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- Microstructural, physicochemical and sensorial effects of pears (cv. Rocha) stored under controlled atmosphere conditionsPublication . Galvis-Sánchez, Andrea C.; Teixeira, Claudia; Fonseca, Susana C.; Malcata, F. Xavier
- Effect of different levels of CO2 on the antioxidant content and the polyphenol oxidase activity of ‘Rocha’ pears during cold storagePublication . Galvis-Sánchez, Andrea C.; Fonseca, Susana C.; Gil-Izquierdo, Ángel; Gil, María I.; Malcata, F. XavierAbstract: Pears (Pyrus communis L. cv. ‘Rocha’) were exposed to air or controlled atmosphere (CA) containing various concentrations of CO2: 0, 0.5 and 5 kPa, all with 2 kPa O2. After 4months of storage at 2 ◦C, the fruits were transferred to air at room temperature, and assessed in terms of soluble solids, titratable acidity, pH, incidence of brown heart and flesh browning, phenolic content, vitamin C content and polyphenol oxidase activity. By 4months of storage, soluble solids and pH increased, and acidity decreased relative to harvest, but no differences were detected between pears stored under air or any of the CA tested. Higher contents of hydroxycinnamic derivatives and flavan-3-ols in the peel than in the flesh were recorded. However, the content of arbutin was higher in the flesh than in the peel, whereas flavonols were only detected in the peel. In general, hydroxycinnamic derivatives and flavonols were stable throughout storage, but flavan-3-ols decreased in concentration under air or CA. Arbutin was the only phenolic compound that increased in concentration as time elapsed. No clear relation was found between the storage conditions tested and the phenolic concentration in pears. Regarding ascorbic acid (AA) and dehydroascorbic acid (DHA), their concentrations were higher in the peel than in the flesh. Furthermore, AA and DHA were strongly affected by storage: the former decreased, whereas the latter increased in content. A decrease in PPO activity was apparent after harvest and during storage, particularly under higher levels of CO2. The combination 2 kPa O2 + 5kPa CO2 increased the incidence of internal disorders (viz. brown heart and flesh browning) after storage.
- Relationship between instrumental and sensory quality parameters of various pear varietiesPublication . Galvis-Sánchez, Andrea C.; Teixeira, Claudia; Fonseca, Susana C.; Malcata, F. Xavier
- Effect of CA-storage on the physical and sensorial quality of "Rocha" pearPublication . Galvis-Sanchez, Andrea C.; Fonseca, Susana C.; Morais, Alcina M. M. B.; Malcata, F. Xavier
- Physicochemical and Sensory Evaluation of ‘Rocha’ Pear Following Controlled Atmosphere StoragePublication . Galvis-Sánchez, A. C.; Fonseca, S. C.; Morais, A. M. M. B.; Malcata, F. XavierThe effects of several processing factors (storage time, time in the open air at room temperature, and overhead concentrations of O2 and CO2) on color, firmness, polyphenol oxidase (PPO) activity, and sensory attributes of pears (cv. Rocha) grown in 2 locations were studied using a multiple linear regression model. Backward elimination (F ≥ 0.005) was used to assess the significant factors. Extended storage time, long-time exposure at room temperature, and high O2 concentration played major roles on color changes assessed instrumentally and further confirmed by a sensory panel. Firmness was strongly affected by storage time and by time in the open air at room temperature. Finally, PPO activity was dependent on the growing location.
- Effects of preharvest, harvest and postharvest factors on the quality of pear (cv. "Rocha") stored under controlled atmosphere conditionsPublication . Galvis-Sánchez, Andrea C.; Fonseca, Susana C.; Morais, Alcina M. M. B.; Malcata, F. XavierPears (cv. Rocha’) grown at two locations and picked up at various times during the harvest season were assessed for firmness and colour, following 9 mo of storage under air or under controlled atmosphere conditions. A second-order polynomial was able to accurately fit the effect of time of harvest on pear’s quality, in an essentially empirical modelling effort; the best estimates of the parameters therein depend on the growing location, as well as on the atmosphere gas composition prevailing during storage.
- Sensorial and physicochemical quality responses of pears (cv Rocha) to long-term storage under controlled atmospheresPublication . Galvis-Sánchez, Andrea C.; Fonseca, Susana C.; Morais, Alcina M. M. B.; Malcata, F. XavierPears (cv Rocha) kept under controlled atmospheres (CA) and air were evaluated after longterm storage in terms of sensory attributes and physicochemical parameters, namely colour, firmness, polyphenoloxidase (PPO) activity and concentration of hydroxycinnamic compounds. The CA conditions were all combinations of 2 and 4% (v/v) O2 with 0.5 and 1.5% (v/v) CO2. Storage under CA conditions produced a beneficial effect on ‘Rocha’ pears in maintaining their quality and, consequently, in extending their shelf life and acceptability. Clear differences in sensorial attributes, colour parameters and PPO activity were found between CA- and air-stored pears. The effect provided by the CA conditions persisted throughout the time of exposure to the open air. The 2%O2 concentration produced amore beneficial effect than its 4%counterpart on the sensorial and physical characteristics of the pears.The former concentration of O2 prevented yellowing and allowed regular softening, hence keeping a high flavour quality. No clear effects could be associated with CO2 levels. Empirical models were developed that describe the effects of O2 and CO2 concentrations, as well as time at room temperature on physicochemical parameters pertaining to ‘Rocha’ pears.