valorization-red-seaweed-gracilaria-gracilis-through-biorefinery

Valorization of the Red Seaweed <em>Gracilaria gracilis</em> Through a Biorefinery Approach

The interest in seaweeds as an abundant feedstock to obtain valuable and multitarget bioactive ingredients is continuously growing. In this work, we ...

Due to the current demand for healthier food, the IV gamma products industry has grown over the years. Additionally, it is well known that chlorine is a disinfectant largely used in this industry. However, the risk assessment associated with the formation of carcinogenic by-products from this halogenated disinfection has not been widely studied. The aim of this study was to assess the trihalomethanes (THMs) exposure through the consumption of IV gamma products, more specifically, salad mixes, and potential health risk in Portuguese population using a deterministic method. The quantification of THMs in salad mixes from the most representative Portuguese brands was performed by gas chromatography coupled to mass spectrometry (GC-MS). The THMs exposures were estimated by combining the THMs concentration data with a ready-to-eat salad mix consumption survey (case study applied in the Lisboa e Vale do Tejo area; n = 271). The concentration of THMs in all samples was below the limit of quantification of the equipment (1 μg/L), and this limit was used for the evaluation of the exposure. It was found that it is very small for the consumption pattern of these products in the studied population categories, suggesting that there is no risk for consumers due to the halogenated disinfection process. The highest estimated daily exposure was 7,6510 mg/ kg bw/ week, which corresponds to a person who consumes such products daily.

Risk assessment of trihalomethanes exposure by consumption of IV gamma products: Evidences from a Portuguese regional survey.

The extraction of phycobiliprotein (PBP) pigments from red algae Gracilaria gracilis was optimized using maceration, ultrasound-assisted extraction (ultrasonic water bath and ultrasonic probe), high pressure-assisted extraction, and freeze-thaw. The experimental conditions, namely homogenization time (t1), buffer concentration (C), treatment time (t2), biomass: buffer ratio (R), and pressure (P), were optimized using Response Surface Methodology (RSM). The yield of phycoerythrin (PE) extracted, determined spectroscopically, was used as the response variable. Maceration was the most efficient extraction method yielding 3.6 mg PE/g biomass under the optimal conditions (t1 = t2 = 10 min; C = 0.1 M; R = 1:50). Scanning Electron Microscopy (SEM) analysis of the biomass before and after the cell disruption treatments revealed a more efficient cell wall rupture with maceration.

Optimization of phycobiliprotein pigments extraction from red algae Gracilaria gracilis for substitution of synthetic food colorants.

 is an edible brown seaweed (SW) found in the Portuguese Coast. It has been reported to have high antioxidant activity, which may elicit a potential use for the food industry. However, little information is available on how the SW behaves during the digestive process and how the freeze-drying process might affect the bioaccessibility of the different compounds. Therefore, antioxidant activity, total polyphenols, lipid, and fatty acid contents were measured before and after in vitro simulation of the human digestive process, both in fresh and freeze-dry SW.  had a lipid content of 3.49 ± 0.3% of dry weight (DW), which is a usual amount described for this SW genus. The total lipid bioaccessibility was 12.1 ± 0.1%. The major omega-3 fatty acid detected was eicosapentaenoic acid, 7.5 ± 0.1%, with a bioaccessibility percentage of 13.0 ± 1.0%. Four different methods-total phenolic content (TPC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and 1,1-diphenyl-2-picryl-hydrazyl (DPPH)-were used to assess the antioxidant activity of . The bioaccessibility of the antioxidants studied, ranged between 42.7% and 59.5%, except the bioaccessibility of polyphenols in freeze-dried SW (23.0% ± 1.0%), suggesting that the freeze-drying process reduces the bioaccessibility of these compounds.

Bioaccessibility of Antioxidants and Fatty Acids from .

Phycobiliprotein (PBP) pigments were extracted from red algae Gracilaria gracilis through maceration in phosphate buffer using previously optimized conditions. The stability of PBPs in the extracts was assessed by monitoring the extracts at different pHs and temperatures for 10 days. Since phycoerythrin (PE) is the main PBP present in G. gracilis, PE content was spectroscopically determined and used as a response factor. Kinetic modeling was used to describe PE degradation under different ranges of T and pH. The pigment extracts presented higher stability at pH 6.9 and -20 °C. PE was semipurified by precipitation with ammonium sulphate 65% followed by dialysis against water until a purity index of 0.7. The pigment was successfully applied as colorant in pancakes and yogurts with a pigment concentration of 0.15%. This study highlights the potential of PE pigments extracted from G. gracilis for applications in food products. PRACTICAL APPLICATION: Phycobiliprotein pigments were extracted from red algae Gracilaria gracilis through maceration in phosphate buffer. The stability of the pigment was evaluated at different pHs and temperatures, presenting higher stability at neutral pH and low temperatures. The pigment was successfully applied as colorant in pancakes and yogurts with a low pigment concentration. This study highlights the potential of phycobiliprotein pigments extracted from G. gracilis for applications in food products.

Stability, kinetics, and application study of phycobiliprotein pigments extracted from red algae Gracilaria gracilis.

Fish is a very perishable food and therefore several storage strategies need to be employed to increase its shelf-life, guaranteeing its safety and quality from catch to consumption. Despite the advances in modern fish storage technologies, chilling and freezing are still the most common preservation methods used onboard. The present review aims to summarize strategies to increase the shelf-life of fresh (chilled) and frozen fish, as whole, gutted, or fillet, involving the assessment of different traditional cooling and freezing conditions of different fish species caught in different locations. Although there are other factors that influence the fish shelf-life, such as the fish species and the stress suffered during catch, storage time and temperature and the amount of ice are some of the most important. In addition, the way that fish is stored (whole, fillet, or gutted) also contributes to the final quality of the product. In most studies, whole chilled and frozen fish present longer shelf-life than those preserved as gutted and filleted. However, it should be noted that other factors related to the organism, capture method, and transport to the preparation/processing industry should be considered for shelf-life extension.

Quality Assessment of Chilled and Frozen Fish-Mini Review.

Overfishing is increasing over time, and according to FAO (Food and Agriculture Organization), about one third of the world's fish stocks are now overfished. Thus, diversifying the target species is essential for fisheries sustainability contributing to improve resource-efficient processes. Non-target species can be valuable resources for the development of new food products. However, those species are scarcely studied, and it is of high importance to trace their seasonal sensory profile as a first step towards their valorisation. Therefore, in this study, seasonal influence on sensory properties of five low commercial value or unexploited fish species, namely  (blue jack mackerel),  (black seabream),  (piper gurnard),  (comber) and  (boarfish), was assessed in order to identify the most favourable season for catching each species. Fish samples were assessed by a panel of 16 semi-trained assessors for sensory attributes previously identified. The evaluation takes place every 2 months. Statistical differences were reported between attributes and seasons for all species, except for , which did not present any difference in its sensory attributes throughout the year.

Seasonal Sensory Evaluation of Low Commercial Value or Unexploited Fish Species from the Portuguese Coast.

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, ; black seabream, ; and piper gurnard, ) and of two unexploited species (comber,  and boarfish, ) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream , smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream  (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.

Adding Value to Bycatch Fish Species Captured in the Portuguese Coast-Development of New Food Products.

An important factor in consumers' acceptability, beyond visual appearance and taste, is food texture. The elderly and people with dysphagia are more likely to present malnourishment due to visually and texturally unappealing food. Three-dimensional Printing is an additive manufacturing technology that can aid the food industry in developing novel and more complex food products and has the potential to produce tailored foods for specific needs. As a technology that builds food products layer by layer, 3D Printing can present a new methodology to design realistic food textures by the precise placement of texturing elements in the food, printing of multi-material products, and design of complex internal structures. This paper intends to review the existing work on 3D food printing and discuss the recent developments concerning food texture design. Advantages and limitations of 3D Printing in the food industry, the material-based printability and model-based texture, and the future trends in 3D Printing, including numerical simulations, incorporation of cooking technology to the printing, and 4D modifications are discussed. Key challenges for the mainstream adoption of 3D Printing are also elaborated on.

Food Texture Design by 3D Printing: A Review.

The depletion and overexploitation of several fish stock demands for a valorisation of non-target and discarded species. Nonetheless, such species are often poorly studied, and information on their biological parameters must be gathered for effective population management. For 1 year, the reproductive strategy of the piper gurnard Trigla lyra and the red gurnard Chelidonichthys cuculus was studied by monthly samples obtained from commercial boats operating on western Portuguese coast. Both species showed a biased sex ratio towards females, especially for larger length classes. Length at first maturity could be estimated only for red gurnard (22.1 and 19.9 cm for females and males, respectively) because all piper gurnard individuals caught were mature. Piper gurnard showed determinate fecundity and a short spawning season, from November to February with a peak in January, whereas red gurnard showed indeterminate fecundity and a wide spawning season, from late December to May. The relative annual fecundity estimated for red gurnard (1893 ± 728 oocytes × g eviscerated weight [EW]) was higher than the one estimated for piper gurnard (1018 ± 250 oocytes×g EW). Although important information for understanding the species dynamics is presented in this study, additional information on other life-history parameters and of species landings is required.

Enhancing knowledge on low-value fishing species: the distinct reproductive strategy of two gurnard species.

 that was collected in the four seasons was submitted to an extraction with ethanol:water (crude extracts Et80), followed by a liquid-liquid fractionation with organic solvents (fraction He from n-hexane; aqueous fractions AQ1, AQ2, AQ3 and AQ4; ethyl acetate fraction EA), with the aim of obtaining phlorotannin-enriched extracts. All the extracts (Et80, He, AQ1, AQ2, AQ3, AQ4 and EA) that were obtained for the  of the four seasons were evaluated for their antioxidant capacity and total phenolic compounds. The summer extracts presented the highest contents in polyphenols (TPC), as well as the highest ferric reducing antioxidant power (FRAP), when compared to the samples from the other seasons. The reductive percentage of the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) compound was similar between the seasons. For all the seasons, the EA extract showed the highest polyphenol content (TPC), and the highest antioxidant capacity (highest ferric reducing power (FRAP) and lowest concentration needed to reduce 50% of the DPPH compound), which is in agreement with a phlorotannin-enriched fraction. This study revealed that the polyphenol content and antioxidant power of the  extracts are influenced by the time of harvest, as well as by the solvents used for their extraction.

Seasonal Evaluation of Phlorotannin-Enriched Extracts from Brown Macroalgae .

Due to the high consumption of fat-rich processed foods, efforts are being done to reduce their saturated fat (SFA) contents and replace it with polyunsaturated fatty acids (PUFA), creating a necessity to find alternative PUFA sources. Macroalgae, being a promising natural source of healthy food, may be such an alternative. The fatty acid (FA) profile of , , , and  were determined through direct transesterification and their seasonal variation was studied.  showed the highest FA content overall,  presented the higher PUFA amounts, and  and  the higher SFA. The production of FA was shown to be influenced by the seasons. Spring and summer seemed to induce the FA production in  and  while in  the same was verified in winter.  presented a ω6/ω3 ratio between 0.59 and 1.38 while  presented a ratio around 1.31. The study on the seasonal variations of the macroalgal FA profile can be helpful to understand the best season to yield FA of interest, such as ALA, EPA, and DHA. It may also provide valuable information on the best culturing conditions for the production of desired FAs.

Study of the Seasonal Variations of the Fatty Acid Profiles of Selected Macroalgae.

Due to its characteristics, fresh fish is a highly perishable food with a very short shelf-life under refrigeration. Several methods have been introduced to slow down its deterioration, such as by means of oxygen depletion of the food package (vacuum packaging), or by changing the natural atmosphere that is in contact with the fresh fish (modified atmosphere packaging), or by the use of chemicals generally recognized as safe: such compounds can be directly applied (by dipping or spraying) or incorporated into packaging materials and slowly migrate to the product, exerting a hurdle effect against microbial development and lipid oxidation (active packaging). This review aims to cover the most recent advances in chemical-based approaches for fresh fish preservation, applied either singly or in combination. Vacuum packaging, modified atmosphere, and active packaging preservation methodologies are presented, along with the inclusion of chemical additives, such as organic acids and natural extracts, and their combination with icing systems. Advantages and disadvantages of these methodologies and their impact on fresh fish quality and shelf-life are discussed, reaching the conclusion that both are positively influenced overall. Indeed, the contribution of chemical-based strategies for fresh fish preservation is undeniable, and is expected to be a research topic of increasing interest in the future.

Chemical-Based Methodologies to Extend the Shelf Life of Fresh Fish-A Review.

The most consumed fish species in Portugal do not correspond to the most caught fish species on the Portuguese coast. From the point of view of ocean sustainability and economics, it is important to study unexploited or underexploited fish species that have the potential to be introduced into the food market. This potential can be reflected by their nutritional value, where mineral elements are often overlooked despite their importance in human health. Therefore, it is important to study the elemental concentration of those fish species, which should also include seasonal variations of essential mineral elements such as Ca, P, Mg, Na, K, Fe, Cu, Mn, Zn, and I, and non-essential elements such as As, Ni, Cd, and Pb. This work is part of a project that studied five fish species with the potential to be brought to the market: three species with low commercial value (Trachurus picturatus, Spondyliosoma cantharus and Trigla lyra) and two species with no commercial value (Serranus cabrilla and Capros aper), caught over a year in the coast of Portugal. Mineral elements were quantified by ICP-OES (ICP-MS for I). The results showed that the studied fish species present significant elemental concentrations, similar to those found in the most caught fish species in Portugal. Trachurus picturatus was found to be a source of Fe, and all species are sources of I. Overall, Spondyliosoma cantharus proved to be the most element-rich species. Sensorially, Cu was related to "metallic odour" and Fe to "metallic flavour", and I was related to "seaweed odour" and "seawater flavour". Additionally, toxic elements such as Cd, Pb, Ni and As were not detected. The corresponding Hazard Quotients (HQ) show the safety of the consumption of these fish species concerning the content of potentially toxic elements.

Annual variations in the mineral element content of five fish species from the Portuguese coast.

Target species diversification is essential for fisheries sustainability and fish market revitalization. Fish discards are a widely recognized problem resulting from fisheries worldwide, and are of major concern for all sector players, from administrations, to fishermen, and scientists. However, non-target species are seldom studied, and information on nutritional profiles and seasonal changes in nutritional properties is generally lacking. This study assessed the seasonal nutritional composition of two unexploited (, ) and three low commercial value fish species (, , and ), captured on the Portuguese coast over 1 year. Significant seasonal variations were observed in the nutritional composition of all the species studied. Moisture and ash contents varied from 70% to 81% and from 5% to 13%, respectively. The maximum fat contents were 5% for  and 4% for , allowing to classify all studied fishes as lean. The highest protein contents were recorded for  (25%) and  (20%). The unexploited and low commercial value fish species studied were shown to be good fat and protein sources, comparable to commonly consumed species, such as cod and salmon, having a great potential to become commonly consumed fish in Portugal.

Seasonal study of the nutritional composition of unexploited and low commercial value fish species from the Portuguese coast.

Blue jack mackerel, , is the fifth most landed fish species in mainland Portugal, but information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens were collected from commercial vessels to clarify the reproductive strategy of the  population off the west coast of Portugal. The proportion and length range of males and females were similar. Only three of the specimens collected were categorized as immature, indicating that the fish caught in the fishery are primarily mature. The spawning season lasted from late January until the end of March, with gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low number of females showing direct evidence of imminent or recent spawning suggests a low number of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary abnormalities including parasitic infection by  species, atretic structures and skipped spawning events. This study highlights the importance of accounting for skipped spawning events and ovary abnormalities in the management of species fisheries.

Reproduction of the Blue Jack Mackerel, , in Western Portugal: Microscopic Gonad Analysis Reveals Indeterminate Fecundity and Skipped Spawning Patterns.

Article	Year
Risk assessment of trihalomethanes exposure by consumption of IV gamma products: Evidences from a Portuguese regional survey. Toxicology reports\| PubMed ID: 32071882	2020
Optimization of phycobiliprotein pigments extraction from red algae Gracilaria gracilis for substitution of synthetic food colorants. Food chemistry\| PubMed ID: 32247888	2020
Bioaccessibility of Antioxidants and Fatty Acids from . Foods (Basel, Switzerland)\| PubMed ID: 32268534	2020
Stability, kinetics, and application study of phycobiliprotein pigments extracted from red algae Gracilaria gracilis. Journal of food science\| PubMed ID: 32885442	2020
Quality Assessment of Chilled and Frozen Fish-Mini Review. Foods (Basel, Switzerland)\| PubMed ID: 33255842	2020
Seasonal Sensory Evaluation of Low Commercial Value or Unexploited Fish Species from the Portuguese Coast. Foods (Basel, Switzerland)\| PubMed ID: 33348717	2020
Adding Value to Bycatch Fish Species Captured in the Portuguese Coast-Development of New Food Products. Foods (Basel, Switzerland)\| PubMed ID: 33396392	2020
Food Texture Design by 3D Printing: A Review. Foods (Basel, Switzerland)\| PubMed ID: 33546337	2021
Enhancing knowledge on low-value fishing species: the distinct reproductive strategy of two gurnard species. Journal of fish biology\| PubMed ID: 34254304	2021
Seasonal Evaluation of Phlorotannin-Enriched Extracts from Brown Macroalgae . Molecules (Basel, Switzerland)\| PubMed ID: 34299561	2021
Study of the Seasonal Variations of the Fatty Acid Profiles of Selected Macroalgae. Molecules (Basel, Switzerland)\| PubMed ID: 34641350	2021
Chemical-Based Methodologies to Extend the Shelf Life of Fresh Fish-A Review. Foods (Basel, Switzerland)\| PubMed ID: 34681354	2021
Annual variations in the mineral element content of five fish species from the Portuguese coast. Food research international (Ottawa, Ont.)\| PubMed ID: 35840200	2022
Seasonal study of the nutritional composition of unexploited and low commercial value fish species from the Portuguese coast. Food science & nutrition\| PubMed ID: 36249977	2022
Reproduction of the Blue Jack Mackerel, , in Western Portugal: Microscopic Gonad Analysis Reveals Indeterminate Fecundity and Skipped Spawning Patterns. Zoological studies\| PubMed ID: 36568809	2022

Maria M Gil

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