Bioactive compounds from Cucumis melo L. fruits as potential nutraceutical food ingredients and juice processing using membrane technology.

The present study was designed to evaluate the nutritional composition of melon pulp Maazoun variety, in order to explore its potential attitude as a natural source of nutrients and bioactive molecules. The chemical characterization showed that the pulp was rich in moisture, carbohydrate, dietary fibers, and minerals, as well as carotenoids and phenolic compounds. The chromatographic analysis indicated that amentoflavone (16.14 mg/100 g) and gallic acid (13.56 mg/100 g) were the most abundant phenolic compounds. Melon flesh has an interesting volatile profile in which, mostly esters and alcohols are considered as the key odorants of this appreciated fruit. Melon juice was filtered through crossflow microfiltration that provides more translucent juice and accentuation of yellow color. During clarification process, the permeate flux was reduced by 50% in approximately 40 min. Results proved that the richness of melons in nutrients and bioactive phytochemicals makes them useful as a potential source of antioxidants and suitable as nutraceutical supplements.

Effect of xylitol chewing gum enriched with propolis on dentin remineralization in vitro.

OBJECTIVES: The aim of this study was to evaluate the efficiency of xylitol chewing gums enriched with propolis, remineralizing softly demineralized dentin in vitro. DESIGN: Four groups of chewing gum were developed; Group1: xylitol (1.8 %), Group2: xylitol + casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (3%), Group3: xylitol+Hydroxyapatite (3%) and Group4: xylitol + propolis (5%). A control group was designed without chewing gum, but with artificial saliva. Sections of embedded crowns and cleaned roots of twenty five bovine incisors were demineralized in carbonated drink. Crown specimens were half-varnished. Remineralization process was run for all the dental specimens in the 4 groups with gum extracts and in the control group with artificial saliva for 20 min at 37 °C three times a day during 7 days. Mineral contents were evaluated by scanning electron microscopy with energy dispersive X-ray spectroscopy (EDX-SEM). Surface morphology and roughness were analyzed using atomic force microscopy (AFM). Micro-hardness was measured using Vickers micro-hardness tester among varnished and unvarnished sides. RESULTS: Calcium/Phosphate mean ratio showed a significant decrease between the control group, group1, group2 and group4. Control group and group3 were not significantly different. Micro-hardness increased significantly for all treated groups. AFM showed obstruction of dentinal tubules in all the groups and roughness decreased in the treated side of the dentin compared to the untreated side for tested groups. CONCLUSION: Xylitol chewing gum enriched with propolis showed dentinal tubules occlusion, significant improvement of micro-hardness and slight decrease in roughness. Ca/P ratio analysis suggests that a mineral compound other than hydroxyapatite is responsible of tubules occlusion.

Purification and biochemical characterization of a novel thermostable protease from the oyster mushroom Pleurotus sajor-caju strain CTM10057 with industrial interest.

BACKGROUND: Proteases are hydrolytic enzymes that catalyze peptide linkage cleavage reactions at the level of proteins and peptides with different degrees of specificity. This group draws the attention of industry. More than one protease in three is a serine protease. Classically, they are active at neutral to alkaline pH. The serine proteases are researched for industrial uses, especially detergents. They are the most commercially available enzyme group in the world market. Overall, fungi produced extracellular proteases, easily separated from mycelium by filtration. RESULTS: A new basidiomycete fungus CTM10057, a hyperproducer of a novel protease (10,500 U/mL), was identified as Pleurotus sajor-caju (oyster mushroom). The enzyme, called SPPS, was purified to homogeneity by heat-treatment (80 °C for 20 min) followed by ammonium sulfate precipitation (35-55%)-dialysis, then UNO Q-6 FPLC ion-exchange chromatography and finally HPLC-ZORBAX PSM 300 HPSEC gel filtration chromatography, and submitted to biochemical characterization assays. The molecular mass was estimated to be 65 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Native-PAGE, casein-zymography, and size exclusion by HPLC. A high homology with mushroom proteases was displayed by the first 26 amino-acid residues of the NH2-terminal aminoacid sequence. Phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP) strongly inhibit SPPS, revealing that it is a member of the serine-proteases family. The pH and temperature optima were 9.5 and 70 °C, respectively. Interestingly, SPPS possesses the most elevated hydrolysis level and catalytic efficiency in comparison with SPTC, Flavourzyme® 500 L, and Thermolysin type X proteases. More remarkably, a high tolerance towards organic solvent tolerance was exhibited by SPPS, together with considerable detergent stability compared to the commercial proteases Thermolysin type X and Flavourzyme® 500 L, respectively. CONCLUSIONS: This proves the excellent proprieties characterizing SPPS, making it a potential candidate for industrial applications especially detergent formulations.

Effect of adding carob molasses on physical and nutritional quality parameters of sesame paste.

This study focused on the formulation of food products, based on sesame and carob. The possibility of developing blends from sesame paste and carob molasses, using molasses concentrations of 30, 40 and 50%, at 60, 70 and 80°Brix, respectively, has been studied. The blend prepared with 50% carob molasses at 60°Brix was found to be the most acceptable product, according to a sensory acceptability test. Sesame paste, supplemented with carob molasses, was evaluated for physical quality (oil separation, colour and texture) and nutritional composition (moisture, sugar, protein, fat, ash and polyphenols). Physical analysis showed that the addition of carob molasses to sesame paste improved its emulsion stability, changed its colour from beige to brown and modified its texture from fluid to solid. Nutritional analysis proved that mixing sesame paste with carob molasses provided a natural product, characterized by interesting nutritional value (protein: 16.97 g/100 g fry matter, fat: 12.05 g/100 g fry matter and sugar: 9.34 g/100 g fry matter), arising from the constituents of the two ingredients. Thus, the developed blend could offer a promising nutritious and healthy foodstuff to consumers.

Antihyperlipidemic and antioxidant effects of feather protein hydrolysate in high-fat diet-fed mice.

The hyperlipidemia is a serious health problem that increases the risk of many complications including cardiovascular disease. This study aims to evaluate the possible antihyperlipidemic effects of the feather protein hydrolysate (FPH) in a mice fed with a high-fat diet (HFD)-fed mice during 5 weeks. The FPH administration improved dose-dependent lipid profile, as well as the liver and renal dysfunction indices in hyperlipidemic mice. The FPH also restored the antioxidant status in liver, kidney, and heart by lowering the lipid peroxidation and enhancing the antioxidant enzymes (catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase [SOD]). Moreover, the histological studies proved that FPH administration prevents hepatic steatosis, glomerular hyperfiltration risk, and cardiac muscle hypertrophy. Accordingly, the FPH is a promising novel medicinal ingredient for possible use in the hyperlipidemic treatment and related complications.

Phytochemical profile, nutraceutical potential and functional properties of Cucumis melo L. seeds.

BACKGROUND: This study investigated the amino acids, phenolic compounds and volatile compounds in Maazoun melon seeds. The functional properties of melon seed flour, such as bulk density, swelling capacity, emulsifying capacity, and foaming capacity were also determined. RESULTS: The findings proved that the functional properties of melon seeds make them useful for incorporation into different food formulations to improve their functionality. The determination of the amino acid composition of melon seeds showed that glutamic acid (205.23 g kg-1 ), arginine (130.44 g kg-1 ), and tryptophan (129.91 g kg-1 ) were the major amino acids of the protein fraction. Chromatographic analysis indicated that phenolic acids (47.78%) constituted the main phenolic class, followed by flavonoids (27.15%). Naringenin-7-O-glycoside and gallic acid were the most abundant phenolic compounds. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses of the volatile compounds demonstrated that esters and terpenoids were the main volatile groups. The study of histological structures showed that melon seeds consist of three distinguishable parts: tegument, endosperm cells, and almond. CONCLUSION: The results obtained revealed that melon (Cucumis melo L.) seeds may be a potential source of bioactive compounds and natural substances with nutritive value and functional properties of interest to industrial applications. © 2018 Society of Chemical Industry.

Coupling xylitol with remineralizing agents improves tooth protection against demineralization but reduces antibiofilm effect.

To explore the efficiency of xylitol chewing gum enriched or not with remineralizing agents to protect tooth against cariogenic biofilm formation and demineralization. Six groups of chewing gums were prepared; Group 1: isomalt (1.8%), Group 2: casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (3%) + isomalt (1.8%), Group 3: hydroxyapatite (HAP) (2.5%) + isomalt (1.8%), Group 4: xylitol (1.8%), Group 5: CPP-ACP (3%) + xylitol (1.8%) and Group 6: HAP (2.5%) + xylitol (1.8%). The antibiofilm properties of different chewing gum extracts using seven oral bacterial species including Streptococcus mutans, Streptococcus constellatus, Streptococcus Salivarius and Streptococcus oralis were explored via the crystal violet staining assay. The remineralizing effects of those products were assessed on thirty human permanent teeth, half-protected with varnish before chemical erosion and thermocycling process with chewing gum. Remineralization was evaluated using scanning electron microscopy and microscopic measurements on polarized light microscopy. The ratio R comparing the thickness between unvarnished and varnished sides was evaluated. While the minimum biofilm inhibitory concentration (MBIC50) was low for xylitol alone compared to isomalt, it was inconsistent when enriched with remineralizing agents. The minimum biofilm eradication concentration (MBEC50) was low for xylitol groups compared to isomalt, for all the studied strains. R was significantly lower in Group 1 and Group 2, while Group 6 showed the highest ratio. Xylitol chewing gums confirmed good antibiofilm properties and showed remineralized potential on eroded teeth. When xylitol is associated to CPP-ACP or HAP, antibiofilm activity decreased while remineralization of eroded teeth increased.

Kinetic study of sulphuric acid hydrolysis of protein feathers.

Poultry feather keratin is the most important by-product from the poultry industry due to its abundance. Different methods have been still applied to process this by-product such as enzymatic hydrolysis which is expensive and inapplicable at the industrial level. This paper presents a study of acid hydrolysis of poultry feathers using different types of acids, sulphuric acid concentration, different temperatures and solid to liquid ratio to obtain a liquid product rich in peptides. The feathers analysis revealed a crude protein content of 88.83%. A maximum peptides production of 676 mg/g was reached using sulphuric acid, 1 molar acid concentration and 50 g/l solid to liquid ratio at a temperature of 90 °C after 300 min. A reaction scheme for protein aggregation and decomposition to polypeptides and amino acids was proposed and a kinetic model for peptides production was developed. The proposed kinetic model proved to be well adapted to the experimental data with R 2 = 0.99.

Effect of ultrasound-assisted osmotic dehydration pretreatment on the convective drying of strawberry.

The work was planned to produce dietetic dehydrated strawberries with application of ultrasound osmotic dehydration (UOD) as pretreatment. A Box-Behnken design (BBD) were employed to characterize the UOD strawberry process, optimize and investigate the effect of independent variables like ultrasound time (10, 20 and 30min), concentration of osmotic solution (distilled water, 32.5 and 65 °Brix) and temperature (20, 30 and 40°C) on the water loss (WL), solid gain (SG) and weight reduction (WR). The same BBD were used to estimate the main effects of OD without ultrasound treatment. A multi-criteria optimization based on maximal possible values of WL and WR and minimal value of SG was achieved. This was 20.5min of ultrasound time, 47.5 °Brix osmotic solution concentration and 31°C medium temperature. The effects of UOD carried out under the optimized operating conditions on kinetics of convective air drying of strawberry at 40, 50 and 60°C, and velocity of 1m/s, using the phenomenological model of Coupled Washing/Diffusion (CWD). Starting accessibility, moisture effective diffusivity Deff value and activation energy (Ea) were calculated from similar-Fick's law and analogous Arrhenius equation, respectively with and without shrinkage correction. Color difference, Chroma and hue angle of fresh and UOD-air dried strawberries were evaluated. Quality attributes were estimated through the assessment of the phenolic content, antioxidant activity, rehydration capacity, and X-ray powder diffraction characteristics.

Characterization, phenolic compounds and functional properties of Cucumis melo L. peels.

The aim of this work is to investigate the phytochemical composition and functional properties of the melon peels, considered as a by-product. Melon peels (maazoun cultivar) are rich in nutritional ingredients such as carbohydrates (69.77%) and ash (3.67%). They contain significant amounts of total dietary fibers (41.69%) and antioxidants as polyphenols and flavonoids (332mg/100g extract and 95.46mg/100g extract, respectively). The identification and the quantification of the phenolic compounds of melon peels were performed by high performance liquid chromatography apparatus. The obtained results indicate that hydroxybenzoic acids and flavones constitute their main phenolic classes. 3-Hydroxybenzoic acid is the major phenolic compound in the melon peels by 33.45mg/100g, followed by apigenin-7-glycoside (29.34mg/100g). Determination of the functional properties (water and oil retention capacities) and color shows that melon peels have properties that may be useful in industrial applications.