Use of ascorbic acid in the control of browning in lychees pericarp/uso do acido ascorbico no controle do escurecimento do pericarpo de lichia

• Published in: Revista Brasileira de fruticultura Vol. 32; no. 2; p. 618
• Main Authors: Da Silva, Danieele Fabiola Pereira, Cabrini, Elaine Cristina, Alves, Robson Ribeiro, Salomao, Luiz Carlos Chamhum
• Format: Journal Article
• Language: Spanish
• Published: Sociedade Brasileira de Fruticultura 01-06-2010
• ISSN: 0100-2945

One of the biggest problems in postharvest of lychees is the pericarp browning, which has been attributed to anthocyanins degradation. The purpose of this work was to evaluate the effect of different doses of ascorbic acid to prevent pericarp browning and on the maintenance of postharvest quality of lychees. Fruits of 'Bengal' lychee with completely red pericarp were immersed in solution with different doses of ascorbic acid (0, 5, 10, 15 and 30 mM) for 5 minutes. After dried, the fruits were packed in polystyrene trays, stored in cold chamber at 5 ± 1,2°C e 90 ± 5% de RH and evaluated every other 4 days for 12 days. It was observed that the loss of fresh weight was higher in non-treated fruits with ascorbic acid. Independently of the dose, the ascorbic acid had little effect on the retention of the red color of the lychee pericarp. The polyphenoloxidase and peroxidase activities in the lychee pericarp was increased with lower doses of ascorbic acid (0, 5 and 10 mM), however, there was pericarp browning after the fourth day in all fruits treated with ascorbic acid. Ascorbic acid was not efficient in maintaining the internal quality of fruit. Index terms: Litchi chinensis Sonn., polyphenoloxidase, peroxidase, postharvest quality. Um dos maiores problemas na pos-colheita da lichia e o escurecimento do pericarpo, o qual tem sido atribuido a degradacao da antocianina. O objetivo do trabalho foi avaliar o efeito de diferentes doses de acido ascorbico na prevencao do escurecimento do pericarpo e na manutencao da qualidade pos-colheita de lichia. Frutos de lichieira 'Bengal' com o pericarpo completamente vermelho foram imersos em solucao com diferentes doses de acido ascorbico (0; 5; 10; 15 e 30 mM), por 5 minutos. Apos secagem a temperatura ambiente, foram acondicionados em bandejas de poliestireno, armazenados em camara fria a 5 ± 1,2°C e 90 ± 5% de UR e avaliados a cada 4 dias, durante 12 dias. Observou-se que a perda de massa fresca foi maior nos frutos nao tratados com acido ascorbico. Independentemente da dose, o acido ascorbico teve pouco efeito na retencao da cor vermelha do pericarpo de lichia. A atividade das enzimas polifenoloxidase e peroxidase no pericarpo foi maior com as menores doses de acido ascorbico (0; 5 e 10 mM), entretanto observou-se escurecimento a partir do quarto dia no pericarpo dos frutos tratados com este acido. O acido ascorbico tambem nao foi eficiente na manutencao da qualidade interna dos frutos. Termos para indexacao: Litchi chinensis Sonn., polifenoloxidase, peroxidase, qualidade pos-colheita.