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Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para obtenção do Grau de Mestre em Inovação e Qualidade na Produção Alimentar

Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para obtenção do Grau de Mestre em Inovação e Qualidade na Produção Alimentar

Relatório do Trabalho de Fim de Curso de Engenharia Biológica e Alimentar apresentado na Escola Superior Agrária do Instituto Politécnico de Castelo Branco.

O figo-da-índia é constituído maioritariamente por água (84-90 %) e açúcares (10-15 %), predominantemente glucose e frutose. Além disso, devido ao seu conteúdo em proteínas, fibras, minerais, vitamina C, β-caroteno, niacina, riboflavina e tiamina, este fruto tem sido considerado com elevado interesse nutricional, bem como reportadas algumas atividades biológicas. Neste contexto e dado as propriedades sobejamente conhecidas dos benefícios do iogurte, pretendeu-se desenvolver um iogurte e uma gelatina de iogurte, com polpa de figo-da-índia. A polpa foi fornecida pela Associação do Figo da Índia da Beira Baixa (AFIBB) e os iogurtes foram desenvolvidos nos laboratórios da Schreiber Foods Portugal, S.A. Foram testadas várias formulações para o desenvolvimento dos iogurtes, tendo-se selecionado para produtos finais duas gelatinas de iogurte e dois iogurtes tipo grego: a) gelatina de iogurte 0 % de matéria gorda com 5 % de polpa de figo-da-índia e aroma de manga; b) gelatina de iogurte 0 % de matéria gorda com 2,5 % de polpa de figo-da-índia e preparado de ananás maracujá; c) iogurte tipo grego bicamada com 8 % de polpa de figo-da-índia; d) iogurte tipo grego batido com 8 % de polpa de figo-da-índia. Foram realizados estudos de tempo de vida nos iogurtes desenvolvidos ao longo de 52 dias, para os parâmetros pH, textura e força gel. As amostras foram analisadas no 1º, 3º, 7º, 15º, 23º, 30º, 40º e 52º dias após produção. Os resultados dos estudos de tempo de vida foram submetidos a uma análise de variância a dois fatores (tipo de iogurte e dias de armazenamento). Estes resultados indicam que existem diferenças significativas (p<0,05) para pH, textura e força gel entre os iogurtes. Os produtos finais foram submetidos a testes de aceitabilidade e obteve-se uma avaliação positiva para os 4 produtos desenvolvidos. A gelatina de iogurte de figo-da-índia com aroma de manga e o iogurte grego de figo-da-índia em bicamada foram os mais apreciados. Com base nos parâmetros físico-químicos, o tempo de vida estimado para os produtos desenvolvidos foi de 35 dias.

Disponível na Biblioteca da ESACB na cota C30-29420TFCPANH.

During the ageing process of wine spirits several phenomena occur, which are responsible for the final quality of the beverage. This work aimed to discriminate the aged wine spirits according to the wood species, ageing technology and ageing time using FT-Raman methodology. For this purpose, the same Lourinhã wine distillate aged in 250-L wooden barrels of Limousin oak wood (L) and chestnut wood (C) separately and used together (L + C), was monitored through FT-Raman during the first 12 months of ageing. This technique was also applied to the same wine distillate aged in stainless steel tanks with staves of the same kinds of wood and during the same period. FT-Raman allows separating the wine spirits according to the different wood species and ageing time. This technique seems to be a promising tool to monitor the ageing process of wine spirit through different technologies.

Screening of different ageing technologies of wine spirit by application of Near-Infrared (NIR) Spectroscopy and volatile quantification.

Fourier transform infrared spectroscopy (FTIR) with Attenuated Total Reflection (ATR) combined with functional data analysis (FDA) was applied to differentiate aged wine spirits according to the ageing technology (traditional using 250 L wooden barrels versus alternative using micro-oxygenation and wood staves applied in 1000 L stainless steel tanks), the wood species used (chestnut and oak), and the ageing time (6, 12, and 18 months). For this purpose, several features of the wine spirits were examined: chromatic characteristics resulting from the CIELab method, total phenolic index, concentrations of furfural, ellagic acid, vanillin, and coniferaldehyde, and total content of low molecular weight phenolic compounds determined by HPLC. FDA applied to spectral data highlighted the differentiation between all groups of samples, confirming the differentiation observed with the analytical parameters measured. All samples in the test set were differentiated and correctly assigned to the aged wine spirits by FDA. The FTIR-ATR spectroscopy combined with FDA is a powerful methodology to discriminate wine spirits resulting from different ageing technologies.

Near-infrared spectroscopic (NIR) technique was used, for the first time, to predict volatile phenols content, namely guaiacol, 4-methyl-guaiacol, eugenol, syringol, 4-methyl-syringol and 4- allyl-syringol, of aged wine spirits (AWS). This study aimed to develop calibration models for the volatile phenol’s quantification in AWS, by NIR, faster and without sample preparation. Partial least square regression (PLS-R) models were developed with NIR spectra in the near-IR region (12,500–4000 cm−1 ) and those obtained from GC-FID quantification after liquid-liquid extraction. In the PLS-R developed method, cross-validation with 50% of the samples along a validation test set with 50% of the remaining samples. The final calibration was performed with 100% of the data. PLS-R models with a good accuracy were obtained for guaiacol (r2 = 96.34; RPD = 5.23), 4-methyl-guaiacol (r2 = 96.1; RPD = 5.07), eugenol (r2 = 96.06; RPD = 5.04), syringol (r2 = 97.32; RPD = 6.11), 4-methylsyringol (r2 = 95.79; RPD = 4.88) and 4-allyl-syringol (r2 = 95.97; RPD = 4.98). These results reveal that NIR is a valuable technique for the quality control of wine spirits and to predict the volatile phenols content, which contributes to the sensory quality of the spirit beverages.

Arbutus unedo spirit is a valuable product in Mediterranean countries. This spirit is usually marketed in Portugal without wood ageing. This work aims to characterize the ageing effect on the Arbutus unedo spirit, for three and six months with oak wood (Quercus robur L.) submitted to different toasting levels, based on its chemical composition and its sensory properties. For this purpose, several parameters were analysed: acidity, pH, dry extract, and volatile compounds (methanol, acetaldehyde, ethyl acetate and fusel alcohols). The volatile compounds were identified by GC-MS and quantified by GC-FID. Sensory analysis was performed by a trained panel, who have profiled this beverage, as well as the changes acquired during ageing. Spectroscopic techniques, namely FTIR–ATR, were applied to discriminate the different beverages produced. The results highlighted an increase in Arbutus unedo spirit’s quality with the wood contact, mainly based on the sensory attributes. Additionally, they showed that the best beverages were produced using oak wood with medium toasting levels during three months of ageing

Many species of the so-called exotic plants coexist with native species in a balanced way, but others thrive very quickly and escape human control, becoming harmful—these are called invasive alien species. In addition to overcoming geographic barriers, these species can defeat biotic and abiotic barriers, maintaining stable populations. Ailanthus altissima is no exception; it is disseminated worldwide and is considered high risk due to its easy propagation and resistance to external environmental factors. Currently, it has no particular use other than ornamental, even though it is used to treat epilepsy, diarrhea, asthma, ophthalmic diseases, and seborrhoea in Chinese medicine. Considering its rich composition in alkaloids, terpenoids, sterols, and flavonoids, doubtlessly, its use in medicine or other fields can be maximised. This review will focus on the knowledge of the chemical composition and the discovery of the biological properties of A. altissima to understand this plant better and maximise its possible use for purposes such as medicine, pharmacy, or the food industry. Methods for the extraction and detection to know the chemical composition will also be discussed in detail.