Extração e modificação de proteína vegetal de Castanha-do-Brasil (Bertholletia excelsa) por técnicas não tradicionais

Abstract

Plant-based proteins can be consumed by different types of individuals, especially those who cannot consume protein of animal origin. The Brazil nut is a fruit extremely used for its nutritional qualities. Ways to improve protein concentration in foods have been studied in order to obtain promising results in its concentration. High intensity ultrasound technique is being used to extract proteins without the use of chemical substances in order to be a more sustainable alternative to the environment. This work aims to evaluate the effect of the conventional method and alternative method on the physicochemical properties of proteins isolated from Brazil nuts. Obtaining the Brazil nut degreasing cake was carried out using the conventional press method. Then, the sample was extracted by pH difference to reach the protein isolate (method 1), by ultrasound extraction (method 2) and combined extraction (method 3). This is an experimental study with a quantitative approach, where Brazil nut protein isolate was used to analyze the chemical composition (moisture, ash, protein, lipids and carbohydrates), physical properties (solubility, absorption capacity of water and oil and foam formation and stability) and antioxidant activity carried out in triplicates in the analytical center of IFAM-CMC, Manaus/AM. With the results obtained, it was observed that the sample extracted by the method 1 presented a high moisture content (41.53%), ash (0.667) and lipids (23.5%), and yet, among the three samples analyzed, stood out in protein concentration (16.09%), indicating that the use of protein isolate can be an excellent vegetable protein option, contributing to the promotion of health and environmental sustainability. Regarding the sample treated with ultrasound (method 2), a low ash (0.0032%) and lipid (16.72%) content was noted. In the physical properties of the extracted protein, the method 3 presented 17.70% of soluble nitrogen, being the highest solubility compared to the types of extraction studied, in the water and oil absorption capacity, the sample extracted by ultrasound was highlighted (232%) and 87.64%, respectively. In foam formation/stability, the sample extracted by the combined method formed a larger volume of foam and kept it stable for a longer time. Furthermore, an antioxidant effect of the protein isolate generated from immersion in sonification can be observed. Ultrasound-assisted extraction is a promising technique for the food technology sector, it has low environmental impact, lower energy and solvent consumption, and is in line with green chemistry technology and sustainable concepts.