壳聚糖澄清玫瑰茄提取液工艺的研究

研究了壳聚糖对玫瑰茄提取液的澄清方法，确定了玫瑰茄提取液的澄清方式为：壳聚糖添加量0．125g/L，常温澄清4h，离心机高速离心，再经过硅藻土过滤、最后经过qb0．45μm微滤，可得到k为77、6％，混浊度0、12NTU的玫瑰茄提取液。     

食用玫瑰茄红色素的稳定性研究

以玫瑰茄为原料,采用乙醇提取法,同时对玫瑰茄天然红色素的稳定性进行了较为系统的研究,试验表明:色素对光、热、氧化剂的稳定性差;色素对金属离子Na+,Mg2+表现出较好的稳定性;食用酸的存在使色素稳定性增强.     

玛咖水提物抗小鼠前列腺增生作用

探讨了玛咖水提物抗前列腺增生的药效物质及其作用机理。将50只雄性ICR小鼠随机分为空白组、模型组、阳性药组,玛咖组(60 mg/kg,含苄基芥子油苷1.44 mg/kg)及苄基芥子油苷组(1.44 mg/kg)。除空白组外,其他组连续30 d皮下注射丙酸睾酮(5.0 mg/kg),制造小鼠前列腺增生模型,观察各组小鼠前列腺湿重、前列腺指数;血清中睾酮(T)、雌二醇(E2)、T/E2水平和前列腺酸性磷酸酶的影响及镜下病理学改变。结果显示,与模型组相比,玛咖组和苄基芥子油苷组小鼠前列腺湿重及前列腺指数显著降低(P0.01),血清T、DHT含量和T/E2比值明显降低(P0.05或P0.01),光镜下见前列腺增生程度大为减轻,增生的腺上皮乳头减少或消失,玛咖组的结果与苄基芥子油苷组相似。结果表明,玛咖水提物和苄基芥子油能显著抑制小鼠前列腺增生;苄基芥子油苷是玛咖水提取物抗前列腺增生主要的活性物质。     

食用玫瑰茄红色素的稳定性研究

研究了玫瑰茄红色素在不同pH值、温度及光照条件下的稳定性,及金属离子和食品添加剂对玫瑰茄红色素稳定性的影响,并对该色素的氧化还原特性进行了探讨。结果表明玫瑰茄红色素在pH2.98～3.46最稳定,耐酸性强,耐碱性差,耐氧化性和耐还原性都差。Na     

玫瑰茄提取物多酚含量与抗氧化作用研究

研究玫瑰茄的体外抗氧化活性。采用不同极性的有机溶剂萃取玫瑰茄40%乙醇提取物(粗提物),得到石油醚萃取物、氯仿萃取物、乙酸乙酯萃取物、正丁醇萃取物,然后采用Folin-Ciocalteu比色法测定粗提物以及各萃取物的多酚含量,同时应用DPPH法、试剂盒法、ABTS法分别测定粗提物和各萃取物的DPPH自由基清除能力、还原Fe3+能力以及ABTS自由基抑制能力。DPPH法、试剂盒法、ABTS法测定各提取物抗氧化能力的结果为粗提物>正丁醇萃取物>乙酸乙酯萃取物>氯仿萃取物>石油醚萃取物。玫瑰茄提取物具有较高的多酚含量和较强的抗氧化能力;玫瑰茄提取物的多酚含量与抗氧化能力之间存在较好的相关性。     

桑叶水提物预防小鼠高脂血症的作用研究

目的探讨桑叶水提取物(mulberry leaf water extract,MWE)的降血脂功效,为桑叶保健品降血脂的开发利用提供依据。方法在饲喂高脂饲料的同时,给予小鼠不同剂量的桑叶水提取物,28 d后摘眼球取血,测定不同试验组小鼠血清血脂水平、载脂蛋白A1(Apo A1)和载脂蛋白B(Apo B)含量、小鼠肝脏中3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR)、胆固醇-7α-羟化酶(CYP7A1)和卵磷脂胆固醇酰基转移酶(LCAT)活性和总胆汁酸(total bile acid,TBA)含量以及粪便含水率和TBA含量。结果与高脂组小鼠相比,MWE可降低高脂饮食小鼠肝脏系数及脂肪系数,并降低高脂饮食小鼠血脂水平,使肝脏HMG-COA和LCAT活性降低,提高CYP7A1活性,并抑制肝脏胆汁酸的积累,促进胆汁酸的排出。结论 MWE对高脂小鼠具有显著的降血脂功效,可有效减少脂肪积累,促进胆固醇代谢从而预防动脉硬化的发生。     

苦瓜水提物抑菌作用的初步探讨

测定分析了苦瓜水提物对十种常见食品污染微生物的抑菌活性。结果表明,苦瓜水提物对金黄色葡萄球菌、沙门氏菌、大肠杆菌、枯草杆菌等受试细菌具有良好的抑制作用,尤其对金黄色葡萄球菌、沙门氏菌等致病菌的抑制效果显著;苦瓜水提物对受试霉菌米曲霉、黑曲霉、桔青霉以及受试酵母啤酒酵母、粘红酵母、假丝酵母的抑制作用较弱。      

玫瑰茄红色素的结构定性研究

对玫瑰茄红色素进行了一系列定性实验,欲对其结构进行初步鉴定。结果表明:玫瑰茄红色素属于花青甙类色素,有邻二酚羟基或邻三酚羟基,含有葡萄糖和木糖两种糖苷。其主体结构是失车菊素和飞燕草素。     

玫瑰茄黄酒的工艺研究

以糯米和玫瑰茄浸提液为原料,酿制玫瑰茄糯米黄酒。通过单因素和正交试验优化玫瑰茄黄酒糖化和发酵的工艺条件。结果表明:最佳糖化工艺条件为糖化时间21 h、麦曲添加量12 g、糖化温度30℃;最佳发酵工艺条件为发酵时间72 h、发酵温度25℃、2%玫瑰茄浸提液添加量60 mL、酒曲添加量2.5%。在该条件下玫瑰茄黄酒的酒精度为13.8%vol,还原糖含量为0.256 mg/mL,pH 3.42。     

关于玫瑰茄饮料的试验研究

本文论述了以玫瑰茄花萼为原料加工而成的纯天然营养保健饮料的生产工艺方法配方设计和产品性能。成份分析测定及医学临床应用等研究表明，玫瑰茄花萼营养丰富，并具有营养保健作用，提取浸汁后的残花，还可以制作玫瑰茄酱。     

玫瑰茄花色苷的纯化及其热降解稳定性

本实验以玫瑰茄花色苷为原料,研究了花色苷纯化的条件,以及添加不同稳定剂下花色苷溶液的热降解稳定性。结果表明:纯化花色苷的优化条件为上样浓度为600 mg/L,平衡3 h,上样体积为183 mL;洗脱剂为60%乙醇,洗脱流速为1 mL/min。纯化后的玫瑰茄花色苷冻干粉末,其色价为43.10±2.17,回收率为83.62%±5.72%,花色苷含量为216.50±1.83mg/g。添加1.0%海藻酸钠、羧甲基纤维素(Carboxymethylcellulose,CMC)和β-环糊精的三组玫瑰茄花色苷溶液在80、90和100℃三个温度下的降解均符合一级动力学方程,降解速率常数均随着温度的升高而增大,半衰期随着温度的升高而减小。β-环糊精具有很好的延缓花色苷降解的潜力,随着β-环糊精浓度的增加,花色苷的降解速率越来越小。80℃下加热150 min后,花色苷溶液中a*值减小,b*值增加,β-环糊精的浓度增加有利于维持花色苷的红度,其中1.5%β-环糊精组的护色效果最佳。     

大孔树脂吸附法提取玫瑰茄红色素

对使用大孔树脂吸附提取玫瑰茄红色素的条件和方法进行研究。通过7 种树脂对玫瑰茄红色素的吸附及不同洗脱剂的解吸比较表明：HPD-100 树脂对该色素有较好的吸附性能,用90% 的乙醇洗脱,使用20 次后其吸附性能无明显减弱,可循环使用。     

玫瑰茄栽培及其在食品工业应用研究进展

玫瑰茄是一种热带、亚热带经济作物,天然的药食两用营养保健植物。玫瑰茄含有的木槿酸、花青素、还原糖等,对人体具有重要的保健作用,花萼富含天然色素,又是色、香、味俱佳的食用材料。该文阐述了玫瑰茄的栽培技术及玫瑰茄花萼的有关产量,并对其各器官的化学成份进行了分类总结,综述了玫瑰茄在食品工业开发应用的最新研究进展,以期为更好地栽培利用玫瑰茄提供技术参考。     

Hibiscus sabdariffa L. extracts inhibit the mutagenicity in microsuspension assay and the proliferation of HeLa cells

ABSTRACT:  Hibiscus sabdariffa L. is used as a refreshing beverage and as a traditional medicine. The objective of this study was to determine the in vitro effect of phenolic compounds present in aqueous, ethyl acetate, and chloroform extracts of H. sabdariffa against mutagenicity of 1-nitropyrene (1-NP), and also the antiproliferative effect of these extracts. Inhibition of cell proliferation and DNA fragmentation were tested on transformed human HeLa cells. The hot aqueous extract (HAE) contained 22.27 ± 2.52 mg of protocatechuic acid (PCA) per gram of lyophilized dried extract, and was not statistically different from the cold aqueous or chloroform extracts; the ethyl acetate extract produced the least amount of PCA. The H. sabdariffa extracts inhibited mutagenicity of 1-NP in a dose-response manner. The inhibition rate on HeLa cells of HAE was also dose-dependent. The HAE did not induce DNA fragmentation. The results suggest that H. sabdariffa L. extracts have antimutagenic activity against 1-NP and decrease the proliferation of HeLa cells, probably due to phenolic acid composition.     

Consumption of Hibiscus sabdariffa L. aqueous extract and its impact on systemic antioxidant potential in healthy subjects

BACKGROUND: To evaluate health benefits attributed to Hibiscus sabdariffa L. a randomized, open‐label, two‐way crossover study was undertaken to compare the impact of an aqueous H. sabdariffa L. extract (HSE) on the systemic antioxidant potential (AOP; assayed by ferric reducing antioxidant power (FRAP)) with a reference treatment (water) in eight healthy volunteers. The biokinetic variables were the areas under the curve (AUC) of plasma FRAP, ascorbic acid and urate that are above the pre‐dose concentration, and the amounts excreted into urine within 24 h (Ae_0–24) of antioxidants as assayed by FRAP, ascorbic acid, uric acid, malondialdehyde (biomarker for oxidative stress), and hippuric acid (metabolite and potential biomarker for total polyphenol intake). RESULTS: HSE caused significantly higher plasma AUC of FRAP, an increase in Ae_0–24 of FRAP, ascorbic acid and hippuric acid, whereas malondialdehyde excretion was reduced. Furthermore, the main hibiscus anthocyanins as well as one glucuronide conjugate could be quantified in the volunteers' urine (0.02% of the administered dose). CONCLUSION: The aqueous HSE investigated in this study enhanced the systemic AOP and reduced the oxidative stress in humans. Furthermore, the increased urinary hippuric acid excretion after HSE consumption indicates a high biotransformation of the ingested HSE polyphenols, most likely caused by the colonic microbiota. Copyright © 2012 Society of Chemical Industry     

Aqueous extract of Hibiscus sabdariffa L. decelerates acetaminophen‐induced acute liver damage by reducing cell death and oxidative stress in mouse experimental models

BACKGROUND: Acetaminophen (AAP)‐induced oxidative stress can cause cell death to induce liver damage. The antioxidant effect of Hibiscus sabdariffa L. (HS) was shown in previous studies. In this study the effect of HS extract (HSE) on AAP‐induced liver injury in BALB/c mice was investigated. RESULTS: In vivo, BALB/c mice were fed orally with 200, 400 or 600 mg kg⁻¹ HSE for 2 weeks and then injected with 1000 mg kg⁻¹ AAP. Pretreatment with HSE decreased lipid peroxidation and increased catalase activity and glutathione level. It also decreased AAP‐induced liver injury, accompanied by decreased expression of pJNK, Bax and tBid in the liver. Additionally, HSE protected BALB/c normal liver cells from AAP‐induced damage in vitro. CONCLUSION: It has been demonstrated that HSE can protect the mouse liver from AAP‐induced injury and that the protective mechanism might involve decreasing oxidative stress and reducing cell death. Copyright © 2009 Society of Chemical Industry     

Release kinetics of antioxidant compounds from Hibiscus sabdariffa L. encapsulated in gelatin beads and coated with sodium alginate

Gelatin beads containing a concentrated extract of Roselle (Hibiscus sabdariffa L.) calyx rich in polyphenolic compounds were coated with sodium alginate and ionotropically gelled using CaCl₂. Single‐coated beads and double‐coated beads were obtained by this technique, and the release pattern of the loaded extract was evaluated. As a result, release pattern of these compounds fits properly to a first–order Weibull distribution equation. The release rate constant decreased linearly with the number of alginate coats and with the increase in immersion time in CaCl₂ and the Lag period increased significantly with the number of alginate coats. The release of H. sabdariffa's polyphenols can be well controlled manipulating the number of alginate coats and the immersion time in a CaCl₂ solution, allowing not only to control the gastrointestinal segment where they could be released but also to control the release rate with the certainty that the initial concentration will be completely released showing a highly significant antioxidant activity as well.