Why does canned pineapple not contain bromelain? The science of heat inactivation

December 8, 2025 •

4 min read

Pineapple is the only major dietary source of bromelain, but canned pineapple does not contain bromelain. The scientific reason lies in the fruit's exposure to high temperatures during the canning process, which denatures the delicate enzyme and renders it inactive.

Quick Summary

Canned pineapple lacks bromelain because the enzyme is destroyed by the high heat sterilization required for food preservation. This process deactivates the heat-sensitive protein.

Key Points

Enzyme Inactivation: The high-heat process used to sterilize canned pineapple completely denatures and inactivates the bromelain enzyme.
Heat Sensitivity: Bromelain is highly sensitive to heat, and temperatures above 60°C (140°F) are known to cause it to lose its enzymatic activity.
Culinary Implications: The lack of active bromelain allows canned pineapple to be used in gelatin-based desserts, unlike fresh pineapple which prevents gelatin from setting.
Meat Tenderizing: Canned pineapple will not tenderize meat, whereas fresh pineapple's active bromelain can break down protein fibers.
Nutritional Trade-offs: While bromelain is lost and some water-soluble vitamins like Vitamin C are reduced, canned pineapple retains many other nutrients, including fiber and minerals.
Processing Purpose: The purpose of canning is to create a safe, shelf-stable product, and the heat required for this process is what destroys the enzyme.

The Heat-Sensitive Nature of Bromelain

Bromelain is a collective term for a group of proteolytic enzymes, or proteases, found in the pineapple plant (Ananas comosus). In fresh pineapple, these enzymes are responsible for the tingling sensation some people feel on their tongue and are powerful enough to break down the collagen in gelatin, preventing it from setting. However, the defining characteristic of bromelain, and the key to understanding its absence in canned pineapple, is its sensitivity to heat. Like many enzymes, bromelain has a specific three-dimensional structure that is essential for its function. When exposed to heat, the high energy causes this structure to unravel, a process known as denaturation. Once the enzyme is denatured, its shape changes, and it can no longer perform its enzymatic function of breaking down proteins. The temperature at which this occurs is well below the boiling point.

What Happens During Canning?

The commercial canning process involves packing prepared fruit into cans with syrup or juice and then subjecting the sealed containers to high temperatures. This heat treatment is critical for two main reasons: to sterilize the product and ensure a long, stable shelf life by destroying any microorganisms, and to pasteurize the fruit. The temperature and duration vary, but studies have shown that temperatures as low as 60-70°C (140-158°F) can begin to inactivate bromelain. The typical canning process uses even higher temperatures, ensuring that the bromelain is completely and consistently inactivated. This is why canned pineapple does not cause the same tingling sensation as fresh pineapple and can be used in gelatin-based desserts without issue. It is the very process designed to make the fruit safe and shelf-stable that eliminates its enzymatic activity.

What is Bromelain and Its Functions?

Bromelain's properties have been recognized for centuries, and it is known for several key functions in both culinary and medicinal applications.

Protein Digestion and Jello

As a protease, bromelain digests proteins. This is most famously demonstrated by its effect on gelatin, which is made from collagen, an animal protein. The active bromelain in fresh pineapple breaks down the collagen molecules, preventing them from forming the necessary cross-links to set into a semi-solid gel. In contrast, since the bromelain in canned pineapple is inactive, it has no effect on gelatin, making it the preferred choice for desserts like pineapple jello.

Meat Tenderizing

The same protein-digesting ability that affects gelatin is what makes fresh pineapple a potent meat tenderizer. The enzyme breaks down the collagen and muscle fibers in meat, softening its texture. This effect, however, is entirely absent with canned pineapple because the enzyme is no longer active. For this reason, a meat marinade with fresh pineapple will tenderize meat, while one made with canned pineapple will not.

Comparison: Fresh vs. Canned Pineapple


Feature	Fresh Pineapple	Canned Pineapple
Bromelain Content	High concentration, especially in the core and stem.	Virtually non-existent; inactivated by heat.
Heat Exposure	None (unless cooked).	Exposed to high temperatures during canning.
Effects on Gelatin	Prevents it from setting properly.	Has no effect on gelatin; can be used in gelatin desserts.
Meat Tenderizing	Acts as a natural meat tenderizer.	Does not tenderize meat.
Flavor Profile	Tangy, vibrant, and sometimes causes a tingling sensation.	Generally sweeter, often packed in syrup, with a softer texture.
Vitamin C Content	Higher levels of heat-sensitive vitamins, including Vitamin C.	Lower levels of Vitamin C due to heat processing.

Why Canned Pineapple is Still a Good Option

Despite the loss of bromelain, canned pineapple remains a valuable and nutritious food.

Convenience and Shelf-Life

Canned pineapple offers unparalleled convenience and a significantly longer shelf life than fresh fruit. It is readily available year-round, pre-cut and prepared, making it easy to incorporate into recipes or enjoy as a quick snack. This accessibility is especially beneficial when fresh pineapple is out of season or unavailable.

Nutrient Retention

While water-soluble vitamins like Vitamin C are reduced, many other nutrients are retained through the canning process. Canned pineapple is still a good source of:

Dietary fiber, which is largely unaffected by heat and essential for digestive health.
Manganese, a vital mineral involved in bone formation and metabolism.
Carbohydrates and minerals, which remain largely intact during canning.

Conclusion

The short answer to why canned pineapple does not contain bromelain is the high heat of the canning process. This heat denatures the enzyme, effectively deactivating its protein-digesting abilities. While this means canned pineapple can't tenderize meat or prevent gelatin from setting, it doesn't diminish its value as a convenient and nutritious food source. The key difference highlights the fascinating science of enzymes and how food processing techniques can alter a food's properties, allowing consumers to choose between fresh and canned versions based on their culinary and nutritional needs. For more information on food safety and nutrition, consult authoritative sources like the Academy of Nutrition and Dietetics.

Frequently Asked Questions

Bromelain is a group of proteolytic enzymes found in pineapple that are capable of breaking down proteins. It is special because it is a potent protein-digesting enzyme, and fresh pineapple is a primary dietary source.

Yes, while the bromelain is lost and some heat-sensitive vitamins are reduced, canned pineapple still contains beneficial nutrients like fiber, manganese, and many minerals.

The tingling or raw feeling in your mouth when eating fresh pineapple is caused by the active bromelain enzyme, which is temporarily breaking down the proteins on the delicate lining of your mouth.

Bromelain is highly heat-sensitive, and studies show it begins to lose activity above 40°C (104°F), with significant or complete inactivation occurring at temperatures of 60-80°C (140-176°F) and above.

No, you cannot use canned pineapple to tenderize meat. The bromelain enzyme, which is responsible for the tenderizing effect in fresh pineapple, is destroyed during the canning process.

Yes, gelatin will set perfectly fine if you use canned pineapple. The heat treatment in canning inactivates the bromelain, which would otherwise prevent the gelatin from solidifying.

Both have nutritional value. Fresh pineapple is the only source of active bromelain and has higher levels of Vitamin C. Canned pineapple, while lacking bromelain, is a convenient source of other nutrients like fiber and minerals.

A good indication is to see if its specific function is affected by cooking. For example, if adding a raw ingredient to a recipe yields a different result than adding a cooked version, it may be due to a heat-sensitive enzyme, as is the case with fresh pineapple and gelatin.