Microfluidizing Technique Application for Algerian Cymbopogon citratus (DC.) Stapf Effects Enhanced Volatile Content, Antimicrobial, and Anti-Mycotoxigenic Properties.

Medicinal plant extracts are a promising source of bioactive minor contents. The present study aimed to evaluate the distinguished volatile content of Algerian Cymbopogon citratus (DC.) Stapf before and after the microfluidization process and their related antimicrobial and anti-mycotoxigenic impacts and changes. The GC-MS apparatus was utilized for a comparative examination of Algerian lemongrass essential oil (LGEO) with its microfluidization nanoemulsion (MF-LGEO) volatile content. The MF-LGEO was characterized using Zetasizer and an electron microscope. Cytotoxicity, antibacterial, and antifungal activities were determined for the LGEO and MF-LGEO. The result reflected changes in the content of volatiles for the MF-LGEO. The microfluidizing process enhanced the presence of compounds known for their exceptional antifungal and antibacterial properties in MF-LGEO, namely, neral, geranial, and carvacrol. However, certain terpenes, such as camphor and citronellal, were absent, while decanal, not found in the raw LGEO, was detected. The droplet diameter was 20.76 ± 0.36 nm, and the polydispersity index (PDI) was 0.179 ± 0.03. In cytotoxicity studies, LGEO showed higher activity against the HepG2 cell line than MF-LGEO. Antibacterial LGEO activity against Gram-positive bacteria recorded an inhibitory zone from 41.82 ± 2.84 mm to 58.74 ± 2.64 mm, while the zone ranged from 12.71 ± 1.38 mm to 16.54 ± 1.42 mm for Gram-negative bacteria. Antibacterial activity was enhanced to be up to 71.43 ± 2.54 nm and 31.54 ± 1.01 nm for MF-LGEO impact against Gram-positive and Gram-negative pathogens. The antifungal effect was considerable, particularly against Fusarium fungi. It reached 17.56 ± 1.01 mm and 13.04 ± 1.37 mm for LGEO and MF-LGEO application of a well-diffusion assay, respectively. The MF-LGEO was more promising in reducing mycotoxin production in simulated fungal growth media due to the changes linked to essential compounds content. The reduction ratio was 54.3% and 74.57% for total aflatoxins (AFs) and ochratoxin A (OCA) contents, respectively. These results reflect the microfluidizing improvement impact regarding the LGEO antibacterial, antifungal and anti-mycotoxigenic properties.

In-Vitro and In-Silico Investigation for the Spent-Coffee Bioactive Phenolics as a Promising Aflatoxins Production Inhibitor.

Aflatoxin, is a naturally occurring polyketide generated by Aspergillus flavus via biosynthetic pathways, including polyketide synthase (PKS) and non-ribosomal enzymes. The in vitro analysis supported by molecular dynamics (MD) techniques was used to examine the antifungal and anti-aflatoxigenic activity of spent coffee grounds (SCGs) methanol extract. The High-Performance Liquid Chromatography results revealed the presence of 15 phenolic acids and five flavonoids. (R)-(+)-Rosmarinic acid (176.43 ± 2.41 µg/g) was the predominant of the detected acids, followed by gallic acid (34.83 ± 1.05 µg/g). At the same time, apigenin-7-glucoside is the dominant flavonoid in the SCGs extract by 1717.05 ± 5.76 µg/g, and naringin (97.27 ± 1.97 µg/g) comes next. The antifungal and anti-aflatoxigenic activity of the SCGs extracts was 380 µL/mL and 460 µL/mL, respectively. The SGGs' effect of inhibiting five Aspergillus strains' growth on the agar media ranged between 12.81 ± 1.71 to 15.64 ± 1.08 mm by two diffusion assays. Molecular docking results confirmed the inhibitory action of different phenolics and flavonoids on the PKS and NPS key enzymes of the aflatoxin biosynthetic mechanism. The SCGs extract components with the highest free binding energy, naringin (-9.1 kcal/mL) and apigenin 7-glucoside (-9.1 kcal/mol), were subjected to an MD simulation study. The computational results infer the stabilizing effects on the enzymes upon ligand binding led to the impairment in its functionality. The current study represents a novel attempt to assess the anti aflatoxins mechanism of phenolics and flavonoids targeting PKS and NPS via computational approaches compared to in-vitro assays.

Spent Coffee Grounds Valorization as Bioactive Phenolic Source Acquired Antifungal, Anti-Mycotoxigenic, and Anti-Cytotoxic Activities.

Spent coffee grounds (SCGs), which constitute 75% of original coffee beans, represent an integral part of sustainability. Contamination by toxigenic fungi and their mycotoxins is a hazard that threatens food production. This investigation aimed to examine SCGs extract as antimycotic and anti-ochratoxigenic material. The SCGs were extracted in an eco-friendly way using isopropanol. Bioactive molecules of the extract were determined using the UPLC apparatus. The cytotoxicity on liver cancer cells (Hep-G2) showed moderate activity with selectivity compared with human healthy oral epithelial (OEC) cell lines but still lower than the positive control (Cisplatin). The antibacterial properties were examined against pathogenic strains, and the antifungal was examined against toxigenic fungi using two diffusion assays. Extract potency was investigated by two simulated models, a liquid medium and a food model. The results of the extract showed 15 phenolic acids and 8 flavonoids. Rosmarinic and syringic acids were the most abundant phenolic acids, while apigenin-7-glucoside, naringin, epicatechin, and catechin were the predominant flavonoids in the SCGs extract. The results reflected the degradation efficiency of the extract against the growth of Aspergillus strains. The SCGs recorded detoxification in liquid media for aflatoxins (AFs) and ochratoxin A (OCA). The incubation time of the extract within dough spiked with OCA was affected up to 2 h, where cooking was not affected. Therefore, SCGs in food products could be applied to reduce the mycotoxin contamination of raw materials to the acceptable regulated limits.

Influence of Nanoencapsulation Using High-Pressure Homogenization on the Volatile Constituents and Anticancer and Antioxidant Activities of Algerian Saccocalyx satureioides Coss. et Durieu.

The nanoencapsulation of essential oils enhances their applicability in several areas, such as pharmaceuticals and food biopreservation. This study focuses on the encapsulation of Saccocalyx satureioides Coss. et Durieu essential oil into nanoemulsions by high-pressure homogenization (HPH) and its effect on the volatile constituents and the antioxidant and anticancer activities of the essential oil. The analysis of hydrodistilled (HD) S. satureioides essential oil using gas chromatography-mass spectrometry revealed a total of 28 constituents, representing 99.80%, while only 13 constituents were identified in nanoemulsions, representing 98.65% of the total volatile material. The use of HPH led to qualitative and quantitative differences between the volatile profiles of the HD and the nanoemulsion of S. satureioides essential oil. Whereas borneol, α-terpineol, and thymol were the predominant constituents in the HD oil, carvacrol, thymol, and γ-terpinene were the major constituents in the nanoemulsion. The antioxidant activity of the S. satureioides essential oil nanoemulsion displayed was lower as compared to that of HD oil using DPPH free radical-scavenging, CUPRAC, and ABTS assays. This is consistent with the differences in total flavonoid, total phenolic, and volatiles detected in both HD oil and its nanoemulsion. Meanwhile, the cytotoxicity on liver cancer cells (Hep-G2) was stronger using nanoemulsions (106 µg/mL) than using HD oil (274.8 µg/mL).

Effect of nanoencapsulation on volatile constituents, and antioxidant and anticancer activities of Algerian Origanum glandulosum Desf. essential oil.

Nanoencapsulation is an attractive novel technique used for incorporating essential oils in food preparations and pharmaceutical formulae. This study investigated the effect of nanoencapsulation on the composition of volatile compounds, as well as the antioxidant and anticancer activities of hydrodistilled (HD) Origanum glandulosum Desf. Oil, which was encapsulated into nanocapsules via High Speed Homogenization (HSH) and into nanoemulsions through High Pressure Homogenization (HPH). Thirty-two volatile components were identified using Gas Chromatography-Mass Spectrometry analysis (GC-MS) in HD essential oil representing 99.04% of the total oil content. GC-MS analysis showed that the use of HPH to prepare nanoemulsions negatively affected the active compounds present in HD oil, particularly carvacrol and thymol, whereas the use of HSH led to significant quantitative differences in the composition of volatiles between HD oil and nanocapsules but generated the same profile. Consistent with the differences in total phenolics, total flavonoids, and volatiles identified in HD and nanoparticles, HD essential oil exhibited a higher antioxidant activity (IC50 4.22 mg/mL) than nanocapsules (IC50 57.51 mg/mL) and nanoemulsion (IC50 78.50 mg/mL), while nanocapsules showed the strongest cytotoxic effect on liver cancer cell line Hep-G2 (54.93 µg/mL) in comparison to HD oil (73.13 µg/mL) and nanoemulsions (131.6 µg/mL).

Effects of Carriers on Spray-dried Flavors and Their Functional Characteristics.

BACKGROUND AND OBJECTIVE: Encapsulation is an effective method to keep the quality of and avoid changes in flavors or essential oils due to oxidation, heating, volatilization, or chemical interactions. This study aims to microencapsulate key flavorings by traditional wall materials, namely, gum arabic (GA), maltodextrin (MD) and sodium caseinate (SC) and evaluate the effects of different wall materials on the properties of the flavor microcapsules. MATERIALS AND METHODS: The emulsions of flavor compounds (linalool, citral, orange oil, allyl caproate and isoamyl acetate) were prepared using GA, SC and MD as carriers with different concentrations and then encapsulated in powder form by a spray dryer. Physical properties, including encapsulation efficiency, viscosity, emulsion stability and moisture, were studied before and after the spray drying process. Moreover, the morphology and extent of the nonenzymatic browning (NEB) of powder particles were performed using a scanning electron microscope (SEM) and a chroma meter. The effect of encapsulation on flavor retention and chemical composition was evaluated using gas chromatography-mass spectrometry (GC-MS). RESULTS: Orange oil shows the maximum retention efficiency (84.5-97.9%), whereas isoamyl acetate is less retained during drying (44.4-72.5%) compared with other volatile compounds. Increasing the concentration of GA provides the highest retention for all aroma compounds and improves the viscosity and the emulsion stability of spray-dried powder. The presence of MD as the main encapsulating agent enables the formation of several homogeneous capsules with a good spherical shape and a smooth surface, according to SEM. The NEB is observed intensively in encapsulated samples containing citral and orange oils, whereas the least browning occurs in isoamyl acetate microcapsules. CONCLUSION: Wall material formulation affects the retention, morphology and physical properties of the encapsulated flavors, which can be used in food or nutraceutical powder premixes.

Influence of Spent Coffee Ground as Fiber Source on Chemical, Rheological and Sensory Properties of Sponge Cake.

BACKGROUND AND OBJECTIVE: Since spent coffee grounds (SCGs) represented the main by-product from instant coffee industry, the aim of the present study was to evaluate the use of these residues as functional food ingredient in sponge cake. MATERIALS AND METHODS: Baked control sample (100% wheat flour) and three supplemented blends (98% wheat flour+2% SCGs, 96% wheat flour+4% SCGs and 94% wheat flour+6% SCGs) were subjected to chemical, rheological, texture, freshness, volatile, sensory and color analysis. RESULTS: The SCGs are a promising source for dietary fiber (51.86%), protein (8.97%) and fat (13.89%) with a well-known negligible glycaemic sugar content. Supplemented sponge cake recipes with SCGs (2, 4 and 6%) reduced the degree of browning due to the lower glycaemic sugar content as well as the protein content in comparison to the control sample. A significant difference in the organoleptic properties were showed in all cake samples containing SCGs (p>0.05), which again may belong to the lower content of reduced sugars in SCGs. Volatiles extracted and identified using Solid Phase Micro-Extraction (SPME)/GC-MS have a lower content of furans, furanones and pyrazines in supplemented recipes due to the effect of lower glycemic sugar content. The higher dietary fiber content of SCGs increased volume, weight and the rheological properties of the sponge cake in addition to softened the texture. CONCLUSION: Innovative sponge cake proved to have excellent nutritional and functional properties to be used for patients with obesity related diseases.