Fundamentals of Water Holding Capacity (WHC) of Meat

Table of Contents

1. Introduction
   1. Objectives
   2. Learning goals
   3. Teacher page
2. List of Abbreviations used in this Learning Resource
3. Section I: Introduction and Significance of WHC
   1. What is WHC?
   2. Overview of Proteins, Fat, pH and Water and WHC
   3. Compartments for Holding Water in Meat
   4. Activity - Section I
4. Section II: Major Factors Affecting WHC
   1. Role of Animal Genetics and WHC
   2. Role of Pre-harvest Handling of Pigs on WHC
   3. Conversion of Muscle-to-Meat Issues and WHC
   4. Muscle Extensibility and Rigor Mortis
   5. Activity - Section II
5. Section III: Mechanism for Holding of Water in Pork
   1. Concepts for holding of Water in Meat
   2. How is Water Held in Meat?
   3. Graphic Representation of WHC and Important Concepts
   4. Examples of Extrinsic Factors Affecting WHC of Processed Meats
   5. Activity - Section III
6. Section IV: Fundamental Science of Water Holding Capacity
   1. Expanding the Knowledge of WHC
   2. The Assignment
   3. Activity - Section IV
7. Section V: Methods for Determining WHC
   1. Complexity of Measuring WHC
   2. What Moisture Categories of Water need to be Measured?
   3. Video: Great Visualization of four WHC Methods
   4. Methods for Measuring WHC of Meat
   5. Activity - Section V
8. Section VI: Recent Advances in Measuring & Monitoring WHC
   1. Need for Fast, Real-time, Non-destructive WHC Methods
   2. Potential Fast and Non-destructive Methods
   3. Activity - Section VI
9. Selected References related to WHC
10. References: Q-Pork Chain & Other Instrumental Methodology for WHC
11. Completion
    1. Comments
    2. Self assessment
    3. Evaluation
12. Acknowledgement

Role of Pre-harvest Handling of Pigs on WHC

Meat animals, like humans, respond in different ways to stress. "Stress-susceptible" animals cannot easily handle the loading, hauling, crowding, weather conditions, and the mixing with other strange animals. These animals respond by increasing their heart rate, respiratory rate, and muscle metabolic rate, all of which have negative effects on rigor mortis, protein denaturation, WHC, and meat functionality. Livestock producers may increase the population of problematic animals by using stress susceptible animals in their breeding programs. Producers often ignore or do not know how to handle the ante-mortem effects that contribute to lower pork quality. In addition, meat plant operations often do not know the ante-mortem history of each group of animals that they purchase. Thus, a more "systems" approach to marketing and slaughter of pigs can help maximize desirable meat processing procedures that minimize negative effects on the meat's WHC.

All animals should be properly handled ante-mortem, so abnormal quality is not induced even in pigs without the stress gene. In fact, about 8 to 15% of pigs not carrying the stress gene have some undesirable variations in quality traits at many plant operations. The most common causes for this are less than optimal handling practices, inadequate chilling, or a combination of both. Given that certain genes or other gene-related traits may cause variation in meat quality due to increased susceptibility to the physical and social challenges of hauling and lairage before slaughter, the entire system of ante-mortem conditions should be carefully monitored to minimize live animal factors from significantly influencing the WHC of meat.

Gentle, calm handling of livestock the last few minutes before stunning is critically important for preventing an undesirable increase in the rate of pH decline (which decreases WHC) early post-mortem. Electrical stunning is not necessarily worse than CO₂ stunning for accelerating pH declines; but the group handling capability with CO₂ stunning has some advantages. See Learning Resources 'Driving Pigs to Stunning' and 'Animal Welfare-friendly Housing Systems' for more information about handling and welfare issues for pigs.