Analysing Biogenic Amines in Soy Sauce with the Help of Chromatography

Soy sauce is a condiment found in many kitchens across the globe. Its relatively simple ingredients belie a sophisticated manufacturing process that has been used for centuries. Whether it is used in cooking or on our crispy rolls, many people love soy sauce - but not all sauces are equal and some may potentially be harmful.

A recent study published in the journal Molecules has looked at the potential harmful ingredients in some soy sauces. The study - published under the title Comparison of Biogenic Amines in Chinese Commercial Soy Sauces - analysed a class of compounds called biogenic amines in 53 commercially available soy sauces using a new high-performance liquid chromatography method. They report that the work could help manufacturers control the concentrations of biogenic amines in the future.

What’s in the sauce

Soy sauce has been produced for several centuries using the same recipe - although the actual production techniques may have been automated for some sauces. For the past few centuries, naturally brewed soy sauce has been made from the same four ingredients: soybeans, wheat, salt and water. The process follows the same four steps.

1. Soybeans are soaked in water and steamed, wheat is roasted and crushed to aid fermentation ad the salt is dissolved in water.
2. A fungus is added to the soybeans and wheat to allow fermentation and the production of koji mash.
3. The salt and water mix is added to make a mixture known as moroni. This mix is fermented for several months to produce the taste and colour of soy sauce.
4. The soy sauce is then pressed from the Moroni mash, refined and packed ready to enjoy.

A study in soy

However, as mentioned above, all the fermentation can result in some compounds that are not necessarily healthy as each soy sauce manufacturer has his own process, conditions and additives to aid fermentation. One of the main culprits are biogenic amines. Biogenic amines are low molecular weight compounds that can be useful in determining the quality of soy sauce. They have beneficial roles to play in humans at low levels. But high concentrations of biogenic amines can be harmful.

In the study mentioned above, 53 samples of soy sauce were analysed for biogenic amines using a newly developed high-performance liquid chromatography technique. The development of HPLC methods is the topic of the article, Integration of MS and UV Data for Peak Tracking in HPLC Method Development.

The researchers detected ten main biogenic amines in most of the samples tested. But there were significant differences in the total concentrations of biogenic amines in the samples. Dark soy sauce had higher concentrations that light soy sauce, and there were differences between brands and geographical regions. The authors report that the study has given them a good basis to start studying the effects of production methods for the control of biogenic amines in the future.