GC-MS分析白术炮制前后化学成分的变化

目的研究白术经不同方法炮制后化学成分的变化。方法应用不同炮制方法对净制后的白术饮片分别进行土炒、麸炒、炒黄和炒焦,用水蒸气蒸馏法从炒制品中提取挥发油,测定含量,并用气相色谱-电子轰击质谱联用仪分析。结果白术经不同炒制方法炮制后挥发油得率显著变化,但在各种挥发油中含量均最高。增加6种新成分,3种成分消失。结论白术经炮制后可以影响挥发油的含量和种类。     

山药软饮料研究进展

山药含有多种具有生物活性的化学成分,且具有很高的营养及药用价值,因此以山药为原料进行食品及饮料的研发具有很高的商业价值。山药软饮料大体分为四类:山药原汁饮料、复合型山药饮料、山药发酵饮料以及山药固体饮料,总结与归纳了不同分类山药软饮料的配方、工艺及特点,并对未来的研究方向进行展望。     

不同生长期怀山药化学成分分析

研究不同生长期怀山药化学成分积累规律,为怀山药科学食用、合理采收、规范化种植提供理论依据。怀山药的主流品种是怀山药(品种)和铁棍山药,在不同生长时期采集这两个品种怀山药,测定其折干率和浸出物,应用苯酚-浓硫酸法测定山药多糖的含量,应用高效液相色谱法对山药化学成分尿囊素、腺苷、单糖和寡糖进行含量测定。结果表明:怀山药(品种)折干率9月至12月呈上升趋势,之后趋于平稳,到次年2月底有所下降;铁棍山药折干率9月至11月中旬呈上升趋势,之后趋于平稳。不同化学成分变化较大,整体来说怀山药化学成分含量呈上升趋势,12月份之前波动较大,之后趋于平稳。怀山药(品种)在12月中旬适合采收,结合产地因素,可过冬后采收,但是建议在次年3月前采收完毕,以免产量和有效成分含量降低;铁棍山药12月中旬适宜采收。     

基于UPLC-Q/TOF-MS/MS和生物信息学探讨铁棍山药皮中化学成分的药用和营养价值

目的：系统分析并识别出铁棍山药皮中的化学成分,探讨其药用和营养价值。方法：采用超高效液相色谱-飞行时间串联质谱技术（UPLC-Q/TOF-MS/MS）对铁棍山药皮中的化学成分进行分析,根据化合物一级、二级质谱信息,与参考文献和数据库进行比对,确认所含化合物。利用生物信息学方法,对潜在活性成分进行靶点预测、京都基因与基因组百科全书（KEGG）通路富集分析,发挥作用的重要靶点筛选以及其作用机制的探讨。结果：从铁棍山药皮中共鉴别出33种化合物,其中芹菜素、金合欢素、甘草素、山药素Ⅰ等化合物为铁棍山药皮中潜在的发挥功效的重要化合物,通路富集分析表明铁棍山药皮主要作用于细胞信号通路、癌症和代谢类等疾病相关通路。结论：本研究基于UPLC-Q/TOF-MS/MS结合生物信息学方法,为铁棍山药皮的成分识别、活性物质筛选、潜在药用和营养价值及进一步的开发利用提供了重要参考。     

基于主成分分析的糖尿病专用山药品种筛选

选取山东、河南、湖北等地有代表性的10个山药品种,测定影响山药品种筛选的主要营养成分,然后对各指标进行主成分分析,通过主成分分析筛选出一种适宜糖尿病人食用的山药品种。结果表明,主成分分析法提取了5个主成分,累积贡献率达93.68%,可较好反映山药品质的绝大部分信息。快消化淀粉含量、多糖含量、直链淀粉含量、皂苷含量、淀粉含量为影响山药品质的主要因子。用5个主成分代替原来的12个品质因子对山药进行综合评判,在分析结果的基础上建立主成分综合得分模型,主成分综合得分最高的是长山细毛山药,为1.175。筛选出适宜糖尿病人食用的山药品种:长山细毛山药。     

南瓜红糖蜜枣汤调理气血等10则

正·大病初愈者可服益气健胃汤大病初愈者需顾护后天之本,开脾助运,扶正增食,可取蜜炙黄芪10～15克,党参15克,麸炒白术12克,茯苓10～15克,炒山药12～15克,白豆蔻9克,陈皮6～10克,炒谷芽、炒麦芽各6～10克,炙甘草6～9克,以水煎服,每日1剂。头煎、二煎药液相混,去渣重煎5～8分钟,分早、中、晚3次服用。     

不同品种小麦麸皮、次粉组分分析研究

通过对6个品种小麦的10种麸皮、5种次粉所进行的组分分析发现,不同品种小麦麸皮、次粉的基本化学成分含量差别较大.中糯1号粗麸的灰分含量明显低于其他样品,而蛋白质、粗淀粉含量大大超过其他品种麸皮;中糯1号次粉的灰分、粗脂肪含量均低于其他品种,而粗淀粉含量大大高于其他品种.强筋小麦粗麸、细麸的还原糖含量均较其他品种高.     

山药

山药是一种常用的中药,营养丰富,具有较高的药疗价值,现对山药的化学成分、药理作用、临床应用的研究进展作一介绍。     

基于叶绿体rpoC1序列在山药分子鉴定中的应用

目的 研究基于rpoC1序列分析,建立山药物种鉴定的新方法。方法 利用DNA条形码技术对收集到的7个山药样本提取基因组DNA,以rpoC1基因引物进行PCR扩增、测序,将所得序列在NCBI数据库进行Blast比对,同时从GenBank数据库下载薯蓣属、木薯属和番薯属rpoC1序列,应用MEGA7.0软件计算种内和种间的(K2P)遗传距离,并构建邻接(NJ)系统聚类树。结果 7个山药样本rpoC1基因获得成功扩增和测序。7个山药rpoC1序列及GenBank下载9个薯蓣rpoC1序列和2个木薯番薯rpoC1序列分析显示,山药样本最大种内K2P遗传距离0.009远远小于山药与木薯番薯的种间K2P遗传距离0.104~0.118,同时也小于山药与盾叶薯蓣和穿龙薯蓣的种间K2P遗传距离0.026~0.035,构建的系统发育树显示山药与盾叶薯蓣和穿龙薯蓣、木薯和番薯单独聚为一类。结论 rpoC1序列可为食用山药物种鉴定提供新的分子鉴定方法。     

山药中主要功能性成分及其作用机制研究进展

山药作为药食同源性植株,在我国食用历史悠久,种植十分广泛。山药中含维生素、氨基酸、蛋白质、矿物质、微量元素、皂苷、多糖、多酚类等营养及功能性成分,具有调节肠道菌群、增强机体免疫、防癌、抗氧化、降压降脂等多种保健功能。本文结合近几年的研究成果,归纳总结了山药中的多糖、多酚类、薯蓣皂苷及尿囊素等几种主要的功能性成分及生理活性的作用机制,并对其深入研究提出见解,以期为山药及其功能性成分的进一步开发提供理论基础。     

速冻预制淮山黄花菜饼的煎制工艺研究

以新鲜淮山、干黄花菜和面粉为主要原料,研究一种速冻预制淮山黄花菜饼的煎制工艺。确定基础配方为淮山浆∶面粉∶水为1∶1∶1,并添加20%的黄花菜丁和1%的食盐。通过单因素试验和正交试验对煎制工艺参数进行了优化,确定最佳工艺条件为黄花菜沸水预煮7min,煎饼煎制温度150℃,单面煎制时间210s,厚度1.2cm(面糊45g)。此工艺条件下的产品色泽黄亮,外酥里嫩,甜咸适口,包装后经速冻可贮藏在-18℃条件下。     

Effects of frying and storage at room temperature on the chemical composition and quality of sweet potato slices

Fried sweet potato slices were prepared from yellow (Mabrouka) and orange (Abees) tubers. Some chemical and organoleptic qualities were studied. Changes in these qualities which occurred during storage for 3 months at room temperature were also investigated. The results obtained led to the following conclusions: 1. Sweet potato slices had moderate amounts of calcium and phosphorus, and there was no significant difference in mineral content between fresh and fried sweet potato slices. 2. Sweet potato slices contained a fair amount of essential amino acids, especially leucin, valine and lysine, whereas tryptophan and sulphur amino acids were the limiting amino acids. 3. Sliced sweet potato of yellow variety (Mabrouka) dipped in water, then deep fried in cotton seed oil at (180 ± 5)°C for 1.25 min was organoleptical proved to be the best compared with those prepared from orange variety (Abees), or of yellow variety but dipped in 1% citric acid. 4. Storage of fried sweet potato slices (Mabrouka) in polyvinyl packages at room temperature led to gradual increases in their moisture content and peroxide value, while carotenoids content decreased. Furthermore, the fried sweet potato slices were acceptable until the 10th week of storage, then a rancid taste begins to appear.     

DEEP-FAT FRYING OF YAM SLICES: OPTIMIZATION OF PROCESSING CONDITIONS USING RESPONSE SURFACE METHODOLOGY

The deep-fat frying of yam slices was investigated with the aim of optimizing the processing conditions. During frying, frying temperature, initial dry matter and frying time have a significant effect on moisture loss and oil uptake. Response surface methodology central composite rotatable design was used to study the effects of the independent variables on quality attributes of yam chips. Breaking force, oil content, moisture content and color parameters were determined. Statistical analysis with response surface regression showed that breaking force, oil and moisture contents and color parameters ( L* and a* ) were significantly ( P <  0.05) correlated with frying temperature, initial dry matter and frying time. The optimum conditions were a frying temperature of 175–180C, using tubers of initial dry matter of 0.179–0.214 kg/kg with a frying time of 4–5 min. It was suggested that the regression equation can be used to estimate the dependent variables for fried yam chips except b* (yellowness) parameter.

PRACTICAL APPLICATIONS

It is expected that the optimized processing conditions highlighted in this work will be useful in obtaining fried yam chips of acceptable quality attributes. This optimized condition would be a good prospect for commercialization in small-scale industries.     

EFFECTS OF PREFRY DRYING METHODS ON THE QUALITY OF DEEP FAT FRIED ONION SLICES

Deep fat fried onion slices are used widely as a condiment for hot-dogs and other types of bread and meat combinations in Denmark, Netherlands and Germany. Since there is a consumer demand for food products, high in both sensory and nutritional quality, the effect of prefry drying on the oil content and the color of the fried product was investigated. In order to reduce the oil content in the fried product, raw sliced onions were prefry dried by (1) hot air in a forced air convection oven, (2) microwaving in an oven with a conveyor belt, or (3) freeze dried. For each of the three methods a series of eight batches ranging from 13–30 % dry matter content in the raw onions were obtained. The product that was dried by hot air before frying was lighter than the product prefry dried by microwaving. The product of the freeze dried material was heterogeneous, and the results were excluded. The fried product from dried raw onions, showed the moisture content to be independent of the manipulated dry matter content. The oil content was reduced from about 55% to about 49%, as a result of increasing the dry matter content; however the surface color became darker (L-value was reduced about 6 point).     

稻米油的营养成分、制取工艺及应用研究进展

稻米油不仅富含不饱和脂肪酸,还富含谷维素、植物甾醇等多种脂质伴随物,对人体健康十分有益。随着大健康产业的快速发展,稻米油的提质制取及高值化利用已成为大型油脂加工企业及科研者研究的热点。综述了稻米油中不饱和脂肪酸、谷维素、植物甾醇、角鲨烯、维生素E等营养成分的含量及功能,并对米糠稳定化处理、稻米油制取工艺及稻米油在煎炸食品、乳液递送、生物能源等方面的应用进行了梳理,旨在为稻米油的加工利用提供一定的理论基础及技术指导。     

Oxidative stability of fried dough from rice flour containing rice bran powder during storage

The aim of this study was to evaluate the efficiency of rice bran powder on lipid peroxidation inhibition of fried dough from rice flour during storage. Rice flour dough containing rice bran powder at 5, 10 and 15 g rice bran powder/100 g mixed rice flour were fried in soybean oil at 160 °C for 1 min and stored in dark at 60 °C for 10 days. Lipid peroxidation of fried dough was determined by change of fatty acid compositions, oxygen absorption in vial headspace, lipid hydroperoxides, TBA values including decreasing tocopherol and gamma-oryzanol contents during storage. Polyunsaturated fatty acid decreased rapidly in fried dough without rice bran powder, while an increase of oxygen absorption in vial headspace, lipid hydroperoxide and TBA values were significantly lower (p?0.05) in fried dough containing rice bran powder. In addition, tocopherol degradation was significantly lower in fried dough containing rice bran powder during storage (p?0.05). However, there was no significant difference in gamma-oryzanol contents among fried dough during storage (p>0.05). These results demonstrated that rice bran powder shows the antioxidative effects on fried dough during storage.     

Study on the physicochemical properties and in vitro digestibility of starch from yam with different drying methods

Four methods were applied to dry yam slices, and then, starches were isolated from dried yam slices. Starch isolated from fresh yam was as the study control, and physicochemical properties and in vitro digestibility of starches were studied. The results showed that the amylose content ranged from 12.62% to 28.25%, water‐binding capacity (WBC) from 111.67% to 262.88%, paste clarity from 2.1% to 6.23%, resistant starch (RS) from 66.60% to 88.49% and crystallinity from 11.27% to 25.52%. Compared with the control starch, hot air‐drying at 60 °C significantly decreased amylose content, paste clarity, RS and crystallinity, while increasing the WBC. Low levels of rapidly digestible starch and glucose and high RS levels were found in the starch from freeze‐drying yam. Digestibility of the starches was significantly correlated with amylose content, WBC, paste clarity and swelling power. The starch samples were divided into three groups by principal component analysis (PCA).     

鲜切高山野山药片微波间歇干燥特性研究

为深入研究高山野山药的干燥特性,自制微波间歇干燥试验装置,采用四因素四水平(微波功率、切片厚度、加热时间、间歇时间)对鲜切高山野山药片进行微波间歇干燥试验,得出鲜切高山野山药片微波间歇干燥的干燥变化规律,并对结果进行分析。结果表明:高山野山药片微波间歇干燥过程大致包括加速、恒速和降速阶段;并且加热时间为7s时干燥色泽最好,此时切片厚度对收缩特性产生显著影响,提高切片厚度有利于保持高山野山药片的干后体积。该研究结果对于了解干燥高山野山药乃至相关农产品的过程具有一定的指导意义。     

Modeling water loss and oil uptake during vacuum frying of pre-treated potato slices

The objective of this research was to determine the kinetics of water loss and oil uptake during frying of pre-treated potato slices under vacuum and atmospheric pressure. Potato slices (diameter: 30 mm; width: 3 mm) were pre-treated in the following ways: (i) raw potato slices “control”; (ii) control slices were blanched in hot water at 85 °C for 3.5 min; (iii) blanched slices were dried in hot air until reaching a moisture content of ∼0.6 g water/g dry basis. The slices were fried under vacuum (5.37 kPa, absolute pressure, at 120, 130 and 140 °C) and atmospheric conditions (at 180 °C). Two models based on the Fick's law were used to describe water loss: (i) with a constant effective diffusive coefficient; and (ii) with a variable effective diffusive coefficient. Oil uptake data were fitted to an empirical model, with a linear behavior for short times whereas the model was time independent for long times. The variable diffusivity model better fitted experimental water loss, giving values of effective diffusivity between 4.73 × 10⁻⁹ and 1.80 × 10⁻⁸ m²/s. The proposed model for the study of the kinetics of oil uptake fitted the experimental data properly. Control and blanched vacuum fried potato chips increased their final oil contents to 57.1% and 75.4% respectively, when compared with those fried at atmospheric pressure. However, the oil absorption of dried vacuum fried potato chips diminished by ∼30%.