The pH of evaporated milk is a crucial factor that determines its quality, stability, and overall suitability for various culinary and industrial applications. Ranging from 6.10 to 6.30, the pH of evaporated milk is slightly more acidic than regular whole or skim milk, which typically has a pH of around 6.5 to 6.7. Understanding the factors that influence the pH of evaporated milk is essential for maintaining its optimal quality and performance.
Factors Affecting the pH of Evaporated Milk
Storage Temperature
The pH of evaporated milk is influenced by the storage temperature. Fresh evaporated milk typically has a pH of around 6.1, but this can drop to 5.9 or lower if stored at high temperatures. Proper storage conditions are crucial for preserving the pH and overall quality of evaporated milk.
Processing Conditions
The pH of evaporated milk can also be affected by the heat treatment and processing methods used. For example, wet heat pre-treatment of skim milk powder can improve the heat stability of recombined filled evaporated milk emulsions, which can impact the pH.
Contaminants and Chemicals in Evaporated Milk
Proteins
Milk proteins, such as casein and whey protein, can undergo denaturation and aggregation during heat treatment, affecting the pH and stability of evaporated milk.
Lactose
Lactose can react with proteins during heat treatment, leading to the formation of Maillard reaction products that can influence the pH and functional properties of evaporated milk.
Minerals
The presence of minerals like calcium and phosphorus can also impact the pH and stability of evaporated milk.
Balancing the pH of Evaporated Milk
Heat Treatment
Optimizing the heat treatment conditions can help maintain the pH and stability of evaporated milk.
Storage Conditions
Storing evaporated milk at lower temperatures can help preserve its pH and quality.
Additives
The use of additives like hydrolysed sunflower lecithin can improve the heat stability and pH of evaporated milk.
Helpful pH Range for Consumption
Consuming evaporated milk with a pH between 6.10 and 6.30 is generally considered safe and of good quality. However, if the pH drops below 6.0, the milk may become unacceptable due to phase separation and other quality issues.
History of pH in Evaporated Milk
The pH of evaporated milk has been extensively studied in the context of its heat stability and quality. Research has shown that various factors, including heat treatment, storage conditions, and processing methods, can influence the pH of evaporated milk.
Solutions and Alternatives
- Optimized Heat Treatment: Using optimized heat treatment conditions can help maintain the pH and stability of evaporated milk.
- Alternative Processing Methods: Exploring alternative processing methods, such as dry heat incubation, can help improve the pH and functional properties of evaporated milk.
- Additives and Stabilizers: Using additives and stabilizers like hydrolysed sunflower lecithin can help improve the pH and heat stability of evaporated milk.
References
- Wu, J., et al. (2022). Improved heat stability of recombined filled evaporated milk emulsions by wet heat pre-treatment of skim milk powder. Journal of Food Engineering, 309, 110-120. doi: 10.1016/j.jfoodeng.2022.01.015
- ThoughtCo. (2022). What Is the Acidity or pH of Milk? Retrieved from https://www.thoughtco.com/what-is-the-ph-of-milk-603652
- Webb, B. H., et al. (1951). Effects of Storage Temperature on Properties of Evaporated Milk. Journal of Dairy Science, 34(9), 1114-1125. doi: 10.3168/jds.S0022-0302(51)91833-4
- PickYourOwn.org. (n.d.). pH of Eggs and Dairy. Retrieved from https://www.pickyourown.org/pH-of-dairy-eggs.php.