番木瓜色彩讀值與主要色素含量之相關性分析

Correlation analysis of papaya (Carica papaya L.) chromaticity values and main pigment content

江淑雯(Shu-wen Chiang)

指導教授 ： 張龍生

國立臺灣大學/生物資源暨農學院/園藝學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.03128

摘要

茄紅素（Lycopene）、β-胡蘿蔔素（β-carotene）和β-隱黃素（β-cryptoxanthin）為番木瓜（Carica papaya L.）果實中主要含量的類胡蘿蔔素。類胡蘿蔔素是有效的天然抗氧化物，提升有益健康的果實內容物為番木瓜遺傳育種重要目標。增加類胡蘿蔔素含量的作物改良，需要遺傳的變異（genetic variability）以及一個快速且準確的方法來定量。在眾多的分析技術中，高效液相層析準確性高，其限制為必須在實驗室操作、專業的操作人員以及使用高毒性的溶劑。色度計的色彩讀值推估果實類胡蘿蔔素含量是為一種快速分析的替代方法。若番木瓜果肉之色彩讀值的變化與各類胡蘿蔔素含量之具有相關性，則會助益番木瓜之育種，惟至目前為止尚未有此方面之研究。利用‘台農2號’和台大選育品系在不同成熟期測量果肉L*、a*、b*值，同時利用高效液相層析法定量果實內含的茄紅素、β-胡蘿蔔素和β-隱黃素，推導最佳的迴歸公式。本文試圖藉迅速且容易的色度計之色彩讀值，推估番木瓜果實的類胡蘿蔔素含量，故在量測果實成熟時主要色素含量與色彩讀值之變化。結果顯示‘台農二號’的主要類胡蘿蔔素總和（茄紅素+β-胡蘿蔔素+β-隱黃素（ug．g-1））與a*值迴歸公式為－0.0006 a* 4 ＋ 0.0161 a* 3 － 0.0386 a* 2 + 0.2484 a* + 2.3905，期判定係數R2= 90.3%。台大選育品系的三種主要色素總含量（茄紅素+β-胡蘿蔔素+β-隱黃素（μg．g-1））公式為 4.2309（a*） - 42.239，具有92.4%的可信度。因此可在田間以便捷攜帶之色度計可準確預估番木瓜果實內主要類胡蘿蔔素含量變化。
民國六十年育成的一代雜交種‘台農二號’番木瓜（Carica papaya L.）是我國最主要的木瓜品種，其產量高又富含色素，且週年供應市場需求。在市場之‘台農二號’番木瓜果實變異極大；這可能是親本、栽培技術和氣候風土等影響。所以本研究以不同來源之‘台農二號’品種為材料，以RCBD二重複種在網室內，探討其重量、總可溶性固形物、果肉色澤以及果實色素含量的差異。結果顯示來源不同的‘台農二號’木瓜品種間其平均果重、總可溶性固形物、色相、茄紅素含量、維生素A含量有顯著差異。以氧自由基吸收能力分析（Oxygen radical absorbance capacity assay, ORAC）其果肉之總抗氧化力亦有差別，每克番木瓜果肉相當於1μmol Trolox的2.3~4.9倍。色度計量測之a*值與果肉總可溶性固形物在不同來源‘台農二號’中呈現直線的相關性，且色彩讀值a*值對總可溶性固形物之判定係數為51.4%，直線迴歸公式Brixo= 0.2604（a*）+ 2.7107。研究顯示所謂‘台農二號’番木瓜果實在相同的栽培管理下，確實存有遺傳的差異；也許可作為將來育種的材料或對往後選擇最適當之‘台農二號’推廣。

關鍵字

番木瓜 ； 色彩讀值 ； 類胡蘿蔔素 ； 相關性分析

並列摘要

Papaya (Carica papaya L.) fruits have values for abundant of lycopene, β-carotene, and β-cryptocanthin. They are potent natural antioxidants. To improve the healthy nutrients will benefit papaya breeding. Genetic manupulating fruit carotenoid content requires genetic variability and a rapid and accurate method of carotenoid quantitication. High-performance liquid chromatography (HPLC) is often used to quantify pigment contents; however, it is laborious. It requires skilled labor, and use highly toxic solvents. Fruit carotenoids estimation measured by colorimeter has been proposed as an alternative rapid method. Regrssion of the main carotenoids contents of papaya on the color readings has not been reported yet. The L*, a*, b* values and the main carotenoids content of ‘Tainung No.2’ and one virus tolerant papaya line were used to quantify papaya pigments and chromaticity values at fruit maturity stages. The lycopene, β-carotene, and β-cryptocanthin content, measured by HPLC, were highly significantly correlated with the color readings. Regression of three main carotenoids content of ‘Tainung No.2’ papaya on a* value yielded the equations β-cryptoxanthin+ β-carotene +lycopene, μg．g-1 as followed: -0.0006 a* 4 + 0.0161 a* 3 - 0.0386 a* 2 + 0.2484 a* + 2.3905. The regression that color reading a* of the viral tolerant breeding papaya line to β-cryptoxanthin+ β-carotene +lycopene, ug．g-1 was as followed: 4.2309 (b*) - 42.239. The coefficient of determination of these 2 regression line were 90.3% and 92.4%, respectively. Estimation of the lycopene, β-carotene, and β-cryptocanthin contents of papaya can be achieved rapidly and reliably across wide range of papaya lines by using a portable colorimeter measurement. It will benefit the selection efficiency in the field work to quantify papaya color pigments.
‘Tainung No.2’ papaya is the most important variety with high yield potentiality, and rich of pigments. It supply the market demand throughout the year. 'Tainung No.2' is a hybrid; however, ‘Tainung No.2’ papaya fruit has various shapes, size, flesh color in the market. It possibly is due to parental genetic make-up, cultivation practices, and local conditions. We collected the different sources which have a common name of ‘Tainung No.2’ variety planted design by RCBD with two repetitions in the net-house under the same management. Significant difference of fruit weight, the total soluble solids, fruit pulp color, pigment contents, hue, lycopene content, vitamin A content were found among collections of diffeent locations. Oxygen radical absorbance capacity assay (ORAC) was also to quantify papaya fruit total antioxidant activity. Each gram papaya fruit pulp was 2.3~4.9 folds equal to 1 μmol Trolox.. The colormeter value of a* value measured by colorimeter and the total soluble solids of different ‘Tainung No.2’ was linear correlated. Regressing total soluble solids content of ‘Tainung No.2’ papaya on a* value yielded the regression equations as Brixo = 0.2604 (a*) + 2.7107 (R2= 0.514). Variety so-called ‘Tainung No.2’ under the same cultivation management practices has different genetic make-up, it also permitted to provide useful genetic variability to improve pigment contents in the future.

並列關鍵字

papaya ； color reading ； carotenoid ； correlation analysis

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