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关键词： Chemical transesterification   medium- and long-chain triacylglycerols   diacylglycerol   oxidative stability   minor compounds  

摘要： A type of medium- and long-chain triacylglycerols (MLCT) rich in alpha-linolenic acid (ALA) was produced by chemical transesterification of medium-chain triacylglycerols (MCT) and flaxseed oils. Under the optimal substrate conditions of 60%, catalyst loading of 0.3% at 60 degrees C for 15 min, the product contained MLCT (74.06%), ALA (37.26%) and diacylglycerol (DAG) (11.25%). After that, changes in fatty acid (FA) composition, physicochemical properties and minor compounds after chemical transesterification (CTE) were investigated. The correlations analysis results of these factors on oxidative stability showed these factors could be divided into positive and negative groups. Although DAG appears to be beneficial in slowing down oil oxidation, it is critical to avoid its mass production because it would decrease MLCT.

关键词： [NH3(CH2)(4)(NH3)]ZnBr4   Perovskite type   Nuclear magnetic resonance   Organic-inorganic hybrid  

摘要： Despite having a wide range of applications as an organic-inorganic hybrid perovskite, detailed studies of the physical properties and structural dynamics of [NH3(CH2)(4)NH3]ZnBr4 crystals have not been published to date. This work investigates the structural properties of these crystals using X-ray diffraction, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The crystal structure was orthorhombic, and the phase-transition temperatures were 354, 434, and 514 K. In addition, the physicochemical properties of the cations in this crystal were investigated using H-1 and C-13 nuclear magnetic resonance (NMR) relaxation. The structural environments of H-1 and C-13 as evaluated by chemical shifts in the [NH3(CH2)(4)(NH3)] cation did not change significantly with increasing temperature. The spin-lattice relaxation times T-1 rho for H-1 were dependent on temperature change, but the T-1 rho for C-13 located in the center of the N-C-C-C-C-N bond was nearly independent of temperature. We compared [NH3(CH2)(3)NH3]ZnBr4 crystals previously reported and the [NH3(CH2)(4)(NH3)]ZnBr4 crystals prepared herein.

关键词： Chlorella vulgaris   Arthrospira platensis   Dunaliella salina extract   Rheology   Jams   Microalgae  

摘要： Jams are preparations of fruits whose main preserving agent is sugar. Due to this, health concerns of consumers have resulted in a sugar reduction, and its replacement using alternative sweeteners and introducing new ingredients enhancing nutritional properties. In this study, four types of fruits jams (plum, strawberry, apple, and peach), with or without sugar, were prepared using two microalgae biomass, Arthrospira platensis (Spirulina) and Chlorella vulgaris, and Dunaliella salina extract as ingredients at different mix levels of concentrations, 0.10%-0.10%-0.05% respectively, for plum;0.04%-0.00%-0.01 respectively, for strawberry;0.06%-0.04%-0.00% respectively, for apple and 0.00%-0.01%-0.04% respectively, for peach. Physicochemical, rheological, and textural parameters were evaluated. Substitution of sugar/fructose syrup in the jam's preparation caused changes in pH values, solid soluble content, and rheological and textural properties compared to sugar jams. Using sugar or sweeteners as isomalt, stevia and sucralose and microalgae biomass or extract showed significant changes in colour coordinates, however, these differences were not perceptible by the human eye. Jams containing microalgae biomass-extract showed higher G', G'', G*, and eta* values than their corresponding control samples. All the jams presented weak-gel characteristics, distinguishing fruit jams. However, the results of weak-gel model analysis suggest that the influence of the different ingredients in the food system depends not only on their concentration but also on the interactions in the gel structure. Strawberry and apple jams showed no significant differences between microalgae biomass-extract samples and control samples, for both sugar and no sugar added jams being the best-obtained samples.

关键词： Biofuels   Biomass   Oil palm biomass   Physicochemical properties of biomass   Pyrolysis  

摘要： The objective of this work is to evaluate the potential of oil palm biomass (OPB) in terms of physicochemical properties for producing biofuels via pyrolysis processes. The OPB included oil palm trunk (OPT), oil palm fronds (OPF), oil palm shell (OPS), oil palm roots (OPR), oil palm decanter cake (OPDC), empty fruit bunches (EFB), oil palm fiber (OPFB), and oil palm sewage sludge (OPSS). Their physicochemical properties are considered on several physical, chemical, and thermal aspects. The results showed that particle size distribution and bulk density of ground OPB were different. The proximate analysis results of OPB were consistent with the lignocellulose content and extractives. The carbon and hydrogen content of the OPB were also correlated with the organic components. Some OPB contained high lignin and extractives. The lignin content of OPB strongly influenced to thermal decomposition trend. OPB contained high inorganic elements such as potassium (K), calcium (C), and iron (Fe). The higher heating value and potential use as energy equivalent with fossil fuels of the OPB were relatively low. OPB had low thermal conductivity, and the dielectric constant, loss factor, and tangent loss of the OPB were also low. Thus, these results will be beneficial for the researchers and biofuel producers for choosing the appropriate OPB, as well as the operating conditions and reactor types.

关键词： Extra-large-pore   Silicoaluminophosphate   Ionothermal synthesis   Methanol-to-olefin   Propene oligomerization  

摘要： Silicoaluminophosphate zeotypes with -CLO structure (SAPO-CLO) were ionothermally synthesized in 1-ethyl-3-methyl imidazolium ([emim](+)) ionic liquid in the presence of tetrapropylammonium hydroxide. The physicochemical properties of SAPO-CLO with different silicon content were comparatively studied using several characterization techniques including XRD, SEM, XRF, NMR, BET, NH3-TPD, in situ DRIFTS etc. Notably, Si-29 MAS NMR results revealed the incorporation of Si in the structure that was mainly in the form of SMII and SMIII combination. NH3-TPD and in situ DRIFTS results demonstrated that SAPO-CLO exhibited higher acid amount than AlPO-CLO as a result of the formation of new Bronsted acid sites Si-OH-Al in addition to structural P-OH in the framework. N-2 physisorption results showed SAPO-CLO compared with AlPO-CLO exhibited higher BET surface area and microporous volume with the presence of extra-large-pore of about 1.2 nm. Finally, the catalytic performance of SAPO-CLO was evaluated in both methanol-to-olefin and propene oligomerization reactions to elucidate its activity, shape-selectivity and hydrothermal stability. SAPO-CLO showed improved catalytic activity in comparison to AlPO-CLO in both reactions, and lower selectivity of light olefins in the former reaction and higher selectivity of C-3n oligomers in the latter reaction in comparison to small-pore SAPO-LTA. The deactivated catalyst was unrecoverable in MTO reaction due to structure degradation by water produced during the reaction, whereas recoverable in oligomerization reaction after the removal of coke by high temperature calcination.

关键词： Shelf-life   Polygalacturonase   Apparent dynamic viscosity   Phenolic profile   Antioxidant capacity  

摘要： The influence of static and multi-pulsed high pressure processing (HPP) on the quality of raw apple juice during refrigerated storage (4 degrees C for 12 weeks) was evaluated. Processing at 300 MPa (three pulses;for 5 min each;15 min in total), 450 and 600 MPa (a single pulse for 5 min) caused a greater reduction in microorganisms than a single pulse at 300 MPa for 5 min. No significant changes were observed in polygalacturonase (PG) activity. HPP treatment and storage time significantly increased apparent dynamic viscosity and turbidity, while a decrease was noted in the concentration of vitamin C. Quercetin, gallic acid, procyanidin B2 and catechin were totally degraded after the 4th week. The antioxidant activity was strongly correlated with the total polyphenolic content (TPC) and individual polyphenols. During the 12 months of storage, each juice treated by HPP turned out to be darker as evidenced by a decrease in L* value and increasing the browning index (BI). A comparable microbial quality during 12 weeks of storage was achieved for juice treated with 300 MPa x 3 and with 600 MPa, which indicates that multi-pulsed HPP can be good alternative for juice preservation resulting in the increased of equipment working life.

关键词： Bakery shortening   Rice cookie   Physicochemical properties   Texture   Storage  

摘要： The aim of this study was to investigate the physicochemical and sensory properties of rice cookies prepared from zero trans shortenings. The shortenings were prepared from Ardeh oil and Palm stearin blends a ratios of 50:50 and 60:40 (%weight) by chemical interestification and then the cookies were made from them compared with a sample prepared from the commercial shortening (c-sh) available on the market. The fatty acids profile, slip melting point, solid fat content and chemical properties (peroxide value and free fatty acids) were determined in shortenings. The textural (hardness, adhesiveness) and rheological characteristics of shortenings were determined using texture analyzer and rheometer, respectively. Ardeh oil due to its high unsaturated fatty acid content [oleic (39.48%) and linoleic acids (42.31%)], and natural antioxidants such as Tocopherols (507 mg/kg) as well as good aroma and taste improved the physicochemical and functional properties of shortenings. Textural characteristics (hardness, fracturability) during storage and sensory attributes (texture, flavor and overall sensorial acceptance) as well as chemical properties (peroxide value, pH) of cookies prepared from zero-trans blends (0.2-0.3% trans acids) were better than those of a commercial shortening (4.74%trans fatty acids). Thus, it can be concluded that the produced shortenings used in rice cookies improved the product quality, also due to low levels of saturated fatty acids and zero trans fats, thus it has a potential to improve well-being.

关键词： Dipteryx alata Vogel   hydrocolloid   Musa acuminata 'Dwarf Cavendish'   non-conventional starch   plant-based food   thermal properties  

摘要： This study aimed to isolate and characterise green banana starch (GBS) and to investigate the effect of adding 0%, 1.5%, 3.0%, 4.5% and 6.0% GBS on physicochemical and sensory properties of a fermented product based on baru almond (Dipteryx alata Vogel) water extract with probiotic bacteria. GBS showed high gelatinisation temperature (73.37 oC), enthalpy (16.61 J g(-1)) and final viscosity (239.6 RVU). On the contrary, it showed a low tendency to retrograde (67.53 RVU), water solubility (0.02%), water absorption (1.85 g g(-1)) and gel hardness (6.7 N). Higher addition levels of GBS increased firmness, reduced syneresis and positively affected pH, titratable acid, soluble solids and colour of baru almond-based fermented products. The incorporation of 4.5% GBS was well accepted and preferred over the control sample (no GBS addition). GBS can be used as a natural thickener. The baru almond-based fermented product with 4.5% GBS stands out for having potential probiotic properties and for being a promising dairy alternative.

关键词： Nano eggshell calcium   Myosin   Microstructure   Gel properties   Synergistic mechanism  

摘要： In order to explore the mechanism of nano eggshell calcium (NEC) enhancing the gel properties of surimi. The effects of NEC on the structure, physicochemical, and gel properties of myosin were investigated. The results revealed that the addition of NEC improved gel strength, storage modulus G', and surface hydrophobicity of myosin. The maximum value was reached when the addition was 1.0 g/100 g. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the addition of NEC has a significant effect on the cross-linking of myosin heavy chain (MHC). FT-IR and fluorescence spectroscopy analysis indicated that NEC could induce the unfolding of myosin and promoted the conformational transition from alpha-helix to beta-sheet. Scanning electron microscopy (SEM) observed that adding a moderate content of NEC (<= 1.0 g/100 g) was conducive to the formation of homogeneous and dense three-dimensional network structure of myosin mixed gel. However, the addition of excessive NEC (>= 1.25 g/100 g) weakened its structural properties. These results of the present study suggested that NEC has potential to be applied in surimi seafood products, and has potential applications in improving the gel structure and gel properties.

关键词： Wastewater   Corn-lime-cooking-liquor   Arabinoxylans   Ferulic acid   Drying methods   Rheological properties  

摘要： Corn-lime-cooking-liquor (nejayote), which is a pollutant wastewater from the corn-tortilla-industry, contains valuable products, such as arabinoxylans (AXs) and phenolics. Recently, an innovative process that employs enzymatic and ultrafiltration processes for recovering and purifying AXs from nejayote was described, although neither the drying methods nor the physicochemical and rheological properties of the recovered AXs by this method at the pilot plant scale have been studied. Nejayote from a batch artisanal process (NBAP) and from a continuous industrial process (NCIP) were compared with a corn-bran-hydrolysate (CBH) as sources for AXs obtention. Freeze drying (FD), spray drying (SD) and solvent drying (SoD) were assessed as processes for drying purified and concentrated AXs solutions. Regardless of the process, AXs obtained from nejayote contain 3 times less (0.30 mg/g) esterified ferulic acid (EFA) than did AXs from corn bran (1.01 mg/g) and thus fail to yield elastic gels upon oxidative cross-linking. Molecular weight distribution (MwD) and dynamic viscosity data show that AXs from nejayote are shorter than AXs from corn bran. In general, the drying method had no effect on the physicochemical and rheological properties of AXs, although additional purification using ethanol precipitation and SoD, eliminated low molecular weight oligosaccharides and residual salts resulting from the neutralization of the corn-lime-cooking-liquor. Spray drying seems to be the most cost-effective unit operation for the industrial production of AXs from nejayote without affecting their physicochemical characteristics.