PURIFICATION AND PROPERTIES OF A PHYTASE FROM RYE

Phytase (myo-inositol hexakisphosphate phosphohydrolase) has been purified about 2,000-fold from ungerminated rye with a recovery of 6%. The enzyme behaves as a monomeric protein of a molecular mass of about 67 kDa. OptimalpH for the degradation of phytate has been found at pH 6.0 and 45C. Kinetic parameters for the hydrolysis of Na-phytate are KM300 μM and kcat 358 s^?1 at 35C and pH 6.0. The rye enzyme exhibits a broad affinity for various phosphorylated compounds and hydrolyses phytate in a stepwise manner; the pentakis- and tetrakisphosphate were identified as 1(1,2,3,4,5)P₅ and I(2,3,4,5)P4 Consequently, this enzyme is a 6-phytase (EC 3.1.3.26).     

Natural Occurrence of Undecaenes in Some Fruits and Vegetables

1-(E,Z)-3,5-undecatriene and 1-(E,Z,Z)-3,5,8-undecatetraene were isolated under enzyme inhibition from edible parts of peach, passion fruit, and kiwi; the triene only was found in celery, parsley, mandarine, apple and pear. Capillary gas chromatography, sniffing-capillary gas chromatography, and combined “live”-capillary gas chromatography-mass spectrometry of the concentrated liquid-liquid extracts were used to establish their identity. Owing to their ultra-low odor detection thresholds and the proposed biogenesis, these trace compounds may be “character impacts” in a wide variety of food flavors of plant origin.     

State space modelling and spectral analysis of cointegrated vector processes (evidence from the U.S. and Scandinavian economies)

We provide new evidence on the impact of the U.S. economy on two Scandinavian economies (Finland and Sweden). Initially, we test for the presence of unit roots among the observed input-output processes. Next, Granger causality and cointegra-tion of the system is explicitly tested, to justify the estimated vector-valued state space model. The trend and cyclical components of the endogenous vector are extracted by three alternative decomposition methods. Finally, the content of the cyclical component is analysed by spectral analysis.     

Surveying a subsea lava flow using the Autonomous Benthic Explorer (ABE)

This paper summarizes results from the first science deployment of the Autonomous Benthic Explorer (ABE), conducted on the Juan de Fuca Ridge (46°N, 129°W) at depths between 2200 and 2400 m. Using long baseline acoustic transponders, the ABE descended with precision to a preassigned starting point, then executed dead-reckoned tracklines. It followed the bottom at distances between 7 and 20 m using an acoustic fathometer as a reference sensor. The ABE mapped a new subsea lava flow with a magnetometer, imaged the seafloor with a stereo snapshot video system, and mapped a hydro thermal plume with conductivity and temperature sensors. The ABE completed 7 successful dives and covered over 35 km of tracklines. Detailed power records were logged, which permits extrapolation of the ABE's performance to other missions and higher capacity batteries.     

ON THE APPARENT FRACTAL DIMENSION OF SOUND BURSTS IN ACOUSTIC SIGNATURES OF TWO CRUNCHY FOODS1

The jaggedness of the filtered and compressed acoustic signatures of cheese balls and croutons at various levels of water activity was determined in terms of an apparent fractal (Kolmogorov) dimension. The plot of the mean dimension vs water activity had a characteristic sigmoid shape that could be adequately described by a modified version of the Fermi equation. Regression analysis yielded that the apparent fractal dimension, D_fK, of the cheese balls and croutons when dry was around 1.45 and 1.38, respectively. The inflection point, a_wc, that is, the water activity level where half the drop in D_fK occurred, was a_wc= 0.50 and a_wc= 0.55, respectively. The steepness of the jaggedness versus water activity relationship in terms of the a_w range where about 90% of the drop of jaggedness occurred was 0.27 in the cheese balls and about 0.29 in the croutons.     

快速跟踪非标准刀具

高效金属切削解决方案经常需要使用非标准刀具.利用新的网络化CAD系统,德国WalterDeutschland公司的Walter Titex和Walter Prototyp能大幅度缩短从计划阶段,实施,到交货的周期.现今,生产过程中需要的刀具必须尽早拿到.     

IMPROVING ENZYMATIC REDUCTION of MYO-INOSITOL PHOSPHATES WITH INHIBITORY EFFECTS ON MINERAL ABSORPTION IN BLACK BEANS (PHASEOLUS VULGARIS VAR. PRETO)

Activation of endogenous or addition of exogenous phytases during food processing gives a chance to reduce the phytate content in the final product to a nutritionally acceptable level. Optimal conditions for the endogenous phytases of black beans, this is 60C and pH 6.0, resulted in a 55% reduction in 1P₆ after soaking and cooking. the sum of 1P5 and 1P₅ was reduced by 54%. 1P₆ reduction was most extensive when black beans were soaked at 50C while adding exogenous phytases during the last 2 h of soaking. After soaking and cooking 1P₆ was degraded by 85% and the sum of 1P6 and 1P5 was reduced by 82 % compared to the values in raw beans when adding Escherichia coli phytase. Using rye phytase the values were estimated to be 73% and 70%, thereby a clear accumulation of IP₄ occurred. Thus, a significant improvement in reduction of mnyo-inositol phosphates with adverse effects on mineral bioavailability has been achieved in comparison to the usual household procedure.     

PURIFICATION AND CHARACTERIZATION OF A PHYTASE FROM SPELT

Four soluble phytases were identified in germinating spelt. Although numerous purification strategies were applied, none of the four phytases could be purified to homogeneity. The purest phytase preparation, called D21, contained a phytase (major component) and an acid phosphatase (APH) (minor component). The phytase behaves like a monomeric protein of a molecular mass of about 68 kDa and shows a broad substrate specificity. Optimal pH for degradation of phytate was 6.0 and the optimal temperature 45C. Kinetic parameters for the hydrolysis of Na-phytate were K_M 400 μmoll^?1 and k_cat 368s^?1 at pH 6.0. The spelt phytase D21 degrades phytate stepwise.     

改进加工技术应用于新领域

公路上呼啸而过和卡车上多装有Valeo公司的产品.商用卡车联轴节的生产中大量使用着MAGHassapp立式车床. Valeo成立于1923年,现已成为最大的国际汽车供应商之一.该公司共有61200员工,分布于世界各地,主要从事汽车零部件、集成系统、轿车模具和商用货车的开发与制造业务.     

ENDOGENOUS PHYTATE-DEGRADING ENZYMES ARE RESPONSIBLE FOR PHYTATE REDUCTION WHILE PREPARING BEANS (PHASEOLUS VULGARIS)

The three dry nonprocessed bean varieties contain high amounts of phytate ranging from 9.3 to 15.9 μmol g^-1 dry basis, representing 85 to 89% of total myo-inositol phosphates, while the other myo-inositol phosphates were found only in small or trace amounts. Myo-inositol phosphate concentrations were not affected by soaking in water for 15h at 25C, whereas cooking resulted in a significant reduction in phytate content (16 to 24%) with a concomitant increase in the concentrations of the lower myo-inositol phosphates. The sum of phytate and myo-inositol pentakisphosphate after soaking and cooking represents about 93% of the amount in raw beans. Therefore, preparing of beans has only a limited effect on the content of myo-inositol phosphates with inhibitory effects on mineral absorption. Phytate-degrading enzymes (phytases) were identified as responsible for phytate removal during cooking, since a good correlation between phytase activity and phytate hydrolysis was observed.