Determination of respiratory parameters of onion bulbs (Alium cepa L.) under total anozia
Noureddine Benkeblia
Abstracts, 10th International Controlled & Modified Atmosphere Research Conference, 4-7 April 2009, Antalya, Turkey. 80 pages.
2009
บทคัดย่อ
This works aimed to investigate the effect of total anoxia (100 N2) on the respiratory parameters of onion bulbs. Freshly harvest onion bulbs cv. Rouge Amposta obtained from organic farming were used for this experiment. Under total anoxia, Fermentative Index (FI) values were 0.048, 0.072 and 0.l4mmole CO2 kg-1h-l at 4, 10 and 20 °C, respectively. The fermentative process was temperature dependent and followed an Arrhenius-like equation (R2 = 0.992). The Q10 of onion bulb under anoxia was 1.93 and FI0 (fermentative index at 0°C) was estimated at 0.037 mmole CO2 kg-1h-l with an activation energy of 44,578 J mole-1. Moreover, the FI of the bulbs (in mmole CO2 kg-1h-l) was measured within 6 h after closing the vessels (jars). Beyond 24 h at 20°C, high CO2 production was likely to be due to anaerobic or aero/anaerobic microorganisms such as yeast and lactic acid bacteria. Furthermore, ethanol production under anoxia was also estimated and averaged <0.001, 0.55 and 0.79 pmole kg-1h-l at 4, 10 and 20°C, respectively. These results indicated that onion bulbs are less sensitive to anoxia and tolerated total anoxia for at least 24 hours.