红心火龙果发酵液喷雾干燥工艺优化及红心火龙果籽油的研究

以红心火龙果发酵液作为研究对象,通过优化喷雾干燥工艺制备粉剂,最佳工艺条件为:20%麦芽糊精,进液量:10mL/min,进口温度为120℃,出口温度为65℃;得到的粉剂为紫红色粉末,益生菌含量达到108cfu/g以上,口感酸甜。将发酵后的火龙果籽进行提取,得到的火龙果籽油含有丰富的十六酸、亚油酸和油酸。     

Influence of drying conditions on colour,betacyanin content and antioxidant capacities in dried red-fleshed dragon fruit (Hylocereus polyrhizus)

In this study, drying of red-fleshed dragon fruit at different temperatures (40, 50, 60, 70 and 80 °C) and air velocities (1.0 and 1.5 m s⁻¹) was conducted under the specific humidity of 25 g H₂O kg⁻¹ dry air. The results showed that drying at higher temperatures resulted in shorter drying times. However, temperature and air velocity did not significantly affect the total betacyanin contents and antioxidant capacities in dried products. Seven betacyanins identified by LC-MS were betanin, isobetanin, phyllocactin, isophyllocactin, betanidin 5 –O-(6′O-3-hydroxybutyryl)-β-glucoside, isobetanidin 5 –O-(6′O-3-hydroxybutyryl)-β-glucoside and decarboxylated phyllocactin. In addition, the temperature increased the isomerisation of betacyanins. The most preferable condition for preserving the colour and betacyanin contents of red-fleshed dragon fruit was the drying at a temperature of 80 °C and air velocity of 1.5 m s⁻¹ since it could shorten the drying time and give a bright red colour to the dried product as well as it had no significant impact on the betacyanins.     

顶空固相微萃取- 气相色谱/质谱法分析霸王花挥发性成分

目的：探索分析霸王花挥发油化学成分的方法。方法：采用聚二甲基硅氧烷萃取头室温顶空微萃取20min、初始柱温60℃、程序升温至250℃、进样口温度250℃的气相色谱条件,EI 离子源、电子能量70eV 的质谱条件进行气相色谱/ 质谱法分析。结果表明：共鉴定出49 种化合物,主要挥发性成分及其含量为倍半萜及其含氧衍生物(27.78%)、脂肪族化合物(25.14%)、酯(14.40%)、2,6- 二叔丁基对甲酚(10.08%)和硅氧烷类化合物(6.27%)。结论：无溶剂的顶空萃取- 气相色谱/ 质谱联用技术可作为霸王花挥发性成分分析的有效方法。     

Betacyanins extraction from Hylocereus polyrhizus using alcohol/salt-based liquid biphasic partitioning system and antioxidant activity evaluation

Betacyanins have gained increasing interest as natural food dye because of their health-promoting effects. This study investigated the betacyanins extraction from peel and flesh of red–purple pitaya using ethanol/K₂HPO₄-based liquid biphasic partitioning system (LBPS) by optimised concentrations of ethanol, K₂HPO₄, NaCl and crude. Overall, the highest values of betacyanins concentration in alcohol-rich top phase (C_t), phase volume ratio (V_r) and partition coefficient (K) of betacyanins that represented an optimum betacyanins extraction from the peel (98.080%, 1.667 and 51.097, respectively) and flesh (96.256%, 2.167 and 25.764, respectively) were achieved. Lastly, conventional solvent extractions, colour characterisation and antioxidant activity evaluation were conducted.     

火龙果种仁脂肪酸和氨基酸的分析

分别用GC/MS分析仪和氨基酸自动分析仪分析了火龙果种仁的脂肪酸和氨基酸的组成成分。结果表明火龙果种仁的不饱和脂肪酸含量较高,为80.83%;火龙果种仁的必需氨基酸含量为24.38%。     

火龙果皮原花青素提取纯化及定性分析

采用大孔树脂对原花青素粗品进行分离纯化。比较了AB-8、DM130、ADS-17三种大孔树脂对原花青素的吸附和解吸能力,选择AB-8型大孔树脂为吸附树脂。对AB-8大孔树脂吸附解吸条件进行优化,探讨上样流速、解吸流速和解吸剂体积分数3 个因素对分离纯化效果的影响。结果表明：AB-8大孔树脂提纯工艺的最佳条件为上样流速2 mL/min、解吸流速1 mL/min、解吸剂体积分数50%。通过花青素反应与高效液相色谱-质谱对提取物进行定性分析,证实该提取物中含有的原花青素为儿茶素、表儿茶素和二聚体,且原花青素纯度为96.65%。     

火龙果花的营养成分分析

采用ICP-MS、分光光度法、化学分析法和重量法对火龙果全花的营养成分进行了分析,结果表明,每100 g火龙果花干制品中水分、蛋白质、粗纤维、粗脂肪、总糖、灰分的含量分别为:7.12、11.80、10.01、1.15、23.61、7.43 g;火龙果花中钾的含量相当高,为13 772.07 mg/kg;镁、钙和磷元素的含量丰富,分别达到:1 788.34、1 745.44、307.90 mg/kg;铁、锰、锌等必需微量元素也较丰富.同时与同种属植物霸王花及火龙果果实的含量作了比较.     

火龙果真空冷冻干燥的模拟分析和实验研究

为了准确预测冷冻干燥时间,本文基于传热传质理论,利用COMSOL软件对厚度为12 mm、半径为4 cm的红心火龙果片进行建模,模拟升华干燥阶段火龙果内部水蒸气流动耦合热质传递、火龙果温度分布特性、升华界面位移以及冰升华过程,预测升华周期,并通过实验验证模型的可靠性.结果表明:模拟值与实测值相吻合且误差较小,火龙果中心点...