Macroalgae have been regarded as a natural food source since ancient times, their nutritional value being not only proven by recent studies, but also triggering further in-depth research efforts on the matter. The present study aims to provide an insight into the nutritional potential of selected red seaweed species collected in central Portugal by specifically comparing the moist yield and ash content, crude protein, total lipids, carbohydrates and pigment content between species and, ultimately, finding out if there are differences between taxa. The results obtained highlighted the most nutritionally appealing species, namely, Plocamium cartilagineum with respect to protein content (23.18% dw) and Sphaerocococcus coronopifolius with respect to carbohydrate content (40.23% dw), while none of the species studied showed a lipid content higher than 1.80% dw. Regarding pigment content, the highest concentrations of phycoerythrin, carotenoid and chlorophyll a were obtained, respectively, from P. cartilagineum (0.09 mg.mL⁻¹), Porphyra umbilicalis (1.88 µg.g⁻¹ fw) and Jania rubens (38.41 µg.mL⁻¹). We concluded that there are significant differences between the species studied regarding their nutritional profile, with a marked difference between Corallinales and all other species not belonging to this order; regarding pigment content, this variation between orders was not observed. Nevertheless, all the studied species may act as promising complements in a human healthy diet.

Acorns, the seeds of oak trees, are pivotal in the Mediterranean region, historically serving as vital sustenance for wildlife and humans. Although traditionally used for livestock, in times of scarcity, acorns were also used in human diets together with their use in traditional medicine. In this review, we explore and deepen the multifaceted significance of oak species, consolidating nutritional data while emphasizing sustainable practices for modern dietary integration and potential applications in other areas, promoting long-term ecological balance. In the Mediterranean region, notable species are Quercus ilex, Q. faginea, Q. suber, and Q. coccifera, which differ in flavor, texture, and nutritional content. Rich in carbohydrates, acorns can contain up to 50% starch as well as amino acids, proteins, and lipids. This nutritional composition favors the preparation of flour for use in bread doughs or even diverse types of processing such as roasting, which makes it a substitute for coffee. Furthermore, acorn by-products, containing tannins, find applications in leather processing. This review highlights and summarizes in detail the nutritional potential, culinary adaptability, and diverse applications of acorns, emphasizing the need to preserve and utilize natural resources sustainably. In doing so, it sheds light on the often-overlooked value of these humble seeds.

Throughout the ages, macroalgae have provided humankind with elements beneficial to human health, and often with bioactive abilities. Yet, while today we fully acknowledge such potential, especially that of the most widely known species, an even greater number of species remain unaknowledged. This holds particularly true for the highly diverse phylum Rhodophyta (red seaweeds) and, therefore, the present study aims to unveil the antioxidant and the antimicrobial potential of twelve red seaweed species collected in central Portugal. Results obtained from the antioxidant assays ABTS and TPC highlighted the high scavenging capacity of the coralline algae Corallina officinalis, Ellisolandia elongata and Amphiroa rigida, and the high phenolic content of Porphyra umbilicalis, whereas the antimicrobial analyses through MIC determination emphasized the activities of Sphaerococcus coronopifolius and Mesophyllum lichenoides against, respectively, Bacillus subtilis and Saccharomyces cerevisiae. This study raised awareness of the bioactive potential waiting to be discovered regarding less known Rhodophyta species, such as Amphiroa rigida and Mesophyllum lichenoides. Therefore, we believe this study provides extra steps in pinpointing Rhodophyta species with bioactive potential, encouraging further studies tailored toward a biotechnological perspective, and, ultimately, influencing current perspectives regarding the exploration of seaweeds.

Acorns are an underutilized natural resource with significant potential for sustainable food systems. This study evaluates the nutritional composition and lipid profile of acorn flours from seven Quercus species (Q. pubescens, Q. ilex, Q. cerris, Q. petraea, Q. robur, Q. rotundifolia, and Q. suber) collected in the Iberian Peninsula and Croatia across different harvest years. Proximate composition, including moisture, ash, protein, lipids, total dietary fiber, sugars, and carbohydrates, was determined using standard AOAC methods, and fatty acid profiles were analyzed by gas chromatography. Rheological properties measured with a micro-visco-amylograph (MVA) revealed significant interspecific differences in viscosity and paste stability, reflecting intrinsic structural variability in the starch fraction among the studied species. The results revealed notable variability among species, sample types, and collection conditions. Acorn flours were characterized by high carbohydrate content (up to 74.8% dw), moderate lipid levels (reaching 16.9% dw in Q. pubescens flour), and low protein content, while shells exhibited markedly higher dietary fiber values (up to 77.0% dw in Q. robur shell). Lipid profiles were dominated by unsaturated fatty acids, particularly oleic (up to 63.7%) and linoleic acids. The differences observed between samples reflect cumulative variability that may be associated with species, geographical origin, harvest year, and processing conditions, although these factors remain confounded in the current study. Because of the confounded sampling design, observed differences represent combined population diversity and should be validated in future balanced trial designs. These findings highlight the high nutritional density of acorns as sustainable, gluten-free ingredients and provide a scientific framework for their industrial use in developing novel functional foods and circular economy models.

Acorns (Quercus spp.) are an underutilized forest resource with recognized nutritional and bioactive potential, making them promising candidates for the development of sustainable plant-based functional foods. This study aimed to valorize acorns through the formulation of two novel acorn-based products, a plant-based beverage, and a pudding, and to assess their nutritional properties, sensory acceptability, and, for the beverage, refrigerated shelf-life stability. The beverage was optimized as a neutral-flavored milk alternative, using sodium alginate as a natural clean-label stabilizer to enhance emulsion stability and physicochemical properties. The final formulation exhibited low energy density and a lipid profile rich in monounsaturated fatty acids, contributing to its nutritional and functional value. Throughout 63 days of storage at 4 °C, sodium alginate effectively prevented phase separation and supported the retention of antioxidant capacity, as evidenced by stable ferric reducing antioxidant power (FRAP) and total phenolic content, although ABTS radical scavenging activity declined over time. No microbial growth was detected during storage, confirming the adequacy of the applied thermal treatment and aseptic filling procedures applied. The acorn-based pudding, developed by adapting a traditional egg-based recipe, functioned as a proof of concept illustrating the technological versatility of acorns across distinct plant-based matrices, exhibiting a nutritional profile comparable to commercial counterparts and high consumer acceptability. Overall, this work demonstrates the technological feasibility and versatility of incorporating acorns into plant-based food matrices, supporting their potential as sustainable ingredients for the development of innovative value-added foods and contributing to the valorization of forest resources.