The Influence of pH of Extracting Water on the Composition of Seaweed Extracts and Their Beneficial Properties onLepidium sativum

Abstract

Baltic seaweeds were used to obtain aqueous extracts (E) through changing initial pH of deionised water added to algal biomass (EpH3·H2O, EpH7·H2O, and EpH10·H2O) and through changing pH of the mixture of algae and deionised water (EpH3, EpH7, and EpH10). Algal extracts were characterized in terms of the concentration of polyphenols and micro- and macroelements. The highest concentration of polyphenols was determined in extract EpH3 and the lowest in extract EpH10·H2O. It was found that the obtained extracts had similar concentrations of elements (except EpH3). The phytotoxicity of algal extracts (0.5, 2.5, and 10%) was examined in the germination tests on Lepidium sativum. No phytotoxic effects were observed. It was found that they had beneficial effects on the cultivated plants (length and weight). The best biostimulant effect was observed in the groups treated with EpH3 (2.5%), EpH7 (2.5%), and EpH7 (10%). The dry weight of plants was similar in all the groups. Algal extract also improved the multielemental composition of plant. The greatest concentration of total chlorophyll in plants was obtained by using extract EpH10·H2O, 0.5%. These results proved that algal extracts have high potential to be applied in cultivation of plants.

The Effect of Plant-Derived Biostimulants on White Head Cabbage Seedlings Grown under Controlled Conditions

“…A large number of existing studies have disclosed the beneficial effects of algal extracts application on plants, such as seed germination, increased crop yield and nutritional value, flower set and fruit production, raised resistance to stress (biotic and abiotic), and enhanced postharvest shelf-life of perishable products [3,20,[27][28][29][30][31][32]. Currently, in comparison with seaweeds, much less is known regarding the activity of botanical biostimulants.…”

Mineral Composition of Subcritical Water Extracts of Saccorhiza Polyschides, a Brown Seaweed Used as Fertilizer in the North of Portugal

“…Generally, these studies show that increasing the extraction temperature leads to higher mineral concentration in the final extract [15][16][17]. Another conclusion is that seaweed extracts have in common higher levels of Na, K, P, Ca, and Mg, and its levels are related to the raw material and the extraction method [15][16][17]. Lotze et al [18] determined the nutrient composition of three commercial seaweed biostimulants.…”

“…K and Na were the main minerals present in all samples. Godlewska et al prepared seaweeds extracts using an aqueous solution with different pH [15], at room or boiling temperature [16] and compared its Ca, K, Mg, Na, P, S, B, Cu, Fe, Mn, Mo, Si, and Zn content. In all extracts, Na, K, and Mg were the minerals present at higher concentrations, and the higher amounts were present when using water at pH 7 and higher temperatures.…”

In Vitro Evaluation of the Antibacterial and Antioxidant Activities of Extracts of Gracilaria gracilis with a View into Its Potential Use as an Additive in Fish Feed

“…Damselae, and V. anguillarum. In similar studies conducted by other authors [26,63,64], it was found that the effectiveness of extraction is strongly conditioned by the different extraction conditions that in turn affects the type of compounds extracted. In the present study, we demonstrated that a temperature of 40 • C is generally the most effective when associated to an extraction time of 30 min.…”

“…The use of macroalgae as an additive in feed can be achieved in the form of biomass or an extract, the latter being obtained with non-toxic and appropriate grade solvents with subsequent incorporation during the feed manufacturing process. Several studies demonstrate that the activities exhibited by crude extracts are different depending on the temperature, extraction time, and solvents used [26,[62][63][64], the most common including water, ethanol, hexane, methanol, and mixtures of different solvents. The different extraction solvents according to their polarity allow the fractionation and separation of different compounds such as pigments (chlorophyll a and b and carotenoids), alkaloids, and different classes of phenolic compounds, among others.…”