Decomposition of urea in aqueous solution was carried out using a microwave discharge electrodeless lamp (MDEL) consisting of two photoreactors with a triple tube structure that generate vacuum-UV/UV light and reactive oxygen species (ROS) using microwaves (MW) as an energy source. The rate of decomposition of urea was highest under acidic conditions (pH 4) compared with those at pH 7 and 10.When used in combination with dispersed TiO2, a photocatalyst, high decomposition efficiency was achieved with less power consumption. Moreover, decomposition efficiency more than two times higher than that of ozone oxidation and sodium hypochlorite oxidation could be realized.
Volatile compounds and quality changes of bitter apricot (Armeniaca sibirica L.) kernel oil (AKO) with different roasting conditions were determined. Bitter apricot kernels were roasted at 120, 130, 140 and 150°C for 15 min. Unroasted bitter apricot kernel oil was used as the control. Quality indicators included color, acid value and peroxide value, fatty acids, total phenols and oxidative stability. Peroxide values of the tested oils were 0.46-0.82 meq/kg, acid values were 0.60-1.40 mg KOH/g, and total phenol contents were 54.1-71.5 µg GAE/g. Oleic acid was the major fatty acid, followed by linoleic, palmitic, stearic and palmitoleic acids. Roasting increased the oxidative stability of bitter AKO. Volatile compounds were tentatively identified and semi-quantified. Among the 53 volatiles identified, benzaldehyde and benzyl alcohol were the major components. These two aroma compounds increased significantly during roasting and contributed sweet and almond flavors. Pyrazines were also prevalent and significantly increased with roasting. Sensory evaluation showed that roasted, nutty, sweet and oily aromas increased as roasting temperature increased.
Practical applications: Bitter apricot kernels cannot be consumed directly, thus it is potentially beneficial to find uses for them, especially in China where bitter apricot processing is a significant industry. Roasted bitter AKO with a pleasant aroma could be prepared and might find use as an edible oil. The roasting process gave the bitter AKO a pleasant flavor. This study provided preliminary information on production parameters and potential quality control parameters.
The profile and bioactivity of hops (Humulus lupulus L.) essential oil, a complex natural product extracted from cones via steam distillation, depends on genetic and environmental factors, and may also depend on extraction process. We hypothesized that compound mixtures eluted sequentially and captured at different timeframes during the steam distillation process of whole hop cones would have differential chemical and bioactivity profiles. The essential oil was collected sequentially at 8 distillation time (DT) intervals: 0-2, 2-5, 5-10, 10-30, 30-60, 60-120, 120-180, and 180-240 min. The control was a 4-h non-interrupted distillation. Nonlinear regression models described the DT and essential oil compounds relationship. Fractions yielded 0.035 to 0.313% essential oil, while control yielded 1.47%. The oil eluted during the first hour was 83.2%, 9.6% during the second hour, and only 7.2% during the second half of the distillation. Essential oil (EO) fractions had different chemical profile. Monoterpenes were eluted early, while sequiterpenes were eluted late. Myrcene and linalool were the highest in 0-2 min fraction, β-caryophyllene, β-copaene, β-farnesene, and α-humulene were highest in fractions from middle of distillation, whereas α- bergamotene, γ-muurolene, β- and α-selinene, γ- and δ-cadinene, caryophyllene oxide, humulne epoxide II, τ-cadinol, and 6-pentadecen-2-one were highest in 120-180 or 180-240 min fractions. The Gram-negative Escherichia coli was strongly inhibited by essential oil fractions from 2-5 min and 10-30 min, followed by oil fraction from 0-2 min. The strongest inhibition activity against Gram-negative Yersinia enterocolitica, and Gram-positive Clostridium perfringens, Enterococcus faecalis, and Staphylococcus aureus subs. aureus was observed with the control essential oil. This is the first study to describe significant activity of hops essential oils against Trypanosoma brucei, a parasitic protozoan that causes African trypanosomiasis (sleeping sickness in humans and nagana in other animals). Hops essential oil fractions or whole oil may be used as antimicrobial agents or for the development of new drugs.
Aroma intensities of rice are correlated with the mixture of aroma compounds it contains. 2-acetyl-1-pyrroline (2AP) has been reported as a major aroma compound and as a characteristic compound in fragrant rice. In this study, Thai local cultivars were classified into fragrant and non-fragrant rice based on the 2AP content and molecular characterization. Local rice cultivars were also examined for their proline content and volatile compounds profile, which are important factors in determining aroma. The results suggested that 43 Thai local rice cultivars were classified into 25 fragrant rice cultivars and 18 non-fragrant cultivars. The type of fragrant rice cultivars included 16 non-colored and 9 colored rice cultivars, while the type of non-fragrant rice cultivars included 14 non-colored and 4 colored rice cultivars. The proline content of local rice cultivars was determined and showed no correlation with the 2AP content; however, the proline level appears to be associated with the environmental stress in the rice cultivation area. One hundred and forty volatile compounds were identified from local rice cultivars. Among the detected compounds, 18volatile compounds, including hexanal 1-pentanol octanal (E)-2-heptenal 6-methyl-5-hepten-2-one 1-hexanol nonanal 2-butoxy-ethanol (E)-2-octenal 1-tetradecene 1-octen-3-ol decanal benzaldehyde (E)-2-nonenal 1-nonanol benzyl alcohol isovanillin and vanillin contributed to the aroma intensities of both fragrant and non-fragrant rice. Aroma compounds were more abundant in fragrant than in non-fragrant rice. Moreover, the levels of aroma compounds recorded in non-colored cultivars were higher than those in colored rice cultivars. In contrast, the 2AP content of colored rice cultivars was higher than that in noncolored rice cultivars. Our findings may assist rice breeding programs in producing a new aromatic genotype rice with high potential aroma intensities.
The structure and thermal behavior of a synthetic D-erythro-ceramide [NDS], (2S,3R)-2-octadecanoylamino-octadecane-1,3-diol (CER), molecular assembly in a UV-curable acrylic adhesive resin (acResin®) were investigated by differential scanning calorimetry (DSC), polarized-light microscopy, and X-ray diffraction (XRD). CER in the resin was found to exhibit a thermal-history-dependent polymorphic phase behavior that is similar but not identical to that observed for pure CER. The melting temperatures of the in-resin CER samples were lower than those of pure CER samples. Maintaining a melt-quenched in-resin CER sample at 60°C for 5–6 days induced a transformation from a metastable phase to a stable phase, where CER formed an ordered lamellar structure. The lamellar structure differed from that observed in the stable solid phase of pure CER samples. The findings of this study are expected to be useful for developing new medical tapes or sheets with ceramides added to the adhesives to protect skin.
The present study compared the texture, water holding capacity, and microstructure, as well as performed a particle and sensory evaluation, of soymilk-cow’s milk gels induced by acidification of a commercial starter culture with the addition of glucono-δ-lactone (GDL). Texture analysis indicated that gels made with different amounts of GDL had diverse properties. The water holding capacity (WHC) results suggested that the gels had some WHC differences. In addition, the gels with less GDL did not form a network structure. The particle size distribution of the soymilk-cow’s milk gels were approximately 3.5 μm. The sensory evaluation results were consistent with the texture properties and microstructure of the gels. This work clearly demonstrated that modulating the usage of GDL for casein and soy protein aggregation enabled the mixture of soy milk and cow’s milk to obtain a new category of milk gel products.
Generation of singlet oxygen by solar ultraviolet (UV) radiation causes acute inflammatory responses in the skin. Accumulation of singlet-oxygen-quenching antioxidants in the skin can suppress this photo-oxidative stress. This study evaluated the effect of dietary xanthophylls from red paprika fruit extract on UV-induced skin damage. A randomised double-blind placebo-controlled parallel group comparison study involving 46 healthy volunteers was performed. The minimal erythema dose (MED) of each individual was determined prior to the study. A capsule containing paprika xanthophylls (9 mg) or a placebo was administered daily for 5 weeks. The MED, minimal tanning dose (MTD), skin physiology parameters (skin color, hydration, and barrier function), and facial skin physiology parameters were evaluated at weeks 0, 2, and 4. The MED of the verum group at 2 and 4 weeks after administration was significantly higher than that of the placebo group. At 4 weeks, the suppression of UV-induced skin darkening by the verum diet was significantly greater than that of the placebo. There were no significant differences in facial skin parameters between the verum and placebo groups. Our results indicate the efficacy of dietary paprika xanthophylls in suppression of UV-induced skin damage.
Seeds oils of Phalaris canariensis extracted by ultrasonication and cold maceration were evaluated for their physical characteristics, total phenol contents, fatty acid and sterol compositions as well as for their antioxidant, antibacterial and acetylcholinesterase activities. The physicochemical properties of ultrasonication and cold maceration oils respectively were: acid values (4.00 and 3.25) mg KOH/g, peroxide values (5.53 and 4.41) meq O2 Kg–1, iodine values (88.83 and 95.17) g/100 g of oil, saponification values (119.21 and 98.17) mg KOH/g, phenolic content (36.40 and 53.00) mg GAE/g extract, chlorophylls (0.52 and 0.60) mg/kg oil and carotenoids contents (1.92 and 1.88) mg/kg oil. Gas chromatography analysis revealed that linoleic (52.03 and 52.2%), oleic (31.75 and 31.84%) and palmitic (11.09 and 11.34 %) acids were the major fatty acids in the two oils. Specific extinctions at 232 nm (K232) and 270 nm (K270) were (0.58 and 0.44) and (0.42 and 0.33), respectively. The DSC melting curve showed that their melting points and melting enthalpies were (–28.05°C and 76.8 J/g) and (–27.47°C and 62.3 J/g), respectively. On the other hand, the evaluation of their DPPH radical scavenging, total antioxidant capacity, antibacterial and acetylcholinesterase activities showed interesting results. Thus, Phalaris canariensis seeds oils could deserve further consideration and investigation as a potentially new multi-purpose product for agro-food, medicinal and cosmetic uses.
The α-form hydrated crystalline phase (often called as an α-gel) is one of the hydrated crystalline phases which can be exhibited by surfactants and lipids. In this study, a novel system of an α-form hydrated crystal was developed, composed of 3-(10-carboxydecyl)-1,1,1,3,5,5,5-heptamethyl trisiloxane (CDTS), polyoxyethylene (5 mol) glyceryl monostearate (GMS-5), higher alcohol. This is the first report to indicate that a silicone surfactant can form an α-form hydrated crystal. The physicochemical properties of this system were characterized by small and wide angle X-ray scattering (SWAXS), differential scanning calorimetry (DSC), and diffusion-ordered NMR spectroscopy (DOSY) experiments. SWAXS and DSC measurements revealed that a plurality of crystalline phases coexist in the CDTS/higher alcohol/water ternary system. By adding GMS-5 to the ternary system, however, a wide region of a single α-form hydrated crystalline phase was obtained. The self-diffusion coefficients (Dsel) from the NMR measurements suggested that all of the CDTS, GMS-5, and higher alcohol molecules were incorporated into the same α-form hydrated crystals.
Fatty acid calcium salt is a high melting point powder excellent in lubricity and water repellency and is often used as a cosmetic raw material. We have shown that several calcium salts of fatty acids have high selective bactericidal activity against Staphylococcus aureus and Propionibacterium acnes and low bactericidal activity against Staphylococcus epidermidis. In this study, we evaluated the influence of pH on the bactericidal behavior of calcium laurate, and showed that under acidic conditions it shows higher bactericidal activity against both bacteria but selectivity becomes lower. This finding is useful for designing skin cleansers and makeup cosmetics containing lauric acid.
In this study, physico-chemical properties of raw and roasted tigernut oils extracted by two different solvents were determined. Peroxide values of raw and roasted tigernut oils extracted by petroleum ether and n-hexane solvents changed between 0.83 and 0.91 meqO2/100g to 1.57 and 1.63 meqO2/100g, respectively. While oleic acid contents of raw tigernut oils extracted by petroleum ether and n-hexane are determined as 66.83 and 67.47%, oleic acid contents of roasted tigernut oils extracted by petroleum ether and n-hexane were determined as 67.08 and 68.16%, respectively. The highest δ-tocopherol content was found in raw tigernut oil extracted by petroleum ether (54.91 mg/100g), while the lowest level is determined in roasted tigernut oil by n-hexane (50.77 mg/100g). As a result, the fatty acid profiles of roasted tigernut oil extracted by n-hexane were higher compared to results of raw tigernut oils extracted by petroleum ether (p < 0.05).
The aqueous phase diagram of monohexadecyl phosphate neutralized by L-arginine (C16MP-Arg) was studied using analytical techniques including differential scanning calorimetry (DSC) and small/wide-angle X-ray scattering (SWAXS) measurements. We found that the mixture could form an α-gel over wide ranges of concentrations and temperatures. The α-gel was thermodynamically stable at 25°C (below the phase transition temperature for hexagonal or lamellar liquid crystals), and did not transform to coagel for at least one year. This behavior is unique among anionic surfactant systems. Thus, the balance between hydrophilic and hydrophobic volumes is a key factor for determining whether a stable α-gel can be obtained. In this system, the relatively large volume of Arg relaxed the alkyl chains of C16MP and prevented their crystallization.