Philippine E-Journals

Respiration Rate and Respiratory Quotient of Musa Acuminata (AAA Group) Bananas at Various Environmental Conditions

Anthony Gerard G. Santos | Maria Carla F. Manzano | Enrique M. Manzano

 

Abstract:

In this study, the respiratory quotient (RQ) and respiration rate (RR) of Lakatan [Musa acuminata (AAA group)] bananas were obtained for 14 days using a flowthrough system under three environmental conditions; in particular, nonairconditioned, airconditioned, and refrigerated with corresponding temperatures of 33°C ± 2°, 24°C ± 2°, and 7°C ± 2°, respectively. The Lakatan bananas were enclosed in glass gas-tight chambers and the carbon dioxide CO2 and oxygen O2 concentrations in the chambers were measured daily for 14 data. From the measured CO2 and O2 concentrations, values of RQ and RR were calculated. Results show that CO2 concentrations generally increased during the ripening stage, from day 1 to 4, then decreased over time. Highest CO2 variations, ranging from ~0.45 to ~0.83, were observed in bananas kept at 33°C ± 2°; while CO2 variations were minimal for those stored at 24°C ± 2°. The O2 concentrations were fairly constant over 14 days. Further, the O2 concentrations measured from bananas kept at 7°C ± 2° were higher than those kept at 33°C ± 2°. The RQ values were found to decrease over time under all three temperature conditions. All the RQ values were less than one, which implies that lipid was the main metabolic substrate being oxidized all throughout the 14 days. It was also observed that the RQ values remain almost constant from day 7 to 14, and were higher, by as much as 13.1%, in bananas kept at 33°C ± 2° as compared to those at 7°C ± 2°. Results show that storage temperature is a major factor in measured RQ values. Measurement of RQ and RR these values could be used to determine the stage of fruit development and determine the optimum conditions to prolong the shelf-life of fruits.