Postharvest storage of lychee (Litchi chinensis Sonn.)

Author(s)

Juan Saavedra del Aguila

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2009-02-11

Examining board members

Ricardo Alfredo Kluge; Benedito Carlos Benedetti; Marcos José de Oliveira Fonseca; Angelo Pedro Jacomino; João Alexio Scarpare Filho

• Advisor: Ricardo Alfredo Kluge

Abstract

The purpose of the present work was carried out with the objective to determine and to evaluate the physicochemical, physiological, biochemical and sensorial answers associated to the techniques of postharvest lychee conservation, and for that six experiments were evaluated. In the first experiment, the effect of the storage temperature (0, 5, 10, 15 and 20ºC) was evaluated in lychees \'Bengal\' for 15 days. The respiratory rate and ethylene production were influenced significantly by the storage temperature, and the increase of the storage temperature caused more losses of soluble solids (ºBrix), ascorbic acid and appearance. Temperatures of 0 and 5ºC are recommended for lychee conservation for 15 days, in the conditions of the present experiment. In a second experiment, packages of polyvinyl chloride (PVC) films (12, 14 and 17 m thickness) were evaluated; low density polyethylene (LDPE) films of 10 and 20 m; polypropylene (PP) plastics films of 0,06 and 10 m; and polyethylene terephthalate (PET) packages, in lychee \'Bengal\' stored at 5ºC and 90% RH during 15 days. The films PP 0,06 and 10 µm, as well as the films PEBD 10 and 20 µm, presented drastic reductions of the tenors of O2 and significant increases of CO2. For the conditions of this work it was concluded that the polyvinyl chloride (PVC) films of 12, 14 and 17 µm and the packing of polyethylene terephthalate (PET) are the best films or packages for the lychee \'Bengal\' storage at 5ºC for 15 days. The third experiment studied the effect of the application of different antioxidants in the conservation of lychees \'Bengal\' stored at 5ºC and 90% HR during 15 days. It was verified that the treatment with citric acid reduces the respiratory rate of lychee during the storage at 5ºC. However, none of the tested antioxidants was efficient to minimize the pericarp browning of the lychees during the cold stored. The fourth experiment evaluated the effect of the application of different concentrations of chloride of calcium (CaCl2) on lychees \'Bengal\' stored at 5ºC and 90% HR during 15 days. It was concluded that the chloride of calcium reduces the respiratory rate of lychees stored at 5ºC, but it is not efficient to minimize the red coloration pericarp loss of these fruits during the cold stored. In the fifth experiment it was studied the effect of the application of different coatings in the lychees \'Bengal\' quality stored at 5ºC and 90% HR during 15 days. It was concluded that none of the coatings or waxes tested minimized the of lychess quality loss stored at 5ºC during 15 days. The sixth experiment evaluated different times and temperatures of hydrocooling in lychees \'B3\' for 10 days. In the conditions of this experiment, it was concluded that the hydrocooling of the lychee aids in the minimization of the loss of fruit quality, but it favors the appearance of high indexes of rottenness. (AU)