Potential applications of Rhodomyrtus tomentosa leaf extract as natural anti-staphylococcal additive in food systems: Efficacy and in vivo safety evaluation.

This work aimed to explore the potential use of Rhodomyrtus tomentosa ethanol leaf extract (RTEL) as an alternative food preservative agent for controlling the growth of Staphylococcus aureus. Antibacterial activities against food-isolated S. aureus were performed using disc diffusion and broth microdilution assays, followed by evaluating in vivo subacute oral toxicity of the extract. Salad dressing was used as a food model to study bactericidal properties and consumer acceptability. RTEL remarkably inhibited S. aureus with minimum inhibitory concentrations (MICs) ranging from 7.81-62.5 µg/mL. Repeated oral doses (5, 50, and 300 mg/kg RTEL) for 28 days did not affect any of the measured toxicity parameters. The no-observed-adverse-effect-level (NOAEL) of RTEL was noted as more than 300 mg/kg body weight/day. The utilization of RTEL (12.5 mg/mL) in the vinaigrette salad dressing did not affect the consumer acceptability of the product, remarkably killed the pathogen within 3-9 h of exposure. The results indicated that RTEL is safe and effective as a natural anti-staphylococcal controlling agent that could be utilized in food systems. Further work is required on the effects of enterotoxin production, an important virulence factor of S. aureus responsible for food-borne disease.

Microencapsulation of Moringa oleifera leaf extracts with vegetable protein as wall materials.

Moringa oleifera, often referred to as 'miracle tree' contains high amount of bioactive nutrients and dietary antioxidants, which help in ameliorating oxidative stress and degenerating diseases. However, the bioactive compounds are highly susceptible to degradation, and this may decrease the antioxidants activity present in M. oleifera. To prevent these limitations, the utilisation of microencapsulation technique is of necessity. This study investigated the effect of two vegetable proteins: soy protein isolate and pea protein isolate as wall materials for M. oleifera leaf extracts encapsulation by spray drying technique. Three inlet air temperatures (140, 160, and 180 ℃) and two different formulations of core:wall material ratios (1:4 and 1:9, w/w) were studied. The total phenolic contents, antioxidant activity, microencapsulation yield, morphology, colour, tapped and bulk densities, particle size, and storage stability of M. oleifera microcapsules were analysed. Moringa microencapsulates with pea protein isolate had better powder quality than Moringa microencapsulates with soy protein isolate considering its significant higher particle size, bulk and tapped densities. Moringa microencapsulates with soy protein isolate proved to be a better carrier of bioactive compounds of both total phenolic content and 2,2-diphenyl-1-picrylhydrazyl activity at inlet air temperature in the range of 140-180 ℃. The total phenolic content and 2,2-diphenyl-1-picrylhydrazyl activity tend to be the most stable compound. The storage stability of bioactive compounds of both Moringa microencapsulates with pea protein isolate and Moringa microencapsulates with soy protein isolate was better preserved at 4 ℃ compared to that of 25 ℃.

Improved Lipid Profile Associated with Daily Consumption of Tri-Sura-Phon in Healthy Overweight Volunteers: An Open-Label, Randomized Controlled Trial.

Tri-Sura-Phon (TSP), a traditional Thai polyherbal formula renowned for its rejuvenating properties, is commonly used as a blood tonic. It comprises Cinnamomum bejolghota, Cinnamomum parthenoxylon, and Aquilaria crassna. The aim of this study is to evaluate the beneficial properties of TSP tea consumption on blood glucose regulation and serum lipid profiles of healthy overweight volunteers. This open-label, randomized controlled trial was conducted in 70 healthy overweight adults. Two groups of 35 subjects took a TSP infusion or a placebo (cornstarch) twice daily for 8 weeks. The blood glucose regulation, serum lipid profiles, BMI, and liver function tests of the subjects were determined at the baseline, 4th week, and endpoint (8th week). Significant decreases in the average fasting levels of total cholesterol (p = 0.013), triglyceride (p = 0.001), and low-density lipoprotein (LDL, p = 0.017) were observed in the TSP group at the 8th week compared to those at the baseline. The average HDL level in the TSP group at the beginning of the study was 65.2 mg/dL, and it increased significantly (p = 0.005) to 72.4 mg/dL after 8 weeks of TSP intake. This study showed that the intake of TSP tea as an antioxidant-rich beverage might be safe and improve lipid profiles in overweight adults.

Characteristics of collagens from the swim bladders of yellowfin tuna (Thunnus albacares).

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were extracted from the swim bladders of yellowfin tuna (Thunnus albacares) with yields of 1.07% and 12.10%, respectively. Based on electrophoretic patterns, both ASC and PSC consisted of two α-chains (α1 and α2) and were characterised to be type I collagen. ASC had higher ß-chains than PSC. Imino acid contents of ASC and PSC were 128 and 169 residues/1,000 residues, respectively. Fourier transform infrared (FTIR) spectra of both ASC and PSC were similar and revealed the presence of a triple helix. Both ASC and PSC had the highest solubility at acidic pHs. From zeta potential analysis, a net charge of zero was found at pH 6.05 and 5.93 for ASC and PSC, respectively. Tmax of ASC and PSC were 32.97 and 33.92°C, respectively. The swim bladders of yellowfin tuna could therefore serve as an alternative source of collagen for future applications.

Characterisation of mucilages extracted from seven Italian cultivars of flax.

The chemical composition, physicochemical, functional and sensory properties of mucilages, extracted from seven Italian flax cultivars, were evaluated. All samples were composed of neutral and acidic sugars, with a low protein content. From the NMR data, a rhamnogalacturonan backbone could be inferred as a common structural feature for all the mucilages, with some variations depending on the cultivar. All the suspensions showed a poor stability, which was consistent with a low zeta potential absolute value. The viscosity seemed to be positively correlated with the neutral sugars and negatively with the amount of proteins. Functional properties were dependent on the cultivar. The sensory analysis showed that most mucilages are tasteless. All these outcomes could support the use of flaxseed mucilages for industrial applications. In particular, Solal and Festival cultivars could be useful as thickeners, due to their high viscosity, while Natural, Valoal and Kaolin as emulsifiers for their good surface-active properties.

Effects of salting processes and time on the chemical composition, textural properties, and microstructure of cooked duck egg.

UNLABELLED: Chemical composition, textural properties, and microstructure of cooked duck egg salted by 2 methods (coating and immersing) were determined during 4 wk of salting. As the salting time increased, moisture content increased and salt content decreased for both cooked salted egg white and yolk. Oil exudation of cooked yolk and expressible water content of cooked egg white obtained from both salting methods increased as salting proceeded (P < 0.05). After cooking, oil exudation accompanied by the solubilized pigments, especially at the outer layer of yolk, was obtained. At week 3 of salting, egg yolk from coating method had the higher egg exudation than that from immersing method. As the salting times increased, the lower hardness, springiness, gumminess, chewiness, and resilience with higher adhesiveness and cohesiveness were generally found in cooked salted egg white (P < 0.05), irrespective of salting methods. Conversely, the hardness of cooked yolk increased continuously and reached the maximum at week 2 and 2 to 3 for immersing and coating method (P < 0.05), respectively. Confocal laser scanning micrographs revealed the smaller yolk granules with more release of free lipid in salted egg after heating, compared with the fresh counterpart. As visualized by scanning electron microscope, gel of cooked salted egg white was coagulum type with larger voids. Salting methods determined oil exudation in egg yolk and texture profile of egg white gel after cooking; however, those attributes were also governed by the salting time. PRACTICAL APPLICATION: Salted duck egg can be made by 2 methods (coating and immersing) affecting the characteristic of salted egg white and yolk after cooking. Desirable cooked salted egg having the red yolk with hardness and high oil exudation could be obtained when salting was carried out for 3 and 4 wk for immersing and coating method, respectively.

Protein hydrolysate of salted duck egg white as a substitute of phosphate and its effect on quality of Pacific white shrimp (Litopenaeus vannamei).

Protein hydrolysate from salted egg white (PHSEW) with different degrees of hydrolysis (DH) (3%, 6%, and 9%) was produced using pepsin. Disappearance of proteins with molecular weight (MW) of 108 and 85 kDa with the concomitant formation of proteins with MW of 23, 20, 13, and 5 kDa was observed in PHSEW. The use of PHSEW for quality improvement of Pacific white shrimp (Litopenaeus vannamei) was investigated. Shrimp soaked in 4% NaCl containing 7% PHSEW and 2.5% mixed phosphates (0.625% sodium acid pyrophosphate [SAPP] and 1.875% tetrasodium pyrophosphate [TSPP]) had the highest cooking yield with the lowest cooking loss (P < 0.05), compared with shrimps with other treatments. Nevertheless, no difference in weight gain was obtained in comparison with those treated with 4% NaCl containing 3.5% mixed phosphate (P > 0.05). Cooked shrimp treated with 4% NaCl containing 7% PHSEW and 2.5% mixed phosphate or those treated with 4% NaCl containing 3.5% mixed phosphate had the higher score of appearance, texture, and overall likeness but less shear force, in comparison with the control (no treatment) (P < 0.05). Microstructure study revealed that muscle fibers of cooked shrimp from both treatments had the swollen fibrils and gaps, while the control had the swollen compact structure. Therefore, use of PHSEW could reduce phosphate residue in shrimps without an adverse effect on sensory properties.