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Article

Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions

by
Marzanna Hęś
1,
Wojciech Antkowiak
2,*,
Kinga Stuper-Szablewska
3,
Krzysztof Dziedzic
4,
Marta Jessa
1 and
Paulina Ratajczak
1
1
Department of Gastronomy Science and Functional Foods, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 28, 60-637 Poznań, Poland
2
Department of Botany, Faculty of Agronomy, Horticulture and Bioengineering, Poznań University of Life Sciences, Wojska Polskiego 28, 60-637 Poznań, Poland
3
Department of Chemistry, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 28, 60-637 Poznań, Poland
4
Department of Food Technology of Plant Origin, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 28, 60-637 Poznań, Poland
*
Author to whom correspondence should be addressed.
Agriculture 2024, 14(10), 1790; https://doi.org/10.3390/agriculture14101790
Submission received: 29 July 2024 / Revised: 7 October 2024 / Accepted: 9 October 2024 / Published: 12 October 2024
(This article belongs to the Special Issue The Impact of Environmental Factors on the Quality of Horticultural Commodities)
Browse Figure
Versions Notes

Abstract

:
Analyses were conducted on extracts from the fruits of P. pyraster and P. ×myloslavensis. Extraction with 80% methanol was performed at room temperature. The total phenolic content was determined by spectrophotometry using the Folin–Ciocalteu reagent, with gallic acid as the reference standard. Phenolic compounds and organic acids were identified on a liquid chromatograph. The antioxidative activity of the extracts was tested in relation to linoleic acid incubation of the emulsions for 19 h based on the neutralization of the DPPH radical (2,2-diphenyl-1-picrylhydrazyl) and the ABTS cation radical (2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid]) as well as by the ferric reducing antioxidant power (FRAP) assay. The analyses showed that the extract from P. pyraster fruits is characterized by a higher content of phenolic compounds and a higher antioxidative potential compared with that from P. ×myloslavensis. In extracts of both pear species, seven phenolic compounds and four organic acids were identified. The total fiber content in pears of P. pyraster and P. ×myloslavensis was determined at 36.45 g and 24.74 g/100 g d.m. of the pear fruits, of which most comprised the insoluble fraction (32.49 g and 20.86/100 g, respectively). The results of the conducted research are highly significant, as they confirm that pears contain many valuable nutrients and biologically active compounds, including antioxidants and dietary fiber. Adding pear extracts to food products may offer a way to boost their health benefits while also broadening the variety of items that have appealing sensory characteristics. Moreover, research has shown that fruit extracts can help to prolong the shelf life of food products by safeguarding them against lipid oxidation and the decline in their nutritional value.

1. Introduction

As the World Health Organization (WHO) reports, nutrition is the key factor affecting public health. Some evidence confirms that nutrition can have a positive effect on public health worldwide. This suggests that a suitable diet may prevent or even support the treatment of certain diet-dependent diseases [1]. The recommendation is to consume five servings of vegetables and fruit daily. Such an amount is crucial for the maintenance of a healthy diet by enriching it with essential nutrients, e.g., vitamins, minerals, dietary fiber, and, most of all, antioxidants. It has been shown that the consumption of adequate servings of vegetables and fruit may strengthen the immune system, as well as prevent cardiovascular disease, diabetes, certain cancers, and obesity [2]. Evidence has been shown that confirms an inverse proportional relationship between the incidence of obesity and the antioxidative capacity of the diet [3]. Fruit and vegetables are the main sources of antioxidants, such as polyphenolics, vitamin C, and carotenoids [4]. Antioxidants may inhibit the development of various diseases due to their properties. One of them is the ability to suppress the action of free radicals and prevent their oxidation. Neutralization of free radicals protects cells in the living organism against their detrimental action [5].
Materials rich in nutrients and bioactive compounds showing health-promoting properties also include pear fruits. For example, these fruits contain dietary fiber, minerals (magnesium, calcium, copper, iron, manganese, potassium, phosphorus, sodium, zinc, and iodine) and vitamins (C, E, B1, B2, B3, B6, K, and folic acid) [6,7,8]. Pears constitute a rich source of polyphenols (epicatechins, rutin, and chlorogenic acid) as well as anti-inflammatory triterpenes (ursolic and oleanolic acids). These are contained in both the skin and flesh of fruits; however, higher concentrations of these compounds can be found in the outer layers. The components mentioned above exert a beneficial effect on the human organism. Polyphenols are attributed antioxidative properties, while triterpenes exhibit an anti-inflammatory capacity [7]. Studies have shown that pear fruits can be characterized by an approx. 2-fold greater free radical scavenging capacity compared with peaches and apricots, while this is lower than the capacity of bilberry and cranberry [9]. Fruits of different pear varieties, e.g., Asian (=Japanese, Nashi, Chinese) P. pyrifolia (Burm.f.) Nakai, are rich in pectins. Galacturonic acid is their main structural component. Conducted analyses [10] showed that fruits of the Asian pears ‘Shinseiki’, ‘Chojuro’ and ‘Hosui’ contain from 0.61% to 0.78% pectins. These are beneficial for human health, since pectins constitute soluble (fermentable) dietary fiber, which, among other things, prevents constipation, binds harmful metals, and reduces the risk of cardiovascular disease by reducing the levels of LDL cholesterol.
Currently, in many countries, new species of plants with edible fruits rich in biologically active substances are sought after [11,12]. One of the pear species that deserves particular attention is the European wild pear, P. pyraster (L.) Burgsd. (=P. communis var. pyraster L.). It is found in southern, central, and western Europe. Pyrus pyraster is a type of tree that, when exposed to water shortage, tolerates dry substrates and high temperatures. In view of the documented global effects of climate change, the role of thermophilic tree species in forests will be increasing thanks to their high biocenotic value and adaptability to changing environmental conditions. Pears could be used on a broader scale both in forestry and in agricultural areas, replacing more sensitive tree species [13].
A new pear species is a spontaneous hybrid of the common pear P. communis L. (=P. communis subsp. communis L., P. domestica Medik.) and the willow-leafed pear P. salicifolia Pall., which is alien to Polish flora but which has been planted in European parks since 1780. This hybrid taxon, named Pyrus ×myloslavensis, was recently discovered and described by Antkowiak et al. in 2008 [14], who performed a comparative characterization (with reference to the parent taxa) concerning its flower and fruit morphology, as well as of its leaf morphology and anatomy. The goal of subsequent studies on P. ×myloslavensis was to determine whether the intermediate nature of this taxon would be evident in the pollen and seed anatomy and morphology [15]. In addition, the authors evaluated self-compatibility and crossability based on the observation of pollen tube growth. The investigations were carried out using light, fluorescence, and electron microscopy techniques and flow cytometry. P. ×myloslavensis is a highly interesting object of botanical and pomological research, and the data in this article are new and completely original.
Pear fruits, including those of uncultivated species, deserve greater attention as a valuable raw material for health-promoting food. There are few studies describing the antioxidative action of the polyphenols contained in pear, which may be successfully used in the production of preparations used in the development of new food products. Thus, the aim of the conducted investigations was to determine the phenolic content and antioxidative activity of extracts from P. pyraster and P. ×myloslavensis fruits. Lipid-free model systems (examining the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′ azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, and the ferric reducing antioxidant power (FRAP)) as well as systems containing emulsified linoleic acid were carried out. Furthermore, the total content of dietary fiber and its fractions was also determined in the pear fruits.

2. Materials and Methods

2.1. Chemicals

The following chemicals were used: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′ azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Folin–Ciocalteu reagent (FCR), 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ), gallic acid (GAE), (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), linoleic acid, 2-(N-Morpholino)ethanesulfonic acid (MES), 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS) thermostable (Sigma-Aldrich, Darmstadt, Germany), α-amylase, pepsin, amyloglucosidase (Megazyme, Ireland); acetone, acetic acid, sodium acetate × 3 H2O, ethanol, hydrochloric acid, iron(III) chloride hexahydrate, sodium carbonate, potassium persulfate, dipotassium hydrogen phosphate and potassium hydroxide were purchased from POCh (Polskie Odczynniki Chemiczne, eng. Polish Chemical Reagents, Gliwice, Poland). All chemicals and solvents used were of analytical grade.

2.2. Preparation of Extracts

Analyses were conducted on pear fruits collected at the beginning of October 2021 from 5 P. ×myloslavensis trees growing in the garden of the Department of Botany, Poznań University of Life Sciences and 4 P. pyraster trees growing in Poznań county. The relevant environmental parameters of the experimental garden of the Department of Botany of the University of Life Sciences in Poznan, in which the P. ×myloslavensis trees were grown, are shown in Table 1. P. pyraster trees grew in the wild in mid-field woodlots, several kilometers away from P. ×myloslavensis. Pear trees of both species were not fertilized or watered.
In soil, the content of the following minerals was determined in an extract of 0.03 M CH3COOH by the following methods: N-NH4—by the distillation method according to Bremmer with Starck modification; N-NO3—by the potentiometric method using ionoselenium electrodes; P—colorimetrically with ammonium vanadomolybdate; K, Ca, Mg—by the atomic absorption method; pH in H2O—potentiometrically; salt concentration—conductometrically.
The harvested fruits were cut into pieces, and the seeds and pedicels were removed, while overripe fruits were discarded. The fruits were frozen at −80 °C, lyophilized, and ground to produce a powder of uniform grain size. The material was then extracted with 80% methanol in a 1:5 ratio (25 g powder: 125 mL of methanol). Samples were shaken in a water bath at room temperature for 24 h, and then the extract was filtered and subsequently centrifuged for 10 min at 3000 RPM. The supernatant was transferred to a round-bottom flask, and methanol was distilled in a Rotavapor R-215 rotary evaporator (Chemland, Stargard, Poland). The resulting extract was frozen at −30 °C for 24 h and then lyophilized.

2.3. Preparation of the Linoleic Acid Emulsion

A total of 0.5 mL of Tween 20 was added to 5 mL of 1 M K2HPO4 and mixed for 5 min using a magnetic stirrer. Then, after 10 min, 0.5 mg of linoleic acid and 0.4 g of KOH were added and stirred for 2 min. In the next step, 11 mL of 1 M K2HPO4 was added and stirred for 10 min. After the addition of 150 mL of distilled water, the emulsion was stirred for 5 min and adjusted to a pH of 7.2 [16].

2.4. Analytical Methods

2.4.1. Determination of Total Phenolic Compound Content

The FCR (Folin–Ciocalteu reagent) method [17] was used to determine the total level of phenolic substances in the extract. A sample of the extract (0.2 mL containing 0.2–0.5 mg of extract) was mixed with 8.3 mL of distilled water and 0.5 mL of the FCR. The resulting test material was blended with 1 mL of saturated sodium carbonate solution. Subsequently, the mixture was incubated for 30 min at room temperature, and then a reading of the absorbance was carried out at 750 nm (Specord 40). The results are presented in mg of gallic acid equivalent per gram of dry matter extract (mg of GAE/g of d.m. extract).

2.4.2. Analysis of Phenolic Compound Content

Phenolic compounds and organic acids were identified in a ’Acquity UPLC H-class chromatography system (Waters, Milford, MA, USA). Chromatographic separation was performed on a UPLC®BEH C18 column (100 mm × 2.1 mm; particle size 1.7 μm) at 35 °C. The result was expressed in mg/g d.m. extract [18,19].

2.4.3. Determination of Dietary Fiber Content

The contents of insoluble and soluble dietary fiber were determined using the “AOAC Method 991.43 Total, Soluble, and Insoluble Dietary Fiber in Foods” [20]. The analysis involves the use of enzymes such as thermostable α-amylase (Megazyme, Bray, Ireland), pepsin and amyloglucosidase (Sigma-Aldrich, Darmstadt, Germany), which simulate the environment of the human digestive tract. The total dietary fiber content was calculated as the sum of the soluble and insoluble fractions. The results were expressed in mg/1 g d.m. pear. Analyses were performed using the Fibertec System 1023 apparatus by Tecator.

2.5. Antioxidative Activity of the Extract

2.5.1. Scavenging of DPPH Radicals

The capacity of the prepared extract to scavenge the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) was monitored using the method of Sanchez-Moreno et al. [21]. DPPH (1 mM, 0.25 mL) was dissolved in pure methanol and added to 0.1 mL of pear extracts (0.075–0.15 mg) with 2 mL of methanol. The decrease in absorbance of the resulting solution was determined at 517 nm after 30 min. The results are presented in mg of Trolox/g of d.m. extract.

2.5.2. Scavenging of ABTS Radicals

The radical cation was generated by combining a 7 mM ABTS•+ stock solution with 2.45 mM potassium persulfate in a 1:0.5 ratio (v/v) and allowing the mixture to react for 12–16 h until the reaction reached completion and the absorbance stabilized. The ABTS•+ solution was then diluted with ethanol to achieve an absorbance of 0.700 ± 0.02 at 734 nm for the measurements. The photometric assay involved adding 3.0 mL of ABTS•+ solution to 0.03 mL of the tested samples (concentration range: 0.015–0.15 mg/mL) and mixing for 1 min. Measurements were taken at 734 nm immediately after 6 min of reaction [22]. The results are expressed in mg Trolox per gram of dry matter extract.

2.5.3. Ferric Reducing Antioxidant Power (FRAP)

The FRAP reagent was prepared by combining 300 mM acetate buffer, 10 mL of TPTZ in 40 mM HCl, and 20 mM FeCl3 × 6H2O in a 10:1:1 ratio at 37 °C. Then, 3.0 mL of the FRAP reagent was mixed with 0.1 mL of the extracts at varying concentrations (0.05 mg/mL). The mixture was incubated in the dark at 37 °C for 4 min. The absorbance was recorded at 593 nm [23]. The results are expressed in mM Fe2+/L.

2.5.4. Emulsion System

The ability to inhibit linoleic acid autoxidation was determined using the method developed by Lingnert et al. [16]. This method uses a spectrophotometer to assess the increase in conjugated dienes in 10 mM linoleic acid emulsion at pH 7.2. A dose of 0.2 mL of pear extract was introduced at concentrations of 0.25 and 0.5% into the prepared emulsion. The absorbance of the sample was subsequently measured at wavelength λ = 234 nm immediately after the antioxidants were added. After 19 h of incubation at 37 °C and without access to light another measurement was done. The content of dienes was calculated using the molar absorptivity coefficient according to the Beer–Lambert law: A = ε × c × l, where A is the absorbance; ε is the molar absorptivity coefficient (ε = 2.56 × 104 dm3 · M−1 · cm−1); c is the concentration of peroxides with conjugated dienes (M); and l is the thickness of the absorbing layer (tray thickness = 1 cm).

3. Statistical Analysis

All statistical calculations were performed using Statistica software, ver. 13.3 (StatSoft Inc., Tulsa, OK, USA). The data were expressed as the mean ± standard deviation (SD) of 2 series and 3 independent measurements for each sample (n = 6). To determine whether a random sample came from a population with a normal distribution, the Student’s t-test was applied. In the case where the hypothesis on the normal distribution was rejected, non-parametric statistics were used in further analyses. Correlation and regression analyses between variables were performed. The dependence between variables was presented using Pearson’s linear correlation coefficient.

4. Results and Discussion

4.1. Extraction Efficiency and Total Phenolic Content

The extraction efficiency for fruits of wild pear P. pyraster and P. ×myloslavensis was 3.6% and 5.4%, respectively. Liaudanskas et al. [24] reported that a significant effect on the course of extraction in known European pear cultivars is exerted by time, temperature, and the concentration of the solvent. These authors stated that when ethanol was applied at various concentrations (20–96%), the best extraction capacity was found for the 70% solution. In turn, Patricia and Syaputri [25], when studying contents of bioactive compounds in cultivars of European and Asian pears, used both 80% methanol and ethanol in the extraction process. In both varieties, a better process yield was obtained when ethanol was used instead of methanol. In a study by Guiné et al. [26] on fruits of ‘Joaquina’ P. communis, the mean extraction efficiency before the drying process was 17.23%, while this efficiency increased with a higher temperature (60 °C and 70 °C) and a longer duration of the extraction process.
Another factor affecting the amount of extracted material was the polarity of the solvent. Dai and Mumper [27] showed that the use of methanol as a solvent is more advantageous in the case of phenolic compounds with a lower molecular mass, while it was acetone in the case of polyphenols with a higher molecular mass. Methanol is a polar substance; thus, it effectively extracts the phenolic compounds found in the polar, soluble part. Apart from the polarity and the type of the solvent, the efficiency of extraction is also affected by the type of analyzed material.
Du et al. [28] showed that even when working on one pear cultivar, the results may differ depending on the part of the fruit collected for analysis. The results were compared in terms of the content of phenolic compounds in the endocarp, exocarp, and hypanthium. In all cases, the highest contents were recorded in the exocarp (121.22–153.44 mg GAE/100 g), whereas the lowest were recorded in the hypanthium (56.78–61.22 mg GAE/100 g). Öztürk et al. [29], in their studies, also analyzed different fruit parts of the same pear cultivar. Their investigations showed that a greater proportion of phenolic compounds is found in the skin rather than in the flesh itself.
In this study, the extract from fruits of the wild pear P. pyraster was characterized by a 3-fold greater content of total phenolic compounds compared with that of P. ×myloslavensis fruits (197 mg and 61.7 mg GAE/g d.m. extract, respectively) (Table 2). Kopera and Mitek [30], using 80% methanol extracts from fruits of three cultivars of the Asian pear P. pyrifolia (‘Shinseiki’, ‘Hosui’, and ‘Chojuro’), showed the total content of phenolic compounds to be 102–141 mg GAE/g of d.m. extract, with a process efficiency of 11.9–13.0%. In turn, Wang et al. [31], reported a total content of polyphenols of 1.89–3.14 mg GAE/g d.m. extract in 70% ethanol extracts from the fruits of five P. communis cultivars (‘Beurre Bosc’, ‘Josephinede Malines’, ‘Rico’, ‘Packham’s Triumph’, and ‘Winter Nelis’). It was stated that the total phenolic content in extracts from fruits of P. pyraster and P. ×myloslavensis also exceeds that of ‘Ya Li’ P. bretschneideri (57.5 mg GAE/g d.m. extract), ‘Blanquilla’ P. communis (13 mg GAE/g d.m. extract), and ‘Conference’ P. communis (2.5 mg GAE/g d.m. extract [32]).

4.2. Determination of the Content of Phenolic Compounds and Organic Acids Using HPLC

In extracts from the fruits of P. pyraster and P. ×myloslavensis, a total of seven phenolic compounds (quercetin, catechin, epicatechin, ferrulic, chlorogenic, synapic, and vanillic acids) and four organic acids (citric, maleic, shikimic, and fumaric acids) were detected (Table 3). In the extracts, chlorogenic acid was found in the greatest amounts (0.1225 and 0.0762 mg/g d.m. extract from the fruits of P. pyraster and P. ×myloslavensis, respectively). This acid is a phenolic acid, classified in the group of hydroxycinnamic acids. In turn, among the organic acids, citric acid is found in the greatest amounts (0.0813 and 0.0440 mg/g d.m. extracts, respectively).
Carbonaro et al. [33] showed that among all phenolic compounds, chlorogenic acid is a compound commonly found in pear fruits. Kopera and Mitek [30] provided chemical characteristics of fruits from three of the P. pirifolia Asian pear cultivars (‘Shinseiki’, ‘Hosui’, and ‘Chojuro’). Those authors detected no statistically significant differences between these cultivars in terms of their phenolic acid content. They showed that the fruits of all the cultivars, both in the flesh and the skin, contain p-hydroxycinnamic acid and catechins. In the cultivars ‘Shinseiki’ and ‘Hosui’, the whole fruits also contained cinnamic and pyrocatechuic acid. In addition, var. ‘Hosui’ also contained p-coumaric acid.

4.3. DPPH Radical Scavenging Capacity

A greater DPPH radical scavenging capacity was recorded for the extract from fruits of P. pyraster (289.8 mg Trolox/g d.m. extract) compared with that of the extract from P. ×myloslavensis fruits (134.4 mg/g d.m. extract) (Table 2). Statistical analysis showed that the DPPH radical scavenging capacity in extracts from fruits of P. pyraster and P. ×myloslavensis is strongly positively correlated with their total phenolic content (p < 0.05; r = 0.99; Figure 1). Wang et al. [31] showed that DPPH radical scavenging capacity of ethanol extracts from fruits of five P. communis cultivars (‘Beurre Bosc’, ‘Josephinede Malines’, ‘Packham’s Triumph’, ‘Winter Nelis’, and ‘Rico’) ranged from 5.72 to 3.75 mg ascorbic acid/g d.m. extract. ‘Beurre Bosc’ of the P. communis cultivar showed the greatest DPPH radical scavenging capacity, while this was lowest in P. communis var. ‘Winter Nelis’. Ieguchi et al. [34] determined the DPPH radical scavenging capacity in 29 pear cultivars grown in Japan and Europe; for many cultivars, the results were comparable to those reported by Wang et al. [31]. The potential of the antioxidative capacity is influenced not only by the cultivar but also by the growing conditions, the degree of ripeness of the fruit, and even the conditions of its storage [35]. In turn, Manzoor et al. [36] determined the content of phenolic compounds and the DPPH radical scavenging capacity in the pulp and skin of pear fruits. They showed that both the content of polyphenols and the DPPH scavenging capacity are higher in the skin (49.71%) than in the pulp (27.89%). A strong dependence between total content of phenolic compounds and the DPPH radical scavenging capacity was also confirmed in the study by Li et al. [8]. Choi et al. [37] investigated five different ethanol–aqueous extracts of pear fruits and found that their DPPH radical scavenging capacity ranged from 17.4 to 30.3%. These results were lower compared with the activity of P. pyraster and P. ×myloslavensis when methanol was the extractant.

4.4. ABTS Cation Radical Scavenging Capacity

The extract from P. pyraster fruits showed an ABTS cation radical scavenging capacity of 11.33 mg Trolox/g d.m. of extract, while in the case of P. ×myloslavensis, it was 0.69 mg Trolox/g d.m. of extract (Table 2). The positive value of Pearson’s linear correlation coefficient (p < 0.05; r = 0.99; Figure 1) shows that there is a relationship between the ABTS cation radical scavenging capacity and the content of phenolic compounds in extracts from P. ×myloslavensis and P. pyraster. Also, Batista et al. [38] found a strong correlation (r = 0.99) between the antioxidative capacity of dried fruits of P. communis var. ‘Bartolomeu’ and ‘Amendoa’ and the total content of phenolic compounds. Erbil et al. [39] recorded the ABTS cation radical scavenging capacity in fruits of five Turkish cultivars of P. communis (‘Egirsah’, ‘Gugum’, ‘Deveci’, ‘Kizil’ and ‘Banda’) and found the highest activity in var. ‘Kizil’. In turn, Hu et al. [40] tested fruits of four Australian cultivars of sweet cherry, Prunus avium L. (‘Bing’, ‘Ron’s’, ‘Merchant’ and ‘Lapins’), and found their ABTS radical scavenging capacity to range from 0.51 to 0.37 mg ascorbic acid/g d.m. of extract. The highest ABTS scavenging capacity was recorded in var. ‘Merchant’, while it was lowest in var. ‘Lapins’. Nowak et al. [41] investigated the ABTS cation radical scavenging capacity in the fruit, skin, and leaves of plums extracted using various concentrations of both ethanol and methanol. Their analyses showed that the use of methanol as a solvent was the most effective. They also stated that in the fruit itself, the cation radical scavenging capacity was lower than in the other parts of the plant tested.

4.5. FRAP Reducing Potential

The extract from the fruits of P. pyraster showed reducing potential at 18.2 mM Fe(II). The activity of P. ×myloslavensis fruits was much lower, a value of 0.61 mM Fe(II) (Table 2). Based on the regression and correlation (p < 0.05; r = 0.99) it was stated that the capacity to reduce Fe(III) ions to Fe(II) ions by antioxidants contained in extracts from the fruits of P. pyraster and P. ×myloslavensis is very strongly positively correlated with the total phenolic content. Wang et al. [31] determined the reducing potential using the FRAP test for fruits of five P. communis cultivars (‘Beurre Bosc’, ‘Josephinede Malines’, ‘Packham’s Triumph’, ‘Winter Nelis’, and ‘Rico’) and showed a significantly different (p < 0.05) capacity for reducing Fe(III) ions to Fe(II) ions in the extracts tested. The reducing potential of the extracts ranged from 2.15 to 4.37 mg ascorbic acid/g d.m. of extract. The highest capacity was found for var. ‘Josephinede Maline’, while it was lowest for ‘Winter Nelis’. Jamuna et al. [42] recorded comparable antioxidative activity using the FRAP test for fruits of P. communis, with a reduction potential amounting to 3 mg of ascorbic acid/g d.m. of extract. Bahorun et al. [43], when analyzing lettuce, broccoli, carrot, cauliflower, onion, white cabbage, napa cabbage, chilli peppers, and tomato, showed a strong correlation (r = 0.83) between the investigated factors. Additionally, Dudonne et al. [44] reported an extraordinarily strong correlation between the content of phenols and the antioxidative capacity in the FRAP test (r = 0.906). In the same study conducted on chamomile (Matricaria recutita L.; 0.12 mM Fe (II)) and musk mallow (Abelmoschus moschatus Medik.; 0.08 mM Fe (II)), the results were lower compared with those obtained for extracts from the fruits of P. pyraster and P. ×myloslavensis. Slightly different data was reported by Sagbas et al. [45], who showed a moderate correlation between total phenolic content and the antioxidative capacity in the FRAP test for the pear P. elaeagrifolia Pall. (r = 0.489). In the analysis presented by Gouws et al. [46], a moderate correlation was also obtained between phenolic compounds and the capacity to reduce Fe(III) ions (r = 0.519) in fruits of the Indian fig opuntia.

4.6. Antioxidative Activity in Linoleic Acid Emulsion

The capacity of extracts from fruits of P. pyraster and P. ×myloslavensis to inhibit autoxidation of emulsified linoleic acid was tested at 0.25 and 0.5% addition levels (Table 4). After 19 h of thermal incubation of samples with various levels of pear fruit extracts added, the increase in peroxides with conjugated dienes was by 13.5% up to 80% lower compared with the control. A greater antioxidative activity has been observed for the extract from P. pyraster fruits than for of P. ×myloslavensis. The increased content of peroxides with conjugated dienes in the emulsion system after thermal incubation is very strongly negatively correlated with the concentration of the extracts (p < 0.05; r = −0.94 and p < 0.05; r = −0.84 for P. pyraster and P. ×myloslavensis, respectively). Along with the increase in concentration, a lower increment was recorded in the content of peroxides with conjugated dienes.
Hęś et al. [47] determined antioxidative activity of the aloe vera extract in the linoleic acid emulsion. Their analyses showed that the higher the concentration of Aloe vera extract added to the emulsion system, the lower the content of conjugated dienes after thermal incubation. Thus, an addition of the extract at 0.1–0.5 mg/mL to the emulsion system resulted in a 90% lower increase in conjugated dienes after thermal incubation compared to the control. In turn, addition of the extract at 0.05 mg/mL and 0.06 mg/mL inhibited (by 40% and 57%, respectively) the increase in conjugated dienes in the emulsion system following thermal incubation. Consequently, the results of both the experiment reported by Hęś et al. [47] and this study conclude that the concentration of the extract added to the emulsion system influences changes in the content of conjugated dienes after thermal incubation. The activity of pear extracts can be affected by the methods used for extracting phenolic compounds, the selection of solvents, and the particular part of the fruit from which the sample is taken (e.g., pear skin or pulp). Nevertheless, there is a lack of extensive research in the current literature on the antioxidative potential of pears in model systems, especially in emulsified fat systems, oils, and solid fats. More studies are needed to gain a deeper understanding of the role pear extracts play in these contexts and to investigate their potential for preserving the quality and extending the shelf life of fat-rich food products.

4.7. Dietary Fiber Content

Extracts from the fruits of P. pyraster have been characterized by higher contents of total fiber (36.45 g/100 g sample) and its insoluble fraction (32.49 g/100 g d.m. sample) compared with extracts from the fruits of P. ×myloslavensis (24.74 and 20.86 g/100 g d.m. sample, respectively). On the contrary, pears contain comparable amounts of the soluble fraction (approximately 3.70 g d.m. sample) (Table 5). It is worth noting that the insoluble dietary fiber fraction contains lignin, cellulose, and partially hemicellulose. Research so far has shown that the lignin fraction contains phenolic compounds, which are characterized by high antioxidative activity, as demonstrated through antioxidative activity analyses [48]. In our research, we observed the same trend—the antioxidative activity and the insoluble dietary fiber (IDF) fraction are higher in the P. pyraster sample.
Witkowska et al. [49] determined the total fiber content in Polish (sweet cherries, pears, apples, plums, strawberries, and black currants) and imported fruits (bananas, peaches, oranges, lemons, kiwi, and tangerines). They stated that in Polish fruits, the total content of dietary fiber in sweet cherries and red currants amounted to 1.14 g/100 g and 4.55 g/100 g. In turn, in imported fruits, the total fiber content in tangerines was 1.36 g/100 g and in lemons 2.89 g/100 g, respectively. Therefore, these authors reported a significantly lower total fiber content in the tested fruits compared with that in the lyophilizate produced from the fruits of P. pyraster and P. ×myloslavensis. The ratio of soluble fiber to total fiber in tested samples was 0.10:1 and 0.15:1, respectively, which is lower compared with the 0.39:1 ratio obtained from pear pomace [50,51]. Some tropical fruits show higher fiber contents compared with fruits grown in a temperate climate [52]. Moreno-Hernández et al. [53] analyzed fiber fractions in soursop Annona muricata L. from Mexico. The SDF level was greater (9.31 g/100 g sample) than in the extracts of the fruits of the investigated pears (Table 5). However, the total fiber content turned out to be greater in the tested pear fruits, as in soursop, it was 19.82 g/100 g of sample.

5. Conclusions

Results of research conducted worldwide confirm the health-promoting effect of consuming products rich in polyphenols and their extensive effect on the sensory attributes of food. It has been shown that materials rich in bioactive compounds exhibiting health-promoting properties also include fruits of P. pyraster and P. ×myloslavensis. Extracts from fruits of these pear species showed both high antioxidative potential and considerable dietary fiber content; thus, they may find applications in the food, pharmaceutical, and cosmetics industries. In the form of concentrate, gel, juice, or powder, they may be used as additives to numerous foodstuffs, enhancing their nutritive and health-promoting value while also improving their sensory attractiveness. Extracts from pear fruits may be added to jellies, jams, water, tea, juices, sweets, vitamin-enriched fruit smoothies, non-alcoholic beverages, isotonic drinks (with electrolytes), nutritional drinks and yogurts, as well as cream or cottage cheeses and ice-creams. An added aspect confirming the benefits resulting from the use of pear fruits in the food industry relates to their confirmed antioxidative activity in a linoleic acid emulsion. This property may be used to extend the shelf life of foodstuffs containing emulsified fat. The high content of active compounds in pear extracts makes them effective and safe food additives. However, the available literature is still lacking studies concerning the antioxidative potential of pear fruits in model systems, particularly in emulsified fat systems.
For this reason, exploring the most suitable applications and evaluating their effectiveness in food products with varying levels of processing is crucial. This could lead to the productive use of pears rich in bioactive compounds. The results obtained in this document clearly demonstrate the potential of pear extract to inhibit lipid autoxidation in food products, which justifies the need for further research. Now our attention is focused on the choice of antioxidants best suited for that purpose.

Author Contributions

Conceptualization, W.A. and M.H.; methodology, M.H.; validation, K.S.-S. and K.D.; formal analysis, K.D. and K.S.-S.; investigation, M.H., M.J. and P.R.; resources, W.A. and M.H.; data curation, M.J., P.R., K.D. and K.S.-S.; writing—original draft preparation, W.A. and M.H.; writing—review and editing, M.H. and W.A.; visualization, K.D.; supervision, M.H. and W.A.; project administration, M.H.; funding acquisition, M.H. and W.A. All authors have read and agreed to the published version of the manuscript.

Funding

This publication was financed by the Polish Minister of Science and Higher Education as part of the Strategy of the Poznan University of Life Sciences for 2024–2026 within the field of improving scientific research and development work in priority research areas.

Institutional Review Board Statement

Not applicable.

Data Availability Statement

The datasets used and/or analyzed during the current study are available from the first author upon reasonable request.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Medina-Vera, I.; Gómez-de-Regil, L.; Gutiérrez-Solis, A.L.; Lugo, R.; Guevara-Cruz, M.; Pedraza-Chaverri, J.; Avila-Nava, A. Dietary strategies by foods with antioxidant effect on nutritional management of dyslipidemias: A systematic review. Antioxidants 2021, 10, 225. [Google Scholar] [CrossRef] [PubMed]
  2. Arias, A.; Feijoo, G.; Moreira, M.T. Exploring the potential of antioxidants from fruits and vegetables and strategies for their recovery. Innow. Food Sci. Emerg. Technol. 2022, 77, 102974. [Google Scholar] [CrossRef]
  3. Davinelli, S.; Scapagnini, G. The Pharma-Nutritional Role of Antioxidant Phytochemicals in Health and Disease. Antioxidants 2022, 11, 1081. [Google Scholar] [CrossRef]
  4. Meitha, K.; Pramesti, Y.; Suhandono, S. Reactive oxygen species and antioxidants in postharvest vegetables and fruits. Int. J. Food Sci. 2020, 2020, 8817778. [Google Scholar] [CrossRef]
  5. Heydari, A.; Parvini, F.; Fard, N.A. Functional foods and antioxidant effects: Emphasizing the role of probiotics. In Current Topics in Functional Food; Shiomi, N., Savitskaya, A., Eds.; IntechOpen: London, UK, 2022; p. 280. [Google Scholar] [CrossRef]
  6. Hong, S.Y.; Lansky, E.; Kang, S.S.; Yang, M. A review of pears (Pyrus spp.), ancient functional food for modern times. BMC Complement. Med. Ther. 2021, 21, 219. [Google Scholar] [CrossRef]
  7. Li, X.; Wang, T.; Zhou, B.; Gao, W.; Cao, J.; Huang, L. Chemical composition and antioxidant and anti-inflammatory potential of peels and flesh from 10 different pear varieties (Pyrus spp.). Food Chem. 2014, 152, 531–538. [Google Scholar] [CrossRef]
  8. Li, X.; Zhang, J.Y.; Gao, W.Y.; Wang, Y.; Wang, H.Y.; Cao, J.G.; Huang, L.Q. Chemical composition and anti-inflammatory and antioxidant activities of eight pear cultivars. J. Agric. Food Chem. 2012, 60, 8738–8744. [Google Scholar] [CrossRef]
  9. Beliveau, R.; Gingras, D. Dieta w walce z rakiem. Profilaktyka i wspomaganie terapii przez odżywianie [Diet in the fight against cancer. In Prevention and Support of Therapy through Nutrition; Wydawnicza Delta WZ: Warsaw, Poland, 2010; pp. 140–143. (In Polish) [Google Scholar]
  10. Kopera, M.; Mitek, M.; Świeca, E. Zawartość substancji pektynowych w owocach trzech odmian gruszy azjatyckiej (Pyrus pyrifolia). [The content of pectin substances in fruit of three asian pear cultivars (Pyrus pyrifolia)]. Żywn. Nauka Technol. Jakość/Food. Sci. Technol. Quality. Suplement 2004, 3, 133. (In Polish) [Google Scholar]
  11. San-Martín-Hernández, C.; Martínez-Téllez, M.A.; Valenzuela-Amavizca, O.N.; Aispuro-Hernández, E.; Sánchez-Sánchez, M.; Hernández-Camarillo, E.; López-Martínez, L.X.; Eber Addí Quintana-Obregón, E.A. Byrsonima crassifolia L. Kunth a bio-resource with potential: Overview and opportunities. Folia Hort. 2023, 35, 61–75. [Google Scholar] [CrossRef]
  12. Cortiella, M.G.; Castro, R.I.; Parra-Palma, C.; Méndez-Yáñez, A.; Ramos, P.; Morales-Quintana, L. Analysis of the contents of Ugni molinae Turcz fruits across the ripening stages. Folia Hort. 2024, 36, 119–134. [Google Scholar] [CrossRef]
  13. Antkowiak, W.; Cedro, A.; Prajs, B.; Wolko, Ł.; Michalak, M. Success of wild pear Pyrus pyraster (L.) Burgsd. in colonization of steep sunny slopes: An interdisciplinary study in the Bielinek Reserve (NW Poland). Pol. J. Ecol. 2012, 60, 57–76. [Google Scholar]
  14. Antkowiak, W.; Czarna, A.; Wawrzyńska, M. Pyrus ×myloslavensis (P. communis L. × P. salicifolia Pall.)-A new spontaneons pear hybrid. Dendrobiology 2008, 60, 45–49. [Google Scholar]
  15. Antkowiak, W.; Maciejewska-Rutkowska, I.; Jędrzejczyk, I.; Wojciechowski, A. Morphological, anatomical and cytological characteristics of spontaneous hybrid Pyrus ×myloslavensis. Dendrobiology 2016, 75, 23–30. [Google Scholar] [CrossRef]
  16. Lingnert, H.; Vallentin, K.; Eriksson, C.E. Measurement of antioxidative effect in model system. J. Food Process. Preserv. 1979, 3, 87–103. [Google Scholar] [CrossRef]
  17. Horwitz, W. Official Methods of Analysis of the Association of Official Analytical Chemists; Association of Official Analytical Chemists: Washington, DC, USA, 1970; pp. 15.049–15.055. [Google Scholar]
  18. Telichowska, A.; Kobus-Cisowska, J.; Szulc, P.; Liga, j.M.; Stuper-Szablewska, K.; Szwajgier, D.; Bujak, H. Comparative analysis of infusions with the addtion P. padus bark: Assessment of the antioxidant potential and their inhibitory effect on enzymes associated with oxidative stress. Sustainability 2021, 13, 3913. [Google Scholar] [CrossRef]
  19. Przybylska-Balcerek, A.; Szablewski, T.; Szwajkowska-Michałek, L.; Świerk, D.; Cegielska-Radziejewska, R.; Krejpcio, Z.; Suchowilska, E.; Tomczyk, Ł.; Stuper-Szablewska, K. Sambucus nigra extracts-natural antioxidants and antimicrobial compounds. Molecules 2021, 26, 2910. [Google Scholar] [CrossRef]
  20. Helrich, K. Official Methods of Analysis of the Association of Official Analytical Chemists, 15th ed.; Association of Official Analytical Chemists United States: Arlington, VA, USA, 1990; ISBN 0-935584-42-0. [Google Scholar]
  21. Sanchez-Moreno, C.; Larrauri, J.A.; Saura-Calixto, F. A procedure to measure the antiradical efficiency of polyphenols. J. Sci. Food Agric. 1998, 76, 270–276. [Google Scholar] [CrossRef]
  22. Re, R.; Pellegrini, N.; Proteggente, A.; Pannala, A.; Yang, M.; Rice-Evans, C. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic. Biol. Med. 1999, 26, 1231–1237. [Google Scholar] [CrossRef]
  23. Fernandes, R.P.P.; Trindade, M.A.; Tonin, F.G. Evaluation of antioxidant capacity of 13 plant extracts by three different methods: Luster analyses applied for selection of the natural extracts with high er to replace synthetic antioxidant in lambburgers. J. Food Sci. Technol. 2016, 53, 451–460. [Google Scholar] [CrossRef]
  24. Liaudanskas, M.; Zymonė, K.; Viškelis, J.; Klevinskas, A.; Janulis, V. Determination of the phenolic composition and antioxidant activity of pear extracts. J. Chem. 2017, 2017, 7856521. [Google Scholar] [CrossRef]
  25. Patricia, V.M.; Syaputri, F.N. Antioxidant activities from two varieties of pear peel extracts using DPPH and CUPRAC methods. J. Phys. Conf. Ser. 2021, 1764, 012013. [Google Scholar] [CrossRef]
  26. Guiné, R.P.; Barroca, M.J.; Gonçalves, F.J.; Alves, M.; Oliveira, S.; Correia, P.M. Effect of drying on total phenolic compounds, antioxidant activity, and kinetics decay in pears. Int. J. Fruit Sci. 2015, 15, 173–186. [Google Scholar] [CrossRef]
  27. Dai, J.; Mumper, R.J. Plant phenolics: Extraction, analysis and their antioxidant and anticancer properties. Molecules 2010, 15, 7313–7352. [Google Scholar] [CrossRef] [PubMed]
  28. Du, B.; Cheng, C.; Chen, Y.; Wu, J.; Zhu, F.; Yang, Y.; Peng, F. Phenolic profiles and antioxidant activities of exocarp, endocarp, and hypanthium of three pear cultivars grown in China. J. Food Bioact. 2021, 14, 75–80. [Google Scholar] [CrossRef]
  29. Öztürk, A.; Demirsoy, L.; Demirsoy, H.; Asan, A.; Gül, O. Phenolic compounds and chemical characteristics of pears (Pyrus communis L.). Int. J. Food Prop. 2015, 18, 536–546. [Google Scholar] [CrossRef]
  30. Kopera, M.; Mitek, M. Charakterystyka chemiczna owoców wybranych odmian gruszy azjatyckiej (Pyrus pyrifolia). [Chemical characteristics of some selected cultivars of asian pear (Pyrus pyrifolia)]. Żywn. Nauka Technol. Jakość/Food. Sci. Technol. Quality. Suplement 2003, 10, 68–75. (In Polish) [Google Scholar]
  31. Wang, Z.; Barrow, C.J.; Dunshea, F.R.; Suleria, H.A. A comparative investigation on phenolic composition, characterization and antioxidant potentials of five different australian grown pear varieties. Antioxidants 2021, 10, 151. [Google Scholar] [CrossRef] [PubMed]
  32. Djendoubi, N.; Boudhrioua, N.M.; Kechaou, N.; Courtois, F.; Bonazzi, C. Influence of air drying temperature on kinetics, physicochemical properties, total phenolic content and ascorbic acid of pears. Food Bioprod. Process. 2012, 90, 433–441. [Google Scholar] [CrossRef]
  33. Carbonaro, M.; Mattera, M.; Nicoli, S.; Bergamo, P.; Cappelloni, M. Modulation of antioxidant compounds in organic vs conventional fruit (peach, Prunus persica L., and pear, Pyrus communis L.). J. Agric. Food Chem. 2002, 50, 5458–5462. [Google Scholar] [CrossRef]
  34. Ieguchi, T.; Katayama, H.; Nomura, K.; Takaoka, M.; Uematsu, C. Pear (Pyrus L.) genetic resources from Northern Japan: Evaluation of antioxidant capacity. Acta Hortic. 2015, 1094, 539–548. [Google Scholar] [CrossRef]
  35. Łysiak, G.P.; Rutkowski, K.; Walkowiak-Tomczak, D. Effect of storage conditions on storability and antioxidant potential of pears cv. Conference. Agriculture 2021, 11, 545. [Google Scholar] [CrossRef]
  36. Manzoor, M.; Anwar, F.; Bhatti, I.A.; Jamil, A. Variation of phenolics and antioxidant activity between peel and pulp parts of pear (Pyrus communis L.) fruit. Pak. J. Bot. 2013, 45, 1521–1525. [Google Scholar]
  37. Choi, J.J.; Lim, S.H.; Choi, J.H.; Park, J.H.; Nam, S.H.; Lee, H.C. Antioxidant activity of Pyrus pyrifolia fruit in different cultivars and parts. Korean J. Food Preser. 2013, 20, 222–226. [Google Scholar] [CrossRef]
  38. Batista, S.; Guiné, R.; Barroca, M.J.; Gonçalves, F.; González-SanJosé, M.L.; Rivero-Pérez, M.D. Evaluación de la composición fenólica y de la actividad antioxidante de peras frescas y secadas al sol (Pyrus communis L.). In Proceedings of the III Congreso Nacional de Ciência y Tecnología de los Alimentos, Burgos, Spain, 24–26 May 2005; pp. 947–950. [Google Scholar]
  39. Erbil, N.; Murathan, Z.T.; Arslan, M.; Ilcim, A.; Sayin, B. Antimicrobial, antioxidant and antimutagenic activities of five Turkish pear cultivars. Erwerbs. Obstbau. 2018, 60, 203–209. [Google Scholar] [CrossRef]
  40. Hu, T.; Subbiah, V.; Wu, H.; BK, A.; Rauf, A.; Alhumjdhi, F.A.; Suleria, H. Determination and characterization of phenolic compound from Australia-Grown sweet cherries (Prunus avium L.) and their potential antioxidant properties. Am. Chem. Soc. 2021, 6, 34687–34699. [Google Scholar] [CrossRef]
  41. Nowak, A.; Szatan, D.; Zielonka-Brzezicka, J.; Florkowska, K.; Muzykiewicz, A.; Klimowicz, A. Antioxidant activity of selected parts of Prunus domestica L. harvested at two ripening stages. Pomeranian J. Life Sci. 2020, 66, 65–69. [Google Scholar] [CrossRef]
  42. Jamuna, K.; Ramesh, C.; Srinivasa, T.; Raghu, R. In vitro antioxidant studies in some common fruit. Int. J. Pharm. Pharm. Sci. 2011, 3, 60–63. [Google Scholar]
  43. Bahorun, T.; Luximon-Ramma, A.; Crozier, A.; Aruoma, O.I. Total phenol, flavonoid, proanthocyanidin and vitamin C levels and antioxidant activities of Mauritian vegetables. J. Sci. Food Agric. 2004, 84, 1553–1561. [Google Scholar] [CrossRef]
  44. Dudonne, S.; Vitrac, X.; Coutiere, P.; Woillez, M.; Mérillon, J.M. Comparative study of antioxidant properties and total phenolic content of 30 plant extracts of industrial interest using DPPH, ABTS, FRAP, SOD, and ORAC assays. J. Agric. Food Chem. 2009, 57, 1768–1774. [Google Scholar] [CrossRef] [PubMed]
  45. Sagbas, H.I.; Ilhan, G.; Ercisli, S.; Anjum, M.A.; Holubec, V. Characterization of oleaster-leafed pear (Pyrus elaeagrifolia Pall. subsp. elaeagrifolia) fruits in Turkey. Agronomy 2021, 11, 430. [Google Scholar] [CrossRef]
  46. Gouws, C.A.; Georgousopoulou, E.; Mellor, D.D.; Naumovski, N. The effect of juicing methods on the phytochemical and antioxidant characteristics of the purple prickly pear (Opuntia ficus-indica)—Preliminary findings on juice and pomace. Beverages 2019, 5, 28. [Google Scholar] [CrossRef]
  47. Hęś, M.; Dziedzic, K.; Le Thanh-Blicharz, J.; Kmiecik, D.; Górecka, D. Antioxidant activity of true aloe (Aloe vera) extract in model systems. Nauka Przyr. Technol. 2016, 10, 53. [Google Scholar] [CrossRef]
  48. Dziedzic, K.; Górecka, D.; Szwengiel, A.; Sulewska, H.; Kreft, I.; Gujska, E.; Walkowiak, J. The Content of Dietary Fiber and Polyphenols in Morphological Parts of Buckwheat (Fagopyrum tataricum). Plant Foods Hum. Nutr. 2018, 73, 82–88. [Google Scholar] [CrossRef]
  49. Witkowska, A.; Borawska, M.; Lozowska, A.; Siwicka, J. Zawartość błonnika pokarmowego całkowitego w wybranych owocach [Total dietary fiber content in selected fruits]. Brom. Chem. Toks. 1998, 31, 115–118. (In Polish) [Google Scholar]
  50. Garcia-Amezquita, L.E.; Tejada-Ortigoza, V.; Serna-Saldivar, S.O.; Welti-Chanes, J. Dietary fiber concentrates from fruit and vegetable by-products: Processing, modification, and application as functional ingredients. Food Bioproc. Tech. 2018, 11, 1439–1463. [Google Scholar] [CrossRef]
  51. Grigelmo-Miguel, N.; Martín-Belloso, O. Comparison of dietary fibre from by-products of processing fruits and greens and from cereals. LWT—Food Sci. Technol. 1999, 32, 503–508. [Google Scholar] [CrossRef]
  52. Pereira-Netto, A.B. Tropical fruits as natural, exceptionally rich, sources of bioactive compounds. Int. J. Fruit Sci. 2018, 18, 231–242. [Google Scholar] [CrossRef]
  53. Moreno-Hernández, C.L.; Sáyago-Ayerdi, S.G.; García-Galindo, H.S.; Mata-Montes De Oca, M.; Montalvo-González, E. Effect of the application of 1-methylcyclopropene and wax emulsions on proximate analysis and some antioxidants of soursop (Annona muricata L.). Sci. World J. 2014, 2014, 896853. [Google Scholar] [CrossRef] [PubMed]
Agriculture 14 01790 g001
Figure 1. Correlation between the total phenolic content of P. pyraster and P. ×myloslavensis fruit extracts (mg GAE/g d.m.) (X-axis) and (a) DPPH, (b) the ABTS radical scavenging activity (mg Trolox/g s.m.), and (c) the FRAP reducing potential (mM Fe2+) (Y-axis).
Figure 1. Correlation between the total phenolic content of P. pyraster and P. ×myloslavensis fruit extracts (mg GAE/g d.m.) (X-axis) and (a) DPPH, (b) the ABTS radical scavenging activity (mg Trolox/g s.m.), and (c) the FRAP reducing potential (mM Fe2+) (Y-axis).
Agriculture 14 01790 g001
Table 1. Air temperature, precipitation, and soil characteristics of P. ×myloslavensis cultivation in 2021.
Table 1. Air temperature, precipitation, and soil characteristics of P. ×myloslavensis cultivation in 2021.
Month of MeasurementAir Temperature
(°C)		Precipitation
(mm)		Soil Characteristics
(mg dm−3 Soil)
January−0.680.2N-NH4 + N-NO312
February−0.733.0P96
March3.930.0K60
April6.165.0Ca2598
May12.066.4Mg155
June19.922.6pHH2O6.85
July20.719.4EC (mS cm−1)0.11
August17.557.2
September15.132.0
October9.634.8
November5.573.8
December−0.829.4
Average temperature9.0
Total precipitation 543.8
Table 2. Total content of phenolic compounds and the antioxidative activity of extracts from fruits of Pyrus pyraster and Pyrus ×myloslavensis.
Table 2. Total content of phenolic compounds and the antioxidative activity of extracts from fruits of Pyrus pyraster and Pyrus ×myloslavensis.
Extract from Pear FruitsTPC *
(mg GAE/g d.m.)		DPPH *
(mg Trolox/g d.m.)		ABTS *
(mg Trolox/g d.m.)		FRAP *
(mmol Fe2+/L)
P. pyraster197.15289.8111.3318.20
P. ×myloslavensis61.71134.390.690.60
* Student’s t-test; normal distribution with dependent estimation of variance (independent t-test by groups; normally distributed); statistical differences significant at p = 0.001.
Table 3. Contents of phenolic compounds and organic acids in extracts of Pyrus pyraster and Pyrus ×myloslavensis.
Table 3. Contents of phenolic compounds and organic acids in extracts of Pyrus pyraster and Pyrus ×myloslavensis.
P. pyrasterP. ×myloslavensis
Phenolic compounds (mg/g d.m.)
Chlorogenic acid0.1225 **0.0762 **
(−) Epicatechin0.0235 *0.0133 *
Quercetin 0.0193 ***0.0086 ***
Synapic acid0.0182 **0.0076 **
Vanillic acid0.0172 ***0.0016 ***
(+) Catechin 0.0100 *0.0075 *
Ferrulic acid0.0090 **0.0018 **
Organic acids (mg/g d.m.)
Citric acid0.0813 ***0.0440 ***
Maleic acid0.0127 **0.0067 **
Fumaric acid0.0023 ***0.0013 ***
Shikimic acid0.0016 *0.0008 *
* Student’s t-test; normal distribution with dependent estimation of variance (independent t-test by groups; normally distributed); p = 0.001; ** Normal distribution; Student’s t-test with independent estimation of variance (independent t-test by groups, with separate variance estimates); p = 0.001; *** Non-parametric statistic; Mann–Whitney test; p = 0.05.
Table 4. The effect of extracts from fruits of Pyrus pyraster and Pyrus ×myloslavensis on changes in the content of conjugated dienes in a linoleic acid emulsion (10−5 M).
Table 4. The effect of extracts from fruits of Pyrus pyraster and Pyrus ×myloslavensis on changes in the content of conjugated dienes in a linoleic acid emulsion (10−5 M).
Extract from Pear FruitsContent of Conjugated Dienes (10−5 M)
After Emulsion PreparationAfter 19 h Emulsion Incubation
P. pyraster 0.25%1.111.73 *
P. pyraster 0.5%1.021.65 ***
P. ×myloslavensis 0.25%0.854.53 *
P. ×myloslavensis 0.5%0.862.40 ***
Control1.005.59
* Student’s t-test; normal distribution with dependent estimation of variance (independent t-test by groups, normally distributed); p = 0.001; *** Non-parametric statistics; Mann–Whitney test; p = 0.05.
Table 5. Dietary fiber content in the fruits of Pyrus pyraster and Pyrus ×myloslavensis (g/100 g lyophilized pear sample).
Table 5. Dietary fiber content in the fruits of Pyrus pyraster and Pyrus ×myloslavensis (g/100 g lyophilized pear sample).
P. pyrasterP. ×myloslavensis
TDF36.45 ***24.74 ***
IDF32.49 ***20.86 ***
SDF3.75 *3.67 *
TDF—total dietary fiber; IDF—insoluble dietary fiber; SDF—soluble dietary fiber. * Student’s t-test; normal distribution with dependent estimation of variance (t-test independent by groups; normally distributed); p = 0.05; *** Non-parametric statistics; Mann–Whitney test; p > 0.05.
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Hęś, M.; Antkowiak, W.; Stuper-Szablewska, K.; Dziedzic, K.; Jessa, M.; Ratajczak, P. Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions. Agriculture 2024, 14, 1790. https://doi.org/10.3390/agriculture14101790

AMA Style

Hęś M, Antkowiak W, Stuper-Szablewska K, Dziedzic K, Jessa M, Ratajczak P. Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions. Agriculture. 2024; 14(10):1790. https://doi.org/10.3390/agriculture14101790

Chicago/Turabian Style

Hęś, Marzanna, Wojciech Antkowiak, Kinga Stuper-Szablewska, Krzysztof Dziedzic, Marta Jessa, and Paulina Ratajczak. 2024. "Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions" Agriculture 14, no. 10: 1790. https://doi.org/10.3390/agriculture14101790

APA Style

Hęś, M., Antkowiak, W., Stuper-Szablewska, K., Dziedzic, K., Jessa, M., & Ratajczak, P. (2024). Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions. Agriculture, 14(10), 1790. https://doi.org/10.3390/agriculture14101790

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