Comparative content of some phytochemicals in Spanish apples,peaches and pears

Dietary fibre, total polyphenols and phenolic acids in Spanish apples, peaches and pears were analysed and compared with their total radical‐trapping antioxidative potential (TRAP). There were no significant differences in the content of dietary fibre among the studied fruits. The content of total polyphenols was 2.4 ± 0.4, 2.1 ± 0.3 and 6.9 ± 0.7 g kg^?1 in peeled fruits and 4.7 ± 0.4, 4.5 ± 0.4 and 11.1 ± 1.2 g kg^?1 in their peels for peaches, pears and apples respectively. The contents of dietary fibre, total polyphenols, caffeic, p‐coumaric and ferulic acids and the TRAP values were significantly (P < 0.05) higher in peels than in peeled fruits. The contents of all studied compounds and the TRAP values were significantly higher in peeled apples and their peel than in peaches and pears. We observed a strong correlation between the contents of total polyphenols and phenolic acids and the total radical‐trapping antioxidative potential in all three fruits. The relatively high content of dietary fibre, the highest contents of total polyphenols, caffeic, p‐coumaric and ferulic acids and the highest value of TRAP make apples preferable among the studied fruits for dietary prevention of atherosclerosis and other diseases. © 2002 Society of Chemical Industry     

Kinetic Studies During Enzyme Hydrolysis of Potato and Cassava Starches

The hydrolysis of raw potato and cassava starches by bacterial α-amylase depends on the time of action, temperature and on the specific starch involved. The molecular weight of the trade α-amylase (Termamyl 60L), determined by SDS-PAGE, was found to be 55–65 kDa. The properties of α-amylase such as kinetic parameters, inhibition, stability, and thermostability were studied. The constants K_m and maximum reaction rate V_max for α-amylase were fitted to Michaelis-Menten models with these two starches. Differences in response of potato and cassava starches to hydrolysis by Termamyl 60L can explain differences found in K_m and V_max values and inhibition properties.     

Effect of hesperidin and naringin on the plasma lipid profile and plasma antioxidant activity in rats fed a cholesterol‐containing diet

The objective of this study was to compare the influence of hesperidin and naringin, the main flavonones of orange and grapefruit, on plasma lipid profile and antioxidant activity in rats fed a cholesterol‐containing diet. Sixty male Wistar rats were randomly divided into six groups of 10, named Control, Hesperidin, Naringin, Chol, Chol/Hesperidin and Chol/Naringin. The Control group was fed a basal diet (BD) and 1–2 mL of distilled water. To the BD of the other five groups were added 0.1–0.2 mg of hesperidin dissolved in 1–2 mL of distilled water (Hesperidin group), 0.46–0.92 mg of naringin in 1–2 mL of water (Naringin group), 1% of non‐oxidised cholesterol (NOC) and 1–2 mL of water (Chol), 1% of NOC and 0.1–0.2 mg of hesperidin in 1–2 mL of water (Chol/Hesperidin), 1% of NOC and 0.46–0.92 mg of naringin in 1–2 mL of water (Chol/Naringin). After 30 days of the experiment it was found that the diets supplemented with hesperidin and naringin increased the plasma antioxidant activity. In conclusion, diets supplemented with hesperidin and naringin significantly hindered the increase in plasma lipid levels caused by cholesterol feeding. Hesperidin and naringin, bioactive compounds of citrus fruits, are powerful plasma lipid lowering and plasma antioxidant activity increasing flavonones. Copyright © 2007 Society of Chemical Industry     

Characterization of blond and Star Ruby (red) Jaffa grapefruits using antioxidant and electrophoretic methods

Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R² from 0.8456 to 0.9711). In both the cultivars studied, thirty‐two electrophoretic bands were detected [sodium dodecyl‐polyacrylamide gel eletrophoresis (SDS‐PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits.     

Renal artery stenosis and chronic renal failure in NIDDM

The NIDDM patient, willingly with high blood pressure and atheroma, has frequently an abnormal renal function. Must a renal artery stenosis (RAS) be searched as a determining or favorising cause? We have searched RAS by color duplex scan, in 60 consecutive NIDDM patients with altered renal function (creatinine clearance < or = 60 mL/min). Metabolic blood pressure (ABPM), cardiovascular and renal investigations have been realised. The population was composed of 22F/38M with middle age: 70.7 +/- 6.2 yrs, diabetic duration: 11.6 +/- 8 yrs, the plasma creatinine was: 161 +/- 78 mumol/L and clearance: 40 +/- 13 mL/min. Thirty eight had albuminuria, 28 had plasma creatinine > or = 150 mumol/L. All patients had high blood pressure. Significative RAS (> or = 70%) was detected in 15 patients (25%) by color duplex scan and proved with arteriography (n = 10) or angio NMR (n = 5). Twelve (80%) had unilateral stenosis (4 thrombosis), 3 (20%) bilateral stenosis. Renal US lead the diagnosis in 10 patients (66%): unilateral or bilateral hypotrophy. Those 15 patients had these following characteristics: 4F/11M (sex R : 0.36), middle age: 70.8 +/- 7.2 yrs, diabetic duration: 14.3 +/- 7.5 yrs, HbA1c was at 8.4 +/- 2%, 8 (53%) patients require insuline and 5 have retinopathy, plasma creatinine was at 169 +/- 6 mumol/L; 32% of patients with plasma creatinine > or = 150 mumol/L had RAS (n = 9/60%), creatinine clearance was at 38 +/- 12 mL/min (7/47% < or = 30 mL/min), 9 (60%) had macroalbuminuria and 5 (33%) microalbuminuria. All hypertensive patients were treated (mean SBP: 148 +/- 16, mean DBP: 82 +/- 7 mmHg) and had 62 +/- 28% SBP escape and 33 +/- 19% DBP escape. Ten had severe hypertension (at least 3 hypotensive drugs), 12 received CEI; 8 (53%) were smokers; 14 (93%) had one or more macroangiopathies (10/66% coronary heart diseases, 7/46% lower limbs arteritis, 6/40% carotid atheroma); 13 of these macroangiopathies are severe. In conclusion, renal failure (especially evolutive and/or treated with CEI) in NIDDM must call up a RAS (25%) specially in elderly males with a long diabetes duration, severe hypertension and macroangiopathies. This patient profile must lead to a color duplex scan to confirm the diagnosis already suspected by the renal echography.     

The Effects of Enzyme Hydrolysis on the Properties of Potato,Cassava and Amaranth Starches

X-ray diffraction method and differential scanning calorimetry were used to study the effects of enzyme hydrolysis on physico-chemical properties of potato, cassava and amaranth starches. Various hydrolysis procedures and different sources of enzymes were employed. The highest percentage of hydrolysis was obtained using the bacterial thermostable α-amylase following by the saccharification with amyloglucosidase. Enzyme treatment showed decrease in the degree of crystallinity of all hydrolyzed starch samples of A-type crystals. B-and C-types were weakened upon enzymatic hydrolysis at 60°C and completely dissappeared at 100°C. The gelatinization endotherm decreased for samples with low degree of crystallization and disappeared in samples with amorphous stage.     

Efficient Memory Management for Cellular Monte Carlo Algorithm

Data compression techniques aimed to the reduction of the memory usage of the Cellular Monte Carlo (CMC) approach are presented in this work. Two approaches have been investigated and implemented, resulting in memory savings of 25 and 50% of computer random access memory (RAM). The loss of precision due to the proposed techniques is measured, and its consequences are studied. The validity and accuracy of the results obtained with compression is verified and robustness is tested on various semiconductor materials. Some applications of the proposed approach are discussed as well.     

Error Analysis of the Poisson P3M Force Field Scheme for Particle-Based Simulations of Biological Systems

The ability to accurately simulate electrolyte solutions is a strong requirement for the modeling of charge transport in ion channels. In this work, a Particle-Particle–Particle-Mesh (P³M) algorithm is used to model the electrostatic interactions governing the physics of electrolyte solutions. The goal of this study is to define the parameters relevant for this force field, and their respective influence on the accuracy of the simulation. Simulations have been performed for extended ranges of these parameters and the results are compared to theoretical models. Finally, the trade-offs between optimal algorithmic efficiency and accuracy are analyzed.