Effects of temperature on postharvest respiratory parameters and quality attributes of ackee (Blighia sapida Köenig) fruit arils during storage
1,2*Benkeblia, N. and 3Beaudry, R.M.
1Laboratory of Crop Science, Department of Life Sciences, Faculty of Science and Technology,
The University of the West Indies, Mona Campus, Kingston 7, Jamaica
2Laboratory of Tree and Aromatic Crop Research, The Biotechnology Centre, Faculty of Science
and Technology, The University of the West Indies, Mona Campus, Kingston 7, Jamaica
3Department of Horticulture, Michigan State University, East Lansing, MI 48824-1325, United States
Abstract
The effect of temperatures on the rate of O2 uptake (RRO2) and CO2 production (RRCO2), the Q10 and activation energy (Ea) of respiration, the respiratory quotient (RQ), the rate of ethylene production, the colour and visual quality attributes of ackee (Blighia sapida Köenig) fruit arils “cheese” variety were measured. RRO2 averaged 0.26, 0.63, and 0.96 mmol kg-1 h-1 and RRCO2 averaged 0.22, 0.55, 0.90 mmol kg-1 h-1 and ethylene production averaged, 47.5, 50.2 and 51.9 nmol kg-1 h-1 at 5, 15 and 25°C, respectively. Neither RRO2 nor RRCO2 correlated with ethylene production. The RQ of arils varied from 0.89 to 1.0 and the Q10 varied from 1.8 to 2.0, while the Ea ranged from 40.4 to 51.6 kJ mole-1. Decay and quality loss were rapid at temperatures above 15°C. When kept under chilling temperature (3°C for 20 days with or without subsequent removal to 25°C), ackee arils showed severe chilling injury symptoms. Decay was also accelerated by the removal to 25°C. Collectively, the data indicate that ackee fruit aril storage is limited to temperatures between 5°C and 15°C.
測定了不同溫度對ackee(Blighia sapida Kóenig)果實假種“cheese”品種吸氧率(ROR2)和產CO2率(RRCO2)、呼吸Q10和呼吸活化能(Ea)、呼吸商(RQ)、乙烯生成率、顏色和視覺品質的影響。RRO2平均為0.26、0.63和0.96mmol kg-1h-1，RRCO2平均為0.22、0.55、0.90mmol kg-1h-1，乙烯平均產量分別為47.5、50.2和51.9nmol kg-1h-1，溫度分別為5、15和25℃。RRO2和RRCO2均與乙烯生成無關。假種皮的RQ為0.89～1.0，Q10為1.8～2.0，Ea為40.4～51.6kj mole-1。在高于15℃的溫度下，和質量損失很快。當在低溫下(3℃下保存20天，隨后或不移除至25℃時)，青貯假種皮表現出嚴重的冷害癥狀。去除到25°C也會加速腐爛。總體而言，數據表明，ackee水果假種皮的貯藏溫度限制在5°C到15°C之間。
Keywords：Respiration,Ethylene,Q10,chilling injury,Blighia sapida
Respiration rates (RRO2 and RRCO2) assessment
The respiration rates (RRO2 and RRCO2) were determined using a static respirometer method as described by Benkeblia et al. (2000). Detached arils (200 ± 10 g) were placed in 1-L glass jars previously equilibrated at the required temperature and stored in temperature-controlled rooms (5 and 15°C) and controlled room temperature (25°C). For each temperature, jars were closed and the gas composition of each jar analysed at seven time points 0, 1, 2, 3, 4, 5, and 6 h to be able to select only those data associated with aerobic respiration as of oxygen is depleted in the jar and CO2 increases. To also avoid changes in pressure in the jars that can occur following the removal of multiple gas samples, the air sample for composition analysis was circulated through the analyser (model ICA250, International Controlled Atmosphere Ltd Instrument Division, Kent, UK) and back to the chamber. The sampling duration was 2 min. Respiration rates (RRO2 and RRCO2) were calculated by fitting O2 depletion and CO2 accumulation data for the seven time points with a linear regression and expressed as mmol kg-1 h-1 O2 and depletion did not exceed 4% during the holding period. For each respiration measurement, three jars were used and measurements were duplicated.
采用Benkeblia等人描述的靜態呼吸儀法測定呼吸速率(RRO2和RRCO2)。(2000年)。將分離的假種皮(200±10 g)放置在1 L玻璃罐中，先前在所需溫度下保持平衡，并儲存在溫度控制室(5和15°C)和控制室溫度(25°C)中。對于每種溫度，罐子都是關閉的，每個罐子的氣體成分在7個時間點(0、1、2、3、4、5和6h)進行分析，以便能夠僅選擇與氧氣在罐子中耗盡和二氧化碳增加時的有氧呼吸相關的數據。為了避免在去除多個氣體樣本后可能發生的罐內壓力變化，成分分析用空氣樣本通過分析儀(model ICA250, International Controlled Atmosphere Ltd Instrument Division, Kent, UK)循環，然后返回到試驗箱。采樣持續時間為2分鐘。通過線性回歸擬合7個時間點的氧氣消耗和二氧化碳積累數據計算呼吸速率(ror2和RRCO2)，表示為mmol kg-1h-1o2，在保持期間，消耗不超過4%。每次呼吸測量使用三個罐子，重復測量。
Ethylene production assessment
Ethylene production was determined by the same method described for the respiration rate but using a different gas analyser (model ICA56, International Controlled Atmosphere Ltd Instrument Division, Kent, UK). Ethylene production was calculated by fitting ethylene accumulation data for the seven time points with a linear regression and expressed as nmol kg-1 h-1. For each ethylene measurement, three jars also were used and measurements were duplicated.
乙烯的產生是用與呼吸速率相同的方法測定的，但使用的是不同的氣體分析儀(model ICA56, International Controlled Atmosphere Ltd Instrument Division, Kent, UK)。用線性回歸擬合7個時間點的乙烯積累數據，計算乙烯產量，用nmol kg-1h-1表示。對于每次乙烯測量，也使用三個罐子，并重復測量。
