Phenolic compound characterisation and antiproliferative activity of “Annurca” apple, a southern Italian cultivar

A New Strategy Based on LC-Q TRAP-MS for Determining the Distribution of Polyphenols in Different Apple Varieties

Apples are a rich source of polyphenols in the human diet. However, the distribution of polyphenols in different apple varieties and tissues is still largely unclear. In this study, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) strategy was developed to reveal the spatial distribution of polyphenols in different apple tissues and varieties. A method based on multiple reaction monitoring (MRM)-enhanced product ion (EPI) was established in the information-dependent acquisition (IDA) mode for pseudo-target screening of major apple polyphenols. A total of 39 apple polyphenolic metabolites were finally identified. Qualitative and quantitative results showed that the variety and content of polyphenols in apple peels were higher than those of other tissues. In apple roots, stems, and leaves, the highest polyphenol variety and content were found in wild species, followed by cultivars and elite varieties. Dihydrochalcone substances, one kind of major apple polyphenols, were more abundant in apple roots, stems, and leaves. This strategy can be applied as a model for other agricultural products, in addition to revealing the distribution of polyphenols in different tissues of apples, which provides a theoretical basis for the utilization of polyphenol resources and variety selection.

Polyphenolics and Chemical Profiles of Domestic Norwegian Apple (Malus × domestica Borkh.) Cultivars

Using modern analytical techniques, a comprehensive study of the chemical composition of fruits from apple cultivars grown in Western Norway during 2019 and 2020 was done. Metals, sugars, organic acids, antioxidant tests, and polyphenol content have been observed. In all investigated samples, the most dominant sugars were glucose, fructose, and sucrose. Among 11 tested organic acids, the dominant was malic acid, followed by citric and maleic acid. The most common metal was potassium, followed by magnesium and zinc. The quantification of polyphenols showed that among the 11 quantified polyphenols, chlorogenic acid, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, quercetin, and phlorizin were the most abundant. A detailed study of the polyphenolic profile of nine investigated apple samples provided 30 identified polyphenolic compounds from the class of hydroxybenzoic and hydroxycinnamic acids, flavonoids, and dihydrochalcones. In addition to the identified 3-O-caffeoylquinic acid, its two isomers of 5-O-caffeoylquinic acid and three esters were also found. Present polyphenols of the tested apples provided significant data on the quality of Norwegian apples, and they contribute to the distinguishing of these apple samples.

Improving oxidative stability of foods with apple-derived polyphenols

Consumers demand healthy and natural food products. Thus, naturally derived antioxidants are emerging as a promising alternative to the use of present ingredients. Apples and apple derivative products (e.g., apple juice, apple cider, apple sauce, and others) are widely consumed throughout the world for a variety of different reasons and supply a large quantity of polyphenolic compounds. The extraction of polyphenolic compounds from apples and their incorporation into processed foods as naturally sourced ingredients could be a preferred alternative to commonly used commercial antioxidants that are used in many foods. In addition, they could have a positive impact on the environment and on the economy due to the utilization of byproducts generated during processing of apples, like apple pomace. In terms of the extraction procedures for the antioxidant compounds found in apples, the most efficient processes are methods that use ultrasound as the extraction tool. With this technique, greater yields are achieved, and less extraction time is required when compared with other, more conventional, extraction methods. However, parameters such as the extraction solvent, temperature during extraction, and extraction time must be suitably optimized in order to obtain the best performance and the highest antioxidant capacity. From an application standpoint, the use of apple-derived polyphenol extracts as a naturally derived food additive has documented applications for bread, meat, fish, cookies, and juices and there is evidence of increased antioxidant capacity, reduced rate of lipid oxidation, and increased storage time without compromising on sensory properties.

NMR Characterization of Ten Apple Cultivars from the Piedmont Region

The metabolite profile of ten traditional apple cultivars grown in the Piedmont region (Italy) was studied by means of nuclear magnetic resonance spectroscopy, identifying an overall number of 36 compounds. A more complete assignment of the proton nuclear magnetic resonance (¹H NMR) resonances from hydroalcoholic and organic apple extracts with respect to literature data was reported, identifying fructose tautomeric forms, galacturonic acid, γ-aminobutyric acid (GABA), p-coumaroyl moiety, phosphatidylcholine, and digalactosyldiacylglycerol. The chemical profile of each apple cultivar was defined by thorough quantitative NMR analysis of four sugars (fructose, glucose, sucrose, and xylose), nine organic acids (acetic, citric, formic, citramalic, lactic, malic, quinic, and galacturonic acids), six amino acids (alanine, asparagine, aspartate, GABA, isoleucine, and valine), rhamnitol, p-coumaroyl derivative, phloretin/phloridzin and choline, as well as β-sitosterol, fatty acid chains, phosphatidylcholine, and digalactosyldiacylglycerol. Finally, the application of PCA analysis allowed us to highlight possible differences/similarities. The Magnana cultivar showed the highest content of sugars, GABA, valine, isoleucine, and alanine. The Runsé cultivar was characterized by high amounts of organic acids, whereas the Gamba Fina cultivar showed a high content of chlorogenic acid. A significant amount of quinic acid was detected in the Carla cultivar. The knowledge of apple chemical profiles can be useful for industries interested in specific compounds for obtaining ingredients of food supplements and functional foods and for promoting apple valorization and preservation.

Profiling of Phenolic Compounds and Triterpene Acids of Twelve Apple (Malus domestica Borkh.) Cultivars

Apple (Malus domestica Borkh.), a popular and widely cultivated fruit world-wide, contains bioactive compounds responsible for their health benefits. Here we report the amounts of some bioactive compounds: two major triterpenes (oleanolic and ursolic acids) and polyphenols (phenolic acids, flavan-3-ols, flavonoids and t-resveratrol), together with bioactive properties of twelve apple cultivars measured by chromatographic and spectrophotometric methods. Significant variations were found comparing the bioactive potential of the investigated cultivars. High contents of phenolic acids were identified in the Montuan, Golden Delicious and Cretesc cultivars, while the most flavonoid dominant was the Richard cultivar. Starkrimson, Jonatan, Beliy Naliv and Richard cultivars present higher antioxidant capacity. Oleanolic acid ranged from 11 to 83 mg/g apple extract, while ursolic acid ranged from 55 to 436 mg/g apple extract, with higher amounts in Richard and Montuan cultivars. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed the discrimination of apple cultivars depending on polyphenolic and triterpene acids composition. Caffeic acid, gallic acid and epicatechin were identified as the main bioactive compounds in Starkrimson, Jonathan, Beliy Naliv and Richard cultivars, while ursolic and oleanolic acids were identified in high amounts in Richard, Montuan, Golden Delicious, Idared and Beliy Naliv apple cultivars. The results obtained in this study will contribute to the understanding of the bioactive composition of apples as well as the importance of their capitalization to obtain value-added products that promote human health.

Study of polyphenols, antioxidant capacity and minerals for the valorisation of ancient apple cultivars from Northeast Italy

Nutritional properties and quality of apple fruits can be related to presence of secondary metabolite contents such as phytochemicals and mineral elements. In this paper, eight polyphenols, four major minerals (Na, K, Mg, Ca), total phenolic content and antioxidant capacity were determined in fourteen ancient apple cultivars grown in Friuli Venezia Giulia (Northeast Italy) to highlight their nutraceutical properties. Both apple peel and pulp were examined separately and results were compared to those of six widespread commercial cultivars using principal component analysis. Ancient apples had much higher content in healthful compounds with respect to commercial varieties, particularly in the peel. Ancient cultivars showed a superior antioxidant capacity in peel (3- to 9- fold) and in pulp (2- to 5-fold) compared to commercial cultivars, with a good correlation with total phenolic content (R = 0.83 in peel and 0.69 in pulp). The polyphenols that mostly characterized the ancient apples pulp were catechins and flavonols. Regarding macro elements, K and Mg content were higher in ancient cultivars, while Na and Ca showed no significant differences. In the perspective of a sustainable economic and social development of local agricultural realities, these results contribute to the valorisation of ancient local apple cultivars as invaluable reservoir of genetic biodiversity to be promoted as functional food or exploited in breeding novel apple hybrids with high nutraceutical properties and better resistance to parasites.

Effects of Biostimulants on Annurca Fruit Quality and Potential Nutraceutical Compounds at Harvest and during Storage

The cultivar Annurca is an apple that is cultivated in southern Italy that undergoes a typical redding treatment and it is appreciated for organoleptic characteristics, high pulp firmness, and nutritional profile. In this study, the effects of three different biostimulants (Micro-algae (MA), Protein hydrolysate (PEP), and Macro-algae mixed with zinc and potassium (LG)), with foliar application, on the quality parameters of Annurca apple fruits at the harvest, after redding, and at +60 and +120 days of cold storage were analyzed: total soluble solids (TSS) content, total acidity (TA), pH, firmness flesh, and red coloration of epicarp. Additionally, the polyphenolic quali-quantitative profile of pulp and peel was analyzed by UHPLC-Q-Orbitrap HRMS and Folin-Ciocalteu and the antioxidant capacity with the methods 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric-reducing antioxidant capacity (FRAP). The results obtained suggest that biostimulants are involved in the regulation of the secondary metabolism of the treated plants, acting positively on the quality of the Annurca fruits and their nutritional value. Fruits treated with PEP have shown, during cold storage, a significantly higher content of total polyphenols in flesh and a higher concentration of phloretin xylo-glucoside and phloridzin (350.53 and 43.58 mg/kg dw respectively). MA treatment caused, at the same time, an enhancement of flavonols between 0.6–28% and showed the highest total polyphenol content in the peel after 60 and 120 days of cold storage, with 2696.048 and 2570.457 mg/kg dw, respectively. The long-term cold storage (120 days) satisfactorily maintained phenolic content of fruits deriving from MA and PEP application, in accordance with data that were obtained for peel, showed an increase of 7.8 and 5.8%, respectively, when compared to the fruits cold stored for 60 days. This study represents the first detailed research on the use of different types of biostimulants on the quality of the Annurca apple from harvest to storage.

Comprehensive characterization of phytochemicals and biological activities of the Italian ancient apple 'Mela Rosa dei Monti Sibillini'

This study was carried out to characterize extracts from nine samples of the apple 'Mela Rosa dei Monti Sibillini' (MR) and to assess the antioxidant and anti-inflammatory activities. The extracts were analysed by High Performance Liquid Chromatography coupled with photodiode array detector and mass spectrometry (HPLC-DAD-MS) for 20 phytochemicals. The extracts from the lyophilized material (ELM) were richer in polyphenolic compounds than the dried ones (EDM). The MR extracts contained noteworthy amounts of the investigated analytes compared to one sample of the commercial varieties Annurca, Golden Delicious and Granny Smith used as reference. Principal component analysis (PCA) revealed that the part of the fruit seems to have a significant influence on the chemical composition of the final extract; thus, the peel extracts exhibited higher levels of phenolic compounds, especially epicatechin, procyanidin B2 and phloridzin, and triterpenes than the pulp ones. In general, the lyophilized material showed higher antioxidant activity than the dried material. The strong antioxidant capacity of the MR has also been revealed by the DPPH, ABTS, FRAP and Folin-Ciocalteau assays. The ELM of MR significantly reduced reactive oxygen species in lipopolysaccharide (LPS)-activated mouse brain microglia cells (BV-2 cells). Real-time polymerase chain reaction (RT-PCR) analysis demonstrated that the EDM and ELM of MR were effective in reducing pro-inflammatory cytokines and enzymes in BV-2 and peripheral blood mononuclear cells (PBMC). These results contribute to the exploitation of this ancient variety as a source of nutraceuticals.

Metabolite Profiling and Antioxidant Activity of 10 New Early- to Mid-Season Apple Cultivars and 14 Traditional Cultivars

Early- to mid-season apple cultivars have recently been developed in response to global warming; however, their metabolite compositions remain unclear. Herein, metabolites, such as free sugars, and organic acids and antioxidant activity were determined in 10 new and 14 traditional apple cultivars. Additionally, the phenolic profiles of the apple pulp and peel were characterized by high-resolution mass spectrometry. Major phenolic compounds in apples varied depending on the cultivar and tissue (i.e., peel or pulp). Among the new apple cultivars, Decobell and Tinkerbell, showed high antioxidant activity and contained higher phenolic compound content than other cultivars in the peel and pulp, respectively. Honggeum showed high phenolic content with similar sugar to acid ratio compared to popular traditional cultivars. In addition to antioxidant phenolic contents, metabolite profile information can be used to select apple cultivars for various purposes. For example, Indo can be selected for sweet apple taste because of its higher sugar to acid ratio. This information can be used to select apple cultivars for various purposes. For example, Decobell peel could be used as sources of food supplements and food additives, and Tinkerbell pulp can be utilized for apple juice making according to its metabolite profile.

Simultaneous extraction and separation of bioactive compounds from apple pomace using pressurized liquids coupled on-line with solid-phase extraction

The objective of this work was the development of an on-line extraction/fractionation method based on the coupling of pressurized liquid extraction and solid-phase extraction for the separation of phenolic compounds from apple pomace. Several variables of the process were evaluated, including the amount of water of the first stage (0-120 mL), temperature (60-80 °C), solid-phase extraction adsorbent (Sepra, Isolute, Strata X and Oasis) and activation/elution solvent (methanol and ethanol). The best results were observed with the adsorbent Sepra. The temperature had a small effect on recovery, but significant differences were observed for phlorizin and a quercetin derivative. Results indicate that ethanol can be used to replace methanol as an activation, extraction/elution solvent. While using mostly green solvents (water, ethanol, and a small amount of methanol that could be reused), the developed method produced higher or similar yields of acids (2.85 ± 0.19 mg/g) and flavonoids (0.97 ± 0.11 mg/g) than conventional methods.

The effects and associations of whole-apple intake on diverse cardiovascular risk factors. A narrative review

Apples are among the world's most consumed fruits. However, while the impact of whole-apple intake on cardiovascular disease (CVD) remains unknown. This narrative review summarizes a novel integrated view of whole-apple intake, CVD risk association (through observational studies; OSs), and the effects on CVD risk factors (randomized trials; RTs). In 8 OSs, whole-apple intake was associated with a reduced risk of CVD mortality, ischemic heart disease mortality, stroke mortality, all-cause mortality, and severe abdominal aortic calcification, as well as with lower C-reactive protein (CRP) concentrations. In 8 RTs, whole-apple consumption reduced total cholesterol, low-density lipoprotein cholesterol, systolic blood pressure, pulse pressure, and plasma inflammatory cytokines, and noticeably reduced CRP, whereas it increased high-density lipoprotein cholesterol (HDLc) and improved endothelial function. Thus, consuming between 100 and 150 g/day of whole apples is associated with a lower CVD risk and decreases in blood pressure, pulse pressure, total cholesterol, low-density lipoprotein cholesterol, and inflammation status as well as with increases in HDLc and endothelial function. These results, support the regular consumption of whole apples as an aid in the prevention of CVD.

A comparison of the chemical composition and antioxidant activity of several new early- to mid-season apple cultivars for a warmer climate with traditional cultivars

BACKGROUND

New early- to mid-season apple cultivars are being developed to help address warmer growing seasons due to climate change. Free sugars, organic acids, total phenolic content, total flavonoid content, antioxidant activity and phenolic composition were determined in the pulp and peel of six new and six traditional apple cultivars. In addition, the phenolic profiles of apple peels were characterized using high-resolution mass spectrometry. Forty-eight polyphenol compounds were identified, by accurate mass, in apple peel.

RESULTS

Compared to Fuji apples, a new apple cultivar, Decobell, contained 2.6- and 1.4-fold higher levels of the sum of individual polyphenol levels in the peel and the pulp, respectively. Decobell apples showed similar sugar-to-acid ratio (0.27) to Fuji apples (0.25).

CONCLUSIONS

The results indicate that the Decobell cultivar could have the best quality characteristics in terms of sugar-to-acid ratios and health-promoting activities due to the phenolic profiles. © 2019 Society of Chemical Industry.

Characterization of nutrients, polyphenols and volatile components of the ancient apple cultivar 'Mela Rosa Dei Monti Sibillini' from Marche region, central Italy

In the present work, we reported for the first time a comprehensive study on the phytonutrients, that is, natural compounds able to provide benefits to health, found in an ancient apple variety cultivated in orchards of the Sibillini Mountains, central Italy, known as Mela Rosa dei Monti Sibillini. This fruit has recently been promoted by authorities and local institutions as a typical food of the Marche Region. For the purpose, analysis of its nutrients, phenolics, triterpenes and volatile components as well as a morpho-anatomical study was carried out in order to give an added value for its consumption and promotion at regional and national level. ICP-MS, HPLC-MSⁿ and GC-MS analyses were useful techniques for giving a typical fingerprint to this apple, consisting in a high content of K and B, quercetin derivatives as the main phenolic compounds and carboxylic esters, aldehydes, alcohols and (E,E)-α-farnesene as the main key odorants.

Triterpene Acid and Phenolics from Ancient Apples of Friuli Venezia Giulia as Nutraceutical Ingredients: LC-MS Study and In Vitro Activities

Triterpene acid and phenolic constituents from nine ancient varieties of apple (Malus domestica) fruits cultivated in Fanna, Friuli Venezia Giulia region, northeast Italy, were analyzed and compared with four commercial apples ('Golden Delicious', 'Red Delicious', 'Granny Smith' and 'Royal Gala'). Total phenolic and flavonoid contents were measured by spectrophotometric assays. The quali-quantitative fingerprint of secondary metabolites including triterpene acid was obtained by LC-DAD-(ESI)-MS and LC-(APCI)-MS, respectively. Based on the two LC-MS datasets, multivariate analysis was used to compare the composition of ancient fruit varieties with those of four commercial apples. Significant differences related mainly to the pattern of triterpene acids were found. Pomolic, euscaphyc, maslinic and ursolic acids are the most abundant triterpene in ancient varieties pulps and peels, while ursolic and oleanolic acids were prevalent in the commercial fruits. Also, the content of the phenolic compounds phloretin-2-O-xyloglucoside and quercetin-3-O-arabinoside was greater in ancient apple varieties. The antioxidant (radical scavenging, reducing power, metal chelating and phosphomolybdenum assays) and enzyme inhibitory effects (against cholinesterase, tyrosinase, amylase and glucosidase) of the samples were investigated in vitro. Antioxidant assays showed that the peels were more active than pulps. However, all the samples exhibited similar enzyme inhibitory effects. Ancient Friuli Venezia Giulia apple cultivars can be a source of chlorogenic acid and various triterpene acids, which are known for their potential anti-inflammatory activity and beneficial effects on lipid and glucose metabolism. Our results make these ancient varieties suitable for the development of new nutraceutical ingredients.

Development of Health Products from Natural Sources

BioActive Compounds (BACs) recovered from food or food by-product matrices are useful in maintaining well being, enhancing human health, and modulating immune function to prevent or to treat chronic diseases. They are also generally seen by final consumers as safe, non-toxic and environment-friendly. Despite the complex process of production, chemical characterization, and assessment of health effects, BACs must also be manufactured in stable and bioactive ingredients to be used in pharmaceutical, food and nutraceutical industry. Generally, vegetable derivatives occur as sticky raw materials with pervasive smell and displeasing flavor. Also, they show critical water solubility and dramatic stability behavior over time, involving practical difficulties for industrial use. Therefore, the development of novel functional health products from natural sources requires the design of a suitable formulation to delivery BACs at the site of action, preserve stability during processing and storage, slow down the degradation processes, mask lousy tasting or smell, and increase the bioavailability, while maintaining the BACs functionality. The present review focuses on human health benefits, BACs composition, and innovative technologies or formulation approaches of natural ingredients from some selected foods and by-products from industrial food transformations.

Targeted Metabolic Profiling Indicates Apple Rootstock Genotype-Specific Differences in Primary and Secondary Metabolite Production and Validate Quantitative Contribution From Vegetative Growth

Previous reports regarding rhizodeposits from apple roots are limited, and complicated by microbes, which readily colonize root systems and contribute to modify rhizodeposit metabolite composition. This study delineates methods for collection of apple rhizodeposits under axenic conditions, indicates rootstock genotype-specific differences and validates the contributions of vegetative activity to rhizodeposit quantity. Primary and phenolic rhizodeposit metabolites collected from two apple rootstock genotypes, G935 and M26, were delineated 2 months after root initiation by utilizing gas chromatography/liquid chromatography-mass spectrometry (GC/LC-MS), respectively. Twenty-one identified phenolic compounds and 29 sugars, organic acids, and amino acids, as well as compounds tentatively identified as triterpenoids were present in the rhizodeposits. When adjusted for whole plant mass, hexose, erythrose, galactose, phloridzin, kaempferol-3-glucoside, as well as glycerol, and glyceric acid differed between the genotypes. Phloridzin, phloretin, epicatechin, 4-hydroxybenzoic acid, and chlorogenic acid were among the phenolic compounds found in higher relative concentration in rhizodeposits, as assessed by LC-MS. Among primary metabolites assessed by GC-MS, amino acids, organic acids, and sugar alcohols found in relatively higher concentration in the rhizodeposits included L-asparagine, L-cysteine, malic acid, succinic acid, and sorbitol. In addition, putative ursane triterprenoids, identified based on accurate mass comparison to previously reported triterpenoids from apple peel, were present in rhizodeposits in high abundance relative to phenolic compounds assessed via the same extraction/instrumental method. Validation of metabolite production to tree vegetative activity was conducted using a separate set of micropropagated trees (genotype MM106) which were treated with a toxic volatile compound (butyrolactone) to inhibit activity/kill leaves and vegetative growth. This treatment resulted in a reduction of total collected rhizodeposits relative to an untreated control, indicating active vegetative growth contributes to rhizodeposit metabolites. Culture-based assays indicated an absence of bacterial or fungal endophytes in roots of micropropagated G935 and M26 plants. However, the use of fungi-specific primers in qPCR indicated the presence of fungal DNA in 30% of the samples, thus the contribution of endophytes to rhizodeposits cannot be fully eliminated. This study provides fundamental information for continued research and application of rhizosphere ecology driven by apple rootstock genotype specific rhizodeposition.

WNT Inhibitory Activity of Malus Pumila miller cv Annurca and Malus domestica cv Limoncella Apple Extracts on Human Colon-Rectal Cells Carrying Familial Adenomatous Polyposis Mutations

Inhibitors of the Wingless-related Integration site (WNT)/β-catenin pathway have recently been under consideration as potential chemopreventive agents against Familial Adenomatous Polyposis (FAP). This autosomal-dominant syndrome is caused by germline mutations in the gene coding for the protein APC and leads to hyperactivation of the WNT/β-catenin signaling pathway, uncontrolled intestinal cell proliferation and formation of adenocarcinomas. The aim of the present work was to: (i) test, on in vitro cultures of cells carrying FAP mutations and on ex vivo biopsies of FAP patients, the WNT inhibitory activity of extracts from two common southern Italian apples, Malus pumila Miller cv. 'Annurca' and Malus domestica cv 'Limoncella'; (ii) identify the mechanisms underpinning their activities and; (iii) evaluate their potency upon gastrointestinal digestion. We here show that both Annurca and Limoncella apple extracts act as WNT inhibitors, mostly thanks to their polyphenolic contents. They inhibit the pathway in colon cells carrying FAP mutations with active dilutions falling in ranges close to consumer-relevant concentrations. Food-grade manufacturing of apple extracts increases their WNT inhibitory activity as result of the conversion of quercetin glycosides into the aglycone quercetin, a potent WNT inhibitor absent in the fresh fruit extract. However, in vitro simulated gastrointestinal digestion severely affected WNT inhibitory activity of apple extracts, as result of a loss of polyphenols. In conclusion, our results show that apple extracts inhibit the WNT pathway in colon cells carrying FAP mutations and represent a potential nutraceutical alternative for the treatment of this pathology. Enteric coating is advisable to preserve the activity of the extracts in the colon-rectal section of the digestive tract.

Polyphenolic compounds from Malus hupehensis and their free radical scavenging effects

One new 4-chromanone glycoside, 5-O-β-d-glucopyranoside-4-chromanone (1), together with 21 known polyphenols, was isolated from the leaves of Malus hupehensis. Their structures were elucidated on the basis of extensive spectroscopic methods including NMR (1D and 2D), mass (ESIMS and HRESIMS), IR, and by comparison with the data reported in the literature. Some of the isolated compounds were screened for antioxidant activity. Compounds 18 and 14 exhibited significant antioxidant activities with SC₅₀ values 2.73 and 2.91 μg/mL, respectively, while 17, 19, 11, 7, 20, 22, 12 and 13 exhibited moderate activities with SC₅₀ values ranging from 5.24-11.86 μg/mL. The HPLC fingerprint profiles of the leaves and fruits extracts were also analysed, which showed that the constituents were almost the same in both the extracts except for the content of phlorizin which was present in higher amount in the leaves.

Evaluation of different training systems on Annurca apple fruits revealed by agronomical, qualitative and NMR-based metabolomic approaches

Nine different training systems for "Annurca Rossa del Sud" apple fruits, including oblique palmette, free palmette, V-shaped, Tatura trellis, Bibaum®, modified Bibaum®, triple leader, slender spindle and Solaxe, were evaluated based on agronomic, qualitative and metabolomic traits. Fruits were analysed at harvest and after the reddening process. The slender spindle training system showed the highest cumulative efficiency yield compared to the others. Furthermore, an increase in the content of bioactive compounds in flesh and fruit peels was observed after the reddening process and was influenced by the different training systems. The metabolic variations in apple peel were measured and analysed. Changes in the metabolome highlight the influence of different training systems on apple quality. This multidisciplinary study expands our knowledge of the influence of training systems on a typical Italian apple cultivar.

A theoretical study on predicted protein targets of apple polyphenols and possible mechanisms of chemoprevention in colorectal cancer

We investigated the potential role of apple phenolic compounds in human pathologies by integrating chemical characterization of phenolic compounds in three apple varieties, computational approaches to identify potential protein targets of the compounds, bioinformatics analyses on data from public archive of gene expression data, and functional analyses to hypothesize the effects of the selected compounds in molecular pathways. Starting by the analytic characterization of phenolic compounds in three apple varieties, i.e. Annurca, Red Delicious, and Golden Delicious, we used computational approaches to verify by reverse docking the potential protein targets of the identified compounds. Direct docking validation of the potential protein-ligand interactions has generated a short list of human proteins potentially bound by the apple phenolic compounds. By considering the known chemo-preventive role of apple antioxidants' extracts against some human pathologies, we performed a functional analysis by comparison with experimental gene expression data and interaction networks, obtained from public repositories. The results suggest the hypothesis that chemo-preventive effects of apple extracts in human pathologies, in particular for colorectal cancer, may be the interference with the activity of nucleotide metabolism and methylation enzymes, similarly to some classes of anticancer drugs.

Apple phenolics as nutraceuticals: assessment, analysis and application

Humankind is presently engulfed by convenience quench, modern life style and urbanized diet system leading to progression in array of health disorders. The past decade confronted cardiometabolic disorder (21.8 %), lower respiratory and chronic obstructive lung disease (12.5 %) as the major causes of death world over. In anticipation, scientific communities' have demonstrated the role of healthy diets, especially those rich in fruits and vegetables, for management of such health related issues. These horticultural  crops are considered as a good source of polyphenols such as dihydrochalcones, flavanols, flavonols, anthocyanins and phenolic acids. The present article reviews the efforts made to assess the potential of apple phenolic compounds present in fresh fruits, leaves, bark and pomace as dietary polyphenols. Considering the positive impact of such phytochemicals on human health, various nutraceuticals, dietary supplements and phenolic-rich food products are presently available on market shelves. On analytical front, improved instrumentation based on liquid chromatography (HPLC, UPLC, LC/MS/MS) have made the assessment of phenolics more rapid and reliable. Thus, owing to the emergent interest in natural compounds, it is pertinent to discuss the latest significant research findings on therapeutic aspects along with probable metabolic mechanisms of dietary polyphenols found in apples and their implications on human health.

Polyphenols from pinecones of Pinus koraiensis induce apoptosis in colon cancer cells through the activation of caspase in vitro

The present study reports the antitumor effects of PPP-40 (the purified polyphenols from P. koraiensis pinecones by 40% ethanol) on LOVO cells and revealed its antitumor mechanism, which involved the apoptosis of cells associated with the activation of the caspase pathway.

Inhibition of Breast Cancer Cell Proliferation and In Vitro Tumorigenesis by a New Red Apple Cultivar

PURPOSE

The aim of this study was to evaluate the antiproliferative activity in breast cancer cells and the inhibition of tumorigenesis in pre-neoplastic cells of a new apple cultivar with reddish pulp, called the Pelingo apple.

METHODS

The antiproliferative activity was evaluated in MCF-7 and MDA-MB-231 human breast cancer cells. The inhibition of tumorigenesis was performed in JB6 promotion-sensitive (P+) cells.

RESULTS

Results showed that Pelingo apple juice is characterized by a very high polyphenol content and strongly inhibited breast cancer cell proliferation. Its antiproliferative activity was found to be higher than the other five apple juices tested. Pelingo juice induced cell accumulation in the G2/M phase of the cell cycle and autophagy through overexpression of p21, inhibition of extracellular signal-regulated kinases 1/2 (ERK1/2) activity and an increase in lipidated microtubule-associated protein-1 light chain-3 beta (LC3B). Remarkably, Pelingo juice inhibited the 12-o-tetra-decanoyl-phorbol-13-acetate (TPA)-induced tumorigenesis of JB6 P+ cells, suppressing colony formation in semi-solid medium and TPA-induced ERK1/2 phosphorylation.

CONCLUSIONS

Our data indicate that the Pelingo apple is rich in food components that can markedly inhibit in vitro tumorigenesis and growth of human breast cancer cells and could provide natural bioactive non-nutrient compounds, with potential chemopreventive activity.

Optimization of Purification, Identification and Evaluation of the in Vitro Antitumor Activity of Polyphenols from Pinus Koraiensis Pinecones

In this study, an efficient purification method for the polyphenols of Pinus koraiensis pinecone (PPP) has been developed. AB-8 resin was verified to offer good adsorption and desorption ratio for PPP. Response surface methodology (RSM) indicated that the optimized purification parameters for PPP were 1.70 mg GAE/mL phenolic sample concentration, 22.00 mL sample volume, and 63.00% ethanol concentration. Under these conditions, the experimental purity of PPP was 27.93 ± 0.14% (n = 3), which matched well with the predicted purity of 28.17%. Next, the antiproliferative effects of PPP on seven cancer cell lines, including A375 (human skin melanoma cancer cell line), A549 (human lung cancer cell line), SH-SY5Y (human neuroblastoma cell line), LOVO (human colon cancer stem cell line), MCF-7 (human breast cancer cell line), HeLa (human cervical cancer line), and HT29 (human colon cancer line), were examined by MTT assays. The results indicated that PPP had the highest capacity for inhibiting LOVO cells growth with an EC50 value of 0.317 ± 0.0476 mg/mL. Finally, Ultra-high performance liquid chromatography- tandem mass spectrometry (UPLC-MS) was used to tentatively identify twenty-four peaks in the purified PPP, of which five representative peaks were identified as catechin, methyl quercetin, o-vanillin, luteolin and coronaric acid. Our results demonstrate that Pinus koraiensis pinecone is a readily available source of polyphenols, and the purified PPP could be a promising natural antitumor agent for applications in functional foods.

Detailed polyphenolic profiling of Annurca apple (M. pumila Miller cv Annurca) by a combination of RP-UHPLC and HILIC, both hyphenated to IT-TOF mass spectrometry

Annurca apple, a Southern Italian cultivar, possesses not only a particular taste and flavor, different from other types of apple, but also several healthy properties. With the aim to thoroughly elucidate the polyphenolic profile of this variety, listed as Protected Geographical Indication product, an extensive qualitative profiling of Annurca apple polyphenolic peel extract was carried out, by employing a combination of ultra high performance reversed phase (RP-UHPLC) and hydrophilic liquid chromatography (HILIC) coupled to ion trap-time of flight (IT-TOF) mass spectrometry. A total of 63 compounds were tentatively identified, 25 of which not reported in Annurca apple extract so far. Furthermore, thanks to the different selectivity obtained with the HILIC, in combination with accurate mass measurements, an improved separation and detection of procyanidins, was obtained. Moreover, the obtained profiles were compared with those of a conventional variety, such as Red Delicious (RD), highlighting their differences. This work contributes to increase the knowledge about the polyphenolic fingerprint of this typical apple variety.

Application of an Optimized HPLC Method for the Detection of Various Phenolic Compounds in Apples from Lithuanian Cultivars

A specific analytical procedure including sample preparation and HPLC analysis was developed and validated for the detection of phenolic compounds in the samples of different apples from popular Lithuanian cultivars “Aldas,” “Auksis,” “Ligol,” and “Šampion.” The conditions for phenol extraction were optimized: the solvent of the extraction was 70% (v/v) ethanol, and the extraction was performed in an ultrasound bath for 20 min at the temperature of 40°C. The HPLC mobile phase consisted of 2% (v/v) acetic acid in water and 100% (v/v) acetonitrile. Using the HPLC technique, 11 analytes were identified, and their specificity was confirmed: procyanidin B1, (+)-catechin, chlorogenic acid, procyanidin B2, (−)-epicatechin, rutin, hyperoside, isoquercitrin, avicularin, quercitrin, and phloridzin. Chlorogenic acid was the major component in “Aldas,” “Auksis,” and “Ligol” and procyanidin B2 in “Šampion.” Hyperoside and avicularin were the dominant compounds of all the identified quercetin derivatives in “Aldas” and “Auksis;” hyperoside in “Šampion;” and quercitrin in “Ligol.” The total content of phenolic compounds varied from 1641.0 ± 47.9 μg/g (cv. “Ligol”) to 4291.3 ± 154.2 μg/g (cv. “Aldas”).

In vitro bioaccessibility, bioavailability and plasma protein interaction of polyphenols from Annurca apple (M. pumila Miller cv Annurca)

The in vitro bioaccessibility, bioavailability and plasma protein interaction of polyphenols from Annurca apple and other conventional cultivars were evaluated. Salivary digestion concentrated into the medium 27-35% of native apple polyphenols, suggesting the potential bioavailability through the oral mucosal epithelium of significant amounts of bioactive compounds that could be gastric sensitive and/or poorly absorbed in the intestine. Annurca flesh revealed the highest content and provided the best intestinal bioaccessibility and bioavailability of oligomeric procyanidins among all of the apple peel and flesh tested. Since 49.4% of native procyanidins were not absorbed, they are expected to accumulate in the intestinal lumen where a potential inhibition capacity of cellular cholesterol uptake could be assumed. The permeated procyanidins (6.7% of their native pattern, 12.0% of intestinal procyanidins) significantly bound (58.7%) to plasma HDLs, suggesting a major role in cholesterol metabolism. Our results would indicate Annurca apple and its potential nutraceuticals as effective in the regulation of plasma cholesterol levels.

Profiling of phenolic compounds from different apple varieties using comprehensive two-dimensional liquid chromatography

An innovative analytical approach based on the use of comprehensive two-dimensional liquid chromatography (LC×LC) is applied to obtain the profiling of phenolic compounds in different apple varieties. The method combines the use of hydrophilic interaction liquid chromatography in the first dimension and a reversed phase separation in the second dimension, as well as the use of diode array and mass spectrometry detection. Using this methodology is possible to obtain in less than 50 min the complete profiling of phenolic compounds in a complex food matrix such as apple. In fact, different flavan-3-ols including procyanidin oligomers with degree of polymerization up to 8, as well as several dihydrochalcones, flavonols and a phenolic acid are separated and tentatively identified in these samples in a single run. Besides, the total phenols and total procyanidins amounts were determined using two in vitro assays. Reinette apples presented the highest content on total phenols (6.46 mg galic acid equiv./g dry matter) whereas Granny Smith apples were the richest on total procyanidins (0.73 mg epicatechin equiv./g dry matter). This work shows the great potential of LC×LC for phenolic compounds profiling in complex food samples.

Nutraceutical potential of polyphenolic fractions from Annurca apple (M. pumila Miller cv Annurca)

The capacities of polyphenolic extracts from Annurca apple peel and flesh to inhibit the glucose and cholesterol uptake by HepG2 cells were evaluated, and compared with those of other conventional cultivars, such as Red Delicious (RD), Pink Lady (PL), Fuji (F) and Golden Delicious (GD). RD peels exhibited the best hypoglycaemic effects, while Annurca flesh appeared the most active in reducing cell cholesterol uptake among the cultivars tested. The influence of the apple polyphenolic extracts on the cell proliferation and oxidative stress was also evaluated. Particularly, RD, Annurca and PL peels decreased proliferation by a 62.5%, 48.0% and 37.5%, respectively, probably due to their prooxidant capacity. Conversely, flesh extracts appeared more protective of cells than peels: Annurca and RD, particularly, proved to be able of increasing proliferation by a 32.2% and 11.1%, respectively, probably due to their capacity of reducing cell physiological radical levels of a 33.3% and 19.9%, respectively.

Phenolic composition and free radical scavenging activity of different apple varieties in relation to the cultivar, tissue type and storage

The aim of this research was to evaluate the influence of genotype, tissue type and cold storage on the bioactive compounds content and on the antiradical activity (AA) of different apple cultivars (Golden cl. B, Fuji cl. Kiku8, Braeburn cl. Hillwell). The content of analysed phyto-compounds depended on the clone, on the part of fruit, and to a minor extent, on the storage. For EC(50) data, the cultivar represented the main source of variation and the interaction with the type of tissue, was significant. The AA of apples, measured by means of the DPPH test, was highly correlated to the flavan-3-ols content, which represents a good predictor of the apple antiradical power. The new Braeburn's clone, the Hillwell, had the worst AA related to a minor phyto-chemical content. Also, its phenolic content was dramatically reduced after cold storage (flesh: -50%; peels: -20%; p<0.05). Obtained results underlined the key role of the genotype on the content of the nutraceutical power of apples, which is important to improve their quality and consumption benefits, suggesting to the breeders to pay more attention to the potential healthy compounds in the development of new hybrids.