Recent advances in the combination of organic solvent-free extraction, chemical standardization, antioxidant assay, and cell culture metabolomics for functional food and its by-product

Antioxidant Properties of Postbiotics: An Overview on the Analysis and Evaluation Methods

Antioxidants found naturally in foods have a significant effect on preventing several human diseases. However, the use of synthetic antioxidants in studies has raised concerns about their potential link to liver disease and cancer. The findings show that postbiotics have the potential to act as a suitable alternative to chemical antioxidants in the food and pharmaceutical sectors. Postbiotics are bioactive compounds generated by probiotic bacteria as they ferment prebiotic fibers in the gut. These compounds can also be produced from a variety of substrates, including non-prebiotic carbohydrates such as starches and sugars, as well as proteins and organic acids, all of which probiotics utilize during the fermentation process. These are known for their antioxidant, antibacterial, anti-inflammatory, and anti-cancer properties that help improve human health. Various methodologies have been suggested to assess the antioxidant characteristics of postbiotics. While there are several techniques to evaluate the antioxidant properties of foods and their bioactive compounds, the absence of a convenient and uncomplicated method is remarkable. However, cell-based assays have become increasingly important as an intermediate method that bridges the gap between chemical experiments and in vivo research due to the limitations of in vitro and in vivo assays. This review highlights the necessity of transitioning towards more biologically relevant cell-based assays to effectively evaluate the antioxidant activity of postbiotics. These experiments are crucial for assessing the biological efficacy of dietary antioxidants. This review focuses on the latest applications of the Caco-2 cell line in the assessment of cellular antioxidant activity (CAA) and bioavailability. Understanding the impact of processing processes on the biological properties of postbiotic antioxidants can facilitate the development of new food and pharmaceutical products.

Citrus wastes as sustainable materials for active and intelligent food packaging: Current advances

Citrus fruits are one of the most popular crops in the world, and around one quarter of them are subjected to industrial processes, aiming at the production of different food products. Citrus processing generates large amounts of waste, including peels, pulp, and seeds. These materials are rich sources of polymers (e.g., pectin, cellulose, hemicellulose, lignin), phenolic compounds, and essential oils. At the same time, the development of food packaging materials using citrus waste is a highly sought strategy for food preservation, and meets the principles of circular economy. This review surveys current advances in the development of active and intelligent food packaging produced using one or more citrus waste components (polymers, phenolics extracts, and essential oils). It highlights the contribution and effects of each of these components on the properties of the developed packaging, as well as emphasizes the current state and challenges for developing citrus-based packaging. Most of the reported investigations employed citrus pectin as a base polymer to produce packaging films through the casting technique. Likewise, most of them focused on developing active materials, and fewer studies have explored the preparation of citrus waste-based intelligent materials. All studies characterized the materials developed, but only a few actually applied them to food matrices. This review is expected to encourage novel investigations that contribute to food preservation and to reduce the environmental impacts caused by discarded citrus byproducts.

Assessing and optimizing the bioactivities of diverse enzyme-derived protein hydrolysates from Porphyra yezoensis: unlocking the health potential

The interest in algae-derived bioactive compounds has grown due to their potential therapeutic efficacy against a range of diseases. These compounds, derived from proteins, exhibit diverse functions and profound pharmacological effects. Recent research has highlighted the extensive health benefits of algae-derived bioactive compounds, positioning them as potential natural antioxidants in the food, pharmaceutical, and cosmetic industries. This study focuses on extracting proteins from Porphyra yezoensis using innovative physical pre-treatment methods such as stirring, ball milling, and homogenization, under various acidic and alkaline conditions. Enzymatic hydrolysis, employing commercial enzymes at optimal temperature, pH, and enzyme-substrate ratios, produced distinct fractions according to molecular weight. Pepsin demonstrated the highest hydrolysis rate, with the fraction above 10 kDa identified as the most bioactive hydrolysate. Antioxidant activity was evaluated through DPPH, ABTS, ferrous ion chelation, and reducing power assays, demonstrating high antioxidant potential and the ability to mitigate oxidative stress. The 10 kDa fraction of pepsin hydrolysate exhibited 82.6% DPPH activity, 77.5% ABTS activity, 88.4% ferrous ion chelation activity, and higher reducing power potential (0.84 absorbance at 700 nm). Further exploration of mechanisms, amino acid profiles, and potential in vivo benefits is essential to fully exploit the medicinal potential of these algae-derived hydrolysates.

A Review: Subcritical Water Extraction of Organic Pollutants from Environmental Matrices

Most organic pollutants are serious environmental concerns globally due to their resistance to biological, chemical, and photolytic degradation. The vast array of uses of organic compounds in daily life causes a massive annual release of these substances into the air, water, and soil. Typical examples of these substances include pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Since they are persistent and hazardous in the environment, as well as bio-accumulative, sensitive and efficient extraction and detection techniques are required to estimate the level of pollution and assess the ecological consequences. A wide variety of extraction methods, including pressurized liquid extraction, microwave-assisted extraction, supercritical fluid extraction, and subcritical water extraction, have been recently used for the extraction of organic pollutants from the environment. However, subcritical water has proven to be the most effective approach for the extraction of a wide range of organic pollutants from the environment. In this review article, we provide a brief overview of the subcritical water extraction technique and its application to the extraction of PAHs, PCBs, pesticides, pharmaceuticals, and others form environmental matrices. Furthermore, we briefly discuss the influence of key extraction parameters, such as extraction time, pressure, and temperature, on extraction efficiency and recovery.

Pressurized Hot Water Extraction of Mangosteen Pericarp and Its Associated Molecular Signatures in Endothelial Cells

The mangosteen (Garcinia mangostana L.) pericarp is known to be rich in potent bioactive phytochemical compounds such as xanthones, which possess pharmacologically important antioxidant activity and beneficial cardiometabolic properties. Mangosteen pericarp is typically classified as unavoidable food waste and discarded, despite being rich in bioactive phytochemical compounds that therefore present an exciting opportunity for valorization. Thus, this study aims to extract phytochemical compounds from mangosteen pericarp using pressurized hot water extraction (PHWE) and determine its biological effects in endothelial cells using RNA sequencing. Liquid chromatography with MS/MS (LC/MSMS) and UV detection (LC/UV) was subsequently used to identify three key phytochemical compounds extracted from the mangosteen pericarp: α-Mangostin, γ-Mangostin, and Gartanin. Within the tested range of extraction temperatures by PHWE, our results demonstrated that an extraction temperature of 120 °C yielded the highest concentrations of α-Mangostin, γ-Mangostin, and Gartanin with a concomitant improvement in antioxidant capacity compared to other extraction temperatures. Using global transcriptomic profiling and bioinformatic analysis, the treatment of endothelial cells with mangosteen pericarp extracts (120 °C PHWE) for 48 h caused 408 genes to be differentially expressed. Furthermore, our results demonstrated that key biological processes related to "steroid biosynthesis and metabolism", likely involving the activation of the AMPK signaling pathway, were upregulated by mangosteen pericarp extract treatment. In conclusion, our study suggests a green extraction method to valorize phytochemical compounds from mangosteen pericarp as a natural product with potential beneficial effects on cardiometabolic health.