Bioaccessibility and antioxidant activity of phenolic acids, flavonoids, and anthocyanins of encapsulated Thai rice bran extracts during in vitro gastrointestinal digestion.

Encapsulation technique was applied to improve the stability of bioactive compounds in bran extracts from Thai rice cultivars (Khao Dawk Mali 105, Kiaw Ngu, Hom Nil, and Leum Pua), using three carriers including gelatin, gum Arabic, and the mixture of gelatin and gum Arabic. The microcapsules obtained using gelatin provided a higher production yield of 76.08, 85.63, 85.63 and 85.59%, respectively. A greater encapsulation efficiency was also observed in the extracts encapsulated with gelatin (93.45, 95.91, 91.19 and 95.09%, respectively). After simulated gastric and intestinal digestion, the microcapsules formed by using gelatin exhibited the higher release of bioactive compounds and antioxidant activity than unencapsulated extracts. However, the extracts encapsulated using gelatin and gum Arabic complex yielded the lowest release of bioactive compounds and their antioxidant activity after simulated digestion. The overall results showed that gelatin was an appropriate carrier that could protect bioactive compounds from the digestion conditions.

Physicochemical stability and in vitro bioaccessibility of phenolic compounds and anthocyanins from Thai rice bran extracts.

The processing and digestive stability of ethanolic extracts from four Thai rice bran varieties, namely Khao Dawk Mali 105, Hom Nil, Kiaw Ngu, and Leum Pua, were assessed by applying different thermal and pH conditions, as well as in vitro gastrointestinal digestion models. High-performance liquid chromatography, Folin-Ciocalteu analysis, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays were used to determine the chemical composition, total phenolic content (TPC), and antioxidant activity. Thermal treatment at 100 °C for 15 min induced the degradation of phenolic components and TPC, whereas the antioxidant activities measured by DPPH and FRAP assays remained stable after the heat treatment. Higher phenolic content and antioxidant activity values were observed in the extracts incubated at acidic pH levels of 3 and 5. After simulated digestion, all extracts exhibited the decrease of phenolic compounds and anthocyanin contents, as well as antioxidant activities.

Periostin deletion suppresses late-phase response in mouse experimental allergic conjunctivitis.

BACKGROUND: To investigate the potential roles of periostin (POSTN), an extracellular matrix preferentially expressed in Th2-skewed conditions in the pathophysiology of allergic conjunctivitis. METHODS: The roles of POSTN in ragweed-induced experimental allergic conjunctivitis (RW-EAC) were evaluated using both POSTN-knockout (KO) and congenic BALB/c wild-type mice. Histological analysis was carried out to enumerate eosinophils/basophils in the conjunctival tissue. Th2 cytokine expression was evaluated by quantitative polymerase chain reaction (Q-PCR), and microarray analysis was performed to elucidate genes differentially expressed in POSTN-KO and wild-type mice in the RW-EAC model. RESULTS: Upregulation of POSTN expression and eosinophil infiltration was observed in subconjunctival tissue of RW-EAC in the wild-type mice. The number of infiltrating eosinophils in the conjunctivae of RW-EAC was diminished in POSTN-KO mice compared to wild-type mice. Q-PCR analysis of conjunctival tissue showed induction of Th2 cytokine (Ccl5, Il4, Il5, Il13) expression in the RW-EAC and attenuated Ccl5, Il4, Il13 mRNA expression in the conjunctivae of the RW-EAC using POSTN-KO mice. Microarray analysis and immunohistochemical analysis showed diminished basophil marker (Mcpt8) expression and reduced numbers of infiltrating basophils in the conjunctivae of RW-EAC in POSTN-KO mice. CONCLUSIONS: POSTN expression in conjunctival tissue plays an indispensable role in the late-phase reaction of the RW-EAC model by facilitating eosinophil/basophil infiltration and augmenting Th2 cytokine expression.

Microscopic observation and characterization of the oil bridge between dehulled-roasted sesame seeds.

The formation of an oil bridge between adhesive seeds was observed microscopically. The geometry of the oil bridge was affected by the shape of the adhesive seeds. The capillary force of the oil bridge was estimated from the image captured by the microscope. The average capillary force was 127 microN, which was five times higher than the average gravity of the seeds. It was observed that several oil bridges formed between two seeds. These results indicated an adequate ability of the seeds to adhere. The capillary force of the oil bridge increased with surface oil content. The probability of formation of an oil bridge increased with surface oil content when the surface oil content was above 0.63%. The probability of formation of an oil bridge markedly increased when sucrose was added to the seeds.

Microchannel emulsification using gelatin and surfactant-free coacervate microencapsulation.

In this study, we investigated the use of microchannel (MC) emulsifications in producing monodisperse gelatin/acacia complex coacervate microcapsules of soybean oil. This is considered to be a novel method for preparing monodisperse O/W and W/O emulsions. Generally, surfactants are necessary for MC emulsification, but they can also inhibit the coacervation process. In this study, we investigated a surfactant-free system. First, MC emulsification using gelatin was compared with that using decaglycerol monolaurate. The results demonstrated the potential use of gelatin for MC emulsification. MC emulsification experiments conducted over a range of conditions revealed that the pH of the continuous phase should be maintained above the isoelectric point of the gelatin. A high concentration of gelatin was found to inhibit the production of irregular-sized droplets. Low-bloom gelatin was found to be suitable for obtaining monodisperse emulsions. Finally, surfactant-free monodisperse droplets prepared by MC emulsification were microencapsulated with coacervate. The microcapsules produced by this technique were observed with a confocal laser scanning microscope. Average diameters of the inner cores and outer shells were 37.8 and 51.5 microm; their relative standard deviations were 4.9 and 8.4%.