老酵面团对碱工艺最佳pH值的研究

用老酵来发酵的面团其制品口感好，风味好。由于发酵过程产生有机酸对碱中和，如何控制对碱量，达到最佳风味效果，历来为面点工艺上的一个难点。研究证明，发酵面团对碱后立即制作，其面团的ｐＨ值在６．１５～６．２０区域内，制成品的效果很好，发酵面团对碱再醒发２５分钟后，其面团的ｐＨ值在６．１２～６．１５区域内，这时制成品的效果更好。     

风味发酵液发酵面团挥发性风味物质及特征分析

目的:探究不同发酵时间下风味发酵液发酵面团的挥发性成分种类及含量。方法:采用顶空固相微萃取—气质联用法(HS-SPME-GC-MS)测定风味发酵液发酵12,24,36,48,72 h时,面团中的挥发性风味物质,并进行气味感官评定及pH值、总酸度(TAA)和面团流变学特性测定。结果:因不同发酵时间下产生的风味物质的种类和含量不等,8种气味(乳香、干酪味、花香味、水果甜香、酒味、麦芽味、青草香和酸味)的强弱度不同;面团pH值随发酵时间的延长逐渐降低,TTA则相反;面团的拉伸阻力、拉伸比及拉伸面积随发酵时间的延长整体呈先增后减趋势,延伸性则先下降后升高,表明适度发酵(发酵36 h)有利于面筋网络的形成和稳定。5个面团中共检出92种挥发性物质,其中醇类22种、酯类27种、醛类12种、酮类14种、烷烃类10种、酸类7种;发酵12,24,36,48,72 h的面团中分别检出27,43,38,41,37种挥发性风味成分,其中酸类及酯类物质含量随发酵时间的延长先升后降,均在48 h达到最高(分别为47.31%和20.96%),醛类、酮类及酸类物质含量则随发酵时间的延长逐渐降低。结论:不同发酵时间的挥发...     

鱼骨粉添加对馒头发酵能力的影响

该文以鱼骨粉为试材,以馒头发酵能力为指标,探究鱼骨粉添加量对馒头发酵能力的影响,优化鱼骨粉馒头制作的工艺条件。通过测定面团发酵过程中pH值、酸度等的变化研究鱼骨粉添加量对面团发酵能力的影响。结果表明,在面团发酵期间pH值均呈下降趋势,鱼骨粉添加量为6%的面团产气速度相对过快,导致发酵结束后面团并没有充分膨胀,面筋并没有充分延伸。骨粉添加量低于6%的面团产气速度较为均匀,能使面团最大限度膨胀,更适用于生产馒头。     

乳酸菌协同发酵对饼干风味的影响及应用

本文基于消费者喜好酸度的探究,考察乳酸菌协同发酵对饼干风味特性的影响。经消费者对不同pH值面团制备的乳酸菌协同发酵饼干的喜好度评价显示,当发酵面团p H值为4.35~4.20时具有较高的消费者喜好度评分。采用21株乳酸菌发酵制备饼干,观察其对产品风味的影响。经感官描述性分析发现,坚果味、水果味(气味和滋味)、乳品酸味和甜味的强度与消费者喜好度呈正相关;而丁酸味、苦味和酵母味风味强度则与喜好度呈负相关。不同乳酸菌制备的发酵饼干中风味物质的种类和含量均具有差异。酯类、羰基类及烃类化合物的含量与消费者喜好度呈正相关;而有机酸及醚类物质种类及含量的不同是决定产品风味差异及喜好度评分不同的主要因素之一。结果表明,乳酸乳球菌XX3发酵制得的饼干具有较好的感官风味品质,其果香风味强度及酯类物质含量显著高于其他组饼干。     

乳酸菌对酵母菌发酵多谷物杂粮面包品质的影响

目的:探讨添加乳酸菌粉对酵母菌发酵多谷物杂粮面包品质的影响。方法:检测添加不同比例（0、0.03%、0.06%、0.09%、0.12%）乳酸菌粉发酵多谷物杂粮面团的pH、发酵体积和流变特性指标变化,同时检测添加乳酸菌粉后杂粮面包硬度、胶黏性、咀嚼性指标,以及面包比容、感官品质和风味指标的变化。结果:添加乳酸菌发酵使多谷物杂粮面团pH降低;添加0.03%~0.12%混合乳酸菌粉发酵60 min面团体积增加50.00%~88.12%,均高于单一酵母菌发酵（增加48.51%）;添加乳酸菌粉降低了面团储能模量（G'）和损耗模量（G"）值,添加量0.06%时G'和G"值分别降低33.33%和30.00%,降低幅度最小;添加0.06%乳酸菌粉,可显著降低面包硬度、胶粘性和咀嚼性（P<0.05）,显著提高面包弹性（P<0.05）,改善面包质构特性,面包比容比单一酵母菌发酵增加24.88%,面包形态、质地、纹理结构、风味和口感均具有较好的改善,感官品质显著提高（P<0.05）,感官评分超过80分。酵母菌联合乳酸菌发酵复配杂粮面包,共检测出65种挥发性风味物质,化合物种类多于小麦面包43种,风味物质强度高于单一酵母菌发酵杂粮面包。结论:添加乳酸菌粉对酵母菌发酵多谷物复配杂粮面包品质改善具有积极作用。     

不同乳酸菌发酵豆乳对面团发酵特性及馒头品质的影响

以大豆为原料，选用从扬州市富春茶社老酵面团中筛选获得的3株乳酸菌为发酵菌，探究了3种单一乳酸菌和复合乳酸菌（1∶1∶1）发酵豆乳对面团发酵特性和馒头品质的影响。结果表明，与单一菌株发酵相比，复配发酵豆乳的酸度和活菌数更高，分别为85.06°T和9.66(lg(CFU/mL)),3株乳酸菌在豆乳中具有良好的共生关系。同时，与对照组相比，添加发酵豆乳显著提高了面团发酵后的有机酸含量和活菌数，其中戊糖乳杆菌203发酵豆乳面团的乳酸含量和活菌数最高，分别为18.57 mg/g和8.94(lg(CFU/g))；而发酵乳杆菌202发酵豆乳面团乙酸含量最高，为3.81 mg/g。与对照组馒头相比，添加发酵豆乳4组馒头的比容、弹性和高径比均显著提高，而硬度和咀嚼性均显著降低，复配组馒头获得了最高的整体可接受度。风味结果显示，在5组馒头中共检测出48种挥发性风味物质，其中复配组馒头的风味物质相对含量和种类最多，分别为71.62%和47种。在4℃储藏4 d后，4组发酵豆乳馒头的水分损失率和回生焓值均显著低于对照组，其中复配组的水分含量最高，为38.53%；回生焓值最小，为1.00 J/g。综上可知，添加发...     

副干酪乳杆菌对小麦发酵面团流变特性与风味的影响

本研究针对小麦乳酸菌发酵型面团产品市场空缺及副干酪乳杆菌在食品工业中的应用,以高筋小麦粉、副干酪乳杆菌N1115与N3117为原料,采用Mixolab混合仪试验、旋转流变仪频率扫描试验、气相色谱-质谱联用(GC-MS)试验,测定小麦面团的黏度、流变学特性以及风味物质的组成及含量。结果表明,小麦面粉与N1115,N3117混合酵母发酵后形成的面团黏度处于正常范围,粉质曲线趋于稳定,面筋强度增加,加工特性优异;添加了N1115及N3117的小麦面团发酵后储能模量G'和损耗模量G'降低,面筋蛋白弱化度增加,面团的流变学特性略有下降;通过气-质谱联用试验在N1115与酵母菌混合添加的小麦发酵面团中检测出28种风味物质,N3117与酵母菌混合添加的小麦发酵面团中检测出63种风味物质,并且面团中酯含量大大提高,面团的香味更加浓郁。     

高产胞外多糖旧金山乳杆菌的筛选及其在馒头中的应用

为改善当前活性干酵母发酵面制品感官及风味的不足,本研究以分离自传统发酵酸面团中的旧金山乳杆菌为研究对象,筛选高产胞外多糖旧金山乳杆菌菌株,将其应用于馒头的制作。研究结果表明:在51株旧金山乳杆菌中,旧金山乳杆菌Ls-1001的胞外多糖产量高达190.32 mg/L。通过对面团发酵过程中各项指标的测定,在馒头的制作过程中,添加旧金山乳杆菌能降低馒头水分,增加比容,降低酸面团pH值,增加总酸度,对活性干酵母馒头的感官品质有明显改善。本研究有望促进传统发酵面制品工业化发展,为广大消费者提供更高品质和营养价值的传统发酵面食。     

馒头发酵过程中酵母菌和乳酸菌的代谢作用

和制馒头面团时,添加20% 由酵母菌(Saccharomyces cerevisiae CGMCC 2.0562)和/ 或乳酸菌(Lactobacillus brevis CGMCC 1.0579)发酵的老面团进行混合发酵,通过检测pH 值、总酸度及可溶性糖含量的变化,研究老面团馒头发酵过程中微生物生长及代谢特性。采用高效液相色谱 (HPLC)- 蒸发光散射检测器(ELSD)检测可溶性糖(麦芽糖、蔗糖、果糖、葡萄糖)含量,其流动相为乙腈- 水体积比70:30,流速1.0mL/min,柱温25℃,ELSD 漂移管温度83.5℃,载气空气流速2.2L/min。结果显示：与对照组相比,添加老面团的样品pH 值较低,TTA 值较高,尤其是添加单一乳酸菌发酵老面团的样品酸度最低;不同样品发酵过程中各种可溶性糖的含量及变化趋势存在差异。由此看出,不同菌种对原料的利用不同,所以馒头面团发酵过程中代谢产酸及可溶性糖含量变化存在差异,这很可能会影响到馒头的品质。     

全麦发酵面团菌群结构分析及对风味物质的影响

采用宏基因组学的方法解析全麦传统发酵面团细菌菌群结构组成,确定其核心菌属为乳酸菌科乳杆菌属短乳杆菌种。对全麦传统发酵面团和商业发酵面团的风味物质进行了测定,发现传统发酵面团风味物质种类比商业发酵多9种,在含量上也存在差异,但均以烃的含量最多。说明传统发酵剂更有利于全麦面团风味物质的形成,更易让消费者接受,为传统发酵剂在全麦制品中的应用提供理论支持。     

Survival and growth of acid-adapted and unadapted Shigella flexneri in a traditional fermented Ghanaian weaning food as affected by fortification with cowpea

Shigellae are among the major causes of diarrheal diseases in infants and young children in developing countries. We conducted a study to determine the effect of fermentation of corn and corn/cowpea doughs used to prepare a traditional weaning porridge on the survival and growth characteristics of acid-adapted and unadapted Shigella flexneri. Porridges were prepared from doughs fermented for 0, 24, and 48 h at 30 degrees C. Four-strain mixtures of acid-adapted and unadapted S. flexneri cells were separately inoculated (10(4)-10(5) and 10(6)-10(7) cfu/ml) into porridges made from unfermented (pH 5.74-6.05) and fermented (pH 4.07-4.38) doughs. Viability of acid-adapted cells was retained at higher levels in porridge made from fermented dough, compared to unfermented dough, regardless of composition of the porridge or incubation temperature. Cells inoculated into the porridges containing fermented dough were not detected (<1 cfu/ml) within 4 h at 48 degrees C. Results indicate that prior exposure of cells to acid stress renders them more resistant to subsequent acidic conditions. The addition of cowpea flour to corn dough followed by fermentation had little effect on the survival of S. flexneri in porridges made from the dough.     

自然发酵面团中分离的发酵乳杆菌对高脂饮食小鼠的降血脂作用

该研究从哈尔滨周边地区农户家的自然发酵面团中分离纯化乳酸菌,分别评价分离菌株的耐酸耐胆盐及抑菌特性,并利用溶血性试验和抗生素敏感试验评估其安全性。以邻苯二甲醛法对乳酸菌菌株的降胆固醇能力进行体外分析,并利用高脂模型小鼠研究其体内降胆固醇功能。结果共分离得到16株乳酸菌,其中发酵乳杆菌FD-8在酸性和胆盐条件下存活率可达80.21%和75.98%,对致病性大肠杆菌、金黄色葡萄球菌和鼠伤寒沙门氏菌均有一定的抑菌作用且安全性良好。FD-8菌株的体外降解胆固醇率达到85.66%,体内饲喂FD-8菌株5 w后能明显降低高脂饮食小鼠的体质量和肝脏指数,改善高脂饮食诱导的小鼠血清及肝脏中总胆固醇、低密度脂蛋白胆固醇和甘油三酯水平的改变,达到降血脂的目的。该研究从自然发酵面团中分离到的发酵乳杆菌FD-8具备良好的耐酸、耐胆盐和抑菌特性,能够在体内外发挥降胆固醇作用,同时无溶血性且对某些抗生素表现一定的敏感性,对于进一步开发降胆固醇产品具有重要意义。     

小米发糕发酵剂中乳酸菌的筛选及其在小米发糕中的应用

以5种小米品种为研究对象,通过自然发酵法制备小米发糕发酵剂,测定菌落总数、感官评定发糕品质,获得品质差异较大的2种发酵剂,并对其中的乳酸菌进行分离、纯化,通过形态学、生理生化和测序进行鉴定。且研究了乳酸菌对小米发糕含水量、pH、TTA值、糖度和感官品质的影响。结果表明,乳酸菌的计数结果分别为6.48×10~7～8.57×10~9 cfu/g,1号(长农35)制备的小米发糕品质最好,6号(长谷4号)反之。2种发酵剂中鉴定出乳酸菌包括食窦魏斯氏菌(11株)、魏斯氏菌属(18株)和柠檬明串珠菌(4株),其中优势菌为魏斯氏菌属。乳酸菌LA6-40发酵制备的小米发糕含水量39.74%、pH 6.20、TTA值5.3、还原糖含量2.27 g/100 g,感官评分77.1分,色泽金黄、口感细腻、酸甜适中、咬劲适度、弹性良好,是较为适合小米发糕制备的乳酸菌菌株。     

Interactions between yeasts and bacteria in the smear surface-ripened cheeses

Sufu or furu is a fermented soybean product originating in China. It is a cheese-like product with a spreadable creamy consistency and a pronounced flavour. Sufu is a popular side dish consumed mainly with breakfast rice or steamed bread. It has a long history and written records date back to the Wei Dynasty (220-265 AD). Sufu is made by fungal solid state fermentation of tofu (soybean curd) followed by aging in brine containing salt and alcohol. The present review is based on scientific data published in Chinese and international sources. Several types of sufu can be distinguished, according to processing method or according to colour and flavour. Choice of processing can result in mould fermented sufu, naturally fermented sufu, bacterial fermented sufu, or enzymatically ripened sufu. Depending on the choice of dressing mixture, red, white or grey sufu may be obtained. The stages of the process are discussed and include the preparation of tofu, the preparation of pehtze, salting and ripening. Fungal starters include Actinomucor spp., Mucor spp. and Rhizopus spp. The chemical composition is discussed with particular reference to the proximate composition, the amino acid content and profile, as well as the volatile flavour components of various types of sufu.     

Maillard volatiles in baked products as affected by feruloylated oligosaccharides from maize bran

Feruloylated oligosaccharides (FOs) have been approved by the US Food and Drug Administration to be incorporated in baked goods. This research aimed to investigate the influence of FOs on flavour formation. Results revealed that the furfural content increased 5.2-, 6.7-, 5.6-, and 6.5-fold after 10 mg/g FOs was added and by 6.7-, 37.8-, 12.4-, and 64.5-fold after 50 mg/g FOs was added to aspartic acid/glucose, asparagine/glucose, glutamic acid/glucose, and dough models, respectively. Addition of FOs prevented the formation of favourable Maillard flavour compounds, such as pyrazines, maltol, nonanal, and cedrol, but produced unpleasant flavour compounds, such as dimethyl disulphide, dimethyl trisulphide, and 2-methoxy-4-vinylphenol. Our findings suggest that the addition of FOs to thermally processed food should be evaluated with caution.     

The effects of the organic acids in cocoa on the flavour of chocolate

Samples (54) of dried fermented cocoa beans from different world regions were analysed for levels of organic acids, pH and titratable acidity. The effects of the organic acids on the flavour characteristics of cocoa were examined by sensory evaluation of chocolate made from samples of cocoa beans. Concentrations (g kg^?1) of acids ranged from 1.3 to 11.8 for acetic, 1-6 to 9-9 for citric, 0.6 to 11.1 for lactic and 2.1 to 6.5 for oxalic. pH values ranged from 4.6 to 5.8, while titratable acidity ranged from 0.08 to 0.31 equivalents of sodium hydroxide per kg sample. Cocoas from South East Asia and the South Pacific tended to be more acidic than West African beans in terms of both chemical and sensory characteristics. Lactic and acetic acids were found to be in greater concentrations in cocoas from the former regions and were considered to be largely responsible for higher acid flavour scores. In contrast, citric and oxalic acids were generally lower in these beans. Flavour assessments of cocoas with and without added organic acids indicated that oxalic acid played an important role in chocolate flavour. These results suggest that a reduction in the levels of acetic and lactic acids only, may not be sufficient to produce a desirable flavour balance.     

产香酵母发酵面团挥发性风味物质分析

采用分离自山东酵子具有优良发酵和产香特性的酿酒酵母（Saccharomyces cerevisiae）CGMCC No.24005,制成干粉发酵剂,并分析其生长发酵特性及发酵面团的香气成分。结果表明,该酵母的最适生长温度、pH分别为28℃、6;发酵16 h时面团体积最大。利用此酵母发酵面团整体香气较强,酯类与醇类的种类及含量显著高于未发酵组（P<0.05）,果香、花香、酒香、甜香等特征明显,其中乙酸异戊酯、异戊醇、辛酸乙酯、苯乙醇等是不同发酵时间产物呈现不同香气特征的关键物质。说明该发酵剂能显著增加面团挥发性物质种类及含量,可提升发酵面食的品质,为传统发酵面食的标准化生产提供理论参考。     

碱添加量对米酒酸面团及馒头品质的影响

该实验研究了碱添加量对面团的pH、湿面筋含量、面筋指数及馒头的比容、硬度、白度、感官评分的影响。结果表明,碱添加量与pH值呈线性关系。碱添加量为0.20%时,显著降低了面团中湿面筋含量,但提高了面筋指数。碱添加量＞0.20%之后,馒头的感官评分、白度、比容呈现降低趋势,硬度呈现上升趋势。相关性分析结果表明,面团pH值与馒头的比容、白度呈极显著负相关（P＜0.01）;与馒头的感官评分呈极显著正相关（P＜0.01）。面团湿面筋含量与馒头比容呈显著负相关（P＜0.05）,与馒头硬度呈极显著正相关（P＜0.01）。面团面筋指数与面团比容呈显著正相关（P＜0.05）,与馒头硬度呈极显著负相关（P＜0.01）。     

A Traditional Turkish Fermented Cereal Food: Tarhana

Tarhana has a long history. According to historical records, it was first produced by Turkish people in Middle Asia and afterwards it spread out to different parts of the world. It is a fermented cereal-based food and can be simply defined as a mixture of yoghurt, cereal flours, yeast, different vegetables, herbs, and spices. After the mixing process, tarhana dough is fermented for 1 to 5 days and immediately dried. Both lactic acid bacteria (LAB) and yeast fermentations occur simultaneously during tarhana production. Therefore, tarhana has sour and acidic taste with yeast flavour as well. It is sun-dried at the home-made level or oven-dried of the commercial level. Several types of tarhana can be classified depending upon processing method or raw materials used. Low moisture (6–10%), low pH (3.5–5.0), and components (organic acids, bacteriosin, etc.) formed in fermentation have bacteriostatic effect on pathogens and spoilage microorganisms during long term storage (1–2 years) and enhance shelf life. Since tarhana is a good source of B vitamins, minerals, organic acids, and free amino acids, and since it is a product of LAB and yeast fermentation, it may be considered a functional and probiotic food.     

食品添加剂对冷藏发酵糙米面包品质的影响研究

通过使用食品添加剂(羧甲基纤维素钠、瓜尔胶和单双甘油脂肪酸酯)改良冷藏发酵糙米面包品质,以面团的质构特性、水分状态、发酵力及其面包的质构特性、色泽和比容为评价指标,通过对比研究确定冷藏发酵糙米面包中添加剂的最适添加量。结果表明:0.04%羧甲基纤维素钠、0.04%瓜尔胶和0.04%单双甘油脂肪酸酯按1∶1∶1组成的0.12%复配添加量为冷藏发酵糙米面包最适添加量,与未使用添加剂的对照组相比,面团和面包硬度降低了30.8%和45.7%,弹性提高了54.7%和23.3%;面团强结合水和弱结合水显著增多,内部水分稳定,且面团发酵力增大了42.8%;相应面团制作的面包颜色最浅最亮白,面包比容增大了53.6%。