Red and brown seaweeds extracts: A source of biologically active compounds.

The biological activities of Porphyra sp., Gracilaria gracilis, Alaria esculenta and Saccharina latissima extracts prepared by enzymatic and ball milling-assisted methods and hot water were evaluated. Enzyme-assisted methods allowed the highest extraction yields. Alcalase-assisted extraction (EAA) was the most effective in the recovery of polyphenolic compounds and Porphyra sp. had the highest content. The efficiency of flavonoids extraction was highly dependent on the used method. Globally, Porphyra sp. and EAA extracts exhibited the highest antioxidant and chelating activities. The highest α-amylase inhibitory activity was determined in HW Porphyra sp. extract while EAA A. esculenta extract had the highest α-glucosidase inhibitory activity. The highest ACE inhibitory activity was obtained in EAA from S. latissima. None of the extracts showed antimicrobial activity against the tested bacteria. The results showed that Porphyra sp. and S. latissima are potentially useful as ingredient in functional foods and nutraceuticals.

Microalgal solutions in the cultivation of rotifers and artemia: scope for the modulation of the fatty acid profile.

The microalgae Aurantiochytrium sp. (AUR), Isochrysis sp. (ISO), and Nannochloropsis sp (NAN) were studied as possible alternative feeds to well established commercial compound feeds for both rotifers (Brachionus plicatilis) and Artemia franciscana. Fatty acid (FA) composition -relative (in % of total FAs) and absolute (in mg/g dw)-was determined in order to assess their potential for providing essential FAs. The FA profiles showed relevant differences between the four feeds (compound feed and the three microalgal species), but less stark than in the feeds themselves. Whereas Isochrysis sp. was relatively rich in DHA and poor in EPA, 18.6 ± 1.7% vs 0.6 ± 0.0%, respectively, Nannochloropsis sp. had the opposite pattern, 0.2 ± 0.3% vs 28.3 ± 0.7%. Aurantiochytrium sp. was rich in DHA (19.1 ± 0.2% corresponding to 89.8 ± 0.2 mg/g dw), but posed difficulties as a feed for both rotifers and artemia, given its low lipid incorporation and, in particular, poor DHA deposition. Rotifers fed the compound feed had the best combination of n3 PUFA levels (22.1 ± 0.1 mg/g dw), DHA contents (13.6 ± 0.4 mg/g dw), and DHA/EPA ratios (~3), being rotifers fed AUR and ISO feeds second best. Hence, these microalgae may deserve to be further explored as potential sources of specific FAs in rotifers and artemia.

The development of a novel functional food: bioactive lipids in yogurts enriched with Aurantiochytrium sp. biomass.

Western diets are poor in healthy n3 polyunsaturated fatty acids, such as docosahexaenoic acid. Since microalga Aurantiochytrium sp. is rich in docosahexaenoic acid, a functional food based on lean yogurt and this microalga was tested. This study entailed characterizing the lipid fraction and determining the fatty acid bioaccessibility. The tested yogurts (control and 2% w/w, Aurantiochytrium sp.) had differences. Docosahexaenoic acid was not detected in the control product, but it was the second most important fatty acid in Aurantiochytrium sp. and Aurantiochytrium yogurt, 29.7 ± 0.4% and 18.7 ± 2.0%, respectively. Based on the fatty acid profile only, an amount of 158.7 g of Aurantiochytrium yogurt in wet weight terms would be required to ensure an appropriate intake of healthy fatty acids. Generally, the fatty acid bioaccessibility was not high, remaining below 60-70% in almost all cases. Considering the docosahexaenoic acid bioaccessibility (44 ± 3%), an amount of 360.7 g of Aurantiochytrium yogurt would be advisable. A reasonable dietary prescription would be a daily consumption of 125 ml of Aurantiochytrium yogurt.

Bioprospection of Isochrysis galbana and its potential as a nutraceutical.

Microalgae have strong potential as novel sources of nutraceuticals, as they contain significant amounts of highly valuable bioactive compounds. This study focuses on the bioprospection of biomass of the microalga Isochrysis galbana and its extracts (aqueous and ethanolic), determining total polyphenols, laminarin, fucoxanthin, coenzyme Q10, and ß-carotene contents, and also assessing several biological activities (antioxidant, cytotoxicity, and hypocholesterolemic). I. galbana exhibited high phenolic content, both in aqueous and ethanolic extracts. The microalgal freeze-dried biomass presented a low laminarin content and higher content of fucoxanthin (6.10 mg per g dw), and relevant ß-carotene and Coenzyme Q10 contents were detected. I. galbana aqueous extracts presented a high antioxidant capacity (approximately 90% inhibition by the ABTS method). Furthermore, I. galbana biomass and ethanolic extract showed significant cytotoxicity against HeLa human cervical cancer cells, with IC50 values of 0.32 and 0.28 mg ml-1 respectively, demonstrating potential for further anticancer studies. The aqueous extract of I. galbana induced a significant decrease of cholesterol absorption through Caco-2 monolayers, modelling the human intestinal barrier, which suggests that it may contribute to decreasing the dietary cholesterol absorption.

Portuguese preschool children: Benefit (EPA+DHA and Se) and risk (MeHg) assessment through the consumption of selected fish species.

This study aimed to assess the risk-benefit balance associated to fish consumption by Portuguese preschool children. For this purpose, databases (from IPMA and literature) were mined and mathematically processed by a model based on the Extreme Value Theory assuming consumption scenarios. Eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) and selenium (Se) and methylmercury (MeHg) were selected as critical components of fish, given their health impact and significant contents in some fish species. Assessment also took into account that Se may protect against MeHg toxicity. With exception of blue shark, Se Health Benefit Value (Se-HBV), was always positive (ranging between 3.3 and 14.9) and Se:MeHg ratio was always higher than one (3.8 to 32.3). It was also estimated that the deleterious effects of MeHg on children IQ were offset by the beneficial impact of EPA+DHA in fish except for grilled black scabbardfish consumed every day. Blue shark, regardless of the culinary treatment, yielded very high probabilities of exceeding MeHg TWI (higher than 84 % with a single weekly meal), thus raising serious concerns. EPA+DHA benefits were high in salmon regardless of culinary treatment (> 84 %). Fish consumption by children is advisable with exception of blue shark and boiled and grilled tuna.

Composition and bioaccessibility of elements in green seaweeds from fish pond aquaculture.

The elemental composition of five species of green seaweeds (Chaetomorpha linum, Rhizoclonium riparium, Ulva intestinalis, Ulva lactuca, Ulva prolifera) grown in fish pond aquaculture systems were studied. The elemental bioaccessibility in these species was also investigated through the application of an innovative in vitro digestive model of the human gastrointestinal tract. It was observed that R. riparium had the highest levels of Mn, Sr, Cd, Sn, and I and that U. lactuca had the highest Ni and Cu concentrations. The daily amounts of dried green seaweed required for achieving specific dietary intakes were calculated, namely: 7g of dried U. lactuca (for meeting Cu Recommended Daily Allowance, RDA); 173g of dried U. lactuca (Zn RDA); 78g of dried C. linum (Se RDA); 41g of dried C. linum (Mo RDA); and 0.5g of dried R. riparium (I Dietary Reference Intake, DRI). Concerning elemental bioaccessibility, Mn and Cu had the highest values, always above 50%, I values were in the lower range, between 14 and 31%. The elemental bioaccessibility range of R. riparium (31-100%) was higher than the ranges for other species, particularly C. linum (0-56%). The bioaccessibility results entailed higher quantities of dried seaweed for reaching dietary intakes: 10g of dried U. lactuca (Cu RDA); 290g of dried R. riparium (Zn RDA); and 2g of dried R. riparium (I DRI). Accordingly, R. riparium is a very rich I source. This study showed the importance of taking into account bioaccessibility results in estimating dietary intakes.

Microalgae as healthy ingredients for functional food: a review.

Microalgae are very interesting and valuable natural sources of highly valuable bioactive compounds, such as vitamins, essential amino acids, polyunsaturated fatty acids, minerals, carotenoids, enzymes and fibre. Due to their potential, microalgae have become some of the most promising and innovative sources of new food and functional products. Moreover, microalgae can be used as functional ingredients to enhance the nutritional value of foods and, thus, to favourably affect human health by improving the well-being and quality of life, but also by curtailing disease and illness risks. This review provides an overview of the current knowledge of the health benefits associated with the consumption of microalgae, bioactive compounds, functional ingredients, and health foods.

Evaluation of the risk/benefit associated to the consumption of raw and cooked farmed meagre based on the bioaccessibility of selenium, eicosapentaenoic acid and docosahexaenoic acid, total mercury, and methylmercury determined by an in vitro digestion model.

The bioaccessibility of total lipids, EPA, DHA, Se, Hg, and MeHg in raw and cooked meagre (Argyrosomus regius) was studied by using an in vitro digestion method. A risk-benefit assessment of raw and cooked meagre on the basis of the bioaccessibility data was carried out. The bioaccessibility of total lipids was generally high in raw and cooked meagre with exception of grilled fish. For EPA and DHA, bioaccessibility percentages were low never surpassing the 50% in raw, boiled, and grilled meagre. The bioaccessibility percentage of Se was equal or higher than 82% (grilling treatment). Likewise, for Hg and MeHg, high bioaccessibility values were determined with exception of grilled meagre, displaying lower values of 54% and 64%, respectively. The risk-benefit probabilistic assessment brought about a recommendation of a maximum consumption of two weekly meals for boiled or roasted meagre and three weekly meals for grilled meagre.

Relationship between BMI and body fatness in three European countries.

BACKGROUND/OBJECTIVES: Body fatness and heart disease risk factors can differ considerably between ethnities for a given body mass index (BMI). Information is lacking on differences between various Caucasian populations within Europe. The aim was to investigate the differences in anthropometrics and risk factors between adults from Iceland, Spain and Ireland. SUBJECT/METHODS: This was a secondary analysis of the baseline data from the SEAFOODplus YOUNG intervention study, in which 324 subjects (20-40 years, BMI 27.5-32.5 kg/m(2), from Iceland, Spain and Ireland) participated. Fasting glucose, insulin, blood lipids and body compossition were measured, insulin resistance was calculated using the homeostasis model assessment of insulin resistance. RESULTS: Although age and BMI did not differ between Spanish, Irish and Icelandic subjects, Irish subjects had significantly higher waist circumference (3.2 and 6.7 cm) and body fat percentage (4.4 and 2.0%) compared with Icelandic and Spanish participants, respectively. Irish participants had also more unfavorable cardio-metabolic risk factors compared with Spanish and Icelandic subjects. However, correction for waist attenuated the observed differences considerably, in particular for total cholesterol, low-density lipoprotein and triglycerides. CONCLUSIONS: Despite having near identical BMI and age, our results show that study participants from different populations within Europe differ considerably in cardio-metabolic risk factors, partly due to differences in body fat distribution.

Effects of weight loss and seafood consumption on inflammation parameters in young, overweight and obese European men and women during 8 weeks of energy restriction.

BACKGROUND/OBJECTIVES: In vitro studies have shown that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) can affect inflammation; however, results from intervention studies in overweight or obese individuals are contradicting. The aim of this study was to investigate the effects of weight loss and seafood consumption on inflammation parameters during energy restriction. SUBJECTS/METHODS: In this 8-week intervention trial, 324 subjects (aged 20-40 years, body mass index 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland) were randomized to one of four energy-restricted diets (-30% relative to estimated requirements): salmon (3 x 150 g/week, 2.1 g LC n-3 PUFA per day); cod (3 x 150 g/week, 0.3 g LC n-3 PUFA per day); fish oil capsules (1.3 g LC n-3 PUFA per day); and control (sunflower oil capsules, no seafood). Body weight, high-sensitivity C-reactive protein (CRP), interleukin-6 (IL-6), glutathione reductase and prostaglandin F2 alpha (PGEF2alpha) were measured at baseline and end point. RESULTS: Subjects experienced weight loss (-5.2+/-3.2 kg, P<0.001). Taken together for all subjects, there were significant decreases in all inflammation parameters. On a group level, salmon consumption was most effective, three of the four inflammation parameters decreased in the salmon group (high-sensitivity CRP=-32.0%; IL-6=-18.4%; PGEF2alpha=-18.5%; all P<0.05). Cod consumption decreased high-sensitivity CRP and IL-6 (-21.5 and -10.8%, respectively, both P<0.05). Changes in the other two groups were not significant, which can be partly explained by the large s.d. CONCLUSIONS: The mean concentrations of inflammation parameters decreased during a period of weight loss and dietary intervention. In our study, salmon consumption was most effective, three of the four measured inflammation parameters decreased significantly in the salmon group.

Inclusion of fish or fish oil in weight-loss diets for young adults: effects on blood lipids.

OBJECTIVE: To assess the effects of fish (lean or oily) and fish oil consumption on blood lipid concentration during weight loss. DESIGN: Randomized, controlled 8-week trial of energy-restricted diet varying in fish and fish oil content. Subjects, 324 men and women, aged 20-40 years, body mass index 27.5-32.5 kg m(-2), from Iceland, Spain and Ireland, were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood), (2) cod diet (3 x 150 g week(-1)), (3) salmon diet (3 x 150 g week(-1)), (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups were single-blinded. MEASUREMENTS: Total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein cholesterol, triacylglycerol (TG) and anthropometrics were measured at baseline and end point. RESULTS: The difference in logTG lowering between the control group and the cod diet, salmon diet and fish oil from baseline to end point was -0.036 (95% CI -0.079 to 0.006), -0.060 (-0.101 to -0.018) and -0.037 (-0.079 to 0.006), respectively. Reduction in TC was about 0.2 mmol l(-1) greater in the fish groups (cod and salmon) than in the control group, but only of borderline significance when adjusting for weight loss. HDL tended to decrease less in the diet groups consuming a significant amount of n-3 fatty acids (salmon and fish oil). CONCLUSION: Weight-loss diet including oily fish resulted in greater TG reduction than did a diet without fish or fish oil. Controlled trials using whole fish as a test meal are encouraged to be able to elucidate the role of different constituents of fish for human health.

Beneficial effects of long-chain n-3 fatty acids included in an energy-restricted diet on insulin resistance in overweight and obese European young adults.

AIMS/HYPOTHESIS: Epidemiological research indicates that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) improve insulin resistance. The aim of this study was to investigate the effects of seafood consumption on insulin resistance in overweight participants during energy restriction. METHODS: In this 8 week dietary intervention, 324 participants (20-40 years, BMI 27.5-32.5 kg/m(2), from Iceland, Spain and Ireland) were randomised by computer to one of four energy-restricted diets (-30E%) of identical macronutrient composition but different LC n-3 PUFA content: control (n = 80; no seafood; single-blinded); lean fish (n = 80; 150 g cod, three times/week); fatty fish (n = 84; 150 g salmon, three times/week); (4) fish oil (n = 80; daily docosahexaenoic/eicosapentaenoic acid capsules, no other seafood; single-blinded). Fasting glucose, insulin, adiponectin, plasma triacylglycerol and fatty acids in erythrocyte membrane were measured at baseline and endpoint. Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). Linear models with fixed effects and covariates were used to investigate the effects of seafood consumption on fasting insulin and HOMA-IR at endpoint in comparison with the control group. RESULTS: Of the participants, 278 (86%) completed the intervention. Fish oil intake was a significant predictor of fasting insulin and insulin resistance after 8 weeks, and this finding remained significant even after including weight loss, triacylglycerol reduction, increased LC n-3 PUFA in membranes or adiponectin changes as covariates in the statistical analysis. Weight loss was also a significant predictor of improvements. CONCLUSIONS/INTERPRETATION: LC n-3 PUFA consumption during energy reduction exerts positive effects on insulin resistance in young overweight individuals, independently from changes in body weight, triacylglycerol, erythrocyte membrane or adiponectin. TRIAL REGISTRATION: ClinicalTrials.gov NCT00315770.

Randomized trial of weight-loss-diets for young adults varying in fish and fish oil content.

OBJECTIVE: To investigate the effect of including seafood and fish oils, as part of an energy-restricted diet, on weight loss in young overweight adults. DESIGN: Randomized controlled trial of energy-restricted diet varying in fish and fish oil content was followed for 8 weeks. Subjects were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood); (2) lean fish (3 x 150 g portions of cod/week); (3) fatty fish (3 x 150 g portions of salmon/week); (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups, were single-blinded. SUBJECTS: A total of 324 men and women aged 20-40 years, BMI 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland. MEASUREMENTS: Anthropometric data were collected at baseline, midpoint and endpoint. Confounding factors were accounted for, with linear models, for repeated measures with two-way interactions. The most important interactions for weight loss were (diet x energy intake), (gender x diet) and (gender x initial-weight). RESULTS: An average man in the study (95 kg at baseline receiving 1600 kcal/day) was estimated to lose 3.55 kg (95% CI, 3.14-3.97) (1); 4.35 kg (95% CI, 3.94-4.75) (2); 4.50 kg (95% CI, 4.13-4.87) (3) and 4.96 kg (95% CI, 4.53-5.40) on diet (4) in 4 weeks, from baseline to midpoint. The weight-loss from midpoint to endpoint was 0.45 (0.41-0.49) times the observed weight loss from baseline to midpoint. The diets did not differ in their effect on weight loss in women. Changes in measures of body composition were in line with changes in body weight. CONCLUSION: In young, overweight men, the inclusion of either lean or fatty fish, or fish oil as part of an energy-restricted diet resulted in approximately 1 kg more weight loss after 4 weeks, than did a similar diet without seafood or supplement of marine origin. The addition of seafood to a nutritionally balanced energy-restricted diet may boost weight loss.

Conjugated linoleic acid in diets for large-size rainbow trout (Oncorhynchus mykiss): effects on growth, chemical composition and sensory attributes.

The effects of graded levels (0 %, 0.5 %, 0.75 and 1 %) of dietary conjugated linoleic acid (CLA) were assessed on 97 g rainbow trout. Fish were fed to satiation twice a day for 12 weeks. At the end of the experiment, all groups of fish weighed more than 250 g and no significant differences were detected in growth performance, feed conversion, nutrient or energy utilisation or body composition between treatments. A decrease in liver lipid content resulted from including CLA and was accompanied by a reduction in malic enzyme activity. The muscle saturated acid and PUFA content did not vary between dietary treatments, despite the increasing concentration of stearic acid and CLA. In the liver, however, both fractions increased significantly with dietary CLA. Moreover, the MUFA decreased significantly in both muscle and liver. CLA was incorporated into tissue lipids, with levels in flesh (2.1-4.2 %) being 2-fold higher than in liver (0.8-1.9 %). In muscle, the percentage of cis-9, trans-11 isomer ranged from 39.5 % to 41.8 % and that of trans-10, cis-12 isomer from 31.4 % to 33.4 % of total CLA. The incorporation of CLA isomers in the liver varied with dietary treatment, and the cis-9, trans-11 isomer seemed to be more efficiently incorporated than trans-10, cis-12. Sensory data indicated slight-to-moderate differences between the trout fed with and without CLA. The present results suggest that 250 g rainbow trout can incorporate CLA in both muscle and liver, contributing to the production of a functional food.