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The effect of various protease and carbohydrase treatments on the extraction of polyphenols and other antioxidant ingredients from the red algae Palmaria palmata (dulse) was investigated. In addition, the relative contribution of different fractions to the overall antioxidant capacity of the hydrolyzate was evaluated. Considerable differences were observed both in total phenolic content (TPC) and antioxidant activities of the hydrolysates evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorbance capacity (ORAC) and ferrous ion-chelating ability assays . All the proteases tested had significant enhancing effect on the extraction of polyphenols and other active components compared to carbohydrases and cold water extraction (control). The Umamizyme extract had the highest TPC and consequently exhibited the strongest scavenging capacity against DPPH and peroxyl radicals. Further fractionation of the Umamizyme extract revealed that the crude polyphenol fraction possessed the highest peroxyl radical scavenging activity, whereas the crude polysaccharide fraction was more effective for chelating ferrous ions. The data from this study suggest the potential of protease treatment to improve value-added utilization of dulse extracts as antioxidants in functional foods and nutraceuticals.

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Brown seaweed Fucus vesiculosus has a high potential as a source of natural antioxidants due to a high diversity of bioactive compounds in its composition. In this study, four extracts were characterized with respect to composition of bioactive compounds, in vitro antioxidant properties and their partitioning between water and octanol. Additionally, the antioxidant activity of the extracts was evaluated in a fish-oil-enriched mayonnaise. Acetone and ethanol were found to extract the highest amount of phenolic compounds and carotenoids. Water used as extraction solvent, extracted some phenolic compounds but also higher amount of metals and chlorophyll derivatives. It was proposed that extracts with high phenolic content and low iron content, such as the acetone and ethanol extract, would have the highest potential as antioxidants in foods. This was confirmed in the storage trial, where these extracts showed higher antioxidant activity.

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Diet plays an important role in the etiology of hypertension. Blood pressure (BP) -lowering properties of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) are promising. The aim was to investigate whether different formulations of fish oil differently affect blood pressure in community-dwelling adults. The hypothesis was that fish oil formulations would improve BP in comparison with a placebo.
In this 4-week randomized, placebo-controlled, doubly-blinded dietary intervention study, participants (N = 99,> 50 years) from the capital area of Iceland were randomized into three groups. Group 1 (n = 38) received 6 meals / week fortified with a liquid fish oil and placebo powder. Group 2 (n = 30) received conventional (unfortified) meals and microencapsulated powder. Group 3 (n = 31) was the control group which received conventional meals and placebo powder. Calculated on a weekly basis, the amount of EPA + DHA provided was 1.5 g / d. Systolic (SBP) and diastolic BP (DBP) were measured before and after the intervention period.
Seventy-seven subjects finished the study (77.8%). Drop-out rates were not different between groups. According to multivariate statistics, endpoint SBP was lower in Group 1 (-7.0 mmHg, p = 0.037) and in Group 2 (-7.2 mmHg, p = 0.037) as compared with Group 3. There was no significant difference in DBP between the groups .
Our study shows that LC n-3 PUFA from microencapsulated powder are equally effective to significantly reduce SBP as LC n-3 PUFA from meals enriched with liquid fish oil in comparison with a control group.

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Limited knowledge is currently available on the influence of fish thawing and subsequent storage conditions on bacterial growth kinetics, succession, and diversity alongside the production of biogenic amines. This study aimed to address these factors during the thawing and subsequent storage of mackerel. Thawing was either done fast in 18 ° C water for 2 h or slowly at 30 ° C overnight. Subsequent storage was at 30 ° C (ambient) for 36 h and 2 to 5 ° C (refrigerated) for 12 days. The cultivation methods used were total viable counts, hydrogen sulfide – producing bacteria, and Pseudomonas. Maximum growth rate, population density, and lag time were fitted on the counts using the Baranyi model. The bacterial diversity and succession were based on sequencing of 16S rRNA amplicons, and biogenic amines were quantified on high-pressure liquid chromatography – UV. The results show that lag time of hydrogen sulfide – producing bacteria was significantly affected by both thawing methods, and further, the interaction between thawing and storage significantly affected the maximum growth rate of these bacteria. However, the maximum growth rate of Pseudomonas was higher during refrigerated storage compared to storage at ambient temperature. Total viable counts showed longer lag time and reduced growth rate during refrigerated storage. Higher bacterial diversity was correlated to slow thawing and storage at ambient temperature compared with slow thawing and refrigerated storage. Overall, Acinetobacter and Psychrobacter genera were the dominant bacterial populations. The amine levels were low and could not be differentiated along the thawing and storage approaches, despite a clear increase in bacterial load, succession, and diversity. This corresponded well with the low abundance of biogenic amine – producing bacteria, with the exception of the genus Proteus, which was 8.6% in fast-thawed mackerel during storage at ambient temperature. This suggests that the decarboxylation potential is dependent on both microbial load and microbial community structure.

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Marine microbial biogeography describes the occurrence and abundance of microbial taxa and aims to understand the mechanisms by which they are dispersed and then adapt to their environment. The development of novel technologies, such as Next-Generation Sequencing (NGS) in combination with large-scale ocean sampling campaigns, generated a vast amount of taxonomic data that allowed for in-depth analyzes of biogeographic patterns. Globally occurring groups of microorganisms were detected that dominate the marine environment (eg, SAR11, SAR86, Roseobacter, and Vibrio), however, NGS data revealed the presence of distinct eco- and phylotypes within these clades and genera that showed clear ecological niche adaptation and different biogeographic distributions. Genome analyzes of these marine microorganisms helped to understand potential adaptive mechanisms that could explain why certain taxa are occurring ubiquitously and others are limited to certain regions and ecosystems. Marine microorganisms can employ a vast variety of adaptive mechanisms to deal with environmental parameters such as temperature, light or nutrient availability, for example through exploitation of specific energy sources or protective mechanisms against UV radiation or viruses. The availability or lack of physiological pathways and traits in ecotypes is then responsible for shaping the marine microbial biogeography.

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BACKGROUND

The ability of different in vitro antioxidant assays to predict the efficiency of cod protein hydrolyzate (CPH) and Fucus vesiculosus ethyl acetate extract (EA) towards lipid oxidation in haemoglobin-fortified washed cod mince and iron-containing cod liver oil emulsion was evaluated. The progression of oxidation was followed by sensory analysis, lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) in both systems, as well as loss of redness and protein carbonyls in the cod system.

RESULTS

The in vitro tests revealed high reducing capacity, high DPPH radical scavenging properties and a high oxygen radical absorbance capacity (ORAC) value of the EA which also inhibited lipid and protein oxidation in the cod model system. The CPH had a high metal chelating capacity and was efficient against oxidation in the cod liver oil emulsion.

CONCLUSION

The results indicate that the F. vesiculosus extract has a potential as an excellent natural antioxidant against lipid oxidation in fish muscle foods while protein hydrolysates are more promising for fish oil emulsions. The usefulness of in vitro assays to predict the antioxidant properties of new natural ingredients in foods thus depends on the knowledge about the food systems, particularly the main pro-oxidants present. © 2015 Society of Chemical Industry

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In this chapter the current knowledge of the diversity of piezophiles isolated so far is reviewed. The isolated piezophiles originated from high-pressure environments such as the cold deep sea, hydrothermal vents, and crustal rocks. Several "stress" conditions can be experienced in these environments, in particular high hydrostatic pressure (HHP). Discoveries of abundant life in diverse high-pressure environments (deep biosphere) support the existence and an adaptation of life to HHP. At least 50 piezophilic and piezotolerant Bacteria and Archaea have been isolated from different deep-sea environments but these do not by far cover the large metabolic diversity of known microorganisms thriving in deep biospheres. The field of biology of piezophiles has suffered essentially from the requirements for high-pressure retaining sample containers and culturing laboratory equipment, which is technically complicated and expensive. Only a few prototypes of HHP bioreactors have been developed by a number of research groups and this could explain the limited number of piezophiles isolated up till now.

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Brown seaweed Fucus vesiculosus has a high potential as a source of natural antioxidants due to a high diversity of bioactive compounds in its composition. In this study, four extracts were characterized with respect to composition of bioactive compounds, in vitro antioxidant properties and their partitioning between water and octanol. Additionally, the antioxidant activity of the extracts was evaluated in a fish-oil-enriched mayonnaise. Acetone and ethanol were found to extract the highest amount of phenolic compounds and carotenoids. Water used as extraction solvent, extracted some phenolic compounds but also higher amount of metals and chlorophyll derivatives. It was proposed that extracts with high phenolic content and low iron content, such as the acetone and ethanol extract, would have the highest potential as antioxidants in foods. This was confirmed in the storage trial, where these extracts showed higher antioxidant activity.

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