Browsing by Author "Almeida, D. P. F."
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- Physicochemical quality, macronutrients, and dietary fiber in apples from the protected geographical indication ‘Maçã de Alcobaça’, PortugalPublication . Almeida, D. P. F.; Gomes, M. H.Apple is a major fruit in the European diet. The range of cultivar types and origins diversify the nutritional composition of apples. Eight apple cultivars (Malus xdomestica Borkh. 'Casa Nova', 'Fuji', 'Galaxy', 'Golden Delicious', 'Granny Smith', 'Jonagored', 'Reinette', and 'Starking') with the " Maca de Alcobaca" Protected Geographical Indication (PGI), Portugal, were harvested at commercial maturity, stored for 3 to 3.5 months at 0 degrees C, and characterized at the edible stage for their nutritional composition. Fruit quality was assessed by color, soluble solids content, titratable acidity, pH, Thiault index and firmness. The concentration moisture, dry matter, carbohydrates, protein, fat, ash, and fiber defined the nutritional profile. 'Reinette' had highest soluble solids content, titratable acidity, carbohydrates, protein, ash, energy, dry matter. 'Granny Smith' had the lowest soluble solids and carbohydrates contents, dry matter and energy. 'Casa Nova', a traditional cultivar, had high fiber content. Energy content varied by more than 30%, lowest in 'Granny Smith' and highest in 'Reinette', and is strongly correlated with dry matter and soluble solids content. The cultivarspecific range of nutritional value provides a basis for market segmentation based on nutritional content.
- Volatile profile of fresh-cut ‘Rocha’ pear under various temperatures and oxygen levelsPublication . Gomes, M. H.; Beaudry, R. M.; Almeida, D. P. F.The objective of this work was to evaluate the effect of temperature and oxygen concentration on the volatile profile of packed fresh-cut 'Rocha' pear, to integrate flavor changes in the development of preservation technologies for fresh-cut fruit. Slices of 'Rocha' pear were packed in low-density polyethylene pouches, with varying fruit weight, film surface area and film thickness, and were stored at 0, 5, 10 and 15°C. After 5 days at 15°C, 8 days at 10°C and 10 days at 5 and 0°C, steady-state O2 and CO2 partial pressures were achieved and the volatile composition inside packages was measured. Samples were grouped in four classes depending on the levels of oxygen: high (>8 kPa), intermediary (8-1 kPa), low (1-0.5 kPa), and very low (<0.5 kPa, anaerobic metabolism). The acetate esters (methyl-, ethyl-, propyl-, butyl-, 2-methylbutyl-, pentyl- and hexyl-acetate) and alcohols (ethanol, butanol, 2-methyl butanol and hexanol) were analyzed for each atmosphere group. Volatile relative abundance was significantly affected by temperature and oxygen level. The levels of ethanol, the main alcohol detected, increased with temperature and oxygen depletion. Acetate esters represented 20 to 25% of the total volatiles, with butyl acetate accounting for almost 50% of the total acetate esters. Absolute levels of total acetate esters were significantly lower at 0°C than at higher temperatures, but 2-methylbutyl-, pentyl- and hexyl-acetate were significantly higher at this temperature. Decreasing oxygen levels to anaerobiose increased the total acetate esters, due to an increase in ethyl acetate, while other esters decreased. 2-Methylbutyl acetate, a flavor-important volatile in pear described as “fruity, banana, candy, citrus, peanut”, and hexyl acetate were more abundant at 0°C and oxygen levels above 8 kPa. These results suggest that the oxygen levels affect volatiles of fresh-cut pear; the design of modified atmosphere packaging should take this effect into consideration for shelf life termination.