Improved sauerkraut production with probiotic strain Lactobacillus plantarum L4 and Leuconostoc mesenteroides LMG 7954

Probiotic strain Lactobacillus plantarum L4 and strain Leuconostoc mesenteroides LMG 7954 were applied for the controlled fermentation of cabbage heads. The parameters of the controlled and spontaneous fermentations, including antimicrobial effect of cabbage brines obtained at the end of both fermentations, were monitored. To check out the influence of starter culture strains, 10 randomly chosen lactic acid bacteria, isolated at the end of controlled cabbage heads fermentation were identified by API 50 CHL test, and the presence of the probiotic culture was confirmed by Pulsed Field Gel Electrophoresis. The starter cultures applied for cabbage heads fermentation allowed lowering of NaCl concentrations from 4.0% to 2.5% (w/v), considerably accelerated fermentation process by 14 d, and improved the product quality. The produced sauerkraut heads are considered probiotic product as viable probiotic cells count in final product was higher than 10(6) colony-forming units (CFU) per gram of product. PRACTICAL APPLICATION: The results of this research could be applied in the production of fermented cabbage heads with added functional (probiotic) value and with lower NaCl concentration with expected shortened fermentation time. This could not only be of economic but also of ecological importance.     

乳酸酸菜保质期内乳酸含量的变化与分析

乳酸酸菜在保质期内乳酸含量的稳定性是乳酸酸菜的重要指标，本文测定了大庆思源牌乳酸酸菜乳酸含量的变化情况。测定结果表明，发酵法生产的乳酸酸菜，在真空保存的条件下，乳酸的含量是稳定的，为乳酸酸菜的质量标准建立了研究基础。     

无盐酸菜在发酵和贮藏过程中品质的变化

目的:探究无盐并接种乳酸菌发酵酸菜过程及低温贮藏过程中品质变化规律。方法:分析无盐酸菜发酵过程中的基本理化指标及贮存期间的品质变化。结果:无盐酸菜在发酵第5天达到成熟,发酵过程中,pH值、亚硝酸盐含量、还原糖含量和维生素C含量显著下降(P<0.05),其中维生素C含量减少了88.62%,总酸和总有机酸水平显著上升(P<0.05)。发酵成熟时,亚硝酸盐含量极低,达(0.23±0.10) mg/kg;其中有机酸主要为乳酸、草酸和醋酸,除琥珀酸外,其他有机酸如草酸、柠檬酸等发酵后均有增加,乳酸含量增加了26.5倍。4℃贮藏60 d,无盐酸菜的pH值、总酸含量无明显变化,亚硝酸盐含量持续降低。结论:发酵过程有效提高了无盐酸菜的酸味和鲜味,并保证了其优良的感官品质,且4℃下的贮藏性能良好,贮藏期为60 d。     

Capsular and slime-polysaccharide production by Lactobacillus rhamnosus JAAS8 isolated from Chinese sauerkraut: Potential application in fermented milk products

Exopolysaccharides (EPSs) produced by lactic acid bacteria (LAB) play an important role in the improvement of the physical properties of fermented dairy products. To find EPS-producing LAB strains with potential industrial applications, a Lactobacillus rhamnosus strain, L. rhamnosus JAAS8, that is capable of producing two forms of EPS when grown in MRS broth or semi-defined medium with glucose as a carbon source was isolated and identified from Chinese sauerkraut. The capsular-polysaccharide (CPS) present surrounding the bacterial surface of L. rhamnosus JAAS8 was observed by both optical microscopy and transmission electron microscopy. The slime-polysaccharide (SPS) present in the growth medium was produced mainly during the exponential growth phase, while the CPS was produced only in fermentation. Monosaccharide analysis of the purified polysaccharide samples showed that the CPS was composed of galactose and N-acetylglucosamine in a molar ratio of 5:1, and the SPS was composed of galactose, glucose and N-acetylglucosamine in a molar ratio of 4:1:1. The use of L. rhamnosus JAAS8 could be considered for potential applications in the dairy industry to improve the rheological properties of fermented milk products by increasing their water-holding capacity and viscosity.     

乳酸菌发酵对富源酸菜品质及安全性的影响

采用液态发酵方式,比较乳酸菌发酵和自然发酵的富源酸菜在整个贮藏过程中不同时段的感官、理化指标和微生物变化的规律,评价两种发酵方式对富源酸菜品质及安全性的影响。试验结果表明:与自然发酵相比,乳酸菌发酵的富源酸菜感官品质更优;亚硝酸盐含量较低且亚硝峰值出现得较早、pH值较低、总酸含量较高;乳酸菌活菌数量更多,菌落总数、霉菌和酵母菌数量都较少;大肠杆菌未检出。说明乳酸菌发酵制作的富源酸菜在品质及安全性方面都优于自然发酵的富源酸菜。     

提高酸菜风味包保存期品质的研究

探讨了盐度、酸度、杀菌条件及包装材质对酸菜风味包保存期品质的影响,结果表明盐度及酸度高有利于酸菜风味包的保存,调整酸菜风味包盐度为7%,酸度(总酸)为1.0%,采用铝箔膜进行抽真空包装,杀菌条件85℃,15 min,保存实验6周,酸菜风味包仍能保持较好的色泽及脆度,且风味变化较小。     

酸菜腌制及保藏方法的研究进展

酸菜的乳酸菌发酵作用、蛋白质分解作用以及风味形成过程赋予了产品特有的风味,因而受到越来越多人的喜爱。但是酸菜生产的季节性以及人们常年性需求之间的矛盾使得酸菜能够长期保藏显得尤为重要。但是酸菜在保藏过程中由于生物的、物理的以及化学作用使其容易腐败变质。为此,本文通过文献调研,分别从酸菜自身,外部工艺条件等角度出发,较全面地阐述了有效地延长酸菜保质期的方法,特别地强调了生物防腐剂以及拮抗微生物的应用前景。本文内容从食品安全以及市场化前景角度展望了未来酸菜腌制及保藏的发展方向,为相关领域的研究提供思路。     

Identification of Lactic Acid Bacterial Strains with High Conjugated Linoleic Acid-Producing Ability from Natural Sauerkraut Fermentations

ABSTRACT:  Natural sauerkraut fermentations contain a great number of lactic acid bacteria. The aim of this study was to identify lactic acid bacterial strains with high conjugated linoleic acid (CLA)-producing ability from natural sauerkraut fermentations. Fifteen CLA-producing lactic acid bacterial strains were isolated in the study. One of these strains, designated as NCUL005, showed the highest CLA-producing ability (0.623 mg/mL). The transformation efficiency of converting linoleic acid into CLA by NCUL005 was 26.67%. The CLA produced by NCUL005 comprised a mixture of 32.2% cis9, trans11-C18:2 isomer and 67.8% trans10, cis12-C18:2 isomer. NCUL005 was identified as Lactobacillus plantarum , based on its cell morphology, characteristics of lactic acid production, and analysis result from Biolog Microbial Identification System (BMIS).     

东北酸菜汁分离乳酸菌发酵鹿肉干加工工艺优化

为研制营养风味俱佳的发酵鹿肉干新产品,从东北自然发酵的酸菜汁中分离、纯化、鉴定乳酸菌菌株,分析该菌株与汉逊德巴利酵母菌的发酵特性,将二者以一定配比组成混合发酵剂用于块状鹿肉发酵并研究其发酵特性。单因素试验、Plackett-Burman优选试验和响应面优化块状鹿肉发酵工艺研究表明,发酵时间、发酵温度、接种量对鹿肉发酵特性影响显著;酸菜汁分离乳酸菌和汉逊德巴利酵母菌发酵鹿肉产酸快,利于风味物质形成,适宜作发酵鹿肉干发酵剂;得到发酵鹿肉的p H值、发酵鹿肉干感官评分与发酵时间、发酵温度、接种量间关系的二次回归方程;鹿肉最佳发酵工艺条件:发酵时间20.86 h、发酵温度27.51℃、接种量2.16 m L/100 g;发酵鹿肉的平均p H值为5.07时,发酵鹿肉干感官评分最高。     

多菌复合酸菜发酵剂工业化培养基的优化

利用廉价的原料来优化多菌复合酸菜发酵剂的发酵培养基,以满足工业化生产的需要。综合考虑菌体生物量和产品得率两因素,在混菌发酵的基础上,采用单因素实验和正交实验优选发酵培养基中各组分的最佳用量。确定培养基的最佳组合为:玉米糖化液2.5%、豆粕水解液1.5%、玉米浆0.5%、K2HPO42g/L、MgSO40.5g/L、MnSO420mg/L,优化后发酵培养的活菌数量可以达到2.06×109CFU/mL。菌种比例为副干酪乳杆菌(L1):布氏乳杆菌(L5):凝结芽孢杆菌(B.c)=1:2.12:2.87,该比例接近本实验室确定的酸菜复合发酵剂的菌种比例。