共查询到19条相似文献，搜索用时 78 毫秒
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为提高黑毛豆仁膨化产品的品质,采用微波联合气流膨化干燥工艺。考察不同单位质量微波功率对黑毛豆仁干燥特性的影响,探讨联合干燥过程转换点含水率、膨化温度、停滞时间、压力差、抽空干燥时间对黑毛豆仁膨化产品的含水率、硬度、脆度和色泽的影响。结果表明:当单位质量微波功率为5W/g时,黑毛豆仁的干燥速率较快,干燥时间较短;联合干燥转换点含水率、膨化温度、抽空干燥时间对膨化产品的品质影响显著,而膨化压力差、停滞时间对膨化产品品质影响较小。确定黑毛豆仁微波联合气流膨化干燥适宜的工艺参数:单位质量微波功率5W/g,转换点含水率31%,压力差0.124MPa,膨化温度100℃,停滞时间10min,抽空干燥时间90min。研究结果可为黑毛豆仁干制品的产业化生产提供技术参考。 相似文献
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为了揭示空气介质对苹果片红外漂烫的传热作用机制以及对膨化干制的影响，该研究将介质湿度控制技术用于苹果片红外漂烫预处理中，利用数值模拟方法并结合苹果漂烫干燥试验，解析不同介质湿度下苹果片红外漂烫的传热传质规律，探究基于介质湿度控制的红外漂烫预处理对干燥效率和膨化干燥后产品色泽的影响。研究结果表明，基于红外辐射与对流传热原理的数学模型，并考虑物料水分蒸发与蒸汽冷凝能够较好描述红外漂烫的传热传质过程。物料含水率与温度模拟结果的相对误差为0.54%和0.39%。在恒定120℃红外加热温度下，介质相对湿度对苹果片红外漂烫的热质传递、漂烫后干燥效率与产品色泽均具有明显的影响。在低湿的状态下（1%相对湿度）进行红外漂烫，物料表面水分快速向空气介质中蒸发扩散，伴随的水分蒸发耗热量占物料吸热总量的40%，致使物料升温缓慢。将介质湿度提高至50%相对湿度能够抑制苹果片表面的水分蒸发，同时介质中水蒸气冷凝放热能够大幅提高漂烫初期的物料升温速度，漂烫120 s后物料中心温度迅速提高至86.8℃。因此，提高红外漂烫的介质湿度能显著提高漂烫后苹果片干燥速率与产品色泽。与1%相对湿度相比，在120℃、50%相对湿度下红外漂烫后苹果片的预干燥时间缩短了8.3%，苹果片干燥的色差值与褐变指数分别降低了55.6%和37.4%，护色效果优于热水漂烫。研究结果为苹果片等果蔬高质高效干燥的红外漂烫预处理工艺开发提供了新思路。 相似文献
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不同预处理对铁皮石斛热风干燥特性及品质的影响 总被引：1，自引：1，他引：0
为了优化铁皮石斛干燥工艺,降低其品质劣变风险,对热风干燥前的铁皮石斛鲜条进行直接剪切、烫漂和冻融预处理。研究不同预处理条件的铁皮石斛干燥特性和品质变化;利用低场核磁共振技术分析预处理对铁皮石斛干燥过程中水分迁移的影响。结果表明,预处理是影响铁皮石斛热风干燥过程的重要因素。与直接剪切相比,烫漂和冻融预处理提高了水分有效扩散系数,缩短了干燥时间,降低了能耗,尤以冻融预处理最为显著,干燥时间缩短了44.4%,能耗降低了42.76%（P<0.05）。微观结构观察表明,烫漂和冻融预处理使铁皮石斛组织间隙变大,细胞壁受到破坏,减弱了铁皮石斛组织对水分的束缚并增强了水分流动性,引起水分的重新分布,有利于水分迁移。低场核磁共振技术分析显示,干燥过程中去除的主要是自由水,烫漂和冻融预处理均降低了自由水的脱除时间,冻融预处理去除自由水的时间最少,为120 min。与直接剪切相比,冻融预处理提高了铁皮石斛干品中多糖和多酚的含量,分别提高了10.66%和12.32%,而烫漂预处理降低了铁皮石斛多糖和多酚的含量,分别降低了11.73%和14.73%,3种预处理铁皮石斛生物碱含量差异不显著（P>0.05）。总之,冻融预处理方法可以降低铁皮石斛干燥品质劣变风险,研究结果为石斛加工规范化生产提供参考。 相似文献
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使用固相微萃取(HS/SPME)-气质联用(GC/MS)技术对苏99-8毛豆仁鲜样和热风干燥毛豆仁挥发性成分进行分析,同时对2种干燥产品的感官品质、营养成分含量和质构特性进行比较。结果表明,在毛豆仁鲜样、热风干燥和热风联合压差膨化干燥制备的毛豆仁产品中分别检测出32、31、35种风味成分。鲜样中(Z)-3-己烯醇、正己醛、(E)-2-己烯醛、1-辛烯-3酮和1-戊烯-3酮对其风味相对贡献较大。热风联合压差膨化干燥后毛豆仁醛类化合物明显增多,出现了杂环类、酯类、酸类及含硫化合物,2-庚烯醛、正己醛、正戊醛、1-辛烯-3-醇、2-辛烯醇、1-辛烯-3酮、乙酸异丙烯酯、2,3,5-三甲基吡嗪和2,6-二甲基吡嗪、二甲基亚砜对热风联合压差膨化干燥后毛豆仁风味贡献较大,使毛豆具有较浓的豆类清香味和浓厚的焙烤香气,造就了热风联合压差膨化干燥毛豆仁脆粒的独特风味。热风联合压差膨化干燥毛豆仁的感官品质和质构特性明显优于热风干燥毛豆仁。 相似文献
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乙醇对红枣片CO2低温压差膨化干燥品质的影响 总被引：1，自引：1，他引：0
为了提高红枣的干燥品质,探究乙醇喷雾浸润预处理对膨化干燥效果的影响,该研究利用渗入红枣的高压CO2及乙醇作为动力源对红枣片进行低温高压渗透膨化干燥。以单因素试验为基础,对比研究预处理方式为无处理、热风干燥、乙醇喷雾浸润的 CO2低温压差膨化干燥、水分闪蒸干燥的膨化干燥品质及理化特性。优化枣片在乙醇喷润预处理方式下CO2低温压差膨化干燥工艺,研究乙醇喷雾浸润后含湿率、膨化压差、膨化温度、抽真空时长等因素对枣的膨化度、脆度、硬度、复水比的影响。结果表明,优化工艺为：乙醇浸润后含湿率19.3%、膨化压差1.08 MPa、膨化温度81.26 ℃、抽真空干燥时长151.13 min,膨化度为3.48,硬度为1 717.06 g,脆度为3 675.89 g,复水比为2.21。扫描电镜显示,乙醇具有溶解细胞壁成分的能力,可以改变结构来增加其渗透性,使CO2充分进入枣片中增大膨化动力,形成更有规律更大的孔隙。水和乙醇混合物的汽化热低于水的汽化热,与预处理方式为无处理、热风干燥的CO2低温压差膨化干燥及水分闪蒸干燥方法比较,乙醇浸润预处理可以表现出更好的膨化度、色泽、维生素 C 含量和显著缩短的干燥时间（P<0.05）。因此,乙醇喷雾浸润预处理后进行CO2低温压差膨化干燥是一种高效的干燥技术,所得的枣脆片品质较好。研究结果为红枣片的干燥品质及工艺优化分析提供了一定的理论基础。 相似文献
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影响柑橘变温压差膨化干燥的因素研究 总被引：7，自引：2，他引：7
采用变温压差膨化干燥技术,探讨预干燥后水分含量、膨化温度、抽空温度、抽空时间、停滞时间和压力差等因素对柑橘膨化产品的水分含量、脆度、膨化度和色泽的影响。研究结果表明:原料预干燥后含水量、膨化温度和抽空时间对膨化柑橘含水量、脆度、膨化度和色泽有显著影响;预干燥后,含水量在35.37%左右,膨化温度为90℃,抽空温度为80℃,抽空时间为2h较为合适;停滞时间、压力差在一定范围内对柑橘膨化产品质量的影响不太,试验确定停滞时间和压力差分别为5min和0.1MPa。 相似文献
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响应面法优化青麦仁的真空充氮烫漂护色工艺 总被引：1，自引：0，他引：1
为防止青麦仁在加工储藏过程中的酶促褐变,采用真空充氮烫漂技术对青麦仁进行处理,以多酚氧化酶活性和色泽差为考察指标,进行综合评分,利用单因素试验考察烫漂温度、烫漂时间、真空度对护色效果的影响,并通过响应面优化法建立护色效果综合评分和真空充氮烫漂处理条件之间的响应模型。结果表明,3个因素对青麦仁的护色效果均有显著影响,最优的工艺参数为:烫漂温度99.6℃、烫漂时间5.7 min、真空度0.08 MPa,此条件处理后的青麦仁PPO活性为80.04 U,ΔE值为0.57,所得到的真空充氮烫漂工艺回归模型显著(R~2=0.9851),拟合性好,可用于预测青麦仁的护色效果。本研究得到的真空充氮烫漂工艺参数为青麦仁原料的预处理和后续产品的开发提供了一定的理论依据。 相似文献
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班豆在浸泡加工过程中吸水特性的模拟 总被引：1，自引：0，他引：1
在生产速食干豆过程中,主要包括浸泡、蒸煮和干燥等工序。浸泡的温度和时间直接影响到在浸泡过程中固性物的损失和最终产品的质量。该研究测定了班豆在浸泡过程中在不同温度和时间下的吸水和固性物的损失特性,同时利用数学模型预测了在变温情况下班豆的吸水特性。该研究结果将对生产高质量的速食班豆有一定的指导作用 相似文献
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为研究超高压、热烫、冻藏3种不同的前处理方式对虾蛄脱壳效率及肌肉品质的影响,通过对脱壳时间、虾蛄仁得率、汁液流失率、虾蛄仁质构、色泽和肌原纤维蛋白含量等进行分析,以确定合适的虾蛄脱壳前处理方式。结果表明,与热烫、冻藏处理相比,超高压前处理能较好的缩减虾蛄脱壳时间,降低汁液流失率,提高虾蛄仁得率及其完整性,同时超高压处理能较好的提升虾蛄仁的硬度、弹性、咀嚼性和黏聚性。当压强为350 MPa、保压时间为8 min时,超高压处理对虾蛄脱壳效率及肌肉质构的提升效果最好;超高压处理后虾蛄仁pH值和水分含量略有增加,而其肌原纤维蛋白含量有不同程度的下降。综合考虑,350 MPa保压8 min的超高压前处理,能在提高虾蛄脱壳效率的同时较好的保持其肌肉品质。本研究结果为辅助虾蛄高效脱壳及超高压技术在水产品加工中的应用提供了依据。 相似文献
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干燥效率低导致的能耗高、品质劣变是果蔬热风干燥加工面临的严峻挑战。为改善胡萝卜热风干燥特性,该研究以横切和纵切方式获得的胡萝卜片为研究材料,对其进行穿刺（perforation pretreatment,PT）、乙醇浸渍（alcohol pretreatment,AT）和穿刺协同乙醇浸渍预处理（perforation synergistic alcohol pretreatment,PAT）。研究发现：同未预处理的胡萝卜片相比,PT、AT和PAT预处理技术的应用均显著提高了胡萝卜有效水分扩散系数及热风干燥速率,并将干燥时间缩短10.61%～50.00%,其中PAT样品干燥时间最短。相同预处理方式下,纵切的胡萝卜片相比于横切表现出较高的有效水分扩散系数、较快的干燥速率及较短的干燥时间。进一步,我们提出了PAT预处理具有较高干燥效率的“三重奏机制”：预脱水降低干燥负荷、毛细管流促进水分传质、细胞通透性的增强降低水分传质阻力。在品质方面,PAT预处理显著改善了纵切胡萝卜片的体积收缩、复水性、色泽、总类胡萝卜素和抗坏血酸含量、抗氧化活性及风味等品质特性。因此,为高效获得品质相对较优的脱水胡萝卜,可在其纵向切片后进行PAT预处理。该研究为改善胡萝卜热风干燥提供了一种简单有效的预处理技术,同时也为其他果蔬提质、增效、节能干燥提供参考。 相似文献
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McDougall GJ Gordon S Brennan R Stewart D 《Journal of agricultural and food chemistry》2005,53(20):7878-7885
Putative flavanol-anthocyanin condensation products were detected in a polyphenol-rich concentrate from black currant (Ribes nigrum L.). These compounds had UV-vis spectra similar to those of delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside, but eluted before all previously described anthocyanins on reversed phase HPLC. Mass spectrometric data indicated that they were rutinoside derivatives of novel aglycons 304 amu greater than delphinidin and cyanidin, respectively. The compounds were partly purified by semipreparative HPLC and gave MS and MS2 spectra consistent with anthocyanin rutinosides covalently linked to epigallocatechin or gallocatechin. These compounds are similar in structure to compounds thought to influence color and quality in red wines and strawberry juice products. There was also evidence for the presence of a range of other flavanol-anthocyanin condensation products. The compounds were present at differing levels in juices of 10 black currant varieties, which were roughly correlated to the content of the parent anthocyanins. The flavanol-anthocyanin products were present in polyphenol-enriched concentrates obtained by solid phase extraction, in commercially produced concentrates, and in fresh extracts of black currants. This suggests that the compounds were not artifacts formed during concentration or purification. However, differences in their comparative contents may be related to the lability of the parent anthocyanins during processing. Although present at low levels, the flavanol-anthocyanin products may influence color or quality parameters of black currant juices, and they may confer enhanced stability to the biological activities reported for their anthocyanin parents. 相似文献
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Starch is often added to batters to improve the texture and appearance of fried food products. However, comparisons of commercially available starches in terms of batter characteristics are rare. In this study, various corn starches, native or modified, were mixed with wheat flour (20% dry solids basis), and the physical properties of the batters after deep-fat frying were examined. Native corn starches of different amylose contents (high-amylose, normal, and waxy) and chemically modified corn starches (oxidized and cross-linked) were tested. The batter was prepared by adding water to the starch-flour mixtures (42% solids) and deep-fat frying at 180°C for 30 sec. The texture of the fried batter was analyzed using a texture analyzer (TA) with a Kramer shear cell. The pasting viscosity profile of the starch-flour mixtures (7% solids in water) was also measured with a Rapid Visco Analyser. When the native corn starches of different amylose contents were compared, the crispness (peak number before breakage) and hardness (maximum peak force) measured using the instrument were positively correlated with the amylose content in starches but negatively correlated with the residual moisture content of the fried batters. The peak viscosity and breakdown in viscosity profiles of the starch-flour mixtures were also negatively correlated with crispness. The use of high-amylose corn starch was effective not only in increasing the crispness, but also in reducing the oil uptake. However, the fried batter containing high-amylose starch was denser and harder than the batter containing normal starch. Among the modified starches tested, oxidized (0.4% active Cl2) and cross-linked (4% 99:1 mixture of STMP and STPP) starches showed improvements in the overall properties of the fried batters. With excessive oxidizations (>0.4% Cl2), however, the crispness was reduced. 相似文献
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为了实现对蓝靛果忍冬果实品质无损检测,以蓝靛果忍冬果实作为研究对象,采集果实表皮颜色图像信息并提取颜色特征参数,测定不同采收时间蓝靛果忍冬果实花青素含量,探究颜色变化与花青素含量变化相关性,建立颜色与花青素含量之间的回归预测模型。依据蓝靛果忍冬果实颜色特征参数,采用高斯算法建立花青素含量预测模型。结果表明,自蓝靛果忍冬果实生长的第四阶段半转色期Ⅱ开始,花青素含量快速升高,在第七阶段成熟期达到最高,在此过程中果实颜色由红色明显转为紫黑色;在蓝靛果忍冬果实生长和成熟过程中,以果实三原色和颜色饱和度的单一分量及其算术运算得到组合分量构成了21个颜色特征参数,这些参数与花青素含量有显著相关性(P<0.01);基于果实原色中绿色和蓝色值归一化处理的差值建立花青素含量最优高斯模型,有准确度高(Rc2=0.993)、误差低(CRMSE=4.752 mg/100g)、需用参数少(1个)的特点,适用于预测蓝靛果忍冬果实的花青素含量。研究结果可为蓝靛果忍冬生长期间的花青素含量无损检测提供模型依据。 相似文献
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三种干燥技术对红枣脆片干燥特性和品质的影响 总被引：9，自引：6，他引：3
为了解决传统油炸红枣脆片含油率高、维生素C损失严重及褐变等问题,探索红枣脆片新的加工方法,该文以新鲜脆熟期红枣为原料,利用气体射流冲击、中短波红外、真空脉动3种干燥技术进行非油炸红枣脆片的生产加工,对比了3种干燥方式对红枣脆片的干燥特性、色泽、维生素C保留率、复水性能、质地以及微观结构的影响。结果表明：1）红枣脆片在3种干燥方式下均表现为降速干燥,其中气体射流冲击干燥时间最短,为105 min,气体射流冲击、中短波红外、真空脉动干燥方式的水分有效扩散系数分别为1.55×10-9、1.03×10-9、0.89×10-9 m2/s;2）干燥方式对枣片色泽具有显著性影响（P<0.05）,真空脉动干燥所得枣片与新鲜枣片色泽最为接近;3）气体射流冲击、中短波红外、真空脉动干燥方式干燥后红枣脆片的维生素C保留率分别为51.5%、49.0%、66.6%,真空脉动干燥所得枣片维生素C含量保存率明显高于其他两种干燥方式（P<0.05）;4）气体射流冲击、中短波红外、真空脉动干燥方式加工的红枣脆片脆度分别为8.64、8.77、11.38 N,真空脉动干燥方式所得枣片最为酥脆;5）扫描电镜观测表明3种干燥方式均能得到疏松多孔的组织结构,真空脉动干燥所得枣片比气体射流和中短波红外干燥所得枣片组织结构更为疏松。从干燥时间来看气体射流冲击干燥耗时最短,但3种干燥方式所得红枣脆片色泽、维生素C保留率、复水性能和质地均以真空脉动干燥最优。该研究为低含油率和高品质红枣脆片的加工工艺选择提供了一定的理论依据。 相似文献
18.
Brenes CH Del Pozo-Insfran D Talcott ST 《Journal of agricultural and food chemistry》2005,53(1):49-56
The stability of red grape anthocyanins (Vitis vinifera) was evaluated in a model juice system during normal (25 degrees C) and accelerated storage (35 degrees C) in the presence of ascorbic acid. Rosemary polyphenolic cofactors (0, 0.2, and 0.4% v/v) were evaluated as anthocyanin stabilizing agents. Cofactor addition resulted in concentration-dependent hyperchromic (up to 178%) and bathochromic (up to 23 nm) shifts, indicating a more intense red coloration of the models. Anthocyanin and ascorbic acid degradation followed first-order kinetics during storage. Results showed that copigmented treatments underwent a lower conversion of L-ascorbic acid into dehydroascorbic acid during storage when compared to the control, favorably impacting the vitamin retention of these models. Copigmentation did not affect anthocyanin degradation in the absence of ascorbic acid but in its presence aided to retain a higher anthocyanin content than the control. This study indicated that the addition of anthocyanin cofactors could be used to reduce the pigment and vitamin degradation while masking detrimental color changes in anthocyanin containing products. 相似文献
19.
K A Taiwo A Angersbach B I Ade-Omowaye D Knorr 《Journal of agricultural and food chemistry》2001,49(6):2804-2811
This study compared mass transfer during osmotic dehydration (OD) and some quality indices of untreated apple slices to those of apple slices pretreated by either blanching, freezing, or applying high-intensity electric field pulses (HELP) or high pressure (HP). HP, HELP, and blanching increased water loss. Untreated and HELP-treated samples had comparable solids gains, which were lower (P < 0.05) than in the other samples. Apple slices turned brown after pretreatment but the L values of these samples increased with OD. The breaking force of dried samples increased with OD time, and pretreated samples had firmer dried texture than the untreated. Vitamin C content decreased with OD time, but HP- and HELP-treated apples had better retention of vitamin C. 相似文献