Estudo da adição de suspensão coloidal de celulose vegetal e vitamina C em iogurtes

Abstract

Milk and its derivatives have a variety of essential components that constitute a food with high nutritional value. However, even though they are rich in essential nutrients, they are reportedly low in fiber and vitamin C. The enrichment with ingredients that supply these deficiencies contributes to the formation of a healthy food and meets specific market requirements. To understand the processes involved in the fortification of dairy products with vitamin C, an overview of the structure and stability of this vitamin is presented in Chapter 1, followed by an experimental section that includes the development of an analytical method for the quantification of ascorbic acid by high performance liquid chromatography with UV-Vis detection and a kinetic study of this vitamin in yogurt as the dairy matrix of interest. The phenomenon of browning is evaluated by identifying markers of the Maillard reaction and colorimetric assays, the objective was to determine whether the potentiation of browning in the presence of vitamin C occurs via a non-enzymatic reaction or via the ascorbic acid degradation pathway. A loss of vitamin C content of approximately 77% was observed after 21 days of production, in addition to the potentiation of browning as a function of the heat treatment applied. Chapter 2 presents a new approach to the yogurt matrix: the addition of colloidal suspension of vegetable cellulose. The presented work evaluates the physicochemical parameters of yogurts prepared with the addition of cellulose fibers and aims to discuss the techno-functional properties due to the presence of different types of vegetable cellulose. Therefore, it is possible to observe advantages in terms of stability of the final product due to the presence of cellulose fibers. This project combines a technological discussion of industrial interest regarding the stability of vitamin C and an innovative application of academic interest using laboratory-scale plant cellulose fibers.