摘要: 本論文針對宜蘭地區‘中山月拔’番石榴進行下列之研究,包括:果實之生育調查及採收成熟度;不同採收成熟度及貯藏溫度對其果實呼吸速率、乙烯生成、果實品質與貯藏力之影響;以及採後1-甲基環丙烯處理對番石榴果實腐爛率及果皮色澤之影響。冀望對宜蘭地區番石榴產業之研究與推廣有所助益。以宜蘭縣頭城鎮林姓果農(北緯+24° 51' 49.48"",東經+121° 48' 26.63"")所生產的‘中山月拔’番石榴為試驗材料進行試驗。 果實之生長曲線分為3個階段,果實發育第1階段,生長快速;第2階段,生長趨於和緩;第3階段,果實迅速地生長,此期間橫徑增加速度較縱徑增加速度快,果實生長模式呈雙S型。果形指數發育初期大於1,果實為長圓形,爾後皆小於1,接近扁圓形。每週落果率及累積落果率從花後13至76天皆低於15%,花後83天至104天期間大量落果,並在104天達100%。前述經生育調查的果實,於花後34、62、76、83、90及97天採收,果重隨著花後天數的增加而上升,花後76天硬度為65 N至花後97天迅速下降至10 N。果皮L值隨花後天數的增加而上升,但在花後97天降低。花後90天果皮a*值最高,花後83及97天最低,差異顯著。果皮b*值隨花後天數的增加而上升。花後83至97天總可溶性固形物含量隨花後天數增加而上升,花後97天(11°Brix)最高與花後83 (9°Brix)及90天(9°Brix)差異顯著。可滴定酸含量、糖酸比及抗壞血酸含量皆沒有顯著差異。基於果實生育特性、果品條件要求及銷售經濟效益之考量,建議之採收成熟度為花後97天。 果實鮮重隨採收成熟度(花後84、90、96及102天)的增加而上升,硬度則反之。花後90天之果皮L與a*值最高;果皮b*值則是花後102天最高。花後84天之總可溶性固形物最低,102天者最高。可滴定酸含量隨採收成熟度的增加而下降。抗壞血酸含量則是以花後96天最高,花後90天最低。採收成熟度(花後84、90、96及102天)果實貯藏於20℃和5℃歷時12天,結果顯示於20℃貯藏9天後,以花後102天果實腐爛率最高(100%)。花後84、90及96天處理組果皮L值在貯藏期間先下降後上升,花後102天果實則是隨貯藏時間增加持續上升,於貯藏12天後些微下降;花後102天之果皮a*值於貯藏第6天即由負轉為正值,而花後90及96天者於貯藏第9天由負轉為正值,花後84天者則於貯藏第12天才由負值轉為正值;b*值隨貯藏時間增加持續上升。隨採收成熟度的增加果實硬度、總可溶性固形物含量及抗壞血酸含量皆下降。5℃貯藏期間,花後102天果實經貯藏9天後腐爛率最高(66%)。花後84、90及96天之果皮L值皆於貯藏3天後明顯下降,但花後102天者初期沒有明顯變化,僅於貯藏9天後下降;各處理組果皮a*值於貯藏期間皆未轉為正值;各處理組b*值沒有明顯變化,僅以花後84天隨貯藏時間增加下降。果實硬度方面,隨採收成熟度的增加而下降。各處理組之可溶性固形物含量皆無顯著變化,惟花後102天者隨貯藏時間增加而下降。可滴定酸含量僅以花後84天明顯高於其它處理組。抗壞血酸含量隨成熟度增加而下降。建議之採收成熟度為花後96天。 花後84天果實呼吸速率於貯藏第8天達到更年高峰,隨花後天數增加至102天,果實呼吸率更年高峰於貯藏第2天到達。而乙烯高峰方面,花後84天果實於貯藏第8天到達,隨花後天數增加至102天,乙烯高峰於貯藏第4天到達。貯藏溫度對‘中山月拔’呼吸速率與乙烯生成的影響,結果顯示,貯藏於25 ℃下之果實呼吸速率於第3天開始上升,而 20℃下之果實呼吸速率隨貯藏天數增加而上升,二者皆在第5天達到最高峰。貯藏於5及10℃下的處理組,貯藏期間直至7天前呼吸速率皆趨於平緩,直至回溫第1天時,呼吸速率開始攀升。貯藏於25℃下的處理組乙烯生成於第1天開始上升,第2天時達到最高峰。貯藏於20℃下的處理組,於3天達到最高峰,爾後緩緩下降。貯藏於5及10℃下的處理組,貯藏期間直至7天前乙烯生成皆趨於平緩,直至回溫第1天時,乙烯生成達到高峰,而回溫後原貯藏於5℃之果實其果皮褐化較10℃者嚴重,因而推斷貯藏於10℃之果實有最佳的貯藏壽命。 將綠熟果實放置於20℃下,以濃度0、300、600 nL˙L−1 1-MCP處理12小時,隨著1-MCP濃度的增加而腐爛率降低,以600 nL˙L−1處理最低,300 nL˙L−1次之,差異顯著。失重率隨著貯藏天數的增加而上升,但差異不顯著。各處理組果皮的L值先上升,在第4天後下降。無1-MCP處理者及300 nL˙L−1者a*值分別於第4天和第5天由負值轉為正值,而600 nL˙L−1者至第6天a*值仍為負值。無1-MCP處理者與300 nL˙L−1及600 nL˙L−1之b*值,僅於貯藏第2天至5天有顯著差異,但300及600 nL˙L−1者間差異不顯著。In this thesis, ‘Jong-Shan Yueh Bar’ (Psidium guajava L.) from Ilan was adopted for the following study, including fruit growth and development and harvest maturity, the impact of harvest maturities and storage temperatures on the fruit’s respiration rate, ethylene production, fruit quality and storability, and the influences on fruit decay rate and peel color of guava by 1-Methylcyclopropene (1-MCP) postharvest treatment. The study is expected to contribute to the study and promotion of the guava industry. The fruit materials used in this experiment were grown by a fruit farmer Mr. Lin in Toucheng, Ilan (north latitude+24° 51' 49.48"", east longitude +121° 48' 26.63""). The growth curve of the fruit can be divided into three stages: first stage: fruit development significantly increased; second stage: steady growth; third stage: rapid fruit growth, during which period the transversal diameter increases at a faster length than the longitudinal diameter. Fruit growth follows a double-sigmoid curve. The fruit shape index during the early development is greater than 1, indicating that the fruit has an elongated shape; the fruit shape index subsequently becomes less than 1, indicating the shape as oblate sphere. The fruit drop rate per week and accumulate fruit drop rate were lower than 15% from 13 to 76 days after anthesis (DAA), a significant fruit drop occurred 83 to 104 DAA, reaching 100% on 104 DAA. The abovementioned fruit in the growth and development was harvested on 34, 62, 76, 83, 90, and 97 DAA. That increases days after anthesis increased the mass of the fruit. The fruit firmness quickly dropped from 65N (75 DAA) to 10 N (97 DAA). The L value of the peel color increased as the number of days after anthesis increased, but decreased on 97 DAA. The a* value of the peel color was the highest on 90 DAA and it was the lowest on 83 and 97 DAA, thus reaching significant differences. The b* value of the peel color increased as the number of days after anthesis increased. The total soluble solids content from 83 to 97 DAA increased with increases in the number of days after anthesis, with 97 DAA (11 °Brix) being the highest and 83 DAA (9 °Brix) and 90 DAA (9 °Brix) reaches significant differences. The titratable acidity content, sugar-acid ratio, and ascorbic acid content showed no significantly different. In consideration to the characteristics of fruit growth and development, fruit quality requirements, and economic benefits, it is recommended that the 97 DAA be selected as the harvestable maturity. The mass of the fruit showed an upward trend with increase in harvest maturity (the number of days after anthesis), but the fruit firmness showed the opposite results. The fruit peel color on 90 DAA had the highest L and a* values, the b* value of the peel color was the highest on 102 DAA. The total soluble solids content on 84 DAA was the lowest and the highest on 102 DAA. That an increase harvest maturity decreased the titratable acidity content. The ascorbic acid content was the highest in 96 DAA and was the lowest in 90 DAA. As for harvest maturity (84, 90, 96, and 102 DAA), the results of the fruit stored under 20 and 5℃ for 12 days showed that after 9 days under 20℃, the decay rate of the fruit 102 days after flowering was the highest (100%). The L value of the treatment group on day 84, 90, and 96 first decreased and then increased, on 102 DAA, the fruit continued to increase as storage time increased, but it slightly decreased after 12 days of storage; the a* value of the peel color on 102 DAA turned from a negative value to appositive value on the sixth day of storage. On the other hand 90 and 96 DAA turned from negative values to positives values on day ninth; 84 DAA turned from a negative value to a positive value on day twelfth; the b* value of the peel color increased in the storage period increased. With increases in harvest maturity, the fruit firmness, total soluble solids content, and ascorbic acid content all decreased. During the period of storage at 5℃,the fruit on 102 DAA and stored for 9 days had the highest decay rate (66%). The L values of the peel color on 84, 90, and 96 DAA all significantly decreased after storage for 3 days, but the fruit on 102 DAA showed no significant changes, except for the fruit stayed for ninth days that decreased; the a* values of the peel color in various treatment groups did not turn to positive values during the storage period; all the treatment groups showed no significant changes in b* values, but the 84 DAA was decreased during storage. In terms of fruit firmness, it decreased with an increase in harvest maturity. The total soluble solids content of various treatment groups showed no significant changes, except for the one stored for 102 DAA that decreased. As of the titratable acidity content only 84 DAA was significantly higher than the other treatment groups. The ascorbic acid content decreased with increases in maturity. It is recommended that the 96 DAA be selected as the maturity for harvest. On 84 DAA, the respiration rate of the fruit climacteric peaked on day eighth. As the days increased to 102 DAA, the respiration rate reached the climacteric peak on the second day of storage. As for the peak of ethylene, the fruit 84 DAA also peaked on the eighth day of storage. As the number of days after anthesis increased to 102 DAA, the peak of the fruit ethylene was reached on the fourth day. As for the impact of storage temperature on the respiration rate and ethylene production of ‘Jong-Shan Yueh Bar’ guava fruit, findings show that the respiration rate of the fruit stored under 25℃ began to increase on the third day, while the respiration rate of the fruit stored under 20℃ increased with increases in the number of storage days, both peaking on fifth day. For the treatment groups stored under 5 and 10℃, the respiration rates were steady until seventh day of storage, but the respiration rate began to increase on first day of temperature transfer to 20℃. The ethylene production of the treatment group stored under 25℃ began to increase on first day and peaked on second day. The treatment group stored under 20℃ peaked after 3 days and gradually decreased afterwards. The treatment groups stored under 5 and 10℃ showed steady ethylene production until seventh day of storage, on the first day of temperature transfer to 20℃, the ethylene production reached the peak. While fruit peel browning was more serious in the fruit stored under 5℃ compared to the fruit peel stored under 10℃, thus the inference that the fruit stored under 10℃ had the best shelf life. The harvested mature green fruits were treated using 1-methylcyclopropene (1-MCP) of varying concentrations (0, 300 and 600 nL˙L−1) under 20°C for a period of 12 hours. The results showed that an increase in 1-MCP concentration decreased the decay rate, where the 600 nL˙L−1 1-MCP featured the lowest decay rate, which was followed by the 300 nL˙L−1 1-MCP, and significant differences were observed. The weight loss percentage increased with the storage duration, but no significant differences between three concentrations. An increase in the storage period (after fourth day) decreased the L value. For guavas treated using the 0 nL˙L−1 or 300 nL˙L−1 1-MCP, the a* value moved from negative to positive on the fourth and fifth day, respectively. For guavas treatment using the 600 nL˙L−1 1-MCP, the a* value remained in the negative even on the sixth day. Concerning the b* value for guavas processed using the 0 , 300, and 600 nL˙L−1 1-MCP, significant differences were observed only between the second and fifth day, and the difference between the 300 nL˙L−1 or 600 nL˙L−1 1-MCP were no significant differences. |