鲮鱼油炸过程中棕榈油指标的变化与控制

本研究对鲮鱼油炸过程中棕榈油指标的变化进行了感官及理化分析,并采用"Dalsorb吸附剂+板框过滤"的方法,对油炸后的棕榈油进行处理。结果表明:随着油炸时间的延长,棕榈油色泽逐渐加深、流动性及透明度逐渐变差,并且有大量鱼渣出现;棕榈油的酸价、羰基价、极性组分随油炸时间的延长不断增大(酸价由初始0.06 mg KOH/g上升至2.34 mg KOH/g,羰基价由初始3.64meq/kg上升至17.70 meq/kg,极性组分由初始3.07%上升至15.1%),过氧化值的变化无明显规律;其中酸价、极性组分变化更接近国标上限,可优先做为评价指标,但考虑到极性组分检测时间长的原因,建议在线监控以酸价指标为主。采用"Dalsorb吸附剂+板框过滤"的方法,能够明显的降低煎炸后棕榈油的酸价指标(酸价由2.36 mg KOH/g下降至1.50 mg KOH/g),对羰基价和极性组分的处理效果不明显。     

棕榈油脱臭馏出物的阳离子交换树脂催化酯化反应研究

以强酸性阳离子交换树脂为催化剂,经过自制的固定床反应器,使棕榈油脱臭馏出物（PODD）中的脂肪酸与甲醇起酯化反应,合成脂肪酸甲酯.结果表明,酯化反应的最佳物料比为m甲醇/m原料=2;反应温度在甲醇正常沸点以下时,反应温度越高,酯化率越大;酯化率随催化反应时间增大而增大,但增大速度逐渐趋缓.当在常压下,60℃反应56 min时,游离脂肪酸的转化率可达82%左右.结论：用固定床可从PODD连续制备脂肪酸甲酯.     

基于局部纹理描述算子的手掌静脉身份识别

由于手掌生理结构特性和采集环境因素影响,手掌静脉识别系统中所获取图像容易出现噪声过大、光照不均匀等现象,导致识别性能降低.为了解决这一实际问题,提出一种基于局部纹理描述算子的掌脉识别方法.首先使用Gamma校正、DoG滤波、对比度均衡等手段对掌脉图像进行预处理,降低光照影响.然后将掌脉图像分成互不重叠的区块,使用局部三值模式(LTP)提取每一小块的纹理特征,并加以融合,最后利用卡方距离进行匹配识别.在香港理工大学接触式掌脉图库和自建的非接触式掌脉图库上进行实验测试,结果表明,当图像分块大小为16×16像素时,本方法获得了最高的正确识别率,分别为99.981 6％,99.299 4％,优于其他典型方法,提升了掌脉识别系统的性能,增强了系统的鲁棒性,具有实际应用价值.     

基于掌上电脑及智能手机的切削数据库应用技术研究

当今计算机技术应用于机械加工领域已产生了巨大的经济效益和社会效益。切削工艺数据库就是计算机技术与机械加工技术相结合的高技术产物,它将简单的、经验的数据上升为具有科学意义的数据,并应用数据库技术科学地管理切削数据。掌上电脑及智能手机与台式机和笔记本电脑相比,具有体积小、重量轻、价格低及便于携带的优势,是使切削工艺数据库走向实用化的重要手段。本文介绍开发掌上电脑及智能手机用切削工艺数据库的若干技术,包括掌上电脑及智能手机开发环境的建立、微机与掌上电脑和智能手机之间的连接和数据的转换、以及应用情况等。     

煎炸过程对棕榈油品质及南美白对虾中 AGEs含量的影响

以煎炸油和煎炸南美白对虾为研究对象,探究煎炸时间及煎炸物料对煎炸油品质的影响;采用液相色谱-质谱联用及荧光技术测定煎炸对虾中晚期糖基化终末产物（AGEs）的含量,探究煎炸过程对煎炸对虾中AGEs生成的影响。结果表明,高温煎炸可加速棕榈油氧化,使其酸值（AV）、p-茴香胺值（p-AnV）、羰基值（CV）显著增加,24 h时达到最大值。煎炸后,对虾水分含量显著降低,脂肪、丙二醛和荧光AGEs含量显著升高,煎炸批次对其无显著影响。煎炸对虾外层丙二醛、荧光AGEs、非荧光AGEs（羧甲基赖氨酸（CML）、羧乙基赖氨酸（CEL）和甲基乙二醛氢咪唑酮（MG-H1））含量显著高于内部,与未煎炸生虾相比除内部CEL含量有所降低外其余均高于未煎炸生虾。随着煎炸批次的增加,煎炸对虾外层CML、CEL和MG-H1含量均逐渐降低,在煎炸第5批时趋于稳定,煎炸第1批时取得最大值,分别为25.37、335.68 mg/kg和468.20 mg/kg,分别为未煎炸生虾的7、4.5倍和16.5倍;煎炸对虾内部CML、CEL和MG-H1含量均先升高后降低,在煎炸第5批时趋于稳定,煎炸第3批时取得最大值,分别为12.56、85.27 mg/kg和204.20 mg/kg,分别为未煎炸生虾的3.5、1倍和7倍。     

The characteristics of waste-cooking palm biodiesel-fueled CRDI diesel engines: Effect hydrogen enrichment and nanoparticle addition

The influence of iron nanoparticle (INP) addition (75 ppm) and hydrogen enrichment (10 lpm) with waste cooking palm biodiesel blend (WCB) on a CRDI diesel engine is evaluated. A blend of 20% WCB and 80% diesel is used, and the dosing level of INP has been kept at 75 ppm, which has been decided based on the oxygen content of biodiesel. Results indicate that the combination of H₂ enrichment and INP addition improves the BTE and BSFC of biodiesel blends as that of diesel. A maximum improvement of BTE of 7.1% than that of diesel is obtained at 90% loading. The combined impact of better hydrogen combustion characteristics and improved air-fuel mixing with nanoparticles reduces CO and HC emissions by 37.5% and 41.8%, respectively, for the WCB fuel sample. However, NO_X emission shows an elevation of 27.4% compared to diesel. Combustion parameters, namely ICP (80.1 bar) and HRR (89.5 J/˚CA) indicate an improvement of 5.3% and 6.7% compared to diesel for WCB + INP + H₂. This is owing to the combination of hydrogen's rapid flame speed and INP-added biodiesel's increased thermal conductivity.     

Investigation of optimum H2 production from date palm waste leaves using different modeling tools

Globally, the productive utilization of biomass has paid serious attention to fulfilling the energy requirements laid out by the international standards, as to reduce related carbon footprints. Therefore, this study investigates date palm waste leaves which aims to produce environment friendly H₂ gas using gasification technology. The results of 25 experimental runs exhibited that the higher H₂ produced at higher temperature which was mainly supported by water-gas-shift and steam-methane reforming reactions. H₂ prediction was modeled using response surface methodology (RSM) and artificial neural network (ANN). The RSM model exhibited a strong interaction with the regression coefficient (R²) and p-value of 0.89 and 0.000000, respectively. ANN data was disseminated thru K-fold contrivance with back-propagation algorithm. Hence, the training (80% data) and validation (20% data) datasets were found with R² and root mean squared error (RSME) of 0.90 and 0.28, and 0.86 and 0.39, respectively. Kinetics of the process estimated the activation energies (Ea) using Ozawa-Flynn-Wall (OFW), Starink (STK), and Kissinger-Akahira-Sunose (KAS) models. Hence, the values of Ea and R² at conversion degrees (α) 0.1 to 0.8 were ranged between 129.40 and 326.64 kJ/mol and 0.92 to 0.97, respectively. Optimum H₂ production of 49.03 vol% (with LHV of 11.10 MJ/Nm³) was produced. This finding is thought to be a better source of energy which can be an appropriate fuel for Fischer Tropsch process for manufacturing of transportation fuels.     

Effect of hydrogen enrichment and TiO2 nanoparticles on waste cooking palm biodiesel run CRDI engine

In this study, we deal with the production and utilization of waste-cooking palm biodiesel (WCB) and.evaluated the influence of the addition of titanium dioxide (TiO₂) nanoparticles in hydrogen-enriched single-cylinder CRDI diesel engine. XRD, SEM, and EDX decide the structure and morphology of TiO₂ nanoparticles. The TiO₂ nanoparticles were dispersed in the tested fuels at a dosage of 50–75 ppm with the aid of ultra-sonication. Based on the oxidation stability study, the B20 + 75 ppm (TiO₂) fuel blend is the pilot fuel for the engine test. Further, the engine is enriched with a hydrogen (H₂) flow of 10 lpm. Results revealed that the performance parameters were improved with the addition of H₂ enrichment and TiO₂ nanoparticles compared to D. The brake thermal efficiency of the engine was improved by 8.21%. In comparison, brake-specific fuel consumption decreased by 42.86%. Furthermore, adding nanoparticles also reduced CO and HC emissions by 74% and 27.27%, respectively, whereas the NO_x emission was slightly increased. Thus, the findings demonstrated that hydrogen-enriched nanoparticles added to biodiesel might be considered a substitute for fossil fuels and report a positive impact on diesel engine performance without requiring significant modifications.     

Formulation Optimization of a Palm-Based Nanoemulsion System Containing Levodopa

Response surface methodology (RSM) was utilized to investigate the influence of the main emulsion composition; mixture of palm and medium-chain triglyceride (MCT) oil (6%–12% w/w), lecithin (1%–3% w/w), and Cremophor EL (0.5%–1.5% w/w) as well as the preparation method; addition rate (2–20 mL/min), on the physicochemical properties of palm-based nanoemulsions. The response variables were the three main emulsion properties; particle size, zeta potential and polydispersity index. Optimization of the four independent variables was carried out to obtain an optimum level palm-based nanoemulsion with desirable characteristics. The response surface analysis showed that the variation in the three responses could be depicted as a quadratic function of the main composition of the emulsion and the preparation method. The experimental data could be fitted sufficiently well into a second-order polynomial model. The optimized formulation was stable for six months at 4 °C.     

Juice from king palm (Archontophoenix alexandrae) leaf sheathes: chemical characterisation and use in soft drink formulation

The heart of palm is a food extracted from several species of palm trees. Only 10–20% of the raw material is transformed into canned hearts of palm, therefore this agro‐industry generates a large quantity of solid residue. The aim of this work was to extract and characterise a juice produced from this solid residue. This extract is compared with the traditional fruit juices (orange and pineapple juices), obtaining higher contents of minerals, such as magnesium (22.80 mg/100 g) and potassium (276.90 mg/100 g), phenolic compounds (gallic, 3,4‐dihydroxybenzoic, chlorogenic, syringic and caffeic acids) and high free radical scavenging capacity (expressed as 2,2‐diphenyl‐1‐picrylhydrazyl), which suggest high antioxidant activity. Additionally, a new soft drink was formulated using this king palm juice as its main ingredient. The soft drink samples formulated with this juice had high sensory acceptability and high intention of consumption, which suggests an important and low‐cost application for this industrial residue.