Effect of corn particle size on site and extent of starch digestion in lactating dairy cows

Two experiments were conducted to determine the effects of corn particle size (CPS) on site and extent of starch digestion in lactating dairy cows. Animals were fitted with ruminal, duodenal, and ileal cannulas. Dry corn grain accounted for 36% of dry matter intake. In experiment 1, 6 cows were used in a duplicate 3 x 3 Latin square design. Semiflint corn was used. Corn processing methods were grinding, medium rolling, and coarse rolling. The mean particle size of the processed corn was 730, 1807, and 3668 microm, respectively. Rumen digestibility of starch linearly decreased from 59% with ground corn to 36% with coarsely rolled corn. Similarly, small intestine digestibility linearly decreased with increased CPS, and consequently, the amount of starch digested in the small intestine was not affected by corn processing. In experiment 2, 4 cows were used in a 2 x 2 crossover design. Dent corn was used. Corn processing methods were grinding and coarse rolling. The mean particle size of the processed corn was 568 and 3458 microm, respectively. Rumen digestibility of starch decreased from 70% with ground corn to 54% with coarsely rolled corn. Small intestine digestibility of starch was not significantly affected by CPS, and the amount of starch digested in the small intestine tended to be greater for rolled than for ground corn. In both experiments, starch total tract digestibility decreased with increased CPS. In conclusion, CPS is an efficient tool to manipulate rumen degradability of cornstarch. In midlactation cows, the decrease in the amount of starch digested in the rumen between grinding and coarse rolling is partly compensated for by an increase in the amount of starch digested in the small intestine with dent genotype, but with semiflint genotype postruminal digestion is not increased and rumen escape starch is not utilized by the animal.     

厌氧折流板反应器ABR分区进水的实验研究

用六格室厌氧折流板反应器（ABR）,在COD=3000~3500 mg/L,HRT=24 h,对1、3、5格室以不同比例6∶3∶1、5∶3∶2进水,考察每个格室的厌氧污泥、pH值、COD、VFA、碱度等指标,与同等负荷的单侧进水ABR处理结果作比较,结果表明在此负荷下,分区进水处理效果优于单侧进水,并且进水比为5∶3∶2优于6∶3∶1。     

氢化物-原子荧光光谱法测定化妆品粉质原料中4种有害重金属

建立了一种测定化妆品粉质原料中Pb,Hg,As和Cd 4种重金属元素的湿式消解-氢化物发生原子荧光光谱法。通过比较湿式消解法和干灰化法的加标回收率,结果显示,湿式消解法更适合4种重金属元素的前处理。在较优的实验条件下,湿式消解-氢化物发生原子荧光光谱法测定Pb,Hg,As和Cd的线性范围分别为0~16.0,0~1.6,0~16.0和0~1.6μg/L,相关系数(R~2)为0.993 5~0.999 7,方法检出限为0.036~0.768μg/L,样品加标回收率为81.0%~93.0%。该方法灵敏度高,精密度和准确度好,满足分析要求。同时利用该方法实际检测了10种化妆品粉质原料。     

Origin and Processing Methods Slightly Affect Allergenic Characteristics of Cashew Nuts (Anacardium occidentale)

The protein content and allergen composition was studied of cashews from 8 different origins (Benin, Brazil, Ghana, India, Ivory Coast, Mozambique, Tanzania, Vietnam), subjected to different in‐shell heat treatments (steamed, fried, drum‐roasted). On 2D electrophoresis, 9 isoforms of Ana o 1, 29 isoforms of Ana o 2 (11 of the acidic subunit, 18 of the basic subunit), and 8 isoforms of the large subunit of Ana o 3 were tentatively identified. Based on 1D and 2D electrophoresis, no difference in allergen content (Ana o 1, 2, 3) was detected between the cashews of different origins (P > 0.5), some small but significant differences were detected in allergen solubility between differently heated cashews. No major differences in N‐ and C‐terminal microheterogeneity of Ana o 3 were detected between cashews of different origins. Between the different heat treatments, no difference was detected in glycation, pepsin digestibility, or IgE binding of the cashew proteins.     

厌氧处理宣纸檀皮蒸煮黑液

采用酸化预处理和厌氧折流工艺对宣纸生产中产生的高浓度檀皮蒸煮黑液进行处理研究.结果表明:预处理主要是进行水解和酸化,改善废水水质;厌氧折流反应器(ABR)是处理的主要单元,当进水COD浓度为7 250～8 500mg/L,ABR的水力停留时间为24h,容积负荷为9.2kg COD/(m3@d)时,ABR反应器对COD的去除率超过80%;两相厌氧处理可作为好氧处理的预处理段.     

Immune-enhancing effects of β-lactoglobulin glycated with lactose following in vitro digestion on cyclophosphamide-induced immunosuppressed mice

β-Lactoglobulin (β-LG) is a major milk protein, making up more than 53% of the total whey proteins, and is seen as a valuable ingredient in food processing because of its high essential amino acid content and diverse functional applications. The Maillard reaction can occur during the storage and processing of food and generate various beneficial effects, including anti-allergenicity, antioxidant, and immunomodulatory effects. The addition of an β-LG-lactose conjugate (LGL) produced by the Maillard reaction was shown to have a strong immune-enhancing effect, increasing both nitric oxide generation and cytokine expression through activation of RAW 264.7 cells, even after in vitro digestion. Furthermore, daily LGL administration resulted in the upregulation of several immune markers in a cyclophosphamide-induced immunosuppressive mouse model, indicating that this treatment stimulates multiple immune cells, including macrophages, natural killer cells, and lymphocytes, enhancing the proliferation and activation of both the innate and adaptive immune responses. Taken together, these findings indicate that consuming LGL on a regular basis can improve immunity by increasing the natural production of various immune cells.     

微波消解光度法测定奶粉中的磷

样品预处理在分析测定过程中具有十分重要的作用。本研究探讨了一种新兴的样品预处理方法--微波消解法在奶粉分析中的应用。考察了微波消解时溶剂的用量、消解液体积、消解时间、功率和压力对消解效果的影响,选择了微波消解的最佳工作参数。与传统方法相比,该方法具有省时、省酸,操作简单,减少沾污,改善工作环境等优点,是一种有效的实用方法。     

分级醇沉香菇多糖益生活性研究

目的 比较分级醇沉香菇多糖的益生活性差异。方法 采用20%、50%和80%乙醇对香菇多糖进行分级醇沉,并研究分级醇沉香菇多糖对植物乳杆菌的增殖作用和体外耐受模拟胃肠液性能。结果 在发酵48 h时,以80%醇沉香菇多糖为碳源时,植物乳杆菌活菌数可达到9.62 log CFU/mL; 50%醇沉(9.21 log CFU/mL)、20%醇沉(9.07 log CFU/mL)和菊粉组(8.67 log CFU/mL)无显著差异,但都显著高于葡萄糖组的活菌数(8.35 log CFU/mL,P<0.05)。发酵液pH表明,在发酵48 h时, 80%醇沉香菇多糖组的pH降低至3.23,显著低于其他组(P<0.05)。体外模拟胃肠液结果表明,以80%醇沉香菇多糖为碳源培养120 min时,植物乳杆菌在模拟胃液和肠液中的存活率分别为63.37%和96.37%,显著高于葡萄糖组和菊粉组(P<0.05)。结论 以80%醇沉香菇多糖为碳源可以促进植物乳杆菌的增殖,并提高植物乳杆菌在模拟胃肠液环境中的存活率,具有一定的益生元活性。     

Effects of simulated digestion in vitro on cell wall polysaccharides from kiwifruit (Actinidia spp.)

Cell wall polysaccharides are resistant to digestion and absorption in the human small intestine and are considered to be delivered to the colon in a chemically unaltered state. In this paper, pulp from green and gold kiwifruit was subjected to in vitro upper-intestinal tract digestion and the chemical and physical changes to cell wall polysaccharides (dietary fibre) were investigated. Yields of insoluble fibre decreased slightly with simulated digestion while soluble fibre yields increased. Constituent sugar and glycosyl linkage analysis of the soluble and insoluble fibre fractions revealed that the chemical composition and structure of the non-starch polysaccharides remained largely unchanged. However, the degree of methylesterification of galacturonic acid residues present in the pectin-rich soluble fibre fractions of both fruit decreased with treatment; size-exclusion chromatography detected changes in the molecular weight profiles of these fractions. These changes may affect the physicochemical properties and fermentability of kiwifruit dietary fibre in the large intestine.     

双光道原子荧光光谱法测定小麦粉中的砷和汞总量

应用高压消解-双光道原子荧光光谱法同时测定小麦粉中总砷和总汞,研究了消解液、酸介质及其浓度、预还原掩蔽剂、预还原反应时间以及所可能存在的金属离子对检测结果的影响。对消解方法,消解条件和实验参数进行了改进,并指出了关键点控制要素和实际工作中的注意事项。在理想实验条件下,能够较好地解决金属离子之间的相互作用和信号干扰问题,对砷和汞检测的线性范围分别为4.0～200.0 μg/L和1.0～100.0 μg/L,相关系数分别为0.9997和0.9999,加标回收率分别为95.06%～99.57%和95.57%～100.10%,RSD分别≤3.64%和≤4.51%,测量结果准确,具有一定的研究和应用价值。