| 摘要： 本研究係針對屏東縣長治鄉林氏農民所栽植之紅龍果(Hylocereus undatus Britt. ＆ Rose)，包括紅肉種及白肉種果實為材料，探討紅龍果果實發育期間之理化變化，果實採後生理及貯藏(0-25℃)包裝(裸果、PE袋旋口、PE袋密封、乙烯吸收劑配合PE袋密封及舒果袋配合PE袋密封)與低溫檢疫處理(0℃,15日)對果實品質、貯藏壽命之影響，以及果實糖類組成份等進行一系列探討。結果顯示，白肉種及紅肉種紅龍果不論在果實發育期間或貯藏期間，其呼吸型態均屬非更年型的果實，兩品種紅龍果在果實發育初期(10-20日)，呼吸率有增加之趨勢，爾後隨著果齡的增長而下降，白肉種紅龍果以果齡15日之果實呼吸率為最高，而紅肉種為果齡20日者。就果實乙烯產生率之變化，白肉種紅龍果之果齡愈小則乙烯產生率愈高，爾後隨果齡增加而呈下降的趨勢，紅肉種之乙烯產生率與白肉種紅龍果有類似的變化趨勢，但紅肉種紅龍果的乙烯產生率高於白肉種紅龍果，在果實發育過程均無呼吸呼吸高峰及乙烯高峰出現。紅龍果果實在發育期間的鮮重、果長、果寬及體積等生長趨勢的變化均呈典型單S曲線，果實可溶性固形物(TSS)、果肉百分率、果肉及果皮乾物重均隨著開花後天數的增加而增高，而果實硬度、可滴定酸含量(TA)、果皮厚度、果皮百分比及果肉含水率均隨果實發育而呈下降趨勢。果實的色澤變化部分，在果實開始轉色時(25日)，果實亮度及色相角度快速降低，而色彩濃度則呈上升之趨勢，兩品種紅龍果成熟時果皮皆呈現紅色色澤。紅龍果果實以PE袋配合舒果袋密封包裝後，能有效延長果實貯藏壽命，白肉種紅龍果於0℃貯藏之果實貯藏壽命為37日，而紅肉種為35日，雖果實有輕微寒害，但仍具商品價值；而5℃貯藏之果實無寒害徵狀，白肉種紅龍果果實貯藏壽命可達31日，而紅肉種為27日。低溫貯藏之(0-5℃)紅龍果果實，TA含量隨貯藏期間的增長而呈緩慢的增加，而果實糖酸比則成下降之趨勢，在10-25℃貯藏紅龍果，果實TSS、TA及維生素C含量均隨貯藏天數的增加而降低，糖酸比則隨貯藏天數及貯藏溫度的增加而快速上升。包裝處理對果實貯藏品質之影響不明顯。白肉種及紅肉種紅龍果成熟果實之可溶性固形物(TSS)含量以果心部位較高，可滴定酸(TA)含量較低，而近果皮部位之TA含量較高，因此果心部位之糖/酸比高，而近果皮部位之糖/酸比較低。果實中主要糖類為果糖、葡萄糖及麥芽糖，而檢驗不出有蔗糖成分。紅肉種及白肉種紅龍果果實經低溫檢疫(0℃,15日)處理後，移至10℃及25℃貯藏，果實移至10℃經6日貯藏後，外觀有寒害症狀產生，而果實硬度、pH值、糖酸比均較持續在0℃貯藏之果實有提高之趨勢，而回溫25℃貯藏之果實易腐敗。Two varieties of dragon fruits (Hylocereus spp.) `cv. white pulp' and `cv. red pulp' from Lin’s Farm in Changchih, Pingtung were used in this study. A series of studies were conducted to elucidate the physicochemical changes, sugar contents during fruits development, postharvest storage (0-25℃). Five packaging types were compared in this study: unpackaged, tensional PE bag, sealed in polyethylene (PE) bag, sealed in PE bag containing ethylene absorbents, and sealed in PE bag containing polystyrene net sleeve (PNS). Quarantine of quality at low temperature (0℃, 15 days) was investigated. The results showed that the respiration rate of both white and red pitaya fruits were typical non-climacteric pattern during fruits development and post harvest storage. The respiration rate of both varieties was increased at initial growth period (10-20 days), and respiratory rate was subsequently decreased in later growth period. The white pitaya respiration rate was peak at 15th day after onset of fruit, but the red pitaya was 20th day after onset of fruit. The ethylene production rate was high at the early stage and decreased gradually as the pitaya fruit increase in size. The ethylene production rates of the red pitaya were higher than the white pitaya. In addition, the ethylene production rates of white pitaya and red pitaya were both low at later growth period. No significant climacteric respiration or ethylene peak observed during fruit development. Results showed that the growth curves of fresh weight, length, width and volume of dragon fruits development were in a typical single sigmoid pattern. The ratio of fruits total soluble solids (TSS), fruit flesh percent, dry matter of fruit flesh and seedcase increased progressively with the days after bloom. However, the firmness, titratable acidity (TA), the skin of fruit thickness and percent, and fruit flesh contain water percent ratio decreased with the increased of the duration of growth. The fruits lightness and hue angle values decreased with color changed on 25 days, but chrome values increased. The skin color of both pitaya was red. The storage life of the white pitaya fruits with sealed in PE bag containing PNS was 37 days at 0℃, the red pitaya fruits was 35 days, while the fruits still possessing commercial value. The dragon fruits stored at 5℃ did not show symptoms of chilling injury. The storage life of the white pitaya fruits was 31 days at 5℃, but the red pitaya fruits were 27 days. The TA content of dragon fruits increased with the increase of storage duration at 0-5℃. The TSS/acidity ratio of fruits decreased with the increase of storage duration at 0-5℃. The dragon fruit quality in TSS, TA and retained the vitamin C content decreased with the increase of storage duration at 10-25℃. The TSS/acidity ratio of fruits increased with the increase of storage duration at 10-25℃. Various packaging methods had no impact to the fruit quality during post harvest storage period. The contents of TSS were high in core of the mature fruits of `cv. white pulp' and `cv. red pulp’, but the contents of TA were low. Therefore, the TSS/acidity ratio was high in core of the fruits, but the TSS/acidity ratio was low in near skin of fruit. The major sugars of dragon fruits were fructose, glucose and maltose, no sucrose. When the `cv. White Pulp' and `cv. Red Pulp' fruits were first stored at low temperature quarantine treatment (0℃, 15 days), then transferred to 10℃ and 25℃, the chilling injury on the fruit surface was observed at 10℃ for six days. The firmness, pH and TSS/acidity ratio of dragon fruits increased with the increase of storage temperature at 0℃, and the stored pitaya fruits appeared corruptible at 25℃. |
頁面載入中請稍後...