A water-soluble polysaccharide from Anethum graveolens seeds: Structural characterization, antioxidant activity and potential use as meat preservative.

A novel water-soluble polysaccharide named AGP1 was successfully isolated from seeds of Anethum graveolens by hot water extraction and further purified by DEAE-Sepharose chromatography. AGP1 has a relative molecular weight of 2.1 104 Da determined by Ultra-high-performance liquid chromatography (UHPLC). The AGP1 characterization was investigated by chemical and instrumental analysis including gas chromatography mass spectrometry (GC-MS), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction. Results showed that AGP1 was mainly composed of glucose, galactose, mannose and arabinose in a molar percent of 54.3, 23.8, 14.7 and 7.2, respectively. The thermogravimetry analysis (TGA) and the differential scanning calorimetry (DSC) were used and showed that AGP1 has good thermal stability until 275 °C. Moreover, the purified polysaccharide demonstrated an appreciable in vitro antioxidant potential. The addition of the AGP1, particularly at 0.3% (w/w), in turkey sausages instead of ascorbic acid, as preservative, reduced the lipid peroxidation, preserved the pH and color and improved the bacterial stability during cold storage at 4 °C for 12 days. Overall, the results showed that the AGP1 deserves to be developed as functional and bioactive components for the food and nutraceutical industries.

Composition, antibacterial and antioxidant activities of Pimpinella saxifraga essential oil and application to cheese preservation as coating additive.

The effect of Pimpinella saxifraga essential oil (PSEO) addition (1-3%) in sodium alginate coating on the bacterial and oxidative stability of cheese was studied during refrigerated storage. The GC-HRMS analysis of PSEO showed that anethole, pseudoisoeugenol and p-anisaldehyde were the main components. The PSEO exhibited strong in vitro DPPH radical scavenging activity (IC50 = 6.81 µg/mL), ß-carotene bleaching inhibition (IC50 = 206 µg/mL), ferric reducing power (EC50 = 35.20 µg/mL), total antioxidant activity (213.96 ±â€¯11.12 µmol/mL α-tocopherol equivalent) and notable DNA protection potential. Additionally, PSEO displayed potent antibacterial activity against 3 Gram-positive and 3 Gram-negative bacteria (MICs = 0.78-3.12 mg/mL). The acute toxicity of PSEO was determined using mice model (LD50 = 976.2 mg/kg). The enrichment of sodium alginate coating with PSEO, particularly at 3%, improved cheese preservation by reducing the weight loss, preserving the pH and color and enhancing oxidative and bacterial stability without unpleased flavor for consumers.

Structural characterization, antioxidant and antibacterial activities of a novel polysaccharide from Periploca laevigata root barks.

A novel water-soluble polysaccharide named PLP1 was successfully isolated from root barks of Periploca laevigata by hot water extraction and further purified by DEAE-sepharose chromatography. PLP1 has a relative molar mass of 5.57 105 g/mol determined by Ultra-high performance liquid chromatography (UHPLC). The PLP1 structure was investigated by chemical and instrumental analysis including gas chromatography mass spectrometry (GC-MS), methylation analysis, Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic spectroscopy (1H NMR and 13C NMR). Results showed that PLP1 was mainly composed of glucose, galactose, mannose and glucuronic acid in a molar percent of 62.9, 19.4, 11.8 and 5.9, respectively. The backbone of PLP1 was composed of 1,3-ß-d-Glcp, 1,3,4-α-d-Glcp, 1,4-α-d-Manp, 1,6-α-d-Manp, 1,3-α-d-Galp and 1,6-ß-d-Galp. The thermogravimetry analysis (TGA) and the differential scanning calorimetry (DSC) were used and showed that PLP1 has good thermal stability under 229 °C. Moreover, the purified polysaccharide demonstrated an appreciable in vitro antioxidant potential and high antibacterial activity against several Gram (+) and Gram (-) strains. These finding suggested that PLP1 might be suitable for use as functional foods and as potential therapeutic agents.

Antioxidant, antibacterial and in vivo wound healing properties of laminaran purified from Cystoseira barbata seaweed.

Laminaran, a polysaccharide extracted from marine algae, exhibits attractive properties being non-toxic, hydrophilic and biodegradable. The aim of this study was to investigate the effectiveness of a cream based on the brown seaweed Cystoseira barbata laminaran (CBL) for healing full thickness wounds induced on rats. The antibacterial activity of CBL was evaluated against Gram positive and Gram negative bacteria and the antioxidant properties were assessed using five different assays. To highlight the healing effectiveness of CBL-based cream, the response to treatment was assessed by macroscopic, histologic and biochemical parameters and was compared to controls. CBL, recovered (7.27%) by ultrafiltration (1-10 kDa) and predominantly consisted of (1 → 3)-linked ß-d-glucopyranose residues with a small level of (1 → 6)-glycosidic bonds, showed noticeable antioxidant and antibacterial properties. The cream containing CBL as an active ingredient exerted a promoting healing effect. The wound contraction reached 98.57 ±â€¯1.31% after thirteen days of treatment. The derma in CBL treated group is properly arranged and revealed an improved collagen deposition and an increased fibroblast and vascular densities compared with the control groups. Overall, these results established, for the first time, a scientific in vivo evidence of the efficiency of CBL as a wound healing agent of interest in modern medicine.

Safer and healthier reduced nitrites turkey meat sausages using lyophilized Cystoseira barbata seaweed extract.

Background Nitrite salts are still common additives in the meat industry. The present study provides a first approach on the employment of the lyophilized aqueous extract (WE) of the Tunisian seaweed Cystoseira barbata for the quality enhancement of turkey meat sausage. Methods WE was supplemented as a natural antioxidant agent to investigate its effectiveness in delaying lipid oxidation turkey meat sausages containing reduced amounts of sodium nitrites. Results On storage day 5, all concentrations of WE (0.01-0.4 %) reduced the meat lipid oxidation by approximately 36 %, as compared to the negative control containing only 80 mg/kg of meat of sodium nitrites as antioxidant. It was noted that within 15 days of refrigerated storage, a meat system containing 80 mg/kg of meat of sodium nitrites and 0.02 % and 0.04 % of WE had similar Thiobarbituric Acid Reactive Substances (TBARS) levels (19±1.32 and 17±1.12 µmol/kg of meat, respectively), which were comparable to the positive control containing sodium nitrites (150 mg/kg of meat) and 0.045 % vitamin C (18.46±1.27 µmol/kg of meat). In-depth, the metabolomic profiling using gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-quadripole-time-of-flight-mass spectrometry (LC-QTOF-MS) analyses of the Tunisian seaweed C. barbata solvent extracts showed that the main active compounds were phenolic compounds, fatty acids and sterols. Conclusions Overall, the cold medium containing C. barbata lyophilized aqueous extrac, with strong antioxidant activity and antihypertensive properties, may open the way to the development of a natural quality enhancement strategy for new functional and ever healthier reduced nitrites meat sausages based on algae.

Enhancing colour and oxidative stabilities of reduced-nitrite turkey meat sausages during refrigerated storage using fucoxanthin purified from the Tunisian seaweed Cystoseira barbata.

The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory activity and the antioxidant properties, in vitro and in cured meat sausages containing reduced levels of sodium nitrite, of fucoxanthin extracted from the Tunisian brown seaweed Cystoseira barbata (CBFX). Results revealed that CBFX exhibited great scavenging activities against DPPH free radicals (EC50 = 136 µg/ml), peroxyl radicals in the linoleate-ß-carotene system (EC50 = 43 µg/ml) and hydroxyl radicals generated by Fenton reaction (DNA nicking assay). A considerable ferric reducing potential was also recorded for CBFX (EC50 = 34 µg/ml). It is interesting to note that CBFX was found to modulate the ACE activity, which is the key enzyme involved in the blood pressure regulation, with an EC50 of 5 µg/ml. When fucoxanthin was supplemented, the concentration of sodium nitrite added to cured turkey meat sausages was reduced from 150 to 80 ppm, coupled with the enhancement of colour and oxidative stabilities. Thus, CBFX, with noticeable antioxidant and antihyertensive effects, could be used as a natural additive in functional foods to alleviate potential human health hazards caused by carcinogenic nitrosamines formation.