Redução do escurecimento do pericarpo de lichia com ácido clorídrico

Abstract

RESUMO -Foram avaliados os efeitos da imersão em soluções com diferentes concentrações de ácido clorídrico (HCl) sobre a redução do escurecimento do pericarpo e a conservação pós-colheita de lichia. Lichias 'Bengal' foram colhidas com o pericarpo completamente vermelho e imersas por dois minutos em 0 (controle); 0,25; 0,5; 1,0 e 2,0 M de HCl. Após os tratamentos, os frutos foram acondicionados em bandejas de poliestireno expandido e recobertos com filme de policloreto de vinila (PVC). Os frutos foram armazenados em câmara fria a 10,0 ± 0,9°C e 90 ± 5% de UR e avaliados de 4 em 4 dias. Após 24 dias de armazenamento, os frutos de todos os tratamentos apresentaram perda de massa fresca em torno de 4,5%. Até o 16 o dia de armazenamento, os frutos tratados com HCl 2,0 M não apresentaram alteração significativa na coloração do pericarpo (ΔE, h e L*) em relação ao dia da colheita. Visualmente, esses frutos permaneceram sem alterações perceptíveis na coloração, até os 24 dias de armazenamento refrigerado. Naqueles não tratados (controle) e nos tratados com HCl a 0,25M e 0,5 M, o escurecimento do pericarpo iniciou-se no 4 o dia de armazenamento refrigerado. Termos para indexação: Litchi chinensis Sonn., cor da casca, armazenamento refrigerado. REDUCTION OF THE PERICARP BROWNING OF LYCHEE WITH HYDROCHLORIC ACIDABSTRACT -This study assessed the effects of immersion in different concentrations of hydrochloric acid (HCl) on pericarp color retention and postharvest conservation of lychees. 'Bengal' lychees were harvested with completely red pericarp and immersed for two minutes in HCl at concentrations of 0 (control), 0.25, 0.5, 1 and 2 M. After the treatments, fruits were packed in expanded polystyrene trays and covered with polyvinyl chloride film (PVC). The fruits were stored in cold chamber at 10 ± 0.9°C and 90 ± 5% RH. The fruits were evaluated every 4 days over a period of 24 days. After 24 days of storage, fruits of all treatments showed weight loss of around 4.5%. By the 16 th day of storage, fruits treated with 2 M HCl showed nonsignificant changes in pericarp color (ΔE, Hue angle and luminosity) in relation to the harvest day. These fruits remained without visually perceptible change in color up to 24 days of cold storage. Pericarp darkening began on the 4 th day of cold storage in fruits untreated (control) and treated with 0.25 and 0.5 M of HCl.

Uso de embalagem e da refrigeração no armazenamento de lichias “Bengal”

“…The titratable acidity levels decreased significantly during storage (Table 4). These results were also observed by Kumar et al (2012), for fruits of the cultivars "Shahi" and "China" treated with sodium hypochlorite, ascorbic acid, potassium metabisulfite, hydrochloric acid and gamma irradiation, and by Salomão et al (2012), for the cultivar "Bengal", in treatments with fruits immersed in different concentrations of hydrochloric acid and packaging in polystyrene trays covered with PVC. The significant increase observed in the values of the SS/TA ratio (Table 4) was also found by Hojo et al (2011), and reflected the maintenance of the soluble solids content and the decrease in the titratable acidity levels.…”