脱水马兰加工特性的研究

通过在不同风温（52℃、56℃、60℃）和不同微波输出功率（150W、225W和300W）条件下对马兰进行脱水干燥试验，结果表明，热风干燥时间较长，效率较低，微波干燥随着输出功率的提高干燥率也相应增加，利用微波干燥可以从热风干燥可以从热风干燥所需的200－400min缩短到5－8min，同时，微波干燥能更好地保持马兰的色泽，并有更高的复水性。     

脱水皮蛋颗粒加工工艺研究

以新鲜皮蛋为主要原料,采用麦芽糊精混合液进行预处理,经过热风干燥加工脱水皮蛋颗粒。以复水比与复原率为考察指标,通过L9(34)正交实验得出上佳预处理工艺:加入10%(w/v)麦芽糊精、20%(w/v)蔗糖与10%(w/v)食盐混合液室温浸泡30min。在热风干燥工艺研究中,以复水比、复原率、色泽以及干燥时间等指标按不同权重对脱水皮蛋颗粒品质进行评分,得出风温度为60℃时干燥效果较好;同时,对不同温度条件下皮蛋颗粒的质量变化进行动态测定,并绘制了相应的干燥曲线。     

大蒜干制品的加工与出口

大蒜为百合科葱属植物，其嫩苗、花茎和鳞茎等均可食用。大蒜含丰富的蒜氨酸，它在蒜氨酸酶的作用下，形成一种挥发性含硫化合物即大蒜素，具有特殊的辛辣味，有增进食欲和抑菌、杀菌作用。我国是大蒜种植面积和产量最多的国家之一。由于其含丰富的营养及独特的食疗功效，所以愈来愈受人们的青睐和重视。近几年来已有不少大蒜加工品出口，其市场潜力很大。     

真空微波与热风联合干燥蒜片的工艺研究

运用正交实验对四种无硫护色液进行复合实验,最佳护色组合为：CaCl2浓度为0.6%、NaCl浓度为0.8%、L-半胱氨酸浓度为0.10%,经此复合护色液护色得到干燥蒜片L＊值为86.23。比较了热风、真空微波、真空微波与热风联合干燥三种生产工艺所得蒜片干制产品的品质,采用正交实验优化了热风与真空微波联合干燥蒜片的生产工艺。结果表明：前期采用真空度-90kPa,微波功率375W,微波干燥20min,后期60℃热风干燥60min,干燥总时间为80min,缩短了热风干燥时间,得到了高品质的蒜片产品。     

真空微波与热风联合干燥蒜片的工艺研究

运用正交实验对四种无硫护色液进行复合实验,最佳护色组合为:CaCl2浓度为0.6%、NaCl浓度为0.8%、L-半胱氨酸浓度为0.10%,经此复合护色液护色得到干燥蒜片L*值为86.23。比较了热风、真空微波、真空微波与热风联合干燥三种生产工艺所得蒜片干制产品的品质,采用正交实验优化了热风与真空微波联合干燥蒜片的生产工艺。结果表明:前期采用真空度-90kPa,微波功率375W,微波干燥20min,后期60℃热风干燥60min,干燥总时间为80min,缩短了热风干燥时间,得到了高品质的蒜片产品。      

渗透预脱水后的樱桃番茄干燥工艺优化

该文以"苏龙一号"樱桃番茄品种作为试材,首先对其进行渗透预脱水处理,然后系统研究了热风干燥、微波干燥和真空干燥对樱桃番茄干燥特性和品质的影响。将样品干燥至水分含量为(20±1)%,微波干燥所需时间短,能耗低,但干燥后可溶性糖和番茄红素含量显著低于热风和真空干燥后的样品;真空干燥后样品可溶性糖和番茄红素含量与热风干燥的样品无显著性差异,但真空干燥达到相同干燥效果相对于热风干燥耗时长。实验确定渗透预脱水后樱桃番茄的合适干燥方式为60℃热风干燥,此条件下,营养成分损失相对较少,色泽佳,能耗低。     

脱水马兰加工特性的研究

通过在不同风温(52、56和60℃)和不同微波输出功率(150、225、和300W)条件下对马兰进行脱水干燥试验,结果表明:热风干燥时间较长,效率较低,微波干燥随着输出功率的提高干燥速率也相应增加。利用微波干燥可以从热风干燥所需的200～400min缩短到5～8min,同时,微波干燥能更好地保持马兰的色泽,并有更高的复水性。     

脱水茭白加工工艺研究

利用微波能结合热风干燥对茭白脱水的工艺进行了初步研究。茭白切片厚度为4mm,经微波杀青,用浓度0.01%EDTA、0.1%柠檬酸、0.02%焦亚硫酸钠配成的护色液护色3h,65℃鼓风干燥1.5h处理后微波干燥,能得到色泽度、外观质地较好而均匀的微波脱水茭白产品。     

番木瓜片热风微波耦合干燥条件及干燥模型建立

为研究番木瓜片采用热风微波耦合干燥的干燥特性和最优工艺组合,选用自制热风微波耦合干燥系统进行实验,得出热风微波耦合干燥曲线、干燥速率曲线及最优工艺组合,并建立干燥模型。结果表明:番木瓜片热风微波耦合干燥速率经历一个短暂的加速期后较长时间处于降速期;番木瓜片热风微波耦合干燥综合效果最优的组合为:热风温度60℃、微波功率密度5.5 W/g、热风风速0.5 m/s,其中微波功率密度对干燥综合效果的影响起主导作用;番木瓜片热风微波耦合干燥动力学模型可用Page方程描述,即M_R=exp(-0.0011T-0.0069P_D+0.073t(^{0.0015T2-0.1993T+7.9642});番木瓜片热风微波耦合干燥有效水分扩散系数介于2.533×10^-96.0792×10^-9m²/s之间,且有效水分扩散模型为:10^-10D_eff=0.507T+6.72P_D+10.1v-32。      

Effect of temperature cycling on allinase activity in garlic

Allinase, which catalyzes the conversion of alliin to allicin, the principal component of potential medicinal value in garlic, is a thermo-labile enzyme. The potential for allicin formation is determined by the quantity of allinase that remains active after the process of preserving garlic by drying. The kinetics of enzymatic activity loss during drying by temperature cycling or by constant temperature were evaluated and compared. Allicin-forming potential was 91% preserved by temperature cycling from 40 to 60 °C. It was found that sugars present in the garlic and the high molecular mass of the enzyme were responsible for protection against degradation at high drying temperatures. Preservation of the enzymatic activity under cyclical conditions occurred mainly with exposure to low temperatures for drying periods longer than those of constant drying conditions.     

QuEChERS-气相色谱-三重四极杆质谱法测定大蒜中3种农药残留

目的 建立QuEChERS前处理结合气相色谱-三重四极杆串联质谱联用法测定大蒜中敌百虫、霜霉威和氯氟氰菊酯共3种农药残留的分析方法.方法 将大蒜捣碎,用乙腈-醋酸(99:1,V:V)、无水硫酸镁、醋酸钠和陶瓷均质子提取,经无水硫酸镁和乙二胺-N-丙基甲硅烷(ethylenediamine-N-propylsilane,...     

Optimisation of the pulsed vacuum osmotic dehydration of cladodes of fodder palm

Fodder palm, a great source of nutrients for human and animals, grows even in arid climates. Pulsed vacuum osmotic dehydration is an efficient process for obtaining semidehydrated food. It was used to slice cladodes of fodder palm. The independent variables used were temperature (30–50 °C), pulsed vacuum pressure (50–150 mbar) and NaCl concentration (5–15 g per 100 g solution). The response variables were water activity (a_w), moisture content (X), colour parameters, water loss (WL), solid gain (SG) and weight reduction (WR). The pulsed vacuum osmotic dehydration process was optimised for minimum values of a_w, X and SG, and maximum values of chroma. The experimental data obtained with the optimum condition (100 mbar; 10 gNaCl per 100 g solution, 44 °C) were near the estimated ones. For example, WL, a_w and ?E, and their error were 8.15 g per 100 g, 11%; 0.985, 0.3% and 6.15, 15.2%, respectively.     

Drying of plums (Prunus sp,c.v Gulfblaze) treated with KCl in the field and subjected to pulsed vacuum osmotic dehydration

The pulsed vacuum osmotic dehydration (PVOD) promotes more homogeneous concentration profiles in the product and quality improvement of several fruits. The objective of this work was to study the drying of plums submitted to treatments of plants manure with KCl and PVOD (5” c.a., 10 min). Experimental planning was done with the following independent variables: doses of KCl (400, 700 and 1000 g/plant), concentration of sucrose solution (40; 50 and 60 ºBrix) and drying temperature (50, 60 and 70C). The tested variables were: color, shrinkage, visual quality and rehydration. Temperature leads to a skin browning at fruit pulps and lower visual quality. The treatment with KCl leads to final products with lower moisture content. The higher the values of all the independent variables, the lower the shrinkage and the rehydration capacity. Plums submitted to convective drying with previous PVOD promote a new product with good visual quality and satisfactory shrinkage.     

Fluidized-bed drying as a feasible method for dehydration of Enterococcus faecium M74

The suitability of fluidized-bed technology for the dehydration of probiotic Enterococcus faecium M74 was evaluated. Fluidized-bed drying was processed by layering the microorganisms on spherical pellets. The impact on cell viability of atomizing air pressure, processing temperature and time was investigated. Using 1.5 bar atomizing air pressure, 37 °C processing temperature, and 15 min processing time provided optimal dehydration condition. Changing these values resulted in excessive stress on the cells and affected the cell viability. Next, we compared the impact on cell viability of fluidized-bed drying with that of freeze-drying. Fluidized-bed drying caused more substantial losses of cell viability. However, viability of cells pre-treated with membrane protective agents such as sucrose or skim milk was less affected by fluidized-bed drying than by freeze-drying, resulted in a minor degree of membrane damage after 2 months storage. Comparison of the flow characteristics of freeze-dried cells and fluidized-bed dried cells layered on spherical pellets showed the superior flowability of the latter.     

大蒜抑菌效果研究及与生姜的比较

研究了大蒜和大蒜油对不同细菌的抑菌作用及与生姜的比较,并进行了大蒜和生姜对辣椒的抑霉试验,以期将它们应用于食品的防腐保鲜。大蒜油的制备采用乙醇浸提法,抑菌试验采用滤纸片法。结果显示大蒜的抑菌效果以大肠杆菌最为显著。而生姜则对链球菌的抑菌效果较为明显。总体抑菌效果比较,大蒜对细菌和霉菌的抑制效果优于生姜。     

The production of pork with garlic flavour notes using garlic essential oil

Garlic essential oil (GEO) added directly to pork mince or to the diet of pigs was evaluated for its effectiveness in masking undesirable mutton flavour. Pork was from 31 female pigs (Duroc × (Large White × Landrace)) grown on diets containing either animal-plus-plant products (AP diet) or plant products only (P diet) with four levels of GEO: 0, 0.55, 1.44 and 1.84 g/kg feed and 0, 0.55, 1.44 and 2.15 g/kg feed in the AP and P diet, respectively. Garlic flavour increased and mutton flavour decreased in pork from pigs that consumed more than about 150 g and 220 g of GEO in P and AP diets, respectively over the 57-day feeding period. The garlic flavour was stronger and the mutton flavour less intense for pork from pigs on the P diet. When GEO was added to pork mince at 125 ppm, it significantly reduced mutton flavour.     

探讨干燥方法对方便米饭品质的影响

本文主要研究了热风干燥,微波干燥和真空冷冻干燥三种干燥方法对方便米饭复水时间、复水率、碘兰值、酶解率、米汤吸光率等品质的影响及比较。结果表明,真空冷冻干燥所得到的方便米饭品质优于另外两种方法,复水时间只需要5.0min,复水率达到3.50,其他理化指标也同样显示出其优越性。