Bioactives Obtained From Plants, Seaweeds, Microalgae and Food By-Products Using Pressurized Liquid Extraction and Supercritical Fluid Extraction

Emerging technologies for the extraction of bioactives from mushroom waste

Extraction of bioactive compounds for application in nutraceuticals is gaining popularity. For this, there is a search for low-cost substrates that would make the end product and the process more economical. Mushroom waste (stalk, cap, stem etc.) is one such high valued substrate that has received much attention recently due to its rich reserves of terpenoids, polyphenols, sesquiterpenes, alkaloids, lactones, sterols, antioxidative vitamins, anthocyanidins, glycoproteins and polysaccharides, among others. However, there is a need to identify green and hybrid technologies that could make the bioactive extraction process from these substrates safe, efficient and sustainable. To this effect, many emerging technologies (supercritical fluid, ultrasound-, enzyme- and microwave-assisted extraction) have been explored in the last decade which have shown potential for scale-up with high productivity. This review systematically discusses such technologies highlighting the current challenges faced during waste processing and the research directives needed for further advancements in the field.

Current extraction methods and potential use of essential oils for quality and safety assurance of foods

Essential oils (EOs) or vegetable oils have become the focus of several studies because of their interesting bioactive properties. Their application has been successfully explored in active packaging, edible coatings, and as natural flavoring to extend the shelf life of various types of food products. In addition, alternative methods of extraction of EOs (ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction and supercritical fluid extraction) have been shown to be more attractive than traditional methods since they present better efficiency, shorter extraction times and do not use toxic solvents. This review paper provides a concise and critical view of extraction methods of EOs and their application in food products. The researchers involved in the studies approached in this review were motivated mainly by concern about food quality. Here, we recognize and discuss the major advances and technologies recently used to enable shelf life extension of food products.

A Review of Antiviral and Antioxidant Activity of Bioactive Metabolite of Macroalgae within an Optimized Extraction Method

Non-conventional extraction of bioactive metabolites could provide sustainable alternative techniques to preserve the potency of antioxidants and antiviral compounds extracted from macro-algae. In this paper, we first reviewed the antioxidant and antiviral potential of the active metabolites that exist in the three known macro-algae classes; Phaeophyceae, Rhodophyceae, and Chlorophyceae, and a comparison between their activities is discussed. Secondly, a review of conventional and non-conventional extraction methods is undertaken. The review then focused on identifying the optimal extraction method of sulphated polysaccharide from macro-algae that exhibits both antiviral and antioxidant activity. The review finds that species belonging to the Phaeophyceae and Rhodophceae classes are primarily potent against herpes simplex virus, followed by human immunodeficiency virus and influenza virus. At the same time, species belonging to Chlorophyceae class are recorded by most of the scholars to have antiviral activity against herpes simplex virus 1. Additionally, all three macro-algae classes exhibit antioxidant activity, the potency of which is a factor of the molecular structure of the bioactive metabolite as well as the extraction method applied.

Subcritical Water Extraction of Salvia miltiorrhiza

In this work, a green extraction technique, subcritical water extraction (SBWE), was employed to extract active pharmaceutical ingredients (APIs) from an important Chinese medicinal herb, Salvia miltiorrhiza (danshen), at various temperatures. The APIs included tanshinone I, tanshinone IIA, protocatechualdehyde, caffeic acid, and ferulic acid. Traditional herbal decoction (THD) of Salvia miltiorrhiza was also carried out for comparison purposes. Reproduction assay of herbal extracts obtained by both SBWE and THD were then conducted on Caenorhabditis elegans so that SBWE conditions could be optimized for the purpose of developing efficacious herbal medicine from Salvia miltiorrhiza. The extraction efficiency was mostly enhanced with increasing extraction temperature. The quantity of tanshinone I in the herbal extract obtained by SBWE at 150 °C was 370-fold higher than that achieved by THD extraction. Reproduction evaluation revealed that the worm reproduction rate decreased and the reproduction inhibition rate increased with elevated SBWE temperatures. Most importantly, the reproduction inhibition rate of the SBWE herbal extracts obtained at all four temperatures investigated was higher than that of traditional herbal decoction extracts. The results of this work show that there are several benefits of subcritical water extraction of medicinal herbs over other existing herbal medicine preparation techniques. Compared to THD, the thousand-year-old and yet still popular herbal preparation method used in herbal medicine, subcritical water extraction is conducted in a closed system where no loss of volatile active pharmaceutical ingredients occurs, although analyte degradation may happen at higher temperatures. Temperature optimization in SBWE makes it possible to be more efficient in extracting APIs from medicinal herbs than the THD method. Compared to other industrial processes of producing herbal medicine, subcritical water extraction eliminates toxic organic solvents. Thus, subcritical water extraction is not only environmentally friendly but also produces safer herbal medicine for patients.

Main bioactive phenolic compounds in marine algae and their mechanisms of action supporting potential health benefits

Given the growing tendency of consumers to choose products with natural ingredients, food industries have directed scientific research in this direction. In this regard, algae are an attractive option for the research, since they can synthesize a group of secondary metabolites, called phenolic compounds, associated with really promising properties and bioactivities. The objective of this work was to classify the major phenolic compounds, compare the effectiveness of the different extractive techniques used for their extraction, from traditional systems (like heat assisted extraction) to the most advance ones (such as ultrasound, microwave or supercritical fluid extraction); the available methods for identification and quantification; the stability of the enriched extract in phenolic compounds and the main bioactivities described for these secondary metabolites, to offer an overview of the situation to consider if it is possible and/or convenient an orientation of phenolic compounds from algae towards an industrial application.

Panax ginseng callus, suspension, and root cultures: extraction and qualitative analysis

Introduction. In recent years, scientists have been actively searching for medicinal plants containing biologically active substances with geroprotective properties to treat diseases of old age, in particular cancer, diabetes, cardiovascular diseases, and others. Ginseng (Panax ginseng L.) is a promising source of geroprotective compounds. We aimed to select optimal parameters for extracting organic compounds from ginseng callus, suspension, and root cultures and analyze their qualitative composition. Study objects and methods. We studied ginseng callus, suspension, and root cultures, as well as their extracts. Biologically active substances were extracted with 30 to 70% ethanol. Organic compounds were determined by thin-layer chromatography. The results for each plant were archived and analyzed for the presence of quercetin, mangiferin, luteolin, rutin, quercetin-2-D-glucoside, malvidin, as well as caffeic, cinnamic, ferulic, and sinapinic acids. Results and discussion. We developed a procedure for screening solvents and performed a fractional qualitative analysis of biologically active substances extracted from ginseng. As a result, we established the optimal parameters for extracting biologically active substances from the dried biomass of ginseng cultures. In all cases, temperature and the ratio of solvent to biomass were the same (50°C, 1:5). However, the extraction time and ethanol concentration differed, amounting to 60 min and 50% for callus cultures, 30 min and 60% for suspension cultures, and 60 min and 70% for root cultures. The qualitative analysis of organic compounds showed the presence of rutin (0.25), quercetin (0.75), and mangiferin (0.57), as well as caffeic and sinapinic acids in the extracts. Conclusion. Our set of experiments to isolate biologically active substances from ginseng callus, suspension, and root cultures resulted in selecting the optimal extraction parameters and analyzing the extracts for the presence of organic compounds.

Emerging techniques for cell disruption and extraction of valuable bio-molecules of microalgae Nannochloropsis sp

Microalgae of Nannochloropsis sp. present valuable source of bio-molecules (pigments, lipids, proteins) that have nutritional potential for the prevention and treatment of human diseases. Moreover, some species of Nannochloropsis are the promising sources of biofuels and excellent candidates for the replacement of classical biofuel crops. This review describes and compares the efficiency of different conventional and novel techniques that can be used for cell disruption and recovery of bio-molecules from Nannochloropsis sp. Classification of different extraction techniques includes chemical, enzymatic, mechanical and other physical methods. The detailed analysis of extraction efficiency assisted by pressure and temperature (subcritical and supercritical fluids, hydrothermal liquefaction), ultrasound, microwaves, and pulsed electric energy (pulsed electric fields and high voltage electrical discharges) is presented. The general discussion includes comparison between techniques, their effectiveness for cell disruption and selectivity of bio-molecules extraction from Nannochloropsis sp. The cost-effectiveness, benefits and limitations of different techniques are also analyzed.

Overview on the Application of Modern Methods for the Extraction of Bioactive Compounds from Marine Macroalgae

Marine macroalgae represent a rich source of bioactive compounds that can be implemented in various food, cosmetic, and pharmaceutical products for health improvement. It has been proven that these bioactive compounds, such as polyphenols, polysaccharides, carotenoids, and ω-3 fatty acids possess bioactivity. For the extraction of these compounds, modern methods (Supercritical Fluid Extraction (SFE), Subcritical Water Extraction (SWE), Ultrasound-Assisted Extraction (UAE), and Microwave-Assisted Extraction (MAE)) have been used due to their advantages over the conventional methods. The process parameters of each method must be optimized for obtaining the extracts with the targeted bioactive compounds. In distinction from the existing reviews, the present review provides novelty with respect to: (a) presenting systematically the selected process parameters of SFE (temperature, time, pressure, use of co-solvents), SWE (temperature, time, pressure, solid-solvent ratio), UAE (temperature, time, frequency, power, solid-solvent ratio), and MAE (temperature, time, frequency, power, solvent type) applied for the extractions of marine macroalgae; (b) reporting the major groups or individual compounds extracted with their biological activities (if determined); and, (c) updating available references.