Structure and rheological properties of extruded whey protein isolate: Impact of inulin

Impacts of inulin addition (0, 5, 10, 15 %) on structure, functional and rheological properties of whey protein isolate (WPI) after extrusion pretreatment (E-WPI) were investigated. The results proved that after adding 15 % inulin, water holding capacity of gels, emulsifying activity, emulsion stability, foaming ability and foaming stability of E-WPI were the best and increased by 24.38 %, 7.43 %, 12.35 %, 162.97 % and 41.31 %, compared with those of unextruded WPI, respectively. Rheology analysis showed that apparent viscosity and consistency index of all the samples after inulin addition were enhanced and exhibited pseudoplastic fluids. FTIR spectroscopy indicated that E-WPI/WPI and inulin was linked together due to hydrogen bonds and addition of inulin increased the proportion of their β-turn structure. These findings demonstrated that the addition of inulin in combination with extrusion pretreatment could jointly improve the functional properties of WPI. Therefore, E-WPI with the addition of inulin shows potential commercial applications in the production of novel food foaming agents and emulsifiers.

Characterization of major volatile compounds in whey spirits produced by different distillation stages of fermented lactose-supplemented whey

This research aimed to advance the understanding of acceptable sensory qualities of potable whey-based spirit from nonsupplemented, mid-supplemented, and high-supplemented whey samples by analyzing major volatile compounds during different stages of distillation (head, heart, and tail). The results demonstrated that commercial Saccharomyces cerevisiae strain in lactase-hydrolyzed whey showed rapid and complete sugar hydrolysis and efficient ethanol production in 24, 30, and 36 h on average, producing up to 29.5, 42.1, and 56.4 g/L of ethanol, respectively. The variations in titratable acidity, specific gravity, pH value, residual protein, sugar content, and alcohol yield were investigated during the fermentation. The total amount of volatile compound concentrations significantly decreased from the head (2,087-2,549 mg/L) to the tail whey spirits (890-1,407 mg/L). In the whey spirit, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, acetaldehyde, and ethyl acetate were the most prevalent ruling compounds, accounting for the largest proportion of total volatile compounds. The volatile compounds detected were far below the acceptable legal limit. The results suggest that high sensory qualities of potable whey-based spirits can be produced by fermentation of lactose-supplemented whey with S. cerevisiae cells.

Investigation of the consequences of ultrasound on the physicochemical, emulsification, and gelatinization characteristics of citric acid-treated whey protein isolate

The effect of ultrasound (US) pretreatment (0, 200, 400, 600, and 800 W) on the physicochemical, emulsification, and gelatinization characteristics of citric acid (CA)-treated whey protein isolate (WPI) was investigated. Size exclusion chromatography demonstrated that when compared with untreated WPI, US pretreatment promoted production of more molecular polymers in the CA-treated WPI. There was a reduction in particle size of CA-treated WPI with the increase of US power (0-800 W), whereas its free sulfhydryl content, surface hydrophobicity, and intrinsic fluorescence strength increased. Furthermore, compared with untreated WPI, emulsifying ability index and emulsifying stability index of CA-treated WPI were increased by 14.04% and 10.10%, respectively, at 800 W. Accordingly, US pretreatment promoted the gel formation of CA-treated WPI, and its gel hardness was increased by 28.0% with US power ranging from 0 to 800 W. Therefore, US and CA treatment can be considered as an effective way to improve the emulsifying and gelatinization characteristics of WPI.

Effects of alendronate on the peri-implant bone in rats

OBJECTIVES

The purpose of this study was to determine the effects of alendronate on the peri-implant bone in rat maxillae with the aid of micro-computed tomographic, histologic, and biochemical analyses.

MATERIALS AND METHODS

Thirty-six male Sprague-Dawley rats were used. After extraction of the maxillary first molars, each rat was given periodic subcutaneous injections of either alendronate (alendronate group) or saline (control group). Customized implants were placed bilaterally 4 weeks after these injections. The rats were sacrificed at either 4, 8, or 12 weeks after implantation (4-, 8-, and 12-week groups, respectively; n = 6 rats per group). Microcomputed tomographic and histologic analyses were conducted for all rats. Biochemical analyses were performed at four time points for the 12-week groups.

RESULTS

There were no significant differences between the groups on microcomputed tomographic and histologic analyses. All of the measured biochemical parameters tended to decrease over time, with significant differences among some time points within each group. The serum osteocalcin level was significantly lower in the 12-week alendronate group than in the control group (P < 0.05).

CONCLUSIONS

Three approaches were utilized in evaluating the effects of alendronate. It appears serum osteocalcin levels may serve as an adjuvant marker for this purpose, although further studies are required to confirm this.

Development and Use of Field Application Vectors To Express Nonadaptive Foreign Genes in Competitive Environments

Many potential applications of genetically engineered microorganisms in environmental and agricultural biotechnology involve introducing genetic capabilities into nonsterile competitive environments in which they provide no advantage to the host. Field application vectors have been designed for the purpose of creating a temporary niche for the host in such environments. This technique involves the addition to the target environment of a selective substrate readily utilizable by the host microorganism but unavailable to most indigenous species. Thirteen nonionic and anionic detergents, representing a wide range of structural complexities and molecular weights, were screened as potential selective substrates. Competition experiments in soil, using Warburg respirometry, indicated that isolates from six different detergent enrichment cultures were more active on their corresponding detergents than the indigenous microorganisms. Detergents of intermediate structural complexities and molecular weights were most effective for use as selective substrates. A field application vector that utilizes 1.0% Igepal CO-720 (detergent) as the selective substrate and Pseudomonas paucimobilis 1IGP4 as the host was tested for its ability to increase the presence of nonadaptive tetracycline resistance marker genes in soil. In soil amended with the selective substrate, strain 1IGP4 plate counts increased by three orders of magnitude and tetracycline-resistant transformant (pRK293) counts increased from 1.8 × 10 6 /g of soil to 4.3 × 10 8 /g in 2 days. Inoculation in the absence of substrate amendment or amendment with a nonselective substrate did not result in growth of strain 1IGP4. These results demonstrate the effectiveness of field application vectors for increasing the concentration of nonadaptive genes in competitive environments.

Effect of potassium infusion on the human conduction system

His bundle electrograms were recorded in 12 patients before and after the intravenous administration of 5 mEq of potassium. Antegrade and retrograde refractory periods were determined with the extrastimulus technique. The AH interval was 84 +/- 7 msec before and 89 +/- 7 msec after potassium (P < 0.05). The AH interval at an atrial pacing rate of 140/minute was 129 +/- 13 msec before and 143 +/- 16 msec after potassium (P < 0.02). The effective refractory period of the atrium was 264 +/- 9 msec before and 280 +/- 9 msec after potassium (P < 0.001). Thus small amounts of potassium delay conduction at the atrial and AV nodal level.

Electrophysiologic properties of nitroprusside in man

The effects of nitroprusside on His bundle electrograms, when given intravenously for 10 minutes, were studied in 14 patients with heart disease. Recordings were made at varied heart rates using atrial and ventricular pacing. Nitroprusside significantly reduced the AH interval, but it had no effect on the HV interval. Functional and effective refractory periods were measured by the extrastimulus technique. The functional refractory period of the AV node as well as the effective refractory period of the ventriculoatrial conduction system significantly decreased after nitroprusside infusion. This improvement in conduction can probably be explained by the systemic hypotension produced by nitroprusside, which reflexly will increase sympathetic drive to the heart and decrease vagal tone.

His bundle electrogram in patients with acute myocardial infarction

Thirty-seven patients with acute myocardial infarction complicated by atrioventricular or bundle branch block, or a combination of both, has His bundle electrogram studies performed during their stay in the coronary care unit. The acute mortality of the 14 patients with a complicating bundle branch was 50%. Pump failure was the main cause of death. Three patients in this group had a prolonged H-V interval and one patient had a split blundle of His. The presence or absence of a prolonged H-V interval did not affect mortality in this group of patients. The acute mortality of the 16 patients with an inferior wall myocardial infarction was 6%. The H-V interval was normal in all but one of these patients. The atrioventricular block was caused by a proximal block in all cases. The acute mortality of the seven patients with an anterior wall myocardial infarction was 29%. The H-V interval was prolonged in two of seven patients. Pump failure was the acute cause of the deaths. The presence or absence of a prolonged H-V interval did not affect mortality in this group of patients.

Decline of serum phosphorus in acute myocardial infarction

Levels of serum calcium, phosphorus, magnesium, SGOT, CPK, and LDH were measured in 61 patients admitted to a coronary care unit. In 34 the ECG and enzymes confirmed an acute myocardial infarction, whereas the remaining 27 did not have an acute myocardial infarction. The serum phosphorus declined significantly in those with the acute infarction compared to the control group. The fall was most marked in the third and fourth postinfarction day, and by the fifth day had returned to baseline values. The serum calcium and magnesium did not change significantly over the 5 days. Thus the fall in the serum phosphorus serves as a sensitive indicator of acute myocardial infarction.

Pericardial effusion as an early complication of acute myocardial infarction

Two days after an acute myocardial infarction, a patient developed pleuropericarditis. A negative lung scan and echocardiographic evidence of pericardial effusion were instrumental in making the diagnosis. Steroid therapy led to a dramatic resolution of the signs and symptoms. Pericardial effusion is usually a late complication of myocardial infarction (Dressler's syndrome), but the increasing use of echocardiography may demonstrate that it occurs early in the course.

Electrophysiologic properties of coffee in man

There is no information on the effects of coffee on the human conduction system. His bundle electrograms were obtained in 12 patients before and 20 minutes after the ingestion of coffee containing 150 mg caffeine. Antegrade and retrograde refractory periods were obtained with the extrastimulus method. The effective and functional refractory period of the atrioventricular node decreased after coffee ingestion. This improvement in conduction is probably mediated by a release of catecholamines.

Hemodynamic effects of phentolamine in valvular abnormalities

Seven patients with mitral insufficiency and seven patients with aortic insufficiency were studied by right and left heart catheterization. Hemodynamic observations were made during a control period and during the infusion of phentolamine. Significant declines in the pulmonary artery mean pressure, left ventricular end diastolic pressure, peripheral resistance, and arteriovenous oxygen difference were seen in both groups. The cardiac index increased significantly in the two groups. Phentolamine therapy produced favorable hemodynamic effects because of its vasodilating action as well as its positive inotropic effects.

Premature hair graying: a probable coronary risk factor

Hypertension, diabetes mellitus, hypercholesterolemia, and smoking are known coronary risk factors. It has been our impression that premature graying of the hair also predisposes individuals to myocardial infarctions. To test this hypothesis, we evaluated all of the patients under the age of 50 who were admitted to the coronary care unit between 1974 and 1976 with a proven diagnosis of a myocardial infarction. There were 50 patients. Thirty-eight did not have premature graying. Twelve of the male patients (24%) had virtual total graying of the hair which made them appear older than their stated age. The graying in these patients started on the average at 29 years. Five of these patients state that other family members had premature hair graying. The incidence of diabetes, hypertension, and smoking was similar in those with and without premature hair graying. This preliminary study suggests that premature graying of the hair is associated with premature cardiovascular disease. It should probably be regarded as a coronary risk factor and used to identify patients at increased risk.

Hemodynamic effects of morphine in cardiac disease

The hemodynamic effects of intravenous morphine were documented by right heart catheterization in six patients with an acute uncomplicated transmural myocardial infarction one to three days after the onset of symptoms. Intracardiac pressures, brachial artery pressure, and cardiac output were determined before and 15 minutes after the termination of the morphine infusion. Five milligrams morphine was given intravenously over a 10-minute period. The brachial artery pressure fell from a mean of 78 to a mean of 73 mm Hg (NS). As a result or morphine administration, the average cardiac index decreased from 2.68 to 2.31 liters/min-m2 (P is less than 0.05), and the stroke index decreased from 27 to 22 ml/beat-m2 (P is less than 0.05). Only small changes were observed in the intracardiac pressures.

The effect of phentolamine on intra-Hisian conduction

A His bundle electrogram was obtained in a 70 year old male with syncopal episodes. A split bundle of His deflection was recorded. After the intravenous administration of phentolamine, a marked shortening of the H-H' interval was observed. This signifies an improvement in conduction at the bundle of His level.