To develop value-added antioxidants from the peel and seeds of pomegranate marc, a by-product after pomegranate juice processing, the effects of drying before extraction and processing parameters on ...the extraction kinetics and product properties were systematically studied using water as an environmental friendly solvent for the extraction. The results showed that the drying process did not significantly affect the yield, content, and activity of antioxidants from either the peel or seeds. The antioxidants extracted from the peel had higher yield and content than those from the seeds. The yield and content of antioxidants increased with reduced particle size and increased water/sample ratio and temperature, but antioxidant activity was low when extraction temperature was high. By considering the antioxidant activity and operation cost, the recommended extraction conditions were peel particle size of 0.2
mm, water/peel ratio of 50/1 (w/w), temperature of 25
°C, and extraction time of 2
min, which gave the high antioxidant yield (11.5%) and content (22.9%), and DPPH scavenging activity of 6.2
g/g. Kinetic models were successfully developed for describing the extraction processes with different processing parameters.
•Alkaline concentration above 0.03M may cause nutrient or safety problems in extraction of rice residue protein.•Alkaline extraction may influence functional or structural properties of rice residue ...protein.•The LAL formation depends on the alkali concentration.
This study evaluated the nutrient property and safety of the rice residue protein isolates (RRPI) product (extracted by different alkali concentrations) by exploring the protein functional, structural properties and lysinoalanine (LAL) formation. The results showed that with the rising of alkali concentration from 0.03M to 0.15M, the solubility, emulsifying and foaming properties of RRPI increased at first and then descended. When the alkali concentration was greater than 0.03M, the RRPI surface hydrophobicity decreased and the content of thiol and disulfide bond, Lys and Cys significantly reduced. By the analysis of HPLC, the content of LAL rose up from 276.08 to 15,198.07mg/kg and decreased to 1340.98mg/kg crude protein when the alkali concentration increased from 0.03 to 0.09M and until to 0.15M. These results indicated that RRPI alkaline extraction concentration above 0.03M may cause severe nutrient or safety problems of protein.
•Combined polyphenol and ultrasound modification was incorporated into TSC-CTS film.•GA-UT modification increased tensile strength of the TSC-CTS film by 47.03%.•GA-UT modification improved ...antioxidant activity of the TSC-CTS film by 24.16 folds.•GA-UT modification reduced transmittance and permeability of the film by 29.26% and 15.70%.•GA-UT modified TSC-CTS films possessed improved antibacterial activity.
To produce an edible film with high mechanical and physicochemical properties, Tuna skin collagen-chitosan (TSC-CTS) composite films were prepared by incorporating ultrasound (UT) and pomegranate polyphenols including gallic acid (GA), tannic acid (TA), and ellagic acid (EA), respectively. The tensile strength and the DPPH scavenging activity of the GA-UT-TSC-CTS film (ultrasound frequency of 28 ± 0.5 kHz, power of 100 W/L, sweep frequency cycle of 100 ms, duty ratio of 77% and time of 10 min; GA concentration of 1.0 g/L and reaction time of 10 min) were increased by 47.03% and 24.16 folds, respectively compared to the control (TSC-CTS film). Meanwhile, light transmittance and water vapor permeability of the GA-UT-TSC-CTS film were decreased by 29.26% and 15.70%, respectively. These positive modification results were attributed to the altered structure during the film formation process, which were verified by Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), X-ray diffraction (XRD), and thermogravimetry results. Moreover, the GA-UT-TSC-CTS film possessed moderate thermal stability and color indexes and improved antibacterial activity. The antibacterial effect of the film against Bacillus subtilis was the highest, followed by Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus. Overall, the combination modification of gallic acid and ultrasound was an efficient modification method to improve the mechanical, antioxidant, and antibacterial properties of edible TSC-CTS films.
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•An ultrasound treated corn ACE inhibitory peptide-ferrous chelate was developed.•CP-Fe possessed ferrous content of 66.39% and ACE inhibition activity of 82.21%.•CP-Fe was formed by ...binding peptide amino, carbonyl and carboxyl groups with Fe2+.•CP-Fe was stable at various temperatures, pH and gastrointestinal environments.
In order to improve iron chelating ability and retain the activity of functional peptide, corn peptide was chelated with iron to form corn ACE inhibitory peptide-ferrous chelate (CP-Fe) treated by dual-frequency ultrasound. Furthermore, the chelating mechanism was revealed by analyzing various structural changes, and the stability was further evaluated. Under this study condition, the iron-binding capacity of corn ACE inhibitory peptide (CP) and chelate yield reached 66.39% and 82.87%, respectively. Ultrasound-treated CP exhibited a high iron chelating ability, meanwhile, chelation reaction had no significant effect on the ACE inhibition activity (82.21%) of the peptide. CP-Fe was formed by binding the peptides amino, carbonyl and carboxyl groups with Fe2+ demonstrated by Ultra-violet spectroscopy, Fourier transform infrared characterization, X-ray diffraction, energy dispersion spectrum, zeta potential, amino acid composition and other multi-angle analyses. Moreover, ultrasound-treated CP-Fe chelate exhibited porous surface and uniform nanoparticle shape. Furthermore, ultrasound-treated CP-Fe chelate exhibited an excellent stability towards various pH (retention rate ≥ 95.47% at pH 6–10), temperatures (retention rate ≥ 85.10% at 25–70 °C), and gastrointestinal digestion (retention rate 79.18%). Overall, ultrasound-treated CP-Fe chelate possessed high iron-chelating ability, ACE inhibition activity and stability. This study provides a novel synthesis method of the iron-chelating corn ACE inhibitory peptide, which is promising to be applied as iron supplements with high efficiency, bioactivity, and stability.
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•A new corn peptide-chelated calcium microcapsule supplement was prepared.•A method of dual frequency ultrasound has been developed to improve encapsulation.•Ultrasound significantly ...improved the encapsulation rate and yield of microcapsules.•Ultrasound modified microcapsule structure and reduced particle size.•Microcapsule showed high solubility, stability and good sustained release effect.
The utilization of peptide-chelated calcium is low due to the influence of factors such as solubility, heat and digestive environmental conditions; therefore, it is crucial to protect, prolong and stabilize this nutrient in order to enhance its efficacy. This study was conducted to prepare corn peptide-chelated calcium microcapsules using β-cyclodextrin (β-CD) as the wall material through an improved ultrasonic-assisted method. The structure, solubility, thermal stability, and in vitro gastrointestinal digestion of these microcapsules were thoroughly investigated and analyzed. The microcapsules were prepared using the following recommended conditions: a chelate concentration of 5 mg/mL, a mass ratio of chelate to β-CD of 1:8 g/g, and a synchronous dual-frequency ultrasound (20/28 kHz) at a power of 75 W, a duty ratio of 20/5 s/s, and a time of 20 min. These specific parameters were carefully selected to ensure the optimal fabrication of the microcapsules. The results showed that the utilization of dual-frequency ultrasound resulted in a significant increase in both the encapsulation rate and yield, which were enhanced by 15.84 % and 15.68 %, respectively, reaching impressive values of 79.17 % and 90.60 %. Moreover, the results of the structure index analysis provided further confirmation that ultrasonic treatment had a significant impact on the structure of the microcapsules, leading to a noticeable reduction in particle size and transformation into nanoparticles. Furthermore, the microcapsules demonstrated excellent solubility within a wide pH range of 2 to 10, with solubility ranging from 93.54 % to 88.68 %. Additionally, these microcapsules exhibited remarkable thermal stability, retaining a minimum of 84.8 % of their stability when exposed to temperatures ranging from 40 to 80 °C. Moreover, during gastric and intestinal digestion, these microcapsules exhibited a high slow-release rate of 44.66 % and 51.6 %, indicating their ability to gradually release calcium contents. The inclusion of dual-frequency ultrasound in the preparation of high calcium microcapsules yielded promising outcomes. Overall, our work presents a novel method for synthesizing corn peptide-chelated calcium microcapsules with desirable properties such as good solubility, excellent thermal stability, and a significant slow-release effect. These microcapsules have the potential to serve as fortified high calcium supplements.
In order to reduce the fire risk of rigid polyurethane foams (RPUF), three kinds of zeolitic imidazolate frameworks (ZIFs) were prepared. The results of Fourier transform infrared spectroscopy ...(FTIR), scanning electron microscope (SEM and X-ray diffraction (XRD) showed that ZIFs were successfully prepared. The combustion test results showed that the heat and smoke production of the composite containing ZIFs was obviously reduced. In particular, the peak heat release rate (PHRR) of ZIF-8/RPUF decreased from 740.85 kW/m
(Ref. RPUF) to 489.56 kW/m
, while the PHRR of ZIF-7/RPUF and ZIF-11/RPUF is 598.39 and 583.36 kW/m
, respectively. The addition of ZIFs improved the thermostability of the composite. The T50% of ZIF-8/RPUF, ZIF-7/RPUF and ZIF-11/RPUF increased to 364, 382 and 380 °C, respectively. The maximum light absorption of ZIF-7/RPUF and ZIF-11/RPUF was about 88%, which is higher than that of ZIF-8/RPUF (75%). The results of Raman spectroscopy showed that the I
/I
value of Ref. RPUF is 2.96, while the I
/I
value of ZIFs/RPUF reduces to less than 2.80. The main mechanism of ZIFs for reducing the fire risk of RPUF was the catalysis and incarbonization of ZIFs during combustion based on the results of thermogravimetric analysis and Raman spectroscopy of char residue.
Inflammatory bowel disease (IBD) is a kind of chronic inflammatory disease that is difficult to cure completely and may cause cancer. Modulating the intestinal flora is believed to be a feasible ...approach for IBD treatment. However, the traditional probiotics delivery systems often suffer from the inactivation caused by gastric acid. Herein, we proposed a novel probiotics-loaded microcapsule generated from a gas-assisted microfluidic platform. The microcapsules were composed of alginate shells and probiotics-containing cores, and exhibited good sphericity and biocompatibility, and had an average size of about 325 μm and a coefficient of variation of 2.57%. When the probiotics-loaded microcapsules were used for the IBD treatment of mice, they displayed good therapeutic effects in modulating oxidative stress and inflammation as well as protecting the intestinal barrier. These features indicate that the prepared probiotics-loaded microcapsules could be used as new materials for IBD treatment.
Graphical abstract
The gas-assisted microfluidic platform was employed to construct probiotics-containing microcapsules for inflammatory bowel disease treatment.
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•An effective film preparation method by sweep frequency pulsed ultrasound was developed.•Significant increases were observed in the mechanical properties of film by ...sonication.•Sonication achieved more a ordered and compact structure and a higher thermostability of film.•Ultrasonic treated film presented good antioxidant and antibacterial activities.
To produce a natural food packaging film from tuna skin collagen (TSC) and chitosan (CTS) and improve its mechanical and physicochemical properties, the sweep frequency pulsed ultrasound (SFPU) was introduced as a new technology and compared with the conventional method. The optimum preparation conditions of the SFPU-TSC-CTS film were sweep frequency of 28 ± 0.5 kHz, power density of 100 W/L, sweep frequency cycle of 100 ms, pulse duty ratio of 77%, and ultrasonic time of 10 min. Significant increases in the tensile strength (27.14%) and elongation at break (16.54%) and a significant decrease in the water vapor permeability (12.15%) were observed by sonication. Thus, a moderate SFPU treatment can significantly improve the moisture resistance and mechanical properties of the film. These enhancements were achieved by a more ordered and compact structure, a good crystallinity and a higher thermostability of SFPU-TSC-CTS film, which were verified by the Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal stability indexes. Moreover, SFPU-TSC-CTS film also presented good antioxidant and antibacterial activities. Therefore, SFPU was an effective auxiliary technology for improving the quality of food packaging film and can be deeply explored.
► High efficient ultrasound-assisted extraction method for antioxidant production. ► Antioxidant production from pomegranate marc with high yield. ► Environmentally friendly and energy saving pulsed ...ultrasound-assisted extraction.
There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from the dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25
±
2
°C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at an intensity level of 59.2
W/cm
2, and a pulse duration of 5
s and a resting interval of 5
s increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8
g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc.
► High efficient ultrasound-assisted extraction method for antioxidant production. ► Antioxidant production from pomegranate marc with high yield. ► Environmentally friendly and energy saving pulsed ...ultrasound-assisted extraction.
There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25
±
2
°C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at intensity level of 59.2
W/cm
2, and the 5 and 5
s of pulse duration and interval increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8
g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc.
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