Estudo da conservação mínima para as folhas da mandioqueira (manihot esculenta) e da obtenção de concentrados protéicos por três vias químicas

Abstract

Cassava is a raw material with remarkable role in the national agricultural scenario, which generates employment and income in all regions of the country. The use of this agricultural product is integral, due to its great versatility. The root is used for food, animal feed and for the flour, starch and energy industries; the aerial part (leaves and stems) can be used for human food (flour from the leaf) and animal feed. In this context, the aim of this thesis was to evaluate the potential products derived from the leaves of mandioqueira root, in order to versify its use as well as to promote the valuation of this fraction in the raw material. The first chapter of the thesis presents a literature review, which portrays the subjects that are raised in the following chapters. Chapters from II to VI present the experimental data obtained in this research. In the second chapter, it was evaluated the use of leaves as a minimally processed product for transport, as well as its storage under controlled conditions of temperature and atmosphere. In the third chapter, it was studied the chemical composition, physicochemical properties and proteins fractionation of the leaves from the raw material (Manihot esculenta), based on the Osborne procedure, where different solvents were applied to fractionate the proteins through changes in solubility that these protein leaves present. From this, it was performed in chapters IV, V and VI, the extraction of proteins, applying three different chemical pathways to obtain concentrate. These conditions allowed the development of the second and third manuscripts. For the extraction process, there were used: factorial design (BoxBehnken), response surface methodology, and the desirability function, which were applied to define the optimal conditions for the proteins of mandioqueira, in all routes (extraction by organic solvent, extraction under acid conditions and extraction under alkaline conditions). The lyophilized protein concentrates obtained in the three pathways were characterized. The total phenolic contents, total flavanols, chlorophyll a,chlorophyll b, and total carotenoids were determined; the colorimetric parameters were performed. Crude protein content, protein extraction yield and protein concentrate yield were quantified. Technological properties of this concentrate were determined through water absorption capacity and oil absorption capacity. The evaluation of these responses allowed the definition of the optimum process condition for each route of extraction, by the desirability function. Consequently, a monitoring of the extraction process was made, which was considered a process in permanent regime, presenting four stages: two inlet (fresh leaf and extraction solution) and two outlet (fibrous residue and lyophilized protein concentrate); whose control was possible by recording the mass (g), dry matter (g/100 g), crude protein (g dry basis) and moisture (%). The three lyophilized protein concentrates derived from the conditions of desirability were evaluated hygroscopically, by means of moisture sorption isotherms at 25 ºC. The studies carried out with mandioqueira are promising, because from them, it was possible to deepen forms of production and transformation of this raw material; factors that can influence directly or indirectly and positively in the social dimensions, environmental, cultural and economic of the region, and consequently promote the valorization of a regional raw material, either by trying to popularize other forms of use or by deepening knowledge about it.