Chemical Characteristics of Tannins from Non-Astringent and Astringent Type Fruits of Japanese Persimmon (Diospyros kaki) with Particular Reference to Ultracentrifugal Behavior
Chemical Characteristics of Tannins from Non-Astringent and Astringent Type Fruits of Japanese Persimmon (Diospyros kaki) with Particular Reference to Ultracentrifugal Behavior
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日本柿 (Diospyros kaki) 非涩型和涩型果实中单宁的化学特性，特别是超离心行为
DOI：
10.2503/jjshs.53.121
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
J. Matsushima
中科院分区：
文献类型：
--
作者：
K. Yonemori;J. Matsushima
用连续扫描电子显微镜研究了柿果单宁的分析超离心纹影和对乙醛的反应性。1）为了研究纹影模式，用丙酮水溶液从两个品种中提取单宁，通过CPG-10 2000 A体积排阻色谱将其分离为两个组分（F-I和F-II）。在单宁浓度平衡后，将这些级分在40°C下孵育，并在预孵育（0天）、孵育1天和3天进行超离心。纹影图谱显示，两品种的F-I和F-II级分均含有3 ~ 4种单宁组分，且“平谷”各组分的沉降系数均大于“富玉”相应组分的沉降系数。此外，从'Hiratanenashi'的F-I馏分的组分在孵育过程中发生了显着变化或移位，两个快速组分（26 S和23 S）消失，一个较慢的组分（6S）出现。2）为了研究单宁对乙醛的反应性，比较了不同单宁浓度和pH条件下，"富玉“和"平谷梨”果汁在乙醛蒸汽中的凝固时间。当pH值在3.0 ~ 5.0之间时，单宁浓度越低，混凝时间越长。结果表明，"富裕“果汁中的单宁物质主要分布在低分子量范围内，其化学性质较”平田稔“果汁温和。
Schlieren pattern in analytical ultracentrifugation and reactivity to acetaldehyde of tannins of Japanese persimmon fruit (Diospros kaki) were investigated using cvs. ‘Fuyu’, pollination constant non-astringent (PCNA) type, and‘Hiratanenashi’, pollination variant astringent (PVA) type.1) To study the schlieren pattern, tannins extracted from both cultivars with aqueous acetone were separated into two fractions (F-I and F-II) by size exclusion chromatography on CPG-10 2000A. After the tannin concentrations were equalised, these fractions were incubated at 40°C and subjected to ultracentrifugation at pre-incubation (0 day), 1 and 3 days of incubation. The schlieren patterns revealed that F-I and F-II fractions from both cultivars contained three or four tannin components, and that the sedimentation coefficient of each component from‘Hiratanenashi’ was larger than the corresponding component from‘Fuyu’. Moreover, the components of the F-I fraction from‘Hiratanenashi’changed or shifted remarkably during incubation; two faster components (26S and 23S) disappeared and one slower component (6S) appeared. Conversely, the components of both fractions (F-I and F-II) from‘Fuyu’and F-II fraction from‘Hiratanenashi’were stable.2) To characterize the reactivity of tannins to acetaldehyde, coagulation times of the fruit juice bathed in acetaldehyde vapor were compared between‘Fuyu’and ‘Hiratanenashi’at different tannin concentrations and pHs. A longer time was needed for coagulation as the tannin concentration became lower and when the pH value was between 3.0 and 5.0. The fruit juice from‘Fuyu’coagulated more slowly than that from‘Hiratanenashi’.The present results suggest that tannin substances from‘Fuyu’distribute mainly in a lower molecular weight range and have a milder chemical property compared with those from‘Hiratanenashi’.