Optimizing prickly pear by-product valorization: formulating molasses with enhanced antioxidant capacities and sugar contents.

This study endeavoured to capitalize on prickly pear by-products for the optimization of molasses formulation, targeting elevated antioxidant capacities and superior sugar contents. Through robust statistical modelling, the optimal cooking parameters-temperature (70-80 °C) and duration (60-90 min)-were determined, guided by responses of antioxidant activity and Brix value. A D-Optimal mixture design further delineated the ideal proportions of molasses components (pulp, peel, and seeds). Characterization revealed that peel harboured the highest concentrations of total polyphenols (396.41 mg GAE/100g FW) and flavonoids (234.26 mg CE/100g FW), emphasizing its antioxidant potential (DPPH inhibition IC50: 12.72 µg/ml). The optimal cooking conditions were established at 78.35 °C for 79.70 min, with predictive equations guiding ingredient proportions (0.265 g pulp, 0.710 g peel, 0.025 g seed). Intriguingly, while peel inclusion enhanced total sugar content and antioxidant activity, seed incorporation exerted a contrasting effect by reducing total sugar content and limiting antioxidant activity.

Eco-friendly extraction of antibacterial compounds from enriched olive pomace: a design-of-experiments approach to sustainability.

The increasing interest in utilizing olive pomace bioactive molecules to advance functional elements and produce antioxidant and antimicrobial additives underscores the need for eco-friendly extraction and purification methods. This study aims to develop an eco-friendly extraction method to evaluate the effect of extraction parameters on the recovery of bioactive molecules from enriched olive pomace. The effects were identified based on total phenolic and flavonoid contents and antioxidant activity, employing a design of experimental methodology. The positive and the negative simultaneous effects showed that among the tested enrichments, those incorporating Nigella Sativa, dates, and coffee demonstrated superior results in terms of the measured responses. Furthermore, chromatographic analysis unveiled the existence of intriguing compounds such as hydroxytyrosol, tyrosol, and squalene in distinct proportions. Beyond this, our study delved into the structural composition of the enriched pomace through FTIR analysis, providing valuable insights into the functional groups and chemical bonds present. Concurrently, antimicrobial assays demonstrated the potent inhibitory effects of these enriched extracts against various microorganisms, underscoring their potential applications in food preservation and safety. These findings highlight enriched olive pomace as a valuable reservoir of bioactive molecules for food products since they can enhance their anti-oxidative activity and contribute to a sustainable circular economy model for olive oil industries.

Anti-Candida and Anti-Leishmanial Activities of Encapsulated Cinnamomum verum Essential Oil in Chitosan Nanoparticles.

Nanoencapsulation is widely considered as a highly effective strategy to enhance essential oils' (EO) stability by protecting them from oxidative deterioration and evaporation. The present study aims to optimize and characterize an efficient technique for encapsulating Cinnamomum (C.) verum essential oil into chitosan nanoparticles using response surface methodology (RSM). Moreover, the optimized C. verum EO nanoparticle was investigated for its antibacterial (against Gram-positive and Gram-negative bacteria), antifungal (against Candida albicans), and antiparasitic activity (against Leishmania parasites). Five parameters were investigated using a Plackett-Burman and Box-Behnken statistical design: the chitosan molecular weight, TPP concentration, C. verum EO/chitosan ratio, mixing method, and the duration of the reaction. Encapsulation efficiency and anti-candida activity were considered as responses. The antibacterial, anticandidal, and anti-leishmanial activities were also assessed using a standard micro-broth dilution assay and the cytotoxicity assay was assessed against the macrophage cell line RAW 264.7. The optimized nanoparticles were characterized using Fourier transform infrared spectroscopy, Zeta potential, and scanning electron microscopy. The study results indicated that under optimal conditions, the nanoencapsulation of C. verum EO into chitosan nanoparticles resulted in an encapsulation efficiency of 92.58%, with a regular distribution, a nanoparticle size of 480 ± 14.55 nm, and a favorable Zeta potential of 35.64 ± 1.37 mV. The optimized C. verum EO/chitosan nanoparticles showed strong antifungal activity against C. albicans pathogens (CMI = 125 µg mL-1), notable antibacterial activity against both Gram-positive and Gram-negative bacteria (ranging from 125 to 250 µg mL-1), high leishmanicidal potential against the promastigotes form of L. tropica and L. major (IC50 = 10.47 and 15.09 µg mL-1, respectively), and a four-fold cytotoxicity reduction compared to non-encapsulated essential oil. These results suggest that C. verum EO-loaded chitosan nanoparticles could be a promising delivery system for the treatment of cutaneous Candida albicans infections.

Optimization of barley flour and inulin addition for pasta formulation using mixture design approach.

The aim of the present work was to optimize the formulation of a new functional pasta containing durum wheat semolina, whole barley flour, and inulin ingredients to enhance both the technological and textural properties of this product using the mixture design approach. Optimally formulated pasta with acceptable technological and textural properties as close as possible to those of control pasta was studied. The microstructure analysis of cooked and uncooked pasta was performed. Cox response trace plots revealed that the increasing amounts of whole barley flour and durum wheat semolina resulted in an increase in the cooking quality parameters and yellowness. However, pasta firmness was negatively influenced by inulin and whole barley flour addition. The ingredient composition of the optimally formulated pasta, which leads to the best technological and textural properties, was 94.8% durum wheat semolina, 3.7% whole barley flour, and 1.5% inulin. This optimal formulation had an optimal cooking time of 335.24 s, a swelling index of 2.15%, and a cooking loss of 10.44%. The firmness values and the color parameters were also satisfactory. The microstructure of the optimally formulated cooked pasta showed the presence of few not gelatinized starch granules incorporated into the protein matrix as compared to the control pasta. PRACTICAL APPLICATION: Three ingredients, durum wheat semolina, whole barley flour, and inulin, were used for the production of new functional pasta using a mixture design approach. The obtained optimally formulated pasta, with good technological and textural properties, was rich in several dietary fibers. This allows the application of whole barley flour and inulin in the cereal industry and can be of interest to the human diet.

Gelatin-chitosan-pectin films incorporated with rosemary essential oil: Optimized formulation using mixture design and response surface methodology.

The aim of this study was to optimize the mechanical and texture properties of edible film improving its antibacterial property after adding rosemary essential oil (REO) using a Doehlert matrix. Films with the highest mechanical properties were acquired using a polymer composition of 65.2% glycerol, 24.3% gelatin, 10.0% chitosan and 0.5% pectin. This composition provided the highest elongation at break, tensile strength and texture values, which were respectively 51.60 ± 6.04%, 8.53 ± 2.36 MPa and 13.67 ± 1.43. The antibacterial activity of REO enriched films against Bacillus subtilis, Staphylococcus aureus, Enterococcus aerogenes, Enterococcus faecalis and Escherichia coli was enhanced when applying a mixture of 1.995 and 1.250 mg/g of two REO extracted from two rosemary different varieties. The structural, optical and barrier properties of the films were evaluated. To conclude, the enriched film showed potential coatings for controlling most common food borne bacteria growth during the food storage.

A new insight into highly contaminated landfill leachate treatment using Kefir grains pre-treatment combined with Ag-doped TiO2 photocatalytic process.

This study investigates the performance of the combination of biological pre-treatment with Kefir grains (KGs) and photocatalytic process using Ag-doped TiO2 nanoparticles (NPs) for the simultaneous removal of toxic pollutants from landfill leachate (LFL). After 5 days of 1% (w/v) KGs pre-treatment at 37 °C, TOC, COD, NH4+-N, and PO43- removal rates were 93, 83.33, 70 and 88.25%, respectively. The removal efficiencies were found to be 100, 94, 62.5, 53.16 and 47.52 % for Cd, Ni, Zn, Mn and Cu, respectively. The optimal conditions of Ag-doped TiO2 photocatalytic process were optimized using Box-Behnken design and response surface methodology (BBD-RSM) to enhance the quality of pre-treated LFL. Interestingly, Ag-doped TiO2 photocatalytic process increases the overall removal efficiencies to 98, 96, 85 and 93% of TOC, COD, NH4+-N, and PO43-, respectively. Furthermore, the removal efficiency of toxic heavy metals was gradually improved. In addition, KGs and Ag-doped TiO2 exhibited excellent recyclability showing the potential of combined biological/photocatalytic process to treat hazardous LFL.

Enhancement of Exochitinase Production by Bacillus licheniformis AT6 Strain and Improvement of N-Acetylglucosamine Production.

A strain producing chitinase, isolated from potato stem tissue, was identified as Bacillus licheniformis by biochemical properties and 16S RNA sequence analysis. Statistical experimental designs were used to optimize nine independent variables for chitinase production by B. licheniformis AT6 strain in submerged fermentation. Using Plackett-Burman design, (NH4)2SO4, MgSO4.7H2O, colloidal chitin, MnCl2 2H2O, and temperature were found to influence chitinase production significantly. According to Box-Behnken response surface methodology, the optimal fermentation conditions allowing maximum chitinase production were (in gram per liter): (NH4)2SO4, 7; K2HPO4, 1; NaCl, 1; MgSO4.7H2O, 0.1; yeast extract, 0.5; colloidal chitin, 7.5; MnCl2.2H2O, 0.2; temperature 35 °C; pH medium 7. The optimization strategy led to a 10-fold increase in chitinase activity (505.26 ± 22.223 mU/mL versus 50.35 ± 19.62 mU/mL for control basal medium). A major protein band with a molecular weight of 61.9 kDa corresponding to chitinase activity was clearly detected under optimized conditions. Chitinase activity produced in optimized medium mainly releases N-acetyl glucosamine (GlcNAc) monomer from colloidal chitin. This enzyme also acts as an exochitinase with ß-N-acetylglucosaminidase. These results suggest that B. licheniformis AT6 secreting exochitinase is highly efficient in GlcNAc production which could in turn be envisaged as a therapeutic agent or as a conservator against the alteration of several ailments.

Optimization of medium composition for the production of antimicrobial activity by Bacillus subtilis B38.

An antimicrobial activity produced by Bacillus subtilis B38 was found to be effective against several bacteria, including pathogenic and spoilage microorganisms such as, Listeria monocytogenes, Salmonella enteridis, and clinical isolates of methicillin-resistant Staphylococcus species. Nutrients such as carbon, nitrogen sources, and inorganic salts enhanced the production level of the antibacterial activity by B. subtilis B38. A first screening step showed that lactose, ammonium succinate, and manganese most influenced both cell growth and antibacterial activity production. These three factors varied at two levels in eight experiments using full factorial design. Results indicated that maximum cell growth (OD = 10.2) and maximum production of antibacterial activity (360 AU/mL) were obtained in a modified medium containing 1.5% (w/v) lactose, 0.15% (w/v) ammonium succinate, and 0.3 mg/L manganese. Depending on the indicator strain used, the antibacterial activity was 2- to 4-fold higher in the modified culture medium than in TSB medium under the same conditions. Thin layer chromatography-bioautography assay showed the presence of three active spots with R(f) values of 0.47, 0.7, and 0.82 in TSB medium. However, the inhibition zone of two spots (R(f) values of 0.7 and 0.82) was slightly larger in the modified medium. Moreover, a large zone of inhibition with an R(f) value of 0.3, was observed in this modified medium, instead of the spot having an R(f) value of 0.47. These results suggest that the nutrients act as environmental factors, quantitatively and qualitatively affecting the production of antibacterial compounds by B. subtilis B38.