Highly efficient isolation and purification of high-purity tea saponins from industrial camellia oil production by porous polymeric adsorbents.

BACKGROUND: Recovery of high-purity tea saponin (TS), a promising non-ionic surfactant with well-documented properties, is one of the major challenges to broadening its industrial applications. In this study, an innovative and sustainable strategy for the highly-efficient purification of TS was developed by using well-designed highly-porous polymeric adsorbents. RESULTS: The prepared Pp-A with controllable macropores (~96 nm) and appropriate surface hydrophobic properties was found more favorable for achieving high adsorption efficiency towards TS/TS-micelles. Kinetic results showed the adsorption follows the pseudo-second-order model (R2 = 0.9800), and the Langmuir model is more qualified to explicate the adsorption isotherms with Qe-TS ~ 675 mg g-1 . Thermodynamic studies revealed the monolayer adsorption of TS was an endothermic process that was conducted spontaneously. Interestingly, ethanol-driven desorption (90% v/v ethanol) of TS was rapidly (< 30 min) complete due to the possible ethanol-mediated disassembling of TS-micelles. A possible mechanism that involves the interactions between the adsorbents and TS/TS-micelles, the formation and disassembling of TS-micelles was proposed to account for the highly efficient purification of TS. Afterwards, Pp-A-based adsorption method was developed to purify TS directly from industrial camellia oil production. Through selective adsorption, pre-washing, and ethanol-driven desorption, the applied Pp-A enabled the direct isolation of high-purity TS (~96%) with a recovery ratio > 90%. Notably, Pp-A exhibited excellent operational stability and is of high potential for long-term industrial application. CONCLUSION: Results ensured the practical feasibility of the prepared porous adsorbents in purifying TS, and the proposed methodology is a promising industrial-scale purification strategy. © 2023 Society of Chemical Industry.

Radio frequency as an innovative method to produce low-fat French fries.

BACKGROUND: A large amount of evidence shows that excessive fat intake can increase the risk of obesity, type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular disease. The main purpose of this study was to use radio frequency (RF) technology to prepare low-fat French fries. RESULTS: RF treatment for 10 min significantly decreased the force required to cut potatoes and inhibited the enzymatic browning of fresh-cut potatoes. Moreover, RF treatment increased the hardness, gumminess, and chewiness of French fries from 388.55 g, 85.67, and 33.27 to 776.93 g, 159.36, and 70.11, respectively. Furthermore, RF treatment for 10 min reduced the oil content of French fries by 28.0% compared to that of the control group. This result was related to the pre-gelatinized potato starch content after RF treatment. Pre-gelatinized starch forms a 'protective film', that prevents oil from entering the fries during frying. CONCLUSION: Moderate RF treatment (10 min) reduced the oil content of French fries without making their texture significantly different from that of commercial French fries. These findings may provide a new perspective for the application of RF technology in the development of low-fat fried foods. © 2022 Society of Chemical Industry.

Effects of pulse electric field pretreatment on the frying quality and pore characteristics of potato chips.

The main purpose of this work was to investigate the effect of pulsed electric field (PEF) treatment on the oil absorption capacity of potato chips, evaluated via changes to microstructure and pore characteristics. Our results showed that as electric field strength increased from 0 kV/cm (no pretreatment) to 5 kV/cm, the oil content of potato chips decreased by up to 20.6%. Furthermore, at higher the electric field strengths (5 ~ 20 kV/cm), most of the potato cell walls collapsed, and dense pores could be observed in the horizontal profile of the chips. Moreover, some smaller pores (10-50 nm) in the potato chips were disrupted and merged into larger pores (50-100 nm), thus increasing the total volume and average diameter of the pores, accelerating moisture evaporation and reducing oil absorption during frying. Our findings provide a novel perspective on the application of PEF towards the development of lower-fat and healthier fried foods.

Systematic Review of Tongxinluo Capsule on the Therapeutic Effect and Hemorheology of Patients with Transient Ischemic Attack.

OBJECTIVES: This study aims to systematically evaluate the clinical efficacy of Tongxinluo capsule in the treatment of transient ischemic attack (TIA) and its effect on hemorheology, thereby providing scientific basis for clinical decision making. METHODS: A comprehensive and systematic literature retrieval was conducted in the CNKI, Wanfang database, SinoMed, EMbase, and PubMed to screen the randomized controlled trials (RCTs) of Tongxinluo capsule in the treatment of TIA. The retrieval time was from the inception of each database to September 10, 2020. Endnote X9 was used to screen the literature. Cochrane Collaboration tool for assessing risk of bias was used to evaluate the quality of the included studies. Stata16.0 statistical software was used for meta-analysis. RESULTS: A total of 12 RCTs were included, involving 946 subjects. (1) The clinical efficacy of the Tongxinluo group was better than that of the control group (RR = 1.19, 95% CI (1.09, 1.30), P ≤ 0.001). (2) The hemorheological characteristics of the Tongxinluo group were significantly improved compared with those of the control group (whole blood high shear viscosity: SMD = -1.61, 95% CI (-1.89, -1.34); P ≤ 0.001, whole blood low shear viscosity: SMD = -1.06, 95% CI (-1.31, -0.80), P ≤ 0.001, fibrinogen: SMD = -1.12, 95% CI (-1.94, -0.29), P = 0.008, plasma specific viscosity: SMD = -1.00, 95% CI (-1.69, -0.31), P = 0.004, and hematocrit: SMD = -1.47, 95% CI (-2.16, -0.77), P ≤ 0.001). (3) There was no significant difference in the incidence of adverse reactions between the Tongxinluo group and control group (RR = 7.76, 95% CI (0.98, 61.28), P = 0.052). CONCLUSION: Tongxinluo capsule is superior to conventional treatment in improving clinical overall response rate and hemorheological indexes and is relatively safe. Due to the deficiencies of the existing studies, more high-quality studies with rigorous design are required for further verification.

A novel hypoglycemic agent: polysaccharides from laver (Porphyra spp.).

Type-II diabetes mellitus (T2DM) has become one of the most prevalent diseases on Earth and some treatments have been developed to manage it. One intestinal enzyme α-amylase can break down starch to glucose. Inhibiting its activity will control blood glucose and provide an essential approach for the management of T2DM. Alpha-amylase inhibitor (α-AI) specifically inhibits the activity of α-amylase, and reduces the blood glucose level efficiently. To develop a novel α-AI, the red seaweed laver (Porphyra spp.) was exploited in this work, whose extracts contain polysaccharides showing an inhibitory effect against α-amylase. The crude polysaccharides were extracted using hot water (85 °C) and degraded to low-molecular-weight polysaccharides with 7% of H2O2. One polysaccharide PD-1 exhibiting a competitive binding mode with an IC50 of 12.72 mg mL-1 was separated from these degraded polysaccharides, showing approximately 98.78% of α-amylase inhibition activity. In vivo, PD-1 could efficiently suppress postprandial blood glucose levels in normal and diabetic rats. The polysaccharide inhibitor from red seaweed laver could be regarded as a novel functional food ingredient in T2DM management.

Fate of phospholipids during aqueous extraction processing of peanut and effect of demulsification treatments on oil-phosphorus-content.

PC (phosphatidylcholine), PE (phosphatidylethanolamine), PI (phosphatidylinositol), and PA (phosphatidic acid) in 9 peanut matrices obtained during the AEP (aqueous extraction processing) of peanut were quantified employing HPLC-ELSD analysis in this study. Phosphorus contents of crude oils obtained from different demulsification treatments were also investigated. Decantation had a larger effect than grinding in terms of phospholipids loss due to alkaline-hydrolysis, indicating this processing step was vital for the manipulation of phospholipids levels remained in oil. Over 80% of initial phospholipids were lost during AEP and only 19.8% of initial phospholipids ended up in cream, skim and sediment phase. 52.55% of the remained phospholipids trapped in cream phase. Just 22.16-32.61 mg/kg phosphorus content could be detected in crude oils, which indicated the separation of phospholipids from the cream phase into aqueous medium. Degumming was not essential in AEP of peanut and the waste generated after demulsification could be a source of phospholipids.

Extraction of sunflower head pectin with superfine grinding pretreatment.

Effect of superfine grinding on pectin extraction was investigated. Sunflower heads were grinded into microparticles of ~50 µm, thus pectin chains were fully exposed due to cell wall breakdown. A good pectin yield of 14.5 ± 0.36% (w/w) was subsequently achieved at mild conditions (pH 5.0, 25 °C, 2 h) associated with 0.8% (w/v) sodium citrate (SC). However, the molecule weight of pectin was greatly reduced (Mw = 7.87 ± 0.21 kDa) due to the action of endo-pectinases. With heating (pH 5.0, 85 °C for 20 min, 25 °C for 1.5 h) the endo-pectinases were effectively inhibited, thus Mw was increased to 338.07 ± 12.37 kDa. With superfine grinding, pectin extracted with different conditions presented various properties. Pectin extracted at pH 2.5 had higher esterification degree (DE, ~40%) and gelled at 3% (w/v) concentration. In contrast, pectin extracted under mild condition with low DE (21%) cannot gel at the same concentration. Conclusively, superfine grinding has potential application in pectin extraction.

Interfacial properties of ultrahigh methoxylated pectin.

The interfacial properties of ultrahigh methoxylated pectin (UHMP) prepared via esterification of citrus pectin (CP) were investigated. The intrinsic viscosity ([η]) of pectin was significantly decreased from 1211.5 mL/g to 294.9 mL/g as the degree of methylation (DM) increased from 63.18 ± 0.08% to 91.52 ± 0.11%. Surface tension (γ) analysis indicated that UHMP had a critical micelle concentration (CMC) of 0.8 g/L, which was slightly smaller than that of sugar beet pectin (SBP) (1.0 g/L). The morphology of the UHMP aggregation presented a network structure and irregular clusters at 10 µg/mL and 1 µg/mL based on atomic force microscopy (AFM). Transmission electron microscopy (TEM) observations further confirmed the self-aggregation behaviours and rod-like micelles of UHMP. The surface excess (Γ) was 1.69 ± 0.17 µmol/m2 for UHMP, which was lower than the values of SBP (1.88 ± 0.21 µmol/m2) and CP (2.91 ± 0.57 µmol/m2). Correspondingly, UHMP possessed the highest molecular area (A) of 0.99 ± 0.10 nm2. Thus, UHMP was proposed to be more flexible and extendable at the interface. The interfacial shear rheology study suggested that UHMP was able to form an elastic-dominant interfacial film to stabilize the oil/water interface.

Emulsions prepared by ultrahigh methoxylated pectin through the phase inversion method.

Ultrahigh methoxylated pectin (UHMP) was prepared by esterification of citrus pectin in absolute methanol at 60 °C for 12 h, whereby its methoxylation degree was increased from 63.18 ±â€¯0.08% to 91.20 ±â€¯0.13%, and its molecular weight was reduced from 64,400 g/mol to 15,000 g/mol. Structural modifications improved UHMP solubility by over 5%(w/v) and resulted in a flat reduced viscosity profile that was slightly affected by pectin concentration increase and pH change. Interfacial activity of UHMP was improved since most of the galacturonic acid (GalA) units had one methyl group and two hydroxyl groups. Dynamic interfacial tension analysis indicated that UHMP was adsorbed at O/W interface faster than mother pectin with a better capacity to reduce the initial interfacial tension. UHMP emulsions prepared by phase inversion method at different solid-to-oil ratios (20-50%) had a small Z-average size of approximately 400 nm with a creaming index (CI) of 17-20%. During long-term storage (56 days), droplet size and CI were monitored every 7 days, and results suggested that UHMP emulsions were stable. UHMP emulsions showed good pH stability after 14-days storage in a wide pH range of 2-8 without droplet coalescence. Thermal treatment at 85 °C accelerated the flotation of large droplets but did not break droplets.

Combination of thermal pretreatment and alcohol-assisted aqueous processing for rapeseed oil extraction.

BACKGROUND: The alcohol-assisted aqueous extraction processing (AAEP) of oil has many advantages such as no need for demulsification and relative low cost compared with enzymatic aqueous extraction processing (EAEP). Three kinds of thermal pretreatments including dry-heating, wet-heating and soak-heating followed by the AAEP of rapeseed oil were investigated. RESULTS: Both soak-heating and wet-heating had a higher contribution rate to oil yield than dry-heating due to the enhancement of heat transfer rate owing to the high moisture content in the rapeseed cells. However, oil from soak-heated rapeseeds showed a much lower level on peroxide value (0.41 mmol kg-1 ) than that of wet-heated rapeseeds (5.23 mmol kg-1 ). In addition, transmission electron microscopy images illustrated that promoting effects of soak-heating and wet-heating on oil release were attributed to the coalescence of oil bodies. A relative low concentration of alcohol solution as an extraction medium, the highest oil recovery of 92.77% was achieved when ground rapeseeds (mean particle size: 21.23 µm) were treated with 45% (v/v) alcohol for 2 h at 70 °C and pH 9.0. Both the acid value and the peroxide value are lower than the commercial oil produced by extrusion and hexane extraction. Furthermore, the oil produced from AAEP also had higher content of tocopherols and lower content of trans-fatty acids than the commercial oil. CONCLUSION: AAEP of oil from soak-heated rapeseeds is a promising alternative to conventional oil extraction methods. © 2019 Society of Chemical Industry.

Characterization of natural low-methoxyl pectin from sunflower head extracted by sodium citrate and purified by ultrafiltration.

Sunflower head pectin was extracted by 0.6% (w/v) sodium citrate under 85°C, 3.5h with a solid to liquid ratio of 1:40, giving the maximum uronic acid yield of 16.90% (w/w). The extract was purified by an ultrafiltration membrane with the molecular weight cut-off of 8000 Da and dried by spray-drying to obtain SFHP(A) powders with particle diameters of 2-5 µm. In comparison to the SFHP(B) extracted by ammonium oxalate and isolated by alcohol, SFHP(A) had a close DM (22.56%) but a considerably lower DAm (3.42%). HPSEC-MALLS analysis suggested that SFHP(A) has undergo a deeper degradation resulting in smaller Mw and Mn. HPAEC-PAD showed that SFHP(A) contains more neutral sugars since the degraded RG fragments have been retained during ultrafiltration. Finally, pectin aggregation in aqueous was investigated by FEG-SEM, which reveals that pectin network structure is constructed by microfilaments via coiling, intertwining and crosslinking.

Innovative assistant extraction of flavonoids from pine (Larix olgensis Henry) needles by high-density steam flash-explosion.

High-density steam flash-explosion (HDSF) was first employed to extract flavonoids from pine needles. The HDSF treatment was performed at a steam pressure of 0.5-2.0 MPa for 20-120 s. Scanning electron microscopy and high-performance liquid chromatography combined with photodiode-array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS) were used to characterize the morphological changes and analyze flavonoids of pine needles before and after HDSF treatment. Our results indicated that, after steam explosion at 1.5 MPa for 60 s, the flavonoids extracted reached 50.8 rutin equivalents mg/g dry weight, which was 2.54-fold as that of the untreated sample. HDSF pretreatment caused the formation of large micropores on the pine needles and production of particles, as well as the removal of wax layers. Compared to microwave-assisted, ultrasound-assisted, and solvent extraction, HDSF pretreatment took only 30 min to reach a maximum yield of 47.0 rutin equivalents mg/g flavonoids extract after pine needles were treated at 1.5 MPa for 80 s. In addition, after HDSF treatment, the aglycones were 3.17 times higher than that of untreated pine needles, while glycosides were lower by 57% (in HPLC-DAD individuals' sum) due to hydrolysis of flavonoids glycosides. It can be concluded that HDSF is a practical pretreatment for extraction of flavonoids and conversion in the healthy food and pharmaceutical industries.

Electrochemical reaction and oxidation of lecithin under pulsed electric fields (PEF) processing.

Pulsed electric fields (PEF) processing is a promising nonthermal food preservation technology, which is ongoing from laboratory and pilot plant scale levels to the industrial level. Currently, greater attention has been paid to side effects occurring during PEF treatment and the influences on food qualities and food components. The present study investigated the electrochemical reaction and oxidation of lecithin under PEF processing. Results showed that electrochemical reaction of NaCl solutions at different pH values occurred during PEF processing. Active chlorine, reactive oxygen, and free radicals were detected, which were related to the PEF parameters and pH values of the solution. Lecithin extracted from yolk was further selected to investigate the oxidation of food lipids under PEF processing, confirming the occurrence of oxidation of lecithin under PEF treatment. The oxidative agents induced by PEF might be responsible for the oxidation of extracted yolk lecithin. Moreover, this study found that vitamin C as a natural antioxidant could effectively quench free radicals and inhibit the oxidation of lipid in NaCl and lecithin solutions as model systems under PEF processing, representing a way to minimize the impact of PEF treatment on food qualities.

Cold storage temperature following pulsed electric fields treatment to inactivate sublethally injured microorganisms and extend the shelf life of green tea infusions.

In this work microbiological shelf life of green tea infusions processed by pulsed electric fields (PEF) treatment (38.4 kV/cm for 200 micros) were assessed at the three storage temperatures of 4, 25 and 37 degrees C, respectively. Immediately after PEF treatment, no viable bacterial cells were detected. However, significant recovery was observed during storage at 25 and 37 degrees C. The total aerobic microbial population increased rapidly in PEF-treated green tea infusions when stored at 25 and 37 degrees C for 14 and 7 days respectively. However, the microbial population remained under 1 log(10) CFU/ml when stored at 4 degrees C up to 180 days. These results demonstrated that a certain proportion of microbial cells in green tea infusions were sublethally injured by PEF treatment, and the recovery of apparently dead or 'intermediately damaged' cells could increase the detected number of surviving microorganisms. In the present study PEF-treated green tea infusions were placed at 4 degrees C for various time, and then stored at 37 degrees C. Cold storage (4 degrees C for 7 days) following PEF treatment was found to be effective to delay or inhibit the repair process of sublethally injured cells and extend the microbiological shelf life of PEF-treated green tea infusions to more than 90 days at 37 degrees C.