Efetividade da infusão a frio na indústria de chás e derivados

Abstract

Tea is an ancient drink prepared by infusing branches of Camellia sinensis in hot water. Consumed worldwide, about 3 million tons of dry plant are produced annually. This popularity comes from the medicinal properties linked to its consumption. These, in turn, are related to the high levels of antioxidant compounds extracted from the plant during infusion. These benefits popularized not only tea but also the product of its fermentation in the presence of sugar: Kombucha. Tea fermentation occurs through a symbiotic culture of acetobacteria and yeast, known as Scoby, aerobically, preferably between 18 to 30°C, producing a slightly carbonated and acidic drink. When considering the use of hot water in the infusion for subsequent fermentation, it is possible to observe that there are large temperature variations involved in the process, which could be circumvented if the infusion occurred at the same temperature as the infusion. Through the bibliographical analysis, references were found that demonstrate good rates of extraction of antioxidant compounds from cold infusions, performed for at least 2 hours, compared to hot infusions of 15 minutes. With these results, a case study was proposed, comparing the increase in time imposed by cold infusion, and the energy expenditure that heating and cooling entailed for the process. With the calculations, it was possible to analyze that the hot process is not only more energetically expensive, but also takes an hour longer to be carried out, since it involves more steps in the process.