The Hyped-Up Food Additive: Why Are Indians Obsessed with Papain?

Have you ever come across a curious news story about how Indians love growing papayas and, even when the fruit is still unripe, they make cuts all over it? In just seconds, a milky white liquid oozes from the papaya, and the locals quickly collect it in containers to sell. In some parts of India, people even make a living off of this papaya sap. So, why do people slice into the unripe papaya to gather this white liquid? What makes it so valuable?

It turns out that the process of cutting into an unripe papaya and collecting the milky sap is highly specialized. This variety of papaya is not the edible kind—its nutritional value is low, but its economic value is high. The fruit doesn’t need to fully ripen. Once it grows large enough, people cut into its surface, and the papaya releases that milky substance, known as papain.

Papain is a proteolytic enzyme, meaning it breaks down proteins, and it has protease activity. Papain isn’t just popular in Southeast Asia—it has a similarly elevated status in China, where it has even been referred to as a "legendary" food additive. To many seasoned chefs, papain is the secret weapon for marinating and tenderizing meat.

Some have placed it on a pedestal because, compared to chemical additives, papain is a natural biological product. It seems healthier, which is why many people blindly trust that using papain in food not only makes meat more tender but also enhances the overall texture. But is papain really that magical? Can it genuinely be considered a healthy food additive?

Research has shown that papain breaks down muscle proteins and collagen. You can think of it like a sharp knife—when it comes into contact with muscle tissue, it quickly severs the muscle fibers. With this mechanism at play, papain can indeed be used as a natural marinade, making meat products smoother and less tough in no time.

Moreover, beyond breaking down muscle fibers, papain also hydrolyzes elastin and collagen in meat products, releasing pigments from the food. After this kind of marination, the meat becomes plump, tender, and more appetizing. From a nutritional perspective, this makes the meat easier for the human body to digest and absorb. However, some critics argue that using papain as a food additive strips the marinated meat of its original flavor.

It’s often said that food is essential to life, and learning about chemical products is part of that. But we shouldn’t underestimate the progress and strategic importance of chemical agents. Beyond its use as a natural meat tenderizer, papain is also closely tied to a nation or region’s biochemical advancements.

Papain's applications are broad, extending beyond the food industry into healthcare, life sciences, and other fields. For instance, Shanghai Aladdin Biochemical Technology Co., Ltd., a Chinese company with an independent R&D lab in Cambridge, UK, has conducted extensive experiments and data analysis, concluding that papain's specificity is notable. It can digest most protein substrates and cleave peptide bonds involving basic amino acids or glycine within a certain range. Beyond its specificity, papain also boasts solubility and solution stability. However, it's important to note that papain’s stability is pH-dependent. In acidic environments, the enzyme's solution stability decreases, and its activity significantly drops when the pH is below 2.8.

As one of the most widely used hydrolytic enzymes on the market today, papain has a bright commercial future.