漂烫对速冻薯条品质及淀粉糊化度的影响研究

研究以夏波蒂为原料,利用两种漂烫工艺制备速冻薯条,采用感官评价评定薯条品质。为获得高品质的薯条,首先测定鲜薯的理化成分(水分、淀粉、还原糖);其次探究预热、漂烫工艺对薯条淀粉糊化度的影响;最后测定不同漂烫工艺下漂烫水的糖度。以薯条品质、淀粉糊化度及漂烫水糖度为评价指标,对漂烫工艺进行参数优化,得到最佳的漂烫工艺参数:85℃漂烫6 min而后75℃漂烫20 min。在此条件下薯条淀粉完全糊化,薯条炸后的感官评分高达95。研究结果表明:漂烫工艺对薯条品质有影响;随着漂烫时间和温度的增加,薯条的糊化度增大,漂烫水的糖度升高;高温短时与低温长时相结合的两步漂烫工艺更合理,该研究结果为薯条漂烫工艺的研究提供理论依据和技术支持。     

蕨菜速冻前预处理工艺的实验研究

就蕨菜冻结前预处理工艺(漂烫和添加剂处理)进行了研究,分析了漂烫时间、温度及添加剂种类、浓度对速冻原料的影响,得出了漂烫工艺的最优参数。     

芦荟凝胶粉制备过程中多糖变化研究

本文采用真空冷冻干燥技术制备芦荟凝胶粉,重点研究工艺中漂烫去皮的漂烫时间、漂烫温度等因素对芦荟多糖含量的影响,并对天然澄清剂对芦荟多糖含量的影响进行分析。结果表明:多糖含量随着漂烫时间和漂烫温度的增加而相应升高,其中漂烫温度对芦荟多糖相对含量的影响更为显著,比较理想的制备工艺为漂烫时间6min,漂烫温度85℃;天然澄清剂对芦荟多糖也有絮凝能力,从而导致芦荟多糖含量下降。     

胡萝卜、油菜的通电加热烫漂研究

研究了通电加热烫漂对胡萝卜、油菜中维生素含量的影响,并与普通电炉加热进行了比较;研究了胡萝卜、油菜通电加热烫漂的最佳工艺条件。实验证明,随着烫漂时间的延长,胡萝卜中的β-胡萝卜素含量明显降低,油菜中VC的含量也明显降低;通电加热烫漂后的维生素含量明显高于电炉加热;而胡萝卜通电加热的最佳烫漂工艺为,烫漂时间3 min,颗粒尺寸10 mm,料液比(g:mL)1∶4,电压220 V;油菜通电加热烫漂的适宜工艺条件为料液比(g:mL)1∶4,烫漂时间0.5 min,电压220 V。     

香菇速冻前漂烫预处理工艺优化研究

本文旨在建立最大限度地保持香菇微观质构的速冻前预处理工艺.采用响应面方法研宛香菇的漂烫温度和时间对香菇品质的影响.通过中心优化组合设计得出速冻香菇最佳预处理工艺为:漂烫温度93.61℃、瀑烫时间2.32min.香菇经此漂烫预处理工艺,并于-35℃冻结7 min,解冻后透射电镜结果显示香菇微观质构良好.建立了漂烫温度、漂烫时间与过氧化物酶酶活相关性的数学模型,可充分预测瀑烫预处理对过氧化物酶酶活的影响.     

漂烫对速冻苹果质地的影响

采用质地多面分析（TPA）试验方法,研究了速冻苹果不同漂烫过程中的漂烫时间、漂烫温度、料液比对质地的影响,并对其过氧化物酶（POD）活性、感官品质的变化以及其硬度、内聚性、回复性、弹性和咀嚼性等相关性进行了研究。结果表明,漂烫对速冻苹果质地有显著影响,适度漂烫在其速冻加工中至关重要,最佳漂烫工艺为漂烫时间4～5 min、漂烫温度87～92 ℃,料液比为1∶10～1∶12（g∶mL）。     

养心菜漂烫工艺的研究

对不同漂烫条件下养心菜过氧化物酶活性、色泽、质构、齐墩果酸含量的变化情况进行了分析,并通过单因素实验考察漂烫温度、时间以及养心菜切分长度3个因素对VC含量的影响,再结合上述各项指标的变化情况选取因素水平。最后,通过Box-Benhnken的中心组合实验设计和响应面分析优化养心菜漂烫工艺,以VC保留率为响应值进行分析。实验结果表明:漂烫工艺的最优参数组合为:漂烫温度90℃、漂烫时间60s、切分长度8cm,在该工艺条件下进行实验,得到的养心菜VC保留率为80.01%。     

微波烫漂与热水烫漂毛豆仁风味成分比较

选取苏ZY01 和苏ZY02 两个毛豆品种,采用微波烫漂方法和热水烫漂进行处理,用GC-MS 分析并比较经响应曲面优化的较佳微波烫漂工艺和传统的热水烫漂工艺条件对毛豆仁挥发性风味成分的影响。结果显示：1- 辛烯-3- 醇、异戊醛、2- 癸烯醛、2- 庚烯醛、戊醛、1- 辛烯-3- 酮、3- 辛酮、己醛、己醇等对毛豆仁产生重要影响的化合物在优化的微波烫漂中均比热水烫漂保存好,表明微波烫漂对毛豆仁风味形成贡献较大。     

绿芦笋真空干燥工艺研究

主要研究了绿芦笋的真空干燥工艺条件,以漂烫温度、漂烫时间、干燥温度和工作压力为因素,通过L16(45)正交试验,确定漂烫和真空干燥的最佳工艺条件为85℃热水中漂烫4min、干燥温度为75℃、工作压力为0.03MPa。     

超声和烫漂预处理对红薯叶热风干燥的影响

采用超声、烫漂两种方式对红薯叶进行热风干燥前的预处理,研究超声时间、超声功率、超声温度和烫漂时间、烫漂液ZnAc_2与EDTA-2Na质量比、烫漂温度对红薯叶热风干燥后叶绿素、复水性、色差、干燥特性、能耗以及微观结构的影响。结果表明:超声处理的最佳工艺为超声时间10min、超声功率300W、超声温度40℃,经超声预处理的红薯叶干燥效率较高,皱缩率低,组织结构较为完整;烫漂处理的最佳工艺为烫漂时间60s、烫漂液ZnAc_2与EDTA-2Na质量比2:1、烫漂温度80℃,经护色液烫漂处理干燥后的红薯叶复水率、叶绿素含量和色泽都稍高,质构紧密均匀,细胞开孔率高,总能耗低。     

新型果蔬漂烫技术研究进展

果蔬水分含量较高,不易贮藏,采后腐烂变质情况较为严重。干燥可以有效延长果蔬的贮藏期,是果蔬加工常用的方法之一。漂烫是果蔬干燥前的关键步骤,具有灭酶、护色的作用。传统的漂烫方法采用高温热水及蒸汽进行灭酶,对果蔬品质影响较大。近年来科学家们提出并研究了一些新型漂烫技术。本文主要针对在传统漂烫方法基础上改进的一些新技术(超高温瞬时蒸汽漂烫和超声波辅助热漂烫)和新型干法漂烫技术(远红外漂烫、欧姆漂烫、微波漂烫以及射频漂烫),重点介绍其技术原理和应用优势。新型漂烫可提高漂烫效率,其中干法漂烫不采用水为加热介质,水溶性营养物质损失较少,产品品质较好,在工业上应用可降低能耗并减少废水的产生,具有良好的应用前景。本文为后续研究新型果蔬漂烫技术以及开发新型联合干燥技术提供参考。     

Effect of different types of blanching on the colour of sliced carrots

Sliced carrots were blanched by four methods—hot water blanching, in-can steam blanching, direct steam blanching and microwave blanching. The colour observed by the Lovibond Tintometer changed from red to yellow. The Harrison colorimeter measurements of a more, objective nature indicated that the blanched carrots became more light and more saturated. Similar colour changes were exhibited by all four blanching procedures. The change in colour was attributed to changes in the ultra-structure of carrots, especially in the chromoplast. When hot water blanching was used, there was some loss of carotene in the blanching media.     

Effects of Microwave, Steam and Water Blanching on Freeze-Dried Spinach

Microwave energy was demonstrated to be a convenient and effective method of blanching. Compared to steam or water, microwave blanching was superior in retention of ascorbic acid. The texture of rehydrated, microwave blanched spinach was firm, chewy and highly acceptable. Water blanching ruptured the cells and destroyed fine cellular structure as compared to steam blanching which caused less cellular disruption and greater retention of tissue structure. Microwave blanching resulted in coagulated protoplasmic material surrounding the cell walls. Cell and tissue structure remained intact which resulted in h gh rehydration ratios and acceptable textural characteristics. Microwave blanching yielded a superior freezedried product as compared to water and steam blanching.     

不同预处理方式对花椰菜干制品品质影响研究

为筛选适宜花椰菜干制的预处理方法,本研究通过采用沸水烫漂、蒸汽烫漂、微波加热和超声波辅助烫漂4种不同预处理方式处理新鲜花椰菜,考察干燥后其干制品收缩率、复水比、色泽、V_C、总黄酮、总酚及总硫代葡萄糖苷含量等感官和营养指标的变化情况。结果表明:不同预处理方式处理后花椰菜干燥时间均有缩短,其中沸水烫漂、蒸汽烫漂和微波加热较未处理缩短了18.18%,而超声波辅助烫漂处理后缩短了27.27%。微波加热和超声波辅助烫漂处理后花椰菜干制品的色泽变化较小,超声波辅助烫漂收缩率最小,为67.41%,微波加热复水能力较强,为3.77。不同预处理方式对花椰菜干制品营养成分影响不同,与未处理样品相比,不同烫漂方式处理后还原糖损失率为8.85%~23.96%、总糖损失率为3.74%~39.35%。微波加热花椰菜干制品可溶性蛋白和总硫代葡萄糖苷保留率分别为81.80%和31.93%,超声波辅助烫漂后花椰菜干制品V_C、总黄酮和总酚保留率分别为40.18%、83.70%和38.40%。综合比较表明:超声波辅助烫漂后花椰菜干制品感官及营养品质最佳。     

Vacuum-steam pulsed blanching (VSPB) softens texture and enhances drying rate of carrot by altering cellular structure,pectin polysaccharides and water state

As a new type of blanching technology, vacuum-steam pulsed blanching (VSPB) has higher blanching efficiency and quality, but the mechanism of this technology on texture softening and drying enhancement is still unclear. In this study, the mechanism was revealed from texture, pectin, nanostructure, cell ultrastructure, calcium, and water state. Results revealed that VSPB treatment reduced the hardness and chewiness, increased water-soluble pectin, decreased sodium‑carbonate-soluble and chelate-soluble pectin concentration, and resulted in depolymerization and degradation of pectin nanostructure. However, transmission electron microscopy showed that blanching damaged the cell wall structure and the integrity of the middle layer. Scanning electron microscope - Energy dispersive X-ray spectroscopy measurement observations indicated that lipid droplets containing calcium ions were formed under the action of VSPB. In addition, low field nuclear magnetic resonance showed that the redistribution of moisture in carrot was facilitated by VSPB. The findings reveal the mechanism of texture softening and drying rate enhancement driven by blanching.Industrial relevanceThermal blanching is an essential thermal treatment for many fruits and vegetables processing. Hot water blanching and steam blanching are the two most frequently employed blanching methods due to simple to establish and easy to operate. However, hot water and steam blanching holds several disadvantages, e.g., hot water blanching requires a huge amount of water and generates an excessive amount of wastewater, particularly loss of water-soluble nutrients during blanching due to leaching and diffusion, while for steam blanching, the existence of air and water vapor among the piled materials leads to low blanching efficiency and un-uniform heating. VSPB is an innovative steam blanching method. In the VBSP process, the air and water vapor are expelled by the vacuum pump to facilitate steam deep penetration in the materials, particularly the piled materials, so as to improve blanching efficiency and uniformity. Previous study indicated VSPB could soften texture and reduce the drying time of carrot, but the mechanism was not clear. The current work reveal that VSPB softens texture and enhances drying rate of carrot via micro-, ultra-structure modification, pectin polysaccharides degradation and changes of water state. The findings have important implications for understanding and controlling the blanching triggered texture formation and drying enhancement.     

不同护色预处理对牛蒡片真空冷冻干燥特性的影响

研究护色预处理方式对牛蒡片真空冷冻干燥特性的影响,采用复合护色液、热烫、超声波-热烫3种护色处理方式,并进行真空冷冻干燥对比实验和分析。结果表明:超声波-热烫组冻干耗时12.20 h,分别比护色液、热烫组缩短冻干时间15.86%、6.87%(P0.05);超声波-热烫组冻干牛蒡片复水比最高,为5.52 g/g,分别高出护色液、热烫组复水比18.71%、12.42%(P0.05);护色液组冻干牛蒡片体积皱缩比最大,为0.93,稍高于热烫、超声波-热烫组体积皱缩比(P0.05);护色液组冻干牛蒡片硬度最高,为54.32 N,分别高于热烫、超声波-热烫组硬度90.53%、120.73%(P0.05);护色液组冻干牛蒡片色泽变化ΔE最小,其次为超声波-热烫组,热烫组ΔE最大;护色液组冻干牛蒡片复水后ΔE显著高于热烫、超声波-热烫组(P0.05);扫描电子显微镜观察分析表明,热烫、超声波-热烫组细胞轮廓形态产生皱缩、卷曲现象比护色液组更明显;低场核磁共振分析表明,超声波-热烫组、热烫组冻干片横向弛豫时间T2图谱相对于护色液组呈现不同程度右移趋势,冻干牛蒡片残留水分自由度增加、束缚作用变小。     

热烫处理对南瓜叶化学成分及色泽的影响

为探明热烫处理过程中南瓜叶的品质变化,研究了蒸汽热烫、微波热烫及热水热烫对南瓜叶中VC、可溶性蛋白、叶绿素及草酸含量、过氧化物酶（peroxidase,POD）活性及色泽的影响。结果表明：3 种热烫方法对南瓜叶POD活性均有明显的抑制作用,蒸汽热烫可在60 s内使POD残余酶活力降低至7.10%,热水热烫对POD活性的抑制作用受温度影响较大,在95 ℃以上即对POD活性有明显抑制作用,此温度条件下热烫60 s,POD残余酶活力可降至4.85%;于微波功率480 W条件下热烫50 s,南瓜叶POD残余酶活力降至5.05%;经热水热烫的南瓜叶VC、可溶性蛋白含量最高,其次是微波烫漂,蒸汽热烫的最低;热水热烫的南瓜叶草酸含量亦较低,且L*值最大而a*值最小,即热水热烫的南瓜叶色泽最优。热水热烫是南瓜叶最适宜的热烫方式,其最适宜的烫漂条件为95 ℃、60 s。     

速冻蔬菜热烫处理的优化和节能

大多数速冻蔬菜必须经过热汤处理以保证其在冻藏期间质量的稳定性。但是热烫易引起蔬菜的色、香、味和质地的变化。目前蔬菜的热烫终点以过氧化物酶作为指示剂来确定。有关研究表明，以过氧化物酶的指示剂会导致某些蔬菜热烫过度，因此必须寻找对这蔬菜更合适的酶作为指示剂，以便优化热烫处理。在速冻蔬菜的热烫过程中要消耗大量的能量 和水，有一种热烫－冷却组合器可较好地解决蔬菜热烫过程的节能、节水问题。     

不同烫漂时间对真空油炸毛豆仁品质的影响

对生产中不同烫漂时间对真空油炸毛豆仁品质的影响进行了研究。实验结果表明,烫漂时间的长短(在0-10min内)对真空油炸毛豆仁的脆度、瓣的完整性以及色泽有明显影响,综合比较2-10min处理后产品的Vc含量和蛋白质含量,烫漂时间的长短对产品的营养物质损耗不是很大,烫漂时间对含油率影响较大,超过6min后,含油率下降不是很明显。综合比较表明,烫漂时间6min为最佳。