Ethylene, Enzymatic and Respiratory Pattern Evolution in Loquat (Eriobotrya japonica (Thunb.) Lindl.) cv. Golden Nugget in the Last four Sequential Stages of Maturation

• Published in: Chilean journal of agricultural research 2011-12, Vol.71 (4), p.530-535
• Main Authors: Undurraga M, Pedro L, Olaeta C, José A, Cancino, Cristian
• Format: Article
• Language: English
• Subjects: Acids; Agricultural production; AGRICULTURE, MULTIDISCIPLINARY; AGRONOMY; Cellulase; Enzymes; Food quality; Fruits; Harvest; Proteins; Quality; Respiration; Studies
• ISSN: 0718-5839; 0718-5820; 0718-5839
• DOI: 10.4067/S0718-58392011000400005

There is some controversy regarding the respiratory pattern of loquat (Eriobotrya japonica [Thunb.] Lindl.). Thus in order to provide information on this aspect of loquat, fruit of 50-70 g, from cv. Golden Nugget were harvested in four stages of maturity: green (BBCH 709), color break (BBCH 801), yellow (BBCH 807), and orange (BBCH 809). The parameters evaluated in each stage were: soluble solids, titratable acidity, respiration, ethylene generation, and activity of the enzymes pectin methyl esterase (PME), peroxidase, polyphenoloxidase (PPO), polygalacturonase (PG), and cellulose, and the soluble solids:acidity ratio was calculated. The results show that ethylene concentration increased at the time of color break, which was not the case for the change in the respiratory rate. The activity of the peroxidase enzyme increased from the green stage to color break, while the enzymes PME, cellulase, and PG showed a constant reduction from the green to the orange stage, and PPO showed no change over the four stages studied. With regards to quality, from color break onwards soluble solids increased to 11.8 °Brix and titratable acidity dropped from 0.67 to 0.28 g L-1 malic acid. Based on these results, the conclusion is that towards the end of its development loquat cv. Golden Nugget evidence enzymatic and ethylene behavior similar to that of climacteric fruits. Evolución del patrón respiratorio, enzimático y de etileno del níspero japonés (Eriobotrya japonica (Thunb.) Lindl.) cv. Golden Nugget en los últimos cuatro estadios secuenciales de madurez. Existe controversia sobre el patrón respiratorio del níspero (Eriobotrya japonica [Thunb.] Lindl.). Con el fin de aportar información sobre este aspecto, frutos del cv. Golden Nugget entre 50-70 g, fueron cosechados en cuatro estadios de madurez; verde (BBCH 709), quiebre de color (BBCH 801), amarillo (BBCH 807), y anaranjado (BBCH 809). Los parámetros evaluados en cada estadio fueron: sólidos solubles, acidez titulable, relación sólidos solubles acidez, respiración, generación de etileno y la actividad de las enzimas pectin metil esterasa (PME), peroxidasa, polifenoloxidasa (PPO), poligalacturonasa (PG), y celulasa. Los resultados muestran que el etileno incrementó su concentración al momento de quiebre de color, lo cual no fue equivalente en el cambio de la tasa respiratoria. La actividad de la enzima peroxidasa se incrementó desde el color verde al quiebre de color, mientras que las enzimas PME, celulasa, y PG mostra