Study on Processing of Clear Banana Juice Using Hot Water Extraction Method

In this study, the effects of hot water temperature on clarity, total soluble solids, polyphenol oxidase （PPO） and color of banana juice during hot water ex-traction were discussed based on the theory in which heat treatment might induce the pectin and protein in banana pulp to form insoluble products. The results showed the hot water temperature had a significant effect on the formation of insol-uble polymers in banana pulp from pectin and protein. In 75 ℃ water, the pectin and protein in banana pulp were most inclined to form insoluble products. Under this condition, the clarity of banana juice was also highest. The light transmittance at 660 nm was close to 90%. In the banana juice, extracted by 75 ℃ water, the pectin and protein contents were lowest, and they were lower than 7.3 mg/100 ml and 12.9 mg/100 ml respectively. The 75 ℃ water could not inactivate completely the pectin in banana pulp due to its high heat resistance, Therefore, 0.05% L-cys-teine or ascorbic acid needed to be added into banana pulp to inhibit the browning of juice induced by residual PPO.

Changes in Soil Hot-Water Extractable C,N and P Fractions During Vegetative Restoration in Zhifanggou Watershed on the Loess Plateau

The study was conducted in Zhifanggou Watershed,Shaanxi Province,China,to evaluate the effect of different vegetation types on hot-water extractable C,N and P fractions,with the aim to determine whether hot-water extractable fractions could be used as indicators of soil quality change in Loess Plateau.The six vegetation types established in 1975 were（i） Robinia pseudoacacia L.,（ii） Caragana korshinkii Kom.,（iii） Pinus tabulaeformis Carr.,（iv） P.tabulaeformis-Amorpha fruticosa L.,（v） R.pseudoacacia-A.fruticosa,and（vi） grassland.A cropped hillslope plot and a Platycladus orientalis L.native forest plot were used as references.The results indicated that the conversion of native forest to cropland resulted in a significant decline in the hot-water extractable C,N and P fractions.Hot-water extractable C,N,and P increased when cultivated land was revegetated,but after 30 years the amount of hot-water extractable C,N,and P in revegetated fields was still much lower compared to native forest.Hot-water extractable fractions increased more under mixed-forest than under pure-forest stands.Furthermore,there was a significant correlation between the hot-water extractable fractions and soil chemical and microbiological properties.The results showed that hot-water extractable fractions could be used as indicators of soil quality change on the Loess Plateau.

In Vitro Antioxidant Activity of Hot Water Extracts from 7 Different Sources of Ganoderma Lucidum

[Objectives] To study the in vitro antioxidant activity of hot water extracts from 7 different sources of Ganoderma lucidum mushroom.[Methods] The in vitro antioxidant activity of hot water extracts from 7 different sources of G. lucidum was studied from total reducing capacity,scavenging of hydroxyl free radical( ·OH),superoxide anion( O_2^(2-)·),and DPPH free radical.[Results]Under the same concentration,hot water extracts wild G. lucidum in Maoer Mountain showed the strongest reducing capacity with the absorbency being 2. 48,the highest scavenging capacity of hydroxyl free radical( · OH) with the scavenging rate being 99. 46%,and the strongest scavenging ability of DPPH free radical with its scavenging rate being 96. 62%. The ability of scavenging superoxide anion free radical( O_2^(2-)·) ranked the third.[Conclusions]The hot water extracts from Maoer Mountain wild G. lucidum showed the highest antioxidant ability in three aspects,indicating that Maoer Mountain wild G. lucidum has high development potential.

Effects of hot-water extract of <i>Paecilomyces hepiali</i>on hypertension parameters in Spontaneously Hypertensive Rats

In this study, effects of hot water extract of Paecilomyces hepiali mycelia on hypertension parameters in spontaneously hypertensive rats (SHR) were investigated. The tested parameters included blood pressure, blood and urine biochemical composition, renin and angiotensin II levels in the blood. Prior to these tests, the extract was examined for toxicity. The fungus was cultivated in a solid medium composed of 40 g brown rice, 0.32 g glucose, 0.65 g sucrose, 2 g peptone and 65 ml corn steep liquor. No abnormality or harmful effects were observed in the toxicity test. Administration of a continuous-dose, once daily, to SHR for 27 weeks (from 13 weeks of age) decreased the systolic blood pressure (SBP) significantly. Levels of blood urea nitrogen, β-lipoprotein lipid peroxides and low density lipoprotein were significantly lower in the treated groups when compared to the control group. Urinary protein was significantly reduced in the middle and high dose groups. In comparison with the control group (0 mg/kg/10ml/day), significantly higher values were obtained for total cholesterol in groups that were given middle (170 mg/kg/10ml/day) and high (250 mg/kg/10ml/day) dosages. In all dosages (low, middle and high) the values for triglyceride were significantly higher than value found in the control group. In terms of angiotensin II levels, the value in the control group was markedly higher than values in the other groups. The results suggest that oral administration of hot water extract of P. hepiali mycelia has ability to control hypertension in rats.

Profile distribution and seasonal dynamics of water-extractable carbohydrate in soils under mixed broad-leaved Korean pine forest on Changbai Mountain

Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate is thought related to soil carbon sequestration due to the asso- ciation with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spatial dis- tribution, and seasonal dynamics of cool and hot-water extractable car- bohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate （CWECH） in three soil layers （0-5, 5-10, 10-20 cm） ranged from 4.1 to 193.3 g.kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate （HWECH） concentrations in three soil layers ranged from 121.4 to 2026.2 g.kgq dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The car- bohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV2s0 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon.

The Influence of Drying Temperature and Extraction Methods on a-Mangostin in Mangosteen Pericarp

The effects of drying temperature and extraction methods on α-mangostin content in mangosteen pericarp （Garcinia mangostana L.） powder were investigated. In the first part of experiment suitable drying temperature for retention α-mangostin content was determined. Three levels of drying temperatures （55, 65 and 75 ℃） were used in this study. The drying rates were increased with drying temperature. Room temperature extraction method was performed to investigate the effect of drying temperature on retention α-mangostin content in mangosteen pericarp. The α-mangostin content extracted at three different drying temperatures （55, 65 and 75 ℃） was 35.98 ± 0.49%, 40.32 ± 0.24%, and 37.79±0.34% w/w, respectively. The results showed that the suitable temperature for drying mangosteen pericarp was 65 ℃ that gave the highest of α-mangostin content. The second part of experiment was the comparison between extraction methods, such as shaking water bath extraction （SWE）, soxhlet extraction （SE） and microwave-assisted extraction （MAE）. The results show that MAE gave the highest extraction rate and α-mangostin content as compare to SWE and SE. The α-mangostin content extraction from SWE, SE and MAE are 45.83 ± 0.02, 34.82± 0.17 and 49.79 ± 0.15% w/w of crude extract, respectively.

Ultrasound-assisted Low Density Solvent Based Dispersive Liquid-liquid Microextraction for Determination of Phthalate Esters in Bottled Water Samples

A technique of ultrasound-assisted low density solvent based dispersive liquid-liquid microextraction was developed for the determination of four phthalate esters, including dimethyl phthalate（DMP）, diethyl phthalate（DEP）, di-n-butyl phthalate（DnBP） and di（2-ethylhexyl） phthalate（DEHP） in bottled water samples. A low density solvent, toluene, was selected as extraction solvent. In the extraction process, a mixture of 15 μL of toluene（extraction solvent） and 100 μL of methanol（disperser solvent） was rapidly injected into 1.0 mL of water samples. A cloudy solution was formed after ultrasounded for 5 min, and then centrifuged at 5000 r/min for 5 min. The enriched analytes in the floa- ting phase were determined by means of gas chromatograph. Under the optimum conditions, the enrichment factors were found to be in a range of 29--67, and the recoveries were ranged from 81.2% to 103.9%. The limits of the detection were in a range of 3.8--5.6 μg/L. The proposed method was applied to the extraction and determination of phthalate esters in bottled water samples, and the concentrations of phthalate esters found in the water samples were below the allowable levels.

微波处理对刺槐豆胶多糖结构特征的影响

采用微波辅助法(microwave-assisted extraction,MAE)和热水浸提法(hot water extraction,HWE)处理刺槐豆胶,并对得到的刺槐豆胶多糖(locust bean gum polysaccharide,LBGP)进行分子量及分子量分布、糖链构象、单糖组成、糖苷键类型等一系列表征进行分析。通过比较发现,MAE-LBGP的分子量(2.744〜3.777×10^(6) g/mol)显著高于HWE-LBGP(1.222〜1.593×10^(6) g/mol),且具有更宽的分子量分布,不均一性的增强使得糖链呈现出更加多样化及更为紧密的构象特征,而HWE-LBGP的构象则表现得相对单一和松散。经由两种提取方式得到的LBGP具有相同的单糖组成种类(甘露糖和半乳糖)和糖苷键类型(1→4与1→6位连接键)。以上结果归因于在微波效应的作用下,溶剂的极化作用增强,提取能力增加,并通过增强溶剂的传质能力,获得了高分子量和更宽分布的多糖所致。本研究为微波技术在多糖提取应用方面提供了支持和帮助。

饲用桑叶多糖提取工艺优化及其体外抗菌活性研究

试验以饲用桑叶为原料,采用热水浸提法提取多糖。以提高桑叶中多糖提取率为优化目标,采用单因素试验分别研究液料比、提取温度和提取时间对多糖提取率的影响,利用正交分析法优化桑叶多糖提取工艺参数组合,并利用牛津杯法检测桑叶多糖的体外抑菌活性。结果显示,各因素对桑叶多糖提取率的影响排序为提取温度>液料比>提取时间,最优生产工艺参数组合为液料比30 L/g、提取温度90℃、提取时间3 h。在最优工艺条件下,桑叶多糖提取率为6.69%。桑叶多糖对金黄色葡萄球菌和大肠杆菌具有明显的抑制作用,抑菌圈直径分别为9.22、11.74 mm,最低抑菌浓度均为2.0 g/L。研究表明,热水浸提法提取的桑叶多糖可作为功能性饲料添加剂应用于动物养殖。

3种木质纤维原料热水抽出物抗氧化性的研究

本研究对青皮竹、桉木和杨木3种木质纤维原料进行热水抽提处理(95℃,1 h,浆浓5%),比较了不同热水抽出物的抗氧化性差异,通过紫外可见分光光度计、凝胶渗透色谱仪、热解-气相色谱/质谱联用仪和傅里叶变换红外光谱仪等分析设备和方法,研究了不同木质纤维原料热水抽出物的抗氧化性及化学结构差异。结果表明,桉木热水抽出物的抗氧化性最强(半抑制浓度为51.80 mg/L),优于商业抗氧化剂2,6-二叔丁基-4-甲基苯酚(半抑制浓度为87.99 mg/L);不同木质纤维原料热水抽出物的抗氧化性与其酚羟基含量和共轭结构相关;热水抽出物的主要组分为木质素、多糖等有机大分子合成反应过程的中间产物。

连翘多糖提取工艺优化及抗氧化和抑菌活性研究

以连翘果实为原料,采用超声波辅助水提醇沉法提取连翘粗多糖,以连翘粗多糖提取率为考察指标,在单因素试验的基础上,采用正交试验对连翘粗多糖提取工艺进行优化,进而采用DPPH法和ABTS法考察连翘多糖体外抗氧化活性,抑菌圈法考察连翘多糖对大肠埃希菌等食物腐败菌的抑菌活性。结果表明,连翘果实多糖的最佳提取工艺为:料液比1:20(g:mL),提取温度70℃,超声功率70 W,提取时间50 min。在此条件下,连翘果实多糖提取率为1.98%。连翘粗多糖对金黄色葡萄球菌和大肠埃希菌均有良好的生长抑制作用,且对金黄色葡萄球菌的抑制作用优于大肠埃希菌。当连翘粗多糖质量浓度为2.5 mg/mL时,大肠埃希菌的抑菌圈平均直径为10.46 mm,金黄色葡萄球菌抑菌圈平均直径为11.73 mm。连翘多糖对DPPH·和ABTS·有较好的清除能力,并呈现良好的质量浓度-效应关系。连翘多糖不但对食品腐败菌有一定的抑菌活性,还具有良好的体外抗氧化活性。可见,连翘粗多糖具有开发成食品防腐保鲜剂的潜能。

热水浴提取结合UPLC-MS/MS同时测定枸杞中氯酸盐和高氯酸盐

该研究建立了热水浴提取-分散固相萃取(DSPE)净化-超高效液相色谱-串联质谱(UPLC-MS/MS)测定枸杞干果、鲜果中氯酸盐和高氯酸盐含量的方法。试样用7 m L超纯水在60℃水浴中振荡提取30 min后,加入13 m L甲醇涡旋5 min,离心后上清液用C18和石墨化碳黑(GCB)组合分散固相萃取净化,净化液在电喷雾负离子源和多反应监测(MRM)模式下测定,基质外标法定量。结果表明,枸杞干果、鲜果中氯酸盐和高氯酸盐均分别在1.0~100.0 ng/mL、0.5~100.0 ng/mL范围内线性关系良好,相关系数R2分别为0.998 9和0.999 2及0.998 4和0.999 0。氯酸盐检出限(LOD)为1.0μg/kg、定量限(LOQ)为10.0μg/kg;高氯酸盐LOD为0.5μg/kg、LOQ为5.0μg/kg。干果中氯酸盐和高氯酸盐平均加标回收率分别为89.9%~93.4%和76.8%~93.6%,相对标准偏差(RSD)分别小于11.0%和12.0%;鲜果中氯酸盐和高氯酸盐平均加标回收率分别为73.8%~94.9%和61.2%~90.5%,RSD分别小于11.0%和17.0%。

响应面优化黄姜花根多糖提取工艺及其抗氧化活性分析

试验旨在探究黄姜花根多糖的最佳提取工艺及其体外抗氧化活性,以黄姜花根为原料,探究液料比、提取温度、提取时间对黄姜花根多糖得率的影响,并结合响应面法优化黄姜花根多糖提取工艺,通过测定1,1-二苯基-2-苦肼基(DPPH)自由基和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS^(+))自由基的清除能力研究黄姜花根的抗氧化活性。结果表明:在提取温度83℃、液料比30 mL/g、提取时间172 min的条件下,黄姜花根多糖得率最高,可达9.32%。在一定范围内,黄姜花根多糖清除自由基能力与多糖的浓度呈量效关系,黄姜花根多糖溶液对DPPH自由基和ABTS^(+)自由基的清除率分别为92.58%和91.80%。研究表明,黄姜花根多糖的抗氧化活性较强,可为今后黄姜花根多糖的进一步开发与应用提供参考。

桑黄多糖提取工艺优化、结构表征及抗氧化活性研究

目的以临清桑黄为研究材料,优化桑黄多糖(Sanghuangporus sanghuang polysaccharide-hot water extraction,SSP-W)的制备工艺并研究其结构特征和抗氧化活性。方法以SSP-W提取得率为指标,采用单因素和响应面实验对制备工艺进行优化,采用高效阴离子交换色谱-脉冲安培检测法(high performance anion exchange chromatography-pulsed amperometric detection,HPAEC-PAD)、傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FT-IR)、扫描电镜(scanning electron microscopy,SEM)和X射线衍射(X-ray diffraction,XRD)对其结构进行初步表征。结果最佳制备工艺为:提取时间2.4 h、提取温度95℃、液料比27:1(m L/g),在此条件下,SSP-W提取得率为2.34%。其结构特征为:SSP-W以吡喃环为基本骨架,由岩藻糖、氨基葡萄糖、葡萄糖和甘露糖4种单糖组成。扫描电镜结果表明,SSP-W形状不规则,有明显的孔洞。X-衍射结果表明,SSP-W以结晶态聚合物和非结晶态聚合物的形式共存。抗氧化实验表明,SSP-W具有较强的抗氧化活性,其羟自由基和2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)ammonium salt,ABTS]阳离子自由基的半最大效应浓度(concentration for 50%of maximal effect,EC50)值分别为488μg/m L和75μg/m L,当质量浓度为250.0μg/m L时,ABTS阳离子自由基清除率达到96.27%。结论SSP-W是一种具有抗氧化潜力的活性物质。本研究结果将为临清桑黄多糖的精深加工和高值化利用提供科学依据。

臭参粗多糖热水浸提工艺及抗氧化性研究

为研究臭参多糖提取工艺,以3年生臭参的地下部分为原料,设计提取温度、提取时间和料液比进行单因素实验,在此基础上,进行三因素三水平正交实验优化得到最佳提取工艺,并对提取的粗多糖进行了抗氧化性研究。结果表明,臭参多糖提取的最佳条件为浸提温度为90℃、浸提时间为40min、料液比为1∶60(g∶mL),在此条件下多糖得率为24.61%。在一定浓度范围内,臭参多糖溶液的总还原能力随浓度的增大而增大,总还原能力与浓度之间表现出较好的相关性。臭参多糖与VC(维生素C)对DPPH·(1,1-二苯基-2-苦基肼自由基)清除率在浓度为12mg·mL^(-1)时相近,多糖和VC清除率分别达到96.39%和100%。臭参多糖的提取率较高,抗氧化活性显著,为臭参多糖的开发利用提供依据。

Effect of hot-water extraction of sugar maple on organosolv delignification and lignin recovery

This paper reported a gradual disassembly of the chemical components of hardwood,starting with hot-water extraction(HWE)for the removal of hemicelluloses,followed by organosolv delignification to remove the lignin.Under mild acid conditions,in addition to hemicelluloses,lower molecular weight lignin fractions were removed(~15%of the total lignin)in the HWE pre-treatment;also,the cleavage of the acid-labile lignin-carbohydrate bond took place to some extent.As a result,the HWE pretreatment promoted the subsequent delignification process and facilitated the lignin recovery from the spent liquor,in terms of higher delignification efficiency and higher purity of the lignin recovered from the spent liquor.The effects of the HWE pre-treatment prior to the delignification process were investigated in this study for both the oxygen-pressurized acetone-water(AWO)and the ALCELL processes,with focuses on the delignification efficiency and the properties of the lignin recovered from the process spent liquor.

预处理对热水浸提黄花菜浸膏粉营养组成及生物活性影响研究

本文分别以鲜黄花菜、水焯鲜黄花菜、蒸制-晒干黄花菜、蒸制-晒干-浸泡黄花菜为原料,通过热水浸提法制备了4种黄花菜浸膏粉,比较了四种黄花菜浸膏粉的得率、营养成分及抗氧化活性,通过小鼠急性毒性试验初步评估了其毒性。结果表明:鲜菜浸膏粉、鲜菜脱碱浸膏粉、干菜浸膏粉、干菜脱碱浸膏粉的得率分别为4.90%、1.20%、24.8%、14.84%。4种黄花菜浸膏粉的营养组成及秋水仙碱含量存在显著差异,其中干菜浸膏粉总糖、还原糖、类胡萝卜素、总酚的含量最高,分别为82.1 g/100g、32.28 g/100g、3.81 mg/100g、6.56g/100g,而秋水仙碱含量由鲜黄花菜4.000mg/kg降低为0.010 mg/kg~0.039 mg/kg之间。4种黄花菜浸膏粉的抗氧化活性大小排序为:干菜浸膏粉>干菜脱碱浸膏粉>鲜菜脱碱浸膏粉>鲜菜浸膏粉,其中干菜浸膏粉对DPPH自由基、羟自由基和ABTS自由基的清除率最高,分别为94.5%(IC_(50)为0.167mg/mL)、88.5%(IC_(50)为0.111mg/mL)和86.7%(IC_(50)为0.160mg/mL)。急性经口毒性试验及病理学研究表明,在21 d的观察期内,灌胃了干菜浸膏粉小鼠无死之旦无异常现象,未见脏器异常改变,无病理病变。综上所述,选用蒸制-晒干后的黄花菜,通过提取、浓缩、干燥、粉碎制备的黄花菜浸膏粉营养品质最佳,抗氧化活性强且无毒性,可用于黄花菜新产品的开发。

金银花粗多糖提取工艺优化及其抗氧化活性评价

采用热水提取法提取金银花多糖,通过单因素实验考察料液比、浸提时间、浸提温度和提取次数4个因素对多糖得率的影响,在此基础上利用响应面法对提取条件进行优化。以DPPH自由基、ABTS+自由基、羟基自由基、超氧阴离子自由基清除能力和总还原力为指标评价金银花粗多糖的抗氧化活性。结果表明:金银花多糖的最佳提取工艺条件为料液比1:30(g/mL)、浸提时间120 min、浸提温度70℃,此条件下多糖的实际得率为6.45%±0.15%,与预测值的相对误差为1.2%。当金银花粗多糖浓度为2 mg/mL时,DPPH自由基、ABTS+自由基、羟基自由基和超氧阴离子自由基的清除率分别为88.56%、99.51%、46.40%和85.88%,总还原力为1.04。该方法制备的金银花粗多糖具有较好的抗氧化能力,这为金银花活性多糖的进一步分离、纯化及结构表征提供了理论依据。

春生田头菇粗多糖超声辅助提取及抗氧化性测定

目的:为高效利用洞庭湖特色芦苇食用菌资源,开发食用菌多糖功能性食品。方法:以芦苇食用菌春生田头菇为试验原料,以多糖提取率为指标,采用超声辅助热水提取法进行粗多糖提取,以液料比、超声时间、超声功率、热水浸提温度、热水浸提时间为单因素条件进行试验,依据Box-Behnken中心组合试验设计建立数学模型,优化春生田头菇粗多糖的提取工艺条件,并考察春生田头菇粗多糖对DPPH自由基、ABTS自由基的清除能力。结果:结合实际,最佳提取工艺条件为料液比1∶50(g/mL)、超声提取时间20 min、超声功率150 W、热水浸提温度80℃、热水浸提时间4 h。在此工艺条件下,春生田头菇粗多糖提取率为5.08%。提取的粗多糖对DPPH自由基和ABTS自由基清除率分别为55.05%,58.47%,半抑制浓度IC50为1.03,0.28 mg/mL。结论:春生田头菇多糖在超声辅助热水提取法最佳工艺参数下,提取得率较高,同时该粗多糖具有一定的体外抗氧化能力。

海参肠多糖的提取工艺优化及其理化性质研究

为有效提高海参废弃物利用率,本文以海参肠废弃物为原料,采用热水提取法提取海参肠多糖,结合响应面法优化提取工艺并分析海参肠多糖理化性质。结果表明,海参肠多糖最优提取工艺条件为:提取时间1 h、提取温度80℃、料液比1:8(mg/mL)、重复提取2次,在此条件下多糖的平均得率为4.43%±0.17%。利用高效液相色谱法分析该条件下提取的多糖平均分子量为4.91×10^(6) Da。通过气相色谱法分析海参肠多糖主要由岩藻糖、甘露糖和阿拉伯糖组成,含有部分半乳糖和葡萄糖。采用热重分析仪研究热力学性质,发现温度在309℃时多糖结构发生崩解,在800℃时多糖重量损失为85.46%。运用扫描电子显微镜观察形貌结构,发现多糖表面是由不均匀椭圆形球状颗粒组成。以上结果初步揭示了热水提取海参肠多糖的特性,为海参废弃物资源利用提供了理论基础。