T This dissert itlon has been microfilmed e> actlyab received 70-6793 HILDEBOLT, William Morton, 1943- THE INFLUENCE OF PRESERVATION METHODS OF THE COLOR AND OTHER QUALITY ATTRIBUTES OF GREEN BEANS (FHASEOLUS VULGARIS L.) The Ohio State University, Ph.D., 1969 Food Technology University Microfilms, Inc., Ann Arbor, Michigan TIE INFLUENCE OF PRESERVATION METHODS OF THE COLOR AND OTHER j . QUALITY ATTRIBUTES OF GREEN BEANS (PHASEOLUS VULGARIS L.) DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By William Morton Hildebolt, M.S. ****** The Ohio State University 1969 Approved by fa ftJUs-Q.-hrdtf Adviser Department of Horticulture and Forestry ACKNOWLEDGMENT The author wishes to express his appreciation and gratitude to the following: my wife, Sandra, and my family, for their constant encouragement, understanding, and assistance throughout my graduate studies. Ify adviser, Dr. Wilbur A. Gould, for his guidance, assistance, • and learned counsel. Dr. Jean R. Geisman, for his suggestions and guidance in the final preparation of this manuscript. Dr. C. Richard Weaver and the Statistics Laboratory of the Ohio Agricultural Research and Development Center, Wooster, Ohio, for their help in analyzing the results of this project. The staff and many students of the Food Processing and Tech­ nology Division, Department of Horticulture and Forestry, for their help in the processing of the many samples required for this study, and special thanks to Dr. David E. Crean for his technical assistance. ii VITA December 7, 1943 . Born - Richmond, Indiana 1966 .............. B.S. in Food Technology, The Ohio State University, Columbus,. Ohio 1966-1967...... Teaching Assistant, Horticulture Department, The Ohio State University, Columbus, Ohio 1967 .............. M.Sc., The Ohio State University, Columbus, Ohio 1967-196 8 .......... Teaching Associate, Horticulture Department, The Ohio State University, Columbus, Ohio PUBLICATIONS "Evaluation of Snap Bean Varieties for Processing," Research Progress Reports, Ohio Agricultural Research and Development Center, Mimeo­ graph Report #337:1-10, 1967 (Co-author Dr. W. A. Gould). "Epidermal Sloughing of Snap Beans as Influenced by Processing Variables," Research Progress Reports, Ohio Agricultural Research and Development Center, Mimeograph Report #337:28-32, 1967 (Co-author Dr. W. A. Gould). "Effect of Nitrogen Levels on Tomato Fruit and Internal Can Corrosion Using the Diphenylamine Spot Test," Research Progress Reports, Ohio Agricultural Research and Development Center, Mimeograph Report #339:32-35, 1968 (Co-author Dr. W..A. Gould). "Evaluation of Snap Bean Cultivars for Processing," Research Progress Reports, Ohio Agricultural Research and Development Center, Mimeo­ graph Report #350:11-16, 1969 (Co-author Dr. W, A. Gould). iii FIELDS OF STUDY Major Field: Horticulture Studies in Processing Fruits and Vegetables. Professor Wilbur A. Gould and James F. Gallander. Studies in Specialty Products. Professor Jean R. Geisman. I • Studies in Microbiology. Professor Harry H. Weiser. Studies in Physical Chemistry. Professor Quentin Van Winkle. iv TABLE OF CONTENTS Page ACKNOWLEDGMENTS.......... ^ ........................... ii VITA .................................... ................... iii LIST OF TABLES ..................... ................... vi LIST OF F I G U R E S ............................................. X INTRODUCTION ............ ' ................................. 1 REVIEW OF LITERATURE ......................................... 3 G e n e r a l .......................... .................. 3 , Theoretical Concepts of Color and Color Measurement . 3 Factors Influencing Color and■Chlorophyll Retention . 15 Factors Influencing Other Quality Attributes ........... 26 MATERIALS AND METHODS ................................. 31 Cultural Information.............. .................. 31 Processing . ................. 32 Product Evaluation ................................... 36 PRESENTATION OF RESULTS . ................................. 46 G e n e r a l ............. .......... ..................... 46 Colorimetry ............. ........................... 47 Product Evaluation ............ ............ 54 DISCUSSION OF RESULTS ....................................... 95 G e n e r a l ............................................. 95 Colorimetry ......................................... 95 Product Evaluation ................................... 101 CONCLUSION........................... .............. ......... 114 APPENDIX........... H 8 BIBLIOGRAPHY............................. ................... 155 V LIST OF TABLES Table Page 1 Snap Bean Cultivars .......... ................. 31 2 Subjective Sloughing Evaluation .;..... 44 3 Correlation Coefficients of Colorimetry Function With the Percent Chlorophyll Retention (Total, a, and b) by Processing M e t h o d ................................ 49 4 Correlation Coefficients of Colorimetry Functions by Processing Method ............... 51 5 Correlation Coefficients of Colorimetry Function With the U.S.D.A, Color Scores for Canned, Frozen, and Freeze- Dried Snap B e a n s ..................... 53 6 Analysis Averages of Raw and Blanched Samples ....... 54 7 Relationship of Percent Chlorophyll Retention (Total, a and b) and Reflectance Colorimeter (Agtron M-400 and Hunter D-25) Results for the Raw Analysis as Expressed by Linear and Multiple Regression Equations . 56 8 Agtron R Results From Steam (210°F for 1 Minute) and Water (185°F for 2 Minutes) Blanches for Whole Green B e a n s ........................ 57 9 Averages of the Percent Chlorophyll Retentions (Total, a, and b) and Agtron R Results for Various Blanching Treatments for Cut Green B e a n s ......................... 58 10 Relationship of Percent Chlorophyll Retention (Total, a and b) and the Reflectance Colorimetric (Agtron M-400 and Hunter D-25 Results for Blanched Samples as Expressed by Linear and Multiple Regression Equations ......... 60 11 Analysis Averages of the Canned (Buffered Brine) and Canned (Water Brine) Samples ............... 61 12 Averages of the Percent Chlorophyll Retention, U.S.D.A, Color Scores, and Agtron R Results from the Canned (Water Brine) Samples Which Were Steam Blanched (210°F for 1 Minute) According to Maturity Classification and * Storage P e r i o d ......... '................................ 63 vi LIST OF TABLES (Continued). Table Page 13 Averages of the Percent Chlorophyll Retentions, U.S.D.A, Color Scores, and Agtron R Results from the Canned (Water Brine) Samples Which Were Water- Blanched (185°F for 2 Minutes) According to Maturity Classification and Storage Period ........ ........................... 64 14 Averages of the Percent Chlorophyll Retention, U.S.D.A. Color Scores, and Agtron R Results from the Canned (Buffered Brine) Samples for the Cut Maturity Classifi­ cation According to the Blanching Method and Storage Period .... ....................................... 65 15 Averages of the Percent Chlorophyll Retention, U.S.D.A. Color Scores, and Agtron R Results from the Canned Samples (Water Brine) Which Wfere Blanched in Buffer Solutions (pH 6.7 to 8.0) According to the Cut Maturity Classification and Storage Period ...................... 66 .16 Relationship of the U.S.D.A. Color Scores and the Percent Chlorophyll Retentions (Total, a, and b) and the Reflec­ tance Colorimetric (Agtron M-400 and Hunter D-25) Results for the Canned (Water Brine) Samples as Expressed by Linear and Multiple Regression Equations .............. 67 17 Analysis Averages of the Frozen and Freeze-Dried S a m p l e s ............................ .'............ 69 v 18 Averages of the Percent Chlorophyll Retention, U.S.D.A. Color Scores, and Agtron R Results from the Frozen Samples Which Were Steam Blanched (210°F for 1 Minute) According to Maturity Classification and Storage Period .......................... .......... 70 19 Averages of the Percent Chlorophyll Retention, U.S.D.A. Color Scores, and Agtron R Results from the Frozen Samples Which Were Water Blanched (185°F for 2 Minutes) According to Maturity Classifications and Storage P e r i o d ............................. ................ 71 20 Averages of the Percent Chlorophyll Retentions, U.S.D.A, Color Scores, and Agtron R Results from the Frozen Samples Which Were Blanched in Buffer Solutions (ph 6.7 to 8.0) According to the Cut Maturity Classification and Storage Period . ............................. 72 vii LIST OF TABLES (Continued) Table , • > Page 21 Relationship of the U.S.D.A. Color Scores and the Percent Chlorophyll Retentions (Total, a, and b) and the Reflectance Colorimetric (Agtron M-400 and Hunter D-25) Results for the Frozen Samples as Expressed by Linear and Multiple Regression Equations ............. 80 22 Averages of the Percent Chlorophyll Retentions, Visual Color Scores, and Agtron R Results from the Freeze-Dried Samples Which Were Steam Blanched (210°F for 1 Minute) According to Maturity Classification and Storage Period............................................... 81 23 Averages of the Percent Chlorophyll Retentions, Visual Color Scores, and Agtron R Results from the Freeze-Dried Samples Which Were Water Blanched (185°F for 2 Minutes) According to Maturity Classifications and Storage P e r i o d ..................... 82 24 Averages of the Percent Chlorophyll Retention, U.S.D.A. Color Scores, and Agtron R Results from the Freeze-Dried Samples in Which Were Blanched in Buffer Solutions (6.7 to 8.0) According