Ethanol pre-treatment to ultrasound-assisted convective drying of apple

For the first time, the ethanol as pre-treatment to the ultrasound-assisted convective drying of food was evaluated. Pre-treatments were performed by immersion of apple slices in ethanol (0–30 min). Pre-treated samples were convectively dried (50 °C, 1 m s⁻¹), without/with ultrasound (21.77 kHz, 20.5 kW/m³). As results, if both technologies were considered, conventional drying time reduction reached 70 ± 2%. From drying kinetics modelling, it was identified that ethanol pre-treatments mainly reduced the external resistance to mass transfer, while ultrasound had a greater influence on the internal one. In dried samples, as the ethanol pre-treatment time increased, the shrinkage decreased, and their rehydration capacity was greater. After rehydration, samples showed a decrease of >85% in viscoelastic characteristics. The antioxidant capacity and total phenolic content were better retained with ultrasound application. The obtained results corroborate that the proposed technologies are complementary significantly accelerating the drying without negative effects on physical properties.     

Pulsed high-pressure processing of barley-based non-dairy alternative milk: β-carotene retention,protein solubility and antioxidant activity

Emerging technologies have been investigated as smart process options for manufacturing plant-based non-dairy alternative milk. However, few studies have evaluated the effects of these non-conventional technologies on the preservation of bioactive and nutritional compounds. In this regard, this study aimed to examine the impact of pulsed high-pressure processing at non-thermal and thermal conditions on the quality parameters of barley-based non-dairy milk enriched with β-carotene. The effects of the pressure (100, 300, and 600 MPa), number of pulses (1, 2, and 3 at 100 and 300 MPa), and temperature (40 and 80 °C) on the soluble protein content, β-carotene retention, total phenolic content, and flavonoid content were assessed. Also, we examined the antioxidant capacity of the samples using in vitro assays. The samples were exposed to pressure for 2 min, but the total treatment time varied from 2.5 to 9 min, according to the pressure and pulse conditions. Higher pressure pulses at 100 MPa favored the homogenization of the system. The solubility of the barley proteins increased by increasing the number of pulses from 1 to 3 at 100 MPa. β-Carotene was thermally degraded up to 20% by the thermal treatments at 80 °C. Additionally, the treatments performed at 80 °C provided samples with lower phenolic and flavonoid contents. On the other hand, the rise in pressure up to 300 MPa promoted the disruption of the cell membranes of barley particles, favoring the extraction of bonded phenolic and flavonoid compounds. Regardless of the number of pulses, samples treated at 300 MPa and 40 °C presented the highest phenolic and flavonoid contents. Antioxidant capacity results presented similar behavior as observed for phenolic and flavonoid contents. Therefore, the different combinations of pressure and temperature promoted distinct effects on the protein solubility and bioactive compounds of the barley-based non-dairy milk.     

Effects of combined high-pressure homogenization and enzymatic treatment on extraction yield,hydrolysis and function properties of peanut proteins

Peanut protein isolate (PPI) was extracted by high-pressure homogenization (HPH) under 0.1 MPa (atmospheric pressure) and 40 or 80 MPa (high pressure). Effects of Alcalase (a proteolytic enzyme) on the enzymatic hydrolysis of PPI and the antioxidant activity of the PPI hydrolysates were investigated. The molecular weight distributions of the PPI hydrolysates were analyzed using Sephadex G-25 gel filtration chromatography while the antioxidant activities, including reducing power, 1,1-dipheny-2-picrylhydrazyl (DPPH) radical-scavenging activity and hydroxyl free radical-scavenging activity of the PPI hydrolysates were evaluated. The extraction yields of PPI by HPH under 0.1, 40 and 80 MPa were 16.84, 30.65 and 39.86%, respectively, which showed that HPH treatment improved the PPI extraction. The HPH treatment increased the degree of hydrolysis of PPI and significantly increased the reducing power and hydroxyl radical­scavenging activity. Furthermore, the molecular weight distributions of the PPI hydrolysates appeared principally over the range of 1000–5000 Da, while the HPH treatment enhanced the production of small peptides, which was in agreement with the high PPI hydrolysis degree. These results suggest that HPH treatment in combination with enzymatic hydrolysis could modify PPI properties and increase the antioxidant activities of the PPI hydrolysates.Industrial relevanceThis study was focused to evaluate the effects of high-pressure homogenization (HPH) in combination with enzymatic hydrolysis on extraction yield and enzymatic hydrolysis of PPI and antioxidant activity of the PPI hydrolysates. This study indicated the possibility of improving the availability of PPI by HPH treatment via increasing extraction yield and enzymatic hydrolysis of the PPI, which can provide a better utilization of the peanut by-product.     

Potential of high pressure homogenization to solubilize chicken breast myofibrillar proteins in water

Myofibrillar proteins (MPs) of chicken breast were generally insoluble in water. The potential of high-pressure homogenization (HPH) to solubilize chicken breast MPs in water was tested. The effects of 0 psi (0.1 MPa), 10,000 psi (69 MPa), 15,000 psi (103 MPa) and 20,000 psi (138 MPa) for two passes HPH on solubility, protein profile, particle property, flow property and microstructure of MPs in water were investigated. HPH at 15,000 psi (103 MPa) could induce the suspension of MPs with small particle size species (sub-filament, oligomers or monomer structure) and high absolute zeta potential, thus enhancing the solubility, flow ability and stability without individual protein degradation. Reduction of particle size and strengthening of intermolecular electrostatic repulsion appeared to be the main reasons in solubilizing MPs in water treated with HPH.Industrial relevanceThe qualitative characteristics of meat products are closely related to the solubility of meat proteins. Myofibrillar proteins (MPs), as major part of total muscle proteins, are generally considered to be insoluble in water. The results showed that high-pressure homogenization has potential application for solubilizing MPs in water to develop new meat-based products in the food industry.     

Development of bioactive edible film from turmeric dye solvent extraction residue

We developed and characterized turmeric flour films using the turmeric dye solvent extraction residue. We evaluated how the heating temperature and pH affected film properties using a 2² central composite design. Multi-response analysis furnished the film formulation that offered larger resistance to break, as well as lower water solubility, WVP, and opacity. The heating temperature and pH affected the mechanical properties, solubility, moisture content, WVP, and opacity of the resulting film. High heating temperature promoted more interactions between the polymers present in the turmeric flour (starch, protein, lipid, and fiber), affording a more resistant polymeric structure with lower WVP, moisture content, and opacity. Higher pH values also favored a more mechanically resistant and dense matrix with lower water solubility and WVP. The optimized conditions were: T = 86.7 °C and pH = 8.5. The films produced under these conditions displayed high mechanical strength (18 MPa), low solubility (36%), and low WVP (0.167 g mm h⁻¹ m⁻² kPa⁻¹). However, because these films contained lignocellulosic fibers, they presented low elongation at break (1.8%), which elicited a non-continuous structure. HPLC and DPPH assays showed that the turmeric dye solvent extraction residue can be a promising source to develop films with antioxidant activity.     

Casein peptides with inhibitory activity on lipid oxidation in beef homogenates and mechanically deboned poultry meat

Bioactive peptides obtained by enzymatic hydrolysis of casein may have antioxidant activity. In this work, casein peptides were obtained using the proteolytic enzymes Alcalase and Flavourzyme. Casein was hydrolyzed for 4 h at 50 °C and pH 8, and the resulting peptides were analyzed. The enzymatic hydrolysis with Flavourzyme resulted in higher concentration of soluble protein and free amino acids, and produced peptides with lower molecular mass than those obtained with Alcalase, as observed by gel permeation chromatography and polyacrylamide gel electrophoresis. Casein peptides obtained with Flavourzyme also exhibited greater antioxidant capacity using the ABTS radical method. Casein peptides (20 mg ml⁻¹) effectively inhibited lipid peroxidation in ground beef homogenates and mechanically deboned poultry meat. Casein peptides may be useful in meat processing as another naturally occurring antioxidant, helping to prevent off-flavor formation in meat products and increasing shelf life.     

Effect of high pressure treatment on the physicochemical and functional properties of egg yolk

The effects of high-pressure (HP) treatment at 100–500 MPa on some physicochemical and functional properties of egg yolk (EY) were investigated. Protein solubility, viscosity, surface hydrophobicity (H₀), free sulfhydryl (SH) content, differential scanning calorimetry characteristics, emulsifying activities and emulsifying stability were evaluated. HP-treatment resulted in protein aggregation, as evidenced by gradual decrease in protein solubility and significantly increased in viscosity. HP-treatment at 100–500 MPa induced a gradual decrease in H₀ and SH content, possibly due to protein unfolding and subsequent aggregation/re-association of unfolded proteins. Emulsifying activity index (EAI) was slightly decreased between 100 and 300 MPa and when the pressure is above 400 MPa, EAI was significantly (P < 0.05) decreased relative to the untreated EY. HP-treatment at 100 MPa significantly (P < 0.05) increased the ESI values of EY, while a significant (P < 0.05) decrease was observed when the pressure was above 200 MPa. It was also investigated that there are significant correlations between physicochemical properties of EY, and the differences in the modification of EY protein by HP treatment at different pressure levels may be attributed to the differences in aggregation and unfolding/refolding extents of proteins.     

Cricket protein hydrolysates pre-processed with ultrasonication and microwave improved storage stability of goat meat emulsion

The study was designed to evaluate the potential of cricket protein hydrolysates as a novel food bio-preservative using goat meat emulsion as a food-model system. The efficacy of the hydrolysates was improved using microwave (T₁) and ultrasonication (T₂) as pre-treatments before hydrolysis of cricket protein using alcalase enzyme (3% w/w). Both the pre-treatments caused a significant increase in the antioxidant and antimicrobial potential of the hydrolysates. The hydrolysates were added to the emulsion at the maximum level of 2.0% and analysed for quality for two weeks storage (4 ± 1 °C) compared to the control samples. The effect of digestion simulation was also evaluated on the emulsion samples. A significant positive effect of the pre-treated hydrolysates was observed on the storage stability (antioxidant potential, lipid stability, protein oxidation, microbial stability, and sensory quality). The digestion simulation significantly increased the radical-scavenging and ion-reducing activity of the meat emulsion, improving its functional value and health-promoting properties.     

Microwave and pulsed electric field assisted extractions of polyphenols from defatted canola seed cake

The incorporation of microwave and pulsed electric field (PEF) technologies in optimising the extraction of polyphenols from defatted canola seed cake was determined by Box‐Behnken response surface methodology, using three parameters of microwave treatment (power, time and liquid: solid (L:S) ratio) and four parameters of PEF (ethanol concentration, time, frequency and voltage). After microwave and PEF pretreatments, the polyphenols of defatted canola seed cake were extracted by ultrasound treatment under fixed variables (200 W of ultrasonic power, 70 °C of water bath and 20 min of extraction time). The measured responses were total phenolics, total flavonoids, the DPPH˙ scavenging activity and ferric reducing antioxidant power (FRAP). The maximum yields of all responses were achieved under optimum conditions of microwave processing (5 min, L:S ratio of 6.0 and 633.3 W) and PEF‐assisted extraction (30 V, 30 Hz, 10% ethanol concentration and 10 s).     

Functional properties and in vitro trypsin digestibility of red kidney bean (Phaseolus vulgaris L.) protein isolate: Effect of high-pressure treatment

The effects of high-pressure (HP) treatment at 200–600 MPa, prior to freeze-drying, on some functional properties and in vitro trypsin digestibility of vicilin-rich red kidney bean (Phaseolus vulgaris L.) protein isolate (KPI) were investigated. Surface hydrophobicity and free sulfhydryl (SH) and disulfide bond (SS) contents were also evaluated. HP treatment resulted in gradual unfolding of protein structure, as evidenced by gradual increases in fluorescence strength and SS formation from SH groups, and decrease in denaturation enthalpy change. The protein solubility of KPI was significantly improved at pressures of 400 MPa or higher, possibly due to formation of soluble aggregate from insoluble precipitate. HP treatment at 200 and 400 MPa significantly increased emulsifying activity index (EAI) and emulsion stability index (ESI); however, EAI was significantly decreased at 600 MPa (relative to untreated KPI). The thermal stability of the vicilin component was not affected by HP treatment. Additionally, in vitro trypsin digestibility of KPI was decreased only at a pressure above 200 MPa and for long incubation time (e.g., 120 min). The data suggest that some physiochemical and functional properties of vicilin-rich kidney proteins can be improved by means of high-pressure treatment.     

Effect of high-pressure treatment on the quality of prepared chicken breast

In this study, the effect of high-pressure processing (HPP) on the physico-chemical properties and microstructure of prepared chicken breast meat products was investigated. The result showed that the pH and TBARS values of the prepared chicken breast gradually increased, while the total volatile basic nitrogen value constantly decreased with the increase of pressure (0.1–500 MPa). In addition, the colour attributes (L* and a* values) and texture indexes (hardness and chewiness) significantly improved as the pressure increased. The results of low-field nuclear magnetic resonance demonstrated that the peak area of immobilised water (T₂₂) first enhanced and then declined with the increase of pressure, reaching the maximum value at 200 MPa. Moreover, the integrity of microstructure and protein secondary structure of prepared chicken breast were also disrupted. These findings could serve as a theoretical basis for a better application of HPP in prepared chicken breast meat products.     

High pressure pre-treatment of Moringa oleifera seed kernels prior to aqueous enzymatic oil extraction

High pressure processing (HPP) was applied as a pre-treatment on Moringa oleifera (MO) kernels, for the first time, prior to aqueous enzymatic extraction (AEE) of the MO oil, and the effect of this pre-treatment is reported in terms of the free oil recovery and the nature of the cream emulsions formed. The HPP pre-treatments (50–250 MPa, 20–60 °C, 10–60 min) generally resulted in higher free oil recoveries and thinner emulsion layers from ground-sieved kernels than the whole kernels. Optimization of the HPP parameters indicated linear increment in free oil recovery with increase in temperature and time, but not the pressure level. Without the pre-boiling step in the AEE process, the use of HPP pre-treatment at 50 MPa and 60 °C for 35 min resulted in approximately 73% (w/w) free oil recovery with thinner emulsion layer than the use of AEE alone. These findings highlighted the ability of HPP in altering the MO protein structure into a form of less emulsifying functional properties, thus further de-emulsification method may not be necessary.Industrial relevanceHigh pressure processing (HPP) applications are increasing in the food industry. High pressure application allows the use of relatively lower temperatures in processes, in order to achieve comparable outcomes of higher temperature processing. This study explores the application of HPP on Moringa oleifera (MO) kernels prior to aqueous enzymatic extraction (AEE) of oil. In general, the main disadvantage of AEE is its lower oil recovery in comparison with solvent extraction, which is attributed to the formation of a relatively stable cream emulsion after extraction. This study shows that the thickness of the creamy emulsion can be significantly reduced, and oil recoveries improved, by subjecting the kernels to HPP prior to extraction. The improvement in recoveries did not depend strongly on the level of high pressure applied, but downstream processes for free oil separation and recovery were considerably simplified.     

Extraction of proteins from slaughterhouse by-products: Influence of operating conditions on functional properties

This study investigated the extraction and functional properties of proteins from slaughterhouse by-products: pork lungs, beef lungs and mechanically deboned chicken meat (MDCM). The extraction yield was investigated as a function of pH, temperature and time. Membrane technology was used for purification of proteins from pork and beef lungs, while for MDCM a method based on PI was applied. In the three cases, yields of protein recovery were between 48 and 55% (w/w). The functional properties of the protein concentrates were compared to those of some commercial ingredients. Proteins from pork lungs and MDCM exhibited better gelling properties than egg white and beef plasma, while beef and pork lungs displayed very good emulsifying properties, similar to Na-caseinates. As the methods developed are easy to scale-up, the use of by-product proteins at industrial scale appears to be an interesting opportunity to obtain added value slaughterhouse by-products.     

前处理对鸡汤体系营养特性的影响

采用醋浸、预炒及复合3 种前处理方式制作鸡汤,研究前处理方式对烹制前后鸡汤体系营养成分及蛋白质消化特性的影响,为鸡汤制品的工业化生产提供参数。结果表明,前处理可使生肉的水溶性蛋白显著增加,熟肉的水溶性糖有所增加。预炒处理可提高熟肉的蛋白质消化率,游离氨基酸、粗脂肪、灰分含量,提高汤汁中游离氨基酸、粗脂肪含量,促进汤汁中可溶性固形物的溶出。醋浸可提高汤汁的游离氨基酸含量和熟肉的蛋白质消化率。比较而言,预炒是一种较好的前处理方式。     

Impact of high-pressure homogenization pretreatment on recovery of curcumin from turmeric by different combinations of extraction and drying methods

This study reports the effect of different extraction and drying techniques in the recovery of curcumin, where the impact of the pre-treatment step on turmeric rhizome using high-pressure homogenization (HPH) was evaluated. Soxhlet extraction (SE) and ultrasound-assisted extraction (UAE) followed by drying (oven drying, vacuum drying, and freeze drying) were applied to HPH-treated and control (non-HPH) samples. The HPH treatment condition of 100 MPa for 10 cycles demonstrated the lowest particle sizes in the turmeric suspensions and the highest curcumin content in the aqueous supernatant. It was also found that HPH treatment increased the release of curcumin from the freeze-dried turmeric extracts obtained from SE (+76.2%) and UAE (+57.5%). Besides, freeze drying was the best drying method demonstrating higher antioxidant activity of extracts than other thermal drying methods. The total phenolic content was increased by about 65.5% upon HPH treatment on turmeric extract obtained from UAE followed by vacuum drying.     

Functional properties of whey proteins as affected by dynamic high-pressure treatment

An ultra high-pressure homogenizer was used to treat whey protein isolate solutions (3%, w/w). The treated solutions (up to 300 MPa) were characterised for both physico-chemical properties (particle size distribution, surface hydrophobicity and structural conformation) and functional properties (solubility, foaming stability and interfacial rheology). Dynamic high-pressure treatment did not affect the conformation of the proteins (determined by micro-calorimetry, size-exclusion chromatography and electrophoretic technique). This treatment dissociated large protein aggregates leading to unmasking of the buried hydrophobic groups without affecting protein solubility. Interactions may then occur between these groups that enhance the viscoelasticity of air-water interfaces (assessed by drop tensiometry) and improve foam stability (evaluated by sparging method). Dynamic high-pressure-treated whey proteins showed better foaming and stabilising properties.     

The effect of Pulsed Electric Field as a pre-treatment step in Ultrasound Assisted Extraction of phenolic compounds from fresh rosemary and thyme by-products

Emerging extraction techniques, including pulsed electric field (PEF) and ultrasound (US), are attracting considerable interest in the recovery of bioactives. Though, limited work has focused on PEF application as pre-treatment for US assisted extraction to enhance the release of phenolics from herbs. Hence, the present study investigated the use of an optimized PEF pre-treatment to enhance the recovery of phenolics from fresh rosemary and thyme by-products in a subsequent US assisted extraction step. Total phenolic content (TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) were assessed as an index of extraction efficacy. Qualitative and quantitative analyses were performed through liquid chromatography-mass spectrometry analyses to evaluate the influence of the methods on individual phenolic compounds and the formation of potential derivatives. The results indicated that in a number of cases PEF pre-treatment enhanced (p < 0.05) the recovery of phenolic compounds and antioxidant capacity compared to US individually.     

Functional and Biochemical Changes in Deboned Turkey due to Frozen Storage and Lipid Oxidation

The effect of frozen storage and lipid oxidation on protein functional and biochemical properties of mechanically deboned and hand deboned turkey meat was investigated. Turkey meat was evaluated by the 2-thiobarbituric acid test and cook yield. Isolated turkey myofibrils were analyzed for solubility, ATPase activity, gel strength, and gel microstructure. Frozen storage caused protein insolubilization and changes in the biochemical and functional properties in all treatments. Antioxidants prevented some of the biochemical and functional changes in the meat. Myofibril gel microstructure changed from a continuous filamentous matrix to a globular matrix with decreased waterholding capacity during frozen storage of the turkey meat.     

Identification of antioxidant peptides derived from egg-white protein and its protective effects on H2O2-induced cell damage

To identify novel antioxidant peptides from egg-white protein and investigate antioxidant mechanism, the hydrolysate of egg-white protein was purified by ultrafiltration and a Sephadex G-15 column. The peptides VYLPR, EVYLPR, VEVYLPR and VVEVYLPR were identified from the fraction with the highest antioxidant activity. The Results showed that the peptide VYLPR exhibited the strongest protective effect on HEK-293 cells. The viability of cells recovered to 97.45 ± 1.98% with pre-treatment of 20 μm VYLPR. We further investigated antioxidant mechanism. The results showed VYLPR could inhibit lipid peroxidation process, maintain cell membrane integrity, inhibit intracellular LDH activity, reduce MDA content, and improve the activity of antioxidant enzyme T-SOD and GSH-Px. This work could help researchers in understanding antioxidant mechanism of peptides and also contribute to developing functional egg-white product.     

Microwave and ultrasound assisted extraction of phytocompounds from black jamun pulp: Kinetic and thermodynamics characteristics

The present study focuses on the extraction of phenolic compounds, anthocyanin and antioxidants from black jamun pulp by microwave and ultrasound assisted extraction process. The microwave-assisted extraction was carried out for 240 s at microwave power level of 100–400 W. The yield of total anthocyanin and total phenolic content in the microwave assisted extraction process at 400 W power level after an extraction period of 240 s was 8.197 mg of C3G g⁻¹ and 37.671 40.632 mg GAE g⁻¹, respectively. The ultrasound assisted extraction was performed at temperatures of 40, 50, 60, and 70 °C for 150 min. In the ultrasound assisted extraction at a sonication temperature of 70 °C, the yield of anthocyanin was 8.525 mg of C3G g⁻¹, while the yield of the phenolic compound was 47.331 mg GAE g⁻¹. The pseudo-second order model was found to be the most suitable model to represent the extraction kinetics of anthocyanin, phenolic compounds, and antioxidant activity of black jamun pulp. The effective diffusion coefficient for ultrasound assisted extraction of phenolic components, anthocyanin, and antioxidant activity in the temperature range of 40-70 °C was 5.704× 10⁻¹²–10.515 10⁻¹², 2.485× 10⁻¹² -8.507× 10⁻¹², and 2.061× 10⁻¹²–11.977 × 10⁻¹² m².s⁻¹ respectively. The negative Gibbs free energy change values for extraction of phenolic compounds and anthocyanin specified that the reaction was feasible and spontaneous. Thermodynamic parameters such as positive enthalpy change and positive entropy change indicated that the ultrasound assisted extraction process was endothermic and irreversible in nature.