Enzyme Synthesis from Kitchen By-Products: A Pathway to Sustainable Bio-Shampoos

Every day, households around the world generate a steady stream of organic waste: fruit peels, vegetable scraps, and leftover food. When this material is thrown into a landfill, it often sits in a pile where air cannot reach it. In these airless conditions, the waste breaks down and releases methane, a gas that traps heat in the atmosphere far more effectively than carbon dioxide. This process contributes significantly to climate change. At the same time, the global population continues to grow, demanding more resources and producing more waste than the planet can easily absorb. Scientists and engineers are constantly searching for ways to turn this problem into a solution, looking for methods that can transform trash into something useful while reducing the environmental burden. One such method involves fermentation, a natural process where microorganisms break down organic matter. By guiding this process, it is possible to create a liquid rich in beneficial enzymes and organic acids, known as garbage enzyme. This substance has shown promise as a cleaning agent and a way to reduce the harmful gases produced by rotting waste.

A recent study conducted by a researcher at the VNU-HCM High School for the Gifted in Vietnam explores how to make this garbage enzyme most effectively and how to use it to create a sustainable shampoo. The goal was to find the perfect recipe for fermenting kitchen scraps and then test whether the resulting liquid could clean hair as well as it cleans surfaces. The researcher started by mixing organic waste with sugar and water in sealed containers. The standard recipe used a specific ratio: one part sugar, three parts waste, and ten parts water. To see if the type of sugar or the way the waste was prepared mattered, the researcher set up several different batches. Some used white granulated sugar, while others used molasses, a thick, dark syrup. Some batches contained kitchen waste left in large chunks, while others contained waste that had been chopped into smaller pieces. Crucially, the researcher also tested whether adding a specific microbial preparation, a substance containing helpful bacteria and fungi called Emzeo, would speed up the process.

The initial tests, which did not include the microbial preparation, showed little sign of fermentation after a month. The mixtures did not develop the characteristic sour smell or the white fungal growth that indicates the process is working. This suggested that without the right starter culture, the kitchen waste alone was not fermenting efficiently. When the researcher added the Emzeo preparation to the mixtures, the results changed dramatically. Among the various combinations, one specific batch stood out as the most successful. This winning mixture consisted of 25 milliliters of molasses, 75 grams of kitchen waste that had been cut into medium pieces, and 250 milliliters of water, all supplemented with 0.2 grams of the Emzeo preparation. After 30 days of incubation, this batch produced a liquid with a pleasant, sweet-and-sour yeast smell. The surface of the liquid was covered by a thick, uniform layer of white microbial growth, and the solid waste at the bottom had completely broken down. In contrast, other batches either smelled unpleasant, had thin layers of growth, or left the waste largely intact.

With the optimal recipe identified, the researcher moved on to test the cleaning power of the resulting enzyme solution. The liquid was applied to three different types of surfaces and used to remove three different kinds of stains. In every case, the enzyme solution successfully removed the stains completely. Encouraged by this result, the researcher then formulated a shampoo using this homemade enzyme. The final product was designed to be gentle and free from harsh chemicals, specifically avoiding sulfates, which are common in commercial shampoos but can be irritating to the scalp and harmful to the environment. The resulting bio-shampoo had a stable pH level of 5.5, which is close to the natural acidity of human skin and hair. It foamed well and cleaned effectively without being harsh. The formulation relied entirely on natural herbal ingredients combined with the synthesized enzyme, offering a non-toxic alternative to conventional hair care products.

The study concludes that turning kitchen waste into a useful cleaning product is not only possible but can be optimized with a simple, specific recipe. By using chopped organic waste, molasses, water, and a small amount of microbial starter, it is possible to create a powerful enzyme solution in just one month. This solution works as a cleaner and can be the base for a sustainable shampoo that is safe for both people and the planet. While the research has not yet tested how long the product lasts on a shelf or explored every possible type of stain, the findings provide a clear path forward. They demonstrate that a common household problem—food waste—can be transformed into a resource that helps reduce greenhouse gas emissions and offers a greener alternative for daily personal care.