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Ultrason Sonochem
Ultrason Sonochem
Ultrasonics Sonochemistry
1350-4177
1873-2828
Elsevier

S1350-4177(24)00290-6
10.1016/j.ultsonch.2024.107042
107042
Original Research Article
Combined pulsed electric field-ultrasound assisted extraction of yarrow phenolic-rich ingredients and their nanoliposomal encapsulation for improving the oxidative stability of sesame oil
Razghandi Elaheh a
Elhami-Rad Amir-Hossein a
Jafari Seid Mahdi smjafari@gau.ac.ir
bc⁎
Saiedi-Asl Mohammad-Reza a
Bakhshabadi Hamid d
a Department of Food Science and Technology, Sabzevar Branch, Islamic Azad University, Sabzevar, Iran
b Department of Food Materials and Process Design Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
c Halal Research Center of IRI, Iran Food and Drug Administration, Ministry of Health and Medical Education, Tehran, Iran
d Department of Agriculture, Minab Higher Education Center, University of Hormozgan, Bandar Abbas, Iran
⁎ Corresponding author at: Department of Food Materials and Process Design Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. smjafari@gau.ac.ir
22 8 2024
11 2024
22 8 2024
110 1070426 7 2024
20 8 2024
21 8 2024
© 2024 The Author(s)
2024
https://creativecommons.org/licenses/by-nc/4.0/ This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).
In this research, yarrow phenolic-rich extract was produced using pulsed electric field (PEF)-ultrasound assisted technology. The highest extraction efficiency (5.99 %) was obtained at 6.25 kV/cm of PEF and the sonication time of 60 min. As the PEF intensity and sonication time rose, the total phenolic content (TPC) and ferric-reducing power (RP) of the extracts increased. The PEF intensity of 2.70 kV/cm and sonication time of 45.83 min were the optimum extraction conditions resulting in the highest extraction efficiency, TPC, and RP. Then, this optimum extract was loaded into nanoliposomes. At higher extract levels, the encapsulation efficiency lowered, while the particle size, polydispersity index (PDI), and zeta potential of the nanoliposomal samples elevated. The results of Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) confirmed the successful encapsulation of yarrow extract into nanoliposomal carriers; the sample containing the extract had the highest enthalpy (3600 J/g) and nanoliposomes loaded with yarrow antioxidant extract (0.11 mL/mg) was the optimum sample. Finally, the sesame oil containing 500 ppm free and nanoliposome extract, as well as the sample with 200 ppm BHT were evaluated for oxidative stability. The highest oxidation stability (14.21 h) belonged to the oil containing nanoliposomal yarrow phenolic extract.

Keywords

Natural antioxidants
Pulsed electric field
Sonication
Nanocarriers
Oxidation
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pmc1 Introduction

The edible oil oxidation shortens the shelf-life of food products, resulting in their unacceptable quality for consumption. There are several methods for oxidation prevention, one of which is the application of natural antioxidants which can delay off-flavor and rancidity by extending the stability time. These antioxidants have various mechanisms including controlling the oxidation of substrates and proxidants, as well as inactivating the free radicals [1]. On the other hand, utilization of synthetic antioxidants such as butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tert-butylhydroquinone (TBHQ) in food products has been limited, due to their detrimental effects on human health. Therefore, attempts have been made in recent years to find new sources of natural antioxidants [2], [3]. Phenolic compounds found in herbal by-products constitute the most important group of natural antioxidants. Numerous studies have shown that they are proper antioxidants against the peroxidation of fats and phospholipids in biological systems [4]. Yarrow, Achillea millefolium L., is a plant native to Iran, which comprises different substances including tannins, choline, acetylcholine, flavonoids, valeric acid, amino acids, fatty acids, sterols, thiamin, ascorbic acid and calcium [5]. Yarrow has oxytocic, anti-inflammatory, and anti-ulcer activities [6]. The methanolic extract of this flower and its leaf has antibacterial properties [7]. Flavonoids, piperitone, cineol, limonene, p-cimin, and champhor are the major constituents of yarrow essential oil, which have high antioxidant activities [8], [9].

There are many methods for extracting bioactive compounds from herbal sources, each having advantages and disadvantages considering the extraction process [10]. Conventional extraction techniques like maceration and Soxhlet process are often time-consuming with low efficiency, leading to a rise in production costs. Moreover, the organic solvents such as ethanol, methanol, hexane, and acetone used in such methods, have undesirable effects on the environment, and since the residues of such solvents in the final product cause various disorders and diseases in the consumer body, novel extraction methods have drawn considerable attention [11]. Ultrasound is a category of waves with frequencies > 18–20 kHz. Owing to its higher efficiency and lower energy consumption, ultrasound-assisted extraction (UAE) is emerging as an appropriate alternative to conventional extraction techniques. It is an enhanced method of processing herbal compounds, especially extracting low-molecular-weight substances [12]. The effect of UAE on the extraction rate of herbal components is associated with the breakdown of the cells and the diffusion of their contents into the extraction medium [13]. Oroian, et al. [14], Dzah, et al. [15], Quiroz-Reyes and Aguilar-Méndez [16], and Sirichan, et al. [17], the researchers who have studied UAE of herbal nutraceuticals. Pulsed electric field (PEF) technology is defined as the discharge of high-voltage short electric pulses into the foods placed between two electrodes [18]. It influences diffusivity and increases the extraction efficiency (EXE) of plant ingredients [19]. As a result, the potential of PEF for raising EXE of different substances from plant tissues has been studied by various researchers, e.g., Bakhshabadi, et al. [20], and Hosseini, et al. [21].

Encapsulation is the technology of entrapping solid, liquid, or gaseous materials in capsules which release their contents at controlled rates under particular conditions. This process includes the formation of a wall around the bioactive compounds, ensuring that they do not diffuse out of the capsule and the unfavorable compounds are not entrapped [22]. Liposomes are a group of lipid carriers employed for the encapsulation of bioactive compounds. They are colloidal vesicles composed of polar lipids, particularly phospholipids, which develop spherical bilayer structures in the presence of water molecules. Because of being amphiphilic, liposomes can load a variety of hydrophilic, lipophilic, and amphiphilic substances [23]. Although liposomes and nanoliposomes have the same structural, chemical, and thermodynamic properties, nanoliposomes provide a larger surface area due to their smaller sizes, leading to the improved solubility, bioavailability, controlled release and more precise delivery of the encapsulated compounds to the target area. Additionally, nanoliposomes are more stable and create less turbidity [24]. Raw lecithin consists of phospholipids (phosphatidylcholine, phosphatidyl-ethanolamine, and phosphatidylinositol), neutral lipids, and carbohydrates. Theoretically, lecithin consumption elevates the level of polyunsaturated fatty acids in the body, contributes to lipid absorption and enhances the function of lymphatic cells [25]. In conclusion, the present study aimed to apply the PEF-ultrasound pretreatment to improve the EXE of yarrow natural antioxidants, as well as the encapsulation of the resulting extract using nanoliposomes.

2 Materials and methods

Yarrow was purchased from a local market (Sabzevar, Iran). Edible lecithin and sesame oil were provided by cotton and oilseeds Co., Iran. Folin-Ciocalteu reagent, sodium carbonate, sodium phosphate buffer, trichloro acetic acid, and gallic acid were supplied from Merck Co., Germany, and Sigma-Aldrich Co., the USA.

2.1 Sample preparation and extraction

The aerial parts of the yarrow plant were separated, shade-dried, and ground to produce powder; 20 g of the powder was subjected to PEF treatment at 0.25, 3.25, and 6.25 kV/cm with 50 pulses. A batch PEF system was designed and constructed at the Research Institute of Food Science and Technology, Iran, which had a 1 kg capacity. In the PEF chamber, the powder of the samples was mixed with water (140 mL). Subsequently, the samples were sonicated in an ultrasonic bath (Agilent, USA) operating at a frequency of 50 kHz, with an intensity of 75 %, a power of 150 W, and a capacity of 40 L (stainless steel) at 20 °C for 20, 40, and 60 min, with temperature control throughout the process.

The resulting extract was immediately filtered and powdered using a rotary evaporator (Buchi, Switzerland). The control extract was prepared using water as a solvent for 24 h without being subjected to the PEF-ultrasound pretreatment. In all the extracts, the sample:solvent (water) ratio was 1:10 [20], [26]. The extraction schematic is shown in Fig. 1.Fig. 1 Schematic of the extraction system in this study.

2.2 Extraction efficiency and total phenol content (TPC) measurement

The 10 mL (m1) of the extract was poured onto a clean dry plate and weighed. The plate was then heated in a hot-air oven (Memmert, Germany) at 80 °C until it reached a constant weight (m2). EXE was calculated by Eq. (1) [21]:(1) Extractionefficiency=m2m1×10

The method presented by Hosseini, et al. [21] was applied to determine the TPC of the extracts. A constant volume of the extract was poured into a test tube. Next, the 10-fold diluted Folin-Ciocalteu reagent was added to the tube. After 10 min, distilled water and 2 mL sodium carbonate 7.5 % (w/v) was added. Finally, the resulting mixture was kept at room temperature for 30 min. Afterward, the absorbance value of the mixture was measured at 765 nm in 1-cm cells using a spectrophotometer (Biochrom, the UK). The standard curve was drawn using gallic acid (10–200 ppm). The TPC of the extracts was expressed as mg gallic acid per 100 g sample dry matter.

2.3 Determination of ferric-reducing antioxidant potential (FRAP)

The FRAP of the samples was assessed according to the reduction of potassium ferric cyanide and the color change from yellow to green or blue. So, 0.03 g of the sample was combined with 2.5 mL sodium phosphate buffer (pH=6.6) and 2.5 mL potassium ferric cyanide (1 %). The mixture was kept in a water bath at 20 °C for 50 min. Subsequently, 2.5 mL trichloro acetic acid (10 %)was added, and the mixture was centrifuged (Thermo, Japan) at 1350 g and ambient temperature for 50 min. Afterward, 2.5 mL of the supernatant was blended with 2.5 mL distilled water and 0.2 mL ferric chloride (0.1 %). Eventually, the absorbance value of the mixture was read at 700 nm using a spectrophotometer (Biochrom, the UK). An increase in the absorbance value indicates a rise in the FRAP of the sample [27].

2.4 Scanning electron microscopy (SEM)

SEM was used to evaluate the microstructure of samples. After ensuring the dryness, samples were stuck onto the aluminum base using silica glue. The bases were then coated using a sputter coater. Finally, the images were captured at a magnification of 1000X [28].

2.5 Preparation of nanoliposomes

Various lecithin:extract ratios (5, 6, 7, 8, and 9-fold) were used to prepare the nanoliposomes. In other words, the concentrations of extracts incorporated into nanoliposomes were 0, 0.11, 0.125, 0.143, 0.167, and 0.2 mL/mg lecithin. First, the antioxidant extract powder was dissolved in water: ethanol (30:70) mixture. Next, soy lecithin was added, and the mixture was vacuum-dried using a rotary evaporator. Subsequently, the thin formed layer was hydrated with 10 mL sterile distilled water, and the glass dunks were added to help the hydration of the thin lipid layer. In this step, multilayer liposomes were produced on a microscale [29]. Then, the sample was homogenized at 12000 rpm for 10 min at a temperature higher than the liposomes‘ phase transition temperature. Finally, the liposomal mixture was sonicated using a probe ultrasound system (Hielscher, Germany) inside an ice bath to prevent lipid hydrolysis and oxidation. Nine 20-s cycles were exerted on the sample with 30 s of rest between the cycles. Single-layer nanoliposomes were produced in this step, which were then freeze-dried (Christ α 1–4, Germany) for 48 h.

2.6 Characterization of extract-loaded nanoliposomes

To determine the encapsulation efficiency (ENE) of the extracts, 2 mL of the freshly prepared sample was poured into a 100-kDaAmicon filter and centrifuged at 3000 g for 10 min [30]. The TPC of the filtrate was measured according to Section 2.2. Ultimately, ENE of the phenolic compounds was obtained from Eq. (2):(2) Encapsulationefficiency(%)=E-DE×100

where E and D represent the TPC of the initial extract and the filtrate, respectively.

Dynamic light scattering (DLS) was employed to measure the size of the nanoliposomes 30 min after production. This technique operates based on laser light diffraction [31]. In this test, the refractive index, dielectric constant, and temperature were equal to 1.33, 78.5, and 25 °C, respectively, and the measurements were done at a scattering angle of 173 °C. The surface electrical charge of particles, referred to as zeta potential, is a reliable index for predicting the dispersion stability of colloids during storage. This feature was determined using a Zetasizer (Malvern, the UK) which operates based on the electrophoretic displacement of the surface charge [30], [31].

To quantify the thermal properties of the samples, 5 ± 0.01 mg of each sample was filled in the aluminum pan of the DSC apparatus (PerkinElmer, the USA), which was further sealed. The glass transition temperature (Tg), melting point (Tm), and denaturation enthalpy (ΔHd) of the samples were measured. First, the device was calibrated using indium (Tm,onset = 156.6 °C, ΔH=28.45 J/g). A pan containing water with the same mass as the sample was used as a blank. The sample was heated from 50 to 300 °C at 30 °C/min, and the enthalpy was quantified by calculating the area under the curve using STARe system software [32]. The interactions between the extract phenolics and the lipid membranes were evaluated through Fourier transform infrared (FTIR) spectroscopy. The wavenumber of the device (Shimadzu, Japan) was set at 4000–400 cm−1. A mass of the sample was mixed with potassium bromide at a ratio of 1:100 and subjected to the FTIR analysis [33]. Similar to the initial samples (Section 2.4), SEM was utilized to study the microstructure of the prepared nanoliposomes and to ensure the encapsulation of the extracts within them [34].

2.7 Preparation of sesame oils containing yarrow extract nanoliposome

After preparing nanoliposomes containing yarrow plant extract, (500 ppm) were prepared and added directly to sesame oil without antioxidants. It should be noted that in this section, a sample containing 200 ppm BHT antioxidant and a sample containing free Yarrow plant extract (500 ppm) were also evaluated [35].

2.8 Determination of oxidative stability

To determine the stability of oils against oxidation, Ransimat (Metrohm, Switzerland) and AOCS Cd 12b-92 (1993) methods were used, at 110 °C and an inlet air flow rate of 20 L/h.

2.9 Statistical analyses

In the first step of this research (antioxidants extraction), a rotatable central composite design (CCD) was employed to investigate the relationship between the independent and dependent variables. Using Response surface methodology (RSM), all the regression coefficients, including the linear, second-order, and interaction ones, were estimated. Our purpose was to optimize the extraction process of yarrow antioxidants by the PEF-ultrasound pretreatment. To that end, the quadratic model was fitted to the obtained data for each response. The adequacy of the model was verified by the lack of fit and determination coefficient. All the analyses were carried out using Design Expert version 12. In the second step (encapsulation into nanoliposomes), a full-factorial completely randomized design and Duncan‘s multiple-range test were used to compare the optimum and control (untreated) samples. All the analyses were performed using the SAS 9.4 version.

3 Results and discussion

3.1 Extraction efficiency of yarrow phenolic-rich compounds

Table 1 shows that the quadratic model best fitted the data of EXE (P=0.0003). Moreover, analysis of variance (ANOVA) revealed that all the linear and quadratic effects of the model were significant, while the interaction between the EF intensity and sonication time did not have a significant effect on the response at P<0.05 (Table 2). The results indicated that Exe was raised as the EF intensity and sonication time increased, and the highest EXE (5.99 %) was acquired at the EF intensity = 6.25 kV/cm and the sonication time = 60 min (Fig. 2). This could be attributed to the electrical dissociation and higher permeability of cells [36]. Shorstkii, et al. [37], Bakhshabadi et al. [20], and Hosseini, et al. [21] also demonstrated that the application of PEF led to the breakdown of the seed's initial structure and consequently, a rise in EXE. Ultrasonication results in the collapse and explosion of cavitation bubbles. With a rise in sonication time, cavitation bubbles are created, whose collapse energy causes the destruction of cell walls and a higher mass transfer rate from the plant tissue to the solvent [26]. The SEM graphs (Fig. 3) also proved that the use of this pretreatment created some holes on the surface of the yarrow tissue, thus elevating EXE. Quiroz-Reyes and Aguilar-Méndez [16] declared that an increase in the PEF-ultrasound time gave rise to the EXE of cocoa compounds. Similarly, Sirichan, et al. [17] claimed that EXE of orange major components rose as the sonication time increased, conforming to the findings of the present research. Considering the model terms (Table 3), it can be concluded that the linear term of the sonication time had the most profound effect on EXE.Table 1 Model selection for dependent variables (responses).

	Extraction efficiency	Total phenolic content	Ferric reducing antioxidant potential	
Models	SS	P-value	SS	P-value	SS	P-value	
Mean	297.12	−	43092.87	−	0.83	−	
Linear	10.08	< 0.0001	206.67	0.36	0.0054	0.53	
2FI	0.04	0.66	156.88	0.21	0.01	0.12	
Quadratic	1.56	0.0003	623.89	0.0024	0.023	0.003	
Cubic	0.11	0.09	20.43	0.66	0.002	0.362	
Residual	0.06	−	114.61	−	0.004	−	
Total	308.97	−	44215.35	−	0.873	−	
SS: Sum of squares and P-value: Probability value.

Table 2 Analysis of variance for dependent variables.

Source	Extraction efficiency	Total phenolic content	Ferric reducing antioxidant potential	
	SS	F-Value	P-value	SS	F-Value	P-value	SS	F-Value	P-value	
Model	11.68	96.26	0.0003	987.43	10.24	0.004	0.039	8.96	0.006	
X1	4.33	178.66	< 0.0001	205.92	10.67	0.0137	0.005	6.20	0.042	
X2	5.74	236.68	< 0.0001	0.75	0.04	0.849	0.00	0.019	0.894	
X12	0.22	1.65	0.018	156.88	8.97	0.020	0.01	11.49	0.019	
X22	0.78	9.41	0.0007	172.98	11.08	0.013	0.008	9.22	0.028	
X1X2	0.04	32.29	0.24	213.83	8.13	0.025	0.007	7.58	0.011	
Residual	0.17			135.04			0.006			
Lack of fit	0.17	3.96	0.06	133.97	6.12	0.10	0.006	9.20	0.13	
Pure Error	0.0005			1.08		−	0.0002			
Total	11.85			1122.47		−	0.045			
X1: Electric field intensity, X2: Sonication time, SS: Sum of squares, and P-value: Probability value.

Fig. 2 Effects of (a) electric field intensity and (b) sonication time on the extraction efficiency.

Fig. 3 Scanning electron microscopy (SEM) images of (a) control and (b) treated sample by pulsed-electric field-ultrasonication at the optimum conditions.

Table 3 Model equations for the dependent variable.

Dependent variable	Equation	R2	R2-adj	CV	
Extraction efficiency (%)	Y= +5.16 + 0.85X1 + 0.98X2–0.29X12 – 0.53 X22–0.10X1X2	0.986	0.975	3.26	
TPC(mg gallic acid/100 g)	Y= +65.29 – 5.86X1 + 0.35X2–7.91X12 – 8.80 X22–6.26X1X2	0.880	0.793	7.63	
FRAP (mmol Fe/100 g)	Y= +0.30–0.03X1 + 0.002X2–0.054X12–0.049X22– 0.050X1X2	0.865	0.768	11.69	

3.2 Influence of extraction conditions on the phenolic content of extracts

Phenolic compounds are a broad category of herbal secondary metabolites. Their antioxidant power originates from the presence of hydroxyl groups in their structures. The use of natural phenolics in the food industry is growing, as these compounds retard lipid oxidation and raise the quality and nutritional value of food products [38]. Table 1 presents that the quadratic model was the best one for TPC (P=0.0024). Furthermore, ANOVA showed that all the model coefficients, except the linear term of the sonication time, significantly affected this response (P<0.05). Fig. 4 depicts that as the sonication time and EF intensity rose, the TPC of the extracts first increased and then decreased. The release of more phenolic compounds due to the application of UAE and PEF could be the reason behind this increase [21], [26]; the decrease was probably because of the destructive effect of long times of pretreatment. Borrás-Enríquez, et al. [39] examined the UAE of antioxidants from mango waste and came to the conclusion that a rise in the sonication time first elevated and then reduced the TPC of the extracts. Anticona, et al. [40] stated that as the sonication time increased up to 30 min, the TPC of the extracts of hybrid mandarin increased, too, which was in agreement with the results of the present study. Hosseini, et al. [21] investigated the extraction of corn meal antioxidants and cited that TPC of the extracts increased at low EF intensities, followed by a reduction at higher ones. Given the model coefficients (Table 3), it can be said that the quadratic effect of the sonication time most influenced the TPC.Fig. 4 Effects of electric field intensity and sonication time on total phenolic content of the extracts.

3.3 Changes in the antioxidant potential of the extracts

FRAP indicates the ability of a material to reduce trivalent iron (ferric) to the divalent one (ferrous). The presence of antioxidants (reducers/electron donors) in an extract result in the reduction of the ferricyanide complex to ferrous, where the yellow color of the solution changes into a variety of green and blue, depending on the FRAP of the extract [41]. Considering Table 1, it can be maintained that the quadratic model could best describe the variation in the data of RP (P=0.003). ANOVA results (Table 2) also revealed that like TPC, all the model components, except the linear effect of the sonication time, significantly influenced this response at P<0.05. Fig. 5 illustrates that FRAP experienced an increase followed by a decrease as the EF intensity and sonication time rose. The phenolic compounds of the extracts could break the chain reactions of free radicals by donating electrons or hydrogen atoms, thus procrastinating oxidation. The presence of reducing agents is the major reason behind FRAP, which shows their antioxidant activity by breaking the chain reaction of free radicals. As mentioned earlier, the rise and reduction in FRAP of the extracts could be ascribed to the increase and decrease in TPC of the extracts during extraction [42]. Shiekh, et al. [43] demonstrated that PEF elevated FRAP of apple leaf extract. Ilghami, et al. [44] assessed the UAE of antioxidant compounds from Beta vulgaris and expressed that as the sonication time increased, the FRAP of the extracts increased. According to the model terms (Table 3), it can be concluded that the quadratic effect of EF intensity had the most remarkable influence on the FRAP of the extracts.Fig. 5 Effects of electric field intensity and sonication time on the ferric-reducing power of extracts.

3.4 Extraction optimization results

Given that the EF intensity and sonication time varied in the ranges of 0.25–6.25 kV/cm and 20–60 min, respectively, the optimum conditions of the extraction process were found to be the EF intensity = 2.70 kV/cm and the sonication time = 45.83 min with the desirability of 0.871 to maximize EXE, TPC, and FRAP. Subsequently, the predicted and empirical results were compared (Table 4). It can be deduced that the application of PEF-ultrasound pretreatment under optimal conditions enhanced the EXE and antioxidant activity of yarrow extract, compared with the conventional method. Due to the low EXE of the extract, it is recommended to use mild heat treatments to potentially improve the EXE.Table 4 Comparison between properties of control and the treated sample at optimum conditions.

Response	PEF-ultrasound	Control	
Extraction efficiency (%)	5.23 ± 0.00a	2.65 ± 0.46b	
TPC (mg gallic acid/kg sample)	67.89 ± 00a	40.28 ± 3.23b	
FRAP (mmol Fe/100 g)	0.30 ± 0.00a	0.15 ± 0.05b	
The similar small letters in each column demonstrate non-significant differences at the significance level of 0.05.

3.5 Encapsulation efficiency of the extracts into nanoliposomes

Some factors such as wall material, interactions between the wall and core materials, and encapsulation technique influence ENE [45]. As shown in Table 5, ENEwas reduced at higher levels of the antioxidant extract in nanoliposomes. This could be due to the reduced concentration of the wall material used for the extract encapsulation. Hwang et al. [46] stated that as the phospholipid concentration was elevated, the number and internal volume of the liposomes increased, ending with a higher. This was consistent with our findings. Woodhead and Hall [47] evaluated the ENE and micellar structure of the nanoparticles of a mineral-carrying copolymer and observed the improvement of ENE with a rise in the wall polymer concentration. Ruengdech and Siripatrawan [48] investigated the effects of the type and concentration of wall material on enhancing the efficiency, stability, and antioxidant activity of catechin-loaded nanoemulsions prepared through foam-mat freeze drying. They declared that ENE lowered as the wall material concentration was reduced, particularly when maltodextrin was used alone, similar to the present study in which only lecithin was utilized as the wall material.Table 5 Some properties of prepared nanoliposomes containing yarrow extract.

Response	Concentration of yarrow extract (mL/mg)	
0	0.11	0.125	0.143	0.167	0.2	
Encapsulation efficiency(%)	0.00 ± 0.00f	69.38 ± 0.10a	63.15 ± 0.23b	59.64 ± 0.18c	50.55 ± 0.14cd	47.12 ± 0.15e	
Particle size (nm)	129.20 ± 1.17f	142.60 ± 1.27e	173.80 ± 2.31d	294.90 ± 0.21c	297.20 ± 0.85b	300.90 ± 1.01a	
PDI	0.287 ± 0.01f	0.307 ± 0.00e	0.329 ± 0.00d	0.398 ± 0.02c	0.420 ± 0.03b	0.461 ± 0.03a	
Zeta potential (mV)	−30.5 ± 0.23f	−28.15 ± 0.19e	−26.50 ± 0.41d	–22.61 ± 0.44c	−20.73 ± 0.08b	−10.25 ± 0.32a	
The similar small letters in each row demonstrate non-significant differences at the significance level of 0.05.

3.6 Size and surface charge of produced nanoliposomes

Measurement of particle size is one of the most important methods for confirming the production of nanocarriers [49], [50]. Our results showed that the extract concentration significantly affected the size of prepared nanoliposomes (P<0.05). As the concentration of yarrow extract increased in the nanoliposomes, they enlarged from 129.20 to 300.90 nm (Table 5). Given the application of water as the solvent for the antioxidant extraction, it can be deduced that these compounds were hydrophilic and their aggregation led to an increase in their sizes. At the same time, Zou, et al. [51] mentioned that a fraction of the core material may be adsorbed at the surface of liposomes, resulting in their enlargement. Ahmadi, et al. [52] encapsulated white tea in lecithin and cholesterol at different concentrations and claimed that an increase in the lecithin concentration lowered the particle sizes, owing to the better entrapment of the extract. Similarly, in the present research, since the wall-to-core ratio decreased, the nanoliposome sizes increased as the extract concentration rose.

Polydispersity index (PDI) is a measure of the homogeneity of nanoliposomal particles. As shown in Table 5, the PDI of the produced samples was in the range of 0.287–0.461, and the lowest PDI belonged to the extract-free nanoliposome. As the extract concentration was elevated in the nanoliposomes, PDI increased, too. Jambrak, et al. [53] maintained the smaller the particles, the lower the PDI, conforming to our results. Ruengdech and Siripatrawan [48] realized that PDI increased with a rise in the concentration of Arabic gum (wall material) in the encapsulation of catechin. The difference between this finding with ours may be owing to the difference in the core and wall materials used in the two studies.

Zeta potential shows the surface charge of lipid vesicles of each layer adsorbed at the interface in addition to the nature and composition of the medium in which liposomes are dispersed [54]. Additionally, this parameter indicates the number of repulsive interactions between colloidal particles and is applied for evaluating the stability of vesicle suspensions. There is little repulsive force between particles with low zeta potential, which ultimately coalesce and cause system instability. In general, if the zeta potential of a colloidal system exceeds ± 30 mV, the suspension will be stable in terms of electrostatic repulsive forces [55]. So, measurement of this quantity is a useful tool for controlling the aggregation and precipitation of nanoliposomes, which play key roles in their stability [56]. As the extract concentration increased, the zeta potential of the samples also increased (Table 5), all of which had negative charges. The reduction in the negative charge of the system with a rise in the extract concentration seems to be due to the more coverage of the liposome surfaces as a result of the decreased surface charge [57].

Based on the results of ENE, particle size, zeta potential, and PDI, the nanoliposome containing 0.11 mL of the antioxidant extract per mg of the nanoliposomes was selected as the best sample.

3.7 Morphology of the extract-loaded nanoliposomes

The morphological properties of nanocarriers are investigated using high-resolution microscopy techniques [58]. The structural properties of the empty (Fig. 6a) and extract-loaded (Fig. 6b) nanoliposomes were examined; it was revealed that the nanocarriers were relatively spherical or elliptical and adhesive with smooth surfaces. Spherical particles are more capable of controlling the release of bioactives, because of their less surface contact area with the surrounding medium. Also, such particles are more stable [59]. Ganji et al. [60] and Ahmadi et al. [52] prepared nanoliposomes loaded with hydrolyzed cannabis protein and white tea antioxidant extract, respectively. They cited that the nanoliposomes were spherical and stable, which is consistent with our findings.Fig. 6 SEM images of (a) empty and (b) extract-loaded nanoliposomes.

3.8 Thermal properties of extract-loaded nanoliposomes

The thermodynamic behavior of the extract-free nanoliposomes, yarrow extract, and nanoliposomal extracts containing 0.11 mL/mg of the extract are summarized in Table 6 and Fig. 7. The extract-loaded nanoliposomes had the highest enthalpy (3600 J/g) followed by the extract itself. The higher enthalpy of the extract-containing nanoliposomes is probably caused by the extract phenolic compounds as well as the lipid compounds on the nanoliposome surfaces, which were intensely bound with each other through hydrogen bonds. In addition, phenolic compounds inhibited the oxidation of the liposomes‘ polar lipids, thus raising thermal stability [57]. On the other hand, all the tested samples had endothermic peaks, and the decrease in the melting points of the nanoliposomes could be attributed to the impurities of the raw lecithin, which are a combination of other phospholipids and soybean oil. The reduction in melting point during the liposome formation could be because the particle sizes decreased, compared with the aggregated particles, thus bringing about a decrease in the melting point. Bunjes and Unruh [61] indicated that the melting point of the produced nanoparticles was lower than that of pure lecithin. Our results are in agreement with those previously reported by Rashidinejad, et al. [62] who applied DSC to evaluate the thermodynamic behavior and stability of green tea catechin and epigallocatechin gallate encapsulated in liposomes, and with those of Savaghebi et al. [46] who used DSC to determine the phase transition of nanoliposomal extract from Sargassum boveanum algae.Table 6 Effect of sample type on thermal properties.

Type of sample	Parameter measured	
Melting onset (°C)	Enthalpy (J/g)	Melting point (°C)	
Empty nanoliposomes	109.99 ± 0.95b	2253 ± 8.63c	127.76 ± 5.04b	
Yarrow extract	114.64 ± 1.09a	2295 ± 10.56b	139.32 ± 1.43a	
Extract-loaded nanoliposomes	99.80 ± 1.05c	3600 ± 10.62a	124.84 ± 4.95b	
The similar small letters in each column demonstrate non-significant differences at the significance level of 0.05.

Fig. 7 Thermograms of (a) empty nanoliposomes, (b) yarrow extract, and (c) extract-loaded nanoliposomes.

3.9 FTIR results

FTIR spectroscopy is a useful tool for assessing the intermolecular interactions indicated by the displacement or broadening of the bands in the spectra [52]. As shown in Fig. 8, by comparing the FTIR spectra of the empty and extract-loaded nanoliposomes, the following indicative peaks were determined: 2922.77 and 2923.42 cm−1 indicating the C—H bonds of alkanes; 1740 cm−1 associated with aliphatic esters (stretching vibration of C <svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="20.666667pt" height="16.000000pt" viewBox="0 0 20.666667 16.000000" preserveAspectRatio="xMidYMid meet"><metadata> Created by potrace 1.16, written by Peter Selinger 2001-2019 </metadata><g transform="translate(1.000000,15.000000) scale(0.019444,-0.019444)" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 480 0 480 0 0 40 0 40 -480 0 -480 0 0 -40z M0 280 l0 -40 480 0 480 0 0 40 0 40 -480 0 -480 0 0 -40z"/></g></svg> O); and 1075 cm−1 related to the stretching vibration of C—O. These variations and displacements signify the encapsulation of the extract in the nanoliposomes [52]. Furthermore, since no new peaks appeared in the FTIR spectrum of the extract-loaded nanoliposome, and at the same time, no peak disappeared, it can be deduced that no chemical reaction occurred between the nanoliposome and the extract, and both retained their nature and did not change. In the case of the yarrow extract, the bands at 1078, 1733, and 2924 cm−1 respectively represent the hydroxyl groups, aromatic substances, and methylene. In the empty nanoliposomes, the bands near 3501 cm−1 pertaintothe stretching vibration of hydroxyl (O—H). Moreover, some information on a regular or irregular state (such as the acyl chain flexibility) in the lipid membrane can be obtained by examining the symmetric or asymmetric stretching vibrations of CH2, which are at 2828 and 3008 cm−1, respectively [63].Fig. 8 FTIR spectra of (a) empty nanoliposomes, (b) yarrow extract, and (c) extract-containing nanoliposomes.

3.10 The effect of antioxidant type on the oxidative stability of sesame oil

The oil Oxidative Stability Index (OSI) is widely used to evaluate and predict the oxidative stability of oils by the Ransimat device. This test is performed based on measuring the electrical conductivity of water while accumulating volatile compounds obtained from oil oxidation, especially carboxylic acids under accelerated oxidation conditions, and oil stability time is reported as an index of oxidation stability for oil at a certain temperature [64]. Fig. 9 shows that the highest oxidative stability (14.21 h) was related to the oil with nanoliposome containing 500 ppm Yarrow extract, followed by the sample containing 200 ppm BHT (13.59 h), free extract (12.42 h) and the sample without antioxidants (11.62 h). Bojmehrani, et al. [35] showed that the highest oxidation stability of soybean oil (7.6 h) was related to the sample with 500 ppm nanoliposome containing grape pomace antioxidant extract, followed by the sample containing BHT and the sample containing free grape pomace antioxidant extract. which was in confirmation of the results of this study. Lalas and Dortoglu [65] as well as Ramalho and Jorge [66] in increasing the oxidative stability of oil by other plant extracts by Rancimat test were consistent with the results of the present research.Fig. 9 Oxidative stability of sesame oils a) control, b) containing nanoliposomes, c) free extract, and d) BHT.

4 Conclusion

The purpose of this research was to raise the EXE of antioxidants from yarrow using PEF-ultrasound pretreatment, as well as to investigate some of the properties of the nanoliposomes loaded with the extract. The results showed that as the EF intensity and sonication time increased, EXE rose, whereas the TPC and FRAP of the extracts first increased and then decreased. Considering the maximization of EXE, TPC, and FRAP, the optimal conditions of the extraction were found to be the EF intensity = 270 kV/cm and the sonication time = 45.83 min. It was also realized that the application of PEF-ultrasound pretreatment in the optimum conditions resulted in an increase in the antioxidant activity and EXE, compared with the conventional extraction method. The results also demonstrated that an increase in the concentration of yarrow extract in the nanoliposomes reduced ENE but elevated the particle size, PDI, and zeta potential of the samples. The FTIR results also denoted the successful encapsulation of the antioxidant extract in the nanoliposomes. Eventually, the nanoliposomes containing 0.11 mL/mg of the extract were chosen as the optimum sample. it can be stated that the use of nanoliposome containing Yarrow plant extract is a suitable alternative for synthetic antioxidants available in the market. The use of nanoliposome-containing yarrow extract is a suitable alternative to synthetic antioxidants available in the market.

5 CRediT role of authors

Elaheh Razghandi performed the experiments and wrote the first draft of the original manuscript. Amir Hossein Elhami Rad created some Tables and Figures and completed the manuscript for submission. Seid Mahdi Jafari designed the experiments, drafted the outline, supplied guidance, and critically reviewed and finalized the manuscript. Mohammad Reza Saiedi Asl and Hamid Bakhshabadi reviewed the manuscript.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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References

1 Chang Q. Zuo Z. Harrison F. Chow M.S.S. Hawthorn J. Clin. Pharmacol. 42 2002 605 612 12043949
2 Liu P. Yang B. Kallio H. Characterization of phenolic compounds in Chinese hawthorn (Crataegus pinnatifida Bge. var. major) fruit by high performance liquid chromatography–electrospray ionization mass spectrometry Food Chem. 121 2010 1188 1197
3 Cui H.-Y. Jia X.-Y. Zhang X. Zhang J. Zhang Z.-Q. Optimization of high-speed counter-current chromatography for separation of polyphenols from the extract of hawthorn (Crataegus laevigata) with response surface methodology Sep. Purif. Technol. 77 2011 269 274
4 Tracy T.S. Kingston R.L. Herbal Products: toxicology and clinical pharmacology 2007 Springer Science & Business Media
5 Grosso C. Vinholes J. Silva L.R. Pinho P.G. Gonçalves R.F. Valentão P. Jäger A.K. Andrade P.B. Chemical composition and biological screening of Capsella bursa-pastoris Rev. Bras 21 2011 635 643
6 Kuroda K. Pharmacologcial and anticarcinogenic effects of capsella bursa-pastoris Extract Chiba Med 65 1989 67 74
7 Taheri Leong S.Y. Oey I. Burritt D.J. Pulsed electric field improves the bioprotective capacity of purées for different coloured carrot cultivars against H2O2-induced oxidative damage Food Chem. 196 2016 654 664 26593539
8 Bariş Ö, Güllüce M, ŞAHİN F, Özer H, Kiliç H, Özkan H, Sökmen M, Özbek T (2006) Biological activities of the essential oil and methanol extract of Achillea biebersteinii Afan.(Asteraceae). Turkish Journal of Biology 30: 65-73.
9 Akkol EK, Koca U, Pesin I, Yilmazer D (2011) Evaluation of the wound healing potential of Achillea biebersteinii Afan.(Asteraceae) by in vivo excision and incision models. Evidence-Based Complementary and Alternative Medicine 2011.
10 Budrat P. Shotipruk A. Enhanced recovery of phenolic compounds from bitter melon (Momordica charantia) by subcritical water extraction Sep. Purif. Technol. 66 2009 125 129
11 Mohamadi M. Maskooki A. Mortazavi S. Evaluation of antioxidant properties of Barberry fruits extracts using maceration and subcritical water extraction (SWE) Int. J. Nutrition Food Eng. 6 2012 699 703
12 Lingyun W. Jianhua W. Xiaodong Z. Da T. Yalin Y. Chenggang C. Tianhua F. Fan Z. Studies on the extracting technical conditions of inulin from Jerusalem artichoke tubers J. Food Eng. 79 2007 1087 1093
13 Romdhane M. Gourdon C. Investigation in solid–liquid extraction: influence of ultrasound Chem. Eng. J. 87 2002 11 19
14 Oroian M. Ursachi F. Dranca F. Influence of ultrasonic amplitude, temperature, time and solvent concentration on bioactive compounds extraction from propolis Ultrason. Sonochem. 64 2020 105021
15 Dzah C.S. Duan Y. Zhang H. Wen C. Zhang J. Chen G. Ma H. The effects of ultrasound assisted extraction on yield, antioxidant, anticancer and antimicrobial activity of polyphenol extracts: a review Food Biosci. 35 2020 100547
16 Quiroz-Reyes C.N. Aguilar-Méndez M.Á. Continuous ultrasound and pulsed ultrasound: selective extraction tools to obtain enriched antioxidants extracts from cocoa beans (Theobroma cacao L.) Innov. Food Sci. Emerg. Technol. 80 2022 103095
17 Sirichan T. Kijpatanasilp I. Asadatorn N. Assatarakul K. Optimization of ultrasound extraction of functional compound from makiang seed by response surface methodology and antimicrobial activity of optimized extract with its application in orange juice Ultrason. Sonochem. 83 2022 105916
18 Toepfl S. Mathys A. Heinz V. Knorr D. Potential of high hydrostatic pressure and pulsed electric fields for energy efficient and environmentally friendly food processing Food Rev. Intl. 22 2006 405 423
19 Leong SY, Oey I, Burritt D J (2016) Pulsed electric field improves the bioprotective capacity of purées for different coloured carrot cultivars against H2O2-induced oxidative damageFood chemistry196: 654-664.
20 Bakhshabadi H. Mirzaei H. Ghodsvali A. Jafari S.M. Ziaiifar A.M. The influence of pulsed electric fields and microwave pretreatments on some selected physicochemical properties of oil extracted from black cumin seed Food Sci. Nutr. 6 2018 111 118 29387368
21 Hosseini S.M. Bojmehrani A. Zare E. Zare Z. Hosseini S.M. Bakhshabadi H. Optimization of antioxidant extraction process from corn meal using pulsed electric field-subcritical water J. Food Process. Preserv. e15458 2021
22 Fang Z. Bhandari B. Encapsulation of polyphenols–a review Trends Food Sci. Technol. 21 2010 510 523
23 Keller B.C. Liposomes in nutrition Trends Food Sci. Technol. 12 2001 25 31
24 Mozafari M.R. Liposomes: an overview of manufacturing techniques Cell. Mol. Biol. Lett. 10 2005 711 16341279
25 Werner A. Havinga R. Perton F. Kuipers F. Verkade H.J. Lymphatic chylomicron size is inversely related to biliary phospholipid secretion in mice. American Journal of Physiology-Gastrointestinal and Liver Physiology 290 2006 G1177 G1185
26 Moghimi M. Farzaneh V. Bakhshabadi H. The effect of ultrasound pretreatment on some selected physicochemical properties of black cumin (Nigella Sativa) Nutrire 43 2018 18
27 Huang B. He J. Ban X. Zeng H. Yao X. Wang Y. Antioxidant activity of bovine and porcine meat treated with extracts from edible lotus (Nelumbo nucifera) rhizome knot and leaf Meat Sci. 87 2011 46 53 20869815
28 Bakhshabadi H. Mirzaei H. Ghodsvali A. Jafari S.M. Ziaiifar A.M. Farzaneh V. The effect of microwave pretreatment on some physico-chemical properties and bioactivity of Black cumin seeds’ oil Ind. Crop. Prod. 97 2017 1 9
29 Xia S. Xu S. Ferrous sulfate liposomes: preparation, stability and application in fluid milk Food Res. Int. 38 2005 289 296
30 Sarabandi K. Mahoonak A.S. Hamishehkar H. Ghorbani M. Jafari S.M. Protection of casein hydrolysates within nanoliposomes: antioxidant and stability characterization J. Food Eng. 251 2019 19 28
31 Marsanasco M. Márquez A.L. Wagner J.R. Alonso S.V. Chiaramoni N.S. Liposomes as vehicles for vitamins E and C: an alternative to fortify orange juice and offer vitamin C protection after heat treatment Food Res. Int. 44 2011 3039 3046
32 Pople P.V. Singh K.K. Development and evaluation of colloidal modified nanolipid carrier: application to topical delivery of tacrolimus Eur. J. Pharm. Biopharm. 79 2011 82 94 21447390
33 Sarabandi K. Jafari S.M. Effect of chitosan coating on the properties of nanoliposomes loaded with flaxseed-peptide fractions: stability during spray-drying Food Chem. 310 2020 125951
34 Seetapan N. Bejrapha P. Srinuanchai W. Ruktanonchai U.R. Rheological and morphological characterizations on physical stability of gamma-oryzanol-loaded solid lipid nanoparticles (SLNs) Micron 41 2010 51 58 19726202
35 Bojmehrani A. Hajirostamloo B. Vazifedoost M. Didar Z. Jafari S.M. The effect of nanoliposomes containing antioxidant extract of grape pomace on oxidation parameters of soybean oil J. Food Sci. Technol. (Iran)19 2022 171 182
36 Schroeder S, Buckow R, Knoerzer K, 2009. Numerical simulation of pulsed electric fields (PEF) processing for chamber design and optimisation, Seventh International Conference on CFD in the Minerals and Process Industries, CSIRO, Melbourne, Australia. pp. 9-11.
37 Shorstkii I. Mirshekarloo M. Koshevoy E. Application of pulsed electric field for oil extraction from sunflower seeds: Labscale parametersoptimization IRC Conference on Science 2015 Engineering and TechnologyIRC-SET)
38 Huang Muanda F.N. Soulimani R. Diop B. Dicko A. Study on chemical composition and biological activities of essential oil and extracts from Stevia rebaudiana Bertoni leaves LWT-Food Sci. Technol. 44 2011 1865 1872
39 Borrás-Enríquez A.J. Reyes-Ventura E. Villanueva-Rodríguez S.J. Moreno-Vilet L. Effect of ultrasound-assisted extraction parameters on total polyphenols and its antioxidant activity from mango residues (Mangifera indica L Var. Manililla). Separations 8 2021 94
40 Anticona M. Blesa J. Lopez-Malo D. Frigola A. Esteve M.J. Effects of ultrasound-assisted extraction on physicochemical properties, bioactive compounds, and antioxidant capacity for the valorization of hybrid Mandarin peels Food Biosci. 42 2021 101185
41 Do Q.D. Angkawijaya A.E. Tran-Nguyen P.L. Huynh L.H. Soetaredjo F.E. Ismadji S. Ju Y.-H. Effect of extraction solvent on total phenol content, total flavonoid content, and antioxidant activity of Limnophila aromatica J. Food Drug Anal. 22 2014 296 302 28911418
42 Esmaeelian M. Jahani M. Einafshar S. Feizy J. Optimization of experimental parameters in subcritical water extraction of bioactive constituents from the saffron (Crocus sativus L.) corm based on response surface methodology J. Food Meas. Charact. 2020 1 11
43 Shiekh K.A. Olatunde O.O. Zhang B. Huda N. Benjakul S. Pulsed electric field assisted process for extraction of bioactive compounds from custard apple (Annona squamosa) leaves Food Chem. 359 2021 129976
44 Ilghami A. Ghanbarzadeh S. Hamishehkar H. Optimization of the ultrasonic-assisted extraction of phenolic compounds, ferric reducing activity and antioxidant activity of the Beta vulgaris using response surface methodology Pharmaceutical Sciences 21 2015 46 50
45 Savaghebi D. Barzegar M. Mozafari M.R. Manufacturing of nanoliposomal extract from Sargassum boveanum algae and investigating its release behavior and antioxidant activity Food Sci. Nutr. 8 2020 299 310 31993156
46 Hwang SY, Kim HK, Choo J, Seong GH, Hien TBD, Lee E (2012) Effects of operating parameters on the efficiency of liposomal encapsulation of enzymesColloids and Surfaces B: Biointerfaces, 94: 296-303.
47 Woodhead J.L. Hall C.K. Encapsulation efficiency and micellar structure of solute-carrying block copolymer nanoparticles Macromolecules 44 2011 5443 5451 21918582
48 Ruengdech A. Siripatrawan U. Improving encapsulating efficiency, stability, and antioxidant activity of catechin nanoemulsion using foam mat freeze-drying: the effect of wall material types and concentrations LWT 162 2022 113478
49 Angkawijaya Benavente-Garcıa O. Castillo J. Lorente J. Ortuño A. Del Rio J. Antioxidant activity of phenolics extracted from Olea europaea L. leaves Food Chem. 68 2000 457 462
50 Shah R, Eldridge D, Palombo E, Harding I (2014) Optimisation and stability assessment of solid lipid nanoparticles using particle size and zeta potentialJournal of physical science 25: 1.
51 Zou L.-q. Liu W. Liu W.-l. Liang R.-h. Li T. Liu C.-m. Cao Y.-l. Niu J. Liu Z. Characterization and bioavailability of tea polyphenol nanoliposome prepared by combining an ethanol injection method with dynamic high-pressure microfluidization J. Agric. Food Chem. 62 2014 934 941 24428744
52 Ahmadi E. Elhamirad A.H. Mollania N. Saeidi Asl M.R. Pedramnia A. Incorporation of white tea extract in nano-liposomes: optimization, characterization, and stability J. Sci. Food Agric. 102 2022 2050 2060 34562028
53 Jambrak A.R. Mason T.J. Lelas V. Paniwnyk L. Herceg Z. Effect of ultrasound treatment on particle size and molecular weight of whey proteins J. Food Eng. 121 2014 15 23
54 Gregoriadis G (2006) Liposome Technology, Vol. I. Liposome Preparation and Related Techniques. 3rd Ed CRC Press USA.
55 Luo Y. Zhang B. Whent M. Yu L.L. Wang Q. Preparation and characterization of zein/chitosan complex for encapsulation of α-tocopherol, and its in vitro controlled release study Colloids Surf. B Biointerfaces 85 2011 145 152 21440424
56 Gregoriadis Lin L. Cui H. Zhou H. Zhang X. Bortolini C. Chen M. Liu L. Dong M. Nanoliposomes containing Eucalyptus citriodora as antibiotic with specific antimicrobial activity Chem. Commun. 51 2015 2653 2655
57 Gibis M. Vogt E. Weiss J. Encapsulation of polyphenolic grape seed extract in polymer-coated liposomes Food Funct. 3 2012 246 254 22116575
58 Sarabandi K. Peighambardoust S.H. Mahoonak A.S. Samaei S.P. Effect of carrier types and compositions on the production yield, microstructure and physical characteristics of spray dried sour cherry juice concentrate J. Food Meas. Charact. 11 2017 1602 1612
59 Rabelo R.S. Oliveira I.F. da Silva V.M. Prata A.S. Hubinger M.D. Chitosan coated nanostructured lipid carriers (NLCs) for loading Vitamin D: a physical stability study Int. J. Biol. Macromol. 119 2018 902 912 30063935
60 Ganji S. Sani A.M. Mahdian E. Sayyed-Alangi Z. Physical characteristics of nanoliposomes prepared from hydrolyzed cannabis protein J. Appl. Bio. Biotechnol. 8 2020 6
61 Bunjes H. Unruh T. Characterization of lipid nanoparticles by differential scanning calorimetry, X-ray and neutron scattering Adv. Drug Deliv. Rev. 59 2007 379 402 17658653
62 Rashidinejad A. Birch E.J. Sun-Waterhouse D. Everett D.W. Delivery of green tea catechin and epigallocatechin gallate in liposomes incorporated into low-fat hard cheese Food Chem. 156 2014 176 183 24629955
63 Bilge D. Sahin I. Kazanci N. Severcan F. Interactions of tamoxifen with distearoyl phosphatidylcholine multilamellar vesicles: FTIR and DSC studies Spectrochim. Acta A Mol. Biomol. Spectrosc. 130 2014 250 256 24792199
64 Maghsoudlou E. Esmaeilzadeh Kenari R. Raftani Amiri Z. Evaluating antioxidant properties of pulp and skin of fig extracts and application in canola oil as replacing synthetic antioxidant.Iranian Food Sci. Technol. Res. J. 13 2017 503 516
65 Lalas S, Dourtoglou V (2003) Use of rosemary extract in preventing oxidation during deep-fat frying of potato chips.Journal of the American oil chemists' society 80: 579-583.
66 Ramalho V C, Jorge N (2208) Antioxidant action of rosemary extract in soybean oil submitted to thermoxidation.Grasas y aceites59: 128-131.
