利用啤酒废酵母生产1,6-二磷酸果糖发酵工艺的研究

啤酒废酵母生产1,6 -二磷酸果糖发酵工艺进行了实验性探讨。正交试验结果表明:发酵液中氯化镁的浓度、pH是1,6 - 二磷酸果糖生产最主要的影响因素。最佳发酵参数为发酵温度37℃,葡萄糖浓度0.4mol/L,磷酸盐浓度0.4mol/L,pH6.5,有机溶剂的加量约6%。发酵液中1,6 -二磷酸果糖的量最高可达70.5mg/mL。     

由啤酒废酵母发酵提取1,6-二磷酸果糖的研究

探讨了由啤酒废酵母发酵提取1,6-二磷酸果糖（FI）P）的工艺。正交试验结果表明，发酵液中氯化镁的浓度、酸度是1，6-二磷酸果糖生产最主要的影响因素。最佳发酵参数为：发酵温度37℃，葡萄糖浓度为0．5mol／L。磷酸盐浓度0．4mol／L，酸度6．5，有机溶剂的加量约6％。1，6-二磷酸果糖在发酵液中的得率最高可迭69．8mg／mL。     

啤酒废酵母制备1,6-二磷酸果糖的研究

啤酒废酵母生产1,6-二磷酸果糖发酵工艺进行了试验性探讨。正交试验结果表明,啤酒废酵母发酵生产FDP的最佳工艺参数为:发酵体系中葡萄糖的加量为0.5mol/L、无机磷的浓度为0.4mol/L、pH6.5、转化时间6h。     

酒精酵母生物合成1.6-二磷酸果糖的条件优化研究

为优化酒精酵母F15菌株转化合成1,6-二磷酸果糖(FDP)的条件,在单因素试验基础上,采用Box-Benhnken设计响应面中心组合试验,建立FDP生物合成量随反应液初始pH值、葡萄糖浓度和磷酸二氢钠浓度变化的二次回归方程.结果表明:最适的转化条件为初始pH 8、葡萄糖11％、磷酸二氢钠7％,在此转化条件下,获得的最大FDP生物合成量为3.74 g/L.     

啤酒废弃物在制药工业中的应用

啤酒废弃物主要指啤酒废酵母和啤酒糟。在制药工业中,啤酒废弃物可作为原材料提取超氧化物歧化酶、1,6-二磷酸果糖、核酸、谷胱苷肽、葡聚糖、甘露聚糖、酒花素及复合磷酸酯酶等物质,具有广阔的应用前景。     

高产2,5-二甲基-4-羟基-3(2H)-呋喃酮(DMHF)酵母菌株的选育

从酒曲中筛选到1株高产2,5-二甲基-4-羟基-3(2H)-呋喃酮(DMHF)的酵母菌株(SX-21).高浓度NaCl和外源添加1,6-二磷酸果糖有利SX-21菌合成DMHF,其产量为100mg/L,达到文献报道的最高产量.经NTG诱变,筛选到1株突变株(NTG-SX-103),其产量提高到320 mg/L.SX-21菌株经18S rRNA鉴定为季也蒙毕氏酵母.     

分离纯化二磷酸果糖(FDP)的研究

研究了葡萄糖酶促磷酸化反应液中的二磷酸果糖经钙盐沉淀、草酸脱钙、树脂纯化和酒精-媒晶剂结晶法的工艺路线,通过单因素实验结合正交设计试验,优化工艺参数.试验研究表明,FDP钙盐的分离工艺参数为：pH=5.0,T=40℃,V（酒精）/V（水）=0.6,弱碱性阴离子RⅢ树脂在pH2.0吸附FDP,用0.05mol/L NaCl-0.01mol/L HCl洗脱无机磷等杂质,用0.5mol/L NaCl-0.1mol/L HCl洗脱FDP,FDP钠盐结晶工艺条件为pH 4.5、温度25℃、媒晶剂10%、酒精加量1.6倍、结晶时间6.5h.FDP总收率达75%,重结晶体纯度达99.5%.     

正交试验法优选香椿叶总黄酮的半仿生提取工艺

研究了香椿叶中总黄酮的半仿生提取最佳工艺条件。用正交试验法对香椿叶中总黄酮的半仿生法提取工艺进行了优选,以黄酮提取量为考察指标,考察提取温度、提取时间、料液比对总黄酮提取量的影响,得到的半仿生法提取的最佳工艺条件为:分别以pH2盐酸溶液和pH7.5、pH8.5的氯化氨-氨水的缓冲溶液作为提取液,料液比(香椿叶质量∶提取液体积)=1∶12,在80℃每次提取1h,提取3次;在此条件下,黄酮提取量为10.3417mg/g香椿叶。     

杏鲍菇多糖-钙螯合物的制备及其抗氧化活性

为提高杏鲍菇多糖的应用价值,试验采用水提醇沉的方法提取杏鲍菇粗多糖,以钙含量为指标,通过单因素试验和正交试验探究时间、温度、pH对杏鲍菇多糖-钙螯合物制备工艺的影响,分析其清除·OH、O2-·和DPPH·的能力.结果 表明,3个因素对杏鲍菇多糖-钙螯合物含钙量的影响程度为温度＞pH＞时间.杏鲍菇多糖-钙螯合物的最佳制备...     

关于批准裸藻等8种新食品原料的公告

2013年第4号根据《中华人民共和国食品安全法》和《新食品原料安全性审查管理办法》有关规定,现批准裸藻、1,6-二磷酸果糖三钠盐、丹凤牡丹花、狭基线纹香茶菜、长柄扁桃油、光皮梾木果油、青钱柳叶、低聚甘露糖为新食品原料。生产经营上述食品应当符合有关法律、法规、标准规定。特此公告。附件:裸藻等8种新食品原料     

关键环境因子对螺旋藻营养元素生物积累及有机化程度的影响

以钝顶螺旋藻为研究对象,通过在培养液中分别添加钙铁锌硒离子并结合调节螺旋藻细胞的生长环境条件以达到以上四种营养元素最大积累的目的,并对其在细胞内的有机化程度进行研究。结果表明:与对照组相比,当温度为20 ℃、光照12 kLux、pH8.5时,钙积累量提高了97%,螺旋藻钙总含量和其有机化程度分别达到18.21 mg/g、84.17%;当温度为30 ℃、光照4 kLux、pH10.5时,铁积累量提高了175%,螺旋藻铁总含量和其有机化程度分别达到1634.34 ppm、89.98%;当温度为30 ℃、光照8 kLux、pH8.5时,锌积累量提高了87%,螺旋藻最高锌含量和有机化程度分别达到88.30 ppm、58.28%;当温度为30 ℃、光照12 kLux、pH9.5时,螺旋藻中硒元素总含量及有机化程度分别为1011.00 ppm、70.54%。因此,在以环境调控为基础,同时配合增加外源培养液浓度的培养条件下,能够使得螺旋藻钙、铁、锌、硒四种矿物质营养离子积累量大大增加。     

Acid-induced gelation of whey protein polymers: effects of pH and calcium concentration during polymerization

Heating whey protein dispersions (90°C for 15 min) at low ionic strength and pH values far from isoelectric point (pH>6.5) induced the formation of soluble polymers. The effect of mineral environment during heating on the hydrodynamic characteristics and acid-induced gelation properties of polymers was studied. Whey protein dispersions (80 g/l) were denatured at different pH (6.5–8.5) and calcium concentrations (0–4 mm) according to a factorial design. At pH 6.5, the hydrodynamic radius of protein polymers increased with increasing calcium concentration, while the opposite trend was observed at pH 8.5. Intrinsic viscosity results suggested that heating conditions altered the shape of protein polymers. Whey protein polymers were acidified to pH 4.6 with glucono-δ-lactone and formed opaque particulate gels. The storage modulus and firmness of gels were both affected by conditions used to prepare protein polymers. As a general trend, polymers with high intrinsic viscosity produced stronger gels, suggesting a relationship between polymer shape and gel strength.Acid gelation properties of whey protein polymers makes them suitable ingredients for yoghurt applications. Using whey protein polymers to standardize protein content increased yoghurt viscosity to 813 Pa.s while using skim milk powder at same protein concentration increased yoghurt viscosity to 393 Pa.s. Water holding capacity of protein polymers in yoghurt was 19.8 ml/g compared to 7.2 ml/g for skim milk powder protein. Acid gelation properties of whey protein polymers are modulated by calcium concentration and heating pH and offers new alternatives to control the texture of fermented dairy products.     

机械浆中胶体树脂沉积行为及影响因素

以脂肪酸、树脂酸、甘油三脂为模型物，研究了不同树脂组分、pH值、钙离子和温度对树脂沉积行为的影响，以及在钙离子存在下pH值对酸性组分沉积物组成的影响。结果表明，无钙离子存在时，低pH值时树脂沉积较严重，随pH值的升高，沉积趋势降低；钙离子的存在，加剧了树脂的沉积。pH值是影响酸性组分形成钙皂的关键因素，低pH值时沉积物中几乎不含有钙皂，随pH值的升高，沉积物中钙皂的含量提高，并且沉积物的黏性显著增加。甘油三脂沉积物中几乎不含无机成分，但在pH值4．5～8．5范围内，钙离子的存在明显加剧了其沉积行为。温度对树脂酸组分影响较大，温度升高，树脂酸黏性提高，沉积性增加。     

Effects of milk pH alteration on casein micelle size and gelation properties of milk

The effects of changes in pH above and below the natural pH of milk (ca 6.6) on the casein micelle size and the gelation properties of the pH adjusted and restored samples were investigated. The size of casein micelles increased at pH 7.0 and 7.5, then started to decrease above pH 8.5. It is postulated that at pH below 8.5 the casein micelles swell, while elevated pH causes their dissociation. Conversely, the size of casein micelles decreased on acidification to pH 5.5 and increased when the pH dropped below 5.5, due to the shrinkage of casein micelles at lower pH before their aggregation at pH below 5.5. In response to neutralising treated milk back to normal milk pH of 6.6, it was found that the casein micelle size of treated milk with a narrow range of pH change between 6.0 and 7.0 was reversible, while beyond this range the structure of casein micelles became irreversible. The restoration of casein micelle size was followed by the restoration of some parameters such as soluble calcium, ethanol stability, and milk whiteness. Acid-induced gelation did not change the elastic modulus, while rennet-induced gelation was affected by initial milk pH. In reference to the size of reversible range elastic modulus (G’) of acid or rennet gels made from restored milk, the sizes were similar to control milk after 6 h of gelation.     

Precipitation Behavior of Extracted Nitrogen, Phytic Acid and Minerals in Rapeseed Flour Modified by Acylating Agents

The first and second aqueous extracts of unmodified and highly succinylated (63%) or acetylated (87%), dehulled, defatted rapeseed flour (RF) were prepared. Lowering of their pH from 8.5 to the isoelectric pH increased the nitrogen and phytic acid precipitation yields while decreasing the percent bound calcium suggesting that phytic acid coprecipitated with the protein with little or no mediation by calcium. Acylation lowered the isoelectric pH of the protein, increased the total nitrogen precipitation yield and reduced the phytic acid yield from RF. Isoelectric precipitation or dialysis gave 43–67% yield of low phytate protein from the first extract and 8–11% yield of high phytate protein from the second extract.     

松香-聚胺中碱性施胶的初步探讨

将5种不同结构的聚胺用于分散松香中碱性施胶体系,比较各种聚胺对施胶效果的作用,得出中碱性范围内松香-聚胺体系应用的最佳pH值,并在此pH值下,对胶料留着、铝离子留着和碳酸钙留着进行了研究,另外对聚胺的增强作用也做了初步研究,并分析了松香-聚胺体系的施胶作用、留着作用及增强作用机理.     

微波辅助萃取鹌鹑蛋黄卵磷脂研究

研究相关因素,如萃取液pH值、料液比、微波辐射功率与时间等,对微波辅助萃取鹌鹑蛋黄卵磷脂效果的影响。以鹌鹑蛋黄为原料,95％无水乙醇为萃取剂,在单因素水平试验的基础上进行正交试验,优化微波辅助萃取鹌鹑蛋黄卵磷脂最佳工艺条件：95％乙醇的pH值8．5,料液比1：4,辐射功率650W,辐射时间40s．     

Potential use of fruit waste containing in vivo De-esterified pectin as a thickener in canned products

Orange peel and tomato skins were treated with sodium carbonate to pH 8.5 to cause in vivo pectin de-esterification principally by pectinesterase action. The resulting material was dried and powdered and then evaluated for thickening properties in canned systems. It was found that after autoclaving for 75 min at 121.1 °C in a rotating retort in the presence of guar gum, sodium tripolyphosphate and calcium sulphate dihydrate, high post process viscosities could be obtained when orange peel was included at a concentration of 0.5% provided the pectin degree of esterification was reduced below 20% and the intrinsic viscosity of the pectin measured after extraction was above 3 dl g^?1. Thickening was also obtained with tomato skins providing these two conditions were fulfilled. The dependence of viscosity on the calcium level and the thixotropic nature of the solutions obtained after processing, demonstrate that a calcium pectate gel can be formed even after severe heat treatment at a neutral pH. It is suggested that fruit and vegetable material containing in vivo deesterified pectin may be of value as a thickener in canned foods.     

从米糠中提取植酸钙的工艺研究

对米糠中提取植酸钙的工艺进行了研究.以酸浸pH值、浸泡时间、液料比为影响因素,进行了3因素3水平正交试验.经多次重复试验,结果表明最佳工艺为:酸浸pH值2.0,浸泡时间5h,液料比8∶1;在最佳条件下,植酸钙的提取率为9.06％.通过对植酸钙标准品和所提取物质的红外谱图的比较,证实所提取物质为植酸钙粗品.     

Fermentation of calcium-fortified soymilk with Lactobacillus: effects on calcium solubility, isoflavone conversion, and production of organic acids

ABSTRACT:  The objective of this study was to enhance calcium solubility and bioavailability from calcium-fortified soymilk by fermentation with 7 strains of Lactobacillus , namely, L. acidophilus ATCC 4962, ATCC33200, ATCC 4356 , ATCC 4461 , L. casei ASCC 290, L. plantarum ASCC 276, and L. fermentum VRI-003. The parameters that were used are viability, pH, calcium solubility, organic acid, and biologically active isoflavone aglycone content. Calcium-fortified soymilk made from soy protein isolate was inoculated with these probiotic strains, incubated for 24 h at 37 °C, then stored for 14 d at 4 °C. Soluble calcium was measured using atomic absorption spectrophotometry (AA). Organic acids and bioactive isoflavone aglycones, including diadzein, genistein, and glycetein, were measured using HPLC. Viability of the strains in the fermented calcium-fortified soymilk was > 8.5 log₁₀ CFU/g after 24 h fermentation and this was maintained for 14-d storage at 4 °C. After 24 h, there was a significant increase ( P < 0.05) in soluble calcium. L. acidophilus ATCC 4962 and L. casei ASCC 290 demonstrated the highest increase with 89.3% and 87.0% soluble calcium after 24 h, respectively. The increase in calcium solubility observed was related to lowered pH associated with production of lactic and acetic acids. Fermentation significantly increased ( P < 0.05) the level of conversion of isoflavones into biologically active aglycones, including diadzein, genistein, and glycetein. Our results show that fermenting calcium-fortified soymilk with the selected probiotics can potentially enhance the calcium bioavailability of calcium-fortified soymilk due to increased calcium solubility and bioactive isoflavone aglycone enrichment.