Effects of fermentation conditions on physicochemical properties and flavor quality of fermented bayberry juice

Probiotic fermented fruit juice could improve intestinal health with better sensory attributes.The effects of fermentation conditions on flavor quality of fermented bayberry juice were compared through microbial viability and sensory evaluation.Fermentation by combined Streptococcus thermophilus(ST)and Lactobaillus acidophilus(L A)resulted in higher microbial viability and sensory evaluation scores.The fermentation con-ditions were optimized by orthogonal experimental design and Technique for Order Preference by Similarity to an Ildeal Solution analysis(ST and LA in a mass ratio of 3:1;0.6%(mass concentration)inoculation;fermentation time,48 h,at 37℃;10%(mass concentration)added sucrose).Fermentation under these conditions decreased the anthocyanin content of the juice,maintained the total phenolic content,and slightly de-creased the antioxidant capacity.Fermentation reduced aroma volatiles from 42 in fresh juice to 33,as determined by gas chromatography-mass spectrometry-olfactometry(GC-MS-O),the aldehyde content decreased and the alcohol content increased.Lactic acid fermented bayberry juice by ST and LA produced a beverage with desirable consumer attributes,combining the health benefits of fresh juice and probiotics.

Effectiveness of Apricots (<i>Prunus armeniaca</i>), Pomegranate (<i>Punica granatum</i>) Juice and Lactic Acid Fermented Sobya on Plasma Levels of Lipid Profile Parameters and Total Homocysteine among Egyptian Adults

Objectives: The aim of this study was to investigate the effectiveness of dietary intervention with apricots, pomegranate juice or lactic acid fermented sobya on improving the plasma levels of lipid profile parameters and total plasma homocysteine (tHcy) among healthy adults. Design of the study: Thirty-five men and women (28.9 ± 3.0 years) with mean body mass index of 23.5 ± 1.2 kg/m2 were randomly assigned to a dietary intervention study. During the pre-feeding study records of 24-hour food intake, anthropometric measurements and blood sampling were collected for biochemical investigations. Thereafter the volunteers were divided into five groups: a control group (C);the other four groups received daily one of the following supplements: 200 g of deep yellow apricots (Prunus armeniaca) (AF);250 g pomegranate (Punica granatum) juice (PJ);mixture of 100 g (PJ) and 150 g of fermented sobya (FS), (PJ-FS) or 165 g (FS). After completing the three-week dietary intervention, blood samples were collected and blood indices were again evaluated. Biochemical analysis of total lipids (TL), total glycerides (TG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) and tHcy were completed. The low density lipoprotein-cholesterol level and three indices of risk factors were calculated using the appropriate equations. Results: Three-week dietary intervention improved the levels of lipid profile parameters TG, TC, HDL-C and LDL-C as compared to the respective baseline levels and the response of the control group that did not receive any supplement. Consuming (PJ-FS) had a synergistic beneficially added value on some of the above mentioned lipid profile parameters. The mean plasma tHcy concentrations;a marker for occlusive vascular disease was reduced significantly following the three week consumption of (PJ) or (FS), compared with the respective pre-feeding levels. Conclusion: Pomegranate juice (PJ) or lactic acid fermented sobya (FS) or mixture of both are potential natural agents in lowering the plasma levels of lipid profile parameters and tHcy among apparently healthy young women and men, without dyslipidemic symptoms.

Continuous Lactic Acid Production from Longan Juice by Lactobacillus casei subsp, rhamnosus TISTR 108

This research focused using novel substrate, longan Lactobacillus casei subsp, rhamnosus TISTR 108. The optimum juice as carbon source for continuous lactic acid production by medium for lactic acid production was pure longan juice with 120 g/L sugar concentration and among the different nitrogen sources were added to the longan juice （yeast extract, tryptic soy, urea, （NH4）2SO4 and NaNO3）, yeast extract had the most efficiency. Yeast extract （10 g/L） without adding minerals to longan juice could produced the maximum lactic acid concentration of 38.91 ± 0.190 g/L in 60 h and the yield of 0.460± 0.122 g/g with the productivity of 0.649± 0.002 g/Lh in 2 liters flask. Batch fermentation was conducted in 2 liters fermentor and 41.38± 0.030 g/L lactic acid was produced in 48 h with the yield of 0.398 ± 0.215 g/g and the productivity was 0.862 ± 0.001 g/L h. The continuous fermentation using 2 liters fermentor as a high productivity for lactic acid （1.091 ± 0.001 g/L h） was achieved at dilution rate （D） of 0.0685 h-1.

Unraveling the difference in flavor characteristics of dry sausages inoculated with different autochthonous lactic acid bacteria

The traditional dry sausage is highly appreciated in China because of its unique flavor characteristics.This study aimed to characterize and compare the flavor profile of traditional dry sausage,inoculated with lactic acid bacteria (LAB),including Lactobacillus plantarum MDJ2,Lactobacillus sakei HRB10,Lactobacillus curvatus SYS29,Weissella hellenica HRB6,and Lactococcus lactis HRB0 using headspace solid-phase microextraction gas chromatography-mass spectrometry coupled with electronic nose (E-nose).The control (non-inoculated) sausage presented higher water activity and moisture content compared to the inoculated sausages whereas,the inoculation led to decreased pH values and increased LAB counts during fermentation of dry sausages.Inoculation with LAB increased volatile compound contents and decreased total contents of free amino acids of sausages.E-nose and sensory analysis confirmed that inoculation with LAB,especially W.hellenica HRB6,Lb.sakei HRB10,and Lb.curvatus SYS29 enriched the pleasant odors of dry sausage.Correlation analysis demonstrated that sausages inoculated with W.hellenica HRB6 and Lb.sakei HRB10 showed a correlation with most of the key volatile compounds.In conclusion,W.hellenica HRB6 and Lb.sakei HRB10 are promising starter cultures to enhance the flavor characteristics of dry sausages.

超声波预处理对乳酸发酵草莓汁品质的影响

为提高乳酸发酵草莓汁品质,将不同功率(150、300、450 W)超声波应用于草莓汁乳酸发酵前处理环节,研究不同功率超声波处理对乳酸发酵草莓汁的营养及感官品质影响。结果表明:超声波处理能够显著地提高草莓汁中酚类物质含量,提高其抗氧化能力,改善乳酸发酵草莓汁的感官品质。其中,300 W超声波处理草莓汁经乳酸发酵后具有更低的色差值,更高的红色值、酚类物质含量及抗氧化活性,并且该产品具有更优良的感官品质。这表明超声波处理可以作为一种优良的前处理方式应用于草莓果汁的乳酸发酵,研究结果为提高草莓乳酸发酵果汁综合品质提供了理论依据。

传统酸菜发酵乳酸菌多样性及其功能特性研究进展

酸菜是以大白菜、卷心菜为主要原料,主要通过乳酸菌发酵而成的发酵食品,由乳酸菌发酵的酸菜具有独特的风味和积极的健康效果;乳酸菌也产生香气成分、细菌素和胞外多糖,这些成分有助于酸菜的质地、味道和保质期的提高;乳酸菌菌群结构交替变化,不同阶段发挥不同的作用,对酸菜品质、风味及安全性有很大的影响;酸菜富含蛋白质、碳水化合物、矿物质、维生素,因此食用酸菜有良好的益处;乳酸菌可以减少和降解酸菜中生物胺、亚硝酸盐和真菌毒素,从而降低了许多健康风险发生。基于此,本文综述了国内和国外酸菜乳酸菌的生化作用、多样性和益生性,乳酸菌分泌的代谢产物和风味,食用酸菜对健康的益处和酸菜存在的潜在风险,以期为传统发酵酸菜品质提升和筛选潜在益生菌菌株提供依据。

混合果汁发酵饮料的研制

以梨、苹果和葡萄为主要原料,研究复合乳酸菌发酵果汁生产工艺。首先确定护色条件和水果组合,再确定乳酸菌种类,然后用正交试验设计对发酵工艺进行优化,最后进行口味调配和组织稳定性的研究。结果表明,护色剂用0.4 g/100 mL抗坏血酸,苹果∶梨∶葡萄∶水配比为1∶2∶1∶5,保加利亚乳杆菌、嗜热链球菌和乳双歧杆菌为最适菌种组合,最佳发酵工艺条件为接种量1%,发酵温度35℃,发酵时间48 h,初始pH值6.5,蜂蜜添加量1.0%,白砂糖添加量1.5%,羧甲基纤维素钠(CMC-Na)、海藻酸钠、黄原胶添加量各0.04%进行口味和组织状态调配。制得的发酵果汁风味宜人,具有较好的营养和保健功能。

乳酸菌发酵饼干的品质特性

为研究乳酸菌发酵对饼干的蛋白质消化性和品质特性的影响,分别采用两种乳酸菌(植物乳杆菌DN-1、副干酪乳杆菌JN-1)与酵母共同发酵制备饼干,测定饼干的蛋白质体外消化率、蛋白质营养指标、品质和风味的变化。研究结果表明,与酵母单独发酵饼干(Control饼干)和市售梳打饼干相比,两种乳酸菌发酵饼干在胃肠消化阶段的蛋白质体外消化率均有所提高,其中在肠消化阶段DN-1饼干的蛋白质体外消化率最高,与酵母单独发酵饼干相比,其蛋白质体外消化率从81%提高至86%;同时,两种乳酸菌发酵饼干的硬度和脆性均有所降低;根据固相微萃取-气相色谱-质谱联用的测定结果可知,乳酸菌发酵饼干中酯类和醇类总相对含量和种类有明显的提高,与酵母单独发酵饼干相比,DN-1发酵饼干中酯类和醇类相对含量占比分别提高了335%、30%,其酯类物质和醇类物质的种类分别为26、24种。综上,乳酸菌发酵能提高饼干产品的蛋白质体外消化率,改善并丰富产品风味。

不同乳酸菌发酵燕麦浆的营养特性和风味品质分析

采用乳酸菌对燕麦进行生物加工,是改善燕麦风味、提升功能价值的新方法。但目前缺乏燕麦适配性发酵菌株,且未明确发酵燕麦的品质特征。该文评价了20株乳酸菌的性能,优选2株性能优良的植物乳杆菌,采用纯菌发酵及与牛乳发酵菌株嗜热链球菌和保加利亚乳杆菌组合的混菌发酵模式,对燕麦浆进行发酵,对比不同菌种组合发酵对燕麦浆理化指标和风味品质的影响。结果表明,植物乳杆菌普遍表现出较高的生长量、产酸性能及淀粉酶活性,且植物乳杆菌的淀粉酶活性均在7.69 U/mL以上。发酵燕麦浆活菌数均增加至10^(9)CFU/mL以上;发酵显著降低了燕麦浆中的还原糖,积累了有机酸,促进了多酚和黄酮的释放,提高了燕麦浆的抗氧化性;发酵增加了燕麦浆的持水力,产生了大量挥发性物质。植物乳杆菌有利于提高植物化学素含量和抗氧化性;添加嗜热链球菌和保加利亚乳杆菌的组中呈奶油香气的3-羟基-2-丁酮含量更高;植物乳杆菌F-嗜热链球菌L1-保加利亚乳杆菌L4组的感官品质、抗氧化性及风味品质最佳,是适宜发酵燕麦浆的菌种组合,具有更大的研究开发价值。

苹果汁发酵用乳酸菌WFC 414和WFC502的筛选·鉴定与评价

以泡菜为原料分离和筛选苹果汁中具有优良发酵潜力的乳酸菌(lactic acid bacteria,LAB)菌株,采用形态学、生理学和遗传学对LAB菌株进行鉴定,并评价其在模拟胃肠环境中的生存能力和发酵性能。结果表明:从泡菜中筛选的2株菌株为副干酪乳杆菌(Lactobacillus paracasei WFC 414)和植物乳杆菌(Lactobacillus plantarum WFC 502);WFC 414和WFC 502在苹果汁中发酵48 h其活菌数分别达到8.81和9.33 log CFU/mL;2种菌株在模拟胃液(2 h)和肠液(4 h)中,其存活率分别达到92.0%、95.0%和80.7%、83.6%。在4 d的乳酸发酵过程中,WFC 414和WFC 502降低了苹果汁中可溶性糖和苹果酸的含量,产生了大量的乳酸(分别为3.48、5.94 mg/mL)。发酵苹果汁挥发性香气成分改变,酯类和醛类减少,醇类、酸类和酮类的含量升高,增加了果汁的甜香、果香、花香味。试验筛选的乳酸菌WFC 414和WFC 502在发酵果汁行业有很好的应用潜力。

不同乳酸菌发酵对雪花梨汁营养成分、抗氧化活性及挥发性风味物质的影响

为提升雪花梨汁的抗氧化活性和风味,分别以干酪乳杆菌Y5-2b、植物乳杆菌C17和嗜酸乳杆菌CH-2制备发酵梨汁,对其理化指标和抗氧化活性进行分析,并采用高效液相色谱法和气相离子迁移谱技术(GC-IMS)对其营养物质和香气成分进行研究。结果表明:3株乳酸菌均能在梨汁中进行良好代谢,且Y5-2b和C17的增殖代谢表现更优,在20 h时活菌数达到稳定,增长至9.0 lg(CFU/mL);发酵梨汁的抗氧化活性显著升高(P<0.05);糖含量降低,其中葡萄糖消耗最多,利用率为5.29%~8.85%;部分有机酸含量呈现下降,在Y5-2b和C17组未检出苹果酸,CH-2组苹果酸含量与未发酵的含量无显著差异(118 mg/100 mL),且发酵后柠檬酸含量分别下降了33.65%,42.97%,38.71%;不同乳酸菌发酵对梨汁的酚类物质含量具有不同的影响,以熊果苷、儿茶素、芦丁含量变化为主;从梨汁样品中共鉴定出44种香气成分,其中3-羟基-2-丁酮、正丁醛、丁酸等具有果香的挥发性风味物质含量在发酵后均有不同程度的增多。结论:乳酸菌发酵赋予梨汁丰富的营养物质、风味和较高的抗氧化活性,为乳酸菌发酵梨汁提供了一定的理论依据。

大豆酸奶发酵过程中不同蛋白组分理化性质与风味变化研究

大豆酸奶是一种营养健康的新兴植物基酸奶。该研究通过盐析等电点沉淀法从大豆中分离纯化出大豆乳清、7S和11S蛋白组分,探究不同组分在乳酸菌发酵过程中pH值、酸度、乳酸菌增殖、蛋白水解度、粒径的动态变化,以及发酵产物流变特性、微观结构、挥发性化合物以及感官特性的差异,以期阐明不同蛋白组分对于大豆酸奶质地与风味形成的贡献。结果发现,随着发酵时间的延长,大豆11S蛋白发酵物的pH值显著(P<0.05)下降,酸度、乳酸菌增殖数量、水解度和平均粒径显著(P<0.05)增加。同时,流变结果表明11S蛋白发酵物的黏稠程度最高,微观结构表现出粗糙的颗粒状以及更紧密均匀的蛋白聚集状态。此外,GC-MS和电子鼻结果证实7S蛋白经发酵后能产生大量2-己酮、2-辛酮、2-壬酮、2,3-丁二酮、2,3-戊二酮和乙偶姻等酸奶香气化合物,而11S蛋白则产生较多己醛、戊醛、(E)-2-庚烯醛、(E)-2-己烯醛、1-己醇、1-戊醇、1-辛烯-3-醇、苯甲醛、乙酸和2-戊基呋喃等豆腥味化合物,感官接受度较低。结果表明,11S蛋白是酸奶质地形成的关键组分,同时也是与豆腥味化合物相互结合与作用的主要组分。该研究将为大豆酸奶制品的品质优化和风味改善提供理论参考。

发酵馕面团中优势菌群的分离及其在馒头发酵中的应用研究

对新疆地区3份发酵馕面团样品中微生物进行分离、纯化,通过形态观察及分子生物学技术对分离菌株进行鉴定,并通过测定乳酸菌的产酸和酵母菌的产气能力,筛选优良菌株用于发酵馒头的制备,分析其对馒头感官品质及风味物质的影响。结果表明,分离纯化得到36株乳酸菌和51株酵母菌,乳酸菌包括旧金山乳杆菌(Lactobacillus sanfranciscensis)、植物乳杆菌(Lactobacillus plantarum)、发酵乳杆菌(Lactobacillus fermentum)和粪肠球菌(Enterococcus faecalis)4种;酵母菌包括发酵毕赤酵母(Pichia fermentans)、酿酒酵母(Saccharomyces cerevisiae)和膜毕赤酵母(Pichia membranifaciens)3种。植物乳杆菌产酸量最大,为113.55~127.8 g/L;酿酒酵母和发酵毕赤酵母产气较快。发酵毕赤酵母与安琪酵母单独发酵馒头时,在醇类和酯类物质的种类和相对含量上差异较大,风味差异明显;植物乳杆菌与发酵毕赤酵母菌混菌发酵馒头时,随着发酵毕赤酵母添加量增加,可降低馒头中醇类、醛类和烃类物质的相对含量,增加酮类和酯类物质的相对含量,从而形成不同于安琪酵母发酵馒头的风味;当添加比例为1∶2时,馒头感官评分最高(87分)。

Antioxidant,flavor profile and quality of wheat dough bread incorporated with kiwifruit fermented byβ-glucosidase producing lactic acid bacteria strains

This study aimed to investigate the effect of incorporation of kiwifruit substrate fermented by 3 highβ-glucosidase producing lactic acid bacteria(LAB)of Lactobacillus harbinensis(M12,M24)and Pediococcus pentosaceus(J28)on physicochemical and rheo-fermentation properties during proofing of wheat dough.Quality,sensory evaluation,antioxidant content and activity,and flavor profiles of bread was evaluated.Results revealed that LAB strains adequately adapted(J28>M12>M24)and produced enzymes during substrate fermentation.In dough,incorporation of fermented substrate increased acidity,soluble dietary fiber,β-glucosidase andα-amylase activity and gas retention during proofing,in a strain dependent manner(J28>M12>M24).The subsequent breads exhibited higher specific volume and had softer crumbs.Furthermore,total flavonoid,total phenolic,antioxidant activity,flavor content and intensity increased in breads incorporated with fermented substrate.Overall sensory acceptance was in order,bread containing substrates fermented by J28(KFB-J28)>M12(KFB-M12)>M24(KFB-M24)>wheat bread(WB)>bread containing unfermented substrate(KFB).Changes observed were attributed to biotransformation byβ-glucosidase which increasingly degraded dietary fibers into soluble dietary fiber,increased acidity,released glycosylated aroma compounds and phenolic compounds in substrate.When incorporated in dough,fermented kiwifruit substrates stabilized gluten network,increased yeast metabolism and gas retention during proofing.Subsequently,KFB-J28,KFB-M12,and KFB-M24 had higher antioxidant content and activity,higher flavor content and intensity,better quality and were more accepted compared to WB and KFB.This suggested the potential role played byβ-glucosidases through LAB fermentation on functionally enriching and adding value to kiwifruit substrate as a novel functional ingredient in bakery industry.

Development of Tuanfeng Fermented Water Chestnut Beverage

With Tuanfeng water chestnut as a raw material, the optimal fermentation conditions for Tuanfeng fermented water chestnut beverage were obtained as follows ： pulp-to-water ratio at 1：2, inoculation amount of 2.00%, fermentation temperature at 41℃, and fermentation time of 8 h.

酥梨汁乳酸菌发酵工艺优化及挥发性成分分析

以宁陵县金顶谢花酥梨为主要原料,筛选适宜酥梨汁发酵的乳酸菌组合,在单因素实验的基础上,通过正交试验优化乳酸菌酥梨汁的发酵工艺,并对优化后的乳酸菌酥梨汁挥发性成分进行动态分析。结果表明,最优发酵条件为:鼠李糖乳杆菌:嗜酸乳杆菌:乳双歧杆菌=1:1:1(V/V),初始pH4.5,接种量4%,糖添加量10%,发酵时间50 h,此条件下制得的乳酸菌酥梨汁VC含量14.17 mg/100mL、总酸含量7.66 g/L、总酚含量3.68 mg/mL、总黄酮含量6.25 mg/mL,DPPH自由基清除率90.05%,感官评分80.60。通过气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)对乳酸菌酥梨汁在发酵0、30、40、50 h的挥发性成分进行分析,共检测出55种挥发性物质,随着发酵时间的延长,挥发性物质的种类和含量增加,酥梨原汁共有7种挥发性成分,发酵30和40 h的酥梨汁挥发性成分均为27种,发酵50 h的挥发性成分增加至46种,此时,高级醇、高级酯和高级酸类物质大量产生,赋予乳酸菌酥梨汁酸甜口感和独特的风味。

啤特果汁发酵工艺优化

【目的】开发啤特果发酵饮料新产品。【方法】以啤特果汁为原料,通过对不同酵母菌和乳酸菌筛选,在确定了发酵顺序的前提下,采用单因素及响应面设计优化了不同发酵阶段的工艺条件。【结果】安琪耐高糖高活性干酵母菌、干酪乳杆菌更适合作为啤特果汁的发酵菌种;在先酵母菌后乳酸菌发酵,酵母菌接种量1.5%、发酵时间40 h、发酵温度28℃,乳酸菌接种量5%、发酵时间16 h、发酵温度37℃的条件下,啤特果发酵汁总糖可降至(0.986±0.008)g/100 mL。【结论】研究结果为低糖啤特果汁饮品的生产提供了参考。

降解山楂汁中柠檬酸乳酸菌的筛选及工艺优化

初加工的山楂汁中柠檬酸含量丰富,严重影响了山楂汁的口感。试验选用6株乳酸菌,以柠檬酸降解率为指标,筛选降解柠檬酸能力强的乳酸菌,并以其混菌发酵剂发酵山楂汁,采用响应面法对其工艺进行优化。试验结果表明,短乳杆菌、干酪乳杆菌和柠檬明串珠3株菌株具有较好降酸能力,以3株菌株1∶1∶1比例制成混菌发酵剂发酵山楂汁,最佳发酵降酸工艺为发酵温度34.3℃、接种量3%、发酵天数1.8 d。经发酵后,山楂汁的柠檬酸、苹果酸含量下降,营养成分提高,色泽状态良好。

乳酸菌对发酵肉制品抑菌作用及风味特征的影响研究进展

发酵肉制品因生产周期较长、营养物质丰富,极易受到微生物的污染,从而影响产品品质并对人体健康带来不利的影响。由于消费者对发酵肉制品风味以及安全性的关注日益增加,因此对肉制品的安全性以及风味特征的研究非常重要。乳酸菌是最早从发酵肉制品中分离出来的微生物,是传统发酵肉制品中重要的优势菌群,与产品品质密切相关。在发酵肉制品中,乳酸菌不仅可以产生具有抑菌作用的物质抑制有害微生物生长,提高肉制品的安全性;还可以通过影响碳水化合物代谢、蛋白质以及脂质的分解氧化,从而改善发酵肉制品的风味。本文主要从乳酸菌影响发酵肉制品中有害微生物的生长、提高产品安全性及其对风味形成的影响方面进行综述,以期为今后发酵肉制品的研究提供新思路。

大豆酸奶风味物质研究进展

近年来,随着行业和消费者对健康和环保的认识不断提高,植物基酸奶产品市场得到快速发展。大豆是最主要的植物基蛋白来源之一,营养丰富且具有多种生理活性物质,以大豆蛋白等植物基蛋白发酵的植物酸奶具有绿色健康等优点,但产品容易出现豆腥味或者苦涩味等不良风味问题,风味不佳是目前大豆酸奶产品发展的主要技术瓶颈。本文介绍了大豆酸奶主要风味来源、风味物质分类及风味改良方法,其中大豆酸奶的不良风味主要来源于大豆原料自身风味物质及发酵过程中乳酸菌产生的挥发性风味物质,本文提出了改善大豆酸奶产品风味的关键在于优化发酵原料、改善原料加工工艺及筛选适合大豆蛋白发酵的风味菌株,为今后的大豆酸奶研究和产业发展提供思路。