Changes in elements,pectic substances and organic acids during development of boysenberry fruit

Changes in elements, pectic fractions, and organic acids during the development of boysenberries are described. Fruit were grouped into nine developmental stages on the basis of fresh weight and anthocyanin content. Stages 1–5 covered the earliest period of development (Stage 1 fresh weight=1.34 g), marked by fruit expansion and little accumulation of anthocyanin, whereas during Stages 6–9, when ripening occurred, fruit expansion ceased and anthocyanin content increased greatly. Most elements (except B and Na) fell into two very distinct groups. Over the course of development the content of Ca, Mn and Sr per fruit varied bimodally and decreased after the cessation of fruit growth, indicating a net efflux from the fruit. In contrast, K, Mg, Fe, Cu, Zn, P and S, which were all very significantly intercorrelated (P<0.01), increased approximately linearly and thus showed a net influx into the fruit. The decrease in Ca, Mn and Sr content per fruit coincided with a decrease in Ca pectate and total pectin, and a greatly increased proportion of cold water-soluble pectin. Three acids, citric, malic and succinic, were detectable, with citric acid predominant. The changing content of malic acid paralleled that of Ca. The observed patterns of change suggested an increasing phloem/xylem influx ratio during fruit enlargement, with a subsequent loss of binding capacity in the cell-wall, enabling remobilization of wall-bound elements. The results imply that the Ca level in the fruit is important in the ripening of bramble fruit.     

Polyacylated Anthocyanins in Bluish-Purple Petals of Chinese Bellflower,Platycodon grandiflorum

The bluish-purple petals of Chinese bellflower, Platycodon grandiflorum (kikyo in Japanese), contain platyconin (1) as the major anthocyanin. Platyconin (1) is a polyacylated anthocyanin with two caffeoyl residues at the 7-position, and its color is stable in a diluted, weakly acidic aqueous solutions. HPLC analysis of the fresh petal extract showed the presence of several minor pigments. Photo-diode array detection of minor pigments suggested that some of these were polyacylated anthocyanins. To establish the relationship between structure and stability of the acylated anthocyanins and to obtain information on their biosynthetic pathways, minor pigments were isolated from the petals, and their structures were determined by MS and NMR analyses. Four known (2–5) and three new anthocyanins (6–8) were identified, which contained a delphinidin chromophore, and four of these (5–8) were diacylated anthocyanins, in which the acyl-glucosyl-acyl-glucosyl chain was attached at the 7-O-position of the delphinidin chromophore. These diacylated anthocyanins exhibited a bluish-purple color at pH 6, which was stable for more than a week.     

花色苷改性及应用研究进展

花色苷是一类最常见并且分布最广的类黄酮化合物,以糖苷的形式存在于自然界中,是许多植物组织中最主要的水溶性色素,因其具有食用安全、抗氧化能力强、可预防各种慢性疾病等优点而应用广泛。但是由于其结构特点,花色苷的稳定性较差、生物利用率较低,此外,花色苷的强亲水性还限制了其在亲脂性基质中的应用。通过物理与化学等方法进行花色苷改性可以提高其亲脂性能以及在外界环境下的稳定性和抗氧化性,为使其具有脂溶性特征提供一种有效解决策略。本文对各种花色苷的改性方法及改性后产品的性能指标进行了综述和比较,为更深层次地展开对花色苷稳定性、脂溶性、生物活性等方面的研究及其在食品、药品等行业中的应用提供参考。     

壳聚糖/γ-聚谷氨酸负载黑米花色苷纳米粒的制备、表征及缓释性能

利用壳聚糖在pH驱动下与γ-聚谷氨酸通过离子凝聚法对黑米花色苷进行包埋,以改善黑米花色苷的稳定性和胃肠缓释能力。在单因素试验的基础上,以粒径、包封率作为优化指标进行响应面优化试验,获得黑米花色苷纳米粒的最佳制备条件为壳聚糖质量浓度0.8 mg/mL、聚谷氨酸-壳聚糖质量比7∶20、黑米提取物质量浓度1.98 mg/mL、pH 5.0和搅拌时间30 min,所得黑米花色苷纳米粒的包封率为50.90%,载药量为4.77%,粒径为（352.95±6.42）nm,PDI为（0.23±0.02）,Zeta电位为（29.56±1.09）mV,粒径较小、分散稳定。通过扫描电镜观察黑米花色苷纳米粒呈球形颗粒状;模拟胃肠缓释实验显示,与游离黑米花色苷相比,黑米花色苷纳米粒在胃、肠液中释放率分别减少52.65%和36.69%,这表明所制备的黑米花色苷纳米粒具有较好的缓释性能,具有较好的应用前景。     

基于氯化胆碱/乙酸的桑椹花青素高效提取工艺

为建立新型绿色高效的桑椹花青素提取工艺体系,该研究以桑椹为原料,以低共熔溶剂（Deep eutectic solvents,DESs）为提取剂,探讨了DESs种类、含水量、料液比以及提取温度和提取时间对花青素提取效率的影响,并在单因素试验基础上,采用响应面试验设计优化了提取工艺条件。结果显示：在提取剂为氯化胆碱/乙酸（1/3 n/n）-水（80/20 V/V）,料液比为1/10（g/mL）、提取温度为60 ℃,提取时间为40 min时,花青素的得率达6.35 mg/g,实验结果与响应面模型预测值接近,表明模型适用。此工艺提取桑椹花青素的效率远高于传统提取剂,这说明由适当比例氢键供体和受体所构成的DESs与目标产物之间强烈的氢键作用更有助于花青素的浸出和溶解。本研究结果为绿色可设计的DES溶剂用于天然产物的高效制备提供了借鉴。     

香格里拉海拔高度对‘赤霞珠’葡萄果实花色苷的影响

利用高效液相色谱(HPLC)测定香格里拉不同海拔高度‘赤霞珠’果实中各发育阶段主要花色苷成分变化。结果表明,在‘赤霞珠’果实中共检测到10余种花色苷衍生物,主要有矢车菊色素、飞燕草色素、芍药色素、矮牵牛色素和锦葵色素5种。香格里拉地区‘赤霞珠’葡萄花色苷含量在转色初期随海拔升高而增加,尤其在西当试验点较为明显,因为高海拔地区有着较强的光照和辐射,温度较低,有利于花色苷合成。同时表明,在转色期间低海拔试验点的葡萄花色苷含量较高,在成熟期为高海拔试验点花色苷含量较高,影响花色苷合成的因素错综复杂,各种因素之间有交互作用,需进一步研究。     

脚板薯花青素提取及其纯化技术研究

对脚板薯花青素提取及其纯化工艺进行研究,0.5%硫酸溶液作浸提剂,并使其pH小于或等于4.0,在60℃的温度条件下恒温加热60min,一般物料配比掌握在1∶10。实验结果表明,脚板薯是良好的花青素材料来源。     

短梗五加果色素提取条件的研究

研究以短梗五加果为试验材料,研究表明:短梗五加果色素属于水溶性花青素色素,酸性条件下呈红色并在525nm有特征吸收峰。单因素试验研究表明:温度、乙醇浓度、pH值对色素浸提有显著的影响;果胶酶、超声波、微波处理能够提高色素浸提效果,但效果不显著。正交试验结果表明:最佳的提取条件是温度80℃、95%的乙醇溶剂、pH值为2.0,影响浸提因素次序为pH值>乙醇浓度>温度。     

葡萄籽原花青素抗氧化作用的研究

采用亚油酸体系、脂质体体系、DPPH.及O2-.研究葡萄籽原花青素提取物的抗氧化活性,结果表明,葡萄籽原花青素具有很强的抗氧化和自由基清除能力,在亚油酸及脂质体体系中,原花青素的抗氧化活性高于VC和VE,并与VC、VE具有协同增效作用,随着浓度的增加,其抗氧化能力可以与合成抗氧化剂BHT相近;原花青素对DPPH.自由基的清除能力优于VC、VE及BHT,半抑制浓度分别为:原花青素1.8μg/mL、VC 2.5μg/mL、VE 6.3μg/mL、BHT 3.5μg/mL。对O2-.的清除能力优于VE而与VC相近,半抑制浓度分别为原花青素15.4μg/mL、VC 14.5μg/mL、VE 177μg/mL。     

酶法生产草莓汁的研究

研究了直接榨汁、解冻后榨汁、纤维素酶酶解、果胶酶酶解四种方法对生产草莓汁品质的影响,结果表明,果胶酶酶解生产草莓汁效果最佳。通过正交实验研究了酶加入量、酶解温度、酶解时间对草莓汁出汁率、花色苷及Vc的影响。结果表明,果胶酶制取草莓汁的最佳工艺是:酶加入量0.005%、酶解时间1h、酶解温度50℃。此条件下生产的草莓汁色泽鲜艳、营养丰富,而且美味可口。