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The objective of this study is to evaluate the effect of either a solution of Thymus capitatus essential oil or its nanoemulsion on the quality of milk contaminated by bacteria. After 24h of S. aureus inoculation, bacterial growth reached 202×10(3)CFU/ml in the presence of the essential oil while it was limited to 132×10(3)CFU/ml when treated with nanoemulsion. The reduction of antioxidant capacity of milk treated with essential oil was higher when treated with nanoemulsion. Moreover, free essential oil was more efficient in protecting proteins from degradation than the nanoemulsion. For instance, after 24h of E. hirae contamination, 26% of the total proteins were consumed in the presence of nano-encapsulated essential oil, while only 14% of the initial content was consumed when free essential oil was added. Concerning milk acidity increase and the inhibition of peroxide production, no statistical differences have been recorded between the use of free essential oil or its nano-emulsion. In conclusion, bulk or nano-encapsulated T. capitatus essential oil preserve milk quality and can extend its shelf life.

In this study, we formulated and stabilized oil-in-water nanoemulsions using a crude extract from argan press-cake as sole emulsifier. Various extracts from argan press-cake were prepared in order to select the most surface-active one(s) foreseeing emulsions preparation. Fifty percent (v/v) ethanolic extract reduced the interfacial tension to a minimum value at both MCT oil and soybean oil interfaces (12.7 and 10.5 mN m respectively). This extract was also effective at producing fine emulsions with small droplet sizes (d < 115 nm) and good physical stability using different oils such as soybean oil, MCT oil and fish oil and at conventional homogenization conditions (100 MPa for 4 passes). On the other hand, the emulsions were very sensitive to NaCl addition (≥25 mM) and to acidic pH (<3) indicating that the main stabilization mechanism is electrostatic, likely due to the presence of surface-active compounds with ionizable groups such as saponins.

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A novel in vitro gastric device, the Gastric Digestion Simulator (GDS), was developed for the direct observation and quantitative analysis of the food digestion process in the human stomach. In addition to simulating the chemical digestion environment, this device provides a physical digestion environment comparable to that found in the stomach by simulating peristalsis, which is assumed to contribute to solid food disintegration. The GDS was successfully used to directly observe the disintegration process of Tofu (bean curd) as a typical solid food containing protein. The size distribution and protein content of Tofu particles during the digestion experiments were investigated. The results demonstrated the difference in particle disintegration between GDS and flask shaking experiments, which may be due to the lack of peristalsis in the latter case. Moreover, the size distribution of Tofu particles after the GDS experiments was affected by the physical properties of Tofu, thus revealing the usefulness of GDS for food digestion analysis.Keywords: GI tract, gastric digestion, in vitro gastric device, peristalsis, direct observation, solid food IntroductionIn the human gastrointestinal (GI) tract, foods are digested by a combination of physical and chemical processes. Chemical digestive processes are catalyzed by digestive enzymes secreted in the stomach and small intestine, and disintegrate foods down to the molecular scale. However, physical digestive processes, which are induced mainly by peristalsis, mix and empty gastric and intestinal contents, and thus play an important role in promoting food digestion in the GI tract. Peristalsis in the GI tract is caused by peristaltic wall motion (e.g., antral contraction waves (ACWs)) in the stomach. Periodically generated ACWs induce the motion of the gastric contents, mix the gastric contents, and grind bulk solid foods to reduce their particle size (Kong and Singh, 2008) Food digestion in the human GI tract has been studied using in vivo, in vitro, and in silico approaches. MRI has been used for in vivo studies on gastric peristaltic motion and the physical properties of gastric contents. The speed of ACWs and the ACW amplitude in the human stomach were calculated using data obtained by real-*To whom correspondence should be addressed. time MRI (King et al., 1984;Pallotta et al., 1998). The timedependent change of the viscosity of the gastric contents was measured using echo planar MRI (Marciani et al., 2000). This study seeks to develop a new in vitro gastric digestion device that focuses mainly on the physical digestion environment of the human stomach, and to assess the device's performance. The gastric digestion simulator (GDS) that we developed here can simulate peristaltic motion in the human stomach and enables direct observation of the digestion process in real time. In this study, two different types of Tofu were used as model solid foods.We investigated food digestion characteristics using GDS to quantitatively understand the dynamic digestion processes in t...

Eggshell has been recently introduced as a bone substitute candidate in reconstructive surgery. The aim of this experimental study study was to determine its degradation rate in both a skeletal and extraskeletal site. In experiment 1, eggshell particles with four different sizes (50, 75, 150, and 300 microns in diameter) were implanted in subcutaneous pouches of 30 rats. In experiment 2, a fragment of ostrich eggshell was implanted on the nasal dorsum of 10 rats. Animals were sacrificed at 1 (N = 10), 2 (N = 10), and 4 months (N = 10) during the first stage of the study, and at 1 year during the second stage of the study. The results were assessed by X-ray examination and routine histological techniques. In experiment 1, all animals healed uneventfully. At 1 month, only 50-micron particles had undergone resorption. At 2 months, both 50- and 75-micron particles had undergone resorption. At 4 months, the 150- and 300-micron particles were resorbed incompletely. Histologically, the eggshell elicited a mild inflammatory reaction at 1 month that decreased progressively at further stages. In experiment 2, all animals except one healed uneventfully. Radiologically, the eggshell implant displayed a noticeable stability. Histologically, seven of nine implants were encapsulated, but two of them were surrounded by a bony rim. In conclusion, eggshell is a resorbable implant, but the degradation kinetic is size dependent. Large ostrich grafts are also suitable as onlay graft, but a complementary osteosynthesis is recommended to enhance osteointegration.