Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Effect of Lactic Acid Bacteria and Yeast Starter Cultures on the Soaking Time and Quality of “Ofada” Rice

Freshly harvested paddy rice was randomly obtained from three different farms in “Ofada” town, Ogun State, Nigeria and processed according to the traditional parboiling method. The rice was inoculated singly with cultures of Lactobacillus amylophilus, Leuconostoc mesenteroides, Saccharomyces uvarum and Saccharomyces cerevisiae which were isolated from the soak-water. In order to assess the effect of starter cultures on the soaking time of the rice, the pH and titratable acidity were determined at 12 h interval. The chemical composition and the sensory quality of the rice were also determined at the end of the soaking period while uninoculated rice served as control. The chemical composition of the rice as well as the pH and TTA of the soak-water were significantly (p < 0.05) different from the control while the processing time was shortened to 48 h. The rice inoculated with Saccharomyces uvarum and Saccharomyces cerevisae had the highest protein content and best sensory attributes.

Fermented Dairy Products: Starter Cultures and Potential Nutritional Benefits

Fermented dairy products have long been an important component of nutritional diet. Historically, fermentation proc-ess involved unpredictable and slow souring of milk caused by the organisms inherently present in milk. However, modern microbiological processes have resulted in the production of different fermented milk products of higher nutri-tional value under controlled conditions. These products represent an important component of functional foods, and intense research efforts are under way to develop dairy products into which probiotic organisms are incorporated to make them more valuable. This article provides an overview of the different starter cultures and health benefits of fer-mented dairy products, which can be derived by the consumers through their regular intake.

Effect of a compound starter cultures inoculation on bacterial profile and biogenic amine accumulation in Chinese Sichuan sausages

Effects of a starter culture composed of Lactobacillus sakei,Pediococcus pentosaceus,Staphylococcus xylosus and S.carnosus at the ratios(m/m)of 1:1:1:1 on bacterial profile and biogenic amine accumulation in Chinese Sichuan sausages were demonstrated.In starter culture-inoculated sausages,Lactobacillus spp.,Pediococcus spp.and Staphylococcus spp.were predominant bacterial genus and their relative abundances ranged from 70.14%to 25.98%,57.66%to 14.08%,and 15.71%to 13.40%during fermentation,respectively.Accordingly,Lactobacillus spp.and Weissella spp.were predominant bacterial genus and their relative abundances ranged from 63.14%to 24.70%and 49.40%to 11.96%during spontaneous fermentation,respectively.Furthermore,the abundances of undesirable microorganisms such as Yersinia spp.,Enterobacter spp.,Acietobacter spp.and Psychrobacter spp.were lower than that of the control.The levels of histamine,putrescine,tyramine and cadaverine in Chinese Sichuan sausages with starter cultures inoculation were significantly lower(P<0.05)than that of the control,and were decreased by 83.09%,69.38%,51.87%and 57.20%,respectively,at the end of the ripening.These results revealed that the starter cultures inoculation was a better alternative for microbial quality improvement and biogenic amine reduction of Chinese Sichuan sausages with good sensory attributes.

Isolation of Acetic Acid Bacteria and Preparation of Starter Culture for Apple Cider Vinegar Fermentation

Vinegars are commonly used as food condiments and preservatives. Apple cider vinegar (ACV) is also used in the Ayurvedic pharmaceutical industry because of its medicinal properties. Since specifically selected starter cultures for commercial vinegar production are not readily available, apple juice supplemented with sugar is commonly inoculated with a microbiologically undefined culture obtained from the previous batch of ACV. The present work focuses on the isolation of yeasts and acetic acid bacteria from ACV and the preparation of a starter culture. ACV was produced in a bench scale bioreactor using a traditional fermentation process wherein an acetic acid concentration of 3.8% was obtained after three weeks. Several acetic acid bacteria (AAB) were isolated from ACV using selective media. Microscopy revealed the cultures to be gram negative to gram variable short rods. The growth pattern of the isolates on differential media and biochemical tests suggested the presence of Acetobacter and Gluconobacter species. Ten potent isolates were selected for starter culture preparation. Two consortia were formulated with five AAB isolates in each along with a yeast isolate and used for ACV production, wherein an acetic acid concentration of 4.2% - 4.9% was obtained in 10 - 12 days. Thus, these two starter cultures with locally isolated AAB can be used for the commercial production of apple cider vinegar.

Development of Starter Culture for the Production of African Condiments and Seasoning Agents

As a process, food fermentation dates back at least 6000 years and is likely to be derived from microbial interactions of an appropriate nature. Fermentation has allowed our ancestors to survive the winter season in temperate and cooler regions and those in the tropics to survive the periods of drought by improving food shelf-life and safety. Traditional fermentation process is still used as a replacement where there is no refrigeration or other means available for food storage. In general, fermented foods can be defined as foods produced through controlled microbial growth and the conversion of food components through enzymatic actions. They are generally appreciated for characteristics such as pleasant taste, aroma, texture and improved cooking and processing properties. Microorganisms contribute to the development of characteristic properties such as taste, smell, visual appearance, texture, shelf-life and protection by virtue of their metabolic activities. Enzymes indigenous to the raw materials may play a role in enhancing these characteristics. The use of starter cultures is a hallmark of industrial food fermentation and their introduction has been followed by a continuous search to improve them. Examples of desired properties in starter cultures include robustness during manufacturing, fast growth, high biomass yield and product yield and specific organoleptic properties. Quality, safety and acceptability of traditional fermented foods may be significantly improved through the use of starter cultures selected on the basis of multifunctional considerations, also taking into account the probiotic concept and possibilities offered for improved health benefits. Focused studies toward the introduction of starter cultures for small-scale fermentations seem more than justified, and in fact, deserve the highest priority.

Effect of Different Ratios of DL-type Starter Culture： Mould Geotrichum candidum on the Viscosity and Sensory Properties of Fermented Milk

A great variety of dairy products with different flavour, texture and health-promoting properties can be obtained from milk using different technologies and starter cultures. Fermented milks are consumed in many parts of the world and are relished for their acidic taste and health benefits. The aim of this study was to compare effects of different ratios of DL-type starter culture： mould Geotrichum candidum grown in milk on its viscosity and sensory properties on the 5th, 10th and 15th day of storage at 4 ~C~ in order to determine the best ratio to prepare fermented milk on basis of Iranian acceptance. We have examined the production of fermented milk by 80： 20, 70： 30, and 60：40 ratios of DL-type starter culture： mould Geotrichum candidum grown in milk. The results obtained from viscosity measurement and sensory evaluation showed no significant difference between these treatments used in the study and were not satisfactory; their viscosity was not accepted and scores attributed to odour and flavor of fermented milks by panelists were low.

食品发酵剂研究进展与发展趋势浅析

食品发酵剂能够通过多种代谢途径影响发酵食品的感官特性、营养价值和益生功能,是发酵食品生产制造的核心。优良性能食品发酵剂的挖掘与制造,对发酵食品产业的高质量发展具有重要意义。本文通过综合文献调研和数据可视化分析,系统梳理当前国内外食品发酵剂研究进展及产业现状,总结食品发酵剂产业面临的挑战并展望未来发展趋势,旨在为我国优良性能食品发酵剂的研发及产业发展提供思路和借鉴。

不同发酵剂对发酵牛肉品质、风味特性和安全性的影响

牛肉富含蛋白质、脂肪含量低,深受消费者喜爱,然而其难咀嚼、附加值低。为提高牛肉的口感风味,研究本单位的3株专利菌株——W9-3罗伊氏乳杆菌、M3-16副干酪乳杆菌和MY4马克斯克鲁维酵母制备的单菌和复配发酵剂对牛肉理化、感官品质、生物胺形成和挥发性风味的影响。结果表明,与未发酵和自然发酵的牛肉相比,添加发酵剂可降低牛肉的pH(均小于5.5)、水分活度(降低0.6%~4.1%)、TBA值和羰基值,抑制组胺、色胺、酪胺和丁二胺等生物胺的形成,提升熟化牛肉的亮度和弹性,降低硬度、黏着性、咀嚼性和黏聚性。其中复配组优于单菌组。利用SPME-GC-MS方法从焙烤发酵牛肉中鉴定出86种挥发性化合物,其相对含量和主成分分析结果表明,用发酵剂发酵的烤牛肉的风味物质与未发酵和自然发酵相比形成多种新的醇、醛和酮类。感官评价表明,使用发酵剂能在一定程度上提高牛肉的组织形态、外观色泽、气味和口感。尤其是复配发酵剂可改善发酵牛肉品质,提升风味,抑制生物胺。本文为牛肉发酵工艺优化提供理论依据。

Microbiological and Nutritional Assessment of Starter-Developed Fermented Tigernut Milk

Fermented tigernut milk (FTM) was prepared from three different varieties (fresh yellow, big and small dry brown) of tigernut (Cyperus esculenta) obtained from Bodija market, Ibadan, Oyo state. Fifty two microbial isolates were obtained from FTM at different fermentation times, 32 of which were on MRS agar, 12 on nutrient agar and 8 on malt extract agar. Lactic acid bacteria were identified as Lactobacillus plantarum (LP), Lactococcus lactis (LC), Lactobacillus brevis, Lactococcus cremoris, Lactobacillus bulgaricus and Lactococcus thermophilus (LT). The non-LAB identified includes E. coli, Bacillus species and Proteus species while the yeasts include Saccharomyces cerevisiae and Candida kefyr. Lactic acid bacteria were found to predominate the total microflora of the FTM with their count ranging between 2.0 × 104 cfu/ml to 2.0 × 108 cfu/ml. Microbiological examination revealed that the FTM was safe for consumption as non-LAB counts were below the limit of acceptance which is 2.0 × 105 cfu/ml for dairy milk by Codex Alimentarius Commission. The quantity of lactic acid produced by the LAB isolates ranged between 0.86 g/l - 2.86 g/l while that of hydrogen peroxide ranged between 0.16 g/l - 0.51 g/l. Starter cultures were selected based on predominance of isolate, physiological characteristics, quantity of lactic acid and hydrogen peroxide production. The tiger nut varieties were fermented with the following starter combinations LP, LP/LC, LP/LC/LT, LP/LT while the fifth was spontaneously fermented. The nutritional, chemical and sensory properties of the starter fermented tiger nut milk were evaluated. The highest protein content (24.80%) was obtained in FTM with mixed cultures of LP/LC/LT while the least (3.00%) was obtained in spontaneously fermented milk. There was a significant difference in the FTM varieties. The highest fat content (9.40%) was obtained in spontaneously fermented tiger nut milk while the least (3.40%) was found in FTM with mixed cultures of LP/LC/LT. Fermentation decreased the pH and increased the lactic acid of the starter developed FTM, while sensory evaluation test showed that the FTM with mixed cultures of LP/LC/LT was highly acceptable. In conclusion, an excellent and acceptable FTM can be produced using treatments which comprise of pasteurization at 90°?for 15 minutes, fermentation at 45℃?for 18 hours using mixed cultures of Lactobacillus plantarum, Lactococcus lactis and Lactococcus thermophilus.

复配发酵剂对发酵香肠的品质及挥发性风味的影响

为评判植物乳杆菌(L77)和木糖葡萄球菌(S120)复配发酵剂的优良特性,本研究以不接菌为空白对照组,采用顶空固相微萃取/气相色谱-质谱联用(HS-SPME/GC-MS)等技术分析比较了L77-S120组和L77组对发酵香肠的常规理化和微生物指标、主体挥发性风味化合物数量含量及香型、感官品质的影响。结果显示,L77-S120组的TBARS值、亚硝酸盐含量和肠杆菌数量均显著低于空白组和L77组(P<0.05);L77-S120组的主体挥发性风味物质的数量和含量最多,有10种醛类、3种醇类、2种酯类、1种酸类,4种其他类,差异风味化合物包括庚醛、(E)-2-庚烯醛、蘑菇醇、2-戊基呋喃、反-2-辛烯醛、反-2,4-癸二烯醛、反-2-十一烯醛、2-乙基丁酸、癸酸乙酯、戊醛和壬醇,并且主体挥发性风味物质产油脂香、奶油香和花果香的能力最强。结合感官评价,植物乳杆菌L77和木糖葡萄球菌S120复配组合更适合作为发酵香肠的产香型发酵剂。

玉米品种和发酵剂对全株玉米青贮营养品质的影响

本试验旨在探究不同玉米品种和发酵剂对全株玉米青贮营养品质的影响,筛选出最优发酵剂和最适合甘肃中东部地区的青贮玉米品种。以“京科627”(H1)、“金穗1915”(H2)、“铁研53”(H3)、“登海3721”(H4)、“大京九26”(H5)、“陇青贮1号”(H6)6个玉米品种为试验材料,在蜡熟期收获,分别添加以植物乳杆菌、乳酸片球菌等为主的饲草青贮剂1(A1)、以布氏乳杆菌9-2和戊糖片球菌为主的饲草青贮剂2(A2)和以植物乳杆菌A1和植物乳杆菌LP-21为主的饲草青贮剂3(A3)3种发酵剂并设置空白对照组(CK),共24个处理,每个处理3个重复。发酵90 d后测定其品质。结果表明:玉米品种对干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)、乳酸(LA)、乙酸(AA)、丙酸(PA)、氨态氮(NH 3-N)含量以及中性洗涤纤维消化率有极显著影响(P<0.01);与空白对照组相比,3种发酵剂显著提高了DM、CP、LA、AA含量(P<0.05),极显著降低了NH 3-N含量(P<0.01)。综上所述,3种发酵剂对不同品种全株玉米青贮的品质有不同程度的提升,灰色关联度分析结果表明以“饲草青贮剂3”处理的“登海3721”为最优组合,最适合在临夏地区种植和推广应用。

霉菌发酵剂的制备及其对干腌肉块品质的影响

以干腌肉块作为宣威火腿的模拟体系,探讨6组霉菌发酵辅助剂对其物理化学特性和风味品质的影响。在6组发酵辅助剂中,鲁本斯青霉W10-1+褐藻青霉V8展现出了最高的中性、酸性蛋白酶和脂肪酶酶活性。将发酵辅助剂接种至干腌肉块中,发现相较于自然发酵组,接种霉菌均能提高干腌肉块的水分活度、pH、蛋白降解指数,且能使其维持在干腌肉制品的最佳范围内;此外,能增加挥发性风味化合物的种类并降低醛类物质的含量,改善亮度和红度,降低剪切力和硫代巴比妥酸值。其中,W10-1+V8组表现最为优异。电子鼻分析表明,W10-1+V8组与自然发酵组的风味特性最为接近,还能缓解脂质过度氧化。电子舌分析表明,W10-1+V8组在鲜味、丰富度上显著高于自然发酵组,酸味显著低于自然发酵组。因此,鲁本斯青霉W10-1+褐藻青霉V8最适宜作为干腌肉制品的发酵剂,为提升宣威火腿的品质提供技术支撑。

六堡茶真菌固态发酵优势单菌的筛选

以苍梧群体种六堡毛茶为原料,利用从六堡茶中分离到的20株真菌接种至灭菌六堡毛茶进行固态发酵,通过感官审评、生化成分检测结合主成分分析,探索不同真菌的发酵效果,筛选出可显著提升六堡茶品质或赋予六堡茶新风味的固态发酵优势真菌。结果显示,9株真菌发酵性能优异,分别为塔宾曲霉、黑曲霉、芒果青霉、角膜曲霉、赤曲霉、间型曲霉、团青霉、阿姆斯特丹曲霉、赤酵母。对9株真菌发酵茶样进行理化成分分析,结果显示:接种塔宾曲霉、黑曲霉、团青霉和阿姆斯特丹曲霉发酵能显著改变茶叶中18种化学成分的含量。综合考量确定团青霉和阿姆斯特丹曲霉为发酵优良真菌。本研究可为后期人工控菌发酵六堡茶提供优良菌种资源,并为六堡茶发酵工艺改良、产品研发创新及品质提升提供科学的理论依据。

不同发酵剂对木薯茎叶青贮品质的影响

试验探究了不同发酵剂对木薯茎叶青贮品质的影响。试验分为对照组(CK组)和3个处理组(A组、B组、C组)。CK组中不添加任何发酵剂,3个处理组在木薯茎叶原料中分别添加0.02%的发酵剂A、发酵剂B、发酵剂C,每组3个重复,发酵90 d后取样分析。结果表明,各处理组的干物质、Ca、P含量与CK组无明显变化;C组粗蛋白、粗脂肪、粗灰分含量均最高,分别较CK组升高8.06%、17.84%、2.01%;A组木质素含量最低,较CK组降低14.43%;C组中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、可溶性碳水化合物(WSC)含量均最低,分别较CK组降低11.40%、16.62%、14.96%。各处理组的所有饲喂价值指标均高于CK组,C组的所有饲喂价值指标均最高。B组pH值、氨态氮、丁酸和氨态氮/总氮的数值均最低,较CK组分别降低8.88%、20.90%、99.48%和26.82%;C组乳酸含量最高,较CK组升高26.03%;A组乙酸含量最低,较CK组降低5.85%。对发酵品质进行综合评分可知,各处理组得分均高于CK组。利用平均隶属函数值对木薯茎叶青贮品质进行综合比较,B组的青贮品质最佳。研究表明,添加微生物发酵剂在一定程度上能够改善木薯茎叶的青贮品质。

不同乳酸菌接种发酵对泡白菜理化特征及风味的影响

为评估泡白菜中乳酸菌的发酵特性,以植物乳杆菌(Lactobacillus plantarum)PC295、肠膜明串珠菌(Leuconostoc mesenteroides)PC137、柠檬明串珠菌(Leuconostoc citreum)PC222、食窦魏斯氏菌(Weissella cibaria)PC311、清酒乳杆菌(Lactobacillus sakei)PC229、短乳杆菌(Lactobacillus brevis)PC330为发酵菌株,分析不同乳酸菌接种发酵对泡白菜pH、总酸、还原糖、微生物数量、有机酸、游离氨基酸、挥发性风味成分的影响。经6种乳酸菌接种发酵后,泡白菜的pH、还原糖、柠檬酸、苹果酸、游离氨基酸总量以及大肠杆菌数量均下降;不同种乳酸菌表现出不同的发酵性能,植物乳杆菌PC295和短乳杆菌PC330发酵速度快,还原糖消耗量和产酸量高,抑制大肠杆菌效果好;异型发酵菌株产较多的乙酸和乙醇。采用顶空固相微萃取-气相色谱-质谱联用技术共检出挥发性风味物质56种,所有泡菜组均以醇类化合物为主,主要包括乙醇、1-辛烯-3-醇、顺-2-戊烯-1-醇等;清酒乳杆菌PC229和短乳杆菌PC330发酵的泡白菜中,反,反-2,4-庚二烯醛、己醛等醛类化合物和乙酸的相对含量高于其他组;主成分分析结果显示,肠膜明串珠菌PC137和柠檬明串珠菌PC222发酵的泡白菜成熟后其挥发性风味相似。不同种乳酸菌在泡白菜发酵速度、风味类型和底物消耗上存在差异。研究结果为进一步开发白菜类泡菜发酵剂奠定了基础。

复合菌发酵对非油炸方便面品质的影响

通过酵母菌、保加利亚乳杆菌、嗜热链球菌发酵制备非油炸方便面,通过复水测试、质构分析、电子鼻分析、扫描电子显微镜观察等探讨复合菌发酵工艺对非油炸方便面品质的影响。结果表明,酵母菌主要对样品的复水性和质构产生影响,保加利亚乳杆菌、嗜热链球菌主要对风味起到改善作用。一次发酵工艺有利于维持非油炸方便面的耐泡性,二次发酵工艺有利于改善复水性和风味。经过二次发酵,非油炸方便面的最佳复水时间可缩短到4.0 min,复水后样品的R(2)、R(7)的响应值高达2.8和2.9。由扫描电子显微镜观测结果可知,复合菌发酵能够赋予非油炸方便面疏松多孔的内部结构,其中二次发酵样品的孔隙分布更为均匀。综合评价非油炸方便面的品质,一次发酵、二次发酵工艺中复合菌的适宜添加量均为1.5%酵母菌+0.075%保加利亚乳杆菌+0.075%嗜热链球菌。

不同发酵剂对发酵驴乳酸奶在冷藏期间品质的影响

目的研究不同发酵剂对发酵驴乳酸奶在冷藏期间品质的影响。方法对3种发酵剂发酵的驴乳酸奶在冷藏期间微生物指标、理化指标和感官品质进行检测分析。结果用市售酸奶A发酵的驴乳酸奶LR-A在冷藏的1~26 d中乳酸菌活菌数由69.33×10^(7)CFU/mL下降至0.50×10^(7)CFU/mL,用市售酸奶B发酵的驴乳酸奶LR-B冷藏前7 d乳酸菌活菌数显著下降(P<0.05),7 d后又逐渐上升,而用传统酸奶C发酵的驴乳酸奶LR-C在冷藏过程中乳酸菌活菌数一直呈上升趋势;3种发酵剂发酵的驴乳酸奶在冷藏第14d时细菌菌落总数均达到最高值,持水力在冷藏前14 d均呈现下降趋势,总体口感较佳,LR-C冷藏第7~26 d的持水力均高于LR-A和LR-B;随冷藏时间的延长,pH整体呈下降趋势(LR-B>LR-A>LR-C),总酸度值的变化趋势与pH相反(LR-C>LR-A>LR-B)。结论不同发酵剂对发酵驴乳酸奶在冷藏期间品质影响差异较大,LR-A和LR-B在冷藏至26 d时仍可饮用,LR-C在冷藏14 d后因酸度太高,超出可接受范围。

肉品发酵剂及其对肉制品影响的研究进展

发酵是加工贮藏肉类的方法之一,是指微生物在特定条件下将有机物转化为代谢产物并释放能量的过程。发酵肉制品营养丰富、风味独特,深受消费者喜爱。早期自然发酵产品品质稳定性差,易引发安全问题;肉品发酵剂的使用能够提高肉制品的品质和安全性,极大缩短产品的生产周期。本文综述肉品发酵剂菌种的来源、种类及其研究现状,探究微生物对肉制品中碳水化合物、蛋白质、脂肪及生物胺的影响,展望肉品发酵剂的应用前景,为肉品发酵剂的研究应用提供理论参考。

Contribution of mixed commercial starter cultures to the quality improvement of fish-chili paste,a Chinese traditional fermented condiment

This study evaluated the effects of commercial starter cultures on the microbial counts,protein degradation,biogenic amines and volatile compounds in fermented fish-chili paste.Four inoculated groups with different starter cultures and one group without inoculation were investigated.The results revealed that the application of mixed starter cultures promoted the growth of lactic acid bacteria and yeast,while effectively inhibited the Enterbacteriaceae counts compared with the spontaneously fermented group.The inoculation with mixed starter cultures resulted in higher levels of umami-tasting free amino acids(FAAs)in all inoculated groups.Highest content of sweet-tasting FAAs was found in group HS(Pichia anomala+Staphylococcus xylosus+Staphylococcus carnosus+Pediococcus pentosaceus+Pediococcus acidilactici),and much lower bitter-tasting components were presented in group HW(Pichia anomala+Staphylococcus xylosus+Staphylococcus carnosus),HS and HV(Pichia anomala+Lactobacillus plantarum).In addition,total levels of biogenic amines detected in all inoculated samples were significantly lower compared with control,especially the content of tyramine(P<0.05).For the volatile compounds,more esters as well as less undesirable odor substances such as aldehydes,were exhibited in four inoculated groups.