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This study aims to introduce a new liposome to co-load Antarctic krill oil (AKO) and quercetin (QC) as a new delivery formulation to enrich the application of AKO and QC. The stability of liposomes could be increased by adding an appropriate quantity of soy lecithin (SL). Changes in the composition of the phospholipid membrane were strongly correlated with the stability and release capacity of loaded nutrients. SL2@QC/AKO-lips displayed a nearly spherical shape with higher oxidative stability and controlled the in vitro release performance of QC in simulated digestion. Moreover, in vitro studies indicated that new liposomes had no adverse effects on cell viability and could combine the physiological functions of AKO and QC to protect the HepG2 cells from oleic acid-induced steatosis and oxidative stress. The findings demonstrated that the AKO and QC co-loaded liposomes prepared with the addition of an appropriate quantity of SL had excellent loading efficiency of AKO/QC and good oxidative stability, security and functional activity.
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Euphausiacea , Liposomas , Animales , Liposomas/farmacología , Quercetina/farmacología , Ácido Oléico/farmacología , Aceites/farmacología , Estrés Oxidativo , LecitinasRESUMEN
The synthesis of metal nanomaterials is a timely topic due to their widespread use in fields such as crop protection, the environment, medicine, and engineering. Green synthesis of nanoparticles, which uses plant extracts instead of industrial chemical agents to reduce metal ions, has been developed to decrease costs, reduce pollution, and improve environmental and human health safety. In this paper, silver nanoparticles (AgNPs) were synthesized from the flower extract of Jasminum nudiflorum. The green synthesized AgNPs were characterized by UV-Vis, FTIR, XRD, SEM, and other technologies. The antifungal activity of the prepared AgNPs against Alternaria longipes was tested using the plate method, the concentration dilution method, and other methods, and the antioxidant activity of the prepared AgNPs was evaluated by DPPH and hydroxyl free scavenging methods. The results showed that AgNPs synthesized from J. nudiflorum flower extract have a face-centered cubic structure (fcc), and the average grain size of the nanoparticles is 13 nm; they are also mainly spherical in shape. Additionally, the concentration of AgNPs (ranging from 16 to 128 µg/mL) significantly inhibited the mycelial growth of A. longipes in comparison to the control. The inhibitory rate gradually increased with increasing AgNP concentration, ranging from 70.64% to 79.60% at a concentration of 128 µg/mL. The minimum inhibitory concentration was observed at 32 µg/mL. AgNPs induced overaccumulation of MDA in A. longipes, resulting in cell membrane damage and nucleic acid leakage. Moreover, the AgNPs have significant antioxidant properties, which increase with increasing concentration. The clearance rate of DPPH was 25.46 ± 0.90% when the concentration of AgNPs was 8 µg/mL, and the clearance rate of the hydroxyl radical was 28.62 ± 0.59% when the concentration of AgNPs was 128 µg/mL. Thus, the flower extract from J. nudiflorum holds potential as an environmentally friendly and green alternative for the synthesis of AgNPs, which have antifungal and antioxidant potential.
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Vitamin C (VC)-loaded oleogel (VCOG) with corn oil and monoglyceride stearate was used to replace lipid phase of margarine completely. The oxidative stability of VCOG was evaluated at 60±1°C in a lightproof oven for 18 days and the result showed that VCOG peroxide (> 6 days) and p-anisidine value (> 4 days) was significantly lower than that of bulk oil and VC-free oleogel (p < 0.05). Then, the margarine containing 79.70% VCOG (VCOGM) was in comparison with four commercial butter in sensory and physical characteristic. Results showed that firmness, solid fat content and trans fatty acid of VCOGM were in the lowest values while unsaturated fatty acid and adhesiveness of VCOGM was in the highest values. Furthermore, VCOGM presented the similar springiness, cohesiveness, gumminess, score appearance, texture, taste and overall impression to some/all commercial butters selected in this research (p > 0.05). These results implied that VC-loaded oleogel was an excellent alternative of lipid phase in margarine which confirmed by 55% "definitely buy" and 25% "try once-then decide".
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Ácido Ascórbico/química , Aceite de Maíz/química , Ácidos Grasos Insaturados/química , Margarina , Monoglicéridos/química , Estearatos/química , Mantequilla , Comportamiento del Consumidor , Ácidos Grasos Insaturados/análisis , Humanos , Compuestos Orgánicos/química , Oxidación-Reducción , Gusto , Triglicéridos/análisis , Triglicéridos/químicaRESUMEN
3-Monochloropropanediol esters (3-MCPDEs) and glycidyl esters (GEs) with high toxicity have drawn global concerns due to their widespread occurrence in refined oils and oil-based foods. The effect mechanisms of organic chlorine compound lindane, inorganic chlorine compounds tetra-n-butylammonium chloride (TBAC) and sodium chloride (NaCl) on the formation of 3-MCPDEs and GEs were investigated in model oils and chemical models at 240 °C. Results showed that 3-MCPDEs contents increased with the addition of lindane and TBAC, whereas, surprisingly, GEs presented the same tendency as the results of 3-MCPDEs. This suggested that although chlorine compounds were not involved in the formation reaction of GEs, they could also promote GEs formation. Chemical model experiments confirmed that the presence of chlorine compounds led to the transformation of GEs to 3-MCPDEs and conversely 3-MCPDEs could also transform to GEs. The latter transformation rate from 3-MCPDEs to GEs was higher than the former, which might account for the fact that chlorine compounds promoted GEs formation. Additionally, it was also observed that solid NaCl did not induce the increase of 3-MCPDEs and GEs levels in chemical models, suggesting that the chlorine in NaCl, different from lindane and TBAC, was not available for 3-MCPDEs formation. The present findings give novel insights into the interactions between 3-MCPDEs and GEs formation mechanisms, which offer the theoretical basis for efficient and simultaneous inhibition of 3-MCPDEs and GEs.
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Ésteres , Aceites de Plantas , Cloruros , Cloro , Ésteres/análisis , Ácidos Grasos/análisis , Contaminación de Alimentos/análisis , Modelos QuímicosRESUMEN
BACKGROUND: To explore the vitamin D status with its demographic and lifestyle factors including dietary, supplementation, and physical activity in 0-5 years old children. METHODS: This was a large population-based cross-sectional multicentre study in which the children were recruited from 12 Children's Health Care Centers by a stratified cluster random-sampling method in 10 cities in Jiangsu Province, China. RESULTS: A total number of 5289 children were investigated. The prevalence of vitamin D deficiency was 30.1%. The concentration of 25 hydroxyvitamin D was 64.0 (46.3-83.0) nmol mL-1 after adjustment for covariates. Children with higher risk of vitamin D deficiency were more likely to be at older age, girls, survey conducted in spring, location in southern Jiangsu province, residence in urban, outdoor activity < 2 h day-1 (all p < 0.05). Moreover, those with lower risk were more likely to be the number of parity ≥ 2 times, vitamin D supplementation from birth to 6 months, the initial time of vitamin D supplementation after birth ≤ 1 months, vitamin D and calcium supplementation in the last 3 months, and dose of vitamin D supplementation > 400 IU day-1 (all p < 0.05). Children with preferences for sweets, meat consumption > 150.0 g day-1 , milk consumption < 250 mL day-1 , time of sleeping < 10 h day-1 had higher risks of vitamin D deficiency. However, these relationships were affected by demographics. CONCLUSIONS: Vitamin D status during the first five years of life was suboptimal and was associated with demographic and lifestyle determinants including milk, meat, sweets, vitamin D and calcium supplementation, sleeping and outdoor activity.
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Deficiencia de Vitamina D , Vitamina D , Anciano , Niño , Preescolar , Estudios Transversales , Suplementos Dietéticos , Femenino , Humanos , Lactante , Recién Nacido , Estilo de Vida , Embarazo , Prevalencia , Deficiencia de Vitamina D/epidemiología , VitaminasRESUMEN
Vegetable oils are increasingly replacing animal fats in diets, but malondialdehyde (MDA), a peroxidation product of these oils, has been regarded as toxic; this necessitated investigation of MDA formation during consumption. This study investigated MDA formation in four vegetable oils during frying French fries (FF) and fried chicken breast meat (FCBM) at 180 °C for 7 h. Results showed that MDA contents were lower in oils used for frying foods than in control oils, mainly because MDA was incorporated into the foods. MDA content was lower in FF, but higher in FCBM, due to the different food components. Model oil and food system analyses yielded similar results. MDA bound the hydrophobic helical structure in starch-based FF, but was exhibited greater reactivity with nucleophilic groups in protein-based FCBM, resulting in stronger interaction with FCBM than with FF. Our results indicated the existence of distinct mechanisms underlying MDA migration in different food matrixes.
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Culinaria/métodos , Lípidos/química , Malondialdehído/química , Aceites de Plantas/química , Adsorción , Animales , Pollos , Análisis de los Alimentos/métodos , Calor , Interacciones Hidrofóbicas e Hidrofílicas , Carne/análisis , Solanum tuberosum/química , Solanum tuberosum/metabolismo , Almidón/químicaRESUMEN
BACKGROUND: Glycidyl esters (GEs) have attracted worldwide attention for their potential harm to human health. The GEs in edible oils mainly form during the deodorization of the oil refining processes. We used sesamol and sesamolin to inhibit the formation of GEs in model corn oil (MCO), model palm oil (MPO) and model rice bran oil (MRO) during a deodorization process. RESULTS: The results showed that, in the three model oils, the total GE content was in the following order from highest to lowest: MRO (1437.98 µg kg-1 ) > MPO (388.64 µg kg-1 ) > MCO (314.81 µg kg-1 ). The inhibitory effect of the three antioxidants on the formation of GEs in the MCO was in the following order from strongest to weakest: tert-butylhydroquinone (TBHQ) > sesamol > sesamolin. CONCLUSION: When the mass percentage of sesamol was 0.05%, its inhibition percentage on GEs was close to the inhibition percentage of 0.02% added TBHQ. The present study provides a foundation for understanding how to inhibit the formation of GEs in oils by adding sesamol during the deodorization process.
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Benzodioxoles/análisis , Dioxoles/análisis , Compuestos Epoxi/química , Fenoles/análisis , Aceites de Plantas/química , Antioxidantes/análisis , Color , Aditivos Alimentarios/química , Manipulación de Alimentos , Calor , Oxidación-Reducción , Aceite de Palma/químicaRESUMEN
A kinetic model for glycidyl ester (GE) formation in both palm oil and chemical models during high-temperature heating was built to investigate the formation and degradation mechanisms of GEs in refined palm oil. The results showed that the formation and degradation of GEs followed pseudo-first-order reactions, and the rate constants of reaction kinetics followed the Arrhenius equation. The estimated activation energy of the GE degradation reaction (12.87 kJ/mol) was significantly lower than that of the GE formation reaction (34.58 kJ/mol), suggesting that GE degradation occurred more readily than formation. The Fourier transform infrared (FTIR) band intensities of epoxy and ester carboxyl groups decreased over heating time, while no band assigned to the cyclic acyloxonium group was found. Furthermore, no 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-cyclic acyloxonium radical adduct was detected by quadrupole time-of-flight mass spectrometry (Q-TOF-MS). The above findings indicated that GEs were decomposed, fatty acid was also liberated, and GE degradation did not involve a cyclic acyloxonium intermediate. GEs were primarily decomposed into monoacylglycerol via ring-opening reaction during heating followed by fatty acid and glycerol via hydrolysis reaction.
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Compuestos Epoxi/química , Aceite de Palma/química , Culinaria , Calor , Cinética , Modelos Químicos , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Vitamin C (VC) is widely used as an antioxidant and nutrient to increase the nutritional value and shelf-life of foods. In this article, VC was loaded in oleogels using a simple two-step emulsion-templated approach and the effects of oil type (linseed oil, corn oil, and camellia oil) and crystallization temperature (Tc, -18, 0, 5, and 25 °C) on the physical properties, VC concentration, and oxidation stability of the VC-loaded oleogels were studied. As the amount of saturated fatty acids in the oil phase of the oleogels decreased, the VC loading level, oxidation stability and physical properties of the corn-oil-based oleogel (COG) were better than those of camellia-oil-based oleogels and linseed-oil-based oleogels. At different Tc values, the temperature and frequency dependent storage modulus values for the COG crystallized at 0 °C and 5 °C were not significantly different (P > 0.05), but their values were higher than those for COG crystallized at -18 °C and 25 °C (P < 0.05); the firmness of the COG crystallized at -18 °C and 0 °C was higher than those crystallized at 5 °C and 25 °C (P < 0.05); the network of the COG crystallized at 0 °C was denser than those of the COG crystallized at -18 °C, 5 °C, and 25 °C; and the VC concentration of the oleogels was affected by the crystallization temperature (Tc) and temperature fluctuations. To sum up, a VC-loaded oleogel with excellent mechanical properties was prepared using corn oil and crystallized at 0 °C via an emulsion-templated approach.
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Ácido Ascórbico/química , Cristalización , Geles/química , Fenómenos Físicos , Aceite de Maíz , Emulsiones , Ácidos Grasos/química , Compuestos Orgánicos , Aceites de Plantas/química , Reología , TemperaturaRESUMEN
The formation of 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE) in vegetable oils and model oil systems were quantitatively assessed by RP-HPLC. Regardless of heating temperature, HHE was only detected in rapeseed and linseed oil, while HNE was detected in all tested oils. Intrinsic tocopherols suppressed HHE/HNE formation, but with similar inhibition rates (10.49-16.04%). Linear correlations were observed between HHE/HNE contents and corresponding n-3/6 fatty acid content in oils (R2 = 0.989/0.971). Model oil system revealed that HHE/HNE formation was closely related to methyl linolenate (MLN) and methyl linoleate (ML) contents. Low levels of ML (<0.5%) and MLN (<1.0%) did not lead to HHE/HNE formation. Therefore, HHE/HNE was classified as the characteristic aldehydes of n-3 and n-6 type oils, respectively. Heat map evaluation and regression analysis indicated HHE could predict the n-3 type oils oxidation, while HNE was a good indicator to estimate the oxidative deterioration of n-6 and n-9 type oils.
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Aldehídos/química , Grasas Insaturadas/química , Aceites de Plantas/química , Cromatografía Líquida de Alta Presión , Ácidos Grasos/química , Calor , Oxidación-Reducción , Tocoferoles/químicaRESUMEN
In this study, the formation of two toxic reactive aldehydes, 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE), was investigated during frying of two different foodstuffs at 180 °C for 7 h in three different vegetable oils. The results showed that HHE and HNE content in the oil after frying was lower than that in the oil fried without foods. It was mainly because of the incorporation of HHE/HNE into the fried foods. In French Fries (FF), the HNE content was higher, whereas it was lower in the fried chicken breast meat (FCBM). The bidirectional model systems consisting of the model oil frying system and the model food frying system were used. The result of the model oil system showed that the content of HNE was higher in FF for the higher hydrophobic property than that in HHE, which would be preferably bounded into the hydrophobic helical structures, whereas the lower content of HNE was observed in FCBM due to its higher reactivity towards the nucleophilic group, namely, the protein in FCBM. Furthermore, the model food frying system including starch and protein extracted from the corresponding foodstuffs verified the results in the model oil system. Finally, the probable migration mechanism of HHE and HNE in different food matrices was proposed for the first time.
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Aldehídos/análisis , Carne/análisis , Solanum tuberosum/química , Animales , Pollos , Culinaria , Aceites de Plantas/químicaRESUMEN
This manuscript described the preparation of triglycerides with palmitic and ethyl oleate chains, and the stability of emulsions prepared from those triglycerides. Results showed that ratios of total saturated fatty acids (ΣSFA) of palm stearin oil (PSO), physical fractionation oil of palm stearin oil (PPP) and structured lipids of rich 1,3-dioleoyl-2-palmitoylglycerol (OPO) were 72.5%, 95.4% and 33.2% respectively. Rich 1,3-dioleoyl-2 palmitoylglycerol-emulsion (OPO-E) showed a better emulsion stability than that of palm stearin oil (PSO) and physical fractionation oil of palm stearin oil (PPP). The emulsion stability of OPO-E with 10% structured lipids of rich 1,3-dioleoyl-2-palmitoylglycerol (OPO) showed the highest value compared with 5% and 20% OPO. The value of emulsion stability (ES) was 85.5, the values of volume-surface mean diameter(d32) and weight mean diameter(d43) were 0.09-0.79 µm and 1.1-34.1 µm, respectively. The experimental data had significant (p < 0.05) difference with other emulsions. The value of zeta potential ranged from -34.8 to -53.1 mV, indicating that the emulsion stability of 10% OPO was the most stable in all experiment samples.
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Ácidos Grasos/química , Aceite de Palma/química , Triglicéridos/química , Fraccionamiento Químico , Estabilidad de Medicamentos , EmulsionesRESUMEN
A group of toxic aldehydes such as, malondialdehyde (MDA), 4-hydroxy-2-hexenal (HHE), and 4-hydroxy-2-nonenal (HNE) have been found in various vegetable oils and oil-based foods. Then simultaneous determination of them holds a great need in both the oil chemistry field and food field. In the present study, a simple and efficient analytical method was successfully developed for the simultaneous separation and detection of MDA, HHE, and HNE in vegetable oils by reversed-phase-high-performance liquid chromatography (RP-HPLC) coupled with photodiode array detector (PAD) at dual-channel detection mode. The effect of various experimental factors on the extraction performance, such as coextraction solvent system, butylated hydroxytoluene addition, and trichloroacetic acid addition were systematically investigated. Results showed that the linear ranges were 0.02-10.00 µg/mL for MDA, 0.02-4.00 µg/mL for HHE, and 0.03-4.00 µg/mL for HNE with the satisfactory correlation coefficient of >0.999 for all detected aldehydes. The limit of detection (LOD) and limit of quantification (LOQ) of MDA, HHE, and HNE were â¼0.021and 0.020 µg/mL, â¼0.009 and 0.020 µg/mL, and â¼0.014 and 0.030 µg/mL, respectively. Their recoveries were 99.64-102.18%, 102.34-104.61%, and 98.87-103.04% for rapeseed oil and 96.38-98.05%, 96.19-101.34%, and 96.86-99.04% for French fries, separately. Under the selected conditions, the developed methods was successfully applied to the simultaneous determination of MDA, HHE, and HNE in different tested vegetable oils. The results indicated that this method could be employed for the quality assessment of vegetable oils.
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Aldehídos/análisis , Cromatografía de Fase Inversa/métodos , Malondialdehído/análisis , Aceites de Plantas/análisis , Cromatografía Líquida de Alta Presión/métodosRESUMEN
Acid-washed oil palm wood-based activated carbon (OPAC) has been investigated for its potential application as a promising adsorbent in the removal of glycidyl esters (GEs) from both palm oil and oil model (hexadecane) solution. It was observed that the removal rate of GEs in palm oil was up to >95%, which was significantly higher than other adsorbents used in this study. In batch adsorption system, the adsorption efficiency and performance of acid-washed OPAC were evaluated as a function of several experimental parameters such as contact time, initial glycidyl palmitate (PGE) concentration, adsorbent dose, and temperature. The Langmuir, Freundlich, and Dubinin-Radushkevich models were used to describe the adsorption equilibrium isotherm, and the equilibrium data were fitted best by the Langmuir model. The maximum adsorption capacity of acid-washed OPAC was found to be 36.23 mg/g by using the Langmuir model. The thermodynamic analysis indicated that the adsorption of PGE on acid-washed OPAC was an endothermic and physical process in nature. The experimental data were fitted by using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. It was found that the kinetic of PGE adsorption onto acid-washed OPAC followed well the pseudo-second-order model for various initial PGE concentrations and the adsorption process was controlled by both film diffusion and intraparticle diffusion. The desorption test indicated the removal of GEs from palm oil was attributed to not only the adsorption of GEs on acid-washed OPAC, but also the degradation of GEs adsorbed at activated sites with acidic character. Furthermore, no significant difference between before and after PGE adsorption in oil quality was observed.
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Carbón Orgánico/química , Compuestos Epoxi/química , Aceite de Palma/química , Madera/química , Difusión , Cinética , Termodinámica , Contaminantes Químicos del Agua/químicaRESUMEN
This research investigated the effects of Fe3+ and antioxidants on the formation of glycidyl esters (GEs) and the free radical mediated mechanisms involving the recognition of cyclic acyloxonium free radical intermediate (CAFRI) for GE formation in both the plant oil model (palm oil, camellia oil, soybean oil, and linseed oil) system and the chemical model (dipalmitin and methyl linoleate) system heated at 200 °C. Results show that Fe3+ can promote the formation of GEs, which can be inhibited by antioxidants in plant oil during high-temperature exposure. Based on the monitoring of cyclic acyloxonium and ester carbonyl group by Fourier transform infrared spectroscopy, the promotion of Fe3+ and the inhibition of antioxidants (tert-butylhydroquinone and α-tocopherol) for GE formation occurred not only through lipid oxidation but also through directly affecting the formation of cyclic acyloxonium intermediate. Additionally, a quadrupole time-of-flight tandem mass spectrometry measurement was conducted to identify the presence of radical adduct captured by 5,5-dimethylpyrroline N-oxide, which provided strong evidence for the formation of CAFRI. Thus, one possible influencing mechanism can be that free radical generated in lipid oxidation may be transferred to dipalmitin and promote CAFRI formation. Fe3+ can catalyze free radical generation while antioxidants can scavenge free radical, and therefore they also can directly affect CAFRI formation.
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Antioxidantes/química , Compuestos Epoxi/química , Compuestos Férricos/química , Aceites de Plantas/química , Culinaria , Radicales Libres/química , Calor , Oxidación-Reducción , Espectroscopía Infrarroja por Transformada de Fourier , TemperaturaRESUMEN
In the present study, the formation mechanisms of glycidyl fatty acid esters (GEs) were investigated both in real edible oils (soybean oil, camellia oil, and palm oil) during laboratory-scale preparation and refining and in chemical model (1,2-dipalmitin (DPG) and 1-monopalmitin (MPG)) during high temperature exposure (160-260 °C under nitrogen). The formation process of GEs in the chemical model was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The results showed that the roasting and pressing process could produce certain amounts of GEs that were much lower than that produced in the deodorization process. GE contents in edible oils increased continuously and significantly with increasing deodorization time below 200 °C. However, when the temperature exceeded 200 °C, GE contents sharply increased in 1-2 h followed by a gradual decrease, which could verify a simultaneous formation and degradation of GEs at high temperature. In addition, it was also found that the presence of acylglycerol (DAGs and MAGs) could significantly increase the formation yield of GEs both in real edible oils and in chemical model. Compared with DAGs, moreover, MAGs displayed a higher formation capacity but substantially lower contribution to GE formation due to their low contents in edible oils. In situ ATR-FTIR spectroscopic evidence showed that cyclic acyloxonium ion intermediate was formed during GE formation derived from DPG and MPG in chemical model heated at 200 °C.
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Ésteres/química , Ácidos Grasos/química , Aceites de Plantas/química , Culinaria , Calor , Modelos Químicos , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Moderate and high microfluidization pressures (60 and 120 MPa) and different treatment times (once and twice) were used to investigate the effect of high-pressure microfluidization (HPM) treatment on the crystallization behavior and physical properties of binary mixtures of palm stearin (PS) and palm olein (PO). The polarized light microscopy (PLM), texture analyzer, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques were applied to analyze the changes in crystal network structure, hardness, polymorphism and thermal property of the control and treated blends. PLM results showed that HPM caused significant reductions in maximum crystal diameter in all treated blends, and thus led to changes in the crystal network structure, and finally caused higher hardness in than the control blends. The XRD study demonstrated that HPM altered crystalline polymorphism. The HPM-treated blends showed a predominance of the more stable ß' form, which is of more interest for food applications, while the control blend had more α- and ß-form. This result was further confirmed by DSC observations. These changes in crystallization behavior indicated that HPM treatment was more likely to modify the crystallization processes and nucleation mechanisms.
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Ácidos Oléicos/química , Aceites de Plantas/química , Ácidos Esteáricos/química , Rastreo Diferencial de Calorimetría , Cristalización , Cristalografía por Rayos X , Dureza , Técnicas Analíticas Microfluídicas , Microscopía de Polarización , Aceite de Palma , PresiónRESUMEN
KEY MESSAGE: Atkin - 1 , the only Kinesin-1 member of Arabidopsis thaliana , plays a role during female gametogenesis through regulation of nuclear division cycles. Kinesins are microtubule-dependent motor proteins found in eukaryotic organisms. They constitute a superfamily that can be further classified into at least 14 families. In the Kinesin-1 family, members from animal and fungi play roles in long-distance transport of organelles and vesicles. Although Kinesin-1-like sequences have been identified in higher plants, little is known about their function in plant cells, other than in a recently identified Kinesin-1-like protein in a rice pollen semi-sterile mutant. In this study, the gene encoding the only Kinesin-1 member in Arabidopsis, AtKin-1 was found to be specifically expressed in ovules and anthers. AtKin-1 loss-of-function mutants showed substantially aborted ovules in siliques, and this finding was supported by complementation testing. Reciprocal crossing between mutant and wild-type plants indicated that a defect in AtKin-1 results in partially aborted megagametophytes, with no observable effects on pollen fertility. Further observation of ovule development in the mutant pistils indicated that the enlargement of the megaspore was blocked and nuclear division arrested at the one-nucleate stage during embryo sac formation. Our data suggest that AtKin-1 plays a role in the nuclear division cycles during megagametogenesis.
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Arabidopsis/genética , División del Núcleo Celular/genética , Gametogénesis en la Planta/genética , Cinesinas/genética , Secuencia de Aminoácidos , Arabidopsis/citología , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Secuencia de Bases , Flores/genética , Genes Reporteros , Genotipo , Cinesinas/metabolismo , Datos de Secuencia Molecular , Mutagénesis Insercional , Especificidad de Órganos , Óvulo Vegetal/genética , Fenotipo , Filogenia , Polen/genética , Regiones Promotoras Genéticas/genética , Alineación de SecuenciaRESUMEN
Thermal behavior of palm stearin (PS) and palm olein (PO) was explored by monitoring peak temperature transitions by differential scanning calorimetry (DSC). The fatty acid composition (FAC), isothermal crystallization kinetics studied by pulsed Nuclear Magnetic Resonance (pNMR) and isothermal microstructure were also compared. The results indicated that the fatty acid composition had an important influence on the crystallization process. PS and PO both exhibited more multiple endotherms than exotherms which showed irregular peak shapes. An increasing in cooling rate, generally, was associated with an increase in peak size. Application of the Avaimi equation to isothermal crystallization of PS and PO revealed different nucleation and growth mechanisms based on the Avrami exponents. PS quickly reached the end of crystallization because of more saturated triacylglycerol (TAG). The Avrami index of PS were the same as PO under the same isothermal condition at lower temperatrue, indicating that the crystallization mechanism of the two samples based on super-cooling state were the same. According to the polarized light microscope (PLM) images, crystal morphology of PS and PO was different. With the temperature increased, the structure of crystal network of both PS and PO gradually loosened.