Katarzyna Chojnacka

Biologically Active Compounds in Seaweed Extracts - the Prospects for the Application

The paper covers the latest developments in research on the utilitarian properties of algal extracts. Their appli- cation as the components of pharmaceuticals, feeds for animals and fertilizers was discussed. The classes of various bio- logically active compounds were characterized in terms of their role and the mechanism of action in an organism of hu- man, animal and plant. Recently, many papers have been published which discuss the methods of manufacture and the composition of algal ex- tracts. The general conclusion is that the composition of extracts strongly depends on the raw material (geographical loca- tion of harvested algae and algal species) as well as on the extraction method. The biologically active compounds which are transferred from the biomass of algae to the liquid phase include polysaccharides, proteins, polyunsaturated fatty ac- ids, pigments, polyphenols, minerals, plant growth hormones and other. They have well documented beneficial effect on humans, animals and plants, mainly by protection of an organism from biotic and abiotic stress (antibacterial activity, scavenging of free radicals, host defense activity etc.) and can be valuable components of pharmaceuticals, feed additives and fertilizers.

Evaluation of Supercritical Extracts of Algae as Biostimulants of Plant Growth in Field Trials

The aim of the field trials was to determine the influence of supercritical algal extracts on the growth and development of winter wheat (variety Akteur). As a raw material for the supercritical fluid extraction, the biomass of microalga Spirulina plantensis, brown seaweed – Ascophyllum nodosum and Baltic green macroalgae was used. Forthial and Asahi SL constituted the reference products. It was found that the tested biostimulants did not influence statistically significantly the plant height, length of ear, and shank length. The ear number per m2 was the highest in the group where the Baltic macroalgae extract was applied in the dose 1.0 L/ha (statistically significant differences). Number of grains in ear (statistically significant differences) and shank length was the highest in the group treated with Spirulina at the dose 1.5 L/ha. In the group with Ascophyllum at the dose 1.0 L/ha, the highest length of ear was observed. The yield was comparable in all the experimental groups (lack of statistically significant differences). Among the tested supercritical extracts, the best results were obtained for Spirulina (1.5 L/ha). The mass of 1000 grains was the highest for extract from Baltic macroalgae and was 3.5% higher than for Asahi, 4.0% higher than for Forthial and 18.5% higher than for the control group (statistically significant differences). Future work is needed to fully characterize the chemical composition of the applied algal extracts. A special attention should be paid to the extracts obtained from Baltic algae because they are inexpensive source of naturally occurring bioactive compounds, which can be used in sustainable agriculture and horticulture.

Determination of the reference value of nitrogen mass fraction in the reference material of Polish soil

Ensuring a traceability and meaningful of a measurements is one of the most important stages of each analysis, each measurement. It is especially important for measurement of the environmental samples, like soil, which is a very complex matrix. A certified reference materials (CRMs) should be routinely used for this purpose. The paper discusses the procedure for preparation of the soil samples for certification as CRM. As for agricultural reasons there is a growing demand for CRMs regarding a nitrogen mass fraction in the Polish soil, we prepared such a material and established the reference value with associated measurement uncertainty. Homogeneity and stability of the material were shown to be appropriate for the intended purpose. The presented approach can also be used in a process of manufacture of a laboratory reference material, which can be used for a routine quality control.

Introduction: Toward Algae-Based Products

This book provides an overview of the importance of different forms of algae (microalgae, as well as marine and freshwater macroalgae) in different applications. Algae as a renewable biomass can be used as a component in the production of a wide array of products, including food, pharmaceuticals, health-related products, nutraceuticals, cosmetics, fine chemicals (dyes and colorants), feed components, feed additives, aquaculture products, and agriculture products (fertilizers, biostimulants for plant growth). Recently, novel and emerging technologies have been developed to convert algal biomass into valuable products and extract biologically active compounds from algae in an efficient and environmentally friendly manner. This book describes the characteristic features of algae cultivation, identification, and production, as well as its subsequent applications. Algae-based products may play an important role in a sustainable future. The development of an algal sector in industry could help to solve many of the problems that modern society is currently facing, including the security of energy and water, food supplies, and climate protection.

The Environmental Benefits Arising from the Use of Algae Biomass in Industry

The replacement of nonrenewable raw materials with renewables is a strategy that has gained much attention in the face of high-energy consumption and increasing CO2 emissions. The introduction of algae biomass into industry could contribute to solving some of the main challenges that modern society faces: energy security, precarious water and food supplies, and climate change. Algae are considered as potential feedstock candidates for many products, such as food, feed, biofuels, biofertilizers, and cosmetics. Goods obtained from algae biomass are considered sustainable, renewable, and environmentally friendly, as they are generally formed through photosynthesis and use atmospheric CO2 and sunlight to produce oxygen and high-energy carbonaceous compounds (i.e., biomass) that can be transformed into valuable products. They can be produced locally on non-arable lands. An additional benefit of the application of algae is their productivity rates, which are higher than those of terrestrial biomass, such as corn. It has been suggested that wastewaters and wastes rich in organic and inorganic nutrients may be used in place of freshwater and fertilizers in algae cultivation. Thus, the utilization of waste and wastewaters to cultivate algae could simultaneously solve the problems of freshwater demand, the high cost of nutrients, and the need to remediate waste.

The Methods of Algal Biomass Extraction: Toward the Application

Increasing customer need for natural products of both high and well-defined activity has enhanced the use of biological materials, such as algal biomass. At the same time, algae transport and storage issues, concerning fresh seaweeds in particular, have led to the development of biomolecule isolation, including extraction. To the best of our knowledge, various approaches have been successfully applied in extracting biologically active compounds from algal biomass, among which solvent and temperature treatment are the most common. Considering novel methods, processing under high pressure (pressurized liquid and supercritical fluid extraction) and ultrasound-, microwave-, and enzyme-assisted extraction have been reported. The approaches differ in their efficacy and selectivity and extract purity, determining the usability of the final product in either bulk manufacturing or as a high-value material. Application of algae-based constituents in food and beverage products, dietary and feed supplements, cosmetics, and pharmaceuticals is being widely discussed. Recently, the usability of algae oil in the technology of biofuels has been extensively examined. In the current work, preparation of algal extracts and formulations for potential industrial use are discussed.

Algae As Fertilizers, Biostimulants, and Regulators of Plant Growth

Currently, legislation restricts the use of mineral fertilizers and pesticides and thus forces a new approach to reducing the use of chemical products through either parallel application or partial replacement with formulations capable of enhancing the efficiency of conventional treatment. Among the natural materials of such capability are algae, which contain a variety of biologically active compounds verified to have a beneficial influence on plants. Algal derivatives have been confirmed to provide crops with nutrients, increase biomass production, and activate the natural ability of plants to respond properly to stress agents. Depending on the formulation, algae-based products might show the functionality of organic fertilizers or components of organo-mineral fertilizers, soil amendments (improvers), (bio)stimulants, and pesticides. However, current European rules are not harmonized at the union level. Until a single market is established, algae’s potential for plant growth enhancement will not be sufficiently developed. There are, however, new strategies for elaborating EU-wide standards and regulations governing products obtained within value chains based on secondary feedstock.

Seaweeds As a Component of the Human Diet

Algae (microalgae and seaweeds) have been used for centuries as food, animal fodder and a source of chemicals for the pharmaceutical, cosmetic, food and chemical industries. In the last few decades, knowledge about the influence of algae in diet on health and well-being has increased. Algae still gain attention due to their unique composition. They are known to be a rich concentrate of biologically active compounds, such as carbohydrates, proteins, minerals, oils, fats, polyunsaturated fatty acids, antioxidants (polyphenols, tocopherols, vitamin C, mycosporine-like amino acids) and pigments. Besides the nutritional value of algae, bioactive compounds play a significant role in the promotion of human health and disease prevention, due to antibacterial, antiviral, antifungal, antioxidative, anti-inflammatory and antitumor properties. Algal products can be used for performance improvement and the reduction of pathogenic bacteria. Algae can be served in different forms – whole seaweed meal, powder, extract, homogenate or fermented. In this chapter, the advantages (nutritional value, accessibility, etc.) and disadvantages (toxic metals, sensory perception, etc.) of the application of seaweeds as a component of food are discussed. Special attention is paid to their application in cereals, dairy and meat products. Seaweeds can also serve as a natural salt, as well as a source of hydrocolloids, especially in the confectionery industry. Macroalgae can also deliver biologically active compounds to food products of plant and animal origin indirectly, through their application in plant cultivation and animal feeding. It is predicted that seaweeds as food and seaweed-derived food flavours, colours and nutrients will continue to attract considerable commercial attention.