Evaluation of the nutritional and functional properties during processing of edible drink in the highlands of Ecuador

In the high, thin air of the Andes, where the sun is fierce and the nights are cold, maize is more than just a crop; it is a lifeline. For thousands of years, people in these high-altitude regions of Ecuador have grown this grain, adapting it to survive conditions that would choke other plants. While maize is known globally as a source of energy, providing the starch that fuels our bodies, it also carries a hidden potential within its kernels. Depending on the color of the grain, the plant contains different natural compounds that can act as antioxidants, helping to protect the body from damage. In recent decades, scientists have learned that how we process food—whether we let it sprout, cook it, or let it ferment—can change these nutritional properties significantly. This is particularly true for traditional fermented drinks, where the action of microbes transforms simple sugars into complex flavors and potentially beneficial substances. Understanding these changes is not just about preserving tradition; it is about finding new ways to improve nutrition and create value for the farmers who grow these unique varieties.

A team of researchers from Ecuador and South Korea set out to explore this potential by looking at five specific types of maize developed for the highlands. These varieties, created by the National Institute of Agricultural Research in Ecuador, differ in color and texture, ranging from white and yellow to a deep black-purple. The scientists wanted to see what happens to the nutritional makeup of these grains as they move through three distinct stages: first as raw kernels, then after they have been allowed to sprout, and finally after they have been turned into a traditional fermented beverage known as chicha. The goal was to determine if the processing steps helped or hurt the beneficial compounds, and which variety of maize might be the best candidate for creating a healthy, functional drink.

The journey began in the laboratory with the raw grains. The researchers measured the physical traits of each variety, noting that the white, floury kernels were the largest and heaviest, while the yellow, sweet kernels were the smallest. They also analyzed the color of the grains using a sensitive instrument that measures lightness and hue. As expected, the black-purple variety was the darkest, while the yellow and white grains were much brighter. This color difference is significant because it hints at the presence of different natural pigments, such as the yellow carotenoids found in the bright grains and the purple anthocyanins found in the dark ones. These pigments are often linked to health benefits, acting as antioxidants that neutralize harmful molecules in the body.

Next, the team took the grains and allowed them to germinate. This process involves soaking the seeds in water and letting them sit in a warm environment until they begin to grow. During this stage, the seeds wake up and start to break down their stored energy to fuel the new plant. The researchers found that this sprouting process changed the chemical landscape of the grains. In almost every variety, the amount of sugar increased as the starch was broken down into simpler forms. More importantly, the sprouting triggered a rise in polyphenols, a broad group of plant compounds known for their antioxidant properties. The ability of the grains to fight oxidation also improved across the board. However, the results were not uniform; the dark purple variety saw a slight drop in its anthocyanin content during sprouting, likely because these delicate compounds are sensitive to the changes happening inside the seed. Meanwhile, one of the yellow varieties showed a marked increase in carotenoids, suggesting that the sprouting process can boost specific nutrients depending on the genetic makeup of the grain.

The final stage of the experiment involved turning the sprouted grain into a beverage. The researchers mixed the ground, sprouted maize with water and let it ferment for two days at room temperature. This is the traditional method for making chicha, a drink that has been part of the diet in the Andes for centuries. As the mixture fermented, the environment changed rapidly. The acidity of the liquid increased, and the pH dropped, creating an environment where beneficial bacteria and yeast could thrive. The researchers tracked these changes daily, observing that the sugar levels fluctuated as the microbes consumed them. When they analyzed the final drink, they found that the fermentation process generally reduced the overall antioxidant activity compared to the sprouted grain. This suggests that the microbes or the chemical conditions of fermentation may break down some of the beneficial compounds. However, there was a notable exception. The dark purple variety, INIAP 199, retained a very high level of polyphenols even after fermentation, standing out from the other four varieties.

The study did not stop at chemical analysis; it also asked people what they thought of the drinks. A panel of forty people, including locals and researchers, tasted the chicha made from each of the five maize varieties. They rated the drinks on color, smell, taste, and texture. The results were striking. The drink made from the dark purple maize received the highest scores for color and overall quality. The panelists clearly preferred the deep, rich hue of the purple variety. In contrast, the drink made from the white maize variety received the lowest scores across the board, particularly for smell and taste. This preference for the dark variety aligns with the chemical findings, as the purple grain not only looked the most appealing but also contained the highest levels of the health-promoting compounds that survived the fermentation process.

The researchers concluded that the choice of maize variety is critical when developing functional foods. While sprouting generally boosts the nutritional value of the grain by increasing sugars and antioxidants, the subsequent fermentation step can alter these benefits. The study suggests that not all maize is created equal in this regard. The dark purple variety, INIAP 199, emerged as a standout, offering a unique combination of high antioxidant content and strong consumer appeal. This finding points toward a specific strategy for farmers and food producers: by selecting the right variety and understanding how it reacts to processing, it is possible to create traditional products that are both delicious and nutritionally superior. The work highlights that the genetic diversity of maize in the Ecuadorian highlands holds untapped potential for improving human health and supporting local economies, provided that the processing methods are tailored to preserve the unique qualities of each grain.