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- The effect of seasoning with herbs on the nutritional, safety and sensory properties of reduced-sodium fermented Cobrançosa cv. table olivesPublication . Pires-Cabral, Paula; Barros, Tânia; Mateus, Tânia; Prata, Jessica; Quintas, CéliaThis study aimed at evaluating the effectiveness of seasoning Cobrancosa table olives in a brine with aromatic ingredients, in order to mask the bitter taste given by KCl when added to reduced-sodium fermentation brines. Olives were fermented in two different salt combinations: Brine A, containing 8% NaCl and, Brine B, a reduced-sodium brine, containing 4% NaCl + 4% KCl. After the fermentation the olives were immersed in seasoning brines with NaCl (2%) and the aromatic herbs (thyme, oregano and calamintha), garlic and lemon. At the end of the fermentation and two weeks after seasoning, the physicochemical, nutritional, organoleptic, and microbiological parameters, were determined. The olives fermented in the reduced-sodium brines had half the sodium concentration, higher potassium and calcium content, a lower caloric level, but were considered, by a sensorial panel, more bitter than olives fermented in NaCl brine. Seasoned table olives, previously fermented in Brine A and Brine B, had no significant differences in the amounts of protein (1.23% or 1.11%), carbohydrates (1.0% or 0.66%), fat (20.0% or 20.5%) and dietary fiber (3.4% or 3.6%). Regarding mineral contents, the sodium-reduced fermented olives, presented one third of sodium, seven times more potassium and three times more calcium than the traditional olives fermented in 8% NaCl. Additionally, according to the panelists' evaluation, seasoning the olives fermented in 4% NaCl + 4% KCl, resulted in a decrease in bitterness and an improvement in the overall evaluation and flavor. Escherichia coli and Salmonella were not found in the olives produced.
- Production of split table olives of the Cobrancosa cultivar: a kinetic study of the fermentation profilePublication . PRATA, JESSICA; Barros, Tânia; Mateus, Tânia; Quintas, Célia; Pires-Cabral, PaulaThe aim of this study was to evaluate the effect of the Cobrancosa cultivar olive ripeness on the physicochemical parameters and model their progression profile throughout the fermentation period. Green and turning color olives undertook fermentation due to fruit and environmental microbiota resulting in final brines with the required acidity values and absence of coliforms, Escherichia coli, Salmonella and Listeria monocytogenes. The Monod model was used to explain the changes of a(W), total acidity and total phenolic content in the brines, and the same kinetic with inhibition was fitted to the changes of reducing sugar concentration in the brines. The inverse power model was adjusted to salt content in brines, a(W), total acidity, reducing sugars and total phenolic content in the olives. The Naperian logarithmic function was fitted to the changes of the surface color parameter (-a/b) of the fruits. For both olives, the models adjusted to the experimental data were the same, showing a similar trend in the physicochemical profiles, probably due to the previously fruit splitting, which promotes nutrients diffusing into the brines and the influx of salt into the olives during fermentation. However, different model parameters were estimated, depending on the ripeness degree, namely for total acidity, reducing sugars and total phenolic content of the brines, showing lower nutrients diffusion rates from the unripe olive pulp, through the skin into the brine, due to the hardness of the cell wall structures in this maturation stage.
- Incorporation of capric acid in pumpkin seed oil by sn-1,3 regioselective lipase-catalyzed acidolysisPublication . Sousa, Vanessa; Campos, Vitor; Nunes, Patricia; Pires-Cabral, PaulaStructured lipids (SLs) are novel triacylglycerols obtained by changing the native fatty acid (FA) profiles or by the incorporation of a new desired FA in the acylglycerol backbone. These modified fats present important medical and functional properties for food applications. This work aimed to synthetize a MLM-type SL, which consists of triacylglycerols containing a medium-chain FA (M) at sn-1,3 positions and a long-chain FA (L) at sn-2 position, by acidolysis of pumpkin seed oil with capric acid, catalyzed by a commercial lipase preparation from Thermomyces lanuginosa (Lipozyme TL IM). Reactions were performed at 45 degrees C, in solvent-free media, at 1: 2 molar ratio (pumpkin seed oil: capric acid) and a fixed amount of immobilized lipase of 5%, 10%, 15% or 20%. Incorporations of C10: 0 increased with time up to 31 h (29.9 +/- 0.7 mol-%) when 5% lipase load was used. Significant differences were only observed between the results obtained with 5 and 20% of biocatalyst load. The subsequent experiment was carried out with 5% lipase load, at 45 degrees C, 1: 2 molar ratio and in the presence of n-hexane. The results showed slightly higher incorporation yields in the presence of solvent, namely at 48 h-reaction (34.7 +/- 1.0 mol-%). However, since the structured lipids are to be used in food products, together with environmental and economic concerns, solvent-free systems are preferred. In this study, the synthesis of a MLM-type SL from pumpkin seed oil for food uses was well succeeded.
- Effect of chloride salts on the sensory and nutritional properties of cracked table olives of the Macanilha Algarvia cultivarPublication . Saúde, Cíntia; Barros, Tânia; Mateus, Tania; Quintas, Célia; Pires-Cabral, PaulaThe effect of sodium chloride replacement with potassium chloride and/or calcium chloride in the fermentation brines on the physicochemical, organoleptic and nutritional profiles of cracked table olives was studied using no more than 8% salt. Although all brines led to vigorous fermentation with the desired characteristics of acidity and saltiness, the sensory panel rated the olives fermented in 8%NaCl and 4%NaCl + 4%KCl as the best, in terms of flavor and overall attributes. The olives fermented in the other brines (4%NaCl + 4%CaCl2, 4%KCl + 4%CaCl2 and 2.7%NaCl + 2.7%KCl + 2.7%CaCl2) were not acceptable. Olives fermented in 4%NaCl + 4%KCl had lower fat, carbohydrates, dietary fiber, calories and similar amounts of phenolic compounds and Ca as the 8%NaCl treatment. In addition, the former had increased K (672%) and reduced Na (19%), making them more nutritionally acceptable. This alteration might be beneficial and allow the olive market to reach new customers or present current customers with a potentially healthier product.