番木瓜果實生長發育之理化特性探討

Studies on the Physico-Chemical Changes of Papaya ( Carica papaya L. ) Fruits during Growth and Development

本研究主要針對目前本省栽培面積最廣之‘台農二號’品種及品質優良之‘日陞’與農委會種苗改良繁殖場屏東種苗研究中心新選育但尚未命名之‘SR-mu’全兩性品系，在果實生長發育期間之果實理化特性之變化，進行一系列的探討。結果顯示，此三品種之果實生長發育期間，果實鮮重、果長、果寬及體積之變化，均呈單S型生長曲線（single sigmoid growth curve）。果實在授粉後90-110天左右即進入成熟期。果肉開始轉黃，種子轉褐，進而變黑。果肉之轉黃在果實生長發育其明顯早於果皮之轉黃。果實硬度在果實生長發育期間呈下降趨勢，而果實含水量在果實進入成熟期（授粉後90天以後）急速下降，乾物重則急速增加；至採收時（授粉後130天）含水量約86-87%，乾物質百分率約13-14%左右。果肉可溶性固形物含量（TSS），在幼果期極低（＜3°Brix），但在授粉後70天以後明顯增加，100天以後急速增加，至採收時以‘日陞’之TSS最高（13.4°Brix），‘SR-mu’及‘台農二號’較低約12°Brix。可滴定酸（TA）在幼果期（授粉後60天以前）均維持在較低水準（0.09-0.11%），爾後才逐漸增加，而於授粉後115天達到最高（0.22-0.26%），爾後再急速下降，至採收時約在0.15-0.17%左右。Vit.C含量則在授粉後隨著果實生長發育而逐漸增加，特別是在授粉後90天以後增加更為快速，至採收時Vit.C含量約在62-75mg／100g左右。從果實生長發育期間之果長、種子重、果長每日生長率、乾物重百分率、含水量、TSS及Vit.C含量之變化觀之，番木瓜在授粉後90天左右，均有一明顯之轉折點，顯示此階段是果實進入成熟期之關鍵點，此時果肉開始明顯轉黃，種子開始轉褐。從採收時（授粉後130天）之果實理化特性顯示，果重、體積、果肉厚度以‘台農二號’最大，其次為‘SR-mu’，而以‘日陞’最小；果皮及果肉之色相角度亦以‘日陞’最小（分別為64°；48°），色澤最為橙黃，而‘台農二號’（109°；54°）及‘SR-mu’（112°；51°）之色相角度較大，不若‘日陞’之橙黃。而果肉之TSS則以‘日陞’最高（13.4°Brix），明顯高於‘台農二號’及‘SR-mu’（11.9°Brix；12.0°Brix）；三個品種之果肉可滴定酸在0.15-0.17%之間，pH值在5.9-6.1之間，而Vit.C含量則以‘日陞’最高（74.5mg／100g）‘SR-mu’其次（68.7mg／100g）而以‘台農二號’最低（62.4mg／100g）。 A series of studies were conducted to elucidate the physico-chemical changes during fruit growth and development 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). Results showed that the growth of papaya fruit exhibits a single sigmoid growth curve in terms of increase in fresh weight, fruit length, width and volume. The growth and development of papaya fruit developed into maturation stage at 90-110 days after pollination (DAP) corresponding to the commencement of color changes of seed and flesh. The changes of color in flesh was much earlier compared to that in peel during the growth and development. The firmness of fruit declined slowly during the development of fruit. The fruit moisture content decreased and the percentage of dry matter increased rapidly after 90 DAP. The moisture content and percentage of dry matter at harvest(130 DAP)was 86-87%and 13-14%, respectively. The total soluble solids (TSS)was very low(