Quantificação do ião cálcio nas uvas e vinhos brancos por espectroscopia de infravermelho

Com o objetivo de diminuir a incidência das leveduras encapsulas em alginato se aglomerarem na segunda fermentação em garrafa e reduzir custos associados à sua eliminação, pretendeu-se utilizar a metodologia NIR para determinar a quantidade de cálcio no vinho. Foram quantificados outros minerais para avaliar hipotéticos antagonismos iónicos. Observou-se também que este controlo de qualidade poderá ser efetuado no mosto. Atualmente este controlo é realizado por metodologias de análise de referência bastante morosas como EAA. Contudo a metodologia NIR demonstrou ser uma boa alternativa no controlo dos parâ-metros de qualidade na produção de vinho espumante, permitindo a diminuição do tempo de análise e de resíduos. No desenvolvimento dos modelos matemáticos para a calibração do NIR utilizaram-se 79 vinhos brancos e 60 amostras de mosto. Foram desenvolvidos 11 modelos de calibração onde o coeficiente de correlação foi, em aproximadamente 58% dos casos, maior que 0,99; ABSTRACT: In order to reduce the incidence of alginate beads aggregation during the second fermentation in the bottle and to reduce costs associated with their disposal, it was used the NIR technology to quantify calcium content in the wine. Other minerals were also quantified in order to evaluate possible ionic antagonisms. Quality control is usually done in the base wine but it can also be evaluated in the must. Currently this control was carried out by reference analysis methodologies generally rather slow as AAS. However NIR proved to be a good alternative technique in the control of quality parameters of wine production, allowing the reduction of the analysis time and waste. In order to develop mathematical models for the calibration of NIR it was used 79 white wine samples and 60 must samples. Eleven calibration models have been developed, where the correlation coeffi-cient was, in approximately 58% of cases, greater than 0,99

Evaluation of the evolution of the anthocyanins profile in red wine grape varieties in Alentejo

The flavonoids (including anthocyanins) are wine compounds with important anti-oxidant activity, protecting the cells against oxidative processes, preventing cardiovascular and neurodegenerative diseases, cancer, among others (Antoniolli et al. 2015; Castañeda-Ovando et al. 2009; Hosu et al. 2014; Huang et al. 2009; Kong et al. 2003). Anthocyanins in grapes at harvest are determinant to red wine quality and their development in the grape must be characterised in order to determine the most suitable date for the harvest. Thus the aim of this research is the evaluation of anthocyanins composition in two red wine grape varieties from véraison continuing through ripening. Anthocyanins were quantified by high resolution liquid chromatography (HPLC-DAD). Additionally, the total phenols content were quantified by UV-Vis Spectrometry. The anthocyanins’ profile evolution may be dependent on the variety and ripening phase. During ripening grape samples have shown an increase of coumaryl derivatives. This information may lead us to understand the anthocyanins biosynthesis pathway in different grape varieties. The development of anthocyanins from the véraison seems to follow a pattern that coincides with the increasing accumulation of soluble sugars

ADDITION OF VINEGAR TO EXTEND THE SHELF-LIFE OF CABEÇA DE XARA

Cabeça de xara is a ready-to-eat meat product, whose production is very characteristic in Alentejo, a particular region of Portugal. It is a galantine usually moulded into parallelepiped shape made with various meats obtained from the Alentejano pig breed reared in the same region, namely deboned pork heads, tongue and connective tissue to which a number of condiments like salt, parsley, wine and pepper, are added. This work intended to test the feasibility of adding vinegar in order to increase the shelf-life of cabeça de xara, by reducing the contaminating microbiota responsible for spoilage, as well as controlling the pathogen Listeria monocytogenes. Three independent batches were produced and proximate composition, pH, aw, microbiological parameters and biogenic amines content evaluated. A sensory analysis was also performed throughout the storage period. No significant differences between control and vinegar samples was found regarding the proximate composition of cabeça de xara. As expected, pH is lower in the vinegar samples, however no differences in aw were observed between the two treatments. L. monocytogenes was present from the first month on only in one batch in the control treatment. However, it is inhibited by the addition of vinegar until the third month of storage, where L. monocytogenes is present but below the limit established in the 2073/2005 regulation. The presence of vinegar significantly decreased the content in biogenic amines, particularly cadaverine, putrescine and tyramine, throughout the storage period. Concerning sensory evaluation, no vinegar taste was reported by the panellists in a depreciating way

USE OF STARTER CULTURES TO IMPROVE PORTUGUESE TRADITIONAL SAUSAGES

In Mediterranean countries, such as Portugal, traditional dry-fermented sausages are highly appreciated. They are often still being manufactured in small processing units, according to traditional procedures. The aims of the present study were to evaluate the effect of different starter cultures and their optimal concentration, to reduce the microbial load in end-products, with the purpose to improve the sausages’ safety, without deteriorating sensory acceptability. pH, aw, colour, texture and microbiological profile were assessed. On the other hand, a sensory panel evaluated the products. Based on the first results, S. xylosus and L. sakei were chosen to be inoculated together with a yeast strain. In the mixed starter culture experiment, a food safety issue arose probably related to the higher aw value (0.91). The presence of Salmonella spp. detected in a few end-products sausages did not allow a full sensory evaluation in the mixed starter culture experiment. However, in the two preliminary experiments, the use of starter cultures did not depreciate the panellists’ overall appreciation and products acceptability

Autochthonous starter cultures are able to reduce biogenic amines in a traditional portuguese smoked fermented sausage

Traditional smoked fermented sausages are highly appreciated in Portugal and are mostly manufactured according to traditional procedures. The aim of the present work was to evaluate the effect of autochthonous starter cultures on the safety and quality of a smoked fermented sausage, Painho da Beira Baixa (PBB), preserving its sensory quality. Physicochemical parameters, namely pH and water activity (aW), microbiological parameters, biogenic amines, colour, texture profile and sensory attributes were assessed. Different starters were selected based on our previous work. Staphylococcus equorum S2M7, Staphylococcus xylosus CECT7057, Lactobacillus sakei CV3C2, Lactobacillus sakei CECT7056 and a yeast strain (2RB4) were co-inoculated in meat batters at defined concentrations. Starters had a significant effect on the reduction of pH. Enterobacteria and Listeria monocytogenes were not detected in inoculated end-product sausages. Moreover, sausages inoculated with S. equorum S2M7/L. sakei CV3C2/yeast 2RB4 showed a significant reduction in the total content of biogenic amines. No significant differences between treatments were observed for colour and texture parameters, except for adhesiveness. The studied starters did not compromise the sensory characteristics of PBB. To our knowledge, this is the first comprehensive study on the quality and safety of this type of smoked fermented sausage from the central region of Portugalinfo:eu-repo/semantics/publishedVersio

Qualidade e segurança de Paios com baixo teor em sal provenientes de raças autóctones

As raças suínas autóctones Alentejano (Al) e Bísaro (Bi) foram tradicionalmente criadas em sistemas extensivos, coexistindo na mesma região e dando origem ao porco “Ribatejano”, resultante do cruzamento entre Al e Bi. No âmbito do projeto europeu TREASURE foram produzidos, numa unidade local, paios com baixo teor em sal (2% NaCl) usando os quatro genótipos: Al, Bi e os híbridos BiAl e AlBi. O principal objetivo do presente trabalho era avaliar as diferenças entre genótipos nos paios com baixo teor em sal. A qualidade e segurança dos paios foi avaliada através de parâmetros físico-químicos e microbiológicos. Encontraram-se diferenças significativas no teor de gordura, com valores significativamente mais elevados nos paios de Bi, que também tinham pH mais elevado e menores valores de aW. O conteúdo total de aminas biogénicas foi maior nos paios de AlBi e Al, principalmente pelos conteúdos superiores de putrescina e cadaverina

Co-inoculation with Staphylococcus equorum and Lactobacillus sakei reduces vasoactive biogenic amines in traditional dry-cured sausages

Dry-cured sausages are traditional in Mediterranean countries, and Paio do Alentejo (PA) is one of the most popular in South Portugal. The aim of the present work was to evaluate the effect of combined starters on the safety and quality of PA preserving its sensory quality. Physicochemical parameters, namely pH and water activity (aW), microbiological parameters, biogenic amines, color, texture, and sensory attributes were assessed. Three starter cultures were used, namely Staphylococcus equorum S2M7 and Lactobacillus sakei CV3C2, both separate and combined with the 2RB4 yeast strain at a concentration of 106 cfu/g. Dextrose 0.25% was added to the meat batter. Starters had a significant effect on the reduction of aW values (0.845 to 0.823). The treatment with L. sakei as well as the co-inoculation of L. sakei with S. equorum effectively reduced the L. monocytogenes counts to undetectable levels. Sausages co-inoculated with S. equorum S2M7/L. sakei CV3C2 showed a significant reduction in the content of vasoactive amines, namely tryptamine (26.21 to 15.70) and -phenylethylamine (4.80 to 3.69). Regarding texture, control PA showed higher hardness values, and the starters promoted the cohesiveness of the batter while reducing chewiness. The studied starters did not compromise the sensory characteristics of PAinfo:eu-repo/semantics/publishedVersio

Effect of autochthonous starter cultures in the production of "Paio", a traditional Portuguese dry- cured sausage

Traditional dry-cured sausages are highly appreciated in Mediterranean countries. The aim of the present study was to evaluate the effect of different starter cultures in the sausages Alentejano pig meat was used to prepare drycured sausages in a local factory. Staphylococcus xylosus, Lactobacillus sakei and a yeast strain were inoculated at a concentration of 106 cfu/g meat batter both in separate and in mixed culture. Three independent batches with two replicates per treatment were produced. Samples were collected throughout the ripening process. pH and aw were determined according to the ISO standards. Microbiological counts of total mesophiles, total psycrotrophs, anaerobes, coagulase-negative staphylococci (CNS), lactic acid bacteria (LAB), enterobacteria, yeasts and moulds and Listeria monocytogenes were done according to the respective ISO standards, as well as detection of Salmonella spp. Biogenic amines quantification was performed by HPLC as described by Roseiro et al. (1). The treatment with L. sakei alone was the most effective in reducing the contamination level both with Salmonella spp. and L. monocytogenes, however this effect seems to be lost in the mixed cultures. The presence of the yeast strain seems to increase the levels of phenylethylamine and histamine. The contents in cadaverine, putrescine and tyramine were generally lower in the inoculated sausages. Regarding tyramine, the treatments with L. sakei showed significantly lower values. No significant differences between treatments were observed for both spermine and spermidine

EFFECT OF GENOTYPE AND SALT CONCENTRATION ON THE QUALITY OF PORTUGUESE TRADITIONAL PAIOS

Nowadays, there is an increasing demand for traditional food products, which is concomitant with higher nutritional and health concerns. The need to reduce salt concentrations or replace NaCl by salt substitutes, such as KCl, has been evidenced by the World Health Organisation, who recommends daily salt intake values of 5 g, corresponding to less than 2 g of sodium. Alentejano (Al) and Bísaro (Bi) are two autochthonous Portuguese pig breeds, traditionally reared in extensive systems. Al is a fatty pig closely related to the Iberian pig, belonging to the group of the Mediterranean pigs, while Bi fits within the Celtic pigs. One of the most appreciated Portuguese traditional drycured meat products is Paio. For this study made in the frame of the European TREASURE* project, Paios were manufactured at a local production unit, using two different pig genotypes: pure breed Al and the hybrid genotype BiAl. Products were made with two different NaCl concentrations in the final product, namely 2 and 6%. The main aim of this work was to evaluate the differences in quality between the two genotypes, while attempting to reduce salt without compromising safety standards or consumer acceptability. The effect of genotype and salt content on physicochemical and microbiological parameters, along with sensory attributes, was studied on Portuguese Paios. Regarding total lipid content, there were significant differences between genotypes, with hybrid BiAl products showing higher values. Concerning pH and water activity (aw), significant differences were observed between salt contents, with low-salt products showing lower pH, but higher aw values. The total content in biogenic amines was higher in Al products, mainly due to the amounts of putrescine and cadaverine, resultant from the presence of decarboxylating bacteria. Generally, lowsalt Paios showed a higher content in biogenic amines. Furthermore, salt reduction did not depreciate the quality and acceptability of sausages

EFFECT OF GENOTYPE AND SALT CONCENTRATION ON THE QUALITY OF PORTUGUESE TRADITIONAL PAIOS

Nowadays, there is an increasing demand for traditional food products, which is concomitant with higher nutritional and health concerns. The need to reduce salt concentrations or replace NaCl by salt substitutes, such as KCl, has been evidenced by the World Health Organisation, who recommends daily salt intake values of 5 g, corresponding to less than 2 g of sodium. Alentejano (Al) and Bísaro (Bi) are two autochthonous Portuguese pig breeds, traditionally reared in extensive systems. Al is a fatty pig closely related to the Iberian pig, belonging to the group of the Mediterranean pigs, while Bi fits within the Celtic pigs. One of the most appreciated Portuguese traditional drycured meat products is Paio. For this study made in the frame of the European TREASURE* project, Paios were manufactured at a local production unit, using two different pig genotypes: pure breed Al and the hybrid genotype BiAl. Products were made with two different NaCl concentrations in the final product, namely 2 and 6%. The main aim of this work was to evaluate the differences in quality between the two genotypes, while attempting to reduce salt without compromising safety standards or consumer acceptability. The effect of genotype and salt content on physicochemical and microbiological parameters, along with sensory attributes, was studied on Portuguese Paios. Regarding total lipid content, there were significant differences between genotypes, with hybrid BiAl products showing higher values. Concerning pH and water activity (aw), significant differences were observed between salt contents, with low-salt products showing lower pH, but higher aw values. The total content in biogenic amines was higher in Al products, mainly due to the amounts of putrescine and cadaverine, resultant from the presence of decarboxylating bacteria. Generally, lowsalt Paios showed a higher content in biogenic amines. Furthermore, salt reduction did not depreciate the quality and acceptability of sausages