应用复合发酵剂加工发酵干香肠过程中的理化及微生物特性

本文揭示了发酵干香肠生产过程中水分活度、pH值、酸价、过氧化物值、蛋白水解指数等理化指标及微生物指标的变化情况。研究表明,添加发酵剂的产品比自然发酵产品的pH值、水分活度、水分含量下降得更快,蛋白水解指数更大,风味更好,并明显抑制杂菌的生长;但两类产品最终具有相同的乳酸菌数、酸价和过氧化物值。这说明在发酵干香肠的加工过程中,产品pH值、水分含量、水分活度、蛋白水解程度等受发酵剂种类的影响,而脂肪氧化程度与发酵剂关系不大。     

木糖葡萄球菌和肉葡萄球菌混合发酵剂对腊肉品质的影响

以不添加发酵剂的腊肉为空白对照,从理化特性、微生物分析、感官评价、香气活性化合物组成及电子鼻分析角度,研究木糖葡萄球菌和肉葡萄球菌混合发酵剂对腊肉品质的影响。结果表明,添加葡萄球菌混合发酵剂对产品的品质影响较大。与空白组比,葡萄球菌混合发酵剂可显著提高产品的酸价（2.12→3.28?mg/g）、蛋白质降解指数（16.32%→19.24%）、红度值a*（9.25→11.08）、香气和接受度得分及氨基酸代谢源香气活性化合物的种类和含量（3-甲基丁醛、3-甲基丁酸）,同时显著降低产品的过氧化值（0.15→0.07?g/100?g）、硫代巴比妥酸反应物含量（0.25→0.17?mg/kg）和脂肪氧化源香气活性化合物的含量（己醛和壬醛）,而对成品的基本理化指标（水分含量、水分活度、pH值）没有显著影响。电子鼻传感器能够将2?组产品区分开,说明加入发酵剂后,腊肉的风味有所改变。因此,通过添加木糖葡萄球菌和肉葡萄球菌混合发酵剂可以显著促进腊肉中蛋白质和脂肪的水解、改善产品的色泽,促进发酵风味快速形成,同时延缓脂肪氧化。     

直投式发酵剂制备的哈尔滨风干肠在成熟过程中的理化及微生物特性变化

采用三种由自然发酵分离鉴定出的微生物,按一定比例混合制备复合发酵剂,将其用于哈尔滨风干肠中,研究其对风干肠的理化性质、微生物变化和游离氨基酸含量的影响。实验分为三组,分别为对照组,添加普通发酵剂组和添加直投式发酵剂组。结果表明:添加发酵剂的风干肠pH明显低于对照组,且添加直投式发酵剂的pH最低(P<0.05);添加发酵剂会使产品的游离氨基酸含量显著提高(P<0.05)、感官品质也较好(P<0.05),而各组水分活度变化差异不明显,这说明直投式发酵剂具有很好的活力和发酵性能,能够显著提高风干肠的质量,缩短发酵时间。     

不同发酵方式对发酵马肉肠贮藏期品质劣变及食用安全性的影响

为有效确保发酵马肉肠贮藏期间的品质及安全性,研究添加汉逊德巴利酵母菌1808（Debaryomyces hansenii 1808）、木糖葡萄球菌21445（Staphylococcus xylose 21445）、植物乳杆菌E11（Lactobacillus plantarum E11）的复合发酵剂发酵组（FP）和单一乳酸菌发酵组（DZ）、自然发酵组（ZR）马肉肠贮藏过程中生物胺的变化,考察不同发酵方式对发酵马肉肠pH值、水分活度（aw）、色差、总挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARs）值及菌落总数的影响。结果表明：在贮藏期间,相比于自然发酵组和单一乳酸菌发酵组,添加复配发酵剂可有效减缓发酵马肉肠TVB-N含量、TBARs值、pH值的增幅,抑制贮藏后期有害杂菌的生长,防止产品过早发生腐败变质;此外,复配发酵剂可显著降低贮藏过程中马肉肠的水分损失（P＜0.05）,维持色泽的稳定,抑制生物胺（尸胺、腐胺、酪胺、组胺）的积累。综上,随着贮藏时间的延长,复配发酵剂可显著抑制发酵马肉肠品质的劣变及不良生物胺的过多积累。     

接种发酵剂对哈尔滨风干肠中生物胺形成的抑制作用

研究了接种植物乳杆菌、弯曲乳杆菌、发酵乳杆菌和木糖葡萄球菌对风干肠发酵过程中生物胺形成的抑制作用,以及其对风干肠发酵过程中理化指标(pH、水分含量、水分活度、硫代巴比妥酸值)、微生物指标(总好氧菌数、乳酸菌数、肠杆菌数)及感官品质的影响。研究表明:植物乳杆菌和木糖葡萄球菌可以显著降低生物胺(酪胺、腐胺、尸胺、组胺、2-苯乙胺和色胺)的积累(P0.05),并促进风干肠pH的降低,抑制肠杆菌增长和硫代巴比妥酸值的增加,同时还可促进风干肠风味的形成,改善风干肠的感官品质。     

多羟基醇对发酵香肠加工过程中理化性质及感官品质的影响

研究了不同山梨糖醇添加量下,发酵香肠加工过程中主要理化性质及感官品质的变化情况。结果表明山梨糖醇添加量≤8%时,发酵剂产酸能力与对照组无显著差别,而添加量≥10%时,发酵剂产酸能力受到一定程度的抑制;发酵香肠加工过程中,水分活度逐渐降低,山梨糖醇的加入可以增大发酵香肠水分活度的降低幅度;当保持最终产品水分活度为0.85时,添加山梨糖醇组的发酵香肠水分含量均显著高于对照组(p<0.05)。加工过程中发酵香肠非蛋白氮含量、蛋白降解指数和氨基态氮含量逐渐升高;与对照组相比,山梨糖醇添加量≥4%时蛋白降解程度显著降低(p<0.05)。相关性分析表明发酵和烘烤过程中,山梨糖醇添加量分别与PI值和Aw呈极显著负相关,与pH呈极显著正相关(p<0.05)。而感官分析表明不同添加量下产品的滋味和香味并无显著差别,山梨糖醇添加量≥4%时可以改善产品的口感,山梨糖醇添加量4%~8%时产品总体可接受性较高。     

不同产蛋白酶乳酸菌对风干牛肉品质影响及安全性评价

为提升风干牛肉的品质，筛选具有优良特性的乳酸菌发酵剂进行风干牛肉的制作。分别将3种产蛋白酶乳酸菌（乳酸乳球菌（S-1）、戊糖片球菌（S-2）、格氏乳球菌（S-3））接种于牛肉，研究牛肉腌制、发酵、风干、成熟等不同阶段的水分、pH、硫代巴比妥酸（TBARS）值、色泽、质构和微生物等品质指标变化。另外，采用高效液相色谱法分析样品中生物胺质量分数变化，并对添加的菌株安全性进行评价。结果表明，3种产蛋白酶乳酸菌均可以显著降低风干牛肉的pH和TBARS值(P＜0.05)，改善色泽和质构，但对水分质量分数变化没有显著影响（P＞0.05）；3种发酵剂均能有效抑制产品中大肠菌群的生长，其中S-2抑菌作用最强；3种发酵剂均可以有效抑制风干牛肉中生物胺（腐胺、尸胺、组胺、酪胺）的形成，其中S-2、S-3的抑制效果更好。因此，3株乳酸菌作为发酵剂应用于风干牛肉可以提升产品品质及安全性，可以为产蛋白酶乳酸菌在风干牛肉中的应用提供理论依据。     

猕猴桃蛋白酶及发酵剂对马肉发酵香肠品质特性的影响

研究发酵剂和猕猴桃蛋白酶对马肉发酵香肠品质的影响。以新鲜马肉为原料,添加发酵剂和猕猴桃蛋白酶进行发酵,检测其对马肉发酵香肠pH值、水分活度（water activity,aw）、水分含量、色差以及硫代巴比妥酸（thiobarbituric acid,TBA）值等的影响,并通过对成品进行感官评价确定发酵剂和猕猴桃蛋白酶对其感官品质的影响。结果表明：与对照组相比,发酵剂处理组（A组）显著降低了马肉发酵香肠的pH值、aw和TBA值,加快了水分含量的下降,提高了亮度值（L*）和红度值（a*）,后期黄度值（b*）略有下降;与A组相比,发酵剂和猕猴桃蛋白酶处理组（B组）提高了其pH值,降低了aw,加快了水分含量的下降,而对a*、L*、b*影响不大,对TBA值无显著影响;对成品的感官评价结果表明,B组马肉发酵香肠的口感较A组和对照组好。     

复合发酵剂对发酵牛肉干理化品质及安全性能的影响

以清酒乳杆菌、戊糖片球菌及木糖葡萄球菌为复合发酵剂（1:2:2）制作发酵牛肉干,通过色差计及高效液相等仪器测定不同阶段牛肉干的pH、水分活度、色泽及生物胺含量等指标的变化,旨在探究复合发酵剂对发酵牛肉干理化品质和生物胺组成的影响。结果表明:接种上述复合发酵剂促使肉干中乳酸菌快速成为优势菌群,加快产品酸化速率,发酵结束时清酒乳杆菌+戊糖片球菌+木糖片球菌复合发酵剂组（LSS组）pH降为4.43,显著低于对照组（CO组）（P<0.05）;pH的快速下降促进肉干中水分快速蒸发和Aw的降低,显著抑制了肉干中肠杆菌的数量,使得LSS中肠杆菌数量降低到2.04 CFU/g。复合发酵剂的快速繁殖抑制了肉干中腐胺和尸胺的积累,LSS组尸胺和腐胺含量显著低于CO组（P<0.05）。随着加工温度和优势菌群数量的变化,对组胺产生较大抑制作用,使添加复合发酵剂的LSS组组胺含量（22.56 mg/kg）仅为CO组的1/2。因此,添加上述复合发酵剂有利于缩短发酵牛肉干加工周期、提高产品品质和安全性能。     

贵州酸肉中的植物乳杆菌对发酵香肠风味和品质特性的影响

本文研究了贵州酸肉中分离出的2株植物乳杆菌CMRC3和CMRC19,分别作为单一菌株发酵剂时,对发酵香肠微生物、理化性质、挥发性风味和感官品质的影响。结果表明,与未添加发酵剂的对照香肠相比,添加发酵剂的香肠中乳酸菌数量增加较快,肠杆菌数量显著降低,保证了产品的食用安全性。添加发酵剂降低了香肠的水分活度,有利于延长保质期。同时,添加发酵剂的香肠的质构变化显著。利用SPME-GC/MS技术从发酵香肠中鉴定出50种挥发性风味物质,主要包括萜烯类、酸类、醇类、醛类和酯类。感官评价表明,添加发酵剂的香肠气味、滋味和总体可接受性评分高。结论:从贵州传统酸肉中分离出的2株乳酸菌可开发成肉类专用发酵剂。     

接种植物乳杆菌和戊糖片球菌发酵对鱼鲊品质的影响

以白鲢为主要原料制作鱼鲊,研究自然发酵及接种植物乳杆菌和戊糖片球菌发酵对鱼鲊化学指标和感官品质的影响,以确定鱼鲊合理的接种发酵条件。结果表明,发酵可促进鱼肉中蛋白质的水解,提高鱼鲊中水溶蛋白含量、水溶性固形物含量和总酸含量,降低pH,产生较多的游离氨基酸,改善鱼鲊的感官品质。接种发酵可改善鱼鲊游离氨基酸的组成,提高鱼鲊的感官品质,接种复合乳酸菌(植物乳杆菌:戊糖片球菌=10:1,106CFU/g)发酵60h的鱼鲊的感官品质最高。     

1 株高效降胆固醇乳酸菌的功能与发酵特性

通过研究乳酸菌X3-2B降胆固醇功能特性以及在发酵香肠中的发酵特性,确定高效降胆固醇性能的肉制品发酵剂。结果表明：菌株X3-2B在培养温度为30 ℃、pH 5.5时胆固醇降解率最大,在MRS胆固醇筛选培养基中其胆固醇降解率最大且优于标准菌株植物乳杆菌（L. plantarum,LP）。并以菌株X3-2B为发酵剂做的发酵香肠其水分活度、pH值在相同天数时下降程度显著优于自然发酵组（P＜0.05）,色泽、乳酸菌数都优于对照组,且发酵香肠14 d与0 d相比,添加发酵剂的发酵香肠胆固醇含量显著降低（P＜0.05）且在贮存56 d时X3-2B组发酵香肠胆固醇含量低于自然发酵组与LP组,故菌株X3-2B可作为一株降胆固醇性能较好的肉制品发酵剂。     

Role of surface-inoculated Debaryomyces hansenii and Yarrowia lipolytica strains in dried fermented sausage manufacture. Part 2: Evaluation of their effects on sensory quality and biogenic amine content

The aim was to study the effects of Debaryomyces hansenii and Yarrowia lipolytica strains, used with lactic acid starter cultures (Lactobacillus plantarum), in the manufacture of dried fermented sausages in order to understand their effects on volatile profile, biogenic amine content and sensory properties. The experimental data showed that every yeast strain produced a specific profile of volatile metabolic products. The yeasts also gave sausages with distinctive sensory properties. The degree of mincing also influenced these properties, but none of these factors had significant influence upon the accumulation of biogenic amines.     

乳酸菌接种发酵对大头菜品质的影响

对大头菜进行乳酸菌接种发酵,研究乳酸菌对大头菜感官指标、理化指标及微生物指标的影响,并探讨接种发酵大头菜的硬度与果胶变化的相关性。结果表明,添加乳酸菌对产品的感官性质和微生物指标具有显著的影响,可以改善产品的香气和滋味并有效降低大肠菌群含量;对产品的总酸、亚硝酸盐、咀嚼性、黏性、还原糖、氨基酸态氮、VC、硬度和果胶含量都有显著的影响,而对产品的色泽、弹性和内聚性影响不大。因此,通过添加乳酸菌,3 个月即达到出坛标准,感官评分达到94.0 分,亚硝酸盐和大肠菌群含量分别为1.43 mg/kg和＜30 MPN/100 g。可以明显缩短产品的生产周期,提高产品品质及安全性。乳酸菌接种发酵大头菜过程中硬度与原果胶成显著正相关,与水溶性果胶成负相关,但相关性不显著,说明其质构特性的变化机理更加多样和复杂。     

Effectiveness of a Lactobacillus sakei starter culture in the reduction of biogenic amine accumulation as a function of the raw material quality

The effectiveness of an amine-negative starter culture (Lactobacillus sakei CTC494) in the reduction of biogenic amine production during the ripening of fermented sausages was examined. Four batches were manufactured in parallel: spontaneously fermented and starter-mediated sausages were manufactured from two lots of raw materials of different hygienic quality. Besides the biogenic amine contents, changes in the microbial counts, nitrogenous fractions, pH, and water content were measured at several sampling points during the ripening process. In sausages manufactured from good quality meat, the starter strain of L. sakei reduced and even inhibited biogenic amine accumulation during sausage fermentation, the end products showing extremely low biogenic amine contents (tyramine levels less than 15 mg/kg of dry matter and putrescine and cadaverine levels less than 5 mg/kg of dry matter). Nevertheless, starter-mediated sausages made from poorer-quality raw materials showed much higher amine contents (308, 223, and 36 mg/kg of dry matter of cadaverine, tyramine, and putrescine, respectively), which were only slightly lower than those of the spontaneously fermented sausages made from the same raw materials. The relatively high bacterial numbers of raw materials of poorer-hygienic quality diminished the beneficial effect of the starter strain. Therefore, the effectiveness of the starter was strongly dependent on the hygienic quality of the raw materials used.     

Effect of proteolytic starter cultures of Staphylococcus spp. on biogenic amine formation during the ripening of dry fermented sausages

The effect of proteolytic starter cultures of Staphylococcus carnosus and Staphylococcus xylosus on biogenic amine production was examined during the fermentation process of dry sausages. Microbial counts (lactic acid bacteria, Micrococcaceae and Enterobactenaceae), pH, moisture and proteolysis-related parameters were also studied. The polyamines spermine and spermidine were the main amines found in the raw material and they only showed slight fluctuations during the fermentation. The four elaborated batches presented a significant (P < 0.001) formation of tyramine and putrescine. The main rate of amine production was during the first three days, when a sharp pH decrease and the development of lactic acid bacteria occurred. Sausages fermented with starters had lower amounts of tyramine than naturally fermented sausages (control), but differences in the Micrococcaceae counts were only significant during the first week of the ripening process. A slight formation of diaminopropane, cadaverine, agmatine, tryptamine and phenylethylamine was observed. The amounts of histamine were constant and remained below 0.5 mg/kg of dry matter, while serotonin, octopamine and dopamine were not detected. The sausages with Staphylococcus as starter culture showed strong proteolysis that was correlated with higher pH values than those of the control sausages. However, no positive correlation was found between the proteolysis index and biogenic amine production. Since proteolysis was stronger during the second half of the ripening process, the release of free amino acids as amine precursors occurred later than the early amine production.     

黄酒前酵中生物胺生成规律的研究

本研究对黄酒前酵工序的生物胺生成规律及影响因素进行了分析探讨。采用反相高效液相色谱技术,改进了生物胺定量检测法,该检测体系准确可靠,样品峰型对称分离度好且缩短了检测时间。分析了前酵工序中主要微生物,氨基酸,发酵醪酸度、糖度、酒精度、p H对生物胺生成的影响。发现前酵工序对成品酒生物胺的影响度为77.67%,第一次开耙阶段生物胺总量增幅最大,达到7.63 mg/L。研究发现主要酿造微生物中乳酸菌总数与生物胺总量成正相关,乳酸菌在搭窝期间生长速率最大,为7.13×106CFU/(m L·h)。在前酵工序中生物胺总量与发酵醪酸度、酒精度、p H呈显著正相关,与糖度呈负相关;前酵过程中主要生物胺与前体氨基酸也呈明显正相关。本研究分析了黄酒前酵中生物胺生成规律,有助于建立降低黄酒生物胺含量的更安全、科学的工艺。     

Use of Fourier transform infrared spectroscopy to evaluate the proteolytic activity of Yarrowia lipolytica and its contribution to cheese ripening

The interaction between tyrosine-decarboxylase and proteolytic activities of a Lactobacillus curvatus and Staphylococcus xylosus, respectively, on biogenic amine production during the ripening and the storage of dry fermented sausages was investigated. Water content, pH, proteolysis parameters, microbial counts, and biogenic amine contents were monitored in spontaneously and starter fermented sausages. The use of proteolytic staphylococci as starter resulted in a higher content of non-protein nitrogen and total free amino acids. Tyramine was the main amine produced in all batches. However, tyrosine-decarboxylase activity of the L. curvatus starter strain was weak and yielded lower amounts of tyramine than those produced by the wild mioroflora in the control batch. Association between tyramine production and proteolysis could only be established in a defectively dried batch. Putrescine and cadaverine accumulation was efficiently reduced in the starter-mediated fermentation, in agreement with the lower development of enterobacteria. Phenylethylamine and tryptamine were only detected in the spontaneously fermented sausages, while histamine, spermine and spermidine did not vary during the ripening. Biogenic amine levels and related parameters showed significant changes during the storage of dry sausages depending on the temperature and the batch. As a general rule, changes in the pH, proteolysis, microbial counts, and biogenic amine contents were stronger at 19 degrees C than at 4 degrees C. The results suggest that refrigeration would be advisable for preventing further accumulation of biogenic amines during the storage of dry fermented sausages.     

生物胺对啤酒质量的影响

生物胺是一类含氮的脂肪族或杂环类低分子化合物。啤酒中的生物胺与原料质量、酿造工艺及酿造和贮藏过程中受微生物污染程度、卫生条件密切相关。啤酒中常见的生物胺有酪胺；啤酒酿造过程产生适量色胺、尸胺、组胺，能改善啤酒风味，提高啤酒质量。啤酒中生物胺受底物氨基酸含量、生物胺产生菌、pH值的影响。控制生物胺的方法有限定麦汁中氨基酸含量；加强卫生管理，防止染菌；适当添加抑制剂。     

葡萄酒中生物胺含量的影响因素研究

研究了葡萄酒生产过程中影响生物胺产生量的主要因素,结果表明,葡萄酒酒精发酵和苹果酸．乳酸发酵过程均有牛物胺的产生,影响葡萄酒中生物胺产生的主要因素是乳酸菌中氨基酸脱羧酶的活性,本研究添加了氨基酸脱羧酶辅酶的样品与对照相比,生物胺含量提高了90．6％。酵母菌和乳酸菌种类、酒精发酵温度,生物胺前体物质也是影响生物胺含量的主要因素,发酵温度越高、生物胺产生量越;在一定范围内,氨基酸的浓度越大产生物胺越多。但酵母菌和乳酸菌的添加量对生物胺浓度的影响较小。