不同干燥方式对槐花蛋白加工特性及抗氧化性能的影响

实验考察了槐花蛋白在冷冻干燥、真空干燥、微波真空干燥及热风干燥4种干燥方式下蛋白质的乳化性、持水性、起泡性、黏度、热凝集性及抗氧化性的变化。结果表明:冷冻干燥条件下槐花蛋白的乳化性、乳化稳定性、起泡性、热凝集性最好,微波真空干燥在蛋白质的泡沫稳定性、持水性和羟基自由基清除能力方面最好,真空干燥条件下蛋白质黏度、脂质过氧化物自由基抑制率最好。综合各项指标,根据经济合理的原则,选用微波真空干燥能较好地保存槐花蛋白质的加工性能及抗氧化活性。     

载能微波在不同负压水平的干燥模式与应用

为回顾近年来载能微波在农产品干燥中的研究进展,并解析负压环境对干燥行为的影响,文章以微波干燥的负压水平和干燥模式为主线,阐述高水分农产品物料在低真空度的负压微波脉冲喷动干燥(pulse-spouted microwave vacuum drying,PS-MVD),中真空度的微波真空干燥(microwave vacuum drying,MVD),高真空度的微波真空冷冻干燥(microwave vacuum freeze drying,MVFD)的干燥模式及物料特性,同时对农产品物料“热风-微波真空”组合干燥、“微波真空-真空含浸”加工、“脉冲喷动微波真空冷冻干燥”工艺的创新应用展开讨论。     

不同干燥方法对花生蛋白功能特性的影响

以花生蛋白为原料,分别采用热风干燥、真空干燥、微波干燥和微波结合真空干燥对花生蛋白进行干燥处理,比较不同的干燥方式对花生蛋白功能特性(吸油性、持水性、乳化性、乳化稳定性、起泡性能和起泡稳定性)的影响。实验表明,微波结合真空干燥的花生蛋白不仅干燥时间短,而且具有较好的功能特性,微波结合真空干燥是一种干燥花生蛋白的适宜方法。     

土豆片脉冲喷动微波负压干燥特性及品质

在干燥腔内真空压力范围为11.8~15.0 kPa的条件下,研究微波功率、脉冲喷动频率、预处理及不同组合方式对脉冲喷动微波负压干燥(PSMVD)土豆片的干燥特性及色泽、质构、均匀性等品质的影响。结果表明:Midilli传质薄片模型优于其它三个模型;未漂烫处理及提高微波功率可以增加土豆片在干燥过程中水分扩散系数Deff,从而缩短土豆片脉冲喷动微波负压干燥时间。与传统的干燥相比,脉冲喷动微波负压干燥具有干燥周期短、产品干燥均匀性及品质较好等优点。     

不同干燥方式对橄榄果粉品质的影响

比较微波干燥、热风干燥、真空干燥以及真空冷冻干燥对橄榄果粉外观色泽、物理特性、营养成分及微观结构等品质的影响。结果表明:真空冷冻干燥橄榄果粉色泽较佳,具有较高亮度和最低的红绿度,最接近鲜食橄榄绿色色泽;热风干燥和真空干燥所得果粉吸油性较低,吸湿性较高,热风干燥的果粉堆积密度和溶解度均最高,真空冷冻干燥的果粉堆积密度最低,吸湿率低,复水性、流动性、吸油性和溶解度均较高,微波干燥的果粉含水率最高,复水性、吸湿率、堆积密度、吸油性和溶解度均较低;微波干燥的还原糖、总酸含量损失较小,热风干燥的类黄酮损失较小,真空干燥的总糖和总酚含量损失较小,真空冷冻干燥的蛋白质含量损失较小。扫描电镜观察微观结构发现微波干燥和真空冷冻干燥果粉颗粒间空隙大,组织较光滑完整,皱缩少,热风干燥和真空干燥果粉颗粒间空隙小,部分皱缩。通过主成分分析品质综合得分结果为:真空冷冻干燥>真空干燥>热风干燥>微波干燥。     

不同干燥方式对苦荞蛋白功能性质的影响

以苦荞麦粉为原料,通过碱溶酸沉法提取苦荞麦蛋白,考察不同的干燥方式(真空干燥、热风干燥、微波干燥、冷冻干燥)对苦荞蛋白一系列功能性质的影响。结果表明:干燥方式影响苦荞蛋白性质,经冷冻干燥处理后的苦荞蛋白含量最高(42.95%),且溶解性与乳化性均最好,热风干燥与真空干燥次之,微波干燥效果最差。起泡性实验结果表明,微波干燥起泡能力最差,仅为28%,真空干燥起泡稳定性相对较好(50%)。DSC扫描曲线在80～250℃温度范围内出现2个峰,峰值温度分别在147～155℃与220～223℃,4种干燥方式处理下的苦荞蛋白具有相似的热力学性质,经干燥处理后的苦荞蛋白变性温度升高。实验结果为进一步研究苦荞蛋白在功能食品的应用提供理论基础。     

不同干燥方法对花生蛋白功能特性的影响

以花生蛋白为原料，分别采用热风干燥、真空干燥、微波干燥和微波结合真空干燥对花生蛋白进行干燥处理，比较不同的干燥方式对花生蛋白功能特性（吸油性、持水性、乳化性、乳化稳定性、起泡胜能和起泡稳定性）的影响。实验表明，微波结合真空干燥的花生蛋白不仅干燥时间短，而且具有较好的功能特性，微波结合真空干燥是一种干燥花生蛋白的适宜方法。     

不同干燥工艺对南美白对虾仁品质的影响

以南美白对虾仁为实验原料,研究了热风干燥、微波干燥、热风联合微波喷动干燥和真空冷冻干燥对南美白对虾的影响,并且以干燥速率、复水率、色泽变化、质构以及脂肪氧化等指标进行比较。研究结果表明:真空冷冻干燥得到产品的品质最好,但是干燥时间是热风干燥的2.25倍,是微波干燥和热风联合微波干燥的9倍和10.3倍;热风联合干燥能够克服单一微波干燥的不均匀性,且干燥后样品的品质最接近于真空冷冻干燥,因此热风联合微波喷动干燥是一种具有发展前景的干燥方法。     

不同干燥方式桑叶粉物理特性、氨基酸及挥发性成分分析

对比分析热泵干燥、微波干燥、真空冷冻干燥三种干燥方式对桑叶粉色泽、粉体特性、氨基酸组分及挥发性成分的影响;结果表明真空冷冻干燥L*、b*最大,a*最小;微波干燥润湿性、持水力和持油力最差,溶解性和堆积密度最强;真空冷冻干燥桑叶粉润湿性、吸湿性、持水力和持油力最强,堆积密度最小;微波干燥桑叶粉总氨基酸、必需氨基酸以及必需...     

冷冻预处理及负压微波喷动干燥对脱水牛蒡品质的影响

以牛蒡为主要原料,在干燥腔内真空压力波动范围为12~21 kPa的条件下,研究喷动频率、微波功率,以及预处理方式,对负压微波喷动干燥(PSMVD)牛蒡片的干燥特性及质构、收缩率、复水比、感官评分、色泽等品质的影响。结果表明:喷动频率、微波功率,以及预处理方式对其影响较大,当喷动频率为3.3 r/min,微波功率为19.8 W/g,采用冷冻预处理(-18℃,12 h)的方式,所得到的牛蒡产品色泽佳、质地松脆、风味浓郁、保质期长。     

电渗析脱盐对咸鸭蛋蛋清理化性质的影响

目的：为评估电渗析脱盐是否对鸭蛋清的功能性质和营养性有影响,研究经电渗析脱盐后鸭蛋清的部分理化性质变化。结果：脱盐后鸭蛋清的凝胶硬度在蛋白质量浓度较低时(5～8g/100mL)与鲜鸭蛋清相比无显著差异;当蛋白质量浓度为3～9g/100mL时,脱盐鸭蛋清的乳化活性及起泡性较咸鸭蛋清均有所提高,与鲜鸭蛋清相比,两者乳化活性相当,但其起泡性优于鲜鸭蛋清;SDS-PAGE、DSC及氨基酸分析表明,咸鸭蛋清脱盐前后蛋白质相对分子质量无明显变化;脱盐后的鸭蛋清与鲜鸭蛋清的氨基酸组成、热变性温度及颜色均十分接近。结论：经电渗析脱盐处理,鸭蛋清的理化性质影响不大,可作为良好的食品原辅料。     

喷雾干燥与冷冻干燥鸡蛋粉特性研究

以鲜鸡蛋为原料,利用喷雾干燥和冷冻干燥技术制备鸡蛋粉,对比2种蛋粉水分含量、水分活度、溶解度、色差、微观结构等理化性质,同时检测起泡性、乳化性,并选用喷雾干燥蛋黄粉制备凝胶探讨功能特性。结果表明:喷雾干燥蛋粉和冷冻干燥的蛋粉水分含量、水分活度、溶解度和色差差异显著(P<0.05),且喷雾干燥蛋粉和冷冻干燥蛋粉起泡性及乳化性均在氯化钠浓度为0.5 g/100 mL时达到最大值;制备凝胶最佳条件为加水量为150%、氯化钠浓度为3%、温度100℃、热处理15 min。此项研究将对蛋粉的应用奠定理论基础。     

干燥方式对蛋清蛋白理化性质和功能特性的影响

为探究干燥方式对蛋清蛋白（egg white protein,EWP）功能特性的影响及其内在机理,分别通过喷雾干燥与真空冷冻干燥制备蛋清蛋白粉,并对其蛋白结构、理化性质与功能特性进行研究。结果表明,与蛋清液（EWP-C）相比,喷雾干燥使蛋清蛋白（EWP-P）的内源性荧光强度降低,表面疏水性和表面游离巯基含量增大。傅里叶变换红外光谱分析显示,EWP-P的α-螺旋、β-折叠和β-转角分别为16.30%、25.72%和40.23%,冷冻干燥蛋清蛋白（EWP-D）分别为20.43%、24.32%和35.69%。不同pH下,EWP-D的溶解度均高于EWP-P,表面张力小于EWP-P。此外,EWP-P的接触角为99.62°,高于EWP-D（接触角为65.97°）,表明喷雾干燥能显著提高蛋白的疏水性（P<0.05）。EWP-D在不同pH下的乳化性、乳化稳定性以及起泡性均大于EWP-P,但起泡稳定性更小,这与EWP-D较高的溶解性与较低的表明疏水性有关。荧光倒置显微镜及激光共聚焦扫描显微镜分析表明EWP-D乳液的微粒更小,分布更均匀,其稳定性高于EWP-P。综上,喷雾干燥蛋清蛋白的β-折叠结构较多,表面游离巯基含量和表面疏水性较高,具有较好的凝胶性;冷冻干燥蛋清蛋白的表面疏水性较小,且表面张力小、溶解度大,具有更好的乳化能力与起泡性。     

PICKLING TIME AND ELECTRODIALYSIS AFFECTS FUNCTIONAL PROPERTIES OF SALTED DUCK EGG WHITE

Salted duck egg was prepared by coating fresh duck egg with laterite and sodium chloride. The effects of different lengths of pickling time and electrodialysis desalination on foaming, emulsifying and gelation properties of salted duck egg white (SDEW) were investigated. The pH was decreased from 9.3 to 7.1, zeta potential was decreased from -48.3 to -26.4 (mV), NaCl content increased from 0.49% to 7.32% and surface hydrophobicity increased from 177 to 372 (So/100 mg protein) after pickling for 8 weeks. After electrodialysis desalination treatment, the pH of SDEW was slightly increased and zeta potential was decreased; however, the NaCl content was reduced by 95% and surface hydrophobicity decreased by 30as, the SDS-PAGE pattern showed the same distribution of protein molecules. Electrodialysis desalination treatment did not affect emulsifying properties. The foamability and foam stability of SDEW decreased with increasing pickling time, but increased with electrodialysis desalination treatment. The gel strength of SDEW decreased with pickling time, but decreased sharply after electrodialysis desalination treatment.     

Production and characterisation of duck albumen hydrolysate using enzymatic process

Influences of different ultrasound treatments combined with heat pretreatment on enzymatic hydrolysis, emulsifying properties and antioxidant activities of hydrolysates from duck egg albumen were studied. Heat pretreatment at 95 °C for 30 min inhibited both serine and cysteine protease inhibitors effectively. Ultrasonication of heated duck albumen at 60% amplitude for 10 min yielded the highest surface hydrophobicity. Coincidentally, aforementioned pretreatment rendered the hydrolysate with highest degree of hydrolysis (DH) than other pretreatments when Alcalase was used. The resulting hydrolysate showed the highest antioxidant activities including DPPH radical and ABTS radical cation scavenging activities and ferric reducing antioxidant power as well as emulsifying properties when hydrolysis time of 90 min was used. The hydrolysate possessed the peptides with molecular weight of 219–255 Da with the highest ABTS radical scavenging activity. Thus, heat pretreatment, followed by ultrasonication of duck albumen under appropriate condition could increase DH, antioxidant activities and emulsifying properties of duck albumen hydrolysate.     

不同生产工艺对罗非鱼片的物理化学特性的影响研究

通过空气、真空和冷冻干燥等方法生产的罗非鱼,分析了样本的密度、多孔性以及毛孔大小分布,新鲜罗非鱼片的密度是1127kg／m^2,而分别通过空气、真空和冷冻干燥等方法生产罗非鱼肉的密度,依次是986,735and343kg／m^3冷冻干燥样本的多孔性比空气和真空干燥样本的高出很多。研究了罗非鱼片的过氧化值和颜色。     

Emulsifying and Foaming Properties of Protein Concentrates Prepared from Cowpea and Bambara Bean Using Different Drying Methods

Effect of cabinet-drying, vacuum-drying, and freeze-drying methods on the surface hydrophobicity, secondary structure, emulsifying, and foaming properties of protein concentrates prepared from different cultivars of cowpea and Bambara bean was investigated. The vacuum-drying method reduced hydrophobicity, while freeze-dried concentrates presented high hydrophobicity. The concentrates prepared by freeze drying presented more β-sheet (40–43%) and less β-turn (19–24%) structures. Bambara bean protein concentrates prepared by freeze-drying presented higher emulsifying activity (56–59%) compared to those by vacuum-drying and cabinet-drying, while emulsifying activity varied significantly among cultivars of cowpea (46–61%). Protein concentrates prepared by cabinet-drying showed the highest foaming ability.     

磷酸盐对巴氏杀菌全蛋液理化及功能性质的影响

为保护并改善巴氏杀菌全蛋液的功能特性,探究在巴氏杀菌条件下添加不同类型磷酸盐（磷酸氢二钠、焦磷酸钠和六偏磷酸钠）对全蛋液理化功能特性的影响,包括pH值、表面疏水性、色度、游离巯基、溶解度、起泡特性、乳化特性和凝胶特性。结果表明：相比巴氏杀菌后的全蛋液,3 种磷酸盐会降低全蛋液的表面疏水性和游离巯基含量,相对较高浓度的磷酸氢二钠（10、20 mmol/L）和焦磷酸钠（9、12 mmol/L）能够显著提高全蛋液pH值。另外,3 种磷酸盐都能显著改善全蛋液的溶解度、起泡特性和乳化能力,且达到巴氏杀菌前水平。其中添加12 mmol/L焦磷酸钠改善效果较为突出,全蛋液乳化能力和起泡能力分别提高了19.74%和30.49%,并显著改善了全蛋液凝胶的持水性,但会使乳化稳定性降低41.41%。色度结果表明,添加3 种磷酸盐都会提高全蛋液的黄度和红度。综合来看,3 种磷酸盐都表现出了很大的应用潜力,研究结果将为巴氏杀菌全蛋液功能性质的稳态化提供理论依据。     

Characteristics of Isolation and Functionality of Protein from Tomato Pomace Produced with Different Industrial Processing Methods

The seeds separated from tomato pomace may contain valuable protein with unique functional properties. The objectives of this research were to study the impact of industrial hot and cold break tomato processes on protein isolation from defatted tomato seed meal and determine the protein-related functional properties of defatted and non-defatted seed meals. The results showed that the high temperature of hot break process denatured the protein, resulting in the lower protein extraction yield from 9.07 % to 26.29 % for defatted hot break tomato seed (DHTS) compared to from 25.60 % to 32.56 % for defatted cold break tomato seed (DCTS) under various extraction conditions. Hot break process also significantly influenced protein-related functional properties of seed meals. Compared to DCTS, DHTS had higher water absorption capacity (WAC) and oil absorption capacity (OAC) based on the protein weight in the seed meal, but lower emulsifying ability (EA), emulsifying stability (ES), foaming capacity (FC), and foaming stability (FS) based on the whole seed sample weight. When compared to commercial soybean protein isolate (SP), the meals of hot break tomato seed (HTS), DHTS, and DCTS showed higher bulk density and WAC values. The FC and FS of tomato meals were inferior while the ES was superior to SP. High alkaline pH was beneficial to the protein extraction and achieved better EA, ES, FC and FS of all the samples. The results indicated that tomato seed meals have a great potential to be used as functional food ingredients.     

超声和渗透预处理对干燥草莓片品质及抗氧化活性影响

研究蔗糖、果糖、葡萄糖以及蔗糖结合超声渗透预处理对真空冷冻联合热风干燥草莓片品质及其抗氧化活性影响。结果表明:经预处理后干燥草莓片的品质、花色苷、总酚、黄酮、Vc含量和抗氧化能力均有显著性差异(p0.05),其中蔗糖结合超声前处理水分含量最低,硬度最高,而经蔗糖渗透处理的草莓片干燥后色泽与新鲜草莓最接近,a*最高;干燥后草莓片的花色苷、总酚和黄酮含量均高于鲜样,但Vc含量大大降低,其中经蔗糖结合超声预处理后的草莓片花色苷、总酚和黄酮含量最高,分别为22.68 g/L、7.52 mg/g、10.38 mg/g,其对-OH和DPPH清除率也高于其他组,但渗透和超声处理并不能提高草莓片Vc含量和铁离子还原能力;三种糖渍处理均能提高干燥草莓片品质,且蔗糖效果最佳。综上,渗透以及蔗糖结合超声预处理后草莓片品质以及抗氧化活性成分含量较高、抗氧化活性较强,适宜于草莓片的干燥。