天然抗菌活性物质在黑加仑果汁加工中的应用研究

研究了天然抗菌活性物质-新疆家蚕抗菌肽的耐热性及其对部分微生物的最小抑菌浓度,和其在不同pH条件下的溶解度及抑菌效果,并在此基础上进行正交实验,得到将其应用于黑加仑果汁加工中的最佳工艺条件。抗菌肽的添加可降低黑加仑果汁的杀菌强度,提高产品品质,为工业化生产应用提供科学依据。      

新疆家蚕抗菌肽在番茄汁加工中的应用研究

本文研究了新疆家蚕抗菌肽的耐热性及其对部分微生物的最小抑菌浓度,和其在不同pH值条件下的溶解度及抑菌效果。并在此基础上进行正交试验,得到将其应用于番茄汁加工中的最佳工艺条件,抗菌肽的添加可降低番茄汁的杀菌强度,提高产品品质,为工业化生产应用提供科学依据。     

黑加仑果汁加工中的关键工艺及其对果汁品质的影响

论述了黑加仑果汁加工的优化加工工艺流程和条件,重点阐述了酶解、热处理等关键工序的工艺控制研究情况,对这些工艺过程的控制原理、条件及其对黑加仑果汁品质的影响进行了总结,可用于指导黑加仑果汁的生产.     

巴氏杀菌对黑加仑果汁特性和DPPH自由基清除能力的影响

研究不同巴氏杀菌处理（70、80、90℃分别杀菌6、8、10 min）对黑加仑果汁物理化学特性（色度、浑浊度、p H）、生物活性成分（多酚、单宁、花色苷）含量及DPPH自由基清除能力的影响。采用Folin-Ciocalteu法、p H示差法、Folin-Denis法分别测定果汁中多酚、花色苷、单宁含量,用清除DPPH自由基活性方法分析抗氧化性,色差仪测定颜色变化。结果表明:杀菌温度70℃、杀菌时间6 min为适宜杀菌条件,杀菌温度升高和处理时间延长,果汁红色加深,对颜色变化影响明显（p<0.05）,果汁的浊度增大,果汁的p H随杀菌温度升高略有下降,但与杀菌前相比不显著（p>0.05）。黑加仑果汁中的多酚、单宁、花色苷含量和DPPH自由基清除率在杀菌温度70℃、杀菌时间6 min较高,随着杀菌温度的升高和杀菌时间的延长而降低,并且温度越高降低得越快。采用低温、短时的巴氏杀菌工艺更有利于保证果汁的性质和生物活性成分含量。      

黑加仑香槟酒研究的技术报告

分析了黑加仑浆果的营养组成,并对黑加仑果汁的提取、冷处理及果汁的保存进行了详细的报告,以及对黑加仑子香槟酒的配方、成品酒的澄清、除菌和生产工艺技术也作了说明,结果证明,产品的理化及卫生指标均符合标准要求。     

高压均质技术在果汁加工中的应用

果汁产品感官、营养品质提升及其安全性保障是其加工领域近年来亟待解决的关键难题和研究热点,而非热加工技术在杀菌的同时能最大限度地保留果汁原汁原味,其有望替代热加工技术.其中,高压均质技术从一种传统的均质化工艺逐渐发展成为非热加工技术而备受关注.基于前期的研究成果,该文从高压均质技术的发展历史和设备原理出发,对高压均质处理...     

澄清处理对黑加仑果汁物理化学特性的影响

本文研究了冷冻澄清、酶解澄清、热凝聚澄清和自然澄清处理对黑加仑原果汁物理化学特性的影响。采用色差仪测定颜色变化,采用Folin-Ciocalteu法、p H示差法、Folin-Denis法分别测定果汁中多酚、花色苷、单宁含量,用清除DPPH自由基活性方法评价抗氧化性。实验结果表明:澄清使果汁颜色变暗;使果汁浊度大幅减小,其中酶解澄清和热凝聚澄清的澄清效果比自然澄清和冷冻澄清更好;不同澄清处理对果汁p H没有显著影响（p>0.05）;不同澄清处理使果汁总酚含量、单宁含量、花色苷含量明显减少（p<0.05）;四种澄清处理后果汁的DPPH自由基清除率明显下降（p<0.05）。澄清处理影响黑加仑果汁物理化学特性。      

超高压技术在果汁生产中的应用

综述了近年超高压技术应用于果汁生产的研究结果,包括超高压对果汁中微生物,风味物质,酶,抗氧化性的影响,以及超高压果汁的包装和标签对生产工艺和消费者接受程度的影响。国内外的应用研究表明超高压技术是一项很有发展前景的果汁生产高新技术。     

黑加仑果汁中花色苷的贮藏稳定性

以黑加仑果汁为原料,研究不同温度、不同可溶性固形物含量和抗氧化剂（抗坏血酸）存在条件下贮藏过程中果汁花色苷的化学稳定性、降解动力学及颜色变化。结果表明：果汁中花色苷在4 ℃、可溶性固形物含量9°Brix条件下较稳定,随着贮藏温度升高和可溶性固形物含量升高,花色苷残留率越低。贮藏过程中花色苷的降解符合一级反应动力学,反应速率常数k越大,半衰期t1/2越小,活化能Ea越低。添加50 mg/L抗坏血酸使果汁花色苷降解速率常数k明显增大,半衰期t1/2和降解活化能Ea明显减小,因此抗坏血酸对花色苷残留率的减少有促进作用。在贮藏过程中随着时间的推移,花色苷不断的减少,果汁发生褐变,亮度和红色度逐渐降低,黄色度逐渐增加,而且抗坏血酸对贮藏过程中花色苷的颜色变化具有促进作用。     

Effect of juice processing on cranberry antibacterial properties

The effects of the industrial juice process on the ability of neutralized cranberry samples and extracts (polar, apolar and anthocyanins) to inhibit the growth of Enterococcus faecium resistant to vancomycin (ERV), Escherichia coli O157:H7 EDL 933, E. coli ATCC 25922, Listeria monocytogenes HPB 2812, Pseudomonas aeruginosa ATCC 15442, Salmonella Typhimurium SL1344 and Staphylococcus aureus ATCC 29213 were investigated. The juice process appeared to have a general enhancing effect on the antibacterial properties of cranberry polar and anthocyanin extracts. The lowest minimum inhibitory concentrations (MICs) (1.80–7.0 μg phenol/well) were obtained when S. aureus, S. Typhimurium, and ERV were exposed to the juice concentrate. The growth of P. aeruginosa, L. monocytogenes, E. coli ATCC, and E. coli O157:H7 was not inhibited by the juice concentrate, but did show sensitivity (maximal tolerated concentrations of 0.007–0.4 μg phenol/well). The lowest MICs (22.6–90.5 μg phenol/well) for P. aeruginosa, S. aureus, S. Typhimurium, and ERV were observed when they were exposed to the cranberry anthocyanin extract obtained from cranberry pomace. The results also showed a negative effect of the juice process on the antibacterial properties of the cranberry apolar extracts: the one obtained from frozen cranberries was most efficient against P. aeruginosa, S. aureus, L. monocytogenes and S. Typhimirium (MIC of 45.50 μg phenol/well). The tested bacteria showed the greatest resistance toward the cranberry extracts obtained from the mash and the macerated and depectinized mash.     

复合酶在苹果汁加工中的应用研究

将纤维素酶与α-淀粉酶结合果胶酶用于苹果汁加工过程中的液化与澄清,弥补现行果胶酶在酶系上的不足。通过正交实验获得了液化与澄清工艺的最佳组合参数,对于苹果汁的加工生产具有实际指导意义。     

酸菜发酵液中抑菌物质的提取与鉴定

通过低温浓缩法、浓度梯度盐析沉淀法、透析层析法从酸菜水中提纯一种肽类物质,经过抑菌试验检测发现其抑菌效果优于Nisin,利用UV-5800紫外分光光度计测定其吸光值,得到A280=0.195和A280=0.316两个峰值,通过尿素-SDS-聚丙烯酰胺凝胶电泳确定该物质的分子量主要包含3 510Da和22 000Da两部分,证实该物质虽属于小肽类抑菌物质但与Nisin不同。     

黑加仑调节血脂的功效研究

目的对新疆地产黑加仑的降脂功效进行评价,为黑加仑的进一步开发利用提供依据。方法按照《保健食品功能学评价程序》的相关内容进行。动物实验采用预防性高脂血模型法,在高脂血模型建立的同时予以黑加仑原汁进行干预,连续进行14d后,测定空腹12h血清中甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C),低密度脂蛋白胆固醇(LDL-C),观察体重变化。结果黑加仑干预组小鼠体重增长明显降低(P<0.05)。黑加仑中、高剂量组TG、TC、LDL-C明显低于高脂模型组,HDL-C明显高于高脂模型组(P<0.01)。结论黑加仑具有降低实验性高血脂小鼠血脂的功效。     

Effect of pectinolytic juice production on the extractability and fate of bilberry and black currant anthocyanins

Bilberries (Vaccinium myrtillus L.) and black currants (Ribes nigrum L.), dark blue berries rich in anthocyanins, were processed with an aid of commercial pectinolytic enzyme preparations, and the effect of processing on berry anthocyanins was investigated. The enzyme preparations were dosed based on their polygalacturonase activity from 1 to 100 nkat/g of berry mash. The juice yields were determined by weighing, and anthocyanin analyses were performed with HPLC. The bilberry and black currant juice yields increased significantly in enzyme-aided treatments with comparison to control, even with the lowest (1 nkat/g) polygalacturonase dosage. The anthocyanin yield increased by up to 83% for bilberries and up to 58% for black currants in enzyme-aided treatments as compared to control. The results showed that higher polygalacturonase dosage was needed for black currant to achieve the maximal juice and anthocyanin yields than for bilberries. The stability and the profile of extracted anthocyanins were greatly affected by the glycosidase side activities present in the enzyme preparations, which were able to hydrolyze certain anthocyanins to the corresponding aglycones. In addition, the data indicate that anthocyanidin rutinosides were more easily extracted than those of glucosides, which prevailed over the arabinosides and galactosides. Thus, prior to processing it is important to know the intact anthocyanin structures of the raw material, and the activity profile of the enzyme preparation to obtain optimal anthocyanin extractability and enzyme dosage.     

Effects of different enzymatic maceration treatments on enhancement of anthocyanins and other phenolics in black currant juice

Pre-press maceration treatments with 10 different pectinolytic enzyme preparations were investigated in experimental black currant juice production using response surface design templates. Enzyme dosage, maceration time, reaction temperature, and degree of berry crushing were varied, and the juice yields, anthocyanins, total phenols, and turbidity in the resulting juices were compared for a total of 250 different enzymatic treatments. The yields of anthocyanins and total phenols in the juices ranged from 900 to 2200 and 3050 to 5100 mg/kg wet weight black currant mash, respectively. Juice yields ranged from 66.4% to 78.9% by wet weight of mash. Turbidity levels ranged from 25 to 916 formazan nephelometric units (FNU). The reaction parameters induced larger variations in the responses than the different enzyme preparations, but the cloned Aspergillus niger/Aspergillus aculeatus preparation Pectinex BE® consistently tended to be among those giving the best responses regarding anthocyanin yields, phenols, and low juice turbidity. The optimal maceration was achieved using an enzyme dosage of 0.18% by wet weight of berries with a reaction at 60 °C for 30 min on the most finely crushed berry mash. This treatment gave similar profiles of anthocyanins in the juices with all the 10 enzyme preparations. The same 10 juices all exhibited antioxidant activity against human low-density lipoprotein oxidation in vitro, but the antioxidant potency varied depending on the enzyme preparation used in the pre-press maceration.     

黑胡椒抑菌活性物质提取工艺优化

为了研究黑胡椒中抑菌活性物质的提取工艺,以黑曲霉做指示菌,以提取率×抑菌圈直径为活性追踪指标,在单因素实验的基础上通过二次回归通用旋转组合设计进行工艺参数优化。结果表明,其最佳提取工艺条件为:乙醇浓度80%,浸泡时间480min,提取时间100min。      

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.     

芦荟汁饮料工艺研究

介绍了以芦荟为原料,配以苹果汁为辅料,运用先进的处理方法制备芦荟汁饮料,制订产品标准,并对确定工艺的几个主要问题进行了探讨。     

采用正渗透技术浓缩番茄汁

采用正渗透技术浓缩了番茄汁,研究了不同温度下,NaCl汲取液浓度对番茄汁浓缩速率的影响。实验结果表明:渗透速率随着温度升高而加快,当温度超过一定值时,渗透速率反而降低,随着NaCl溶液浓度的升高,渗透速率增加,浓缩时间大大缩短,最后浓缩番茄汁糖度可达到32°Brix。