| 摘要： 本研究乃針對三種番木瓜（Carica papaya L.）栽培品種，包括‘台農二號’（ ‘Tainung No.2’）、‘日陞’（‘Sunrise’）、及新選育但尚未命名之‘SR-mu’番木瓜品系為材料，探討番木瓜果實發育期間之理化變化及採收後之生理、生化變化、貯藏條件以及1-MCP處理、熱處理之反應等，進行一系列之探討。 結果顯示，番木瓜果實發育期間鮮重、體積、果長及果寬等方面的變化均呈典型之單S型曲線。果實之果肉厚度、種子重、乾物重、維生素C、可溶性固形物（TSS）及糖/酸比等，皆有隨授粉後天數增加而增加之趨勢，而硬度、含水量及果皮（肉）色相角度等，則是隨授粉後天數增加而下降。 番木瓜果實（‘台農二號’、 ‘日陞’及 ‘SR-mu’品系）均屬更年性果實。此三個栽培品種之果實在各個發育時期，採收後在20℃皆有呼吸高峰和乙烯高峰出現，只是出現的時間和產生率有所不同。以果齡130天為例，‘台農二號’其呼吸高峰在第5天出現，吸呼率為42.13 mg CO2/kg-hr，乙烯高峰在第6天出現，乙烯產生率為3.87 µl/kg-hr。‘日陞’栽培品種之呼吸高峰在第4天出現，呼吸率為40.96 mg CO2/kg-hr，乙烯高峰在第7天出現，乙烯產生率為4.82 µl /kg-hr。‘SR-mu’品系之果實，其呼吸高峰在第6天出現，呼吸率為42.35 mg CO2/kg-hr，乙烯高峰在第7天出現，乙烯產生率為3.61 µl /kg-hr。此外，乙烯更年峰出現之時間，一般有較呼吸更年峰晚1-2天出現之趨勢。 此三個栽培品種在授粉後105天前，果實果腔氣體均測不到CO2和乙烯濃度，一直到授粉後120天時，才明顯測到‘日陞’果腔中的CO2濃度為5.92 %，乙烯濃度為0.06 ppm；‘台農二號’為3.98 %，乙烯濃度為0.02 ppm；‘SR-mu’為1.32 %，但在授粉後130天才測得到‘SR-mu’（品系）乙烯濃度為0.09 ppm；此三栽培品種果腔CO2和乙烯濃度在授粉後130-135天，達到最高。爾後果實成熟度愈高，其CO2和乙烯濃度反而下降。 不同成熟度之‘台農二號’番木瓜果實，貯藏溫度愈高，呼吸率愈高，且呼吸更年上升之時間愈早，乙烯產生率亦呈類似之趨勢。此外，果實成熟度愈高，其呼吸及乙烯高峰出現之時間亦愈早，且在更年峰時之呼吸率及乙烯產生率，亦有成熟度愈高，其產生率愈高之趨勢。 ‘台農二號’或‘日陞’番木瓜果實在不同溫度（5-25℃）之貯藏期間，均以未加任何包裝處理之裸果失重最嚴重，在20-25℃經9天，失重即達11-15 %左右，而以PE袋密封及袋內加乙烯吸收劑之包裝處理失重最小（約2-4 %）。隨著貯藏溫度之增加，失重會愈快且愈明顯，故降低貯藏溫度可減緩果實之失重程度。另外，不同包裝會影響果實之貯藏壽命，以5-10℃為例，台農二號果實以PE袋密封包裝或內附乙烯吸收劑之貯藏壽命（25-26天）較無包裝處理者長（21天），而‘日陞’果實之貯藏壽命，則分別為22-24天及19-21天。番木瓜果實品質（TSS及TA）之變化與包裝處理並無明顯關係存在，但利用PE袋密封包裝或袋內加乙烯吸收劑，可維持維生素C含量、延緩果實果皮轉黃及果實硬度下降。然而，番木瓜果實在5℃貯藏14天，會有凹陷和水浸狀之寒害症狀，不適於番木瓜果實之貯藏，故在番木瓜果實之貯運上，貯藏溫度建議以10℃為宜。 ‘台農二號’番木瓜果實經1-MCP處理，其呼吸率及乙烯產生率均較無1-MCP處理者低，1-MCP處理濃度愈高（0.1→5.0 ppm），抑制呼吸作用及乙烯產生率愈明顯，且呼吸和乙烯高峰出現的時間，亦會被延遲。另外，1-MCP處理也能抑制PE和PG之酵素活性，1-MCP處理濃度愈高（1.0 →5.0 ppm），抑制PE或PG酵素活性之效果愈明顯。1-MCP處理者，經7天（25℃），再以ethephon（1,000 ppm）處理，仍無法提高PE及PG活性。 ‘台農二號’番木瓜果實，在貯藏前熱處理，其呼吸率和乙烯產生量，會隨著熱處理溫度（56→60℃）與時間（8→16 sec.）之增加而下降，且達到呼吸及乙烯更年峰之天數亦會被延緩。熱處理溫度愈高及時間愈長，其果實硬度愈高，故得知貯藏前熱處理（56-60℃，8-16 sec.）可明顯抑制番木瓜果實之軟化。而貯藏前熱處理對果實內在品質（TSS、TA、pH、Vit. C）及果實果皮（肉）色澤（亮度、色彩濃度、色相角度）並無顯著之影響。A series of studies were conducted to elucidate the physico-chemical changes during fruit growth and development, and postharvest physiology and storage of three cultivars of papaya fruits (Carica papaya L.), named ‘Tainung No.2’, ‘Sunrise’, and ‘SR-mu’ (a newly selected line and has yet to be named), and their responses to 1-methylcyclopropene (1-MCP) and heat treatments. Results showed that the growth curves of fresh weight, volume, length, and width of fruits were in a typical single sigmoid pattern. The fresh thickness, seed weight, dry matter, vitamin C, total soluble solids (TSS) and sugar/acid ratio increased progressively with the days after pollination. However, the firmness, moisture content of fruit, and hue angle of peel and flesh decreased with the fruit growth and development. Papaya fruits, including ‘Tainung No.2’, ‘Sunrise’ and‘ SR-mu’ cultivars, are typical climacteric fruits. During the growth and development, fruits at different stages (ages) all exhibited climacteric respiratory and ethylene production peak at 20 oC after harvest. The only difference will be the time of the peaks appeared and the production rate. For example, the 130-day old fruits, the peak of respiration of ‘Tainung No.2’ fruits appeared on the fifth day at the rate of 42.13 mg CO2/kg-hr and the peak of ethylene production was found on the sixth day with a production rate of 3.87 µl/kg-hr. The peak of respiration of Sunrise fruits appeared on the fourth day at the rate of 40.96mg CO2/kg-hr and the peak of ethylene production was found on the seventh day with a production rate of 4.82 µl/kg-hr. The peak of respiration of ‘SR-mu’ fruits appeared on the sixth day at a rate of 42.35 mg CO2/kg-hr and the peak of ethylene production was also found on the seventh day with a production rate of 3.61µl/kg-hr. The peak of climacteric ethylene production usually appeared one to two days later than the peak of climacteric respiration. In these three cultivars, the concentrations of CO2 and ethylene in fruit cavities were not detectable before 105 days after pollination. Only until 120 days after pollination, CO2 and ethylene were clearly detected in the Sunrise fruits at a concentration of 5.92 % and 0.06 ppm, respectively, and in ‘Tainung No.2’ fruits were 3.98 % and 0.02 ppm, respectively. Although CO2 was also detected in ‘SR-mu’ at a concentration of 1.32 % in 120 days after pollination, but ethylene was detectable at a concentration of 0.09 ppm in 130 days after pollination. CO2 and ethylene concentrations reached their peaks in the fruit cavity of the three cultivars in 130-135 days after pollination. Afterwards, the more mature the fruits became, the lower the concentrations of CO2 and ethylene detected in fruit cavities. At the different maturities of papaya fruits (‘Tainung No.2’), the respiration rate of fruits increased with the increase of the storage temperature, and the time for climacteric rise of respiration and ethylene production were shortened. In addition, the higher the maturity of the fruits, the time for the climacteric respiration and ethylene production peak were earlier, and the rate at peak were higher with the more mature fruits. When the fruits of ‘Tainung No.2’ and ‘Sunrise’ were stored at 5-25oC, the weight loss in naked, unpackaged fruits was most serious; reaching 11-15 % in nine days storage. The weight loss was the least (about 2-4 %) in the fruits packed with sealed PE bag or sealed in PE bags containing ethylene absorbents. The weight loss significantly increased with the increase of the storage temperature. Therefore, lowering the storage temperature would reduce the weight loss. Different packaging methods affected storage life of fruits. Using 5-10o C as example, the fruits of ‘Tainung No.2’ packed in sealed PE bags or sealed PE bags containing ethylene absorbents significantly extended the storage life to 25-26 days compared to unpacked fruits with 21 days of storage life, whereas the ‘Sunrise’ fruits were 22-24 days and 19-21 days, respectively. The fruit qualities in TSS and titratable acidity (TA) were not affected by different packaging methods. Fruits packed in sealed PE bags or sealed in PE bags containing ethylene absorbents retained the vitamin C content and delayed fruit peel yellowing and softening. However, papaya fruits storing at 5oC for 14 days exhibited surface pitting and water soaked symptoms of chilling injury; therefore, papaya fruits were not suitable for storing at 5oC. It is suggested that the papaya fruits should be stored at 10oC during storage and transportation. The respiration and ethylene production rate of ‘Tainung No.2’ fruits subjected to 1-MCP treatment were lower than those of the fruits not subjected to the treatment. The higher the concentration of 1-MCP treatment at 0.1-5.0 ppm, the inhibition of the respiration and ethylene production was more pronounced. Also, the time for the peaks of climacteric respiration and ethylene production was delayed. In addition, the 1-MCP treatment also inhibited the enzyme activities of pectinesterase (PE) and polygalacturonase (PG). The higher the concentration of 1-MCP treatment at 1.0-5.0 ppm, the inhibition of the enzyme activities of PE and PG were pronounced. Even at seven days after 1-MCP treatment, the 1-MCP treated fruit retreated with ethephon (1,000 ppm), the activities of PE and PG were not recovery. The prestorage heat treatment of papaya fruit (‘Tainung No.2’) at 56-60 oC and 8-16 sec. decreased the respiration and ethylene production rate. The days required to reach the climacteric peak of respiration and ethylene also delayed. The flesh firmness of fruits with prestorage heat treatment were significantly higher than those of non-heated fruits. The higher treated temperatures (56-60 oC) and longer duration (8-16 sec.), the higher flesh firmness of fruits. Therefore, the prestorage heat treatment was significantly inhibited the softening of papaya fruits. Prestorage heat treatment did not significantly affect the fruit qualities in terms of TSS, TA, pH, and vitamin C, and the color of the fruit (peel and flesh) in terms of brightness, color saturation and hue angle. |
頁面載入中請稍後...