蔷薇果汁、余甘果汁和桔皮粉对大鼠体内N—亚硝基脯氨酸合成的阻断作用

本文观察了蔷薇果汁、余甘果汁及桔皮粉阻断大鼠体内 N—亚硝基脯氨酸(NPR0)合成的作用。结果表明,3ml 蔷薇果汁或余甘果汁(含维生素 C36μmol)能完全阻断40μmolL—脯氨酸、亚硝酸钠在大鼠体内合成 NPRO,阻断率分别达96._4%和100.3%。效果强于同量维生素 C 的作用(阻断率86.5%)。0.5g 桔皮粉(含维生素 C1.4μmol)也能发挥有效的阻断作用,阻断率为65.5%。本研完提示,蔷薇果汁、余甘果汁及桔皮粉中还含有维生素 C 以外的其它阻断成分。     

亚硫酸氢钠、没食子酸丙酯阻断大鼠体内N－亚硝基脯氨酸的合成

以２４小时尿中Ｎ－亚硝基脯氨酸（ＮＰＲＯ）排泄量为指标，研究亚硫酸氢钠（ＮａＨＳＯ３）和没食于酸丙酯（ＰＧ）阻断大鼠体内Ｎ－亚硝基脯氨酸合成的作用。结果证明１７．５ｍｇＮａＨＳＯ３、５ｍｇＰＧ能有效地阻断４０μｍｏｌ脯氨酸和４０μｍｏｌ亚硝酸钠在大鼠体内合成ＮＰＲＯ，阻断率分别为９９．７８％和９２．９８％。     

亚硫酸氢钠、没食子酸丙酯阻断大鼠体内N—亚硝基脯氨酸的合成

以24小时尿中N－亚硝基脯氨酸（NPRO）排泄量为指标，研究亚硫酸氢钠（NaHSO3)和没食子酸丙酯（PG）阻断大鼠体内N－亚硝基脯氨酸合成的作用。结果证明17.5mgNaHSO3,5mg PG能有效地阻断40μmol脯氨酸和40μmol亚硝酸钠在大鼠体内合成NPRO，阻断率分别为99．78％和92．98％。     

余甘果汁阻断胃癌高发区人群内源性N—亚硝基化合物合成

本文观察了余甘果汁对胃癌高发区受试者内源性 N—亚硝基化合物(NOC)合成的阻断作用。受试者餐后服用16.5ml 余甘果汁后.空腹胃液中挥发性亚硝胺(VNA)总量由平均1.64±1.18ppb 显著下降至0.25±0.23ppb(p<0.01);300mg 脯氨酸负荷后的24小时尿 N—亚硝基脯氨酸(NpRo)排出量由7.5±4.3uy 下降至1.8±1.0ug(p<     

广西白毫茶阻断N－亚硝基吗啉合成的研究

广西白毫茶阻断Ｎ－亚硝基吗啉合成的研究梁学军北京医科大学（１０８０８３）绿茶能阻断Ｎ－亚硝化反应，已屡有报导。广西白毫茶属绿茶中的一个品种，风味独特。为探讨其对Ｎ－亚硝基化合物合成的阻断作用，我们以广西凌云、玉洪、西林、德保、靖西、右江不同产地的六种...     

猕猴桃浓缩汁的生产开发

猕猴桃果汁，含丰富的糖、有机酸、脂肪、氨基酸、维生素、矿物质等营养成份，酸甜适口，风味独特。近年来的科学研究证明，经常服用猕猴桃果汁，可以有效地防治心血管疾病、尿道结石、肝炎，降低人体内胆固醇含量，并能阻断致癌物质N－亚硝基吗啉的合成。因此，研究开发猕猴桃     

影响草莓果汁红色素变化的因子研究

通过试验对草莓果汁在加工及继后贮藏过程中，影响红色素变化的因子进行了研究。结果表明，迅速加热果实温度到６０℃，有利于提高果汁中红色素含量；向果汁中分别加入０．１－０．４％的抗坏血酸，酒石酸和柠檬酸对果汁具有明显的增色作用；而加入１．０－１５．０％的葡萄糖和蔗糖对果汁颜色没有影响；调整果汁ＰＨ值到４．０以下有助于保持果汁的固有颜色；采用低温避光贮存果汁可延缓草莓果汁红色素的降解。     

醋柳果汁对N-亚硝基化合物体内外形成的影响

醋柳又称沙棘或者醋柳,其果实含有多种营养成分,为广泛开发和利用,我们对其阻断体内外N-亚硝基化合物合成的作用进行了初步研究。     

秋子梨带肉果汁的生产工艺

在秋子梨带肉果汁的梨汁提取工艺中，加0．2％的果胶酶制剂，可使出 汁率提高20％左右。为防止褐变，在榨汁的同时，加入0．04％的抗坏血酸，这样榨出的汁液色泽为淡黄色至黄白色。生产工艺中采用先脱的气后均质的工序，可保持果汁色泽，减少VC的损失。添加稳定剂和两次均质可以改善饮料的悬浮稳定性。如单独使用CMC－Na，浓度为0．2％；如琼脂与CMC－Na配合使用，浓度各为0．1％。均质条件：第一次均质压力为16．4MPa，第二次均质压力为11．8MPa，均质温度为60℃，杀菌处理温度以112℃以上较为理想，既达到了杀菌的目的，又较好地保持了带肉果汁的稳定性及营养成分。     

野木瓜果汁体外抗氧化性研究

以抗坏血酸为参照,通过体外抗氧化实验评价野木瓜果汁抗氧化能力;比较未抑制褐变和抑制褐变果汁与鲜果汁的抗氧化能力,以评价褐变及抑制褐变对果汁抗氧化能力的影响。结果表明:浓度为100%的野木瓜果汁总还原力、对·OH、O_2~-·及亚硝酸盐的清除率比0.8 mg/m L抗坏血酸低7.26%、7.29%、11.80%、9.92%(p0.01),对亚硝胺合成阻断率与抗坏血酸无显著差异(p=0.5714);鲜果汁的总还原力、对·OH、O_2~-·、亚硝酸盐的清除率及亚硝胺合成阻断率分别高出褐变果汁19.65%、100.50%、22.31%、20.62%、13.33%(p0.01);抑制褐变果汁与鲜果汁在总还原力、清除亚硝酸盐和阻断亚硝胺合成上均无显著性差异(p0.05),对O_2~-·和·OH的清除率低于鲜果汁2.74%和6.95%(p0.01)。野木瓜果汁具有较强的抗氧化能力,褐变降低了果汁的抗氧化能力,抑制褐变能较好地保全果汁的抗氧化功效。     

蓝莓果汁及不同纯度蓝莓花色苷对原发性高血压大鼠血压的影响

以蓝莓果汁及不同纯度的蓝莓花色苷提取物为原料灌胃12 周龄原发性高血压大鼠（spontaneouslyhypertensive rats,SHR）和Wistar大鼠,研究花色苷提取纯化对其降压效果影响。采用蓝莓果汁（A组）（花色苷的质量分数为1.00%）及不同纯度的蓝莓花色苷提取物（花色苷的质量分数分别为8.66%（B组）、38.49%（C组）、94.42%（D组））灌胃SHR,灌胃剂量以花色苷含量计。其中,A组的灌胃剂量为94.4、472.1、944.2 mg/kg（以体质量计,下同）,B组的灌胃剂量为10.9、54.5、109.0 mg/kg,C组的灌胃剂量为2.5、12.3、24.5 mg/kg,D组的灌胃剂量为1.0、5.0、10.0 mg/kg。结果表明：同剂量（花色苷当量）的蓝莓果汁与蓝莓皮渣提取物（不同纯度蓝莓花色苷提取物）相比,其对SHR的降压效果有显著差异（P＜0.05）,而同剂量不同纯度的蓝莓皮渣提取物对SHR的降压效果无显著差异（P＞0.05）。其中,高剂量果汁（A组）和不同纯度蓝莓花色苷提取物（B、C、D组）灌胃SHR,灌胃后4或5 h其收缩压分别降低了38.45、32.57、33.09、33.41 mmHg。因此,蓝莓对高血压改善作用的功能成分是花色苷;蓝莓果汁的其他成分对花色苷的降血压功能有增强作用。     

Physicochemical,melting and sensory properties of ice cream incorporating processed ginger (Zingiber officinale)

Ginger juice and paste (from 2 to 8%, ginger candy from 5 to 20%, and ginger powder from 0.5 to 2%) were incorporated into the ice cream mix prior to freezing. Inclusion of the juice and paste reduced total solids, fat, protein and overrun, and increased antioxidant activity and phenols, whereas the ginger candy and powder increased solids, crude fibre, antioxidant activity and phenols, and diminished fat and overrun. Acidity increased with the ginger juice and powder, whereas it decreased with the ginger paste and candy. First dripping time amplified and melting rate declined with all the ginger preparations. Ice cream containing ginger juice, paste, candy and powder at 6, 4, 10 and 1%, respectively, achieved the highest overall acceptability scores.     

Free radical scavenging, angiotensin I-converting enzyme (ACE) inhibitory, and in vitro anticancer activities of ramie (Boehmeria nivea) leaves extracts

The objectives of this study were to evaluate the antioxidant activity, angiotensin I-converting enzyme (ACE) inhibitory activity, and anticancer activity of ramie (Boehmeria nivea) leaves (RL). The RL was extracted with 70%(v/v) ethanol (RLE) and fractionated with the solvents of hexane, chloroform, ethylacetate, and aqueous. The ethylacetate fraction (EF) contained the highest phenolic contents of 651.65 mg/g, followed by RLE of 148.72 mg/g. The EF showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging with a 50% inhibition concentration (IC₅₀) of 0.097, 0.129, and 0.191 mg/mL, respectively. The ACE-inhibitory activity of EF was 80.32% at a concentration of 0.1 mg/mL. The EF showed growth-inhibitory effect of 67.21% at 0.25 mg/mL on the LoVo cell line, and 56.08% at 0.25 mg/mL on the NCI-H460 cell line, respectively. Therefore, it was suggested that the RL were potential materials for use as functional food and medicine.     

Total phenolics,ascorbic acid,and antioxidant capacity of noni (Morinda citrifolia L.) juice and powder as affected by illumination during storage

Total phenolics, ascorbic acid, and antioxidant capacity of noni (Morinda citrifolia L.) juice and powder were determined during storage at 24 °C. After 2 weeks of storage, illuminated noni juice lost 32% of total phenolics, 89% of ascorbic acid, and 46–65% of antioxidant capacity—about 8%, 22%, and 9–15% more than unilluminated juice. Both illuminated and unilluminated juice lost 97% of ascorbic acid by 4 weeks. The difference in antioxidant characteristics between illuminated and unilluminated juice became insignificant at 12 weeks. After 12 weeks, illuminated noni powder lost 21% of total phenolics, 17% of ascorbic acid, and 23–36% of antioxidant capacity—about 13%, 4%, and 7–19% more than the unilluminated powder. Noni powder in brown bottles retained antioxidant characteristics significantly greater than that in clear bottles. Protection from light effectively reduced degradation of antioxidant characteristics of noni juice for only 2 weeks but those of noni powder for at least 3 months.     

雪莲果系列制品的研制

为提高雪莲果的利用价值和开发新的功能性食品,以新鲜雪莲果为原料,榨汁后滤液喷雾干燥制备雪莲果汁粉,滤渣制备雪莲果渣粉。考察了护色剂对雪莲果汁粉及出粉率的影响,并对产品中低聚果糖的含量进行了测定。再以玉米胚芽油为芯材,雪莲果汁及其他材料为壁材,采用微胶囊技术研发新型的功能性雪莲果汁粉末油脂。结果表明:0.20%的柠檬酸护色效果较好,制备的雪莲果汁粉末油脂表面油含量2.11%,包埋率92.6%,冲溶后的乳状液有雪莲果香且稳定性好。     

Glass Transition Behavior of Spray Dried Orange Juice Powder Measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)

Spray drying behavior of orange juice concentrate with various levels of maltodextrin (DE 6) was studied. Five combinations of orange juice concentrate and maltodextrin (25:75, 30:70, 35:65, 40:60, and 50:50) were spray dried at 160 and 65°C inlet and outlet temperatures, respectively. The product recovered with 50% maltodextrin concentration was sticky and only 20% powder was recovered. The recovery of orange juice powder increased as the amount of maltodextrin in powders increased. The particle size and bulk density remained almost the same in all except in 50% maltodextrin powder which was slightly larger and more dense. The moisture content of spray dried powders was high and desiccated before measuring glass transition temperature. The anhydrous spray dried powders showed increased T_g values with increasing maltodextrin concentration, from 66°C in 50% maltodextrin to 97°C in 75% maltodextrin containing powders. The glass rubber transition (T_g-r) values of all the products measured using novel Thermal Mechanical Compression Test (TMCT) were higher than T_g values measured by DSC; the difference in values increased with increase in maltodextrin concentration.     

应用PCR技术鉴定豆奶粉、奶粉及果汁饮料中的有效成分

应用PCR技术对日常生活中几种常见的与人类健康和安全有关的豆奶粉、奶粉及果汁饮料等加工食品中的有效成分,包括大豆凝聚素(Lectin)基因、牛线粒体基因、植物叶绿体rbcL基因以及真核生物中普遍存在的核糖体DNA(18SrDNA)片段等进行检测,建立了这些样品的DNA提取、纯化以及单PCR和二重PCR检测技术体系。结果表明:应用单PCR技术和二重PCR技术检测样品的结果一致,且稳定、重复性好。     

浑浊型光皮木瓜果汁的稳定性研究

浑浊型光皮木瓜果汁中由于不溶性固形物含量较高,对产品的稳定性提出了更高要求。以新鲜光皮木瓜为原料,研究了取汁方式、不同稳定剂和杀菌方式对果汁稳定性的影响。结果表明,打浆取汁的不溶性固形物含量为（36.56 ± 1.27）%,显著高于压榨法,更有利于产品香气、营养成分等的保留;黄原胶、瓜尔豆胶、结冷胶最适复配添加量分别为0.02%、0.02%、0.10%时,果汁的加权稳定性最高,其中黏度值为（23.55 ± 0.78）mPa·s,悬浮稳定性为（94.19 ± 0.91）%;果汁经高温短时杀菌（121 ℃/0.1 MPa/30 s）,贮藏期40 d以内果汁菌落总数均低于限值（2 lg CFU/mL）,悬浮稳定性保持至（65.17 ± 0.83）%,显著高于巴氏杀菌,感官品质处于较好的水平（感官评分>8）。该研究为提高果汁在加工与贮藏中的稳定性提供理论依据。     

5-(4-(2-甲氧二氧)苯烯)-2-硫代噻唑-4-酮对雪莲果中酪氨酸酶的抑制作用

通过分光光度法探究5-(4-(2-甲氧二氧)苯烯)-2-硫代噻唑-4-酮(MBTO)对雪莲果中酪氨酸酶的抑制作用。结果表明：MBTO对雪莲果中酪氨酸酶有良好的抑制作用。单因素试验最佳抑制剂浓度为30.0μmol/L、最佳作用时间为210s、最佳作用温度为30℃。通过三因素三水平正交试验,分析得最佳反应条件为：pH7.5、抑制剂MBTO浓度30.0μmol/L、作用时间330s、作用温度30℃,可达到最佳抑制效果,在此条件下MBTO对雪莲果中酪氨酸酶的抑制率达84.24%。     

雪莲果汁褐变抑制条件的优化研究

研究了抑制雪莲果汁褐变的条件,通过单因素试验选取各因素的水平,根据Box-Benhnken 的中心组合试验设计原理,利用SAS 软件进行响应面回归分析,以褐变变化率为响应值,确定了雪莲果汁褐变抑制条件中各影响因素的水平,结合验证实验结果得到了最佳条件,即抗坏血酸0.31%、DL- 苹果酸0.30%、L- 半胱氨酸0.30%、漂烫温度89℃、褐变变化率20.88%。