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The conversion of sesamin to asarinin is a promising route for the production of asarinin. This work reports the affection of acid type and strength of the catalyst on the conversion of sesamin to asarinin and the effect of various reaction conditions in anhydrous ethanol using phosphotungstic acid (HPW) as catalyst. The experimental results indicate that the activity of sesamin conversion is determined by strong B acids. L acids are not active for the reaction, and do not show synergy with B acids for the formation of asarinin. Reaction time, HPW dosage and temperature have significant effects on sesamin conversion. A maximum asarinin yield of 57.93% was achieved. The reaction kinetics in the temperature range 55-75 °C were studied. The kinetic curves can be successfully fitted with an opposing first-order reaction model. The activation energy (Ea) for this reaction is found to be 105.2 ± 0.4 kJ/mol.

The objective of the present investigation was to extract pectic polysaccharides from sesame seed hull and to determine their physicochemical and functional characteristics. The pectic polysaccharides in the seed hull were extracted with HCl and then collected at three ethanol concentrations of 30% (SSP30), 50% (SSP50), and 90% (SSP90). We found that SSP30 represented 75.6% of the total polysaccharides, and that it contained 76.39% galacturonic acid, with many HG domains and few short side chains in the RG-I domains. SSP30 exhibited the strongest hydroxyl radical scavenging activity among the three fractions, and was better able to stabilize the emulsions. Higher Mw pectic polysaccharides were firstly precipitated at lower ethanol concentrations, and the Mw of the precipitated pectic polysaccharides decreased with increasing ethanol concentration. These results provide important information on the structure and functional characteristics of sesame hull polysaccharides. This information can contribute to the future development of sesame hull polysaccharides for industrial purposes.

Chinese quince (Chaenomeles sinensis) fruits offer a potential source of pectin and hemicellulose. However, the existence of lignin-carbohydrate complexes (LCCs) can negatively impact the extraction of pectin and hemicellulose. In this work, LCCs were sequentially fractionated from Chinese quince during the removal of pectin and hemicellulose. The structures of LCCs were characterized by HPAEC, FT-IR, GPC, Py-GC/MS, TGA and 2D HSQC NMR. The results showed that the carbohydrate content and molecular weight of LCCs was found to be changed significantly after the removal of hemicellulose (KSH). The lignin in Björkman LCCs was found to be linked mainly to galactan and fructan, whereas the lignin LCC-AcOHs was found to be linked mainly to arabinan after the removal of KSH. The isolation of carbonate-soluble pectin (NSP) increased thermal stability of Björkman LCC fraction, however, the isolation of chelator-soluble pectin (CSP) increased the thermal stability of LCC-AcOHs. The S/G ratios of LCC-AcOHs increased and large amounts of S-type lignin released during sequential fractionation of pectin and hemicellulose. These results will be beneficial for understanding the mechanisms of pectin and hemicellulose isolation, thereby facilitating the potential application of Chinese quince as a valuable natural resource for food and other industries.

The main objective of the present investigation was to evaluate the potential of using the seed gum of Chinese quince (CQSG) as a wall material for flaxseed oil microencapsulation via freeze-drying...

Chinese quince is one kind of crop that has edibility and historical medical applications. However, the high amount of lignin makes processing Chinese quince fruit difficult; on the other hand, this lignin represents a valuable resource if a way of using it in industrial applications could be found. In this study, the structural features and antioxidant activities of Brauns native lignin (BNL) isolated from Chinese quince fruit after oven drying (60 °C, 75 °C, and 90 °C), sun drying, freeze-drying, and subcritical dimethyl ether drying were assessed. The BNL samples had low molecular weights (Mw, 2604–5511 g/mol), high carbohydrate content (6.10–9.95 %), and high phenolic OH content (1.76–2.29 mmol/g). NMR spectra showed that the BNL is of the SGH-type with the relative content of p-hydroxyphenyl units ranging from 13 to 21 %. Oven drying (90 °C) reduced the carbohydrate content and increased the phenolic hydroxyl content. Freeze-drying reduced the relative content of β-O-4′ linkages and increased the H-unit content. In terms of antioxidant activities, all samples possessed high DPPH free radical scavenging capacity (IC50, 0.12−0.22 mg/mL) and strong reducing power. These results indicate that BNL extracted from Chinese quince fruit is a promising source of natural antioxidant and biomass material.

In the present work, effects of reaction temperature, reactant concentration, catalyst loading, and rotation speed on the kinetics of sesamin conversion in a sesame oil system were studied by using citric acid loading on Hβ zeolite (CA/Hβ) as a catalyst. A kinetic model was built for sesamin conversion. The kinetic model fits correctly the experimental concentration of sesamin and asarinin (RS⁢e⁢s⁢a⁢m⁢i⁢n2 = 0.93 and RA⁢s⁢a⁢r⁢i⁢n⁢i⁢n2 = 0.97). The sesamin conversion is an endothermic reaction (△HrIso = 3 4.578kJ/mol). The CA/Hβ catalyst could be easily regenerated by calcination, and there was no obvious loss of catalytic activity when reused. Knowledge of the sesamin conversion is of great significance for guiding production and improving the value and nutrition of sesame oil. In a word, this study lays the foundation for the scale-up of the production of asarinin from sesame oil using CA/Hβ as the catalyst.

Sesame seed hull is the major by-product of sesame seed processing and is rich in polysaccharides. In this work, sesame hull polysaccharides (SHP) were extracted by ultrasound-assisted alkali extraction methods with a yield of 6.49%. Three purified polysaccharide fractions were obtained after decolorization, deproteinization, and column chromatography. Then, their main composition and antioxidant activity were investigated. The dominant fraction was SHP-2 with a yield of 3.78%. It was composed of galacturonic acid (51.3%), glucuronic acid (13.8%), rhamnose (8.9%), glucose (8.4%), and others. The linkage types of SHP-2 have the α-D-GalpA-(1,4)-linked, α-D-GlcpA-(1,2)-linked, β-T-D-Rhap-linked, β-D-Glcp-(1,6)-linked, β-T-D-Galp-linked, α-L-Xylp-(1,4)-linked, α-L-Araf-(1,3,5)-linked, and β-D-Manp-(1,4)-linked. This study might provide some useful basic data for developing applications for sesame seed hull polysaccharides in the food and pharmaceutical industries.

This article reports a study of the degradation of roasted sesame hulls cellulosic polysaccharides contribution to the Maillard and caramelization reaction. In the present study, cellulosic polysaccharides were extracted from sesame hulls before and after roasting at various temperatures (160, 180, 200, and 220 °C). The structural vari-ations of the cellulosic polysaccharides were elucidated by using the techniques: scanning electron microscope (SEM), high-performance anion-exchange chromatography, Fourier transform (FT-IR) spectrometer, carbon-13 nuclear magnetic resonance (CP/MAS 13C-NMR), and thermal gravimetric analysis. The pyrolysisgas chromatography-mass spectrometry (Py-GC/MS) characterized and verified the chemical composition obtained from the polysaccharide degradation during roasting. The sugar analysis results showed that galacturonic acid, xylose, and rhamnose were more easily degraded than arabinose, galactose, glucose, and mannose. The morphology of the cellulosic polysaccharides shows irregular dispersed globular fragments after roasting by SEM observation. FT-IR and CP/MAS 13C-NMR spectra indicated the crystalline structure and linkages of the cellulose did not break down in comparison to amorphous cellulose that partly degraded. Abundant acetic acid and 3-furaldehyde were among the polysaccharide degradation products identified by Py-GC/MS. These chemical compounds were likely the significant contributors to caramelization and the Maillard reaction in sesame seed roasting.

Lignin from the Chinese quince (Chaenomeles sinensis) fruit offers a promising source of natural antioxidant for industrial applications. However, the utilization of Chinese quince fruit lignin is restricted by its inhomogeneous nature. Accordingly, Chinese quince fruit lignin was sequentially fractionated with organic solvents of increasing dissolving capacity to prepare homogeneous lignin fractions. The GPC (gel permeation chromatography) results showed that the molecular weights of lignin fractions increased from dichloromethane fraction to dioxane/water fraction. The five lignin fractions were also compared with respect to yield, carbohydrate content, thermal stability, inter-unit linkages, S/G ratios, and phenolic OH content. Among the five fractions, the ethyl acetate fraction showed a lower proportion of β-O-4′ linkages (48.4%), the highest thermal stability, the highest phenolic OH content (2.8 mmol/g), and the highest DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging index and reducing power. The high antioxidant performance of the ethyl acetate fraction implies that it can be used as a natural antioxidant. This study shows that sequential solvent fractionation of lignin can produce homogeneous fractions with enhanced antioxidant performance. In addition, it demonstrates that Chinese quince fruits are a potentially valuable natural resource.

The wet decortication of sesame seeds produces wastewater containing diverse minerals and organic pollutants that could be valuable resources for the food industry. This investigation aimed to reclaim, purify, and characterize the polysaccharides contained in the waste liquor from the sesame decortication industry. The purified polysaccharide fractions were characterized using monosaccharide analysis, GPC (high-performance gel permeation chromatography), FT-IR (Fourier-transform infrared) spectroscopy, methylation analysis, 1D and 2D Nucleai Magnetic Resonance (NMR) analysis, and thermal analysis. Four fractions were found (SSP-1,-2,-3, -4), of which SSP-2 was proportionately the largest and most interesting. The backbone of SSP-2 is mainly composed of (1→2,4)-β-D-Xylp residues with side chains connected to the O-4 position, with many T-β-D-Galp and (1→5)-α-L-Araf residues, and fewer (1→4)-α-D-Glcp, (1→2)-α-L-Rhap, T-α-L-Araf, and (1→2)-β-D-GlcpA residues. An efficient method for removing the polysaccharides would simplify wastewater treatment while finding a use for them would benefit the sesame, food, and pharmaceutical industries.

In this investigation, the hemicellulose fractions were isolated from sesame hulls before and after roasting at 160 °C, 180 °C, 200 °C, and 220 °C. The structural properties of the hemicelluloses were comparatively investigated by analytical techniques including FT-IR, sugar compositions analysis, molecular weight analysis, thermal analysis, and NMR. Roasting at temperatures from 180 to 220 °C resulted in higher yields of hemicelluloses subsequently isolated from sesame hulls by the alkaline method. The results of sugar analysis and average molecular weight analysis of the hull hemicelluloses revealed that the side chain sugar units such as arabinose and rhamnose of the hemicelluloses are more easily degraded after roasting during the roasting. That the main chains of hemicelluloses in the cell wall of sesame seed hulls did not change significantly. The investigation provides new information about the mechanisms of the structural changes that occur in sesame hull hemicelluloses during roasting.

Gelatinization and retrogradation characteristics of starches from tigernut (Cyperus esculentus) tuber before and after various oil extraction processes were studied in this investigation. The results indicated that starches isolated from tigernut tuber after the various oil extraction processes varied significantly in gelatinization and retrogradation properties. The starches isolated from the cakes of tigernut tuber after hot press extraction exhibited higher retrogradation tendency and relatively less shear-thinning than other starch samples. The results of FT-IR, XRD, and NMR analysis indicated that oil extraction had an unfavorable influence on starch retrogradation, which may be due to structural changes caused by oil extraction processes. In particular, oil extraction led to more efficient packing of double helices in the crystalline lamella of the starches during storage. Retrogradation of the starch gels also reduced the water holding capacities of the starches. The starch sample isolated from the cake after cold press extraction exhibited the highest water absorption capacity among the five samples for all storage times. This investigation provides valuable novel information for the industrial utilization of tigernut tuber starches isolated from meals and cakes after oil extraction.

Chinese quince fruits are rich in proanthocyanidins (PAs), which have antioxidant properties. This work describes a method to isolate PAs from Chinese quince fruits by a combination of ball-milling and enzyme hydrolysis pretreatments. The yield, total PA and total phenolic contents, structural characteristics, antioxidant activity, and α-amylase inhibitory activity of different pretreated PA samples were determined and analyzed. Among them, the ball-milling combined with multi-enzyme (cellulase, xylanase, and pectinase) hydrolysis pretreated sample (BEP-4) was the most outstanding. The yield of BEP-4 could be improved up to 7.72%, which was 2.51 times higher than that of the conventional organic solvent extraction method (3.02%). It had the highest total phenols and PAs content of 750.98 ± 6.95 and 948.72 ± 3.50 mg/g extract, respectively. The thermal stability and molecular weight (9610 Da) of BEP-4 were lower than other fractions. BEP-4 contained a high proportion of PC structure (98.35%) and flavan-3-ol content (87.88%). It also had the highest antioxidant capacity with IC50 values of 131.45 ± 0.97, 22.66 ± 0.32, 134.05 ± 0.71, and 182.07 ± 0.28 μg/mL for DPPH, ABTS, hydroxyl radical scavenging capacity, and α-amylase inhibiting capacity, respectively. These investigations provide a new, efficient way to isolate PAs from Chinese quince fruits, and reveal that Chinese quince fruits may be a good source of antioxidants, worthy of further development.

The effects of extraction conditions on the yield of polysaccharides from the fruit of Chaenomeles sinensis (FCS) using a hot compressed water method were investigated. The results showed that an appropriately high temperature (150 °C) and a moderate extraction time (45 min) at a material to water ratio of 1 to 10 g/mL led to a high yield of alcohol precipitation polysaccharide (PA). The purified polysaccharides (CSP-1, CSP-2, and CSP-3) were successfully obtained using a DEAE-52 chromatographic column. Chemical analysis showed that CSP-2 and CSP-3 were homogenous and exhibited characteristics of esterified pectins, whereas CSP-2 mainly consisted of galacturonic acid (GalA), galactose (Gal), arabinose (Ara), rhamnose (Rha), and mannose (Man) with an average molecular weight of 59.1 kDa. Furthermore, CSP-1 possessed stronger antioxidant ability according to DPPH scavenging and reducing power compared with CSP-2 and CSP-3. However, it was weaker with respect to OH scavenging. The technical data presented in this study could help the industry make use of polysaccharides from FCS as a source of pectin for a range of pharmaceutical, culinary, and cosmetic products.

In this work, sesame oligosaccharides (SOL) and sesame protein isolate (SPI) were isolated from dehulled sesame meal, combined and then tested as a sesame model system, to investigate the effects of roasting temperature and duration on color and flavor. The results demonstrated that SOL was more easily degraded than SPI; specifically, SOL and SPI gradually degraded at 100 °C and 150 °C, respectively. FT-IR analysis showed that characteristic bonds existing in the roasted samples were somewhat destroyed. Galactose, fructose, lysine, cysteine, and arginine showed great reduction and played an important role in color variation and flavor compound formation according to monosaccharide and amino acid analysis. Total color difference (

The safety problems related to the occurrence of benzo(a)pyrene in edible oil have been a major threat to human health, and now significant attention has been to remove benzo(a)pyrene. So in this work, cellulose, hemicellulose, and lignin biochars were prepared, and then were used to remove benzo(a)pyrene from contaminated oil. Based on the nitrogen adsorption/desorption isotherms and the scanning election micrographs, the modified biochars had a huge specific surface area of 983.50-1915.55 m2/g and a well-developed porous structure. The modified biochars showed higher removal rate for benzo(a)pyrene than unmodified biochars. The highest adsorption (95.79%) of benzo(a)pyrene was achieved using the modified lignin biochar, which was therefore selected for evaluation of adsorptive capacity. The ability of the modified lignin biochar to adsorb benzo(a)pyrene was consistent with the pseudo-second order kinetic equation indicating mainly chemisorption, and it fit the Freundlich isotherm (R2 > 0.999), thereby revealing the occurrence of multilayer adsorption. The effect of π-π conjugation interaction and pore-filling together promoted the high adsorption performance of the modified lignin biochar. This work demonstrates that the modified lignin biochar could be a promising adsorbent for the removal of benzo(a)pyrene from edible oils.

Over the years, concentrated efforts have been directed toward the improvement of desirable characteristics and attributes in peanut cultivars. Most of these breed improvement programs have been targeting attributes that involve peanut growth, productivity, drought and disease tolerance, and oil quality and content, with only a few articles focusing directly on improvements in peanut butter organoleptic qualities. There are numerous peanut cultivars on the market today, with widely differing chemical compositions and metabolite profiles, about which little is known concerning their suitability for making peanut butter. In this review, we detail how the numerous peanut varieties on the market today, with their genetically conferred physiochemical attributes, can significantly affect the sensory quality attributes of peanut butter, even in peanut butter processing lines with optimized processes. If other peanut butter processing parameters are held constant, variations in the chemical composition and metabolite profiles of peanuts have a significant impact on peanut butter color, flavor, texture, storage stability, shelf life, and overall product acceptance by consumers. Further research on breeding programs for peanut varieties that are specifically tailored for peanut butter production, and even more comprehensive research on the synergetic relationship between peanut chemical composition and peanut butter organoleptic quality, are still required.

Complete utilization of tigernut tubers, including their use in oil production and use of the meal as a byproduct, is an important aspect in improving their industrial value. However, there are few studies on the use of starch isolated from tiger tuber meals and cakes remaining after oil extraction. In this investigation, starches were isolated from tigernut tubers before and after various oil extraction processes and their structural and functional properties were comparatively investigated. A typical C-type X-ray diffraction pattern was observed for all of the isolated starches. Noticeable decreases in relative crystallinity by XRD and solid state 13C NMR were observed for starches from the cakes of tigernut tubers remaining after oil extraction utilizing a mechanical expeller. The proportion of amorphous phase (PPA) in the starches isolated from meals and cakes was relatively low compared with that of starch isolated from raw tigernut tuber. The branch-chain length distribution of the starches isolated from meals and cakes exhibited a low average chain length of amylopectin. These changes reflect a disruption in the ordered structure of starch granules caused by the various oil extraction processes, which led to significant variability in their functional properties, including paste clarity, freeze-thaw characteristics, thermal transition temperatures, texture, solubility, and swelling power. This investigation provides important information for the complete utilization of tigernut tubers.

Enzyme-assisted extraction is a powerful technology for polysaccharides from plant materials. In the present investigation, the emulsifying properties of Chinese yam polysaccharides extracted by enzyme-assisted methods were determined and compared to the properties of polysaccharide fractions isolated by conventional hot water method. The structural properties of the various polysaccharide fractions were also investigated to understand their relationships with emulsifying properties. Results showed that the polysaccharide fractions extracted by papain hydrolysis exhibited relatively better emulsifying activities and stability. According to particle size distribution and gravitational phase separation experiments, PA12 exhibited the best emulsifying capacity and stability among the various polysaccharide fractions. All of the polysaccharide fractions differed from each other with respect to monosaccharide composition, free amino acid distribution, molecular weight, and flow behavior; these differences influenced the emulsifying properties of the polysaccharide fractions. The results obtained provide important information for choosing appropriate polysaccharide-based emulsifiers for food processing and other applications.

The aim of this investigation was to characterize oils extracted from pepper seed (Capsicum annuum L.) by subcritical propane at various stages of the extraction. During the extraction, the pepper seed oil (PSO) was sampled at five different times. The various oil fractions were named: PSO-1 (0–3 min), PSO-2 (4–6 min), PSO-3 (7–9 min), PSO-4 (10–12 min), and PSO-5 (13–15 min). Results showed that 97.2% of total oil content was extracted before PSO-4. There were no significant difference in fatty acid composition between the oil samples; however, results show that extraction time did significantly affect other chemical constituents (i.e., tocopherols, sterols, and volatile flavor compounds), and thermal stability. This investigation provides important information for the application of pepper seed and for further development of subcritical fluid extraction.

This work focused on how roasting changed the chemical components of chili (Capsicum annuum L.) seeds and how it affected the stability of chili seed oils during storage. The oils from chili seeds before and after roasting treatments were stored at 63 °C for 30 days and then analyzed. Results showed that roasting changed the main sugars compositions and amino acid compositions (total content decreased from 15.9 to 7.4%), which confirmed that it could form brown pigments and volatile flavor compounds in pepper seeds after roasting. Compared with oil from unroasted seeds, oils from roasted seeds had greater oxidative stability and maintained greater antioxidant capacity during storage. These effects were possibly due to the synergistic of the neo-formed products by Maillard reaction, vitamin E, and other bioactive components. This investigation showed that roasting treatment could be considered as an appropriate method for extending the storage stability of chili seed oils. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10068-019-00578-9) contains supplementary material, which is available to authorized users.

Peanut butter has a very large and continuously increasing global market. The food safety risks associated with its consumption are also likely to have impacts on a correspondingly large global population. In terms of prevalence and potential magnitude of impact, contamination by Salmonella spp., and aflatoxins, are the major food safety risks associated with peanut butter consumption. The inherent nature of the Salmonella spp., coupled with the unique chemical composition and structure of peanut butter, present serious technical challenges when inactivating Salmonella spp. in contaminated peanut butter. Thermal treatment, microwave, radiofrequency, irradiation, and high-pressure processing all are of limited efficacy in inactivating Salmonella spp. in contaminated peanut butter. The removal of aflatoxins in contaminated peanut butter is equally problematic and for all practical purposes almost impossible at the moment. Adopting good manufacturing hygiene practices from farm to table and avoiding the processing of contaminated peanuts are probably some of the few practically viable strategies for minimising these peanut butter food safety risks. The purpose of this review is to highlight the nature of food safety risks associated with peanut butter and to discuss the effectiveness of the initiatives that are aimed at minimising these risks.

Asarinin, an isomer of sesamin, has attracted attention because it has stronger biological properties than sesamin. The research on the conversion of sesamin into asarinin is limited. In this study, solid acid catalysts were screened and applied to promote the conversion of sesamin into asarinin in sesame oil. The results showed that citric acid loaded on zeolite beta (CTAH) was the optimal catalyst for asarinin production among the prepared catalysts. Characterization showed that CTAH had the greatest pore volume, largest surface area and strongest acid content. Response surface methodology (RSM) was applied to optimize the reaction conditions for asarinin yield using CTAH. The optimal reaction conditions were as follows: temperature, 85 °C; time, 2.7 h; catalyst amount, 1.6%. The predicted and experimental values of asarinin yield were 50.79 and 51.80 mg/100 g, respectively. The peroxide value and color in sesame oil samples treated with CTAH were clearly improved. In short, CTAH is a solid acid catalyst with potential application in the industrial conversion of sesamin into asarinin and in the improvement of sesame oil.

This was the first study to compare the key aroma-active compounds that contributed to the different aroma profiles between roasted and cold-pressed sesame oils. Aroma compounds were extracted by headspace solid-phase micro-extraction (HS-SPME) and simultaneous distillation extraction (SDE) and were analysed using gas chromatography–olfactometry-mass spectrometry (GC-O-MS) and aroma extract dilution analysis (AEDA). The numbers of aroma-active compounds with the flavour dilution (FD) factors between 1 and 2048 were 57 and 16 in the roasted and cold-pressed sesame oils, respectively. A total of 28 volatile compounds were identified as aroma-active compounds in sesame oils for the first time. Important aroma compounds (FD ≥ 8) were quantified by the external standard method, and their odour activity values (OAV) were calculated as the ratio of their concentrations to odour thresholds in oil. The numbers of key aroma-active compounds defined by OAVs ≥ 1 were 23 (OAVs = 1–385) and 8 (OAVs = 1–42), respectively, in the roasted and cold-pressed sesame oils. 2-Methoxy-4-vinylphenol (smoked, 1924 µg/kg, OAV = 385), 2-methoxyphenol (smoked, 1488 µg/kg, OAV = 114) and pyrazines (roasted and nutty, 578–22750 µg/kg, OAV = 1–67) were the most important aroma-active compounds in the roasted sesame oil, whereas hexanal (green and fruity, 3094 µg/kg, OAV = 42) was the most important aroma-active compound in the cold-pressed sesame oil, followed by (E,E)-2,4-decadienal (earthy, 4170 µg/kg, OAV = 31), dimethyl sulfone (sulphur-like, 406 µg/kg, OAV = 20) and octanal (green and fruity, 901 µg/kg, OAV = 16). This study provides valuable information for manufacturers to achieve precise flavour control of sesame oil products.

Chinese quince fruits (Chaenomeles sinensis) have an abundance of lignins with antioxidant activities. To facilitate the utilization of Chinese quince fruits, lignin was isolated from it by auto-catalyzed ethanol organosolv pretreatment. The effects of three processing conditions (temperature, time, and ethanol concentration) on yield, structural features and antioxidant activities of the auto-catalyzed ethanol organosolv lignin samples were assessed individually. Results showed the pretreatment temperature was the most significant factor; it affected the molecular weight, S/G ratio, number of β-O-4' linkages, thermal stability, and antioxidant activities of lignin samples. According to the GPC analyses, the molecular weight of lignin samples had a negative correlation with pretreatment temperature. 2D-HSQC NMR and Py-GC/MS results revealed that the S/G ratios of lignin samples increased with temperature, while total phenolic hydroxyl content of lignin samples decreased. The structural characterization clearly indicated that the various pretreatment conditions affected the structures of organosolv lignin, which further resulted in differences in the antioxidant activities of the lignin samples. These results can be helpful for controlling and optimizing delignification during auto-catalyzed ethanol organosolv pretreatment, and they provide theoretical support for the potential applications of Chinese quince fruits lignin as a natural antioxidant in the food industry.

This investigation was carried out to offer insight into the formation and antioxidant activity of Maillard reaction products (MRPs) derived from various sugar-amino acid model systems active in the roasting of sesame seeds. Reducing sugars (glucose, fructose, and xylose) and amino acids (serine, cystine, arginine, and lysine) present in sesame seeds were used to prepare the MRPs at various reaction times, and then the effect of reaction time on the MRPs derived from the various model systems was investigated. Within the first 15 min, the amounts of free amino groups decreased around 40% remaining amino groups of Lys-sugar model and around 75% remaining amino groups of Arg-sugar model. Results indicated that reducing sugar and free amino groups decreased obviously in Lys- and Arg-model systems. Based on correlation coefficient of antioxidant activities assessment and MRP formation in the Lys- and Arg-model systems above 0.978 and an extremely significant correlation in Pearson test exists, a conclusion could be made that these model systems are critical contributing factors in MRP formation during the roasting of sesame seeds. These findings offer insight into the formation and antioxidation of MRPs during the sesame seeds roasting.

Corn hulls were abundant and inexpensive byproducts of the corn dry or wet milling processes, but most of them were discarded as agro-wastes. The aim of this study was to extract the dietary fiber by hot-compressed water (HCW) from defatted corn hull and to determine the chemical properties. Results showed that temperature and time played critical roles in extraction efficiency; the maximal yield of dietary fiber A (DFA) extracted by HCW reached 33.0% at 150°C for 60 min. The yield of dietary fiber B (DFB) increased from 2.0% to 56.9% as the temperature increased from 110 to 180°C, while the yield of solid residue (SR) decreased from 88.7% to 27.7%. Fourier transform infrared spectroscopy (FT-IR) results demonstrated that C-H, O-H, C=O, COO- occurred in the DFA, SR and DFB. The dietary fiber polysaccharides consisted of arabinose, galactose, glucose, xylose and uronic acid.

Chinese quince seed gum (CQSG) is a novel potential viscosifier or stabilizer with good storage stability. In this work, CQSG was extracted from the surface of Chaenomeles sinensis (Chinese quince) seeds, and purified by DEAE-Sepharose Fast-Flow and Sephacryl S-400 HR chromatography; three fractions were obtained (CQSG-1, -2, -3). The main fraction (CQSG-2) was investigated by monosaccharide analysis, methylation and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) experiments to determine its structure. Results showed that CQSG-2 is composed of arabinose (Ara), glucose (Glu), xylose (Xly), galacturonic acid (Gala) and glucuronic acid (Glua) in a molar ratio of 4.0:0.3:15.2:4.2:3.8. →4-β- d -Xylp-1→ and →2, 4-β- d -Xylp-1→ constitute the backbone in a ratio of 5.9:4.5, and the Arap-1→, α- d -GalpA-1→, →2-α- d -GlcpA-1→, →4-β- d -Glcp-1→, and →2, 3, 5- l -Araf-1→ form the branched chain. The molecular aggregation of CQSG-2 with high molecular weight (Mw) (1.4 × 106 Da) was strong compared with CQSG-1 and CQSG-3. This is the first systematic elucidation of the structure of Chinese quince seed gum, and it provides the basis for developing applications for this gum in the food and pharmaceutical industries.

Two-step isolation of hemicelluloses from Chinese quince fruit was carried out in this investigation. At the first treatment stage, hydrothermal treatment was developed to enhance the xylose amount in the solid residue remaining after pectin extraction. Second, the alkali-extractable hemicelluloses were isolated from the solid residue obtained from hydrothermal treatment and were successively sub-fractionated by precipitation at graded ethanol concentrations of 30%, 50%, 70% and 90%. The structural properties of the isolated hemicelluloses from raw fruits and fruits treated with the hydrothermal process were characterized by sugar analysis, FT-IR, molecular weights, thermo-gravimetric analysis, morphological analysis, and NMR. Results showed that the xylose amount in the solid residue increased from 58.2% to 62.2% when the hydrothermal treatment temperature was increased from 120 °C to 150 °C. Arabinose and mannose were found to be hydrolyzed by hydrothermal treatment, while the crystalline cellulose and lignin were not affected. Compared with the raw Chinese quince, the treatment had an important effect on the sugar composition distributions and average molecular weights of hemicelluloses obtained at various ethanol concentrations. Structural characterization revealed that the isolated hemicellulosic sub-fractions precipitated at a final ethanol concentration of 30% had a backbone of d -xylose residues with a β-(1 → 4)-linkage. This work reveals a novel hemicelluloses isolation route from Chinese quince fruit, which was important in the development of biomass refining industry. This work reveals a novel hemicelluloses isolation route from Chinese quince fruit, which was important in the development of biomass refining industry.