Recovery of phenolic compounds of food concern from Arthrospira platensis by green extraction techniques

Exploring the Role of Phenolic Compounds in Chronic Kidney Disease: A Systematic Review

Chronic kidney disease (CKD) presents a formidable global health concern, affecting one in six adults over 25. This review explores the potential of phenolic compounds in managing CKD and its complications. By examining the existing research, we highlight their diverse biological activities and potential to combat CKD-related issues. We analyze the nutritional benefits, bioavailability, and safety profile of these compounds. While the clinical evidence is promising, preclinical studies offer valuable insights into underlying mechanisms, optimal dosages, and potential side effects. Further research is crucial to validate the therapeutic efficacy of phenolic compounds for CKD. We advocate for continued exploration of their innovative applications in food, pharmaceuticals, and nutraceuticals. This review aims to catalyze the scientific community's efforts to leverage phenolic compounds against CKD-related challenges.

High-Pressure Technologies for the Recovery of Bioactive Molecules from Agro-Industrial Waste

Large amounts of food waste are produced each year. These residues require appropriate management to reduce their environmental impact and, at the same time, economic loss. However, this waste is still rich in compounds (e.g., colorants, antioxidants, polyphenols, fatty acids, vitamins, and proteins) that can find potential applications in food, pharmaceutical, and cosmetic industries. Conventional extraction techniques suffer some drawbacks when applied to the exploitation of food residues, including large amounts of polluting solvents, increased time of extraction, possible degradation of the active molecules during extraction, low yields, and reduced extraction selectivity. For these reasons, advanced extraction techniques have emerged in order to obtain efficient residue exploitation using more sustainable processes. In particular, performing extraction under high-pressure conditions, such as supercritical fluids and pressurized liquid extraction, offers several advantages for the extraction of bioactive molecules. These include the reduced use of toxic solvents, reduced extraction time, high selectivity, and the possibility of being applied in combination in a cascade of progressive extractions. In this review, an overview of high-pressure extraction techniques related to the recovery of high added value compounds from waste generated in food industries is presented and a critical discussion of the advantages and disadvantages of each process is reported. Furthermore, the possibility of combined multi-stage extractions, as well as economic and environmental aspects, are discussed in order to provide a complete overview of the topic.

Microalgae as a Potential Functional Ingredient: Evaluation of the Phytochemical Profile, Antioxidant Activity and In-Vitro Enzymatic Inhibitory Effect of Different Species

The functional food market has been in a state of constant expansion due to the increasing awareness of the impact of the diet on human health. In the search for new natural resources that could act as a functional ingredient for the food industry, microalgae represent a promising alternative, considering their high nutritional value and biosynthesis of numerous bioactive compounds with reported biological properties. In the present work, the phytochemical profile, antioxidant activity, and enzymatic inhibitory effect aiming at different metabolic disorders (Alzheimer's disease, Type 2 diabetes, and obesity) were evaluated for the species Porphyridium purpureum, Chlorella vulgaris, Arthorspira platensis, and Nannochloropsis oculata. All the species presented bioactive diversity and important antioxidant activity, demonstrating the potential to be used as functional ingredients. Particularly, P. purpureum and N. oculata exhibited higher carotenoid and polyphenol content, which was reflected in their superior biological effects. Moreover, the species P. purpureum exhibited remarkable enzymatic inhibition for all the analyses.

Edible Seaweeds and Spirulina Extracts for Food Application: In Vitro and In Situ Evaluation of Antimicrobial Activity towards Foodborne Pathogenic Bacteria

Research is more and more focused on studying and selecting food preservatives of natural origin. In this scenario, algae are an excellent source of bioactive compounds, among which are antimicrobials, whose presence is variable depending on the algal species and environmental conditions. The aim of the present study was to obtain, by a food grade approach, antimicrobial extracts from five species already approved as foods and to test their efficacy in vitro (agar well diffusion assay) and in situ (microbial challenge test) towards foodborne pathogenic bacteria. Moreover, the total phenolic compounds of the extracts were determined in order to evaluate possible correlations with the antimicrobial activity. Strains belonging to Salmonella spp., Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus were considered. Overall, the extracts showed a good antimicrobial activity in vitro towards all the tested microorganisms, especially L. monocytogenes (15 mm of inhibition diameter). The effect of inhibition was monitored during 24, 48 and 120 h showing a good persistence in time. Arthrospira platensis exerted the highest efficacy, further revealed towards L. monocytogenes on salmon tartare as bacteriostatic using 0.45% of the extract and bactericidal using 0.90%. The presence of phenolic compounds could be related to the antimicrobial activity but was not revealed as the main component of this activity. The extract with the highest phenolic content (18.79 ± 1.90 mg GAE/g) was obtained from Himanthalia elongata. The efficacy, confirmed also in a food matrix, might open perspectives for their application as food preservative.

Evaluation of phenolic and antioxidant properties of strawberry as a function of extraction conditions

Abstract We studied the extraction of antioxidant phenolic compounds, anthocyanins and the evaluation of antioxidant activity of strawberries in different extraction conditions, varying the type of solvent (ethanol:water (50%) and acetone:water (60%), the extraction time (15 and 60 min) and the solvent volume to sample mass ratio (5 mL/g and 20 mL/g). In addition, we performed principal component analysis and cluster analysis. The results showed that, although the two solvents tested had similar influence on total phenolic compounds extraction and antioxidant activity, the 60 minutes of extraction and the use of the solvent volume/sample mass ratio of 20 mL/g were the best extraction conditions, both for the 1st and 2nd recovered extracts. However, the solvent had a marked effect on anthocyanins’ extraction, so that acetone/water extracted almost the double as compared to ethanol/water, for the same extraction conditions. Finally, factor analysis allowed identifying a grouping structure of two components, which was confirmed by the dendogram obtained from cluster analysis.

Polyphenolic Profile and Antioxidant Capacity of Extracts from Gordonia axillaris Fruits

An ultrasonic-assisted extraction (UAE) method was adopted to extract natural antioxidants from edible Gordonia axillaris fruit. Single-factor experiments and response surface methodology were conducted to investigate the influences of five different parameters on antioxidant capacity. The optimal conditions of the UAE were 39.78% ethanol, 30.94 mL/g solvent/material ratio, 59.47 min extraction time, 40 °C temperature, and 400 W ultrasonication power. The antioxidant capacity was 525.05 ± 14.34 µmol Trolox/g DW under the optimal conditions, which was in agreement with the predicted one (531.71 µmol Trolox/g DW). Additionally, in comparison with two traditional methods (maceration and Soxhlet extraction), the established UAE method greatly improved the yield of antioxidants and significantly reduced the extraction time. Besides, nine phenolic compounds were identified and quantified in the extract of Gordonia axillaris fruits by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), including rutin, gallic acid, protocatechuic acid, epicatechin, 2-hydrocinnamic acid, p-coumaric acid, quercetin, epicatechin gallate, and ferulic acid. The richness of phenolic compounds in the Gordonia axillaris fruits indicated its potential health benefits, and its extract rich in antioxidants could be developed into functional food or nutraceuticals with the potential to prevent certain diseases induced by oxidative stress, such as cardiovascular diseases and cancers. This study also provided a way to enhance the economic values of Gordonia axillaris fruits compared to raw fruits.

Mexican Microalgae Biodiversity and State-Of-The-Art Extraction Strategies to Meet Sustainable Circular Economy Challenges: High-Value Compounds and Their Applied Perspectives

In recent years, the demand for naturally derived products has hiked with enormous pressure to propose or develop state-of-the-art strategies to meet sustainable circular economy challenges. Microalgae possess the flexibility to produce a variety of high-value products of industrial interests. From pigments such as phycobilins or lutein to phycotoxins and several polyunsaturated fatty acids (PUFAs), microalgae have the potential to become the primary producers for the pharmaceutical, food, and agronomical industries. Also, microalgae require minimal resources to grow due to their autotrophic nature or by consuming waste matter, while allowing for the extraction of several valuable side products such as hydrogen gas and biodiesel in a single process, following a biorefinery agenda. From a Mexican microalgae biodiversity perspective, more than 70 different local species have been characterized and isolated, whereas, only a minimal amount has been explored to produce commercially valuable products, thus ignoring their potential as a locally available resource. In this paper, we discuss the microalgae diversity present in Mexico with their current applications and potential, while expanding on their future applications in bioengineering along with other industrial sectors. In conclusion, the use of available microalgae to produce biochemically revenuable products currently represents an untapped potential that could lead to the solution of several problems through green technologies. As such, if the social, industrial and research communities collaborate to strive towards a greener economy by preserving the existing biodiversity and optimizing the use of the currently available resources, the enrichment of our society and the solution to several environmental problems could be attained.

Influence of solvent on the yield and chemical composition of liquid products of hydrothermal liquefaction of Arthrospira platensis as revealed by Fourier transform ion cyclotron resonance mass spectrometry

Yields of liquid products (bio-oil and residual organics in aqueous solution) of hydrothermal liquefaction (at 300℃ and 60 min) of own cultivated Arthrospira platensis using different solvents have been determined. Nonpolar hexane, moderately polar dichloromethane, and relatively more polar acetonitrile have been used. High-resolution mass spectrometry based on linear quadrupole ion trap and Fourier transform mass spectrometer (LTQ FT) has been used for liquid sample characterization. Concentration of bio-oil in a unit of solvent volume after solvent extraction took the following arrangement: acetonitrile > dichloromethane > hexane. Concentration of residual organics in a unit of aqueous solution after solvent extraction took the following arrangement: hexane >dichloromethane > acetonitrile. Yield of total organics was arranged as follows: hexane > dichloromethane > acetonitrile. Content of carbon in bio-oil was increased and the content of oxygen was decreased with the increasing of solvent polarity. From mass spectrometric analysis it was established that in the positive electrospray ionization (ESI) mode the compounds containing two nitrogen atoms dominate and the considerable portion of the compounds containing single nitrogen atom are also presented for both bio-oil and residual organics samples. In the negative ESI mode the compounds containing four oxygen atoms dominated except bio-oil obtained using hexane where the compounds containing two oxygen atoms dominated. Bio-oil fraction had highly saturated compounds with low double bond equivalent values while the compounds of the residual organics fraction had large double bond equivalent values.

An innovative approach to attached cultivation of Chlorella vulgaris using different materials

This article investigates the innovative attached cultivation of Chlorella vulgaris (C. vulgaris) using different materials as an alternative to high capital techniques of harvesting such as centrifugation, flocculation, and filtration. A simple attached algal cultivation system was proposed that was equipped by 10 submerged supporting materials which can harvest algal cells, efficiently. The effect of operational parameters such as light intensity, the rate of aeration, and auto-harvesting time was investigated. A chip, durable, and abundant cellulosic material (Kaldnes carriers covered by kenafs, KCCKs) was proposed for auto-harvesting C. vulgaris cells. The results revealed that optimum aeration rate, light intensity, and auto-harvesting of microalgal cells were 3.6 vvm, 10,548 W/m², and 12 days, respectively. Six of these KCCKs had the highest biofilm formation percent up to 33%. In this condition, the rate of cell growth increased to 0.6 mg/cm². Therefore, this system can be used for appropriate auto-harvesting of microalgae in the attached growth systems. C. vulgaris biomass composition is valuable for biodiesel, bioethanol, and animal protein production.