Levedura selvagem: Comparação e análise de contaminação do processo fermentativo para obtenção de etanol de cana-de-açúcar

Abstract

The production of ethanol from sugarcane plays a crucial role in the biofuel sector, promoting the reduction of greenhouse gas emissions and energy sustainability. However, the presence of wild yeasts during the fermentation process can result in contamination and negatively impact the efficiency and quality of the produced ethanol. In this regard, the issue that inspired this study was presented through the following question: What are the distinct paths in the process of obtaining ethanol from sugarcane that can facilitate the entry of wild yeast, and what improvements can be identified for a good performance of the fermentation cycle? Therefore, the objective is to find efficient solutions for the control and prevention of this contamination, aiming to enhance the quality and profitability of the ethanol production process. The study was conducted through field research and compilation of laboratory data at a bioenergy plant in Goiás, over a three-month period of crop monitoring. The process stages were analyzed, from sugarcane reception to juice treatment, with a focus on contamination by wild yeasts. The importance of proper yeast selection and asepsis to ensure ethanol quality was also evaluated. The results showed that appropriate yeast selection plays a fundamental role in fermentation. Different yeast strains exhibit distinct characteristics, such as stress tolerance and sugar conversion efficiency, making it essential to choose a lineage that meets the specific requirements of the plant. Furthermore, proper asepsis through equipment cleaning and sterilization is crucial to avoid contamination by wild yeasts, which can compromise fermentation and reduce process efficiency. Comparative analysis of production years revealed the benefits of quality fermentation, free from flocculation and contamination by wild yeasts. Efficient fermentation leads to better utilization of sugars in the must, contributing to increased ethanol production. On the other hand, the presence of flocculation and contamination by wild yeasts can cause significant losses in production and process efficiency. Therefore, it is essential to implement appropriate practices for yeast selection, asepsis, and fermentation control to maximize process efficiency and obtain high-quality ethanol. Investing in careful yeast selection and maintaining proper sanitary conditions brings significant benefits, such as increased productivity, reduced raw material loss, and improved quality of the final product. By achieving quality fermentation, free from flocculation and contamination by wild yeasts, ethanol plants in Goiás can positively contribute to the biofuel industry.