If you’ve visited a trendy cafe in recent years, you may have noticed “golden” turmeric milk on the menu. Although recently touted as a healthy decaffeinated coffee alternative, the drink is a fanciful version of haldi doodh -? a traditional Indian drink often used as a home remedy for colds. And now, researchers have developed an effective method to make an herbal, instant version that preserves the beneficial properties of the ingredients while extending its shelf life.
The researchers will present their results at the fall meeting of the American Chemical Society (ACS). ACS Fall 2024 is a hybrid meeting held virtually and in person August 18-22. includes approximately 10,000 presentations on a range of scientific topics.
Golden milk -? also called gold or turmeric latte -? it consists of milk, turmeric and spices and is a good choice for people who want to avoid caffeine or coffee or maybe enjoy a unique taste. “It’s a really good drink, especially if it’s cold outside or if you’re sick,” explains Anthony Suryamiharja, a graduate student at the University of Georgia who is presenting the research at the meeting. It says that turmeric also has the bioactive compound curcumin -? a polyphenol that has been studied for its potential anti-inflammatory and antioxidant effects. “If we can incorporate bioactive compounds like curcumin into plant-based milks to bring them up to the same nutritional level as cow’s milk, why not?” asks Suryamiharja.
Curcumin, however, is difficult to separate from turmeric, and usually requires complex extraction techniques involving organic solvents, many days, and a lot of energy. Additionally, the compound tends to break down over time, reducing its lifespan. So, inspired by the golden milk, Suryamiharja, Hualu Zhou and colleagues wanted to investigate whether there was a way to extract and store curcumin in plant milk.
First they added turmeric powder to an alkaline solution, where the high pH made the curcumin more soluble and easier to extract than in plain water. This deep red solution was then added to a sample of soy milk, producing the dark yellow color. They brought it down to a neutral pH of around 7. Just like low pH acids, high pH bases are not the most pleasant things to consume. The neutralized pseudogolden milk could be enjoyed as is, but to further preserve it, the team removed the water from the solution via freeze-drying, producing an instant golden milk powder.
Not only does the method extract curcumin from turmeric more efficiently than existing methods, it also incorporates curcumin into oil droplets within the soy milk. This means that when consumed, our body recognizes curcumin as fat and assimilates it as such, theoretically making curcumin more bioavailable or likely to be absorbed and have an effect on the body. Encapsulating curcumin also protects it from air and water, preserving it and keeping it stable for longer.
While this work focused specifically on soy milk because of its high amino acid content, the researchers say it could be applied to other plant-based milks, providing options for those with soy allergies. Furthermore, the pH-based extraction method could be used on different plant compounds with similar ease and efficiency. For example, blueberries are rich in anthocyanins, another water-soluble polyphenol.
“When we use the same method, within about a minute we can extract the polyphenols,” Zhou explains. “We want to try to use that to recycle byproducts and reduce food waste from growing fruits and vegetables here in Georgia.”
Although more research is needed before their instant golden milk hits store shelves, the researchers’ initial results are promising. Suryamiharja reports that it tasted good, even though he doesn’t often enjoy golden lattes himself.
The team hopes that this work can help explain the chemistry behind what may seem like nothing more than a simple beverage, as well as improve the nutritional value and convenience of this beverage for those who enjoy it. Suryamiharja explains that “people usually do a lot of simple things in the kitchen, but they don’t really realize that there is a chemistry behind it. So, we try to explain these unspoken things in a simple way.”
The research received seed funding from the University of Georgia’s Department of Food Science and Technology.
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