Seaweed fermentation within the fields of food and natural products

Fermentation of Pyropia spp. seaweed: a comprehensive review on processing conditions, biological activities and potential applications in the food industry

Pyropia spp. seaweeds are delicious and nutritious red algae widely consumed for a long history. However, due to the non-digestibility of cell wall components by the human intestinal tract, the bioaccessibility of the intracellular bioactive compounds is low. The current industrial processing of Pyropia spp. food by drying and roasting cannot break down the cell wall; however, studies indicate that fermentation of Pyropia spp. by food-derived microorganisms is an efficient processing method to solve this problem. This paper reviews research on the fermentation of Pyropia spp., including the manufacturing process, alterations in chemical composition, flavor properties, bioactivities, and mechanisms. Furthermore, the limitations and opportunities for developing Pyropia spp. fermentation food are explored. Studies demonstrated that key metabolites of fermented Pyropia spp. were degraded polysaccharides, released phenolic compounds and flavonoids, and formed amino acids, which possessed bioactivities such as antioxidant, anti-glycation, anti-diabetic, lipid metabolism regulation beneficial to human health. The increased bioactivities implied the promoted bioaccessibility of intracellular components. Notably, fermentation positively contributed to the safety of Pyropia spp. food. In conclusion, benefits in nutrition, flavor, bioactivity, and safety suggest that fermentation technology has a promising future for application in Pyropia spp. food industry.

Identification and validation of core microbes for the formation of the characteristic flavor of fermented oysters (Crassostrea gigas)

Self-fermented oyster homogenates were prepared to investigate core microbes and their correlations with flavor formation mechanisms. Five bacterial and four fungal genera were identified. Correlation analysis showed that Saccharomyces cerevisiae, Kazachstania, and L. pentosus were core species for the flavor of fermented products. Four core microbes were selected for inoculation into homogenates. Twelve key aroma compounds with odor activity values >1 were identified by gas chromatography-mass spectrometry. L. plantarum and S. cerevisiae were beneficial for producing key aroma compounds such as 1-octen-3-ol, (E,Z)-2,6-nonadienal, and heptanal. Fermentation with four microbes resulted in significant increases in contents of Asp, Glu, Lys, inosine monophosphate, and guanosine monophosphate, which provided freshness and sweetness. Fermentation with four microbes resulted in high digestibility, antioxidant abilities, and zinc contents. This study has elucidated the mechanism of flavor formation by microbial action and provides a reference for targeted flavor control in fermented oyster products.

Comprehensive Nutritional and Functional Characterization of Novel Mycoprotein Derived from the Bioconversion of Durvillaea spp

This study aimed, for the first time, to determine the nutritional composition, beta-glucan and ergosterol contents, phenolic compound composition, and biological and functional activities of a novel mycoprotein produced through a bioconversion process of Durvillaea spp., a brown seaweed. An untargeted metabolomics approach was employed to screen metabolites and annotate molecules with nutraceutical properties. Two products, each representing a distinct consortia of co-cultured fungi, named Myco 1 and Myco 2, were analysed in this study. These consortia demonstrated superior properties compared to those of Durvillaea spp., showing significant increases in total protein (~238%), amino acids (~219%), and β-D-glucans (~112%). The protein contains all essential amino acids, a low fatty acid content, and exhibits high antioxidant activity (21.5-25.5 µmol TE/g). Additionally, Myco 2 exhibited the highest anti-alpha-glucosidase activity (IC50 = 16.5 mg/mL), and Myco 1 exhibited notable anti-lipase activity (IC50 = 10.5 mg/mL). Among the 69 top differentially abundant metabolites screened, 8 nutraceutical compounds were present in relatively high concentrations among the identified mycoproteins. The proteins and polysaccharides in the mycoprotein may play a crucial role in the formation and stabilization of emulsions, identifying it as a potent bioemulsifier. In conclusion, the bioconversion of Durvillaea spp. results in a mycoprotein with high-quality protein, significant nutritional and functional value, and prebiotic and nutraceutical potential due to the production of unique bioactive compounds.

The green seaweed Ulva: tomorrow's "wheat of the sea" in foods, feeds, nutrition, and biomaterials

Ulva, a genus of green macroalgae commonly known as sea lettuce, has long been recognized for its nutritional benefits for food and feed. As the demand for sustainable food and feed sources continues to grow, so does the interest in alternative, plant-based protein sources. With its abundance along coastal waters and high protein content, Ulva spp. have emerged as promising candidates. While the use of Ulva in food and feed has its challenges, the utilization of Ulva in other industries, including in biomaterials, biostimulants, and biorefineries, has been growing. This review aims to provide a comprehensive overview of the current status, challenges and opportunities associated with using Ulva in food, feed, and beyond. Drawing on the expertise of leading researchers and industry professionals, it explores the latest knowledge on Ulva's nutritional value, processing methods, and potential benefits for human nutrition, aquaculture feeds, terrestrial feeds, biomaterials, biostimulants and biorefineries. In addition, it examines the economic feasibility of incorporating Ulva into aquafeed. Through its comprehensive and insightful analysis, including a critical review of the challenges and future research needs, this review will be a valuable resource for anyone interested in sustainable aquaculture and Ulva's role in food, feed, biomaterials, biostimulants and beyond.

Extraction of Protein and Bioactive Compounds from Mediterranean Red Algae (Sphaerococcus coronopifolius and Gelidium spinosum) Using Various Innovative Pretreatment Strategies

In this study, the release of proteins and other biomolecules into an aqueous media from two red macroalgae (Sphaerococcus coronopifolius and Gelidium spinosum) was studied using eight different cell disruption techniques. The contents of carbohydrates, pigments, and phenolic compounds coextracted with proteins were quantified. In addition, morphological changes at the cellular level in response to the different pretreatment methods were observed by an optical microscope. Finally, the antioxidant capacity of obtained protein extracts was evaluated using three in vitro tests. For both S. coronopifolius and G. spinosum, ultrasonication for 60 min proved to be the most effective technique for protein extraction, yielding values of 3.46 ± 0.06 mg/g DW and 9.73 ± 0.41 mg/g DW, respectively. Furthermore, the highest total contents of phenolic compounds, flavonoids, and carbohydrates were also recorded with the same method. However, the highest pigment contents were found with ultrasonication for 15 min. Interestingly, relatively high antioxidant activities like radical scavenging activity (31.57-65.16%), reducing power (0.51-1.70, OD at 700 nm), and ferrous iron-chelating activity (28.76-61.37%) were exerted by the different protein extracts whatever the pretreatment method applied. This antioxidant potency could be attributed to the presence of polyphenolic compounds, pigments, and/or other bioactive substances in these extracts. Among all the used techniques, ultrasonication pretreatment for 60 min appears to be the most efficient method in terms of destroying the macroalgae cell wall and extracting the molecules of interest, especially proteins. The protein fractions derived from the two red macroalgae under these conditions were precipitated with ammonium sulfate, lyophilized, and their molecular weight distribution was determined using SDS-PAGE. Our results showed that the major protein bands were observed between 25 kDa and 60 kDa for S. coronopifolius and ranged from 20 kDa to 150 kDa for G. spinosum. These findings indicated that ultrasonication for 60 min could be sufficient to disrupt the algae cells for obtaining protein-rich extracts with promising biological properties, especially antioxidant activity.

Protective Effect of Sargassum fusiforme Fucoidan against Ethanol-Induced Oxidative Damage in In Vitro and In Vivo Models

Our previous studies have evaluated the bioactivities of a fucoidan isolated from Sargassum fusiforme (SF-F). To further investigate the health benefit of SF-F, in the present study, the protective effect of SF-F against ethanol (EtOH)-induced oxidative damage has been evaluated in in vitro and in vivo models. SF-F effectively improved the viability of EtOH-treated Chang liver cells by suppressing apoptosis. In addition, the in vivo test results indicate that SF-F significantly and dose-dependently increased the survival rate of zebrafish treated with EtOH. Further research results show that this action works through decreasing cell death via reduced lipid peroxidation by scavenging intracellular reactive oxygen species in EtOH-stimulated zebrafish. These results indicate that SF-F effectively protected Chang liver cells and zebrafish against EtOH-induced oxidative damage and suggest the potential of SF-F to be used as an ingredient in the functional food industry.

Biomolecules from Macroalgae-Nutritional Profile and Bioactives for Novel Food Product Development

Seaweed is in the spotlight as a promising source of nutrition for humans as the search for sustainable food production systems continues. Seaweed has a well-documented rich nutritional profile containing compounds such as polyphenols, carotenoids and polysaccharides as well as proteins, fatty acids and minerals. Seaweed processing for the extraction of functional ingredients such as alginate, agar, and carrageenan is well-established. Novel pretreatments such as ultrasound assisted extraction or high-pressure processing can be incorporated to more efficiently extract these targeted ingredients. The scope of products that can be created using seaweed are wide ranging: from bread and noodles to yoghurt and milk and even as an ingredient to enhance the nutritional profile and stability of meat products. There are opportunities for food producers in this area to develop novel food products using seaweed. This review paper discusses the unique properties of seaweed as a food, the processes involved in seaweed aquaculture, and the products that can be developed from this marine biomass. Challenges facing the industry such as consumer hesitation around seaweed products, the safety of seaweed, and processing hurdles will also be discussed.

Prospects of dietary seaweeds and their bioactive compounds in sustainable poultry production systems: A symphony of good things?

Modern poultry production systems face numerous economic, environmental, and social sustainability challenges that threaten their viability and acceptability as a major source of animal protein. As scientists and producers scramble to find cost-effective and socially acceptable solutions to these challenges, the dietary use of marine macroalgae (seaweeds) could be an ingenious option. Indeed, the incredible array of nutritive and bioactive compounds present in these macroscopic marine organisms can be exploited as part of sustainable poultry production systems of the future. Incorporating seaweeds in poultry diets could enhance feed utilization efficiency, growth performance, bird health, meat stability and quality, and consumer and environmental health. Theoretically, these benefits are mediated through the putative antiviral, antibacterial, antifungal, antioxidant, anticarcinogenic, anti-inflammatory, anti-allergic, antithrombotic, neuroprotective, hypocholesterolemic, and hypoglycemic properties of seaweed bioactive compounds. Despite this huge potential, exploitation of seaweed for poultry production appears to be constrained by a variety of factors such as high fibre, phenolics, and ash content. In addition, conflicting findings are often reported when seaweeds or their extracts are used in poultry feeding trials. Therefore, the purpose of this review paper is to collate information on the production, phytochemical components, and nutritive value of different seaweed species. It provides an overview ofin vivoeffects of dietary seaweeds as measured by nutrient utilization efficiency, growth performance, and product quality and stability in poultry. The utility of dietary seaweeds in sustainable poultry production systems is explored, while gaps that require further research are highlighted. Finally, opportunities that exist for enhancing the utility of seaweeds as a vehicle for sustainable production of functional poultry products for better global food and nutrition security are presented.

The fourth industrial revolution in the food industry-part II: Emerging food trends

The food industry has recently been under unprecedented pressure due to major global challenges, such as climate change, exponential increase in world population and urbanization, and the worldwide spread of new diseases and pandemics, such as the COVID-19. The fourth industrial revolution (Industry 4.0) has been gaining momentum since 2015 and has revolutionized the way in which food is produced, transported, stored, perceived, and consumed worldwide, leading to the emergence of new food trends. After reviewing Industry 4.0 technologies (e.g. artificial intelligence, smart sensors, robotics, blockchain, and the Internet of Things) in Part I of this work (Hassoun, Aït-Kaddour, et al. 2022. The fourth industrial revolution in the food industry-Part I: Industry 4.0 technologies. Critical Reviews in Food Science and Nutrition, 1-17.), this complimentary review will focus on emerging food trends (such as fortified and functional foods, additive manufacturing technologies, cultured meat, precision fermentation, and personalized food) and their connection with Industry 4.0 innovations. Implementation of new food trends has been associated with recent advances in Industry 4.0 technologies, enabling a range of new possibilities. The results show several positive food trends that reflect increased awareness of food chain actors of the food-related health and environmental impacts of food systems. Emergence of other food trends and higher consumer interest and engagement in the transition toward sustainable food development and innovative green strategies are expected in the future.