Sara Bastida

Characteristics and Nutritional and Cardiovascular-Health Properties of Seaweeds

While marine algae have traditionally formed part of the Oriental diet, their major use in Western countries has been in the phytocolloid industry. Only a few coastal communities outside Asia have customarily used seaweeds as components of special dishes. Of late, however, seaweeds have gained importance as foodstuffs in Western countries and most recently as components of functional foods because of their high dietary fiber, mineral, vitamin, and phytochemical content, low energy levels, and high concentrations of certain polyunsaturated fatty acids. The present paper reviews the available data for some of the components of the major edible algae and studies several factors that can affect their physiochemical properties (e.g., hydration, water and oil-holding capacity, fermentability, binding capacity, etc.) and, in turn, their nutritional importance. The effects of marine alga consumption on growth and body weight, mineral availability, lipid metabolism, blood pressure, and antioxidant properties are reviewed, together with preliminary data on the effects of some functional foods containing seaweeds on lipid metabolism and gene expression of enzymes engaged in antioxidant protection. This review concludes with some remarks regarding the danger of the improper use of seaweeds in herbal medications. In addition, as the properties of algae are highly dependent on their individual composition, any generalization regarding these properties may be considered misleading and scientifically inappropriate.

Thermal oxidation of olive oil, sunflower oil and a mix of both oils during forty discontinuous domestic fryings of different foods

Changes in sunflower oil (SO), olive oil (OO) of 0.4º acidity value and a mixture (1:1) of both oils (MO) were studied during forty domestic discontinuous deep-fat frying of various foodstuffs, mostly frozen foods. The replenishment of the oil in the fryer with fresh oil was performed after every ten uses to maintain the oil volume in the fryer. Alteration of oils was evaluated by measuring polar content (PC) and compounds related to thermoxidative and hydrolytic changes. PC increased with different rates in the three oils, thus after twenty fryings, PC was 25.3 g/100 g oil for SO, 22.4 g/100 g oil forMOand 19.7 g/100 g oil for OO. At the fortieth frying, the three oils surpassed the critical level for PC of 25 g/100 g oil, but SO andMOwere abused oils with a PC value = 30 g/100 g oil. Oxidized triacylglycerols (OTG), triacylglycerol dimers (TD) and triacylglycerol polymers (TP) increased after forty fryings 6.1, 34.5 and 260 times, respectively, in SO; 7.8, 50.9 and 115.8 times, respectively, in MO and 19.5, 70 and 149 times, respectively, in OO. The TP+TD/OTG ratio was used to assess the more predominant alteration through frying in the three oils. This ratio increased after forty fryings more in SO followed by MO, and then by OO, showing that oils rich in linoleic acid became more polymerized in frying than those rich in oleic acid. According to PC and the thermoxidative changes, MO behaved as a mix of OO and SO. Data indicated that during the first twenty fryings, olive oil of 0.4 º acidity value and the oil mix performed more satisfactorily than sunflower oil in repeated fryings of frozen foods, however, differences in frying oil behavior decreased during the last twenty fryings.

Nutritional and antioxidant properties of different brown and red Spanish edible seaweeds.

This article reports a study of the nutritional composition, total dietary fiber (TDF), mineral contents, fatty acid and amino acid profiles, polyphenolic concentration and antioxidant activity of three Spanish seaweeds: two brown seaweeds (Himanthalia elongata and Undaria pinnatifida) and one red (Porphyra umbilicalis). TDF and ash were the most abundant components in the brown seaweeds, while TDF and protein were the main components in the red one. In all seaweeds, the lipid contents were very low but the polyunsaturated fatty acid contents were high. Although the red seaweed contained significantly (p < 0.05) more protein content than the brown ones, all three contained all the essential amino acids at levels comparable to FAO/WHO requirements. The brown seaweeds contained significantly more minerals than the red one; they are a rich source of K, Na, Ca and Mg and present a beneficial Na/K ratio. Himanthalia elongata displayed remarkably high polyphenolic content, endowing it with appreciable antioxidant activity. These seaweeds offer considerable potential as functional food ingredients due to components like dietary fiber, minerals and trace elements, protein and lipids, which produce many different kinds of biological activities, and also to their high antioxidant capacity.

Maternal diets with low healthy eating index or mediterranean diet adherence scores are associated with high cord-blood insulin levels and insulin resistance markers at birth

Background/Objectives:Few studies have used healthy eating index (HEI) and mediterranean diet adherence (MDA) scores to evaluate the diet quality during pregnancy. To determine the relationship between first trimester diet quality and insulin sensitivity/resistance biomarkers at birth.Subjects/Methods:Cord-blood insulin sensitivity/resistance biomarkers of the offspring of 35 women whose diets were ‘adequate’ or ‘inadequate’ according to their HEI score (>70 or ⩽70, respectively) and their 13-point MDA score (⩾7 or <7, respectively).Results:Low HEI-score diets contained less (g/1000 kcal) carbohydrates (CHO; P=0.027) and fibre (P=0.011), and more fats (P<0.001) and cholesterol (P<0.001), and contributed (percentage contribution to total energy (%En)) fewer CHO (P=0.005), more fats (P=<0.001) and saturated fatty acid (SFA; P=0.002) than their high HEI-score counterparts. Low MDA-score diets contained less (g/1000 kcal) fibre (P<0.001) and more cholesterol (P=0.05), had lower polyunsaturated fatty acids+monounsaturated fatty acid/SFA (PUFA+MUFA/SFA; P=0.05) and higher SFA/CHO (P=0.021) and ω-6/ω-3 PUFA ratios (P=0.044) than their respective counterparts. Women consuming the low HEI- or low MDA-score diets had low-fasting glycaemia (P=0.016 or P=0.025, respectively) but delivered infants with high insulinaemia (P=0.048 or P=0.017, respectively), homeostatic model assessment for insulin resistance (HOMA-IR; P=0.031 or P=0.049, respectively) and glycaemia (P=0.018 or P=0.048, respectively). The relative risk (RR) of high-neonatal glycaemia and insulinaemia were 7.6 (P=0.008) and 6.7 (P=0.017) for low vs high HEI-score groups. High HOMA-IR and high glucose RR were, respectively, 3.4 (P=0.043) and 3.9 (P=0.016) in neonates from the <7 MDA- vs ⩾7 MDA-score group. These RRs were not affected by potential confounders.Conclusion:Maternal diets with low HEI- or MDA-scores during the first trimester of pregnancy negatively affect insulin resistance markers at birth.

Effects of hydroxytyrosol-enriched sunflower oil consumption on CVD risk factors

Inclusion of biophenols in traditional foods transforms them into functional foods that may help to decrease CVD risk. The aim of the present study was to determine whether the consumption of hydroxytyrosol-enriched sunflower oil (HSO) improves certain CVD biomarker values. A total of twenty-two healthy volunteers participated in a cross-over study involving two 3-week periods, separated by a 2-week washout period, in which volunteers consumed 800-1275 μg/d [corrected] of either HSO (45-50 mg/d of hydroxytyrosol) or non-enriched (control) sunflower oil. Total cholesterol, LDL-cholesterol, HDL-cholesterol, arylesterase activity, oxidised LDL and soluble vascular cell adhesion molecule (sVCAM-1) levels were measured in the plasma obtained at the beginning and at the end of each treatment period. The HSO group displayed a significantly higher level (P < 0·01) of arylesterase activity and significantly lower levels of oxidised LDL and sVCAM-1 (both P < 0·05) than the control group. These results suggest that HSO may help prevent CVD.

Effect of walnut-enriched meat on the relationship between VCAM, ICAM, and LTB4 levels and PON-1 activity in ApoA4 360 and PON-1 allele carriers at increased cardiovascular risk

Background/objective:Cardiovascular risk depends largely on paraoxonase (PON-1) and apolipoprotein A4 (APOA4) gene polymorphisms. To compare the effects of consumption of walnut-enriched meat versus low-fat meat (LM) on selected soluble adhesion molecules and leukotrienes (LTB4).Subjects/Methods:In all 22 subjects at increased cardiovascular risk were taken. It is a non-blinded, cross-over, placebo-controlled study. Two 5-week experimental periods separated by 4–6 week wash-out interval. Participants consumed walnut-enriched meat during one period and LM during the other. Diet characteristics, HDLc, Apo A1, paraoxonase, sVCAM-1, sICAM-1 and LTB4 were analysed. PON-1 55, PON-1 192 and APOA4 360 polymorphism effects were also assessed.Results:Individuals consuming walnut-enriched meat displayed higher paraoxonase activity (P<0.001), lower levels of sICAM and aVCAM (P=0.046, P=0.012, respectively) and leukotriene B4 (P=0.044), and lower paraoxonase-1/HDLc and paraoxonase-1/Apo A1 ratios (both, P<0.001) than those consuming LM. Paraoxonase levels correlated negatively with those of sICAM (r=−0.471, P<0.01). Significant decreases (at least P<0.05) were observed in sICAM concentrations in PON-1 55LM+MM, PON-1 QQ192 and APOA4-2 carriers while decreases in sVCAM in QR+RR and APOA4-1 carriers were observed. Paraoxonase-1/HDLc and paraoxonase-1/Apo A1 ratios were significantly influenced by paraoxonase polymorphisms.Conclusions:Walnut-enriched meat appears as a functional meat as consumed in the framework of a mix diet lowered the concentration of some selected inflammatory chemoattractant biomarkers. This effect was largely influenced by PON-1 and Apo A4-360 polymorphisms.

A Nori but not a Konbu, dietary supplement decreases the cholesterolaemia, liver fat infiltration and mineral bioavailability in hypercholesterolaemic growing Wistar rats

The nutritional consequences of algae consumption in young populations consuming hypercholesterolaemic diets have hardly been investigated. This study tests the effect of algae supplementation of cholesterol-enriched balanced diets on growth, dietary efficiency ratio, mineral intake and absorption, organ weight and structure and cholesterolaemia in growing Wistar rats. Three groups of ten rats each were fed for 3 weeks with experimental diets containing 93 % casein-soyabean oil base with 2.4 % cholesterol-raising agent and 7 % supplement. The control group received cellulose (35 %), group 2 consumed Nori (33.8 % fibre) and group 3 consumed Konbu (36.1 % fibre). Food intake and body weight gain were not significantly affected. Algae groups presented significantly higher dietary efficiency ratio values than control rats. Apparent absorption of several minerals appeared significantly affected, mainly in Nori-fed rats, with a significant decrease in the ratio of Zn and Cu intakes and apparent absorption. Nori diet significantly decreased plasma cholesterol. Algae supplement did not significantly affect organ size and structure. Control and Konbu rats showed severe liver fat infiltration, while Nori rats exhibited a significantly lower degree of lipid-like hepatocyte vacuolization but light to moderate leukocyte infiltration. Light to moderate scaling off of the epithelium and moderate submucosa oedema was observed in all groups. Although long-term studies are needed to check the possible extrapolation of these data to human subjects, it can be concluded that a Nori, but not a Konbu, dietary supplement reverses the negative effect of dietary cholesterol intake and also appears to be related to mineral availability in growing subjects.

Column and high-performance size exclusion chromatography applications to the in vivo digestibility study of a thermoxidized and polymerized olive oil.

This study aimed (i) to design an in vivo model to study fat digestibility, and (ii) to apply this design to test the in vivo digestibility of a highly thermoxidized olive oil. True digestibility of unheated olive oil was tested 2, 4, 6, and 7 h after administering 1 g of olive oil/100 g body weight to young adult Wistar rats by means of esophageal probes. Remaining gastrointestinal lumen fat showed an inversely linear relationship (t=−0.9932; P<0.001) with the length of the experiment. A 4-h test was considered adequate because after this period, half of the oil administer still temains in the lumen, making it possible to accurately measure the different nondigested, nonabsorbed themoxidized compounds. In a second experiment, fresh olive oil (3.6 mg polar content/100 mg oil) was heated at 180°C for 50 h in the presence of air; the polar content in this oil rose to 46.0 mg/100 mg oil. After 4 h, the true digestibility coefficient of 50-h heated olive oil did not significantly change, although it tended to decrease (24%) with respect to the unheated oil. Silica gel column chromatography and high-performance size exclusion chromatography were used to quantify nonthermoxidized and thermoxidized products present in the oils and in the gastrointestinal lumen after these test periods. True digestibility of the different thermoxidized compounds from the heated oil was 30–40%, whereas that of thermoxidized compounds from the fresh oil was much higher (∼80%). Nonoxidized triacylglycerol hydrolysis was negatively affected by the presence of large amounts of thermoxidized compounds. The present proposed model seems to be a useful tool for the study of thermoxidized oils. Data also show that thermoxidized compounds from abused olive oil are poorly but actively hydrolyzed and absorbed in vivo.

Male and female cord blood lipoprotein profile differences throughout the term-period.

Age- and gender-related differences in cord serum lipids and lipoproteins were studied in 548 singletons from the Toledo Study, Spain, aged 37.0- < 42.0 wk, with body weight between 2.500 and 3.999 kg and Apgar score of > or = 7 at 1 min and > or = 9 at 5 min. Cord total cholesterol (TC) and LDL-cholesterol were significantly higher in females than in males (1.89 +/- 0.53 vs 1.72 +/- 0.42 mmol/l, p < 0.001; and 0.88 +/- 0.43 vs 0.74 +/- 0.36 mmol/l, p < 0.001, respectively). With the exception of triglycerides which significantly increased through the term period in males and females (both p < 0.01), other serum and lipoprotein lipids remained rather constant between wks 38 and 42 in both sexes. However, all lipids and lipoproteins tended to be higher in 38 wk- than in 37 wk-newborns. Females showed higher HDL-cholesterol levels (p < 0.05) at wk 37, and higher TC and LDL-cholesterol values (both p < 0.05) at wks 39 and 40. TC was more or less equivalently carried by LDL and HDL in both sexes but males transported significantly more cholesterol by VLDL (p < 0.001) and less by LDL (p < 0.05) than females. TC was significantly correlated with LDL-cholesterol (p < 0.001) and HDL-cholesterol (p < 0.001). The different levels of TC and LDL-cholesterol, and the cholesterol distribution for lipoproteins in male and female neonates suggest that gender-related factors might influence lipid levels at term-period.

Effect of seaweed and cholesterol-enriched diets on postprandial lipoproteinaemia in rats.

High postprandial lipaemia increases cardiovascular risk. Algae consumption may affect postprandial lipoproteinaemia. The effects of dietary alga and cholesterol supplementation on postprandial lipaemia and lipoproteinaemia and arylesterase (AE) activity in growing male Wistar rats were tested in the present study. Six groups of ten rats were fed a casein-based diet for 3 weeks. Three of the diets contained 2.4 % cholesterol-raising agent (Chol), while the other three did not (NChol). Seven percentage of the control diets (NChol-C and Chol-C) consisted of a cellulose-wheat starch mix (35:65), while the Nori alga diets (NChol-N and Chol-N) and Konbu diets (NChol-K and Chol-K) contained 7 % of each respective freeze-dried alga. Postprandial plasma was obtained after a 3 h diet withdrawal. Supplementary cholesterol and alga type significantly affected (at least P < 0.05) the cholesterol, TAG, phospholipid and protein contents of the various lipoprotein fractions. AE enzyme activity increased (P < 0.05) in NChol rats given Nori and Konbu diets. NChol-K, but not NChol-N, rats displayed higher (P < 0.05) plasma cholesterol, TAG and phospholipid levels than NChol-C animals. NChol-K rats presented higher TAG, phospholipid, protein and lipoprotein mass values than their NChol-C counterparts. Inclusion of algae in Chol diets decreased (P < 0.001) the postprandial hypertriacylglycerolaemia. The Chol-N diet affected most lipoprotein fraction contents. Chol-N rats had lower postprandial cholesterolaemia and a better lipoprotein profile (fewer LDL and a tendency toward more HDL and fewer cholesterol-enriched VLDL) than Chol-K rats, suggesting that Nori is the alga of choice in dietary treatment of hypercholesterolaemia.