Tratamento, estabilização e aplicações dos co-produtos da unidade oatvita

Abstract

The OATVITA unit produces plant-based food ingredients that are represented in concentrated vegetable bases from different raw materials such as cereals, pseudo-cereals, legumes, tubers, or their combination. The co-products resulting from the production of these bases have a high-water activity and, therefore, a high microbiological risk. In this work, a thermal treatment and two drying methods were studied for the stabilization of the co-products of the vegetable bases of whole grain oat flour and oat bran Standard and Low Sugar. The drying methods used were freeze-drying and drying in a muffle/oven, which makes it possible to observe the differences caused by a conventional convective drying method at high temperature and another, more technologically advanced, at low temperatures. The stability of the co-products and the differences caused by the different treatments were evaluated through physical-chemical, microbiological, and organoleptic parameters with sensory analysis. Furthermore, to evaluate these differences and to demonstrate the commercial value of the co-products, several applications were also developed, which were analyzed sensorially. All co-products studied were stable during the eight weeks of study. Lyophilization proved to be the method that best preserves the characteristics of the co-products, however, through the sensory analysis performed, the drying method did not prove to be relevant for the applications developed. Additionally, drying in a muffle/oven (105 ºC) proved to be more effective in reducing enzymatic and possibly microbiological activity. Regarding the heat treatment applied, it was not always effective in reducing the microbiological or enzymatic load of the co-products, however this aspect does not preclude the future use of the products. Regarding the applications developed, there was no significant sensory impact caused by the different treatments used, however the presence of enzymatic activity in some of the co-products implies their suitability for the application to be developed. In the sense that it is not possible to develop products with high gluten content using co-products with high enzymatic activity.

Date of Award	9 May 2023
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Joana Mafalda Patrício de Oliveira Fernandes Inácio Ferreira (Supervisor) & Ana Brandão (Co-Supervisor)