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- Shelf life of minimally processed apple (cv. Jonagored) determined by colour changesPublication . Rocha, A. M. C. N.; Morais, A. M. M. B.Physical, chemical and sensory changes of cut apple (cv. Jonagored) stored in the dark at 4 °C were evaluated. Colour was found to be the critical parameter for this product. Apple cubes underwent severe surface browning primarily during the initial days of storage. The shelf-life of cut apple was therefore very limited, to three days maximum. Sensory analyses and objective quality evaluations of cut apple were considered highly correlated in terms of colour and flavour, especially with respect to fructose and sucrose, showing that the selected sensory attributes were good indicators of overall fruit quality.
- Physico-chemical qualities of minimally processed carrot stored under vacuumPublication . Rocha, Ada M. C. N.; Mota, Catarina C. A. R.; Morais, Alcina M. M. B.In the last decades, consumers have become more health conscious in their food choices, but they have also less time to prepare healthy meals. Increased consumer interest in fruits and vegetables as healthy foods in association with a modification of lifestyles has accelerated and increased efforts to find potential alternatives to the traditional consumption of fresh fruit and vegetables. This situation opens the possibility for new categories of products that are intended to be presented to foodservice operators conveniently peeled, cored or sliced in prepared packages, with fresh-like quality; they are called minimally processed (MP). The use of vacuum packaging presents a potential alternative to achieve an inhibition of the progress of deterioration of foodstuffs. In this study, the physical qualities of MP carrots (cv. Nantes) stored under refrigeration and in vacuum packaging were evaluated. The beneficial effect of vacuum packaging was noticeable only in the colour, sugar content and phenolic compounds of carrots.
- Modified atmosphere package for apple ‘Bravo de Esmolfe’Publication . Rocha, A.M.C.N.; Barreiro, M.G.; Morais, Alcina M. M. B.Apple Bravo de Esmolfe original from the parish of Esmolfe is cultivated in specific regions of Portugal. This cultivar of medium to low production requires very low temperatures, but it is extremely sensitive to frost. The aim of this work was to evaluate the influence of modified atmosphere on the quality of apple (cv. Bravo de Esmolfe) during cold storage. Apples packed in modified atmosphere lost less weight, presented better colour, and preserved better firmness than fruits stored in air.
- Effect of vacuum packaging in nutritional quality of minimally processed potatoPublication . Rocha, Ada M. C. N.; Morais, Alcina M. M. B.; Coulon, Emilie C.
- Qualidade de puré de kiwi armazenado sob vácuoPublication . Drieghe, Koen; Rocha, Ada M. C. N.; Morais, Alcina M. M. B.
- Polyphenoloxidase activity of minimally processed "Jonagored" apples (Malus domestica)Publication . Rocha, A. M. C. N.; Morais, Alcina M. M. B.The influence of three chemical dips using ascorbic acid (AA), citric acid (CA) and calcium chloride (CC) on the polyphenoloxidase (PPO) activity and on the total phenolic content of minimally processed (MP) apple (Malus domestica, cv. Jonagored) during cold storage was evaluated and a potential relationship with enzymatic browning was investigated. An ascorbic acid dip (42.6 mM) of 5 min duration was the most efficient chemical treatment in reducing the PPO activity of apple cubes. A 92% inhibition was achieved after 7 days of storage at 4C. All treatments were advantageous in comparison to the control in reducing color changes. Color changes, determined by absorbance at 420 nm (soluble pigments) and lightness (L) (insoluble pigments) of apple cubes treated with ascorbic acid were correlated with total phenolic content. No correlation was observed between PPO activity and tristimulus color parameters, browning index or total phenolic content of AA-treated apple cubes.
- Influence of chemical treatment on polyphenoloxidase activity while related to colour changes of minimally processed ‘Jonagored’ applePublication . Rocha, Ada M. C. N.; Morais, Alcina M. M. B.
- Qualidade de puré de kiwi armazenado sob vácuoPublication . Koen, Drieche; Rocha, Ada M.C.N.; Morais, Alcina M. M. B.
- Effects of minimal processing and temperature on respiration rate of carrot (cv. Nantes)Publication . Rocha, Ada M. C. N.; Mota, Catarina; Morais, Alcina M. M. B.
- Influence of controlled atmosphere storage on polyphenoloxidase activity in relation to colour changes of minimally processed ‘Jonagored’ applePublication . Rocha, A. M. C. N.; Morais, M. M. B.The effects of the storage atmosphere composition (2% O2 + 4% CO2; 2% O2 + 8% CO2; 2% O2 + 12% CO2) on polyphenoloxidase activity and phenolic content of the ‘Jonagored’ apple variety during cold storage was evaluated, and the relationship with enzymatic browning investigated. Controlled atmosphere storage inhibited the polyphenoloxidase (PPO) activity of apple cubes during storage. It seems that the higher the concentration of carbon dioxide in the storage atmosphere the higher inhibition of PPO and the lower browning achieved. At the substrate-enzyme levels investigated, the phenolic content, substrate level was the major factor determining darkening.
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