O'leary, K. A. Berkowitz
The sanitation surveillance system was developed with standards and follow-up actions as a part of an assurance program for microbiological safety in a university feeding system. The surveillance is based upon an adhesive contact and transfer tape system for surface monitoring and a micropore filter system for monitoring efficiency of the associated laundry operation. Results compiled from 3 years of operation generally show continued reductions in numbers of items testing below fully satisfactory. Specific systems of microbiological data analysis for detection of some mechanical or procedural breakdowns were developed. The overall cost for the entire laboratory part of the food safety assurance program was less than 0.5 cent per meal served.
{"title":"Assurance of Microbiological Safety in a University Feeding System","authors":"M. Solberg, D. K. Miskimin, R. Kramer, W. E. Riha, W. C. Franke, R. Buchanan, V. O'leary, K. A. Berkowitz","doi":"10.4315/0022-2747-39.3.200","DOIUrl":"https://doi.org/10.4315/0022-2747-39.3.200","url":null,"abstract":"The sanitation surveillance system was developed with standards and follow-up actions as a part of an assurance program for microbiological safety in a university feeding system. The surveillance is based upon an adhesive contact and transfer tape system for surface monitoring and a micropore filter system for monitoring efficiency of the associated laundry operation. Results compiled from 3 years of operation generally show continued reductions in numbers of items testing below fully satisfactory. Specific systems of microbiological data analysis for detection of some mechanical or procedural breakdowns were developed. The overall cost for the entire laboratory part of the food safety assurance program was less than 0.5 cent per meal served.","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"5 1","pages":"200-205"},"PeriodicalIF":0.0,"publicationDate":"1976-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79538142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1976-01-01DOI: 10.4315/0022-2747-39.1.4
Y. Yanai, B. Rosen, A. Pinsky, D. Sklan
Bacteriological and chemical parameters of ripe Israeli pickled cheese were highly correlated in cheese and pickle (brine). Lactobacilli were found in large numbers in commercial cheese. Sodium chloride concentration appeared to control the total viable population, the lactobacilli, and the amount of lactic acid produced. Coliform bacteria and enterococci were unaffected by the sodium chloride concentration found, but were affected by lactic acid. Numerical relationships between the above findings are given.
{"title":"Microbiology of Israeli Pickled Cheese","authors":"Y. Yanai, B. Rosen, A. Pinsky, D. Sklan","doi":"10.4315/0022-2747-39.1.4","DOIUrl":"https://doi.org/10.4315/0022-2747-39.1.4","url":null,"abstract":"Bacteriological and chemical parameters of ripe Israeli pickled cheese were highly correlated in cheese and pickle (brine). Lactobacilli were found in large numbers in commercial cheese. Sodium chloride concentration appeared to control the total viable population, the lactobacilli, and the amount of lactic acid produced. Coliform bacteria and enterococci were unaffected by the sodium chloride concentration found, but were affected by lactic acid. Numerical relationships between the above findings are given.","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"26 1","pages":"4-6"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81593358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1975-12-01DOI: 10.4315/0022-2747-38.12.774
B. Myers
Anisakine nematodes responsible for human anisakiasis have been recognized in fish hosts for over a decade. They are larval stages, relatively simple in form, and lack many morphological features used for identification of the adults (e.g., cephalic structures, spicules, etc.). However, these immature helminths can be sorted into larval types on the basis of the anterior digestive tract formation and the position of the excretory pore. Problems in identfying larvae, even as to type, are often encountered in tissue sections that may not show those anterior regions containing features of the digestive system which are diagnostic for type sorting. Hence, it is necessary to reconsider the diagnostic value of lateral chords, muscle cells, etc., that are visible in all cross-sections. Fish which are eaten by the human consumer also contain larval stages of other roundworms (nematodes) than those responsible for human anisakiasis, as well as numerous species of adult nematodes.
{"title":"The Nematodes that Cause Anisakiasis","authors":"B. Myers","doi":"10.4315/0022-2747-38.12.774","DOIUrl":"https://doi.org/10.4315/0022-2747-38.12.774","url":null,"abstract":"Anisakine nematodes responsible for human anisakiasis have been recognized in fish hosts for over a decade. They are larval stages, relatively simple in form, and lack many morphological features used for identification of the adults (e.g., cephalic structures, spicules, etc.). However, these immature helminths can be sorted into larval types on the basis of the anterior digestive tract formation and the position of the excretory pore. Problems in identfying larvae, even as to type, are often encountered in tissue sections that may not show those anterior regions containing features of the digestive system which are diagnostic for type sorting. Hence, it is necessary to reconsider the diagnostic value of lateral chords, muscle cells, etc., that are visible in all cross-sections. Fish which are eaten by the human consumer also contain larval stages of other roundworms (nematodes) than those responsible for human anisakiasis, as well as numerous species of adult nematodes.","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"30 1","pages":"498-498"},"PeriodicalIF":0.0,"publicationDate":"1975-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80858499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1975-11-01DOI: 10.4315/0022-2747-38.11.678
M. Doyle, E. H. Marth
{"title":"Thermal Inactivation of Conidia From Aspergillus flavus and Aspergillus parasiticus: I. Effects of moist heat, age of conidia, and sporulation medium","authors":"M. Doyle, E. H. Marth","doi":"10.4315/0022-2747-38.11.678","DOIUrl":"https://doi.org/10.4315/0022-2747-38.11.678","url":null,"abstract":"","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"7 1","pages":"678-682"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84274377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1975-11-01DOI: 10.4315/0022-2747-38.11.706
D. Fisher, R. Jacobson, I. Pflug
The quantity of water available to microorganisms influences both their growth and death kinetics. The water in microbial cells cannot be measured directly. The equilibrium atmospheric water conditions are usually measured and reported. The attributes of the several measuring units that can be used to indicate the water content in a gaseous atmosphere are described. Equations for their calculation and for converting from the several measurement units described to relative humidity at test temperature are presented.
{"title":"Indices of Water Content in Gaseous Systems, Their Measurement, and Relationship to Each Other","authors":"D. Fisher, R. Jacobson, I. Pflug","doi":"10.4315/0022-2747-38.11.706","DOIUrl":"https://doi.org/10.4315/0022-2747-38.11.706","url":null,"abstract":"The quantity of water available to microorganisms influences both their growth and death kinetics. The water in microbial cells cannot be measured directly. The equilibrium atmospheric water conditions are usually measured and reported. The attributes of the several measuring units that can be used to indicate the water content in a gaseous atmosphere are described. Equations for their calculation and for converting from the several measurement units described to relative humidity at test temperature are presented.","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"1 1","pages":"706-714"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72879965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1975-10-01DOI: 10.4315/0022-2747-38.10.594
Chanho H. Park, L. Mckay
Twelve commercial dairy starter cultures were examined for presence of lysogens by treating isolated strains with ultraviolet irradiation or mitomycin C. Induction of lysis in isolates from nine of the 12 commercial cultures suggested the presence of lysogenic strains. No indicator organisms were detected, but presence of phage was confirmed by electron microscopy in two of the Streptococcus cremoris isolates from the commercial cultures. The results confirm that some commercial dairy cultures produced in the United States contain phage-harboring strains.
{"title":"Induction of Prophage in Lactic Streptococci Isolated from Commercial Dairy Starter Cultures","authors":"Chanho H. Park, L. Mckay","doi":"10.4315/0022-2747-38.10.594","DOIUrl":"https://doi.org/10.4315/0022-2747-38.10.594","url":null,"abstract":"Twelve commercial dairy starter cultures were examined for presence of lysogens by treating isolated strains with ultraviolet irradiation or mitomycin C. Induction of lysis in isolates from nine of the 12 commercial cultures suggested the presence of lysogenic strains. No indicator organisms were detected, but presence of phage was confirmed by electron microscopy in two of the Streptococcus cremoris isolates from the commercial cultures. The results confirm that some commercial dairy cultures produced in the United States contain phage-harboring strains.","PeriodicalId":16561,"journal":{"name":"Journal of milk and food technology","volume":"120 1","pages":"594-597"},"PeriodicalIF":0.0,"publicationDate":"1975-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75887142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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