膜分离技术在菠萝汁加工中的应用研究

采用膜分离技术,包括超滤、反渗透、纳滤,分别对菠萝汁进行处理,研究了各种膜的运行时间与操作压力对膜分离效果的影响,并对膜分离效果进行评价.结果表明,超滤处理菠萝汁的最佳操作压力为0.12MPa,反渗透与纳滤处理菠萝汁的最佳操作压力均为0.50MPa.卷式膜的抗污染能力优于中空纤维式膜,碱液清洗后卷式膜的膜通量恢复率达到了96%以上;超滤膜分离可基本保留菠萝汁中的营养成分,并有效去除果汁中的微小颗粒物质.起到了澄清作用;反渗透与纳滤处理菠萝汁,能够对果汁起到一定的浓缩作用.     

膜技术在制备棉籽蛋白多肽中的应用研究

采用微滤膜对棉籽蛋白酶解液进行除杂,首先根据膜通量及蛋白透过率选定合适的微滤膜,再考察了操作压力和温度对选定微滤膜通量的影响。结果表明:膜孔径为100nm的微滤膜较30nm微滤膜更适合本物料体系。且随着分离时间的延长,膜通量逐渐减小,至20min~30min后,膜通量趋于稳定;膜通量与压力和温度在一定范围内呈正相关。     

有机微滤膜在分离谷氨酸菌体中的初步研究

利用有机微滤膜过滤谷氨酸发酵液,研究了有机膜去除菌体实验的操作条件温度和压力对膜通量的影响;实验表明：在最适操作条件下（50℃、0．14MPa）,膜对菌体的截留率大于98％,谷氨酸损失低于1％;膜清洗后通量恢复率超过98％,可满足生产的需要。     

PVDF微滤膜在天然儿茶染料制备中的应用

为提高植物染料儿茶的纯度及其染色效果,采用PVDF中空纤维微滤膜对儿茶染液进行精制,比较儿茶染液在膜分离前后的浑浊度及其所染毛织物、棉织物的颜色特征值,并测试在该分离体系中儿茶染液透过液流量与运行时间、色素浓度与运行时间的关系。结果表明：PVDF微滤膜分离技术降低了儿茶染液的浑浊度,提高了其对棉织物、毛织物上的染色性能;该分离体系运行1h后,儿茶染液膜通量降低、色素浓度下降,需对膜进行清洗;清洗剂选用强碱性NaOH为好,当膜污染情况比较严重时,采用超声波清洗可提高膜通量。     

聚偏氟乙烯微滤膜过滤纯生啤酒性能与滤菌效果研究

研究了指孔状结构和网状结构的亲水性聚偏氟乙烯(PVDF)微滤膜的滤菌性能与膜结构、膜孔径的关系,探讨了生啤酒过滤过程中膜结构、清洗方式对除菌效果和膜过滤通量的影响规律,通过SEM和接触角测定仪表征了微滤膜的结构和亲水性。结果表明:膜的结构对滤菌效果影响不大;0.22μm数量级的PVDF微滤膜的滤菌效果达到啤酒生产要求;清水清洗和碱、清水、酸、清水连续清洗两种清洗方式对网状结构的PVDF膜影响不大,其平衡过滤通量保持在22.2~22.4L/(m2·h),但碱、清水、酸、清水连续清洗方式更有利于指孔状结构PVDF膜性能的恢复,平衡通量约为40.8L/(m2·h),而同样条件下清水清洗的平衡通量为35.0L/(m2·h)。实验数据表明用亲水性的PVDF微滤膜过滤生啤除菌,仅采用清水清洗膜在操作上是可行的。     

陶瓷微滤膜纯化菊花黄酮的工艺研究

目的:研究无机陶瓷微滤膜分离纯化菊花总黄酮提取液,确定最佳的操作工艺条件。方法:以菊花总黄酮得率和膜通量稳定性为评价指标进行实验,对操作压力、溶液温度和膜的规格进行了优化。结果:最佳工艺条件为无机陶瓷膜孔径0.5μm、溶液温度50℃、操作压力0.30MPa,在此条件下,能使菊花黄酮达到较好地除杂和澄清的效果,菊花总黄酮转移率达90%以上,提取固形物中黄酮含量为19.81%,同时纯化过程稳定。结论:无机陶瓷微滤膜纯化菊花总黄酮提取液工艺简单可靠。     

超滤+纳滤回收甘薯淀粉加工废水中多糖的中试研究

为了探究超滤(UF)+纳滤(NF)组合工艺回收甘薯淀粉加工废水中多糖的技术可行性,通过UF+NF双膜法中试实验,研究了操作压力、进水流量、运行时间对NF膜分离效果的影响,采用正交实验优化了NF膜清洗参数。结果表明:当操作压力为0.2 MPa、进水流量为550 L/h时,UF(60 ku)对蛋白截留率为94.1%。NF最佳运行条件为操作压力0.3 MPa、进水流量450 L/h,运行时间3 h,透过液多糖浓度低于4.8 mg/L,多糖、化学需氧量(COD)截留率分别为98%、85.2%。清洗剂种类、清洗剂浓度、清洗时间对NF膜清洗效果影响显著(p0.01),而清洗温度对NF膜清洗效果影响不显著(p0.05),影响程度大小顺序为清洗时间清洗剂种类清洗剂浓度清洗温度;最优清洗参数时(温度30℃、清洗时间15 min、碱性蛋白酶浓度0.06%),NF膜通量恢复率为92.1%。     

PVDF管式膜纯化果葡糖浆的研究

果葡糖浆在食品工业中有着广泛的应用,而传统的分离方法无法除去糖液中的微生物等小颗粒,更不能除去蛋白质、胶体等物质。为此需要通过膜分离技术来实现糖液的澄清和纯化。本文采用PVDF管式膜材质分离纯化果葡糖浆,考察了不同运行时间下操作压力、料液浓度、料液温度和循环流量对果葡糖浆通量的影响,确定了最佳的操作条件,并对膜的在线清洗工艺进行了研究。当操作压力为0.20 MPa,循环流量为400 L/h,和料液温度70℃时,果葡糖浆的稳定通量达到5.47 L/(m2·s),果葡糖浆透过液的pH为3.9,色度、透光度、浊度和不溶性颗粒物含量分别为43%、99.2%、0.192%和4.5 mg/kg,完全达到生产要求;管式膜在关闭透过液出水阀门的条件下以料液清洗1 min时,果葡糖浆通量的恢复率可达90%以上。     

聚芳醚砜酮微滤膜在酱油除菌中的应用

选择聚芳醚砜酮(PPESK)中空纤维微滤膜对酱油原液进行除菌实验,代替其传统工艺中高温灭菌-静置沉降-多次过滤等工艺,考察了滤膜的除菌效果及操作参数(压力、温度、时间等)对渗透通量的影响,选择了冷、热水反洗和碱液清洗的方法对污染膜进行再生处理,并对反洗效果进行了考察比较,确定了最佳操作参数。结果表明,任何情况下滤膜的除菌率均达到100%,最佳操作压力为0.07MPa,可选择的操作温度范围较宽,在近30h内膜渗透通量变化较小,表现出较强的耐污染性,热水及碱液反洗均有很好的再生效果,渗透通量恢复率高至100%,而碱洗更佳。滤膜具有耐污染性、可长期操作性、耐高温性及耐碱腐蚀性等优良特性。     

结冷胶发酵液微滤除菌工艺

采用有机微滤膜对结冷胶发酵液进行过滤除菌实验。考察了不同膜材料的过滤性能,以及结冷胶浓度、温度、压力等操作参数对除菌效果的影响。将结冷胶发酵液脱酰基处理后稀释成浓度为3 g/L的料液,再将酸碱度调至pH10,在0.1 MPa、65℃下用孔径为0.45μm的聚醚砜膜过滤,菌体去除率和结冷胶回收率分别为97%和84%。滤膜污染后采用0.75%HCl和1%NaOH交替清洗,可使膜通量得到较好地恢复。     

Effect of membrane property and operating conditions on phytochemical properties and permeate flux during clarification of pineapple juice

The effects of membrane property on the permeate flux, membrane fouling and quality of clarified pineapple juice were studied. Both microfiltration (membrane pore size of 0.1 and 0.2 μm) and ultrafiltration (membrane molecular weight cut-off (MWCO) of 30 and 100 kDa) membranes were employed. Membrane filtration did not have significant effects on the pH, reducing sugar and acidity of clarified juice whereas the suspended solids and microorganism were completely removed. The 0.2 μm membrane gave the highest permeate flux, total vitamin C content, total phenolic content and antioxidant capacity as well as the highest value of irreversible fouling. Based on these results, the membrane with pore size of 0.2 μm was considered to be the most suitable membrane for the clarification of pineapple juice. The optimum operating conditions for the clarification pineapple juice by membrane filtration was a cross-flow velocity of 3.4 ms⁻¹ and transmembrane pressure (TMP) of 0.7 bar. An average flux of about 37 lm⁻² h⁻¹ was obtained during the microfiltration of pineapple juice under the optimum conditions using batch concentration mode.     

超滤法澄清西番莲果汁的研究

以寻求提高西番莲原汁超滤时的渗透通量为目的，用国产芳香聚酰胺膜平板超滤器进行试验，对超滤操作条件，果汁预处理，膜的清洗进行研究。结果表明，西番莲原汁超滤时渗透通量最高的操作压力为0．15MPa，最佳进料速度为22mL/s，操作温度为室温；原汁经海藻酸钠—碳酸钠澄清剂预处理后可以明显增大渗透通量；超滤处理后。原汁的西番莲固有滋味和品质得到较好保留。采用超滤澄清法生产高质量的西番莲原汁是可行的。     

Evaluation of hybrid pressure-driven and osmotically-driven membrane process for non-thermal production of apple juice concentrate

This study investigates the potential of hybrid membrane processes including microfiltration (MF), ultrafiltration (UF) and forward osmosis (FO) for non-thermal concentration of apple juice. The process performance and characteristics (physicochemical properties, nutritional and aroma components and microbiological quality) of apple juice were studied. The clarity of apple juice was significantly promoted as pore size of membrane reduced. MF and UF can also ensure microbiological safety in pre-treated apple juice. According to its efficiency of filtration as well as performance of simultaneous clarification and cold-sterilization, 0.22 μm MF membrane was identified as the optimal membrane for the pre-treatment. The pre-treated apple juice can be concentrated up to 65°Brix by subsequent single stage FO. FO retained nutritional and volatile compounds of apple juice while significant reductions were found in the juice concentrated by vacuum evaporation. Hybrid MF-FO can be a promising non-thermal technology to produce apple juice concentrate with high quality.     

几种澄清方法对梨汁理化和感官等指标的影响

本文研究了无机陶瓷微滤膜微滤、中空纤维超滤以及果胶酶对梨汁的澄清效果、理化及感官指标的影响。采用三种孔径的氧化铝膜和自制的加压微滤装置、外购中空纤维超滤装置以及果胶酶进行澄清实验。实验结果表明:(1)0.2μm孔径无机陶瓷膜微滤对梨汁的可溶性固形物含量、VC含量和还原糖含量影响不大,澄清梨汁得率较高,并且基本保持了梨汁的原有风味,适合梨汁澄清生产。(2)50nm无机陶瓷膜微滤和中空纤维超滤因孔径太小,不适合梨汁澄清生产。(3)0.8μm孔径无机陶瓷膜微滤和果胶酶澄清处理梨汁的浊度太大,短时间出现分层或沉淀,不适合梨汁澄清生产。     

EFFECT of pH and ENZYMATIC TREATMENT ON MICROFILTRATION and ULTRAFILTRATION of TANGERINE JUICE

Tangerine (Citrus reticulata blanco) juice clarification by crossflow microfiltration and ultrafiltration using polysulphone flat sheet membranes with nominal molecular weight cut off of 25,000, 50,000, 100,000 and 0.1 μm, 0.2 μm pore sizes was studied. the juice was pretreated by polygalacturonase and pH adjustment. the treated juice was clarified with a laboratory scale filtration unit with effective filtration area of 14 cm². Filtration conditions were transmembrane pressure of 93 to 194 kPa, crossflow velocity of 0.96 to 3.5 m/s and 25°C. Membrane performance was evaluated in terms of volume flux and clarity (% transmittance) of the permeate. Pretreatment of the juice by polygalacturonase and adjustment to pH 2 with HCl resulted in a clearer supernatant than enzyme treatment alone. Maximum flux was obtained with the 0.1 μm microfiltration membrane. Flux increased with transmembrane pressure and crossflow velocity. Flux at 194 kPa and 3.5 m/s was 69 L per square meter per hour. Permeate clarity was better at higher transmembrane pressure and lower velocity, due to the effect of the polarized/fouling layer of solute on the membrane surface, which acted as a secondary “dynamic” filter.     

微滤-超滤联用技术优化牛初乳乳清中IgG富集工艺

为了高效富集IgG的同时减轻牛初乳的浪费问题,提高产品价值,本文采用微滤-超滤联用技术对牛初乳乳清中IgG进行富集。首先探究了微滤技术在牛初乳乳清除菌中的应用,并对其操作工艺进行优化,其次,利用超滤技术对微滤除菌后的牛初乳乳清进行富集,在单因素实验基础上,采用响应面对超滤工艺进行优化,并对富集后的牛初乳乳清进行品质分析。结果表明:牛初乳乳清微滤除菌的最佳工艺参数为:微滤压力为0.2 MPa、温度为30 ℃,超滤富集的最佳工艺参数为:超滤压力为0.15 MPa、温度为35 ℃、浓缩倍数为6倍、稀释次数为4次,按此条件进行牛初乳乳清的微滤-超滤操作,此时的IgG浓缩率为58.19%,膜通量为204.46 L/m2·h。富集后的牛初乳乳清品质分析表明:IgG含量为22760 μg/mL,IgG活性为718.31 IU/L,蛋白质含量为7.86%,脂肪含量为0.035%,菌落总数为2.4 lg CFU/mL。本研究为牛初乳乳清中IgG的进一步开发与综合利用提供了一定的参考依据。     

超声作用对葡萄汁膜过滤工艺的影响

将超声波技术应用于葡萄汁的超滤膜过滤过程,研究了超滤膜孔径、跨膜压力、超声功率、超声频率等因素对超滤膜通量的影响,结果表明:采用200目滤布的板框过滤使后续的超滤过滤有较大的膜通量.超声波作用下,适宜的葡萄汁超滤膜工艺参数为:跨膜压力0.25 MPa、膜滤温度50℃、超声功率200W和频率40kHz.同无超声波作用相比...     

Combinatorial optimality of membrane morphology and feedstock during microfiltration of bottle gourd juice

The combinatorial optimality of membrane morphology and process parameters during dead end microfiltration of bottle gourd juice have been addressed in this article. Saw dust and kaolin based low cost ceramic membranes with varied morphology have been chosen to evaluate upon their microfiltration performance. For the chosen membranes, fresh, paper filtered and centrifuged juice samples were considered along with transmembrane pressure differential as process parameters. Combinatorial optimality was based on flux decline trends, fitness of fouling models, irreversible and reversible fouling data, irreversible permeation resistance and nutritional analysis of the permeate samples. An interesting feature of the article had been with respect to feed constitution playing a critical role in influencing the optimal choice of membrane morphology and transmembrane pressure differentials. Among all cases, paper filtered bottle gourd juice, 0.75 μm membrane and 137.9 kPa transmembrane pressure were found to be the best choice in terms of minimal irreversible fouling, lowest protein content, good clarity, good polyphenol and antioxidant activity in the permeate and appropriate flux.     

丁二酸发酵液的膜分离过程研究

通过微滤、超滤等膜分离技术对丁二酸发酵液进行了分离纯化,考察了温度、压力差、pH值、循环流速等因素及操作方式对丁二酸分离的影响。丁二酸发酵液经稀释后可直接进行微滤操作,微滤的优化工艺条件为:pH5.0,40℃,△P=0.03MPa,循环流速0.71m/s,采用间歇反冲可降低膜污染程度,维持较高通量;微滤除菌率达99.6%,蛋白质去除率87%,脱色率92%。将得到的微滤液在20℃,pH5.0,△P=0.05MPa,0.83 m/s循环流速下进行超滤,滤液透光率≥60%,蛋白质质量浓度仅5mg/L。经2步膜分离,蛋白质去除率达99.45%,丁二酸收率达93%。     

膜分离技术及其在果汁加工中的应用

介绍了应用于果汁加工中的膜分离过程(微滤、超滤、纳滤、反渗透、电渗析、膜蒸馏)及其分离性能。由渗透通量和截留率表征,在果汁加工中,膜分离技术可用于果汁的澄清、浓缩、脱气、脱苦、脱酸、脱色等。