The content of phenolic compounds in chocolate depends on the processing of the cocoa from bean to bar. The aim of this study was to determine the fate of phenolic compounds and theobromine in cocoa beans during roasting at different temperatures. Based on a screening of 12 cocoa bean sorts, three beans (NM, NCC, and NB) with initial high total phenolic content (TPC) were selected for the roasting trial (100 and 150 degrees C up to 20 min). The concentration of three major flavonoids ((-)-catechin, (-)-epicatechin and procyanidin B2) and one methylxanthine (theobromine) were evaluated in both raw and roasted beans. Results showed changes in the concentration of flavonoids and theobromine during roasting. Roasting at 150 degrees C for 15 min was optimal for maintaining high flavonoid levels while reducing theobromine levels. However, sensory evaluation on final product is needed to confirm whether the suggested roasting condition would also result in a final product with pleasant sensory properties. Identification of the most abundant phenolic compounds and theobromine by UHPLC-MS. Increased (-)-catechin was found to be a result of epimerization in cocoa beans by roasting (<= 150 degrees C). image

Drying is an important post-harvest process to preserve seaweed as they are highly susceptible to spoilage due to their high moisture content. Drying can be performed in multiple ways by changing the temperature, pressure, air flow, and humidity. Therefore, the choice of drying method can affect the quality of the product in terms of sensory, chemical, and physicochemical properties. Seaweeds contain nutrients (protein, lipids, carbohydrates, vitamins, and minerals) and bioactive compounds. The compounds impact properties such as texture, taste, odor, and appearance. However, there is currently limited knowledge about how different drying methods affect the quality of seaweed products. In this paper we demonstrate, how different drying methods: i) convective drying (52 °C), ii) microwave-vacuum drying (-40 to 40 °C at 10 Pa), and iii) freeze-drying (-20 to 20 °C at 20 Pa) influence the food quality of Fucus vesiculosus and Ulva sp. by investigating physico-chemical properties such as water holding capacity, water absorption, and color, the changes in some of the chemical compounds such as macronutrients, fatty acids, amino acids, antioxidants, and pigments, as well as the taste, odor, appearance, and texture within sensory attributes. This study found that different drying methods have a species-dependent influence on the quality of seaweed, with Ulva sp. showing more similarities of using microwave-vacuum and freeze-drying methods, while the drying method for F. vesiculosus should be selected based on the desired food quality due to significant variations between the drying methods.

This study aimed at extracting lipophilic and hydrophilic compounds from Nordic brown seaweed Fucus vesiculosus and to evaluate the extract’s ability to maintain the physical and oxidative stability of fish oil-enriched mayonnaise (80% fat, 1:4 fish oil: rapeseed oil) during storage (dark, up to 28 days). Three different types of extracts were obtained, one using supercritical carbon dioxide (lipophilic extract) and two using subcritical water extraction (hydrophilic extracts)—one on dry seaweed (Subcritical water extract (SCWE) and one on the residue from supercritical carbon dioxide extraction after extracting the lipophilic compounds (Subcritical water extract (SCWER). The extracts were characterized with respect to their antioxidant composition and in vitro antioxidant properties. Moreover, the extracts were added in concentrations of 2 g/kg mayonnaise, both individually or in combination to study synergistic effects between antioxidants with different polarity and locations in the mayonnaise system. Results showed that both types of extractsdelayed the oxidation of lipids; The hydrophilic extracts (SCWE and SCWER) were able toretard the formation of hydroperoxides, and subsequent formation of secondary oxidation products. However, no synergetic effect was found for the hydrophilic and hydrophobic extracts when they were applied in different phases of the mayonnaise. The metal chelating ability is suggested to be responsible for the observed better performance of the hydrophilic extracts. However, further studies are required to understand which specific components in the extract have contributed to metal chelating ability. In conclusion, the findings of the present study suggest hydrophilic and hydrophobic compounds from the Nordic seaweed F. vesiculosus can retard lipid oxidation in mayonnaise.

Phlorotannins play a role in biological functions to protect the cells against UV and oxidative damage in brown algae. We hypothesized that these compounds can function as photo-protectors and antioxidants in skin care formulations. Two types of extracts (water (FV-WE) and 67% v/v ethanol (FV-EE)) from Fucus vesiculosus were obtained with a phlorotannin content between 7−14% in dry extract. Exposure to sun light during growth was included as a factor on the phlorotannin content but did not influence the phlorotannin content. However, green colored F. vesiculosus had lower total phenolic content (TPC) (FV-WE = 6.9 g GAE 100 g−1 dw, FV-EE = 7.8 g GAE 100 g−1 dw) compared to those with a yellow/brownish color (FV-WE = 10.4–13.7 g GAE 100 g−1 dw, FV-EE = 11.2–14.0 g GAE 100 g−1 dw). UVA and UVB photo protective capabilities of the extracts through different biological effective protection factors (BEPFs) were evaluated using in vitro methods; the Mansur method for sun protection factor (SPF) and calculation of effective solar absorption radiation (%ESAR) to determine SPF and UVA protection factor (UVA-PF) of the extract and in seaweed enriched lotion. The SPF was negligible, when evaluating FV-WE in lotion (10 and 20% w/w). Moreover, %ESAR of the FV-WE showed SPF and some UVA-PF, but not enough to give sufficient SPF in lotions (10% w/w). It was concluded that the concentration of UV protecting compounds in the extracts was too low to and that further fractionation and purification of phlorotannins is needed to increase the SPF.

Enriching foods with long-chain (LC) n-3 polyunsaturated fatty acids (PUFAs) requires a delivery emulsion system, which is both thermodynamically and oxidatively stable. The antioxidant and stabilizing properties of three types of polysaccharide extracts from brown algae Saccharina latissima with mixed composition of polysaccharides (SA: 98% Sodium alginate, SF: 90% alginate and 9% fucoidan, SL: 14.5% fucoidan, 9.5% laminarin and co-extracted non-polysaccharides) were evaluated. SA, SF, SL and REF (added commercial sodium alginate) all showed in vitro ferrous ion chelating ability in the order: SA(99%)>SL(78%)>REF(31%)>SF(16%). The difference in antioxidant activity between SA, REF and SF appeared related to structural differences of alginate (M/G ratio). A storage trial was conducted using 70% (w/w) fish oil-in-water delivery emulsions added sodium caseinate (NaCas) (0.23 wt%) as emulsifier in combination with SA, SF, SL or commercial NaAlg (REF) in different concentrations (C1=0.1, C2=0.2 C3=0.3 and C4=0.4 wt%). A control with only NaCas were included (CON). The physical (e.g. creaming and droplet-size distribution) and oxidative (peroxide value and volatiles) stability of the emulsions, were evaluated (12 days, dark at 20˚C). Acceptable physical stability (creaming index, CI) was found for, REF (all concentrations), SF=0.2 wt% (C2), SL and SA=0.3 wt% (C3) and 0.4 wt% (C4). In general, the oxidative stability decreased by adding REF, SA and SF (except for REF at C1), as prooxidant activity was observed. However, SA showed antioxidant activity against formation of 2-ethylfuran. SL showed antioxidant activity in decreasing formation of volatile compounds in emulsions when added in concentrations above 0.2 wt%.

Physical and oxidative stability of high-fat fish-oil emulsions added algae-based stabilizers from Saccharina latissima . Abstract from 30th Nordic Lipidpforum Symposium 2019, Horsens,

This study investigates the stabilization of fish oil‐loaded electrosprayed capsules with different natural antioxidants: i) an ethanol extract from the brown alga Fucus vesiculosus; or ii) a combination of δ‐tocopherol and rosemary extract. The seaweed extract enhances the oxidative stability of fish oil‐loaded capsules with dextran as the main biopolymer wall material, but shows a prooxidant effect in fish oil‐loaded capsules having glucose syrup as the main biopolymer. These results can mainly be explained by the higher encapsulation efficiency of dextran capsules when compared to glucose capsules (90 vs. 83–85%), which prevents interaction of metal ions present in the extract with non‐encapsulated oil. On the contrary, the addition of a lipophilic radical scavenger such as δ‐tocopherol in combination with synergistic antioxidants such as carnosic acid and carnosol present in rosemary extract improves the oxidative stability of glucose syrup capsules during 21 day storage, but not when the capsules are added to mayonnaise. Moreover, the capsule‐containing mayonnaise presents a larger droplet size and higher apparent viscosity than mayonnaise enriched with neat fish oil. Both findings indicate that the structure of capsules may have been lost when added to a water‐based food matrix (e.g., mayonnaise) and this requires further investigation. Practical Applications: Novel omega‐3 delivery systems that are more easily dispersed and still maintain their oxidative stability are needed by the food industry. Electrosprayed capsules with a reduced size when compared to spray‐dried capsules, and which are produced without the need of heat for drying emulsions are promising omega‐3 powdered encapsulates. Moreover, the addition of natural antioxidants, commonly used by the industry to further stabilize omega‐3 encapsulates, deserves scientific attention. This study reveals the effect of seaweed antioxidants (e.g., phlorotannins) and commercial natural antioxidants (e.g., δ‐tocopherol and rosemary extract) on the oxidative stability of electrosprayed capsules loaded with fish oil. In addition, the effect of adding the capsules to a food matrix such as mayonnaise has been investigated. Although further development is necessary, these results will open up new strategies to enrich food products with omega‐3 polyunsaturated fatty acids. Fish oil‐loaded electrosprayed capsules stabilized with antioxidants. This study investigates the stabilization of fish oil‐loaded electrosprayed capsules with different natural antioxidants: i) an ethanol extract from the brown alga Fucus vesiculosus; or ii) a combination of δ‐tocopherol and rosemary extract.

Objective The purpose of this study was to identify an effective lipid oxidation initiator which could predict, within 1 month, the long-term oxidative stability of a prototype skincare formulation. The main purpose was to find a potential initiator not to assess oxidation stability of the formulations. Methods Four initiators (below) were examined in three steps: Reaction kinetics using a Clark electrode (Oxygraph); Effect of adding an initiator on the product's physical and oxidative stability in prototype skincare formulations by visual observation, peroxide value and headspace GC-MS determination of volatile oxidation products; and Ability to differentiate unstable vs. stable prototype creams by initiator addition. The four initiators explored were: FeCl2/H2O2, FeCl3/ascorbic acid, 2,2 '-Azobis(2,4-dimethylvaleronitrile) (AMVN) and 2,2 '-Azobis(2-methylpropionamidine) dihydrochloride (AAPH) Results In Oxygraph, the initiator systems FeCl2/H2O2 and FeCl3/ascorbic acid were good accelerators of oxygen consumption. The addition of FeCl2/H2O2 to prototype formulations did not affect the physical stability. However, the addition of FeCl3/ascorbic acid to prototype formulations resulted in phase separation and FeCl3/ascorbic acid was therefore deemed unusable. Moreover, the addition of AAPH or AMVN resulted in an increased and decreased viscosity respectively. In the oxidation stability study, peroxide value increased significantly when AMVN was added. However, the peroxide value remained low for the other initiators and the control (no initiator). The secondary volatile oxidation product, butanal, increased most with the FeCl2/H2O2 addition. Three out of the four initiators did not have the ability to rank the stable and unstable formulations in accordance with the result obtained for volatile oxidation products after 42 days of storage at 20 degrees C of formulations without initiator. Only, FeCl2/H2O2 was able to rank the formulations in accordance with the oxidative stability observed for volatile oxidation products after 42 days of storage. Conclusion FeCl2/H2O2 showed potential as an initiator to predict the oxidative stability of skincare formulations, but more studies are needed to confirm the result in a broader range of products over a longer time.

Driven by a general demand for clean labels on food and cosmetic products, these industries are currently searching for efficient natural antioxidants to replace synthetic antioxidants. Seaweed contains several compounds with antioxidative properties (phlorotannins, pigments, tocopherols, and polysaccharides). It is possible to extract these compounds via different extraction techniques, which are discussed in this review. Among the abovementioned compounds, phlorotannins are probably the most important in terms of the antioxidative potential of seaweed extracts. We review how the different antioxidative compounds can be characterized. We discuss the current knowledge of the relationship between phlorotannin's structure and antioxidant properties in in vitro studies as well as in food systems. Concerning food systems, most studies on the antioxidative effect of seaweed extracts have been performed with extracts prepared from Fucus vesiculosus, despite the fact that this species is less available than other species, such as Ascophyllum nodosum, which also has high phlorotannin content.

Skin-care products are known delivery systems of functional lipids that can enhance the natural defense of skin. Unsaturated lipids, e.g., linoleic acids, are more susceptible to lipid oxidation than saturated lipids. Therefore, lipid oxidation must be prevented to preserve the functionality of the unsaturated lipids in skin-care products. The antioxidant properties of two Fucus vesiculosus extracts (water extract [WE] and 80% [v/v] ethanol extract [EE]) were evaluated. Both extracts had high in vitro antioxidant properties and a high phenolic content. The antioxidant efficacy of the extracts was evaluated by addition of 0.05% and 0.1% (w/w) freeze-dried extracts to facial cream formulations. The cream was stored up to 42 days (dark, 20 degrees C) and the oxidative stability was determined by following tocopherol consumption and development in peroxides and secondary oxidation products. The results showed that EE was able to reduce the peroxide oxidation rate from 84.8% (control without extract) to 41.3%. Furthermore, a higher efficacy was observed for EE over WE. This was most likely related to higher phenolic content, high radical-scavenging activity, and moderate metal-chelating ability. However, WE indicated regeneration of tocopherols by amphiphilic polyphenolic phlorotannins, with interfacial properties. The results show that F. vesiculosus extracts rich in antioxidative phlorotannins can play an important role in reducing lipid oxidation and maintaining the quality of cream.

Brown algae are rich in polyphenolic compounds, phlorotannins, which have been found to possess high in vitro antioxidant capacity, especially DPPH radical scavenging activity, due to the high number of hydroxyl groups. Whereas, the overall antioxidant capacity of brown algae extracts has been widely studied, the antioxidant capacity of individual phlorotannins has been rarely explored. The aim of this study was to determine the structure dependant antioxidant capacity of phlorotannins from Icelandic brown algae, Fucus vesiculosus. The antioxidant capacity of individual phlorotannins was determined by an on-line method using liquid chromatography and an electrochemical detector followed by quadrupole Time of Flight mass spectrometry (UHPLC-DAD-ECD-QTOFMS). Tentative structural elucidation of 13 phlorotannin isomers from EAF was obtained by LC-DAD-QTOFMS, ranging from 374 to 870Da. On-line determination of antioxidant capacity of the individual phlorotannins generally showed that low molecular phlorotannins exhibited higher antioxidant capacity and that the capacity decreased with polymerisation.

Seaweed contains a wide range of antioxidant substances with potential to be used in the development of new natural ingredients for the food, cosmetic, and pharmaceutical industry. Such ingredients can act as natural preservatives for preventing product deterioration during storage, in particular in the form of rancidity due to oxidation of unsaturated fatty acids in, e.g., food products. In this chapter, the occurrence and antioxidative properties of seaweed-derived substances will be discussed in relation to lipid oxidation in functional food products. This research area is relatively new, and only the antioxidant activity of extracts from brown algae Fucus vesiculosus has been thoroughly studied in different functional food products rich in unsaturated fatty acids.

A water and an acetone extract of the Icelandic brown algae Fucus vesiculosus were evaluated as potential natural sources of antioxidant compounds in skin care emulsions. To assess their efficacy in inhibiting lipid oxidation caused by photo‐ or thermoxidation, they were stored in darkness and room temperature as control conditions, and compared to samples stored under accelerated conditions (light and room temperature, or darkness and 40°C). The presence of extracts in the skin care emulsions induced remarkable colour changes when the emulsions were exposed to light, and more extensively under high temperature. High temperature also caused greater increments in the droplet size of the emulsions. The analysis of the tocopherol content, peroxide value and volatile compounds during the storage revealed that, whereas both water and acetone extracts showed (at 2 mg/g of emulsion) protective effect against thermooxidation, only the water extract showed antioxidant activity against photooxidation.Practical applications: This research is the basis of developing natural antioxidants derived from seaweed to limit lipid oxidation in skin care products.Skin care emulsions are exposed to light (A+) or elevated storage temperatures (H0) to promote lipid oxidation during storage. Control samples are stored at ambient temperatures in the dark (A0). Two Icelandic brown alga Fucus vesiculosus extracts, water (WE) and acetone (AE) extract, were added as natural antioxidants to control lipid oxidation and ensure a stable product. Both extract (depending on concentration, 1 or 2) decreased photooxidation of skin care emulsions compared to the reference (REF) without added extract, as decreased formation of secondary volatile oxidation products was observed. However, the presence of extracts in the skin care emulsions induced remarkable colour changes during storage. Moreover, samples exposed to elevated storage temperatures increased oil droplet size and resulted in disrupted emulsion structure (syneresis) by day 35.

The aims of this study were to (i) investigate the ability of Icelandic brown algae Fucus vesiculosus extracts to inhibit lipid oxidation in granola bars fortified with fish oil‐in‐water emulsion; (ii) investigate whether addition of the seaweed extracts affected the physical microstructure of the oil droplets in granola bars. The oxidative stability of the bars at 20°C was evaluated over a period of 10 wk by measuring the development of peroxides and volatile compounds using dynamic headspace gas chromatography mass spectrometry (DHS GC‐MS). The physical microstructure was determined using microscopy. All extracts − except water extract in low concentration − reduced lipid oxidation during 10 wk of storage when added in a concentration of 0.5 or 1 g extract/100 g emulsion. Ethanol (EE) and acetone extracts (AE) (in the lowest concentration) were found to be most efficient as antioxidants in the bars. The antioxidant efficacy of these two extracts was among other related to an improved incorporation of the fish oil‐in‐water emulsions in the bars, high total phenolic content, high radical scavenging activity together with high interfacial affinity of phenolic compounds and probably regeneration of tocopherol.Practical applications: The work showed the application potential of F. vesiculosus extracts as a natural antioxidant in low‐moisture foods such as granola bars. These findings implied that the multi‐functional nature of these extracts provides not only oxidative stability of the food but also a physical stability.Granola bars enriched with 10% Sodium caseinate (Na‐Cas) fish oil‐in‐water emulsion where Fucus vesiculosus extracts where added as antioxidant to control lipid oxidation. Development of secondary oxidation product, 1‐penten‐3‐ol (ng/g granola bar) in the granola bars and confocal light scattering microscopic images of granola bar added 0.5 g acetone extract/100g emulsion (AE1) and the Control (Con) (without extract). The efficacy of acetone extracts to limit development of 1‐penten‐3‐ol in granola bars was found to be related to extract composition as well as the microstructure, as fish oil emulsions in the bars were more stable when this extract was added. Error bars indicate SD of the measurements (n = 3).