CAJ | 학술논문

用分光光度法在体外研究了不同pH条件下马铃薯'转心乌'块茎花色苷颜色呈现和降解速率的变化,以探讨马铃薯'转心乌,块茎颜色呈现的机理.结果显示:在pH 2.0时,该花色苷呈现最强烈的红色.随着pH从0增加到13.0,该花色苷在可见光区的最大吸收波长(λvis max)依次出现红移、蓝移,然后消失,在可见光区的最大吸收波长处的吸光值(Aλ,vis max)呈现为一条单峰曲线,峰值在pH 2.0处.当原始pH值被恢复到2.0后,如果原始pH小于或等于5.0,花色苷的红色均被恢复得更浓烈,λvis max不同程度地趋向537 nm,Aλ,vis max增加;如果原始pH大于或等于6.0,花色苷的红色根本不能被恢复,λvis max几乎不变,Aλ,vis max仍然维持低水平.在15℃、黑暗中,该花色苷在pH 0～5.0条件下均随时间推移而降解,在pH 2.0时的降解速度最慢;当pH小于或等于3.0时,该花色苷总体上降解缓慢,而且降解过程基本符合一级反应动力学.研究表明,'转心乌'块茎花色苷在可见光区的吸收光谱和在15℃、黑暗中的降解速度均具pH依赖性.
용분광광도법재체외연구료불동pH조건하마령서'전심오'괴경화색감안색정현화강해속솔적변화,이탐토마령서'전심오,괴경안색정현적궤리.결과현시:재pH 2.0시,해화색감정현최강렬적홍색.수착pH종0증가도13.0,해화색감재가견광구적최대흡수파장(λvis max)의차출현홍이、람이,연후소실,재가견광구적최대흡수파장처적흡광치(Aλ,vis max)정현위일조단봉곡선,봉치재pH 2.0처.당원시pH치피회복도2.0후,여과원시pH소우혹등우5.0,화색감적홍색균피회복득경농렬,λvis max불동정도지추향537 nm,Aλ,vis max증가;여과원시pH대우혹등우6.0,화색감적홍색근본불능피회복,λvis max궤호불변,Aλ,vis max잉연유지저수평.재15℃、흑암중,해화색감재pH 0～5.0조건하균수시간추이이강해,재pH 2.0시적강해속도최만;당pH소우혹등우3.0시,해화색감총체상강해완만,이차강해과정기본부합일급반응동역학.연구표명,'전심오'괴경화색감재가견광구적흡수광보화재15℃、흑암중적강해속도균구pH의뢰성.
In order to probe the mechanism of the stem tuber coloration of Solanum tuberosurn L. ' Zhuanx-inwu', we studied the changes of the coloration and degradation rate of the stem tuber anthocyanins of S. Tuberosurn 'Zhuanxinwu' under different Ph conditions in vitro with spectrophotometry. The results showed that:at Ph 2.0,the anthocyanins displayed the strongest red. Along with the increase of Ph values from 0 to 13.0,the maximal absorption wavelength in visible light (λvis max) of the anthocyanins expressed bathochromic shift and hypsochromic shift orderly, then disappeared, and the absorbance values at the max-imal absorption wavelength in visible light (Aλ,vis max) exhibited a single-peak curve, with the peak at Ph 2.0. After the primitive Ph values were restored to 2.0,if the primitive Ph was lower than or equal to 5.0,the red hues of the anthocyanins were all resumed to much stronger,the Aλvis max altered toward 537 nm in different degrees,and the Aλ,vis max inereased; If the primitive Ph was higher than or equal to 6.0,the red hues of the anthocyanins could not be resumed at all,the λvis max did not almost change,and the low Aλ,vis max also remained unchangeable. Being placed at 15℃ in darkness,the anthocyanins at the Ph values of 0～5.0 degraded totally along with time. The degradation rate at Ph 2.0 was the slowest,and when the Ph was lower than or equal to 3.0, the anthocyanins degraded slowly as a whole. In addition, the degradation cour-ses of the anthocyanins basically approximated first-order reaction kinetics. In a word, the research indica-ted that the visible light absorption spectra and degradation rates of the stem tuber anthocyanins of S. Tu-berosum L. 'Zhuanxinwu' at 15℃ in darkness are all Ph-dependent.