慈姑粉的喷雾干燥工艺优化

以慈姑酶解液为原料,研究助干剂对慈姑出粉率的影响,在最优助干剂添加量的基础上,以出粉率、含水量及感官评分为评价指标,优化喷雾干燥过程中进风温度、进料流量和热空气流量参数,确定最佳干燥工艺条件。结果表明:在麦芽糊精添加量为40%,进风温度为180 ℃,进料流量为25%,热空气流量为36 m3/h时,慈姑出粉率最高,达48.51%±0.63%,比不添加助干剂的出粉率高出31.32%,含水量为4.86%±0.07%,慈姑粉为乳白色,粉粒细小均匀,风味浓厚,冲调性好,感官性状最佳。采用助干剂协同喷雾干燥技术制备慈姑粉能显著提高出粉率,改善慈姑粉品质。     

大豆益生元发酵豆乳的制备及其对益生菌数量的影响

该文采用干酪乳杆菌与鼠李糖乳杆菌混种发酵大豆低聚糖,优化大豆益生元发酵豆乳制备工艺。通过单因素及正交试验,得到最佳工艺为:干酪乳杆菌与鼠李糖乳杆菌比例1∶1、果胶的添加量0.3%、豆粉与水质量体积比1∶12(g/mL)、脱脂乳粉添加量24%、大豆低聚糖添加量25%、接种量5%、发酵温度37℃、发酵时间7 h、后熟时间18 h^24 h。食用150 mL/d此条件下制备的大豆益生元发酵豆乳不仅感官品质最佳,并且对益生菌的生长具有显著的增殖作用。     

一株产细菌素植物乳杆菌高密度发酵培养基的筛选及其在酸奶中的应用

目的:优化用于高密度发酵产细菌素的植物乳杆菌KLDS 1.0391的经济有效培养基,旨在生产具有益生作用的辅助发酵剂。方法:以发酵液中活菌数量和抑菌效果为指标,比较不同水解度的脱脂乳粉、乳清粉、麦麸,以及玉米浆粉的发酵效果,制备冻干形式的植物乳杆菌直投式发酵剂,将其添加至酸奶中,评价其对酸奶发酵时间、pH、滴定酸度、粘度和感官评价的影响,进而确定其在酸奶中应用的可行性。结果:确定脱脂乳粉、乳清粉和麦麸培养基的最佳水解度分别为15%、15%和20%;植物乳杆菌KLDS 1.0391在玉米浆粉培养基中获得的发酵效果最佳,活菌数量达到9.53 lg CFU/mL,抑菌圈直径达到12.69 mm。植物乳杆菌直投式菌种的添加对酸奶发酵时间和感官评价无显著影响(P>0.05),酸奶粘度下降,但可以缓解酸奶的后酸化程度。通过优化得到植物乳杆菌KLDS 1.0391高密度发酵的廉价培养基为:4%玉米浆粉,同时补充2%葡萄糖和0.1% Tween-80。结论:制得的植物乳杆菌直投式发酵剂可应用于酸奶生产中。     

益生菌发酵葡萄汁饮料工艺研究

以巨峰葡萄为原料,进行益生菌发酵葡萄汁工艺研究。以嗜酸乳杆菌（Lactobacillus acidophilus）L2-16为发酵菌种,活细胞数和感官品质为评价指标,通过单因素试验及正交试验优化发酵工艺条件。结果表明,初始pH值、接种量、发酵温度和发酵时间对嗜酸乳杆菌活菌数和感官品质影响显著,益生菌发酵葡萄汁的最佳工艺条件为初始pH值4.5,接种量2.5%,发酵温度32 ℃,发酵时间26 h。在此优化条件下,发酵葡萄汁饮料活菌数对数值为8.87,感官评分为88.3分,酸度为90.1 °T,可溶性固形物含量17.2%。     

喷雾干燥制备海参肠卵肽粉的工艺条件优化

以海参肠卵为基本原料,经过酶解、发酵,添加麦芽糊精为助干剂,采用喷雾干燥法制备海参肠卵肽粉,在单因素试验的基础上,以集粉率、含水量为响应值,采用Box-Behnken中心组合方法对喷雾干燥参数条件进行响应面试验设计,研究麦芽糊精添加量、进风温度、蠕动泵转速对海参肠卵肽粉品质的影响。结果表明：海参肠卵肽粉制备的最佳工艺参数为麦芽糊精添加量20%,进风温度155℃,蠕动泵转速10 r/min。在此条件下制备的海参肠卵肽粉集粉率达68.69%,含水量达1.52%,与响应面模型预测值符合。制备的海参肠卵肽粉色泽呈淡黄色,组织细腻均匀,无腥味异味,溶解性好。     

响应面法优化嗜酸乳杆菌和植物乳杆菌制备燕麦芽益生菌饮料的条件

以裸燕麦和燕麦芽为原料,嗜酸乳杆菌和植物乳杆菌为菌种,对发酵基质配方进行优化,以得到一种富含益生菌和β-葡聚糖的益生菌产品。通过单因素试验考察燕麦芽-燕麦粉浓度、燕麦芽粉与燕麦粉比例、脱脂乳粉浓度、蔗糖浓度对饮料中活菌数、滴定酸度、β-葡聚糖含量和游离氨基酸含量的影响。在此基础上,采用响应面法以活菌数和β-葡聚糖含量为指标优化燕麦芽益生菌饮料。结果表明,蔗糖含量对饮料各指标没有显著影响,当燕麦芽-燕麦粉含量10%,燕麦芽粉与燕麦粉比例2∶1,脱脂脱脂乳粉质量分数1%时,燕麦芽益生菌饮料的活菌数为8.75 lg(CFU/m L),β-葡聚糖含量564.81 mg/L,与模型预测值较为吻合。     

西红柿益生菌酸乳的研制

利用鲜牛乳和番茄汁为原料,通过添加嗜酸乳杆菌发酵来制备西红柿益生菌酸乳;通过测定活菌数和感官评定确定了番茄汁最适的添加量,测定了嗜酸乳杆菌的发酵特性,发酵结束后在4℃下贮存,在此过程中测定了嗜酸乳杆菌的存活状态及贮存过程中酸度和pH的变化,分析了番茄汁对嗜酸乳杆菌发酵的影响.实验结果表明,蔗糖添加量为8%,嗜酸乳杆菌发酵剂的接种量为45,发酵温度为37℃,发酵时间为9h,可以得到呈浅红色,状态均匀,酸甜适口的西红柿益生菌酸乳,40C下贮存10d后嗜酸乳杆菌活菌数仍达107cfu/mL以上.     

响应面法优化黑米红枣活性乳酸菌发酵工艺

以黑米和红枣为主要原料,预处理后添加蔗糖、脱脂乳粉,通过乳酸菌发酵制成含有活菌的发酵饮品。在单因素试验的基础上,通过4因素3水平的响应面分析法,发酵饮料的配方进行优化。结果表明:响应面法优化的黑米红枣发酵饮料最佳配方为黑米汁红枣汁体积比3∶2、蔗糖添加量5%、乳酸菌接种量(保加利亚乳杆菌∶嗜热链球菌体积比3∶2)3%、脱脂乳粉添加量3%。该条件下制得的产品感官评价得分为89.60分,色泽、口感和质地均较理想。     

枸杞南瓜粉的制备、体外消化特性和抗氧化活性的研究

以枸杞、南瓜为原料,利用植物乳杆菌（Lactobacillu plantarum）和鼠李糖乳杆菌（Lactobacillus rhamnosus）混菌（5∶1）发酵枸杞南瓜汁,以喷雾干燥法制备枸杞南瓜粉,采用单因素试验及正交试验优化喷雾干燥工艺,并通过体外模拟胃肠消化试验及自由基清除试验研究枸杞南瓜粉的消化特性及氧化活性。结果表明,最佳喷雾干燥工艺为进口热风温度160 ℃,进料流量7.5 mL/min,脱脂乳粉添加量2.5%。在此优化条件下,枸杞南瓜粉呈淡红色,集粉率40.3%、感官评分89.3分。体外消化特性及抗氧化活性试验结果表明,消化结束后测得发酵组消化液中总多酚、总黄酮含量分别上升了2.21%、6.35%,2,2-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐（ABTS+）自由基、1,1-二苯基-2-三硝基苯肼（DPPH）自由基、羟基自由基清除率分别为58.26%、86.43%、70.98%,显著高于对照组（P＜0.05）,且肠消化阶段的抗氧化能力显著高于胃消化阶段（P＜0.05）。     

山楂饮料发酵工艺

以山楂为原料,利用植物乳杆菌PMO发酵,研制具有山楂特殊风味和营养价值的山楂乳酸发酵饮料。以pH、总酸、总黄酮含量、乳酸菌活菌数、感官评分为指标,研究了接种量、发酵时间、发酵温度、糖添加量对发酵的影响。并在单因素试验的基础上,以发酵饮料乳酸菌活菌数和感官评分为评价指标,采用正交试验优化山楂活菌饮料的发酵工艺。结果表明,山楂活菌饮料适宜的发酵条件为:蔗糖与葡萄糖的质量比为3:2、植物乳杆菌接种量4%、发酵温度37℃、发酵时间18 h、糖添加量的质量分数为8%。在此条件下,测得的山楂发酵液的活菌数为8.334 lg(CFU/mL),感官评分91.5。     

发酵核桃粕复合粉中乳酸菌保护剂的筛选

采用Plackett-Burman设计筛选试验,从谷氨酸钠、脱脂乳粉、海藻糖、麦芽糊精、蔗糖、阿拉伯胶、甘油7个因素中对发酵核桃粕复合粉乳酸菌的保护剂进行筛选,再采用最陡爬坡试验确定响应面的中心点,最后采用Box-Behnken试验对其进行优化。结果表明,经Plackett-Burman设计筛选后,对乳酸菌活菌率影响较突出的为海藻糖、脱脂乳粉、麦芽糊精;经响应面优化后最佳保护剂配比为海藻糖2.23%、脱脂乳粉2.50%、麦芽糊精2.77%,再经真空干燥制粉,活菌总数为9.71×108 CFU/mL,能最大限度保留乳酸菌的活菌数。     

Effects of inulin and sugar levels on the viability of yogurt and probiotic bacteria and the physical and sensory characteristics in probiotic ice-cream

Ice-cream containing probiotic bacteria was produced by mixing fortified milk fermented with probiotic strains with ice-cream mixes with different sugar concentrations (15, 18, 21% (w/w)). Cultures were grown (37 °C, 12 h) in UHT skimmed milk supplemented with or without inulin addition (1% and 2%). The fermented milk was added to the ice-cream mix to a level of 10% w/w.     

Fish oil microencapsulation as influenced by spray dryer operational variables

The effects of spray‐drying air temperature, aspirator rate (drying air mass flow rate), peristaltic pump rate (feed mass flow rate) and spraying air mass flow rate on microencapsulation properties of fish oil including moisture content, particle size, bulk density, encapsulation efficiency and peroxide were investigated. The process was carried out on a mini spray dryer, and skim milk powder was used as the encapsulating wall material. Results indicated that increasing inlet air temperature increased the particle size, encapsulation efficiency and peroxide value but decreased the bulk density and moisture content of product. Increasing aspirator rate resulted in increased particle size and peroxide value but decreased the moisture content and bulk density. Increase in feed mass flow rate increased the moisture content, particle size, bulk density and peroxide value but decreased the encapsulation efficiency of microcapsules. The encapsulation efficiency and bulk density increased with the increasing aspirator rate but moisture content, particle size and peroxide value decreased.     

一种百岁老人源罗伊氏乳杆菌益生特性及其发酵水牛乳制备工艺优化

为探索新筛选的一株百岁老人源罗伊氏乳杆菌LT018开发利用价值,本研究首先检测了该菌株在连续培养300代过程中的活菌数、菌活力,判断其遗传稳定性,又对该菌株在模拟胃肠液中存活率及凝集率进行测定,判断该菌株的益生特性。进一步以此菌株与传统保加利亚乳杆菌和嗜热链球菌发酵剂相结合制备发酵水牛乳,在单因素实验的基础上,通过响应面实验探索其最佳工艺。结果显示,在连续培养300代的过程中,罗伊氏乳杆菌LT018的活菌数和菌活力均保持在一个较高的水平;菌株在模拟胃液和肠液中的存活率分别高于99.07%和77.83%;同时保持大于55.4%的凝集率。发酵水牛乳最佳制备工艺为:罗伊氏乳杆菌发酵剂:传统发酵剂为2:1、白砂糖添加量为3.00%、发酵温度为40.00℃,此时发酵乳的感官评分最高(86.63±1.47),罗伊氏乳杆菌活菌数也达到了1.033×108 CFU/mL。本研究为该菌株的开发利用提供了重要的理论和技术参考。     

响应面法优化欧李果汁与牛奶复合益生菌饮料发酵工艺

以欧李（Cerasus humilis）果汁与牛奶为主要原料制作复合益生菌饮料,以总抗氧化能力和活菌数为评价指标,经单因素试验分析发酵菌株、果浆浓度、脱脂牛奶添加量、糖度、接种量和发酵时间对发酵饮料的影响,并通过响应面试验对影响较大的4个因素进行优化,确定复合益生菌饮料最佳工艺。结果表明,最佳发酵工艺为发酵菌株植物乳杆菌（Lactobacillus plantarum）和嗜酸乳杆菌（Lactobacillus acidophilus）（1∶1）,欧李果汁添加量49%,脱脂牛奶添加量12.3%,糖度12 °Bx,接种量6%,发酵时间41 h。在此优化发酵工艺条件下,饮料总抗氧化能力为143.33 U/mL,活菌数为8.70 lg（CFU/mL）,色泽鲜艳呈粉红色,气味纯正,具有欧李果香,酸甜可口,滋味宜人。     

复合菌发酵米乳饮料的配方优化及其储藏品质变化

以米粉和脱脂乳为主要原料,基于发酵米乳复配菌株适宜配比的优化,研究米乳饮料的配方及其储藏品质。比较商用酸奶发酵剂(保加利亚乳杆菌和嗜热链球菌)和植物乳杆菌ZSM-002在米乳中的发酵特性,确定发酵米乳复配菌株适宜配比;通过单因素和正交试验优化米乳饮料配方(米水比、脱脂乳加量、白砂糖加量、菌接种量、发酵时间和发酵温度);采用均匀设计试验,通过考察离心沉淀率确定复配稳定剂配比;最终研究优化米乳饮料的储藏品质。结果表明,商用酸奶发酵剂和植物乳杆菌ZSM-002以3:2复配效果较好;优化的米乳饮料配方为:米水比1:10 (g/mL)、复合菌3%、脱脂乳10%、白砂糖9%、复合稳定剂0.2%(海藻酸丙二醇酯60%,蔗糖脂肪酸酯0.2%,果胶38%,黄原胶1.8%),37 ℃发酵10 h,此条件下发酵米乳饮料的离心沉淀率为2.25%,滴定酸度为(17.03±0.92) °T,活菌数为(8.53±0.08)lg (cfu/mL),感官评分为(8.83±0.20)分;在4 ℃条件下储藏7 d后,其酸度为(34.2±1.56) °T,活菌数为(7.44±0.12)lg (cfu/mL),满足乳酸菌饮料益生菌存活数达到106 cfu/mL标准,制作的米乳饮料口感黏稠,有柔和的乳酸风味。     

乳酸菌在绿豆酸奶粉中的应用研究

以绿豆浆和牛乳作混合原料,经保加利亚乳杆菌和嗜热链球菌发酵制备成绿豆酸奶后,配以奶粉、麦芽糊精及保护剂等进行喷雾干燥制备绿豆酸奶粉。该粉用水复原后,风味、色泽、营养价值与原料酸奶几乎没有差异。由于加入了保护剂,较好地保存了部分活菌,绿豆酸奶粉活菌数为6×106个/g。     

Nutritional,antioxidant, and antimicrobial assessment of carrot powder and its application as a functional ingredient in probiotic soft cheese

Carrots (the main source of carotenoids) have multiple nutritional and health benefits. The objectives of this study were to evaluate the compositional, antioxidant, and antimicrobial properties of carrot powder and to examine its effect on the sensory characteristics, chemical properties, and microbial viability of probiotic soft cheese at a rate of 0.2, 0.4, and 0.6%. The carrot was turned into powder before being analyzed and incorporated as an ingredient in making probiotic soft cheese. Probiotic soft cheese was made from buffalo milk. The buffalo milk (～6.9% fat, 4.4% protein, 9.2% milk solids not fat, and 0.7% ash) was pasteurized at 75 ± 1°C for 5 min and cooled to 40–42°C. The milk was then divided into 4 aliquots. Sodium chloride (local market, Assiut, Egypt) was added at a ratio of 5% followed by starter cultures. The carrot powder (4.5% moisture, 4.8% ash, 2.7% fat, 8.2% protein, 11.9% fibers, and 72.3% carbohydrate) was added at a rate of 0.2, 0.4, and 0.6%, followed by addition of 0.02 g/kg rennet. The cheese was cut again into cubes, pickled in jars filled with whey, and stored for 28 d at 6 ± 1°C. The results of this study illustrated the nutritional and antioxidant properties of carrot powder. Incorporation of carrot powder in probiotic soft cheese affected the moisture and salt content at 0 d. The total bacteria count decreased from 7.5 to 7.3 log cfu/g in the cheese when carrot powder was used at a rate of 0.6%. The reduction of total bacteria count was noticed during the 28 d of storage by adding carrot powder. Furthermore, lactic acid bacteria and Bifidobacterium longum counts elevated with adding carrot powder during the 28 d of storage.     

喷雾干燥速溶红枣粉工艺优化及其冲调性分析

以红枣为原料,通过单因素试验探究喷雾干燥进风温度、雾化器转速、进料流量对速溶红枣粉的分散性、润湿性、水分含量及颗粒粒度的影响,确定进风温度、雾化器转速、进料流量3个因素为自变量,分散时间和润湿时间为响应值进行响应面优化试验。结果表明喷雾干燥制备速溶红枣粉的最优参数为:进风温度170℃、进料流量1.3 L/h、雾化器转速400 r/s,在此条件下测得润湿时间为3.86 s,分散时间为2.27 s,与模型预测值相符。     

Review Article: Technological Aspects of Prebiotics in Probiotic Fermented Milks

Prebiotics are food components that exert beneficial effects on health of the host, associated with modulation of the intestinal flora via stimulating the growth and/or activity of the probiotics. One of the recommended ways to maintain high viable numbers of probiotic bacteria in the intestine as well as in the probiotic fermented milk products until the time of consumption is via the use of prebiotics. These compounds can also affect sensory profile, physicochemical and rheological characteristics, and economic properties of probiotic fermented milk products. In this article, technological aspects of prebiotics (viability of probiotics in the product as well as the physicochemical, rheological, sensory, and economic characteristics of product) in probiotic fermented milks are reviewed.