Seaweeds as Novel Foods and Source of Culinary Flavors

Seaweeds-derived proteins and peptides: preparation, virtual screening, health-promoting effects, and industry applications

Seaweed, a promising source of nutritional proteins, including protein hydrolysates, bioactive peptides, phycobiliproteins, and lectins with multi-biological activities. Seaweeds-derived proteins and peptides have attracted increasing interest for their potential applications in dietary supplements, functional foods, and pharmaceuticals industries. This work aims to comprehensively review the preparation methods and virtual screening strategies for seaweed-derived functional peptides. Additionally, it elucidates their diverse biological activities, mechanisms of action, and industrial applications. Enzymatic hydrolysis appears as the most effective method for preparing functional peptides from seaweeds. Computational virtual screening has also proven to be a valuable strategy for assessing the nature of the peptides. Seaweeds-derived proteins and peptides offer numerous health benefits, including alleviation of oxidative stress, anti-diabetic, anti-hypertensive, anti-inflammatory, anti-obesity, anti-cancer, and anti-microbial activities. Studies indicate that proteins hydrolysates and peptides derived from seaweeds with low molecular weight and aromatic and/or hydrophobic amino acids are particularly significant in contributing to these diverse bio-activities. Furthermore, seaweeds-derived proteins and peptides hold great promise for industrial applications owing to the broad spectrum of bio-functional effects. They can be used as active ingredients in food products or pharmaceuticals for disease prevention and treatment, and as food preservatives, potentially with fewer side effects.

Metabolomic analysis of umami taste variation in Pyropia haitanensis throughout the harvest cycle

Porphyra sensu lato, a highly valuable edible seaweed renowned for its distinctive umami taste, undergoes significant taste variations during the harvest cycle, affecting product quality and pricing. In this study, umami-related metabolites in Pyropia haitanensis were investigated at different harvesting times using GC-MS metabolomic, targeted LC-MS analysis, and an electronic tongue taste evaluation. High concentrations of compounds, including glutamic acid, aspartic acid, and inosine 5'-monophosphate, were identified as the main contributors to the overall umami profile. The concentrations of the compounds and umami-enhancing substances, such as sugars, were negatively correlated as the harvesting period extended. The early harvested P. haitanensis exhibited a superior umami taste, which gradually decreased with subsequent harvest time. Proline, a known cold-resistance metabolite, accumulated as the seawater temperature decreased and the harvest period progressed. These findings provide insights into the optimal cultivation and harvesting practices for maintaining umami quality in P. haitanensis products.

Innovative strategies for protein content determination in dried laver (Porphyra spp.): Evaluation of preprocessing methods and machine learning algorithms through short-wave infrared imaging

In this study, we explored the application of Short-Wave Infrared (SWIR) hyperspectral imaging combined with Competitive Adaptive Reweighted Sampling (CARS) and advanced regression models for the non-destructive assessment of protein content in dried laver. Utilizing a spectral range of 900-1700 nm, we aimed to refine the quality control process by selecting informative wavelengths through CARS and applying various preprocessing techniques (standard normal variate [SNV], Savitzky-Golay filtering [SG], Orthogonal Signal Correction [OSC], and StandardScaler [SS]) to enhance the model's accuracy. The SNV-OSC-StandardScaler- Support vector regression (SVR) model trained on CARS-selected wavelengths significantly outperformed the other configurations, achieving a prediction determination coefficient (Rp2) of 0.9673, root mean square error of prediction of 0.4043, and residual predictive deviation of 5.533. These results highlight SWIR hyperspectral imaging's potential as a rapid and precise tool for assessing dried laver quality, aiding food industry quality control and dried laver market growth.

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.

Nitrate, Nitrite, and Iodine Concentrations in Commercial Edible Algae: An Observational Study

Edible algae are a natural source of nutrients, including iodine, and can also contain nitrogen in the form of nitrate (NO3-) and nitrite (NO2-) as they can fix nitrogen from seawater. This study aimed to analyse the NO3-, NO2-, and iodine concentrations in eighteen macroalgae and five microalgae species commercially available in the United Kingdom. NO3- and NO2- concentrations were measured using high-performance liquid chromatography (HPLC), and iodine was determined using inductively coupled plasma mass spectrometry (ICP-MS). NO3- and iodine concentrations in macroalgae (NO3-: 4050.13 ± 1925.01 mg/kg; iodine: 1925.01 ± 1455.80 mg/kg) were significantly higher than in microalgae species (NO3-: 55.73 ± 93.69 mg/kg; iodine: 17.61 ± 34.87 mg/kg; p < 0.001 for both). In the macroalgae group, nori had the highest NO3- (17,191.33 ± 980.89 mg/kg) and NO2- (3.64 ± 2.38 mg/kg) content, as well as the highest iodine content. Among microalgae, Dunaliella salina had the highest concentration of NO3- (223.00 ± 21.93 mg/kg) and iodine (79.97 ± 0.76 mg/kg), while Spirulina had the highest concentration of NO2- (7.02 ± 0.13 mg/kg). These results indicate that commercially available edible algae, particularly macroalgae species, could be a relevant dietary source of NO3- and iodine.

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.

Brine-Processed Caulerpa lentillifera Macroalgal Stability: Physicochemical, Nutritional and Microbiological Properties

Caulerpa lentillifera is a type of green macroalga that is commonly consumed as fresh seaweed, particularly in Southeast Asia. The effects of different salt types and concentrations on C. lentillifera during brine processing were investigated using table, sea and flower salt at 10-30% levels. The colour and texture of C. lentillifera varied across different treatments. After storage in brine for 12 weeks, lightness (L*) decreased, greenness (a*) decreased and yellowness (b*) increased while firmness increased in all treatments compared to fresh algae. The nutritional composition did not change significantly over time. To ensure the safety and quality of seaweed for consumption, the optimal salt level for brine processing should not exceed 30% table salt. The morphology and elements contained in different types of salt were also observed, and the microbiological safety of seaweed was evaluated. The popularity of Caulerpa macroalgae is rapidly increasing among consumers, leading to a growing demand for ready-to-eat Caulerpa products. However, food safety and security standards must be maintained.

A review of volatile compounds in edible macroalgae

Seaweeds (green algae, red algae and brown algae) are rich in nutrients, and incorporating algae into the human diet can provide important health benefits. However, consumer acceptance of food is closely related to its flavor, and in this respect, volatile compounds are key factors. This article reviews the extraction methods and composition of volatile compounds from Ulva prolifera, Ulva lactuca, Sargassum spp. and economically valuable cultured seaweeds such as Undaria pinnatifida, Laminaria japonica, Neopyropia haitanensis and Neopyropia yezoensis. Research found that the volatile compounds of the above seaweeds were composed mainly of aldehydes, ketones, alcohols, hydrocarbons, esters, acids, sulfur compounds, furans and small amounts of other compounds. Volatile compounds such as benzaldehyde, 2-octenal, octanal, β-ionone and 8-heptadecene have been identified in several macroalgae. This review argues that more research on the volatile flavor compounds of edible macroalgae is required. Such research could aid new product development or widen applications of these seaweeds in the food or beverage sectors.

Sensory descriptors for three edible Chilean seaweeds and their relations to umami components and instrumental texture

Although seaweeds exhibit many benefits as a food source, few studies have characterized their sensory attributes. An expert nine-member panel developed a vocabulary with 25 descriptors to describe the appearance, aroma, flavor, texture, and aftertaste of raw and cooked seaweeds consumed in Chile: Durvillaea antarctica, Pyropia spp., and Ulva lactuca. Subsequently, the vocabulary was used in a ranking descriptive analysis (RDA) to evaluate the sensory properties and relate them with physicochemical and physical data. Sensory attributes of the three seaweeds were very different from each other but similar between treatments (raw and cooked). Pyropia spp., both cooked and hydrated, had the highest glutamate content (310 and 324 mg (100 g) ^-1 d.w., respectively), and was perceived by the sensory panel as having the most umami taste. Cooked D. antarctica was perceived as sweeter, had more caramel notes than the hydrated seaweed and was sensed as cartilaginous and hard in accordance with its mechanical properties. Generalized Procrustes analysis revealed that D. antarctica exhibited most of the desirable descriptors, such as caramel, umami and marine aromas while U. lactuca was described as bitter and moldy. This primary vocabulary can assist food scientists and chefs in the development of seaweed products and dishes for the consumer market.

Emerging Research Topics in the Vibrionaceae and the Squid-Vibrio Symbiosis

The Vibrionaceae encompasses a cosmopolitan group that is mostly aquatic and possesses tremendous metabolic and genetic diversity. Given the importance of this taxon, it deserves continued and deeper research in a multitude of areas. This review outlines emerging topics of interest within the Vibrionaceae. Moreover, previously understudied research areas are highlighted that merit further exploration, including affiliations with marine plants (seagrasses), microbial predators, intracellular niches, and resistance to heavy metal toxicity. Agarases, phototrophy, phage shock protein response, and microbial experimental evolution are also fields discussed. The squid-Vibrio symbiosis is a stellar model system, which can be a useful guiding light on deeper expeditions and voyages traversing these "seas of interest". Where appropriate, the squid-Vibrio mutualism is mentioned in how it has or could facilitate the illumination of these various subjects. Additional research is warranted on the topics specified herein, since they have critical relevance for biomedical science, pharmaceuticals, and health care. There are also practical applications in agriculture, zymology, food science, and culinary use. The tractability of microbial experimental evolution is explained. Examples are given of how microbial selection studies can be used to examine the roles of chance, contingency, and determinism (natural selection) in shaping Earth's natural history.

Fermented shellfish condiments: A comprehensive review

Fermented shellfish condiments are globally consumed especially among Asian countries. Condiments, commonly used as flavor enhancers, have unique sensory characteristics and are associated with umami and meaty aroma. The main reactions that occur during fermentation of shellfish include proteolysis by endogenous enzymes and microbial activities to produce peptides and amino acids. The actions of proteolytic enzymes and microorganisms (predominantly bacteria) are found to be largely responsible for the formation of taste and aroma compounds. This review elaborates different aspects of shellfish fermentation including classification, process, substrates, microbiota, changes in both physicochemical and biochemical components, alterations in nutritional composition, flavor characteristics and sensory profiles, and biological activities and their undesirable impacts on health. The characteristics of traditional shellfish production such as long duration and high salt concentration not only limit nutritional value but also inhibit the formation of toxic biogenic amines. In addition, this review article also covers novel bioprocesses such as low salt fermentation and use of novel starter cultures and/or novel enzymes to accelerate fermentation and produce shellfish condiments that are of better quality and safer for consumption. Practical Application: The review paper summarized the comprehensive information on shellfish fermentation to provide alternative strategies to produce shellfish comdiments that are of better quality and safer for consumption.

Truths and myths about superfoods in the era of the COVID-19 pandemic

Nowadays, during the current COVID-19 pandemic, consumers increasingly seek foods that not only fulfill the basic need (i.e., satisfying hunger) but also enhance human health and well-being. As a result, more attention has been given to some kinds of foods, termed "superfoods," making big claims about their richness in valuable nutrients and bioactive compounds as well as their capability to prevent illness, reinforcing the human immune system, and improve overall health.This review is an attempt to uncover truths and myths about superfoods by giving examples of the most popular foods (e.g., berries, pomegranates, watermelon, olive, green tea, several seeds and nuts, honey, salmon, and camel milk, among many others) that are commonly reported as having unique nutritional, nutraceutical, and functional characteristics.While superfoods have become a popular buzzword in blog articles and social media posts, scientific publications are still relatively marginal. The reviewed findings show that COVID-19 has become a significant driver for superfoods consumption. Food Industry 4.0 innovations have revolutionized many sectors of food technologies, including the manufacturing of functional foods, offering new opportunities to improve the sensory and nutritional quality of such foods. Although many food products have been considered superfoods and intensively sought by consumers, scientific evidence for their beneficial effectiveness and their "superpower" are yet to be provided. Therefore, more research and collaboration between researchers, industry, consumers, and policymakers are still needed to differentiate facts from marketing gimmicks and promote human health and nutrition.

Seaweeds as Ingredients to Lower Glycemic Potency of Cereal Foods Synergistically-A Perspective

Seaweeds are traditional food ingredients mainly in seaside regions. Modern food science and nutrition researchers have identified seaweed as a source of functional nutrients, such as dietary soluble and insoluble fibers, proteins, omega-3 fatty acids, prebiotic polysaccharides, polyphenols, and carotenoids. Owing to the rich nutrients, seaweeds and seaweed extract can be used as functional ingredients by modifying the nutrients composition to reduce the proportion of available carbohydrates, delaying the gastric emptying time and the absorption rate of glucose by increasing the digesta viscosity, and attenuating the digesting rate by blocking the activity of digestive enzymes. This review presents the concept of using seaweed as unconventional ingredients that can function synergistically to reduce the glycemic potency of cereal products.

Present and Future of Seaweed Cultivation and Its Applications in Colombia

Colombia has a diverse range of marine ecosystems in the coastal and insular areas of the Caribbean Sea and the Pacific Ocean. Seaweed research has focused mainly on the identification and taxonomic distribution of 628 species identified so far, mainly in the Caribbean Sea. Among the most widely cultivated genera of seaweeds in open-sea pilot systems in Colombia are Hydropuntia, Gracilaria, Hypnea, Kappaphycus, and Eucheuma. These genera have shown low yields as a consequence of high tissue fragility, epiphytism, sedimentation, and nitrogen deficiency. In addition, the evaluation of the biological activity of selected seaweed compounds has advanced considerably, focusing on their composition and their use for direct consumption by humans and animals. Despite the diversity of seaweeds, as well as certain technical and scientific advances, Colombia is still lagging behind other countries in seaweed exploitation, both in Latin America and worldwide. This current status raises the need to increase research, technological (agro-tech) appropriation, and the adoption of effective public policies that will boost algal businesses. In addition, seaweed cultivation could support the current blue economy transition in Colombia, which could eventually allow the country to enter the global seaweed market.

Recent advances in industrial applications of seaweeds

Seaweeds have been generally utilized as food and alternative medicine in different countries. They are specifically used as a raw material for wine, cheese, soup, tea, noodles, etc. In addition, seaweeds are potentially good resources of protein, vitamins, minerals, carbohydrates, essential fatty acids and dietary fiber. The quality and quantity of biologically active compounds in seaweeds depend on season and harvesting period, seaweed geolocation as well as ecological factors. Seaweeds or their extracts have been studied as innovative sources for a variety of bioactive compounds such as polyunsaturated fatty acids, polyphenols, carrageenan, fucoidan, etc. These secondary metabolites have been shown to have antioxidant, antimicrobial, antiviral, anticancer, antidiabetic, anti-inflammatory, anti-aging, anti-obesity and anti-tumour properties. They have been used in pharmaceutical/medicine, and food industries since bioactive compounds from seaweeds are regarded as safe and natural. Therefore, this article provides up-to-date information on the applications of seaweed in different industries such as pharmaceutical, biomedical, cosmetics, dermatology and agriculture. Further studies on innovative extraction methods, safety issue and health-promoting properties should be reconsidered. Moreover, the details of the molecular mechanisms of seaweeds and their bioactive compounds for physiological activities are to be clearly elucidated.

Impact of Blanching, Freezing, and Fermentation on Physicochemical, Microbial, and Sensory Quality of Sugar Kelp (Saccharina latissima)

Low seaweed consumption in the West is due to lack of availability and consumer familiarity. In this study, the effects of preservation processes on quality aspects of Saccharina latissima products were assessed. First, a blanching (100 °C for 1 or 3 min) treatment was used to produce seaweed salad. In a second study, effects of blanching, freezing, and fermentation on kelp quality were assessed and processed kelp was used to produce sauerkraut. Blanching significantly decreased (p ≤ 0.05) the instrumental kelp a* value and firmness. The a* value negatively correlated with overall liking of salads. To prepare sauerkraut, raw, raw/frozen (-20 °C), blanched (100 °C, 1 min), or blanched/frozen kelp were mixed with cabbage, salted, inoculated with starter cultures and fermented. Inconsistent trends in L* values, firmness, and fungi enumeration were observed after fermentation. Consumers evaluated kelp salad (n = 100) and sauerkraut (n = 80) for acceptability. Blanched kelp salad had higher hedonic scores than raw kelp salad. A 100% cabbage sauerkraut control and blanched kelp/cabbage blends were compared; kelp blends were similar to control for appearance, color, and texture but were lower for overall acceptability. Results suggest improved quality and enhanced consumer acceptability of seaweed products with use of minimal processing.

Protective Effect of Red Algae (Rhodophyta) Extracts on Essential Dietary Components of Heat-Treated Salmon

Salmon paste contains nutritious components such as essential fatty acids (EPA, DHA), vitamin E and astaxanthin, which can be protected with the addition of red algae extracts. Phenolic extracts were prepared with an ethanol: water mixture (1:1) from the red seaweeds Gracilaria chilensis, Gelidium chilense, Iridaea larga, Gigartina chamissoi, Gigartina skottsbergii and Gigartina radula, obtained from the Pacific Ocean. Most algae had a high content of protein (>7.2%), fiber (>55%) and β-glucans (>4.9%), all expressed on a dry weight basis. Total polyphenols (TP), total flavonoids (TF), antioxidant (DPPH, FRAP) and antibacterial power of the extracts were measured. In addition, the nutritional components of the algae were determined. Results showed that the content of TP in the six algae varied between 2.6 and 11.3 mg EAG/g dw and between 2.2 and 9.6 for TF. Also, the extracts of G. skottsbergii, G. chamissoi, G. radula and G. chilensis showed the highest antiradical activity (DPPH, FRAP). All samples exhibited a low production of primary oxidation products, and protection of the essential components and the endogenous antioxidants tocopherols and astaxanthin, particularly in the case of G. skottsbergii, G. chamissoi, G. radula and G. chilensis. Furthermore, all algae had inhibitory activity against the tested microorganisms, coincident with their antioxidant capacity. Results show that the extracts may have future applications in the development and preservation of essential dietary components of healthy foods.