和田玉枣汁浸提工艺的研究

以和田玉枣为原料,以总糖、可溶性固形物含量为指标,通过正交试验确定了和田玉枣汁浸提工艺的最佳参数为：浸提温度70℃、浸提时间70min、料液比1：12。且在此条件下,浸提所得的和田玉枣汁中固形物含量为6．48％,总糖含量为10．78％。     

超滤、纳滤技术分离大枣功效成分的研究

以大枣汁为材料,研究不同截留分子量(10000、5000、800、500 u)的超滤和纳滤膜分离大枣中粗多糖、粗低聚糖和单糖糖浆的效果,筛选了不同截留分子量的超滤膜和纳滤膜,并分别优化操作条件,得到适宜的工艺条件。结果表明:选用10000 u超滤膜,大枣汁可溶性固形物含量为3%,操作压力0.12 MPa;选用500 u纳滤膜,可溶性固形物含量为1.0%,操作压力0.54MPa。在此条件下,粗多糖、粗低聚糖和单糖糖浆的得率依次为5.21%、19.24%和58.27%,纯度可达到52.61%、54.78%和84.00%。     

红枣汁提取工艺优化研究

以干红枣为原料,经清洗、烘干、破碎后,酶法提取枣汁。对利用果胶酶浸提法提取红枣汁的工艺参数进行优化。在单因素试验的基础上,通过响应面法得出最优工艺条件。结果表明,浸提温度为50℃,浸提时间为2.5h,加酶量为0.25%,加水比例为1:8时,红枣汁中的可溶性固形物含量和总酸度均最高。     

红枣汁澄清工艺研究

为制备稳定、澄清透明且营养丰富的红枣汁,将干枣经果胶酶浸提后得到红枣汁。用果胶酶、壳聚糖、硅藻土和膨润土澄清处理红枣汁,以透光率、色泽、贮藏稳定性为指标,比较其澄清效果,研究澄清工艺,并比较澄清前后枣汁的主要营养成分。结果表明:壳聚糖处理后的枣汁,其透光率可达98%以上,亮度最强,L值为51.15±0.16,贮藏一个月后浊度最低,为0.88±0.04;壳聚糖澄清处理后可溶性固形物、总糖和V_C含量保存率较高,均在90%以上。     

不同品种枣果果实品质分析与评价

试验研究6个品种枣果的理化品质特性,评价指标主要包括可溶固形物(TSS)、可滴定酸、糖酸比、还原糖、可溶性糖、有机酸和游离氨基酸。结果表明:葡萄糖、果糖和蔗糖是其主要可溶性糖,且均以蔗糖含量最高;苹果酸和琥珀酸是其主要有机酸,占有机酸总含量92%以上;脯氨酸是其含量最丰富的氨基酸,占总游离氨基酸68%以上,其次是天冬氨酸。梨枣因含水量高,酸度低、可食率高、糖酸比适中,适合鲜食;哈密大枣和木枣含糖量高、含水量低、酸度较高、糖酸比高,适合干制;金丝小枣与灰枣酸度较高,但TSS与糖含量也较高,可鲜食也可干制。     

酶技术在红枣汁提取中的应用研究

以红枣为原料,采用果胶酶酶解浸提的方法制备红枣汁。主要研究了预煮工艺和酶解条件对红枣汁提取效果的影响。结果表明:最佳预煮条件为:预煮温度100℃,预煮时间20 min,料水比为1︰16;酶解浸提的最佳工艺条件为:果胶酶0.3%,酶解温度50℃,酶解时间3 h,酶解pH3。在此最佳工艺条件下做验证试验,枣汁提取率可达51.89%,总糖35.93%,可溶性固形物10.57%,所得枣汁色泽自然、枣香浓郁、具有较好的稳定性。     

梨优良品种制汁性能研究

目的：研究了14 个主栽梨品种的制汁性能,为选择制汁品种和制汁工艺提供依据。方法：从理化指标(总糖、还原性糖、可滴定酸、可溶性固形物、出汁率)、褐变程度(总酚含量、多酚氧化酶活性、OD420nm 值、L 值)和感官鉴评(外观、滋味、气味)3 个方面进行评价。结果：发现果实可溶性固形物变化范围为10.94%～ 13.00%,可滴定酸含量变化范围为0.062%～0.76%。总酚含量和多酚氧化酶活性在果实中分布不均衡,果皮中的总酚含量最高,与果汁的OD420nm 值显著正相关,与L 值极显著负相关。果皮中多酚氧化酶的活性也很高,与果汁的OD420nm 值有显著的正相关性。结论：综合评价,所选14 个梨品种中锦香、黄金、安梨为较好的制汁梨品种。     

杀菌处理对发酵红枣汁品质的影响

目的:对比不同杀菌方式对发酵红枣汁品质的影响。方法:红枣汁发酵前，采用低温等离子体杀菌(CPS)和脉冲强光杀菌(PLS)对发酵前后红枣汁品质的影响，以高压杀菌(SA)红枣汁为对照。结果:采用CPS处理，红枣汁发酵前后总糖、还原糖和可溶性固形物含量均显著高于另外两种杀菌方式，发酵后红枣汁的总糖、还原糖和可溶性固形物含量分别为1.7 mg/L、1.64 mg/L和12.4%;采用SA处理，红枣汁发酵前后总酚含量均为最低，发酵后红枣汁的总酚含量仅为2.19 mg/L;采用PLS处理，红枣汁发酵前后的色差值变化最小。经CPS、PLS和SA处理后的红枣汁，接种植物乳杆菌发酵48 h后，其活菌数均>6.48 lg(CFU/mL),其中，PLS处理后植物乳杆菌活菌总数最高[6.63 lg (CFU/mL)]。结论:非热杀菌处理(特别是PLS)对发酵红枣汁的品质影响较小，可作为发酵红枣汁加工中的杀菌处理技术。     

不同新疆红枣营养成分比较分析

以哈密大枣、骏枣(哈密、阿克苏、和田)、灰枣(若羌、阿克苏、喀什)典型生产区域及品种的7个新疆红枣样品为试材,对其中的营养与功能性成分进行全面比较分析,结果表明:不同生态区域、不同品种新疆红枣的营养品质存在较大差异,但对于不同的营养指标,其影响程度也存在差异。品种是影响新疆红枣糖、酸、氨基酸含量的主要因素,而产地对新疆红枣蛋白质、脂肪、维生素、矿质元素、总酚、总黄酮含量的影响较大。总糖及还原糖含量以灰枣最高,其次为骏枣,哈密大枣最低,而总酸和氨基酸含量以哈密大枣为最高,骏枣次之,灰枣最低。和田骏枣中钙、铁、镁的含量均明显高于其他新疆红枣,可作为补钙、补铁的重要来源。哈密骏枣的总酚含量较高,若羌灰枣、哈密大枣的总黄酮含量较高,可作为提取多酚和黄酮类物质或生产功能性红枣产品的优质原料。     

广西野生毛葡萄两性花品种可溶性固形物含量调查初报

为了解野生毛葡萄两性花品种可溶性固形物含量及变化规律,以3年生野生毛葡萄两性花品种(建园苗木为组培苗)为试材,对其可溶性固形物含量进行初步调查,结果表明:"干"字整形的果穗上层果可溶性固形物含量显著高于下层果,平均高0.52%;大果穗与中果穗可溶性固形物含量均显著高于小果穗;二次结果果穗可溶性固形物、水溶性总糖(以葡萄糖计)和总酸(以酒石酸计)含量高于一次果.     

低共熔溶剂提取绿茶总黄酮及其抗氧化活性

目的:优化低共熔溶剂提取绿茶总黄酮工艺,并评价其抗氧化活性。方法:以总黄酮提取率为考察指标,以低共熔溶剂种类、液料比、提取温度和提取时间为影响因素,采用正交试验优化低共熔溶剂提取绿茶总黄酮工艺参数,并对其抗氧化活性进行评价。结果:绿茶总黄酮的最优提取工艺为以80%乙酰胆碱—乳酸(n_乙酰胆碱∶n_乳酸=1∶1)水溶液为低共熔溶剂,液料比(V_溶剂∶m_绿茶)30∶1(mL/g),提取温度90℃,提取时间75 min,此条件下绿茶总黄酮提取率为1.84%,总黄酮质量浓度为65.8 mg/mL。一定质量浓度范围内,绿茶总黄酮提取液对DPPH自由基和OH自由基的清除能力强于维生素C。结论:以80%乙酰胆碱—乳酸(n_乙酰胆碱∶n_乳酸=1∶1)水溶液为低共熔溶剂提取的绿茶总黄酮具有一定的抗氧化活性。     

Optimization of ultrasonic-assisted extraction of phenolic compounds from <Emphasis Type="Italic">Justicia spicigera</Emphasis> leaves

A Box–Behnken design (Extraction-time, pulse-cycle, sonication-amplitude) was employed to extract phenolic compounds from Justicia spicigera leaves by ultrasonic-assisted extraction. The muicle leaves extracts were analyzed measuring total phenolic compounds and antioxidant capacity. According to response surface methodology the optimal conditions of ultrasonic-assisted extraction to obtain the highest soluble phenolic content were 2 min (extraction time) for 0.7 s (pulse cycle) at 55% of sonication amplitude. Under these optimal conditions, the total phenolic content was higher when was used ultrasonic-assisted extraction (54.02 mg/g) than stirring (46.46 mg/g) and thermal decoction (47.76 mg/g); however, the antioxidant capacity from J. spicigera extracts did not increase by ultrasonic-assisted extraction. The extracts or aqueous infusions from J. spicigera leaves are used for therapeutic proposes, therefore the ultrasonic-assisted extraction is a useful technology to improve the extraction of phytochemicals from J. spicigera leaves.     

Application of response surface methodology to optimize pressurized liquid extraction of antioxidant compounds from sage (Salvia officinalis L.), basil (Ocimum basilicum L.) and thyme (Thymus vulgaris L.)

The present study optimized pressurized liquid extraction (PLE) conditions using Dionex ASE? 200, USA to maximize the antioxidant activity [Ferric ion Reducing Antioxidant Power (FRAP)] and total polyphenol content (TP) of the extracts from three spices of Lamiaceae family (sage, basil and thyme). Optimal conditions with regard to extraction temperature (66-129 °C) and solvent concentration (32-88% methanol) were identified using response surface methodology (RSM). For all three spices, results showed that 129 °C was the optimum temperature with regard to antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of sage and basil extracts were 58% and 60% respectively. Thyme showed a different trend with regard to methanol concentration and was optimally extracted at 33%. Antioxidant activity yields of the optimal PLE were significantly (p < 0.05) higher than solid/liquid extracts. Predicted models were highly significant (p < 0.05) for both total phenol (TP) and FRAP values in all the spices with high regression coefficients (R(2)) ranging from 0.651 to 0.999.     

灵芝多糖不同提取方式的比较研究

目的 比较5种不同提取方式所得灵芝粗多糖的提取得率、理化性质、抗氧化活性, 确定最优提取方式。方法 采用热水浸提法、超声清洗辅助提取法、超声破碎提取法、微波辅助提取法、酶辅助提取法提取灵芝粗多糖, 可分别表示为H-GLP、U1-GLP、U2-GLP、M-GLP、E-GLP, 苯酚-硫酸法测定总糖含量、二硝基水杨酸(dinitrosalicylic acid, DNS)法测定还原糖含量, 比较对2,2-二(4-叔辛基苯基)-1-苦肼基自由基(DPPH?)清除活性, 羟自由基(?OH)清除活性和还原力大小, 分析抗氧化活性, 以傅里叶红外光谱仪(fourier transform infrared spectrometer, FT-IR)和高效阴离子交换色谱(high performance anion exchange chromatography, HPAEC-PAD)进行结构表征。结果 5种提取方式提取得率的大小排列顺序为: M-GLP>E-GLP>U2-GLP> H-GLP>U1-GLP, 其中M-GLP的提取得率最高为3.98%, 其多糖含量为46.80%, 还原糖含量为5.36%。5种方式提取所得粗多糖都体现出一定的抗氧化活性, M-GLP具有较强DPPH?清除活性, U2-GLP具有较强的羟自由基清除活性, 十分接近阳性对照。结论 微波辅助提取法在提取得率和抗氧化活性都优于其他提取方式, 值得进一步开发与利用。     

响应面法优化超声辅助葛根浸提工艺及浸提液抗氧化活性研究

目的采用响应面法优化超声辅助葛根水浸提的工艺,并比较其浸提液的抗氧化活性。方法采用单因素试验结合响应面法,以葛根总黄酮得率为评价指标,对鲜葛根和干葛根超声辅助水浸提工艺进行优化,并测定比较其浸提液的总黄酮含量和抗氧化活性。结果干葛根浸提最佳工艺为：水料比30:1（mL/g）、超声功率310 W、超声时间38 min;鲜葛根浸提最佳工艺为：水料比4.5:1（mL/g）、超声功率442 W、超声时间39 min;在最佳工艺条件下,干葛根和鲜葛根的葛根总黄酮得率分别为（12.68±0.05）mg/g和（4.36±0.04）mg/g。对于同一种葛根,干葛根提取液总黄酮含量和抗氧化能力均高于鲜葛根（P<0.05）;在同一干或鲜状态下,野葛浸提液的总黄酮含量和抗氧化能力显著大于野生粉葛和栽培粉葛（P<0.01）,野生粉葛浸提液的抗氧化能力与栽培粉葛差异不显著（P>0.05）。     

超声波辅助酶法制备北芪菇抽提物及其抗氧化能力研究

为探究北芪菇抽提物制备工艺及抗氧化活性,以氨基态氮含量和可溶性固形物含量为指标,采用单因素实验和响应面法对超声波辅助酶法制取北芪菇抽提物的条件进行优化。结果表明,最佳条件为:纤维素酶用量0.5%、水料比12:1 mL/g、超声时间40 min、超声温度40 ℃、pH4.0,抽提物氨基态氮含量(0.765±0.12) mg/mL,总黄酮含量6.5%±0.25%,可溶性固形物含量为2.0%。以V_C为阳性对照,抗氧化性结果表明酶法抽提物(EE)具有体外抗氧化活性,清除DPPH自由基的能力最强,当质量浓度为600 μg/mL时与同质量浓度的V_C标准品相比,清除能力明显高于对照。本研究可为北芪菇的进一步开发应用提供理论依据。     

Storage stability of sterilized liquid extracts from pomegranate peel

Pomegranate marc, a byproduct of commercial juice production, has shown promise as a starting material for the recovery of health promoting phenolic compounds. The stability of aqueous extracts prepared from pomegranate marc was evaluated in preparation to directly using these extracts as nutraceuticals or food additives. The liquid extracts were produced under extraction conditions of 25 °C, water to peel ratio of 50 : 1 (w/w) for 2 min, and then sterilized at 121 °C for 10 s. Storage conditions tested included 3 different pH values (3.5, 5.0, and 7.0) and 2 packaging methods (no light and exposure to light). The extracts were evaluated for industrial (pH, total soluble solid content, and clarity), color, spectral, and antioxidant characteristics over a period of 180 d. The results showed that both pH value and packaging method significantly influenced the industrial and color characteristics of the extracts. The high pH had a negative effect on spectral and antioxidant characteristics. Therefore, the recommended storage conditions are low pH and with dark packaging to maintain the high storage stability. After 180 d of storage, extracts stored at low pH (3.5) in dark packaging still retained 67% and 58% of their total soluble phenolic concentration and antioxidant activity, compared with 61% and 43% for high pH (7.0) samples, and were composed of high concentrations of punicalagins A and B, gallic, and ellagic acids. PRACTICAL APPLICATION: The present research developed an effective recovery of phenolic compounds from pomegranate marc to be used as nutraceuticals or food additives. The aqueous extract product has good quality characteristics with high industrial and color stability, and total phenolic content and antioxidant activity, when stored at pH 3.5 in dark packaging for up to 180 d. The evaluation results of storage stability reported here are important for commercialization.     

蔗梢多酚提取工艺及抗氧化活性研究

植物多酚具有独特的生理活性和药理活性的天然产物,甘蔗的蔗梢部分多酚含量很高,但一般作为燃料直接燃烧,研究多酚的提取方法并研究其活性有一定的研究价值。在单因素试验的基础上采用正交试验得到了蔗梢多酚的最佳浸提工艺:浸提溶剂为60%乙醇,以1∶4固液质量比在60℃提取2h,在此条件下,蔗梢多酚浸提率为183mg/100g蔗梢。抗氧化活性实验表明,蔗梢多酚对花生油的抗氧化活性与VE接近。VC对其有明显增效作用,添加少量VC后,蔗梢多酚的抗氧化活性明显优于VE。     

超声波法提取水溶性茯苓多糖工艺优化及其抗氧化活性探究

以九资河茯苓为原料,采用超声波法提取茯苓多糖。以茯苓多糖得率为响应值,采用单因素试验及响应面试验对超声波提取茯苓多糖的工艺条件进行优化,并对其抗氧化活性进行研究。结果表明,超声波提取茯苓多糖的最佳工艺条件为超声波功率200 W,料液比1∶34（g∶mL）,超声时间11 min。在此最优提取条件下,茯苓多糖得率为2.08%,较优化前（1.68%）提高16.85%。当茯苓多糖质量浓度为3.0 mg/mL时,总抗氧化能力最高,为0.22;当茯苓多糖质量浓度为2.5 mg/mL时,茯苓多糖对1,1-二苯基-2-苦肼基（DPPH）自由基的清除率最大,为13%,但均低于阳性对照维生素C。