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- Physical and chemical quality characteristics of strawberries after storage are reduced by a short delay to coolingPublication . Nunes, M. C. N.; Brecht, J. K.; Morais, A. M. M. B.; Sargent, S. A.Chandler’, ‘Oso Grande’ and ‘Sweet Charlie’ strawberries were forced-air precooled after delays of 0 or 6 h at 30 °C to study the effect of delaying precooling on physical and chemical quality characteristics of strawberry fruit. Fruit pulp temperatures were equilibrated to 30 °C prior to the start of each experiment to minimise water loss differences between treatments. Evaluations were made after storage for one week at 1 °C plus one day at 20 °C. Delaying the start of precooling resulted in about 50% greater water loss than in control fruit, which was evident as increases in superficial shrivelling. Tissue firmness values were also 14–22% lower in fruit from the delayed treatment. Fruits were darker (lower L* value), less bright (lower chroma) and apparently less red (lower a* value) with the cooling delay, although hue angle was also lower, which may reflect the occurrence of browning. No significant differences in pH were observed in these experiments, but titratable acidity was slightly lower with the delay to cooling. Delaying precooling also caused increased losses of ascorbic acid, soluble solids, fructose, glucose and sucrose compared to controls. In spite of differences related to harvest time and the variability among cultivars, the general responses were quite similar and illustrate the importance of rapid precooling and subsequent storage at low temperature for maintenance of acceptable appearance, texture and nutritive value of strawberries.
- Influence of delayed CA storage on ascorbic acid content and brown-heart incidence in 'Rocha' pearPublication . Morais, A. M. M. B.; Avelar, M. L.; Rodrigues, A. C.
- Controlling Temperature and Water Loss to Maintain Ascorbic Acid Levels in Strawberries During Postharvest HandlingPublication . Nunes, M. C. N.; Brecht, J. K.; Morais, A. M. M. B.; Sargent, S. A.Chandler’, ‘Oso Grande’ and ‘Sweet Charlie’ strawberries were stored for 8 days at 1 or 10°C, or 4 days at 20°C, either unwrapped or wrapped in PVC film to retard were conducted during the 1 water loss. Total ascorbic acid (AA) content was expressed on a dry weight basis to correct for water loss differences between treatments. Loss of AA was low and did not differ between wrapped treatments at 1 and 10°C, but was much greater at 20°C. Wrapping reduced AA loss by 5-fold at 1 and 10°C and by 2-fold at 20°C. The effect was not due to modification of O2 and CO2 levels in wrapped treatments, which was minimal. The results indicate that water loss had a greater effect on AA levels than temperature. Combining wrapping with storage at 1 or 10°C reduced AA loss by 7.5-fold compared to unwrapped strawberries stored at 20°C.
- Combined effects of chemical dip and/or carrageenan coating and/or controlled atmosphere on quality of fresh-cut bananaPublication . Bico, S. L. S.; Raposo, M. F.; Morais, R. M. S. C.; Morais, A. M. M. B.The combined effect of chemical dip and/or edible coating and/or controlled atmosphere (CA) on quality of fresh-cut banana was investigated. Banana slices were subject to a 3-min dip into a solution containing 1% (w/v) calcium chloride, 0.75% (w/v) ascorbic acid and 0.75% (w/v) cysteine and/or combined with a carrageenan coating and/or combined with controlled atmosphere (3% O2 + 10% CO2). Physico-chemical and microbiological qualities were evaluated during 5 days of storage at 5 C. Dip combined with CA treatment prevented product weight loss and increase of polyphenol oxidase activity during the 5 days of storage. Colour, firmness, pH, tritatable acidity and total soluble solids values and total phenolic content presented the smallest changes. Microbial analysis showed that minimally processed bananas were within the acceptable limits during 5 days of storage at 5ºC.
- Quality of strawberries after storage is reduced by a short delay to coolingPublication . Nunes, M. C. N.; Morais, A. M. M. B.; Brecht, J. K.; Sargent, S. A.The effects of delay to cooling and storage were evaluated on postharvest quality and decay of fresh harvested strawberries. 'Chandler' strawberries were forced-air precooled after delays of 0 or 6 hours at 30°C to study the effect of delaying precooling on decay, and physical and chemical characteristics of strawberries. For decay experiments the fruits were previously inoculated with Botrytis cinerea and Rhizopus stolonifer. Fruit pulp temperature was equilibrated to 30°C prior to the start of each experiment to minimize water loss differences between treatments. Evaluations were made after storage for one week at 1°C plus one day at 20°C. Delaying the start of precooling resulted in greater water loss than in control fruits. Tissue firmness values were also lower in fruit from the delay treatment. Fruits were darker, less bright and apparently less red. No significant differences in pH were observed, but titratable acidity was slightly lower with the delay to cooling. Delaying precooling also caused increased losses of ascorbic acid, soluble solids, fructose, glucose and sucrose compared to controls, and also resulted in more decayed fruits. This illustrates the importance of rapid precooling and subsequent storage at low temperature for maintenance of an acceptable appearance, texture, flavor and nutritive value of strawberries.
- Effects of delays to cooling and wrapping on strawberry quality (cv. Sweet Charlie)Publication . Nunes, M. C. N.; Brecht, J. K.; Sargent, S. A.; Morais, A. M. M. B.'Sweet Charlie' strawberries were wrapped with PVC polymeric film, and forced-air precooled after delays of O, 6 or 8 hours at 30°C to study the effect of delaying precooling on physical and chemical quality characteristics of the strawberry. Non-wrapped fruits were used as a control. Evaluations were performed after storage for one week at 1°C plus one day at 20°C. Delaying the precooling resulted in less attractive fruits and loss of quality characteristics. Wrapped strawberries maintained better appearance and quality than nonwrapped berries.