Effect of pre-treatments and post-treatments on drying products

Freeze drying technology can give good quality attributes of vegetables and fruits in terms of color, nutrition, volume, rehydration kinetics, stability during storage, among others, when compared with solely air dried ones. However, published scientific works showed that treatments applied before and after air dehydration are effective in food attributes, improving its quality. Therefore, the hypothesis of the present thesis was focus in a vast research of scientific work that showed the possibility to apply a pre-treatment and a post-treatment to food products combined with conventional air drying aiming being close, or even better, to the quality that a freeze dried product can give. Such attributes are the enzymatic inactivation, stability during storage, drying and rehydration kinetics, color, nutrition, volume and texture/structure. With regard to pre-treatments, the ones studied along the present work were: water blanching, steam blanching, ultrasound, freezing, high pressure and osmotic dehydration. High electric pulsed field was also studied but the food attributes were not explained on detailed. Basically, water and steam blanching showed to be adequate to inactivate enzymes in order to prevent enzymatic browning and preserve the product quality during long storage periods. With regard to ultrasound pre-treatment the published results pointed that ultrasound is an effective pre-treatment to reduce further drying times, improve rehydration kinetics and color retention. On the other hand, studies showed that ultrasound allow sugars losses and, in some cases, can lead to cell disruption. For freezing pre-treatment an overall conclusion was difficult to draw for some food attributes, since, each fruit or vegetable is unique and freezing comprises a lot of variables. However, for the studied cases, freezing showed to be a pre-treatment able to enhance rehydration kinetics and color attributes. High pressure pre-treatment showed to inactivate enzymes improving storage stability of food and showed to have a positive performance in terms of rehydration. For other attributes, when high pressure technology was applied, the literature showed divergent results according with the crops used. Finally, osmotic dehydration has been widely used in food processing to incorporate a desired salt or sugar present in aqueous solution into the cellular structure of food matrix (improvement of nutrition attribute). Moreover, osmotic dehydration lead to shorter drying times and the impregnation of solutes during osmose allow cellular strengthens of food. In case of post-treatments, puffing and a new technology denominated as instant controlled pressure drop (DIC) were reported in the literature as treatments able to improve diverse Abstract Effect of Pre-treatments and Post-treatments on Drying Products x food attributes. Basically, both technologies are similar where the product is submitted to a high pressure step and the process can make use of different heating mediums such as CO2, steam, air and N2. However, there exist a significant difference related with the final stage of both which can comprise the quality of the final product. On the other hand, puffing and DIC are used to expand cellular tissues improving the volume of food samples, helping in rehydration kinetics as posterior procedure, among others. The effectiveness of such pre and/or post-treatments is dependent on the state of the vegetables and fruits used which are also dependent of its cellular structure, variety, origin, state (fresh, ripe, raw), harvesting conditions, etc. In conclusion, as it was seen in the open literature, the application of pre-treatments and post-treatments coupled with a conventional air dehydration aim to give dehydrated food products with similar quality of freeze dried ones. Along the present Master thesis the experimental data was removed due to confidential reasons of the company Unilever R&D Vlaardingen

Regulação do comportamento alimentar e novos alvos terapêuticos

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

A alfarroba como fonte de ingredientes bioactivos: fibra alimentar, polifenóis e ciclitóis

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

O Papel da Linderança sobre a Intelig~encia Emocional. Aplicação no Sector de Retalho Alimentar (Grupo MaxiCompra)

A globalização e competitividade do presente século a nível organizacional, exige uma melhoria contínua, do seu capital humano, de forma a conseguirem garantir o seu crescimento e sobrevivência a longo prazo. Os novos líderes do século XXI denotam elevada protuberância na gestão do capital humano das organizações. Os líderes dotados de inteligência emocional, elevam o potencial dos seus liderados e permitem criar um ambiente ressonante entre os elementos da sua equipa. Um líder que consiga ser emocionalmente inteligente, gera empatia entre os seus liderados, criando laços fortes de pertença entre si e a sua equipa, conseguindo então libertar, o maior potencial dos seus liderados, tornando-os mais competentes e eficazes, no alcance de objectivos em prol da organização. O líder com inteligência emocional, é o novo tipo de líder desejado, neste clima conturbado que atravessamos. A presente dissertação, centra-se em temas relacionados com Liderança, Tipos de Liderança, Inteligência Emocional, Equipas, e Eficácia de Equipas. Com base na pesquisa bibliográfica e empírica realizada em uma organização, que envolve líderes e liderados, procura-se compreender se o tipo de liderança aplicada influencia a inteligência emocional dos liderados e por sua vez se a inteligência emocional dos liderados influencia a eficácia das equipas de trabalho.

Alergia Alimentar na Restauração

O Manual de Alergia Alimentar para a Restauração foi criado com o objetivo de informar, educar e ajudar os setores da restauração, hotelaria e turismo a lidar com a alergia alimentar e com as novas disposições previstas no regulamento 1169/2011 da União Europeia. O presente manual inclui assim componentes educacionais e práticas na abordagem à alergia alimentar na restauração, não tendo caráter vinculativo ou legal, nem substituindo a abordagem médica ou nutricional no diagnóstico e tratamento da doença. A informação disponível relativamente à presença de alergénios nos alimentos processados e preparações culinárias é exemplificativa, permitindo a adaptação ao desenvolvimento de novos géneros alimentícios e receitas culinárias. Todos os contributos e informações adicionais poderão assim ser remetidos para o Centro de Competências de Alergia Alimentar da Universidade do Porto, de forma a contribuir para a melhoria contínua do manual e dos serviços prestados pela restauração aos clientes com alergia alimentar.