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

Impact of the drying process on the flavor characteristics of two economically important laver species, Pyropia haitanensis and Neopyropia yezoensis

This study investigated the impact of drying process on the flavor profiles of the economically significant Pyropia haitanensis and Neopyropia yezoensis, aiming to clarify how species differences and drying process influence volatile and non-volatile flavor compounds. Using GC × GC-TOFMS and LC-MS, the volatile metabolites, free amino acids (FAAs), and nucleotides were analyzed. A total of 2774 volatile components, including 76 odor-active compounds (OACs), were identified, with aldehydes, ketones, benzenoids, and pyrazines as dominant contributors. The key volatiles responsible for their unique flavor were 2-nonenal, 2-octenal, heptanal, 2-pentylfuran, and 1-octen-3-one. Fresh P. haitanensis exhibited a superior flavor profile due to higher OACs and umami compounds, while high-temperature drying significantly enhanced the umami and sweet flavor notes in N. yezoensis by increasing aromatic volatiles and umami FAAs. These findings demonstrate that species differences and processing methods significantly influence laver flavor, providing valuable insights for improving product quality.

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.

Effects of pan- and air fryer-roasting on volatile and umami compounds and antioxidant activity of dried laver (Porphyra dentata)

This study aimed to investigate the impact of pan- and air fryer-roasting on the volatiles, umami compounds, antioxidant activity, and sensory attributes of dried laver (Porphyra dentata). To assess the influence of time and temperature, pan-roasting was conducted at temperatures of 250, 300, and 350 °C for 5, 10, and 15 s, respectively. For air fryer-roasting, dried laver was roasted at 160, 170, and 180 °C for 2, 4, and 6 min, respectively. In both roasting methods, the levels of 1,5-octadien-3-ol and 1-octen-3-ol significantly decreased (p < 0.05) with increased time and temperature. The Equivalent Umami Concentration ranged from 94.89 to 518.09 g MSG/100 g. The antioxidant activity significantly increased (p < 0.05) with higher roasting temperatures and longer durations, whereas pigment content significantly decreased. The browning index increased by 64% and 43% for the pan and air frying methods, respectively. The samples pan-roasted at 300 °C for 15 s obtained the highest sensory scores.

Green Seaweeds as a Potential Source of Biomolecules and Bioactive Peptides: Recent Progress and Applications - A Review

Over the past few decades, seaweed has been explored as a sustainable source in biotechnological and biomedical industries because of its multiple biopotential actions. However, the composition of biomolecules such as carbohydrates, lipids, fatty acids, free amino acids, ash, minerals, vitamins, and especially protein in green seaweeds varies from species to species based on their growth stage and the environmental conditions. Specifically, seaweed-derived bioactive proteins and peptides have the potential for several health benefits. They serve as a balanced diet. Protein which is an extensive macronutrient in human nutrition, should be explored to avoid using animal-sourced protein, which is expensive to consume. Bioactive peptides that are isolated from marine algae consist of various kinds of functional properties. In the food industry, seaweeds are novel molecules for being used in both nutritional foods and nutraceuticals. In both in vitro and In vivo conditions, various seaweed-derived bioactive compounds have shown a broad range of biological activities including anti-cancer and immunomodulatory, anti-hypertensive, and anti-coagulant activities. Hence, this review paper discusses the screening of seaweed-derived biochemicals with a special focus on their proteins, peptide contents, and nutra-pharmaceutical values.

Atlantic Canadians' Sensory Perception of Couscous Made with Sugar Kelp (Saccharina latissma)

Sugar kelp (Saccharina latissma) has many nutritional benefits and has been identified as a rich source of fibre, vitamins, and antioxidants. However, it is not regularly consumed in the Western world, and the sensory perception of foods containing sugar kelp must be investigated to increase acceptance in North America. This study evaluated consumers' (n = 99) sensory perception of couscous with increasing amounts of sugar kelp (0% (control), 4%, 6%, 8%, and 10% wt/wt). Furthermore, consumers' purchase intent, liking, and emotional response to couscous with added sugar kelp was evaluated with and without nutritional information. Sugar kelp at 6% incorporation did not impact the consumers' liking scores ("Like Slightly" on the hedonic scale), but at 8% the consumers' liking significantly decreased ("Neither Like nor Dislike"). The 8% and 10% levels of sugar kelp addition led to astringency, bitter, hard, brackish, fishy, and chewy attributes being perceived by the consumers. The consumers identified they preferred samples that had soft, savoury, salty, and bland flavours and disliked samples that were brackish and gritty. The nutritional information did not increase overall liking scores, purchase intent, or emotional response. However, the inclusion of sugar kelp in the couscous did lead to an increased selection of positive emotions like happy, joyful, pleasant, and enthusiastic. Overall, the consumers were interested in foods containing seaweed and believed they were nutritious. The results indicated that sugar kelp could be added to couscous up to 6% wt/wt without impacting overall liking.

Incorporation of Sea Spaghetti (Himanthalia elongata) in Low-Salt Beef Patties: Effect on Sensory Profile and Consumer Hedonic and Emotional Response

Seaweed is a naturally rich source of nutrients and exhibits techno-functional properties that are under study for their potential as ingredients in meat products. However, seaweed is associated with a particular flavor profile, and optimization of the sensory profile should be conducted alongside technical performance. This study investigated the feasibility of the application of sea spaghetti (Himanthalia elongata) in the production of low-salt beef patties and recorded the associated sensory profile and consumer hedonic-emotional response. Eight beef patty formulations with varying salt (0-1%) and seaweed (0-5%) contents were subjected to quantitative descriptive analysis via a trained sensory panel (n = 8) and six the formulations were selected for consumer testing (liking, emotional associations, saltiness perception, and purchase intent) by a group of 105 Irish resident consumers. The trained panel results showed that the intensity of seaweed odor, flavor, and visual presence in burgers was negatively related to the intensity of beef odor and flavor and that seaweed addition (5%) significantly increased the saltiness perception of low-salt burgers. Burgers with 1% added seaweed, although perceived by consumers as less salty, could substitute NaCl in low-salt beef patties without deterioration of their liking among regular burger consumers. Consumers associated all seaweed-containing samples, especially those containing 1% of sea spaghetti, with being good, pleasant, satisfied, and warm. The higher inclusion of sea spaghetti (2.5%) led to significantly lower overall liking and reduced purchase intent, while consumers associated this formulation with emotions such as being more adventurous, aggressive, and wild. Consumers who rejected seaweed burgers had the highest level of food neophobia and avoided foods with additives. The results demonstrate that 1% sea spaghetti seaweed can be successfully incorporated into low-salt beef patties, resulting in hedonic and emotional benefits without significantly increasing the salt content.

Seaweed Proteins: A Step towards Sustainability?

This review delves into the burgeoning field of seaweed proteins as promising alternative sources of protein. With global demand escalating and concerns over traditional protein sources' sustainability and ethics, seaweed emerges as a viable solution, offering a high protein content and minimal environmental impacts. Exploring the nutritional composition, extraction methods, functional properties, and potential health benefits of seaweed proteins, this review provides a comprehensive understanding. Seaweed contains essential amino acids, vitamins, minerals, and antioxidants. Its protein content ranges from 11% to 32% of dry weight, making it valuable for diverse dietary preferences, including vegetarian and vegan diets. Furthermore, this review underscores the sustainability and environmental advantages of seaweed protein production compared to traditional sources. Seaweed cultivation requires minimal resources, mitigating environmental issues like ocean acidification. As the review delves into specific seaweed types, extraction methodologies, and functional properties, it highlights the versatility of seaweed proteins in various food products, including plant-based meats, dairy alternatives, and nutritional supplements. Additionally, it discusses the potential health benefits associated with seaweed proteins, such as their unique amino acid profile and bioactive compounds. Overall, this review aims to provide insights into seaweed proteins' potential applications and their role in addressing global protein needs sustainably.

Modified Atmosphere Packaging (MAP) for Seaweed Conservation: Impact on Physicochemical Characteristics and Microbiological Activity

Conventional conservation techniques such as drying, salting or freezing do not allow for preserving the original characteristics of seaweeds. The present work aims to study the impact of minimal processing, in particular "Modified Atmosphere Packaging" (MAP), on the physicochemical characteristics and food safety of two seaweed species, "laver" (Porphyra umbilicalis) and "sea-lettuce" (Ulva lactuca), stored at 6 °C for 15 days. Different parameters were evaluated using analytical methods, namely the composition of headspace gases, color, texture, microorganisms, and volatile organic compounds (VOCs). The main findings of this study were that the MAP treatment was able to inhibit the respiration rate of minimally processed seaweeds, also preserving their color and texture. There was a remarkable reduction in the microbial load for P. umbilicalis treated under modified and vacuum atmospheres, and U. lactuca exhibited relatively steady values with no notable differences between the treatments and the control. Therefore, during the 15-day study period, both seaweeds met the requirements for food safety. GC-TOF-MS allowed to conclude that both MAP and vacuum treatments were more efficient in maintaining the odor characteristics of U. lactuca compared to P. umbilicalis with no significant differences throughout the storage days. Metabolic responses to diverse sources of abiotic stress seemed to account for most of the changes observed.

An overview on the nutritional and bioactive components of green seaweeds

Green seaweed, as the most abundant species of macroseaweeds, is an important marine biological resource. It is a rich source of several amino acids, fatty acids, and dietary fibers, as well as polysaccharides, polyphenols, pigments, and other active substances, which have crucial roles in various biological processes such as antioxidant activity, immunoregulation, and anti-inflammatory response. In recent years, attention to marine resources has accelerated the exploration and utilization of green seaweeds for greater economic value. This paper elaborates on the main nutrients and active substances present in different green seaweeds and provides a review of their biological activities and their applications for high-value utilization.

Graphical abstract