Citric Acid Esters Research Articles

Preparation and characterization of rice starch citrates by superheated steam: A new strategy of producing resistant starch

In this study, starch citrates were synthesized by superheated steam (SS) treatment without changing the granule structure of starch. The degree of substitution (DS) of starch citrates prepared in present study was ranged from 0.015 to 0.064. Fourier transform infrared spectroscopy confirmed that citric acid (CA) and starch were successfully esterified with an absorption peak appeared at 1735 cm−1. In vitro digestion results revealed that the content of resistant starch (RS) was significantly increased by citric acid esterification, which was attributed to the cross-linked structure of starch and the inhibition of gelatinization and swelling. According to the physicochemical properties analysis, the pasting temperature of rice starch citrates were significantly increased by citric acid treatment, while the swelling power and gelatinization enthalpy were significantly decreased and the short- and long-range molecular order of the starch was disrupted after the esterification reaction. These results indicated that it is a feasible method to synthesize starch citrate by superheated steam to increase resistant starch, and it could be used as an alternative approach for preparing starch citrate to conventional hot air treatment.

Efficiency, functionality, and multi-scale structure of citric acid esterified glutinous rice starch synthesized via infrared radiation

To simplify the process, decrease output cost, and limit the amount of wastewater and gas generated in the production of esterified starch, highly citrate-substituted glutinous rice starch was prepared using infrared radiation (IR) technology. Physicochemical properties and multi-scale structure of different starch were characterized to assess effectiveness of IR in starch esterification. Absorption at 1749 cm-1 in the Fourier-transform infrared spectrum was determined in either IR-citric acid modification (ICM) or dry heat-citric acid modification (DCM), confirming occurrence of esterification. The use of IR shortened synthesis time (7 min) for ICM compared with DCM (5 h) to an equivalent degree of substitution of 0.154. Furthermore, while functional properties of ICM and DCM were not significantly different (p > 0.05), they featured better thermal stability, anti-retrogradation, and digestion resistance compared with native glutinous rice starch. IR and esterification treatment destroyed crystalline regions in glutinous rice starch and decreased the order of molecular chains. The loss of the crystalline region was consistent with the absence of endothermic peaks in IRM, ICM, and DCM as indicated by differential scanning calorimetry. The results suggest that the use of IR technology for citric acid esterification of glutinous rice starch is an effective alternative method for preparing high contents of thermally stable resistant starch, and provide insights regarding the potential industrial application of IR technology for diversifying starch modification methods.

Identifying Citric Acid Esters, a Class of Phthalate Substitute Plasticizers, in Indoor Dust via an Integrated Target, Suspect, and Characteristic Fragment-Dependent Screening Strategy.

Citrate acid esters (CAEs) have been proposed as a class of phthalate substitute plasticizers; however, information on their occurrence in indoor environments is rare. By using liquid chromatography coupled with a quadrupole-Orbitrap mass spectrometer, we developed an integrated strategy that can be applied for target, suspect, and characteristic fragment-dependent screening of CAEs. In n = 50 indoor dust samples collected from Nanjing City (China), three CAEs, namely, acetyl tributyl citrate (ATBC; mean: 412,000 ng/g), tributyl citrate (TBC, 11,600 ng/g), and triethyl citrate (TEC, 10,900 ng/g), exhibited the greatest contamination levels. Total concentrations of CAEs (∑8CAEs) were statistically significantly (p < 0.01) greater than those of common organophosphate triesters (OPTEs), a class of ubiquitous contaminants in dust. Suspect and characteristic fragment-dependent screening (m/z 111.0078 ([C5H3O3]+) and m/z 129.0181 ([C5H5O4]+)) of CAEs were further conducted for the same batch of samples. We tentatively identified six novel CAEs, and the most frequent and abundant CAE was fully identified as tributyl aconitate (TBA). Statistically significant correlation relationships were observed on dust levels between TBA vs ATBC (r = 0.650; p < 0.01) and TBA vs TBC (r = 0.384; p < 0.01), suggesting their similar sources in dust samples.

Effects on the structure and properties of native corn starch modified by enzymatic debranching (ED), microwave assisted esterification with citric acid (MCAE) and by the dual ED/MCAE treatment

Native corn starch was modified by enzymatic debranching (ED), microwave assisted citric acid esterification (MCAE), and by dual ED/MCAE. The structure and properties of native starch (NS), and the resulting debranched starch (DS), microwave assisted citric acid esterified starch (MCS), and microwave assisted citric acid debranched starch (MCDS) were determined and compared. Both the morphology and crystalline regions of the modified starches were changed by ED and MCAE. ED increased significantly the amylose content and transparency, but decreased the in vitro enzymatic digestibility, freeze thaw stability and relative crystallinity of DS compared to those of NS. MCAE produced a decrease in amylose content, transparency, in vitro enzymatic digestibility, and relative crystallinity, but increased the freeze-thaw stability of MCS compared to NS, and of MCDS compared to DS. The A-type crystalline structure of NS and DS was changed to B-type crystalline structure after MCAE treatment, and a new FTIR characteristic band at 1735 cm−1 was observed for MCS and MCDS. This work provides insights for producing esterified corn starches by a combined enzyme, microwave and organic acid novel technology.

Synthesis of &amp;lt;i&amp;gt;Capsicum chinense&amp;lt;/i&amp;gt; Citric Acid Esters-Its Methanol Trans-esterification Investigations with hplc Analysis and Its valorization as Gels-Crystals Ca-Salts

The esterification between citric acid molecules and raw material-<i>Capsicum chinense</i> organic molecules in excess was carried out at 137°C-410.15°K. The kinetics of the reaction showed that this reaction was second order compared with citric acid and the calculated initial and global speed constant were respectively 1.43×10^-1[L²×mol^-2×s^-1] and 3.84×10^-2 [L²×mol^-2×s^-1]. The synthesized raw material’s-<i>Capsicum chinense</i>’s citric acid esters solutions colors was from light yellow-1.5[mn] to highly orange yellow-60[mn] confirming the esterification between citric acid molecules and the main bioactive molecules constituting the Capsicum chinense including capsaïcine, quercetin and luteolin whose densities were superior to one and explained the high densities of the Capsicum chinense citric acid esters solutions between 0.9825[g/ml] to 1.0636[g/ml]. Then, the alkene concentrations in esters solutions recorded an increase initially and at the middle of the time reaction respectively due to citric acid dehydration and alkenes from the raw material’s-<i>Capsicum chinense</i>’s bioactive molecules. But, the diminution of these alkene concentrations recorded from 900[s] time reaction confirmed their etherification with carboxylic acid and/or alcohol organic functions catalyzed by citric acid’s protonic acid-H⁺. Second, the trans-esterification mechanisms of the raw materials’ citric acid esters solutions with methanol was explored, inventoried and carried out in order to extract its bioactive molecules and their derivatives synthesized during this trans-esterification reaction where citric acid’s protonic acid-H⁺ sites functioned as catalyst. Thus, a trans-esterification using reflux-assembly followed by an extraction procedures were established in this manuscript. Indeed, the hplc analysis of the dichloromethane extracts allowed to identify the <i>Capsicum chinense</i>’s bioactive molecules and these derivatives. Third, procedures to synthesize crystals and gel calcium salts of raw material’s citric acid esters solutions was established. An inventory of these gel-crystals structure was done in this manuscript and it was deduced that the first step of these procedures was the esters solution titration with NaOH-0.05N in order to determine the optimum quantities of calcium hydroxide for the synthesis using reflux assembly at 137°C followed by evaporations procedures. Then, once synthesized gel was suffered under thermic treatment until having solid crystals well-structured, both could be characterized by an established EDTA-0.01N and alkene procedures titrations established in this manuscript. Finally, an established titration procedure with NaOH-0.05N allowed to determine their equivalent citric acid molecules concentrations. It was noticed that their citric acid and calcium weight concentration ratio was respectively 4.354/1.67 (≈2/1) which confirmed the well-structured of the product regarding to the exploration salts synthesis-mechanisms figures done in this manuscript.

Synthesis of Glues with Citric Acid and Sulfuric Acid Protonic Acid-H&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; as Catalysts Using Banana Peel and Kaki as Valorised Raw Materials

Seeing that banana peel or banana skin composed 35% to 40% of banana fruit and also seeing that kaki were widely cultivated at Madagascar since the XIX^th century with non-negligible quantities of valorisable waste during their collection; a study of their valorization as raw materials to synthesize glues was undertaken in this manuscript. Synthesized glues were classified into two categories: the ecological glues with citric acid protonic acid H⁺ catalyst and the sulfuric acid glues-Sglues with sulfuric acid protonic acid H⁺ catalyst. All glues were composed with two main compounds firstly the pH-raiser-support and secondly the crushed banana peel citric acid esters EAcBa. These pH-raiser-supports was composed not only with citric acid protonic acid H⁺ catalyst (E-pH-Natural for the ecological glues) and/or sulfuric acid protonic acid H⁺ catalyst (E-pHS-sulfuric acid for the Sglues) but also pure ethanol and kaki composed with alkenes organic functional group from its betacarotenes molecules; they increased the pH of the glues and catalysts were dispersed and moved on. All synthesized glues were tested such as: the ecological glues were tested to glue the school notebook paper and the Sglues were tested to glue the packing carton paper. So, to study the effects of these gluing components, the effects of the test papers dry matter, the effects of tested papers nature-components, and the effects of the test papers porosities; the total weight diminution of the glue-reagents which indicated the formation of covalent links between glues and paper responsible of its best gluing results were followed with time. In terms, the activities of each glues’ initial protonic acid H⁺ were calculated and confirmed their roles as very active catalysts for dehydration reactions particularly the sulfuric acid protonic acid H⁺ catalysts, for addition reactions principally esterification, additions with alkenes-C⁼ and etherification for all synthesized glues especially with the stronger-smallest sulfuric acid protonic acid H⁺ which were responsible of their capacities to stick with very good quality.

The presence of crystalline sugar limits the influence of emulsifiers on cocoa butter crystallization

The effects of 2 wt% emulsifier and crystalline sugar on the isothermal solidification and polymorphic behavior of cocoa butter were evaluated. The emulsifiers investigated were commercial soy lecithin, polyglycerol polyricinoleate (PGPR), citric acid esters of mono- and diacylglycerols (CITREM) and ammonium phosphatides (AP). All emulsifiers accelerated cocoa butter nucleation and growth from the melt, with PGPR showing the smallest enhancement. Lecithin and AP minimally affected the polymorphic form IV-to-V transition contrary to PGPR and CITREM, whichboth promoted the formation of form V crystals. The presence of sugar alone accelerated cocoa butter solidification while limiting the ability of the emulsifiers to do so. Sugar alone, and in the presence of emulsifier, hindered the polymorphic form IV-to-V transition. This study shows that the effects of emulsifiers on the isothermal crystallization of cocoa butter can be muted in the presence of crystalline sugar, suggesting a complex interplay dependent on emulsifier molecular structure.

Analytical photo-centrifuge-based prediction of shelf-life and droplet packing behaviour of nanoemulsions upon removal of excess micelles

An analytical photo-centrifuge was used to develop novel experimental methods to predict the shelf-life, rheology, and inter-droplet interactions in 40 wt% canola oil-in-water nanoemulsions stabilized by 3 and 5 wt% citric acid esters of monoglyceride (Citrem). The combined influence of micellar concentration and oil droplet size on the rheology, creaming stability, and compression behaviour was studied under a series of accelerated gravitations. Nanoemulsions without excess Citrem micelles were obtained by removing them from the continuous phase using multiple cycles of ultracentrifugation. Reduction in droplet size with an increase in Citrem concentration and the removal of excess micelles resulted in a significant increase in plateau storage moduli leading to a change in phase behaviour of the nanoemulsions from liquid to viscoelastic gels. Moreover, it also showed a simultaneous drastic decrease in nanodroplets creaming velocity under accelerated gravitation. The flow behaviour of the gels was well correlated with a critical relative centrifugal force required to initiate flow under accelerated gravitation. Additionally, the colloidal forces responsible for instability was satisfactorily explained by the packing behaviour of the nanodroplets studied under a series of compression and dilatational cycles of centrifugation. We showed that the strong electrostatic repulsive force between the nanodroplets without excess micelles led to a lower packing density during compaction that did not change significantly during successive dilatational cycles. The higher packing density or compaction in the presence of excess micelles was explained by the short-range attractive depletion forces leading to weak flocculation of nanodroplets. Overall, the presence and absence of excess micelles showed a significant influence on the rheology and accelerated stability of nanoemulsions, which can be further described by the colloidal forces between the nanodroplets using the real-time advanced photo-centrifuge.

Synthesis of a reactive boron-based flame retardant to enhance the flame retardancy of silk

In this study, a reactive boron-containing flame retardant (FR) namely glycerol borate citric acid ester (GBCAE) was synthesized using boric acid, glycerol and citric acid, and was applied to improve the flame retardancy of silk fabric. The chemical structure of GBCAE and its potential cross-linking reactions with silk fiber were characterized. The thermal stability, smoke and heat suppression capacity and FR ability of the treated silk were evaluated. The treated silk fabrics with a weight gain of higher than 7.3% had self-extinguishing ability. The FR treatment endowed high thermal stability and excellent flame retardancy to silk, and suppressed the smoke and heat release of silk by nearly 50%. The treated silk could still self-extinguish after 5 washing cycles and showed good washing durability, which is attributed to the covalent cross-linking action between GBCAE and silk fiber. The char residue analyses on morphology and functional groups indicated the intumescent FR mechanism for the treated silk. The prepared GBCAE has great potential to serve as suitable alternative to toxic halogen-based agents for improving the flame retardancy of silk textiles

Characterization of E 472 food emulsifiers – determination of bound and free fruit acids, free glycerol and ash content

Emulsifiers of the type E 472 are esters of fruit acids and mono- and diacylglycerols (MAG and DAG), which are used to adjust techno-functional properties in various food products. The most dominant representatives of E 472 emulsifiers are acetic acid esters (E 472a), lactic acid esters (E 472b), citric acid esters (E 472c), and mono- and diacetyl tartaric acid esters (E 472e). For the determination of fruit acids, a high-performance liquid chromatography method with ultraviolet light (HPLC–UV) detection was developed. Free and total fruit acids were determined by reversed phase HPLC–UV analysis of untreated and saponified emulsifier extracts with 20 mM potassium hydrogen phosphate buffer (pH 2.6) as isocratic eluent. Limits of quantitation of 0.08–0.27 g free fruit acid/kg emulsifier and 4–14 g total fruit acid/kg granted a reliable method with recoveries for free and total fruit acids between 80 and 100% with relative standard deviations (%RSD) below 4%. For the quantitation of free glycerol by spectrophotometry, an enzymatic assay was optimized for the analysis of E 472 providing reliable results with %RSD values below 9%. In addition, the ash content of E 472 emulsifiers was determined.

The Effect of Cross-Linking with Citric Acid on the Properties of Agar/Fish Gelatin Films.

The aim of this work was to assess the effect of fish gelatin–citric acid nucleophilic substitution and agar–citric acid esterification reactions on the properties of agar/fish gelatin films. Since temperature is an important cross-linking parameter, films were treated at 90 °C and 105 °C and film properties were compared to those of non-cured films. It was observed that temperature favored the aforementioned reactions, which induced physical and morphological changes. In this regard, darker films with a rougher surface were obtained for the films with a higher cross-linking degree. While mechanical properties were slightly modified, the barrier properties were enhanced due to the reactions that occurred. Therefore, these agar/fish gelatin films cross-linked through two different reactions can be considered to be promising materials as active films for different purposes, such as active packaging or pharmaceutical applications.

Characterization of E 472 food emulsifiers by high-performance thin-layer chromatography with fluorescence detection and mass spectrometry

Esters of fruit acids including acetic acid and mono- and diacylglycerols (MAG and DAG), also known as E 472 emulsifiers, are used in the food industry as food additives to adjust techno-functional properties like viscosity, emulsion stability and foaming stability in various products, mainly dairy products. Based on the respective acids, E 472 emulsifiers are classified in several categories with acetic acid esters (ACETEM, E 472a), lactic acid esters (LACTEM, E 472b), citric acid esters (CITREM, E 472c), and mono- and diacetyl tartaric acid esters (DATEM, E 472e) as the most prominent representatives. Besides fruit acid esters, E 472 emulsifiers mainly comprise MAG, DAG, triacylglycerols, free fatty acids, free fruit acids and free glycerol in different amounts. Here we present an innovative and sensitive method for the characterization of the composition of E 472 emulsifiers by high-performance thin-layer chromatography with fluorescence detection (HPTLC–FLD). For HPTLC–FLD, technical emulsifiers were simply dissolved and analyzed on HPTLC silica gel plates after a two-fold development and derivatization with primuline, enabling the easy characterization and direct visual comparison of the emulsifier pattern (fingerprint) through the fluorescent lipid components under UV 366 nm. Thus, the HPTLC–FLD fingerprint approach represents a simple tool for the comparison of different samples, batches and categories of E 472. Coupling of HPTLC to mass spectrometry moreover enabled the identification of constituents of interest.

Conversion of Viscous Oil-in-Water Nanoemulsions to Viscoelastic Gels upon Removal of Excess Ionic Emulsifier.

Viscous, flowable nanoemulsions stabilized with ionic emulsifier can be transformed into repulsively jammed elastic gels that do not flow under gravity by reducing the droplet size and increasing the interfacial repulsive shell layer thickness. However, a high concentration of emulsifier required to achieve nanodroplets could remain in the continuous phase and lead to oscillatory structural forces, thereby reducing repulsive interaction and forming flowable liquid systems. It was hypothesized that the removal of excess emulsifier from a nanoemulsion could lead to the formation of repulsive gels. Canola oil-in-water nanoemulsions, containing 40 wt % oil, were prepared with a citric acid ester of monoglyceride (Citrem) using a high-pressure homogenizer. The excess emulsifier in the aqueous phase was removed by multiple ultracentrifugation cycles, and the droplet size, rheology, and stability of the nanoemulsions were investigated as a function of excess Citrem concentration. Nanoemulsions with average droplet sizes of 222 and 150 nm were obtained with 3 and 5 wt % Citrem, respectively. The removal of excess Citrem did not change the droplet size significantly. However, the viscosity, yield stress, and storage moduli increased significantly with the reduction of excess Citrem and the decrease in droplet size, converting the flowable weak gel nanoemulsion to a strong viscoelastic gel. The calculated values of oscillatory structural forces decreased with the removal of excess emulsifier, leading to an increase in repulsive interactions and the thickness of the electric double layer. Such an increase in interdroplet separation led to an increase in the effective oil volume fraction beyond the maximum random jamming of oil droplets and the formation of a viscoelastic nanoemulsion gel.

IDENTIFICATION AND QUANTITATIVE DETERMINATION OF ESTERS OF CITRIC ACID

The necessity and possibility of creating a domestic technology for the production of citric acid esters - trialkyl citrates - effective and environmentally friendly plasticizing compositions based on renewable raw materials are substantiated. Trialkylcitrates a purity of 98-99% are obtained by azeotropic esterification of citric acid with aliphatic alcohols C4-C5 under conditions of homogeneous acid catalysis. Using the synthesis of triamyl citrate as an example, the esterification of a polybasic hydroxy acid has been considered. It was established that during the synthesis a complex mixture is formed consisting of unreacted citric acid, incomplete mono-, diesters and triamyl citrate. The influence of synthesis conditions (temperature, reagent ratio, catalyst amount and reaction time) on the composition of the reaction mass is shown. A method of gas chromatographic analysis of citric acid esters has been developed. Taking into account the structural features of citric acid and its partial esters containing polar carboxyl groups, the reaction mass was pre-methylated with synthesized diazomethane. The resulting mixture consists of six esters of citric acid: trimethylcitrate; 2-hydroxy-1,3-dicarboxymethyl-2-carboxyamylpropane; 2-hydroxy-1,2-dicarboxymethyl-3-carboxyamil propane; 2-hydroxy-1-carboxymethyl-2,3-dicarboxysamyl propane; 2-hydroxy-2-carboxymethyl-1,3-dicarboxyamyl propane; triamylcitrate. The analysis was performed on a chromatographic complex "Crystal-2000M" on a capillary column with a grafted non-polar phase OV-101, length 100 m. The analysis time ranged from 22 to 49.5 min. Empirical equations were obtained using the internal standard method (the standard is dicyclohexyl adipate) to determine the calibration coefficients of the starting (trimethyl citrate т citric acid) and final (triamyl citrate) products in a wide concentration range. The results of identification of structures of six esters of citric acid for which there is no information in existing databases are presented. The study was carried out by method of chromato-mass spectrometry on the instrument SHIMADZU GCMS – QP2010 with ionization by electron impact at ionization energy of 130 eV. The analysis of the obtained spectra made it possible to determine the most probable ways of fragmentation of organic molecules and the intensity of the peaks of the ions formed.

A comparison of the physico‐mechanical properties of two proprietary PLA based resorbable graft materials

Background A wide range of auto-, allo- and xenograft materials are used in reconstructive implant related therapy. Such materials used as barrier membranes confer a number of properties related to their manufacturing and processing. Resorbable synthetic polymers+ PLA, PGA's and Caprolactone are widely used polymers in medical devices and an understanding of the physico- mechanical properties including TGA, DSC, TMA, and PGC will assist in the selection of optimal properties. Aim/Hypothesis The aims of this study were to compare the physico-mechanical behaviour of two polymer based resorbable graft materials+ Guidor and Polyoss to better understand how their properties can be correlated to their clinical behaviour. Materials and Methods Samples of two proprietary PLA based membrane materials were selected for study; Guidor (Sunstar Chemicals; Germany) and Polyoss R (Ossform pty; Australia). The material samples were subjected to DSC, TGA, TMA and GPC to gain an understanding of their properties. Ossform is synthesised as a filament for 3D printing so samples of raw material, filament and printed material, pre and post-gamma irradiation were investigated to study the effects of any of material processing. Gel Permeation Chromatography (GPC)was performed using an Agilent Technologies 1260 with (THF). The peaks were detected using a refractive index detector (40 ⁰C). Thermo-Gravimetric Analysis (TGA)was performed using a TA SDT650. A 3 to 7 mg polymer sample was used for measurements. The sample was heated to 600 C at 10 ⁰C/min under a flow of nitrogen (50 ml/min). The Td was calculated at 5% weight loss. Differential Scanning Calorimetry (DSC) was performed using a TA DSC250. Tg, Tc, Tm, and ∆Hm were identified. Results Guidor is a PLA based material manufactured as a barrier membrane for periodontal and implant reconstruction. TGA demonstrated a second peak in the plot at 30°C for Guidor as compared with Polyoss. This indicated approximately 15% of citric acid esters in the sample. Guidor had a low molecular weight of 54-56000 and an Mn of 88-90000. The degradation temperature was also low at 227-231°C. There was little difference in properties between the first and second TGA scan. Polyoss-R is a medical grade PLA based polymer designed for the production of grafts, membranes and shells by 3D printing. Four samples were analysed granular (PG), filament (PF), gamma sterilised filament (PFG) and printed sample (PS). Polyoss – R is a higher molecular weight polymer with a mwt of 159-285000 and Mn 111-196000. It had a PD of 1.4-1.5 and a midpoint degradation temperature of 262–316°C. The difference in the DSC for PG in the first and second run can be attributable to a reorganisation of the polymer. Conclusion and Clinical Implications Synthetic polymers offer significant benefits in the development of stable and three-dimensional grafts and barrier membranes. Guidor is a well established material and its measured properties correlate well its clinical performance. Its low molecular weight will give it a fairly short resorption time (6–8 weeks). Whilst that for Polyoss-R will be longer (c.12 weeks). This investigation the production processes can produce successful bioresorbable polymers suitable for clinical use.

Synthesis and characterization of citric acid esterified rice starch by reactive extrusion: A new method of producing resistant starch

Citric acid-esterified rice starch was synthesized using a one-step reactive extrusion method. The structure, physicochemical properties, and digestibility of the esterified starch were then measured. An in vitro digestion study indicated that esterification significantly increased the level of resistant starch (RS) in the samples. Fourier transform infrared spectroscopy (FT-IR) confirmed esterification had occurred between the citric acid and starch, with a new peak appearing at around 1730 cm−1. X-ray diffraction indicated that esterification caused a decrease in the degree of crystallinity in the starch. The swelling power and solubility of starch citrate were both lower than unmodified starch. Turbidity measurements suggested there was a slower rate of reassociation in starch citrates during storage. These results suggest that citric acid esterification promoted cross-linking within the starch that significantly reduced its digestibility. This simple method may be useful for the creation of healthier starchy foods.

Plasticizers Derived from Biomass Resources: A Short Review.

With rising environmental concerns and depletion of petrochemical resources, biomass-based chemicals have been paid more attention. Polyvinyl chloride (PVC) plasticizers derived from biomass resources (vegetable oil, cardanol, vegetable fatty acid, glycerol and citric acid) have been widely studied to replace petroleum-based o-phthalate plasticizers. These bio-based plasticizers mainly include epoxidized plasticizer, polyester plasticizer, macromolecular plasticizer, flame retardant plasticizer, citric acid ester plasticizer, glyceryl ester plasticizer and internal plasticizer. Bio-based plasticizers with the advantages of renewability, degradability, hypotoxicity, excellent solvent resistant extraction and plasticizing performances make them potential to replace o-phthalate plasticizers partially or totally. In this review, we classify different types of bio-based plasticizers according to their chemical structure and function, and highlight recent advances in multifunctional applications of bio-based plasticizers in PVC products. This study will increase the interest of researchers in bio-based plasticizers and the development of new ideas in this field.

Effects of heat-moisture treatment after citric acid esterification on structural properties and digestibility of wheat starch, A- and B-type starch granules

In this study, wheat starch, A- and B-type starch granules were firstly treated with citric acid (CT) and then subjected to heat-moisture treatment (HMT). The maximum thermo-stable resistant starch (RS) contents reached 71.52%, 71.27%, 71.58% for CT-HMT wheat starch, A- and B-type starch granules, respectively. The hydrolysis kinetic parameters (C∞ and k) reduced after CT-HMT. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results revealed that the endothermic and crystalline peaks of CT-HMT starch samples disappeared. Scanning electron microscopy (SEM) results showed that more collapses and destructiveness appeared on the surfaces of CT-HMT starch granules. The esterification reaction became stronger during HMT according to Fourier transform-infrared (FT-IR) spectroscopy analysis, which was consistent with the results of degree of substitution. Raman spectroscopy presented similar structural properties results with XRD and FT-IR. These results suggest that CT prior to HMT is a useful method for preparing high amount of thermally stable RS.

Effect of banana powder and butter on the formation of the crystalline phase of sugar fondant

Taking into consideration modern requirements to technological characteristics of decorative semi-finished products, micronutrient composition, we developed the formulation for the innovative confectionery semi-finished product, which is based on sugar fondant with addition of the mixture of butter, banana powder and the surface-active substance (citric acid ester, mono-diglycerides – SAS). It is universal and is designed for the production of a wide range of decorative semi-finished products (creams, fillings, icing, etc.).We conducted the study of the influence of the mixture of butter, banana powder and surfactant on thermo-physical properties and the structure of the confectionery semi-finished product for confectionery decoration.The aim of this research was to study the influence of the selected ingredients on the process of formation of the crystal phase of sugar fondant, which is the basis for the confectionery semi-finished product.Results of the study revealed that during the formation of the crystal phase of the semi-finished product, the existence of the banana powder components leads to differentiation of carbohydrates of sugar fondant by melting temperature. This suggests that recrystallization processes flow less intensively compared to the control sample during the storage of the enriched fondant cream.The addition of SAS helps obtain a homogeneous polyphase system, which is proved by the homogeneous elastic structure. Micro-structural research showed that fondant crystals and vegetable powder particles are surrounded by fat phase of butter and swollen powder particles do not form groups.Results of the micro-structural analysis and of the differential scanning calorimetry made it possible to propose the mechanism of interaction of banana powder particles with fat phase and the oversaturated solution of sucrose.The obtained results explain aggregation stability and thermal stability of the universal confectionery semi-finished product at multiple thermal and mechanical influence, which is of technological importance.

Effects of Heating Temperatures and Acid Concentrations on Physicochemical Properties and Starch Digestibility of Citric Acid Esterified Tapioca Starches

Physicochemical properties and starch digestibility of modified tapioca starch using various citric acid concentrations (10, 30, and 50 g/100 g dry starch) and heating temperatures (100, 120, and 140 °C for 5 h) are investigated. It is found that the degree of esterification increases with increasing dose of citric acid and heating temperature. Differential scanning calorimetry shows that citrate starch samples exposed to high acid dose (30 g/100 g citric acid) and temperature (120 °C) are resistant to gelatinization. In addition, transitional enthalpy also decreases with increasing concentration and temperature. The microstructure of esterified starch is observed to have agglomerated granules, with corrosions/fissures and small overlapping layers on the surfaces, which are observed in all modified samples. Citric acid esterification of tapioca starch provided advantages in terms of the increase resistant starch content and slow digestion rate when compared to native starch.