稻壳吸附剂生产技术

稻壳是稻米加工重要副产物之一,但由于其特殊物理性质,对其综合利用较低;该文综述稻壳及稻壳灰在生产吸附剂方面研究及应用,并对其前景进行展望。     

酸化稻壳灰吸附剂制备及脱色性能的研究

稻壳灰经硫酸活化处理制备酸化稻壳灰吸附剂,对废煎炸油进行吸附脱色实验,并与活性白土吸附法进行了对比。结果表明,酸化稻壳灰吸附剂具有明显的吸附脱色效果,其脱色最佳工艺条件为:酸化稻壳灰用量7%,脱色温度80℃,脱色时间20～25 min,脱色油平均色泽为Y30、R5.9。酸化稻壳灰制备原料廉价易得,制备工艺简单,成本低,可代替活性白土用于脱除废煎炸油中的游离脂肪酸和色素。     

白腐菌预处理稻壳灰吸附性能研究

采用扫描电镜观察和BET检测法,发现经白腐菌处理过的稻壳制备稻壳灰比未处理的稻壳灰的比表面提高很大,结果表明其比表面提高了2.43倍。同时对此稻壳灰的吸附动力学进行了研究。配制不同浓度的亚甲基蓝溶液,在不同温度下加入此活性稻壳灰,每隔一定时间测经稻壳灰脱色后的亚甲基蓝溶液的吸光度。研究时间和温度对吸附剂吸附性能的影响,探讨活性稻壳灰对亚甲基蓝吸附动力学行为,得到了吸附等温线。根据试验数据进行一级动力学方程和二级动力学方程拟合,结果表明二级动力学方程能更好地表示稻壳灰吸附性能。     

稻壳灰在油脂精炼中应用

<正>稻壳灰是以稻壳为原料经一定工艺处理制成灰状物,在电子显微镜下观察,其颗粒结构为整齐排列的蜂窝状,这种蜂窝状结构的骨架主要由二氧化硅和少量钠盐钾盐组成,在骨架中间的蜂窝内充填着无定型碳,具有很强的吸附能力,其吸附效果比单一结构的硅酸盐要强得多。利用不同的工艺制成的稻壳灰用途不同,碱性制品用于脱酸,而酸性制品用于脱色。下面简介一个稻壳灰的制备及在油脂精炼中应用。     

由稻壳灰制备活性炭的研究

稻壳经适当燃烧产生煤气后可获得稻壳灰。利用碱与稻壳灰中所含二氧化硅反应，将其中大部分二氧化硅溶出，生成多孔性稻壳灰进而可制备活性炭。现研究了影响活性炭质量的多种因素。实验结果表明，在最佳条件下所得活性炭产品质量符合国家产品标准。     

稻壳灰的结构和组成的扫描透视分析——稻壳灰研究之三

本文继稻壳灰成份、组织结构及作吸附研究之后,又对稻壳灰的结构和组成进行扫描透视分析,从而进一步掌握稻壳灰做吸附剂效果。     

利用稻壳灰制取硅酸钾技术简介

加工大米时一般可得到约20％的副产品稻壳，稻壳在粮油加工厂中主要用作燃料，每100kg稻壳燃烧后可得到的灰渣量约为20kg，稻壳灰中的化学组成如下表：稻壳灰的化学成分从表中可以看出，SiO2含量很高，而磷和钾的含量相对太低，故稻壳灰不适合作肥料。有报道可将稻壳灰用作炼钢     

稻壳灰制高纯二氧化硅的研究

利用稻壳灰与氢氧化钠溶液反应制得的硅酸钠溶液和硫酸反应得二氧化硅，再经酰洗、水洗，干燥和燃烧得高纯二氧化硅，并研究了各种因素对二氧化硅中杂质的影响。     

稻壳灰制水玻璃的正交试验研究

利用稻壳灰与NaOH溶液反应制备水玻璃.采用正交试验设计,研究NaOH溶液质量分数、物料比(NaOH溶液与稻壳灰的质量比)、反应时间和反应温度对siO2溶出率和水玻璃模数的影响.对正交试验结果进行了极差分析和方差分析,两种分析方法得出的结论一致.最优方案为为NaOH溶液质量分数为20%,物料比为3:1,反应时间4 h,反应温度100℃.经试验验证,最优方案的溶出率和模数分别达到95.74%和3.3,为最优试验结果.     

稻米中脂肪酸值测定方法的研究

建立了稻米中脂肪酸值的滴定新方法。样品以石油醚提取后，过滤，加入50％乙醇溶液，以酚酞为指示剂，用KOH标准溶液滴定至下层溶液呈微红色。该方法回收率为96．66％-100．77％，相对标准偏差为0．29％-3．56％。本方法的选择性和精密度均优于乙醇提取法，滴定终点变化敏锐。     

微波加热对米糠稳定性影响的实验研究

本文对微波加热稳定米糠的工艺参数，微波处理时间、料层厚度、米糠原始水分、储藏时间对米糠稳定性的影响进行了试验。结果表明，微波处理时间150—200s、料层厚度30—70mm、初始水分为15．8％—21％的米糠，经微波处理后强化贮藏，6周内游离脂肪酸(FFA)的增长率在12％以下。     

米糠油脱酸工艺和方法研究进展

米糠油传统的化学碱炼脱酸工艺存在明显不足,国内外米糠油脱酸工艺方法研究非常活跃,并且有些方法已经开始应用于实际生产。本文归纳了米糠油脱酸工艺与方法的研究进展。对国内外现有的几种脱酸方法进行了分析比较,并总结了各自存在的问题,为进一步系统研究米糠油脱酸工艺提供了线索和依据。     

The form more than the fatty acid profile of fat supplements influences digestibility but not necessarily the production performance of dairy cows

The form of a lipid supplement, its degree of saturation, and its fatty acid (FA) profile greatly influence digestibility and cow productive response. The objective in this study was to examine the effect of fat supplements that differ in their form or FA profile on nutrient digestibility and cow performance. Forty-two mid-lactation cows (128 ± 53 d) were assigned to 3 treatment groups according to milk yield, days in milk, and body weight. For 13 wk, the cows were fed rations that contained (on a dry matter basis) (1) 2.4% of calcium salts of fatty acids (CSFA) consisting of 45% palmitic acid (PA) and 35% oleic acid (OA; CS45:35); (2) 2.4% of CSFA consisting of 80% PA and 10% OA (CS80:10); or (3) 2.0% of free FA consisting of 80% PA and 10% OA (FF80:10). Rumen samples were taken to measure the ammonia and volatile FA concentrations, and fecal samples were taken to measure the digestibility. Preplanned comparisons were CS45:35 versus CS80:10 to assess 2 CSFA supplements with different FA profiles, and CS80:10 versus FF80:10 to assess similar FA profiles in different forms. Compared with CS45:35, CS80:10 decreased the milk yields, increased the fat percentage, and tended to increase the energy-corrected milk (ECM) yields. The fat percentage of milk was highest in the FF80:10 cows (4.02%), intermediate in the CS80:10 cows (3.89%), and lowest in the CS45:35 cows (3.75%). Compared with CS80:10, FF80:10 increased milk yields (50.1 vs. 49.4 kg/d, respectively), tended to increase fat percentage, and increased 4% fat-corrected milk (4% FCM; 49.1 vs. 47.7 kg/d, respectively) and ECM yields (49.5 vs. 48.2 kg/d, respectively). Treatment had no effect on dry matter intake (DMI), and compared with CS80:10 cows, the calculated energy balance was lower in the FF80:10 cows. The 4% FCM/DMI and ECM/DMI ratios were higher in the FF80:10 group compared with the CS80:10 group. Compared with the CS80:10 cows, the FF80:10 cows had a lower rumen pH, higher propionate, lower acetate/propionate ratio, and higher total VFA. Compared with CS45:35 cows, the apparent total-tract digestibilities of neutral detergent fiber and acid detergent fiber were higher in CS80:10 cows; whereas, the apparent total-tract digestibilities of dry matter, organic matter, protein, neutral detergent fiber, and acid detergent fiber were higher in the CS80:10 cows compared with the FF80:10 cows. Compared with the CS80:10 group, the apparent digestibility of total FA was 13.0 percentage points lower in the FF80:10 cows (79.1 vs. 66.1%, respectively), and similarly, the digestibilities of 16-carbon and 18-carbon FA were lower in the FF80:10 cows than in the CS80:10 cows. In conclusion, the form, more than the FA profile of fat supplements, influenced digestibility. Further, the CSFA supplements were more digestible than the free fatty acids, regardless of the FA profile. However, energy partitioning toward production appeared to be higher in the FF80:10 cows, although the digestibility of nutrients was lower than in the CSFA product with a similar FA profile.     

全脂米糠的挤压稳定性

以游离脂肪酸及过氧化值为指标 ,研究了不同挤压工艺条件对米糠稳定性的影响 .结果表明 ,适宜的全脂米糠稳定条件是挤压温度为 12 5～ 135℃、原料水分为 16%～ 18%、螺杆转速为 180r/min ,稳定化的米糠更适合下一步的提取工艺 .     

油茶蒲水提物的减肥作用

脂肪酸合酶是治疗肥胖症的潜在靶点。研究发现油茶蒲水提物对脂肪酸合酶有很强的可逆抑制和不可逆抑制作用,其对脂肪酸合酶的半抑制浓度仅为1.72μg/mL。在一个油茶蒲水提物浓度为25μg/mL的酶-抑制剂混合体系中,180 min后脂肪酸合酶的剩余活性不到30%。同时小鼠预防性肥胖试验结果显示,300 mg/kg油茶蒲水提物能显著降低小鼠的体重增加率、体脂比和肝脏的脂肪酸合酶活性,且作用效果强于阳性对照奥利司它。研究结果显示,油茶蒲水提物具有作为控制肥胖的功能性成分开发的潜力,这可能与其对脂肪酸合酶的抑制作用有关。     

混合型大豆干酪成熟特性的研究

对混合型大豆干酪的成熟特性进行了研究。检测了混合型大豆干酪成熟过程中游离脂肪酸和氨基酸含量的变化,在扫描电镜下观察了不同成熟条件下干酪的微观结构。结果表明,成熟温度对游离脂肪酸含量影响不显著,对游离氨基酸含量影响显著;随着成熟时间的延长,饱和脂肪酸与不饱和脂肪酸含量之比下降,游离氨基酸含量变化较为显著;成熟对混合型大豆干酪的微观结构影响很大,使得干酪质地越来越致密均匀。