Lourdes Pérez-Olleros

Comparative study of natural carob fibre and psyllium husk in rats. Influence on some aspects of nutritional utilisation and lipidaemia

The effects of the addition of 100 g kg−1 of psyllium husk (PSY), cellulose (CEL) or natural carob fibre (NCF) to a semi-synthetic diet on fat (FD) and nitrogen (NF) digestibility coefficients, metabolic nitrogen utilisation (MNU), net nitrogen utilisation (NNU) and total serum cholesterol and triglyceride levels, were studied in male ‘Wistar’ rats. No significant differences were observed between the three fibres with respect to the weight increase of the animals or MNU. Significant differences were recorded for the FD of the NCF group (0.91±0.01) compared to the CEL group (0.95±0.01), as well as on ND (0.88±0.00 NCF group, 0.88±0.00 PSY group and 0.95±0.00 CEL group) and NNU. None of these indexes showed differences between the groups PSY and NCF. For the serum cholesterol levels, there were no significant differences between the non-hypercholesterolaemic groups fed PSY, CEL or NCF; in those in which hypercholesterolaemia was induced (cholesterol and bile bovine 8.3 g kg−1), significantly lower values were found in the NCF group (166±17 mg dl−1 ) than in the PSY group (343±61 mg dl −1) and in the CEL group (386±48 mg dl−1). © 1999 Society of Chemical Industry

Lipid composition and palatability of canned sardines. Influence of the canning process and storage in olive oil for five years

Lipid variations of canned sardines in olive oil, both quantitative and in fatty acid composition, have been studied during various stages of the canning process: raw sardines (RS), precooked sardines (PS), just canned sardines (CS) and sardines stored for 6 months (6MS), 12 months (12MS) and 5 years (5YS). The effect of maturation on the palatability of sardines has also been observed by means of triangle tests using a panel of 60 tasters. Our results show a significant loss of SFA in fish during the canning process (C16: 0,273 ± 6 g kg -1 of fat in RS and 169± 11 gkg -1 of fat in CS) and a rise in MUFA (C18:1 207 ± 2 g kg -1 of fat in RS and 506 ± 14 g kg -1 of fat in CS); PUFA showed almost no variation. The maturation and canning processes both yielded similar qualitative modifications. The palatability of the sardines was significantly higher after 6 months of maturation than immediately after canning, and this quality was maintained, for at least 5 years of storage.

Mineral absorption of diets containing natural carob fiber compared to cellulose, pectin and various combinations of these fibers Absorción de minerales de dietas que contienen fibra natural de algarrobas comparada con celulosa, pectina y varias combinaciones de estas fibras

The influence of the consumption of natural carob fiber (NCF), an insoluble hypocholesterolemic fiber, as the unique dietary fiber or combined with cellulose (CEL) or pectin (PEC), on mineral bioavailability was studied. Six groups of rats were fed for 10 days diets containing 10% CEL, NCF, PEC or CEL+NCF, CEL+PEC and NCF+PEC mixtures at 50%. Food intake was lower with PEC than NCF and CEL+NCF, but final body weight was unaffected. Fecal weight showed significant differ ences in the following order: CEL, NCF, CEL+NCF > CEL+PEC, NCF+PEC > PEC. Percentage of calcium absorption was higher with CEL+PEC and NCF+PEC compared with the rest of fibers. Mag nesium absorption was also significantly enhanced in these two groups compared to NCF (p < 0.0004). Iron absorption did not show variations. Zinc apparent absorption was reduced by PEC, but the NCF+PEC mixture counterbalanced this effect. Liver iron was significantly lower with NCF+PEC than CEL, and liver iron concentration was significantly lower with NCF+PEC compared to CEL+PEC. Liver zinc was significantly higher with CEL+NCF than PEC while liver zinc concentrations were slightly higher with the former (p = 0.05 compared to NCF). The results indicate that NCF, compared to CEL and PEC, did not decrease the efficiency of calcium, magnesium and iron absorption in rats, while compared to PEC it increased zinc apparent absorption. Moreover, by combining NCF with PEC calcium and magnesium, absorptions enhanced in comparison with NCF alone, which was prob ably a result of the combination of soluble and insoluble fibers.

In vivo bioavailability of polyphenols from grape by-product extracts, and effect on lipemia of normocholesterolemic Wistar rats: Grape by-product in vivo bioavailability

BACKGROUND The direct use of phenolic extracts from grape by-products can be useful when formulating functional food to improve consumer health. The use of phenolic extracts instead of pure polyphenols as an ingredient is relevant in this context. The present study investigated the bioavailability and absorption of polyphenols from grape by-product extracts and their health effect on cholesterolemia, by adding the extract (GE) to Wistar rats diet (50 g kg-1 ) in vivo. RESULTS GE caused the appearance of (+)-catechin, myricetin and quercetic acid in plasma and liver. (+)-Catechin was the most abundant compound (6 μg mL-1 in plasma and 0.7 μg mg-1 protein in liver), whereas no phenolic compounds were detected in plasma or liver in the control group. Similarly, 3,4-hydroxyphenylacetic, a major product of polyphenol digestion, was detected in the plasma, liver and urine of the GE-group only. GE-group had significantly lower cholesterol level and lower total cholesterol/high-density lipoprotein ratio in plasma. Total bile acid content significantly increased in fecal matter after 24 h administration of the GE-enriched diet. CONCLUSION Grape extract polyphenols are partially bioavailable and showed improvement in lipid metabolism. Thus, the results suggest that GE is promising as a functional ingredient in the prevention of hypercholesterolemia.

Comparative study of two techniques for assessing fat intake in a Mediterranean diet. The influence of culinary oils changes

The diet usually consumed by a community of 18 normolipemic monks was studied. It included olive oil as cooking fat (basal period BP). This diet was modified by substituting olive oil for sunflower oil during a 21-day period (experimental period EP). The precise individual weighing technique was utilised for the determination of intake, and by means of the food composition tables (FCTs) the energy and nutrient of the diet were calculated. By chemical analysis of the duplicate sample (CA) of the cooked dishes the lipid intake was also determined. Total serum cholesterol HDL and LDL cholesterol, serum triglycerides, AI and B-100 apolipoproteins and Lp(a) were also analysed. Similarly the absolute and relative values for SFA, MUFA and PUFA obtained by both techniques were also different and these were maintained when the (PUFA + MUFA)/SFA ratio was calculated by both techniques and in the two periods. The correction of the lipid intake by means of the CA technique did not improve either the correlation between the intake or the plasma lipid concentration or the cholesterolemia prediction (r = 0.83 for FCT and CA).The diet usually consumed by a community of 18 normolipemic monks was studied. It included olive oil as cooking fat (basal period BP). This diet was modified by substituting olive oil for sunflower oil during a 21-day period (experimental period EP). The precise individual weighing technique was utilised for the determination of intake, and by means of the food composition tables (FCTs) the energy and nutrient of the diet were calculated. By chemical analysis of the duplicate sample (CA) of the cooked dishes the lipid intake was also determined. Total serum cholesterol HDL and LDL cholesterol, serum triglycerides, AI and B-100 apolipoproteins and Lp(a) were also analysed. Similarly the absolute and relative values for SFA, MUFA and PUFA obtained by both techniques were also different and these were maintained when the (PUFA + MUFA)/SFA ratio was calculated by both techniques and in the two periods. The correction of the lipid intake by means of the CA technique did not improve either the correlation between the intake or the plasma lipid concentration or the cholesterolemia prediction (r = 0.83 for FCT and CA).