两个八仙花品种花色苷的提取、鉴定和理化稳定性

Extraction,identification and physical-chemical stability of anthocyanins from two Hydrangea varieties

关键词:  八仙花, 花色苷, 超声提取, 鉴定, 理化稳定性

Key words:  Hydrangea macrophylla, anthocyanins, ultrasonic extraction, identification, physical-chemical stability

摘要:

为优化八仙花花色苷提取条件,探究具有不同花色可调性的八仙花花色苷组分和理化稳定性差异,初步解释八仙花花色可调性存在差异的原因,该文以花色不可调的‘蒂亚娜(Tijana)'和花色可调的‘拉维布兰(Ravi Brent)'八仙花(Hydrangea macrophylla)为材料,通过L₉(3³)正交试验确定超声波法提取花色苷的最优条件,利用UPLC-Q-TOF-MS法进行花色苷组分的鉴定,分析离体条件下温度、光照、金属离子和糖类对八仙花花色苷理化稳定性的影响。结果表明:(1)花色苷提取的最优条件是‘蒂亚娜'和‘拉维布兰'的乙醇浓度分别为70%和80%,料液比均为1:20,提取时间均为20 min。(2)二者的主要花色苷组分均为飞燕草素-3-O-葡萄糖苷。(3)八仙花花色苷在温度≤ 70 ℃暗处保存效果更好。(4)花色不可调的‘蒂亚娜'八仙花花色苷对光照、糖类和大多金属离子更稳定; 只有花色可调的‘拉维布兰'八仙花花色苷加入中低浓度(10～30 mmol·L^-1)Al³⁺ 后由粉色变为蓝色且稳定性提高,而 ‘蒂亚娜'无此颜色变化,表明八仙花花色可调性的差异与其理化稳定性有关。该研究结果为八仙花花色苷提取、保存、花色改良以及干燥花护色等提供了理论依据。

Abstract:

To explain the reason for different flower color adjustabilities of Hydrangea macrophylla, non-adjustable color ‘Tijana' and adjustable color ‘Ravi Brent' of Hydrangea macrophylla were used as experimental materials. The extraction conditions were optimized and the components of H. macrophylla anthocyanins were measured. Their physical-chemical stabilities were also explored, aiming to explore the mechanism of flower color adjustability. The optimal extraction conditions of Hydrangea anthocyanins by the ultrasonic method were determined through L₉(3³)orthogonal experiments. The anthocyanin components were separated and identified by UPLC-Q-TOF-MS. And the effects of temperature, light, metal ions and sugars on the physical-chemical stabilities of H. macrophylla anthocyanins were also explored in vitro conditions. The results were as follows:(1)The optimal conditions for extraction of H. macrophylla anthocyanins were that the ethanol concentration for ‘Tijana' and ‘Ravi Brent' were 70% and 80% respectively; the ratio of plant material to extraction solution was both 1:20; and the extraction time was both 20 m.(2)The main anthocyanin component of the two varieties was both Delphinidin 3-O-glucoside.(3)H. macrophylla anthocyanins were more stable when stored below 70 ℃ and in the dark.(4)Both Cu²⁺ and Al³⁺ change the color of the anthocyanin solution, and Cu²⁺ specifically improved the stability of the anthocyanin of ‘Tijana'. 10-90 mmol·L^-1 Ca²⁺, Al³⁺ and 90 mmol·L^-1 Mg²⁺ had significant effects on the stability of anthocyanin of both varieties. Glucose, maltose, sucrose, galactose and 8%-10% concentration of rhamnose increased the stability of the non-adjustable color ‘Tijana' Hydrangea macrophlla anthocyanins. While 4%-10% concentration of rhamnose promoted the stability of adjustable color ‘Ravi Brent' Hydrangea macrophylla anthocyanins. The non-adjustable color ‘Tijana' of H. macrophylla anthocyanins were more stable to light, sugars and most metal ions, compared with the adjustable color ‘Ravi Brent'. Only the anthocyanins of the adjustable color ‘Ravi Brent' of H. macrophylla turned from pink to blue, and its stability increased after adding low medium concentration(10-30 mmol·L^-1)of Al³⁺. However, the non-adjustable color ‘Tijana' of H. macrophylla did not have this kind of color change, indicating that the difference in color adjustability of H. flowers is related to its physical-chemical stability. These results provide the theoretical reference for the extraction and observation of H. macrophlla anthocyanins, flower color improvement and dry flower color protection.