Recovery of Phenolic Compounds with Antioxidant Capacity Through Solid-State Fermentation of Pistachio Green Hull

Pistachio green hull (PGH) represents the non-edible fraction obtained after the seed is harvested and is an important source of phenolic compounds. Solid-state fermentation (SSF) is a viable biotechnological and economical technique for extracting phenolic compounds. This study aimed to evaluate the SSF with Aspergillus niger GH1 to recover total phenolic compounds (TPC) with antioxidant capacity (AC) from PGH. For this, the time of higher TPC and AC (DPPH [2,2-diphenyl-1-picrylhydrazyl], ABTS [2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate)], FRAP [ferric reducing antioxidant power]) was selected. Then, moisture, inoculum concentration, and aeration rate were evaluated. A. niger GH1 was able to grow and colonize the PGH, with the higher value of TPC (23.83 mg/g of dry mass (gdm)) obtained after 24 h of culture, which significantly correlated with AC (Pearson's R = 0.69). Moisture and aeration rate were the main factors influencing TPC. The highest values for both TPC and AC were achieved in treatment 8 (60% moisture, 5 × 106 spores/mL, and 1 L/Kgwm min), resulting in a 129% and 1039% increase, respectively. Gallic acid 4-O-glucoside and geranine were identified in the PGH extracts using high-performance liquid chromatography coupled with mass spectrometry. The SSF provides eco-friendly alternatives for releasing bioactive compounds from PGH, adding value to this waste.

Evaluation of bioactivities of Pistacia vera L. hull extracts as a potential antimicrobial and antioxidant natural source

Pistacia vera L. hull, a the major byproduct of pistachio processing, is a source of functional compounds with antioxidant and antimicrobial activities. The extraction of these natural compounds from pistachio hulls and their use instead of synthetic chemicals has gained great attention. In this work, the phytochemical contents and antioxidant and antimicrobial activities of pistachio hull ethanolic (PVE) and aqueous (PVD) extracts obtained by microwave-assisted extraction (MAE) were investigated. Gallic acid (1.9 and 1.5 mg/g dw), quercetin (0.025 and 0.009 mg/g dw), total phenolic (23.3 and 14.7 mg GAE/g dw) and flavonoid (5.0 and 2.9 mg QE/g dw) contents and antioxidant activities (SC50 0.63 and 0.56 mg/mL) of PVE and PVD extracts were determined, respectively. The extracts exhibited antimicrobial effects against Enterococcus faecalis, Staphylococcus aureus, Streptococcus uberis, Bacillus cereus, and Bacillus subtilis. Minimal inhibitory concentrations (MICs, 0.8-49.0 and 9.6-82.5 mg/mL) and the minimal bactericidal concentrations (MBCs, 1.3-99.1 and 15.5-150.0 mg/mL) of PVE and PVD extracts were determined, respectively. Kill curves revealed that PVE and PVD extracts could inhibit the growth of bacteria. It was shown that PVE and PVD extracts could represent a good economical source of functional and bioactive compounds.

Betalains from Opuntia stricta peels: UPLC-MS/MS metabolites profiling, computational investigation, and potential applicability as a raw meat colorant

Given consumers', environmental and sustainability apprehensions, the meat industry investigated the natural colorant resources. As proof, betalain, Opuntia stricta peels (OSP) pigment, is premeditated in the meat industry. Here, OSP betalains were qualitatively profiled using UPLC-MS/MS, and 7 metabolites were identified: 6 betacyanins and a betaxanthin (arginine-betaxanthin). Molecular docking simulations of cyclo-Dopa-5-O-β-glucoside, as the core betacyanins structure, and the arginine-betaxanthin, displayed the lowest free energies of binding at -8.1 and -7.6 kcal/mol, respectively. These compounds inhibit the L. monocytogenes replication and transcription processes by targeting dihydrofolate reductase (DHFR). Then, OSP extracts (0.003, 0.006 and 0.012 %) were incorporated in the raw refrigerated beef meat, and compared to Allura red E129 at 0.002 % for 14 days. By the end of storage, OSP at 0.012 % decreased the chemical oxidation, enhanced the sensory traits, and improved the instrumental color. In addition, chemometrics could distinguish between all samples linking oxidative and microbiological variables to sensory/instrumental color attributes.

Chemical fingerprinting, antimicrobial, antioxidant, anti-inflammatory, and anticancer potential of greenly synthesized silver nanoparticles from pistachio (Pistacia vera) nuts and senna (Cassia angustifolia Vahl.) leaves

There is a growing interest in standardizing the biocompatible, cost-effective, and eco-friendly manufacturing techniques for metallic nanostructures due to their widespread applications in the industrial and medical sectors. In recent decades, green synthesis has been proven as the most suitable technique for synthesizing metal nanoparticles. The present research study investigates the use of Cassia angustifolia (senna) leaves and Pistacia vera (Pistachio) nuts to prepare crude aqueous extracts, ethanolic extracts, and biogenic silver nanoparticles (AgNPs). The prepared aqueous extracts were used as reducing, stabilizing, and capping agents for the production of silver nanoparticles. These AgNPs were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. The outcomes validated the formation of stable AgNPs with bioactive functional components. In vitro antibacterial, anticancer, anti-inflammatory, and antioxidant potentials were assessed by Kirby-Bauer disk diffusion test, MIC test, MBC test, MTT assay, BSA denaturation inhibition assay, and DPPH antioxidant assay, respectively. Results confirmed that the tested plant extract possesses a variety of bioactive compounds with various biological activities and is therapeutically effective. These findings verified that C. angustifolia and P. vera are promising bioresources for the synthesis of therapeutic extracts and nanostructures with commendable therapeutic potency.

Development of bioactive and environmentally friendly chitosan-based film using waste of pistachio dehulling process as a novel promising food packaging material

Chitosan films containing different amounts of pistachio hull methanol extract (PHE) (2 %, 4 %, 8 % w/v) were produced. LC-MS/MS analysis demonstrated that tannic acid (207.74 mg/g PHE), gallic acid (46.63 mg/g PHE), protocatechuic acid (27.79 mg/g PHE), quinic acid (16.41 mg/g PHE), isoquercitrin (15.2 mg/g PHE) were the most abundant phenolic compounds in PHE. The biological activity test results indicated that PHE enhanced the antioxidant and antibacterial activities of chitosan films. Chitosan-based films with 8 % PHE showed significant antimicrobial activity on all microorganisms tested. Chitosan films containing even the lowest concentration of PHE effectively inhibited DPPH free radicals, indicating a significant antioxidant activity. The increase in the amount of PHE caused a decrease in the L* value and an increase in the a* and b* values. It was found that the tensile strength and elongation at break of the films containing PHE were higher than those of the control film. Chitosan film with 4 % PHE exhibited the highest values of tensile strength (10.72 ± 1.06 MPa) and elongation at break (198.57 ± 10.34 %). FTIR analysis showed that PHE modified the intermolecular interactions in the film matrix, leading to the expansion of the CC bond and an increase in the intensity of the CO bands. Thermal analysis displayed that chitosan films incorporating PHE exhibited higher thermal stability compared to control films. PHE can be used as a bioactive supportive material in food packaging.

Combined in vitro/in silico approaches, molecular dynamics simulations and safety assessment of the multifunctional properties of thymol and carvacrol: A comparative insight

Bioactive compounds derived from medicinal plants have acquired immense attentiveness in drug discovery and development. The present study investigated in vitro and predicted in silico the antibacterial, antifungal, and antiviral properties of thymol and carvacrol, and assessed their safety. The performed microbiological assays against Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica Typhimurium revealed that the minimal inhibitory concentration values ranged from (0.078 to 0.312 mg/mL) and the minimal fungicidal concentration against Candida albicans was 0.625 mg/mL. Molecular docking simulations, stipulated that these compounds could inhibit bacterial replication and transcription functions by targeting DNA and RNA polymerases receptors with docking scores varying between (-5.1 to -6.9 kcal/mol). Studied hydroxylated monoterpenes could hinder C. albicans growth by impeding lanosterol 14α-demethylase enzyme and showed a (ΔG=-6.2 and -6.3 kcal/mol). Computational studies revealed that thymol and carvacrol could target the SARS-Cov-2 spike protein of the Omicron variant RBD domain. Molecular dynamics simulations disclosed that these compounds have a stable dynamic behavior over 100 ns as compared to remdesivir. Chemo-computational toxicity prediction using Protox II webserver indicated that thymol and carvacrol could be safely and effectively used as drug candidates to tackle bacterial, fungal, and viral infections as compared to chemical medication.

Gelatin-sodium alginate packaging film with date pits extract: An eco-friendly packaging for extending raw minced beef shelf life

Gelatin-sodium alginate-based active packaging films were formulated by including date pits extracts (DPE), as bioactive compound, in raw minced beef meat packaging. The DPE effects at 0.37, 0.75 and 1.5% (w/w, DPE/ gelatin-sodium alginate) on physical, optical, antioxidant and antibacterial properties of established films were assessed. Findings showed that film lightness decreased with the incorporation of DPE. Physical, antioxidant and anti-food-borne pathogens capacities were enhanced by increasing DPE concentration in the films. For 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), the films with 1.5% DPE had the greatest levels (94 and 88%, respectively). DPE films (1.5%) also exhibited the highest anti-Listeria moncytogenes activity, with an inhibition zone of 25 mm. Moreover, during 14 days at 4 °C, the bio-preservative impact of gelatin-sodium alginate film impregnated with DPE at three levels on microbial, chemical, and sensory characteristics of meat beef samples was evaluated. By the end of the storage, DPE at 1.5% enhanced the instrumental color, delayed chemical oxidation and improved sensory traits. By chemometric techniques (principal component analysis (PCA) and heat maps), all data allowed to obtain helpful information by segregating all the samples at each storage time. PCA and heat maps could connect oxidative chemical changes, instrumental color parameters, and microbiological properties to sensory attributes. These data offer an approach to well interpreting the sensory quality and how they are affected by chemical and microbiological changes in the studied meat samples. Our findings indicated the potential of the gelatin-sodium alginate film incorporated with DPE for enhancing meat safety and quality.

GC-MS profiling of Pistachio vera L., and effect of antioxidant and antimicrobial compounds of it's essential oil compared to chemical counterparts

All elements of the pistachio tree are considered raw pistachio by-products. The soft hull makes up the majority of these by-products. It contains proteins, fats, minerals, vitamins, phenolics contents (TPC), and antioxidants. Early smiling pistachios are one of the most important sources of pistachio contamination with aflatoxin in the garden and processing stages. The present study aimed to evaluate pistachio hull essential oil (EO) composition, and antioxidant and antimicrobial properties under in vitro conditions. TPC, antioxidant, and antimicrobial activity were measured using the Folin-Ciocalteu reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method, and serial dilution titration method, respectively. A gas chromatography system with a mass spectrometer (GC-MS) was utilized to determine the chemical components of the EO. The findings revealed that the quantity of TPC and anti-radical activity in IC50 were 245.43 mg gallic acid/mL and 206.32 µL/L, respectively. The free radical absorption activity of DPPH (%) increased with EO content. The inhibitory activity of EO on Staphylococcus aureus and Bacillus subtilis was much lower than that of streptomycin and penicillin. Aspergillus flavus was effectively inhibited by pistachio hull EO, comparable to fluconazole. The results obtained from GC-MS showed that the major compounds in pistachio hull essential oil include α-pinene (47.36%), terpinolene (10.57%), limonene (9.13%), and L-bornyl acetate (8.57%). The findings indicated that pistachio hull EO has potent antibacterial and antioxidant components and can be employed as a natural antimicrobial and antioxidant in food systems.

Multiobjective response and chemometric approaches to enhance the phytochemicals and biological activities of beetroot leaves: an unexploited organic waste

Research on medicinal plants is developing each day due to inborn phytochemicals, which can encourage the progress of novel drugs. Most plant-based phytochemicals have valuable effects on well-being. Among them, beetroot leaves (BL) are known for their therapeutic properties. Here, three solvents, namely, acetonitrile, ethanol, and water, and their combinations were developed for BL extraction and simultaneous assessment of phytochemical compounds and antioxidant and antifoodborne pathogen bacteria activities. By using the augmented simplex-centroid mixture design, 40.40% acetonitrile diluted in water at 38.74% and ethanol at 20.86% favored the recovery of 49.28 mg GAE/mL (total phenolic content (TPC)) and 0.314 mg QE/mL (total flavonoid content (TFC)), respectively. Acetonitrile diluted in water at 50% guarantees the best antioxidant activity, whereas the optimal predicted mixture for the highest antibacterial activity matches 24.58, 50.17, and 25.25% of acetonitrile, ethanol, and water, respectively. These extraction conditions ensured inhibition of Staphylococcus aureus, Salmonella enterica, and Escherichia coli, respectively, at 0.402, 0.497, and 0.207 mg/mL. Under optimized conditions, at three concentrations of BL, minimal inhibitory concentration (MIC), 2 × MIC, and 4 × MIC, a linear model was employed to investigate the inhibition behavior against the three tested bacteria. The early logarithmic growth phase of these bacteria illustrated the bactericidal effect of optimized extracted BL with a logarithmic growth phase inferior to 6 h. Therefore, BL extract at 4 × MIC, which corresponds to 1.608, 1.988, and 0.828 mg/mL, was more efficient against S. aureus, S. enterica, and E. coli.

An appealing review of industrial and nutraceutical applications of pistachio waste

Pistachio (Pistacia vera L.) is consumed in almost every part of the world enclosed in shells that are thrown out in baskets. Similarly, hulls separated from pistachio are discarded as waste in food processing industries. These waste materials contain functional constituents having immense industrial and nutraceutical applications. This review article summarizes the scientific investigations regarding the functional constituents and bioactive compounds in pistachio shells (PSs) and pistachio hulls (PHs). It also highlights the nutraceutical potential exhibited by functionally active compounds as well as their potential applications in various industries including nutraceutical, medicinal, and feed industries together with biosynthetic development of useful products and wastewater treatment. Pistachio waste (PW) comprising PS and PH is a rich source of various bioactive compounds. PS is full of lignin, cellulose, and hemicellulose. PH is an excellent source of carbohydrates (80.64 ± 0.98%) (including glucose, galactose, rhamnose, arabinose, xylose, mannose, galacturonic acid) as well as ash (6.32 ± 0.26%) and proteins (1.80 ± 0.28%) with small amounts of fats (0.04 ± 0.005%). Owing to its composition, PW can be beneficial in many nutraceuticals, including antioxidation, cytoprotection, anti-obesity, anti-diabetic, anti-melanogenesis, neuroprotection, anti-cancer, anti-mutagenesis, anti-inflammation, and anti-microbial. The waste materials have vast applications in the food industry, such as bio-preservation of oils and meat products, prevention of enzymatic browning in fruits, vegetables, and mushrooms, development of functional cereal and dairy products, production of food enzymes, emulsions, and manufacturing of biodegradable films for food packaging. The use of these waste products to develop and design novel functional foods with improved quality is important for both food industries and food sustainability.

Efficiency of Multiple Extraction Solvents on Antioxidant, Cytotoxic, and Phytotoxic Potential of Taraxacum officinale (L.) Weber ex F.H. Wigg. from Poonch Valley, Azad Kashmir, Pakistan

Background

Different parts of Taraxacum officinale (L.) were used in traditional medicine in various parts of the world for the treatment of health problems, and they possess significant biological activities. The present study aimed to estimate phytochemical and biological activities of T. officinale using different extraction solvents.

Methods

Methanolic, acetone, and n-hexane extracts of selected species were prepared, and ten secondary metabolites were examined using standard protocols. The antioxidant activity was performed using three in vitro methods, namely, DPPH assay, total reducing power (TRP) assay, and total antioxidant capacity (TAC). Toxicological analysis was done using the brine shrimp cytotoxic assay and radish seed phytotoxic assay.

Results

The T. officinale methanolic extract showed the highest phenolic (178.27 ± 17.17 mg/GAE/g) and flavonoid (18.50 ± 1.64 mg QE/g) contents. Similarly, the methanolic extract also revealed the highest DPPH activity (32.80 ± 9.66 IC₅₀), reducing potential (0.53 ± 0.02 mg/g), and TAC (19.42 ± 0.97 mg/g) as compared to the acetone and n-hexane extracts. The Pearson correlation analysis confirmed a strong positive correlation (r > 0.9) between total phenolic content (TPC), total flavonoid content (TFC), and all antioxidant assays. Furthermore, a heat map displayed the methanolic extract (red color) as a valuable source of phytochemicals and antioxidant agents. Moreover, the T. officinale methanolic extract also showed the highest (7.12 ppm) cytotoxic potential whereas both methanolic and acetone extracts were revealed as moderate phytotoxic agents when compared with the standard.

Conclusion

The T. officinale methanolic extract exhibited comparatively notable phytochemicals that are actively involved in antioxidant activities and possess toxicological properties. This upholds the folkloric use of T. officinale as a possible source to develop natural plant-based drugs. Further investigations to isolate bioactive compounds and elements and on their safety need to be conducted.

Pistachio Hull Extract as a Practical Strategy to Extend the Shelf Life of Raw Minced Beef: Chemometrics in Quality Evaluation

The agricultural processing industry produces a notable quantity of by-products rich in bioactive compounds, which can be exploited for agri-food applications. From pistachio industrial processing, pistachio's hull is one of the major by-products. This work aimed to evaluate the potential of pistachio hull, as a potential source of natural antioxidant, to preserve the meat quality. Here, we investigated the impact of aqueous pistachio hull extract (PHE) at 0.156% (PHE1), 0.312% (PHE2), and 0.625% (PHE3) on the quality of raw minced beef meat stored for 14 days at 4°C. At the end of storage, mesophilic total viable plate, psychotropic and Enterobacteriaceae counts, showed significantly lower (P < 0.05) microbial count in PHE samples. PHE3 revealed a powerful inhibitory effect on lipid/protein oxidation, and sensory characteristics were positively (P < 0.05) affected. Principal component analysis and heat map indicated complex and close synchronized relations among lipid/protein oxidation processes, microbial loads, and sensory attributes. Obtained results using univariate and multivariate statistical analysis underlined the importance of using different mathematical approaches, which are complementary to each other and could provide considerable information about the minced beef meat treated by PHE. Therefore, compared to synthetic antioxidants, PHE could be a clean-label alternative that can protect and enhance the quality of meat products.