Introduction to Kosher Enzymes (Part 2): What Are the Sources of Enzymes?

What are the sources of enzymes?

Food-industry enzymes mainly have three sources - animal, plant and microbial. Currently there are three main classes of animal-derived food enzymes. Rennet is extracted from the fourth stomach of a cow, rich in enzymes such as chymosin and pepsin. These enzymes are all proteases that can cause milk to coagulate into cheese. Lipase, by breaking down part of the fat, turns oils into butter; it can also accelerate cheese ripening (enzyme-modified cheese). The use of rennet is discussed in the Talmud and has also sparked various discussions. Historically, only rennet from Kosher-slaughtered cows was considered Kosher. Authoritative rabbis have thoroughly explored its use based on the Jewish rules of not eating meat and dairy together, because there were many views on the practice of extracting rennet from non-Kosher animals. Likewise, lipase from non-Kosher animals is also forbidden.

Another enzyme from animals applied in the food industry is pancreatin, obtained by dehydrating the pancreatic tissue of an animal - usually a pig. Pancreatin is rich in various proteases that can denature protein for easy digestion. Another enzyme with the same action is trypsin. The formulas of Mead Johnson, Abbott and Nestle infant formula all use pancreatic tissue and its derivatives to break down protein and promote children's digestion and absorption. Many health foods claiming to improve muscle mass also contain these components.

Note: although these infant formulas are not Kosher-certified, their content of non-Kosher enzymes is very low. If a doctor recommends using such products, we should consult an authoritative rabbi.

Currently there are mainly three plant-source proteases used commercially - papain from the papaya plant, bromelain from the pineapple plant, and ficin from the fig. Papain and bromelain are mainly used as meat tenderizers, while ficin's use is limited by its more active hydrolytic activity. In addition, barley amylase is also used to make malt syrup.

The recent wave of attention to enzymes is mainly caused by their third source - microorganisms. Cultivating microorganisms on a nutrient medium causes them to produce various enzymes during growth to complete normal metabolism - this process is usually called fermentation. For example, in order to grow on starch, yeast must first secrete a series of amylases to convert starch into sugar so it can digest it. If people can control the growth of microorganisms and collect the enzymes after they secrete enough of what is needed, they can be applied elsewhere. This is the core technology of producing enzymes through fermentation.

The microorganisms (bacteria, fungi and yeast) in the fermentation process occur naturally. Until recently, the way to produce enzymes with microorganisms was limited to finding and individually cultivating those microorganisms that could produce large amounts of a specific enzyme under suitable conditions. Over the years, many such microorganisms have been found and individually cultivated, some of which are natural mutants of others. People found that some variants are more powerful at producing enzymes, so they found them for reproduction. New mutants can also be formed by controlling the chemical or physical environment of microorganisms. Enzyme-making companies now all have such microorganism libraries and are constantly working to improve their performance.

A more recent development is owed to gene recombination technology, commonly known as cloning. One method is to figure out the genetic code that determines a certain microorganism's ability to produce the desired enzyme, and then repeatedly copy this code in the organism. This way, the organism's enzyme-producing performance is several times higher than that of an ordinary organism. In addition, scientists have now also found that implanting the genetic code obtained from one organism into a completely different microorganism in nature enables that microorganism to produce enzymes (or other chemicals) it could not originally synthesize. The transplanted organism does not exist in nature, but is an organic living organism with unique performance.

The best example using these two methods is "microbial rennet." Rennet, as mentioned earlier, is a protease from a cow's stomach, mainly used in the food industry to break down protein molecules in milk to coagulate it into cheese. Because animal-source rennet is limited, scientists worked to find a protease with a similar function. Later they found several microorganisms that can produce proteases similar (but not identical) in function to rennet under suitable conditions. These are precisely the "microbial rennet" we use to make Kosher cheese. Several commonly used microorganisms are Mucor mehei, Mucor pussilus lindt, and Endothia parastica, with corresponding enzymes "Fromase," "Emporase" and "SureCurd." One problem with these products is that their chemical properties are not completely identical to rennet, so their functions differ slightly. In addition, they produce other enzymes, giving cheese an off-flavor. Some companies now produce genetically modified microorganisms that can produce true rennet, such as Chymax genetically modified from E. coli, Chymogen genetically modified from Aspergillus niger, and Maxiren genetically modified from yeast. Whether these genetically engineered rennets are superior or inferior to traditional microbial rennet is undetermined, but it is highly significant.