University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Dissertations, Theses, & Student Research in Food Science and Technology Food Science and Technology Department Fall 9-19-2011 Effect of Sodium Nitrite, Sodium Erythorbate and Organic Acid Salts on Germination and Outgrowth of Clostridium perfringens Spores in Ham during Abusive Cooling Mauricio A. Redondo University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/foodscidiss Part of the Food Chemistry Commons, Food Microbiology Commons, and the Food Processing Commons Redondo, Mauricio A., "Effect of Sodium Nitrite, Sodium Erythorbate and Organic Acid Salts on Germination and Outgrowth of Clostridium perfringens Spores in Ham during Abusive Cooling" (2011). Dissertations, Theses, & Student Research in Food Science and Technology. 18. https://digitalcommons.unl.edu/foodscidiss/18 This Article is brought to you for free and open access by the Food Science and Technology Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Dissertations, Theses, & Student Research in Food Science and Technology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. EFFECT OF SODIUM NITRITE, SODIUM ERYTHORBATE AND ORGANIC ACID SALTS ON GERMINATION AND OUTGROWTH OF CLOSTRIDIUM PERFRINGENS SPORES IN HAM DURING ABUSIVE COOLING By Mauricio Redondo-Solano A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science Major: Food Science and Technology Under the supervision of Professor Harshavardhan Thippareddi Lincoln, Nebraska September, 2011 EFFECT OF SODIUM NITRITE, SODIUM ERYTHORBATE AND ORGANIC ACID SALTS ON GERMINATION AND OUTGROWTH OF CLOSTRIDIUM PERFRINGENS SPORES IN HAM DURING ABUSIVE COOLING Mauricio Redondo-Solano, M. S. University of Nebraska, 2011 Advisor: Harshavardhan Thippareddi The effect of sodium nitrite (NaNO2), sodium erythorbate, sodium chloride (NaCl) and organic acid salts (potassium lactate and sodium diacetate) on C. perfringens spore germination and outgrowth in ham was evaluated. The research was divided in two parts. The first experiment consisted of potential C. perfringens spore germination and outgrowth in ham containing combinations of NaNO2 (0, 50, 100, 150 or 200 ppm) and sodium erythorbate (0 or 557 ppm) during cooling. This experiment included the evaluation of residual nitrite levels as affected by temperature (heat shock at 75°C for 20 min and subsequent cooling from 54.4°C to 4.4°C within 15 h), storage time (3 and 24 h at 5°C) and sodium erythorbate concentration. Inhibition of C. perfringens spore germination and outgrowth was observed after 3 h of ham preparation in all the treatments evaluated. Greater inhibition of C. perfringens was observed with higher concentrations of NaNO2. Addition of sodium erythorbate resulted in greater C. perfringens populations subsequent to 15 h of abusive cooling. Residual nitrite concentrations were similar under the experimental conditions used in this study. Residual oxygen in the ham could explain the inhibition observed during cooling of the ham within 3 h of preparation. During the second experiment, the effect of NaNO2 (0 or 100 ppm), NaCl (1 or 2%) and organic acid salts (Opti.Form PD4®; 0, 1.5 or 2.5%) on C. perfringens spore germination and outgrowth during abusive cooling was evaluated. Incorporation of Opti.Form PD4® (1.5%) inhibited C. perfringens spore germination and outgrowth regardless of the cooling rate (9, 15 or 21 h). Addition of NaNO2 enhanced the antimicrobial activity of organic acid salts. Shorter time period between ham preparation and heat treatment/cooling resulted in greater inhibition of C. perfringens spore germination and outgrowth. Antimicrobial agents should be incorporated into ham formulations in case reductions in NaCl and NaNO2 concentrations are considered in view of the recommendation to reduce sodium content in the diet. A C K N O W L E D G M E N TS In the first place I would like to thank God for the blessings I have received in my life. In second place I must thank my mother and sisters for their support through my entire journey during my academic life. To my mother I owe everything I am and everything I have accomplished. This work is especially dedicated to her. For Carol, my wife, I do not have enough words to express the importance of her presence in my life and how important she was for finishing this project. The real meaning of this DFFRPSOLVKPHQWKDV&DURO¶VQDPHDQGDOOP\0DVWHU¶VH[SHULHQFHPDGHVHQVHIURPWKH beginning because of her. A special mention to my advisor Dr. Harshavardhan Thippareddi, who gave me the opportunity to be part of the UNL family and has helped me to expand my professional criteria and scientific perspective. He knows that, after accepting me as a student, he changed my life in many ways. Finally, I would like to thank the University of Costa Rica and my friends in there for the continuous support and opportunities during the last 3 years. ! i T A B L E O F C O N T E N TS List of Figures ......................................................................................................................... vi List of Tables......................................................................................................................... viii Introduction ............................................................................................................................. ix I. CHAPTER 1 ........................................................................................................................... 1 Literature review ...................................................................................................................... 2 1. Clostridium perfringens .......................................................................................................... 2 1.1. General characteristics ....................................................................................................... 3 1.2. Toxin production by C. perfringens .................................................................................. 4 1.3. Occurrence of disease and pathogenesis ........................................................................... 5 1.4. Historic background and current health impact ................................................................. 8 1.5. Implicated foods and control ........................................................................................... 10 2. Sodium nitrite for curing and preservation of meat products ......................................... 13 2.1. General information ......................................................................................................... 13 2.2. Historic background of meat curing ................................................................................ 14 2.3. The chemical process of meat curing .............................................................................. 16 2.4. Antimicrobial aspects of nitrites in cured products ......................................................... 18 2.5. C. perfringens sensitivity to nitrites ................................................................................ 21 2.6. Nitrite regulation in meat products and health concerns ................................................. 23 2.7. Presence of sodium erythorbate in cured products .......................................................... 27 3. Determination of nitrite in cured meat products .............................................................. 28 3.1. Presence of nitrite in meat products ................................................................................ 28 ! ii 3.2. Monitoring of nitrite in cured products ........................................................................... 32 3.3. Technical considerations for analysis of nitrites in cured meats ..................................... 33 3.4. Analytical methods for nitrites in cured meats ................................................................ 35 3.5. High Performance Liquid Chromatography (HPLC) for nitrites in cured meats ............ 37 4. Reduction of sodium content in meat products ................................................................. 41 4.1. General background ......................................................................................................... 42 4.2. Metabolic activityof sodium ............................................................................................ 44 4.3. Excessive sodium intake and high blood pressure .......................................................... 45 4.4. Salt, an ingredient with powerful technical functions for meat products ........................ 50 4.5. Antimicrobial properties of salt ....................................................................................... 53 4.6. Microbiological studies in reduced salt products ............................................................ 56 5. Use of organic acids and their salts for food preservation ............................................... 57 5.1. General information ......................................................................................................... 57 5.2. Regulation and health concerns ....................................................................................... 59 5.3. Applications of organic acids and their salts in foods