菠萝果酒酵母筛选及发酵性能测试

从不同成熟度的菠萝皮中分离酵母菌,通过一级筛选,得到45株产香和产酒较好的菌株,再通过杜氏管法筛选得到发酵速度较快的12株产香和产酒较优良的优势菌,三级筛选是将这12株菌接种到菠萝汁发酵液中,筛选出一株适合菠萝汁发酵的产酒和产香性能较优的菌株。并对该菌株的温度、pH值、初始糖度、SO2及酒精度耐受性进行了测试。结果表明,35℃以上的温度条件下酵母菌酒精产率下降,30℃产酒率最高;pH5.0酵母菌酒精达到最大;初糖浓度超过25°Be就对酵母菌产生抑制;SO2添加量为60mg/L时,酒精产率提高,产酒率随着添加量继续增加而减小;发酵液中酒精体积分数达到5%时,酵母菌的生长受到抑制,当达到8%,抑制效果加剧,超过11%以后,基本达到酵母菌的耐受极限。     

ISOLATION AND SELECTION OF ETHANOL-RESISTANT AND OSMOTOLERANT YEASTS FROM REGIONAL AGRICULTURAL SOURCES IN MEXICO

In Mexican alcohol distilleries using sugarcane molasses, one reason for low alcoholic fermentation efficiency is the use of inferior yeast cultures. The objective of the present study was to isolate and select yeast strains from alcoholic fermentations of natural sources (sugarcane molasses, grape juice, cane juice and pineapple) from Veracruz city market and Mexican distilleries, and to evaluate their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Ethanol production, glucose composition, growth rate, "Killer" activity, ethanol and glucose tolerance of the most promising strains were monitored on synthetic and molasses media. A total of 112 yeast strains were isolated by their capacity to produce ethanol, and from these, only 58 were selected on the basis of best ethanol theoretical yields (88–96%). These strains were exposed several times to high concentrations of glucose and ethanol in order to select ethanol- and glucose-tolerant yeast; 10 were obtained that adapted best to these conditions and that showed "Killer" activity. Of these strains, U3-11, M11, JC10 and U2-10 (obtained from grape juice, sugarcane molasses and cane juice) demonstrated the highest adaptation to both ethanol (5–7% w/v) and glucose (20% w/v). The maximum yield obtained was 0.46 g/g (90% theoretical yield) in a 20-L bioreactor with cane molasses under nonsterile conditions.

PRACTICAL APPLICATIONS

The selected yeasts could be introduced into industrial processes in Mexican distilleries using sugarcane molasses in order to improve productivity and diminish contamination problems.     

Production of ethanol from liquefied cassava starch using co-immobilized cells of Zymomonas mobilis and Saccharomyces diastaticus

Co-immobilized cells of Saccharomyces diastaticus and Zymomonas mobilis produced a high ethanol concentration compared to immobilized cells of S. diastaticus during batch fermentation of liquefied cassava starch. The co-immobilized cells produced 46.7 g/l ethanol from 150 g/l liquefied cassava starch, while immobilized cells of yeast S. diastaticus produced 37.5 g/l ethanol. The concentration of ethanol produced by immobilized cells was higher than that by free cells of S. diastaticus and Z. mobilis in mixed-culture fermentation. In repeated-batch fermentation using co-immobilized cells, the ethanol concentration increased to 53.5 g/l. The co-immobilized gel beads were stable up to seven successive batches. Continuous fermentation using co-immobilized cells in a packed bed column reactor operated at a flow rate of 15 ml/h (residence time, 4 h) exhibited a maximum ethanol productivity of 8.9 g/l/h.     

榴莲菠萝果酒酿造研究

采用高活性葡萄酒干酵母,将榴莲果肉以适当比例与菠萝果汁一起发酵,酿制出融榴莲和菠萝香味一体、风味独特的榴莲菠萝果酒。对榴莲菠萝果酒酿制工艺条件、榴莲添加量、添加方式及菠萝品种、果汁成分调整进行了研究。     

模糊数学在菠萝果乳固体饮料制备中的应用

以大豆油为芯材,菠萝果汁及其他材料为壁材,结合微胶囊技术采用喷雾干燥制备新型的菠萝果汁粉末油脂,并以菠萝果汁粉末油脂为原料,添加乳粉、白砂糖及柠檬酸以模糊数学感官评价法采用正交实验配制新型的菠萝果乳固体饮料。结果表明,菠萝果汁固体饮料较优的配方为:菠萝果汁粉末油脂20g、乳粉12g、白砂糖16g、柠檬酸0.1g,热水冲融后为均匀细腻乳状液,气味宜人,酸甜可口。     

响应面法优化甘蔗菠萝复合型果酒的酿造工艺

以甘蔗和菠萝为原料制作复合型果酒,以感官评价为考察指标,在单因素试验的基础上,通过响应面法优化甘蔗菠萝复合型果酒的酿造工艺。结果表明,甘蔗菠萝复合型果酒的最佳酿造工艺为：甘蔗汁与菠萝汁配比1∶2（V/V）、白砂糖添加量225 g/L、发酵时间7 d、酵母接种量100 g/L、发酵温度26 ℃。在此优化条件下,甘蔗菠萝复合型果酒色泽金黄,澄清透明,感官评分为96.5分,酒精度为10.84%vol,pH值为4.13,糖度为10 °Bx,浊度值为57.9 JTU,细菌总数为75个/mL,其品质指标均符合国家相关标准。     

半干型菠萝果酒发酵工艺条件优化

以菠萝为原料发酵生产半干型菠萝果酒。通过单因素试验考察了不同的初始糖度、酵母接种量、发酵液pH值及发酵时间对菠萝果酒品质的影响,采用正交试验优化工艺条件,通过验证得出最佳工艺条件：初始糖度为22%,初始pH值为4.0,接种量为9%,发酵时间为8 d,发酵温度控制在25～29℃。菠萝酒中检测分析出18种香味成分,其中酯类6种、醇类5种、烷类4种,酚类1种,喹啉类1种,呋喃类1种。在此最佳工艺下酿制而成的菠萝果酒酒精度达14%vol,含糖量7.4 g/L,成品酒澄清透亮,酒体丰满,口感醇厚,酸甜适中,具有浓郁的菠萝果香和独特的酒香。     

甜瓜菠萝起泡果酒酿造工艺的研究

以甜瓜、菠萝作为原料,对酿造复合型起泡酒的工艺进行研究。通过单因素试验及正交试验确定了甜瓜菠萝起泡酒的最佳工艺条件：甜瓜与菠萝的质量比为1∶1,安琪酿酒酵母与SC1230专用酿酒酵母的添加比例为1∶1,接种量0.3 g/L,发酵醪的初始糖度为26%,β-环糊精添加量0.3%,采用罐内发酵方式对起泡酒进行充气。最终制得的甜瓜菠萝起泡酒感官评分为95分,酒精度11.4%vol,残糖4.3 g/L,总酸5.0 g/L,压力0.33 MPa,微生物指标合格。产品色泽金黄透亮,果香和酒香协调,酸甜爽口,饶有余味。     

Fermented sugarcane and pineapple beverage produced using Saccharomyces cerevisiae and non‐Saccharomyces yeast

The potential of Saccharomyces cerevisiae (strains UFLA CA11 and UFLA FW15) and Pichia caribbica (UFLA CAF733) to produce a fermented sugarcane and pineapple drink was evaluated. Co‐ and pure cultures using different proportions of sugarcane juice and pineapple pulp (80:20, 70:30 and 60:40) were prepared. The sugar concentration of the must was adjusted to 16° Brix and was inoculated with approximately 7 log CFU/mL. After a preliminary test and based on higher concentrations of desirable volatile components, low production of acetic acid, high production of ethanol, and kinetic parameters, P. caribbica was chosen to perform the fermentation in 5 L batches. The fermentation performed with P. caribbica in the proportion of 60:40 showed a yield in ethanol of 0.45 g/g, an ethanol productivity of 1.32 g/L/h and a fermentation efficiency of 88.22%. The maximum ethanol concentration was 79.78 g/L and P. caribbica increased concentrations of desirable volatile compounds, such as 2‐phenyethanol, 2‐methyl‐1‐propanol, 3‐methyl‐1‐butanol, ethyl acetate and phenylethyl acetate. Copyright © 2015 The Institute of Brewing & Distilling     

绿豆菠萝复合饮料工艺的研究

通过对绿豆菠萝复合饮料加工工艺的研究,得出浸泡绿豆的最佳工艺参数为0.25％碳酸氢钠溶液以1：4料液比在20℃下浸泡10h;脱腥的最佳工艺参数为100℃沸水煮制3min;风味调配的最佳配方为1000ml绿豆乳、150ml菠萝原汁100g白砂糖、0．4g柠檬酸。     

菠萝果酒的发酵工艺研究

通过以菠萝为主发酵原料,采用安琪活性干酵母生产菠萝果酒,发酵过程中采用正交试验,优化工艺过程中的关键性因素,最终获得了一种色、香、味、外观俱佳的菠萝酒.并通过研究得出生产菠萝酒的最佳工艺条件:即以酒精度为评价指标的最佳发酵条件组合为:发酵温度24℃,干酵母接种量0.2 g/L,菠萝汁糖度24°Bé;以感官评价为指标的最...     

Optimization and interaction of media components in ethanol production using Zymomonas mobilis by response surface methodology

Ethanol production using Zymomonas mobilis strains with medium optimized by response surface methodology (RSM) was studied. A significant improvement in the ethanol yield (0.50 g/g ethanol) was demonstrated, resulting in very low residual sugar and fewer by-products. The five-factor and five-response full factorial design have shown that glucose and yeast extract are the key media components that influence ethanol production, followed by the inoculum concentration and ammonium sulfate, with phosphate showing little or no effect. The composition (all in g/l) of the optimized medium was glucose 120.4, ammonium sulfate 0.96, potassium dihydrogen phosphate 0.02, yeast extract 6.5, and magnesium sulfate 0.5. The optimum inoculum concentration was log10 8.4 cells.     

菠萝酸豆奶的理化性质及糖代谢研究

由菌种XPL-1发酵制备酸豆奶SY、SYP（加菠萝汁）、SYB（加蛋白酶）和SYPB（加菠萝汁和蛋白酶）,并研究了样品的理化性质、流变学特性以及糖的代谢作用。结果表明菠萝汁的应用显著促进菌种产酸,菠萝蛋白酶的应用明显提高酸豆奶的持水力,改善酸豆奶的流变学性质,其中SYPB的酸度值和持水力最高,分别达到65.76 °T和84.70%,屈服应力τ0最低,为3.71 Pa。进一步的代谢研究发现,乳酸菌发酵时可能优先利用蔗糖,同时还能利用部分果糖、水苏糖和棉子糖,产生大量的乳酸和少量的醋酸,其中样品SYPB产生7.85 mg/mL的乳酸和0.38 mg/mL的醋酸;感官评价的结果表明,SYPB的滋味和质构得分最高,总体可接受性最好,表明菠萝汁和菠萝酶的应用均有利于酸豆奶口感的改善。     

Efficient very‐high‐gravity fermentation of sugarcane molasses by industrial yeast strains

In this study industrial strains were inoculated, in successive cycles, at high cell density into a sugarcane‐based juice containing normal (22%, w/v) and very high sucrose (30%, w/v) levels and supplemented with peptone as a nitrogen source. At 30 °C, in shaken cultures, in the normal gravity situation, efficient sucrose utilization occurred in both the supplemented and unsupplemented medium. At higher sugar concentrations, supplementation with peptone induced a more efficient fermentation compared with the unsupplemented medium, with higher biomass accumulation and maintenance of cell viability, and ethanol levels as high as 16% (v/v). Trehalose was also high during the cycles, probably as a necessary response of the yeast to the high stress fermentation conditions. This suggests that it is possible to increase ethanol production by using very‐high‐fermentation technology and that nutritional supplementation would have a positive effect on the fermentation, allowing for efficient sugar consumption and cell viability maintenance. Copyright © 2016 The Institute of Brewing & Distilling     

棕苞、菠萝复合饮料的研制

采用单因素试验和正交试验,对棕苞、菠萝复合饮料的加工工艺和配方进行了研究。结果表明,最优调配比例为棕苞汁：菠萝汁：水=3：3：4;复合饮料最优配方为：黄原胶．2％、．2％、舒砂罩竹3％。以此配方做出的饮料色泽鲜艳,具有较好的口感,有菠萝特有的芳香,口感细腻,酸甜可口。     

植物乳杆菌和酿酒酵母发酵菠萝汁的性能比较及产物分析

采用植物乳杆菌（Lactobacillus plantarum）和酿酒酵母（Saccharomyces cerevisiae）分别进行单菌与混菌发酵菠萝汁,并比较分析不同接菌方式下菠萝汁的发酵性能及发酵体系中的产物。结果表明,相同接种量发酵72 h后,植物乳杆菌单独发酵活菌数可达108 CFU/mL,分别约为酿酒酵母单独发酵和二者混合发酵活菌数的3倍和10倍;植物乳杆菌的接入使发酵液pH降至3.21,而酿酒酵母的接入使菠萝汁中氨基酸态氮降至3.15×10-4 mg/L,糖类物质几乎被消耗殆尽。发酵产物分析结果发现,植物乳杆菌单独发酵产生大量乳酸（每升增加12.02 g/L）和少量乙酸（每升增加0.40 g/L）,影响了口感,而酿酒酵母单独发酵则使菠萝汁中原有的香气物质损失较多（4种）。综合分析,采用二者混合发酵,既可保有菠萝本身的营养物质和特有香气,又可赋予其一定的发酵风味,获得口感良好的菠萝发酵饮品。     

Food uses of pineapple waste and by-products: a review

Waste from fruits and vegetable processing industry is produced in large quantities worldwide and it contains high levels of lignocellulose, fibre, sugar, bioactive and functional compounds. Their utilisation has become one of the main important and challengeable aspects due to the generation of large quantities of by-products including peels, seeds, leaves and unused flesh in different steps of processing chain. Many researches have validated the waste utilisation as novel, low-cost, economical and natural sources of dietary fibre, antioxidants, pectin, enzymes, organic acids, food additives, essential oils, etc. through different methods of extractions, purifications and fermentations. Though, obtaining these by-products from such a variable substrate requires an understanding of the composition of the polysaccharides and their associations within the overall substrate. Focus on the pineapple fruit, scientific and technological studies have already highlighted and confirmed the potential of better and more profitable markets for pineapple wastes. This review is first of all the collection of previous reports about valorisation of food processing waste, deepening the possibilities of pineapple waste utilisation and to promote the integral exploitation of the by-products rich in bioactive compounds, even as multifunctional food ingredients. More in detail, this review aims at identifying those processes that can be implemented even in disadvantaged areas by means of technologies that allow recovering waste directly on site, thus reducing pollution and providing ingredients/food products with high nutritional values that could be integrated into the diet.     

高浓麦汁中添加红枣汁对酵母发酵性能及啤酒风味的影响

该实验研究了红枣汁不同添加量（10%、15%、20%、25%、30%、35%）对啤酒高浓酿造中酵母发酵性能及风味物质的影响。结果表明,红枣汁的添加能显著提高酵母的发酵性能,发酵过程中红枣汁添加组总CO2质量损失均高于对照组,发酵结束后乙醇产量显著增加（P＜0.05）,其中,30%红枣汁添加量促发酵效果最好,发酵度为88.18%,酒精度为11.30%vol,与对照组相比,分别提高了4.16%和4.63%。添加红枣汁可显著影响啤酒的色值：红枣汁添加比例越高,啤酒L*值越低,a*值与b*值越高,总色差（ΔE值）与对照组差异越大。与对照组相比,红枣汁的添加减少了高级醇的形成,显著降低了啤酒的醇酯比。     

菠萝浓缩汁在储藏过程中美拉德褐变及其反应动力学研究

研究了两种不同加工工艺生产的菠萝浓缩汁(菠萝果肉浓缩汁和菠萝全果浓缩汁)在储藏过程中的美拉德褐变及其反应动力学,并进一步探讨了美拉德反应对菠萝浓缩汁非酶褐变的影响。结果表明,菠萝浓缩汁在储藏期间,美拉德褐变遵循一级反应动力学;菠萝果肉浓缩汁和菠萝全果浓缩汁在储藏期间美拉德褐变的活化能分别为36.19kJ/mol和29.54kJ/mol。HMF积累对果汁非酶褐变的影响主要作用在储藏后期。     

温度对运动发酵单胞菌乙醇产量及动力学参数的影响

培养温度对运动发酵单胞菌有很大的影响。本文研究了在20℃～40℃范围内培养运动发酵单胞菌时,其生物量、乙醇产量、残糖量等指标的变化情况,并研究了在不同温度下在对数生长期间各项动力学参数的变化。运动发酵单胞菌的最适培养温皮为30℃～33℃,在这一范围内,比乙醇产率、比生长速率、葡萄糖比消耗速率等各项指标都较好。