Nettle, a Long-Known Fiber Plant with New Perspectives

Isolation and characterization of nettle (Urtica dioica L.) seed proteins: Conversion of underutilized by-products of the edible oil industry into food emulsifiers

This study aimed to upcycle a byproduct of the edible oil industry, cold-pressed nettle seed meal (CPNSM), into a plant-based emulsifier, thereby increasing the sustainability of the food system. The protein content of the nettle seed protein (NSP) powder was 48.3% with glutamic acid (16.6%), asparagine (10.7%), and arginine (9.7%) being the major amino acids. NSPs had a denaturation temperature of 66.6 °C and an isoelectric point of pH 4.3. They could be used as emulsifiers to form highly viscous coarse corn oil-in-water emulsions (10% oil, 4% NSP). Nevertheless, 10-fold diluted emulsions exhibited rapid creaming under different pH (2-9), salt (0-500 mM NaCl) and temperature (>40 °C) conditions, but they were relatively stable to aggregation. Our findings suggest that NSPs could be used as emulsifiers in highly viscous or gelled foods, like dressings, sauces, egg, cheese, or meat analogs.

Era of bast fibers-based polymer composites for replacement of man-made fibers

Bast fibers are defined as those obtained from the outer cell layers of the bast of various plant families. They are finding use in textile applications and are widely used as reinforcements for green composites, as bast fibers are perceived as "sustainable". There is a growing demand for bast fibers across the world due to their renewable and biodegradable nature. The bast fibers are mainly composed of cellulose, which potentially considers the growing techniques, harvesting and extraction processes of bast fibers most used to produce fibers with appropriate quality to apply in the daily lives of modern men and women in contemporary society. This review paper looks at many aspects of natural fibers, with a focus on plant bast fibers, including their impact on prehistoric and historical society. This review shows that bast fibers are competitive compared to man-made fibers in many applications, but variability in mechanical properties and low tenacity may limit their use in high-strengthh composites and extend to, particularly in aerospace, automotive, packaging, building industries, insulation, E-composites (Eco composites), geotextiles and many other applications are currently being explored. Considering, important characteristics of bast fibers include physical, mechanical, and chemical properties. This makes bast fibers one of the most important classes of plant fibers to use as reinforcing agents in thermosetting/thermoplastic polymer matrices. And the effect of bast fibers as reinforcement in the properties of ECO-composites, GREEN-composites, BIO-composites, lightweight composites. Bast fibers play an important role in sustainability, the preservation of the health of the environment, the well-being of the next generation, and even the daily lives of men and women in the contemporary world.

Primer pairs, PCR conditions, and peptide nucleic acid clamps affect fungal diversity assessment from plant root tissues

High-throughput sequencing has become a prominent tool to assess plant-associated microbial diversity. Still, some technical challenges remain in characterising these communities, notably due to plant and fungal DNA co-amplification. Fungal-specific primers, Peptide Nucleic Acid (PNA) clamps, or adjusting PCR conditions are approaches to limit plant DNA contamination. However, a systematic comparison of these factors and their interactions, which could limit plant DNA contamination in the study of plant mycobiota, is still lacking. Here, three primers targeting the ITS2 region were evaluated alone or in combination with PNA clamps both on nettle (Urtica dioica) root DNA and a mock community. PNA clamps did not improve the richness or diversity of the fungal communities but increased the number of fungal reads. Among the tested factors, the most significant was the primer pair. Specifically, the 5.8S-Fun/ITS4-Fun pair exhibited a higher OTU richness but fewer fungal reads. Our study demonstrates that the choice of primers is critical for limiting plant and fungal DNA co-amplification. PNA clamps increase the number of fungal reads when ITS2 is targeted but do not result in higher fungal diversity recovery at high sequencing depth. At lower read depths, PNA clamps might enhance microbial diversity quantification for primer pairs lacking fungal specificity.

Soluble and Insoluble Dietary Fibre in Date Fruit Varieties: An Evaluation of Methods and Their Implications for Human Health

Dietary fibre analysis is expensive due to its reliance on enzymes such as α-amylase, protease, and amyloglucosidase. This study investigated whether enzymes are essential in analysing insoluble, soluble, and total dietary fibre (IDF, SDF and TDF) contents in dry fruits with very low starch and protein contents. The IDF, SDF, and TDF were measured in date fruits using the enzymatic gravimetric method AOAC 991.43 in the ANKOM dietary fibre analyser, with and without enzymatic digestion. The study analysed six date fruit varieties with a range of texture profiles. Our results highlighted agreement between both methods in the measured IDF, SDF, and TDF values. TDF values in date fruit varieties varied considerably, from 5.67% g/100 g to 10.33% g/100 g. Results from both methods also indicate that IDF constituted the bulk of dietary fibre content in all date fruit varieties (77.8% to 91.6%), while the proportion of SDF was between 8.4% and 22.2%. This study confirms that dates are a rich source of dietary fibre, and can be a valuable functional ingredient in foods that reduce the risk of chronic diseases. The study confirmed that the inexpensive non-enzymatic technique is a viable substitute for the enzymatic method for analysing dietary fibre in dry fruits.

Ecological Insight, Anatomical Features, and Fiber Characterization of Leptadenia pyrotechnica (Forrsk.) Decne. as a Promising Resource

Wild plants are considered promising natural eco-friendly resources for fibers. Leptadenia pyrotechnica is a xerophytic shrub that flourishes in a sandy desert habitat with high biomass production; therefore, it could be a potential resource for fibers. The present study aimed to investigate the vegetation composition of L. pyrotechnica communities and their correlation with soil variables. Additionally, this study aimed to evaluate the anatomical features of the stem as well as fiber characteristics, including chemical, biometry, morphological, and optical properties. The vegetation analysis showed the presence of 60 species belonging to 22 families, with a prevalence of therophytes. Four communities were determined, dominated by L. pyrotechnica and with co-dominance of the shrubs Haloxylon salicornicum, Ochradenus baccatus, and Retama raetam. The soil organic matter, salinity, texture, and cations were parameters that substantially affect the L. pyrotechnica community. The anatomical investigation showed the structural (anatomical) adaptation of L. pyrotechnica to arid habitats. Chemical analysis of the raw plant material revealed satisfactory levels of cellulose and hemicellulose (48.61% and 18.59%), while lignin and ash contents were relatively low, compared to hardwoods and softwoods. The fiber characterization revealed that fibesr length was 0.72 mm, while width and cell wall thickness were 20.46 and 6.48 μm, respectively. The optical properties revealed a birefringence of 0.028, indicating a good refractive index. These fiber characteristics showed that L. pyrotechnica could be used as raw material for the production of good-quality paper. A further feasibility study is recommended for the evaluation of L. pyrotechnica fibers, as a promising resource for papermaking at a large scale.