Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1971 Studies on a Newly Developed White Cheese. Edward Halim Youssef Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Youssef, Edward Halim, "Studies on a Newly Developed White Cheese." (1971). LSU Historical Dissertations and Theses. 2101. https://digitalcommons.lsu.edu/gradschool_disstheses/2101 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. 72-3537 YOUSSEF, Edward Halim, 1939- STUDIES ON A NEWLY DEVELOPED WHITE CHEESE. The Louisiana State University and Agricultural and Mechanical College, Ph.D., 1971 Agriculture, general I University Microfilms, A XEROX Company, Ann Arbor, Michigan @ 1971 EDWARD HALIM YOUSSEF ALL RIGHTS RESERVED THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED STUDIES ON A NEWLY DEVELOPED WHITE CHEESE A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Hie Department of Dairy Science by Edward Halim Youssef B.S., Ain Shames University, Cairo, Egypt, 1959 M.S., Ain Shames University, Cairo, Egypt, 1966 August, 1971 t / PLEASE NOTE: Some Pages have in d is tin c t prin t. Filmed as received. UNIVERSITY MICROFILMS ACKNOWLEDGMENTS The author is grateful to his major Professor, Dr. J. H. Gholson, for guidance during the course of his graduate studies at Louisiana State University, and for his assistance in the preparation of this dissertation. The help of Dr. J. B. Frye, Jr., Head, Louisiana State University, Dairy Science Department, is acknowledged, and gratitude is expressed to the department for financial assistance. The author wishes to thank Dr. R. A. Teekell of the Poultry Science Department for his assistance in the conduct of amino acid analysis phase of the research. Thanks are also due to Dr. W. F. McKnight of the Home Economics Department and Dr. L. L. Russof of the Dairy Department for supplying facilities for the gas chromatography work. The author is grateful to the members of his committee, Dr. J. H. Gholson, Dr. J. B. Frye, Jr., Dr. R. M. Grodner and Dr. F. H. Hoskins, of the Food Science Department and Dr. A. D. Larson of the Microbiology Department for their guidance and assistance during the course of the research and for the editing of the dissertation. Thanks are also due to the evaluation panel, Dr. J. H. Gholson, Dr. R. H. Gough, Mr. J. D. Ortego, Mr. D. W. Crain and Mr. R. Toma. Special recognition is also extended to the author's wife, Madlen, for her encouragement and assistance during the course of this study. ii TABLE OF CONTENTS Page ACKNOWLEDGMENTS.............................................. ii LIST OF TABLES................................................ v LIST OF FIGURES.............................................. vi ABSTRACT...................................................... vii INTRODUCTION. .......................................... 1 REVIEW OF LITERATURE.......................................... 4 Technological Improvements of White Pickled Cheese in the United States ........................................ 4 Technological Improvements of Pickled Cheese Outside the United States ........................................ 6 Low Fat Pickled White Cheese................................ 7 Chemical Composition of White Cheese......................... 8 Fat, Free Fatty Acids and Its Relation to Flavor........... 10 Total, Soluble Protein and Free Amino Acids .............. 13 Bacteriological Studies on White Pickled Cheeses............. 15 Potentialities in New and Improved Type Cheeses............. 15 EXPERIMENTAL METHODS.......................................... 18 Statement of the Problem.................................... 18 Experimental Procedures.................................... 18 Experiment 1 .............................................. 18 Trial ( 1 ) .............................................. 19 Trial ( 2 ) .............................................. 19 Experiment I I ........................ 20 Experiment III............................................ 20 Experiment I V ............................................ 20 Experiment V .............................................. 24 Experiment V I ............................................ 24 Experiment VII............................................ 24 Product Judging ............................................ 26 Collection and Preparation of Samples....................... 26 Chemical Analysis of C h e e s e ................................ 26 Moisture Content.......................................... 26 Fat Percentage............................................ 27 Salt Content.............................................. 27 Titratable Acidity........................................ 27 pH........................................................ 28 ill Page Total Nitrogen Content.................................... 28 Soluble Nitrogen Content.................................. 28 Free Fatty Acids.......................................... 28 Short Chain Fatty Acids (C2-C5) ........................ 28 Long Chain Fatty Acids (Cg-C^g) ........................ 29 Free Amino Acids.......................................... 30 Bacteriological Analysis of Cheese.......................... 30 Standard Plate Count...................................... 31 C o l i f o r m s ................................................ 31 Yeast and Mold............................................ 31 Proteolytic Activity...................................... 31 Psychrophilic Count ...................................... 31 RESULTS AND DISCUSSION........................................ 32 Organolyptic Qualities and Appearance ...................... 32 Experiment 1 .............................................. 32 Experiment I I ............................................ 33 Experiment III............................................ 35 Experiment I V ............................................ 36 Experiment V .............. 36 Experiment V I ............................................ 37 Experiment VII ............................................ 38 Chemical Changes During Ripening............................ 39 Moisture.................................................. 39 F a t ...................................................... 42 Titratable Acidity........................................ 43 Hydrogen-ion Concentration................................ 44 Salt Content.............................................. 44 Total and Soluble Protein ................................ 45 Free Fatty Acids.......................................... 47 Free Amino Acids.......................................... 51 Bacteriological Changes During Ripening ..................... 54 SUMMARY AND CONCLUSIONS..................... 57 SELECTED BIBLIOGRAPHY......................... 59 APPENDIX...................................................... 64 VITA.......................................................... 67 iv LIST OF TABLES TABLE Page 1. Average Composition of White Cheese During Ripening P e r i o d ................................................ 40 2. Average Composition of White Cheese During Ripening Period (Dry B a s i s ) .................................... 41 3. Free, Water Soluble Fatty Acid Content During Ripening.............................................. 49 4. Free, Non-water Soluble Fatty Acid Content During Ripening.............................................. 50 5. Free Amino Acid Content During Ripening.................. 52 6 . Average Bacterial Content of White Cheese During Ripening.............................................. 55 v LIST OF FIGURES FIGURE Page 1. Diagram of Experiment I .................................. 19 2. Diagram of Experiment II.................................. 21 3. Diagram of Experiment II I ................................ 22 4. Diagram of Experiment IV.................................. 23 5. Diagram of Experiment V .................................. 24 6 . Diagram of Experiment VI............. 25 7. Diagram of Experiment VI I ................................ 25 vi ABSTRACT The firsC phase of this investigation was to study the possibility of developing a new or modified cheese product. Hie manufacturing procedure is based on the traditional methods of making "Feta Cheese", a popular white cheese in the Near East countries. Pilot scale experiments revealed that traditional make procedures could be modified to produce an acceptable product for the American consumer. Results of consumer evaluation showed that 78% would buy this new cheese at a reasonable price. It is characterized by its smooth, creamy, sliceable body, slight acid and salty taste, and mild, savory, piquant type flavor. The new cheese can be consumed as a mild fresh product 5-7 days after manufacture, or as a more flavorful product after 4-5 weeks of ripening at 7-10°C. The second phase was a study of the chemical and bacteriological composition of the fresh product and the changes during ripening of this cheese, with special emphasis on flavor. The average composition after three weeks of ripening