Activity and concentration of polyphenolic antioxidants in apple: effect of cultivar, harvest year, and storage conditions

Determination of Polyphenolic Profile of Apple Pomace (Malus domestica Golden Delicious Variety) by HPLC-MS

Apple (Malus domestica Borkh) is an appreciated source of polyphenols. Phenolic compounds are known as natural antioxidants and have a wide range of applications in different industries. Apple pomace has the potential of being an alternative source of polyphenols. To determine the polyphenolic profile of apple pomace, samples from the skin at two different stages of ripening were extracted with 80-20% EtOH-water/acetic acid 5% (S1) and 20-80% EtOH-water/acetic acid 5% (S2) in order to determine the solvent system. Ripe skins extracted with S1 showed a higher total polyphenol content or TPC (1.21 g of polyphenols per 100 g of fresh weight (FW)) than unripe apple skin, being the most effective system tested and a mean degree of polymerization of 2.47. Commercial apple pomace was extracted with S1, resulting in a TPC of 0.5615 ± 0.007 g of polyphenols per 100 g of FW. Meanwhile, the RP-HPLC-MS analysis led to the tentative identification of several polyphenolic compounds.

Unveiling Apple Diversity: The Quality of Juice Produced from Old vs. Commercial Apple Cultivars

This research is focused on comparing the compositions of juice produced from old and commercially grown apple cultivars. We examined factors such as pH, total acids, soluble dry matter, polyphenol profile, and antioxidant activity, which impact the attributes, safety, shelf life, and nutritional value of the juice. Our analysis revealed differences between these two groups of cultivars. For instance, pH values ranged from 3.04 (in 'Bobovec') to 3.69 (in 'Fuji'). The proportions of acids varied from 0.07 g/100 mL (in 'Fuji') to 0.19 g/100 mL (in 'Wagener'). Soluble dry matter content ranged from 14.10% (in 'Fuji') to 18.50% (in 'Kraljevčica'). We also observed variations in sugar content and composition among cultivars; for example, sucrose levels varied from 16.11 g/L ('Fuji') to 39.36 g/L ('Golden Delicious). Glucose levels ranged from 4.95 g/L ('Jonagold') to 19.18 g/L ('Fuji'), while fructose levels spanned from 50.78 g/L ('Austrougarka') to 427.97 g/L ('Ilzer Rosenapfel'). Furthermore, old apple cultivars exhibited higher concentrations of phenols and flavonoids compared to commercial ones; we also noted significant variations in flavonol levels among different cultivars. The 'Wagener' and 'Božićnica' apple varieties had levels of myricetin measuring 0.53 and 0.52 µg/mL, respectively. On the other hand, 'Bobovec' stood out for its content of procyanidin B2 with a concentration of 422.61 µg/mL. When examining non-flavonoid compounds, it was found that old apple cultivars had higher concentrations of gallic acid, trans-ferulic acid, and chlorogenic acid. However, commercial cultivars showed dominance in caffeic and p-coumaric. Comparisons of antioxidant capacity using DPPH and ABTS assays clearly demonstrated the superiority of old apple cultivars. Overall, this study highlights the importance of utilizing apple cultivars for juice production. Their distinct compositions and higher antioxidant capacities contribute to potential health benefits. Preserving these cultivars for enhanced juice quality and nutritional value is encouraged. Further research could explore cultivation practices' impact on composition and health benefits.

The Influence of Antioxidant Plant Extracts on the Oxidation of O/W Emulsions

The demand for natural cosmetics has steadily increased in recent years. However, challenges occur especially in quality preservation regarding oxidative spoilage of natural cosmetic products, as the use of synthetic preservatives and antioxidants is limited. Therefore, it is important to find nature-based ingredients to ensure shelf life in natural cosmetic formulations. As a result, potential is seen in the use of plant-based antioxidant extracts. The aim of this work was to determine the suitability of the method combination by measuring the antioxidant activity, oxygen concentration, and volatile oxidation products via gas chromatography (hexanal) for the characterization of the influence of some plant extracts on the oxidative stability of natural cosmetic emulsions. Plant extracts of Riesling (Vitis vinifera) pomace, apple (Malus domestica) pomace, coffee (Coffea arabica) grounds, cocoa (Theobroma cacao) husk, and coffee (Coffea arabica) powder extract were incorporated in stable O/W emulsion formulations, while an emulsion without extract functioned as blank. Afterwards, the emulsions were subjected to 3-month accelerated storage tests with and without light exposure. Their oxygen uptake was investigated, and headspace gas chromatography measurements were performed to detect the fatty acid oxidation products formed during oxidative processes in the samples. The results showed that all emulsion samples under light exposure had a higher oxygen uptake and an increase in the characteristic fatty acid oxidation products compared with those stored under light exclusion. However, differences in oxygen uptake under light exposure were observed depending on the plant extract. Therefore, for O/W emulsions, the daily oxygen consumption rate correlated exponentially with the antioxidant activity, and the hexanal concentration correlated linearly with the daily oxygen consumption rate.

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.

Comparative Insights into the Antimicrobial, Antioxidant, and Nutritional Potential of the Solanum nigrum Complex

Solanum nigrum is a traditional medicinal plant renowned as a cure for many diseases due to the presence of bioactive compounds. The Solanum nigrum complex refers to a group of more than 30 closely related but morphologically distinct taxa. Five indigenous taxa of this complex were investigated for their medicinal potential by using methanolic extracts. The efficacy of each plant was different for each of the seven bacteria studied. On comparing the MIC values, S. americanum was found to be most potent against Bacillus licheniformis (34 µg/mL), S. chenopodioides against Escherichia coli (78 µg/mL), S. nigrum against Bacillus licheniformis (49 µg/mL) and Escherichia coli (49 µg/mL), S. retroflexum against Escherichia coli (30 µg/mL), and S. villosum against Proteus mirabilis (45 µg/mL). The extracts were also subjected to six antioxidant assays. Moderate scavenging activity was observed by all plants in the DPPH free radical assay, but S. chenopodioides was the most effective. The total phenolic contents of the five plants were comparable, but the gallic acid equivalents of S. americanum and S. nigrum were the highest (26.58 mg/100 g GAE). The highest Trolox equivalent antioxidant capacity was observed for S. retroflexum, with the ABTS assay giving a TEAC value of 33.88 mM/100 g of dry weight. Metal-chelating activity against Fe2+ was observed to be highest for S. chenopodioides (70.37%). The FRAP value of S. nigrum was the highest (8.5 mM FeSO4·7H2O) among all taxa. The lipid peroxidation trend was very similar for all five samples. The results suggest the specified medicinal use of different members of the Solanum nigrum complex, which will also have significant nutritional value.

Occurrence of Patulin and Polyphenol Profile of Croatian Traditional and Conventional Apple Cultivars during Storage

Apples and apple-based products are among the most consumed fruits around the world. However, they are susceptible to infection with the fungi Penicilium expansum. In addition to the reduction of apple quality, secondary metabolism of this fungus produces a mycotoxin patulin that has a negative effect on human health. Currently, there is no available research in the literature on the resistance of Croatian traditional apple cultivars to contamination with P. expansum, and consequently, on the patulin content in apples and apple juice produced from those apples. Although the mechanism of apple resistance to fungal diseases has not yet been sufficiently investigated, some studies have shown that polyphenolic compounds have some impact on fungi growth. In order to contribute with new knowledge, this research deals with monitoring the growth of P. expansum on apples, patulin detection by LC/MS-MS, determination of polyphenol profile by validated HPLC method, and determining the effect of polyphenolic compounds on fungi growth and patulin production during apple storage. The results of this study have shown that Croatian traditional apple cultivars harvested from family farm Horvatić contain higher concentration of polyphenolic compounds and higher antioxidant activity. At the same time, they showed more resistance to infection by P. expansum than conventional ones. The higher content of dihydrochalcones and flavanols encouraged the biosynthesis of patulin in examined cultivars. However, the higher content of non-flavonoids such as 2-6 dimethoxybenzoic acid, 4-hydroxycinnamic acid and chlorogenic acid leads to decrease in content of patulin. In conclusion, it seems that content of polyphenols and patulin production are correlated.

Clinical Evidence of the Benefits of Phytonutrients in Human Healthcare

Phytonutrients comprise many different chemicals, including carotenoids, indoles, glucosinolates, organosulfur compounds, phytosterols, polyphenols, and saponins. This review focuses on the human healthcare benefits of seven phytochemical families and highlights the significant potential contribution of phytonutrients in the prevention and management of pathologies and symptoms in the field of family health. The structure and function of these phytochemical families and their dietary sources are presented, along with an overview of their potential activities across different health and therapeutic targets. This evaluation has enabled complementary effects of the different families of phytonutrients in the same area of health to be recognized.

Phenolic Content and Antioxidant Activity in Apples of the ‘Galaval’ Cultivar Grown on 17 Different Rootstocks

Apple cultivars are one of the main factors setting the composition of bioactive compounds in apples and the quality of the fruit. However, research has been providing increasing amounts of data on the influence of rootstocks on the variations in the composition of bioactive compounds in apples. The aim of the study was to determine the influence of rootstocks on the changes in the qualitative and quantitative composition of phenolic compounds and their antioxidant activity in vitro in apple flesh and peel. HPLC analyses of phenolic compounds in apple samples were performed. The rootstock–scion combination had a significant effect on the composition and antioxidant activity of phenolic compounds in apple samples. Depending on the rootstock, the total content of phenolic compounds in apple flesh of the ‘Galaval’ cultivar could vary by 2.9 times, and in the peel by up to 90%. The genotype of the rootstock resulted in the highest variation in total flavan-3-ol content in apple flesh—by as much as 4.3 times—while the total content of flavonols varied by 2.1 times. In apple peel, on the contrary, the greatest variation was recorded for the total flavonol content (by 4.4 times), and the total flavan-3-ol content varied the least (by 1.8 times). A proper match of a cultivar and a rootstock can program a fruit tree to grow larger amounts of higher-quality, antioxidant-rich, and high-nutrition-value fruit.

Impact of Storage Controlled Atmosphere on the Apple Phenolic Acids, Flavonoids, and Anthocyanins and Antioxidant Activity In Vitro

Apples are seasonal fruits, and it is important to prepare them adequately for storage and ensure proper storage conditions. In this study, we used ten different apple cultivars: ‘Alva’, ‘Auksis’, ‘Connell Red’, ‘Cortland’, ‘Ligol’, ‘Lodel’, ‘Noris’, ‘Rubin’, ‘Sampion’, and ‘Spartan’. We studied the qualitative and quantitative composition of phenolic compounds in the apple and apple extracts antioxidants activity before placing them in the controlled atmosphere chambers and again at the end of the experiment, eight months later. Different concentrations of O2, CO2, and N2, constant temperature, relative humidity, and removal of endogenous ethylene were continually maintained. HPLC analysis showed that the highest amount of 2265.7 ± 152.5 µg/g of chlorogenic acid was found in apple samples of the ‘Auksis’ cultivar stored under variant IV conditions. Different concentrations of gas in the controlled atmosphere chambers caused changes in antioxidant activity in whole apple and apple peel extracts. In our study, we found that the antioxidant activity of apple extracts varied between samples of different apple cultivars and depended on the composition of the controlled atmosphere. Determining the optimal storage conditions is beneficial to providing the consumers with apples that have a known and minimally altered chemical composition of phenolic compounds and the strongest antioxidant activity, which determine the use of apples in the healthy food chain.

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.

Onco-Preventive and Chemo-Protective Effects of Apple Bioactive Compounds

Cancer is one of the leading causes of death globally. Epidemiological studies have strongly linked a diet high in fruits to a lower incidence of cancer. Furthermore, extensive research shows that secondary plant metabolites known as phytochemicals, which are commonly found in fruits, have onco-preventive and chemo-protective effects. Apple is a commonly consumed fruit worldwide that is available all year round and is a rich source of phytochemicals. In this review, we summarize the association of apple consumption with cancer incidence based on findings from epidemiological and cohort studies. We further provide a comprehensive review of the main phytochemical patterns observed in apples and their bioavailability after consumption. Finally, we report on the latest findings from in vitro and in vivo studies highlighting some of the key molecular mechanisms targeted by apple phytochemicals in relation to inhibiting multiple 'hallmarks of cancer' that are important in the progression of cancer.

Flavonoids as Molecules With Anti-Zika virus Activity

Zika virus (ZIKV) is an arthropod-born virus that is mainly transmitted to humans by mosquitoes of the genus Aedes spp. Since its first isolation in 1947, only a few human cases had been described until large outbreaks occurred on Yap Island (2007), French Polynesia (2013), and Brazil (2015). Most ZIKV-infected individuals are asymptomatic or present with a self-limiting disease and nonspecific symptoms such as fever, myalgia, and headache. However, in French Polynesia and Brazil, ZIKV outbreaks led to the diagnosis of congenital malformations and microcephaly in newborns and Guillain-Barré syndrome (GBS) in adults. These new clinical presentations raised concern from public health authorities and highlighted the need for anti-Zika treatments and vaccines to control the neurological damage caused by the virus. Despite many efforts in the search for an effective treatment, neither vaccines nor antiviral drugs have become available to control ZIKV infection and/or replication. Flavonoids, a class of natural compounds that are well-known for possessing several biological properties, have shown activity against different viruses. Additionally, the use of flavonoids in some countries as food supplements indicates that these molecules are nontoxic to humans. Thus, here, we summarize knowledge on the use of flavonoids as a source of anti-ZIKV molecules and discuss the gaps and challenges in this area before these compounds can be considered for further preclinical and clinical trials.

Daily apple consumption reduces plasma and peripheral blood mononuclear cell-secreted inflammatory biomarkers in adults with overweight and obesity: a 6-week randomized, controlled, parallel-arm trial

BACKGROUND

Obesity-associated low-grade inflammation contributes to the development of cardiovascular disease (CVD). Apples are rich in anti-inflammatory bioactives including polyphenols and fiber.

OBJECTIVES

We aimed to determine the effects of regular apple consumption on fasting plasma biomarkers of inflammation (primary outcome), endotoxemia, carbohydrate and lipid metabolism (glucose, insulin, triacylglycerol; secondary outcomes), and peripheral blood mononuclear cell (PBMC)-secreted cytokines (secondary outcome) in individuals with overweight and obesity.

METHODS

A randomized, controlled, parallel-arm trial was conducted with n = 46 participants. After avoiding foods and beverages rich in polyphenols and fiber for 2 wk, participants consumed 3 whole Gala apples (∼200 g edible parts)/d as part of their habitual diet (n = 23) or avoided apples (control, n = 23) for 6 wk. All participants limited consumption of polyphenols and fiber during the 6-wk trial. Fasting blood samples were collected before and after 6 wk for analysis of plasma biomarkers and isolation of PBMCs, which were cultured for 24 h unstimulated or stimulated with LPS (10 ng/mL).

RESULTS

Forty-four participants completed the trial (30 female, 14 male; mean ± SEM age: 45.4 ± 2.2 y; BMI: 33.4 ± 0.9 kg/m2). After ANCOVA and correcting for multiple comparisons, apples decreased fasting plasma C-reactive protein by 17.0% (range: 14.3%-19.6%, P = 0.005), IL-6 by 12.4% (range: 6.7%-17.5%, P < 0.001), and LPS-binding protein by 20.7% (range: 14.1%-26.4%, P < 0.001) compared with control. Apples also decreased PBMC-secreted IL-6 by 28.3% (range: 22.4%-33.5%, P < 0.001) and IL-17 by 11.0% (range 5.8-15.6%, P = 0.003) in the unstimulated condition compared with control. Exploratory analysis showed apples also increased plasma total antioxidant capacity by 9.6% (range: 1.7-18.9%, P = 0.002) compared with control. However, apples had no effect on anthropometric or other CVD risk markers.

CONCLUSIONS

Six-week daily whole Gala apple consumption may be an effective dietary strategy to mitigate the obesity-associated inflammation that exacerbates CVD risk, without weight loss. This trial was registered at clinicaltrials.gov as NCT03523403.

Comparative Study on Seed Characteristics, Antioxidant Activity, and Total Phenolic and Flavonoid Contents in Accessions of Sorghum bicolor (L.) Moench

Sorghum is a major cereal food worldwide, and is considered a potential source of minerals and bioactive compounds. Its wide adaptive range may cause variations in its agronomic traits, antioxidant properties, and phytochemical content. This extensive study investigated variations in seed characteristics, antioxidant properties, and total phenolic (TPC) and flavonoid contents (TFC) of sorghum collected from different ecological regions of 15 countries. The antioxidant potential of the seed extracts of various sorghum accessions was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis 3-ethylbenzothiazoline-6-sulfonate (ABTS) radical scavenging assays. Significant variations in TPC were observed among the sorghum accessions. All 78 sorghum accessions used in this study exhibited significant variations in TFC, with the lowest and highest amount observed in accessions C465 and J542, respectively. DPPH scavenging potential of the seed extracts for all the accessions ranged from 11.91 ± 4.83 to 1343.90 ± 81.02 µg mL⁻¹. The ABTS assay results were similar to those of DPPH but showed some differences in the accessions. Pearson’s correlation analysis revealed a wide variation range in the correlation between antioxidant activity and TPC, as well as TFC, among the sorghum accessions. A wide diversity range was also recorded for the seed characteristics (1000-seed weight and seed germination rate). A dendrogram generated from UPGMA clustering, based on seed traits, antioxidant activity, TPC, and TFC was highly dispersed for these accessions. Variations among the accessions may provide useful information regarding the phytoconstituents, antioxidant properties, and phytochemical contents of sorghum and aid in designing breeding programs to obtain sorghum with improved agronomic traits and bioactive properties.

Variation of Triterpenes in Apples Stored in a Controlled Atmosphere

Apples are seasonal fruits, and thus after harvesting apples of optimal picking maturity, it is important to prepare them properly for storage and to ensure proper storage conditions in order to minimize changes in the chemical composition and commercial quality of the apples. We studied the quantitative composition of triterpenic compounds in the whole apple, apple peel and apple flesh samples before placing them in the controlled atmosphere (CA) chambers, and at the end of the experiment, 8 months later. HPLC analysis showed that highest total amount of triterpenic compounds (1.99 ± 0.01 mg g^-1) was found in the whole apple samples of the 'Spartan' cultivar stored under variant VIII (O₂-20%, CO₂-3%, N₂-77%) conditions. Meanwhile, the highest amount of triterpenic compounds (11.66 ± 0.72 mg g^-1) was determined in the apple peel samples of the 'Auksis' cultivar stored under variant II (O₂-5%, CO₂-1%, N₂-94%) conditions. In the apple peel samples of the 'Auksis' cultivar stored under variant I (O₂-21%, CO₂-0.03%, N₂-78.97%) conditions, the amount of individual triterpenic compounds (ursolic, oleanolic, corosolic, and betulinic acids) significantly decreased compared with amount determined before the storage. Therefore, in the apple flesh samples determined triterpenic compounds are less stable during the storage under controlled atmosphere conditions compared with triterpenic compounds determined in the whole apple and apple peel samples.

Preventive Applications of Polyphenols in Dentistry-A Review

Polyphenols are natural substances that have been shown to provide various health benefits. Antioxidant, anti-inflammatory, and anti-carcinogenic effects have been described. At the same time, they inhibit the actions of bacteria, viruses, and fungi. Thus, studies have also examined their effects within the oral cavity. This review provides an overview on the different polyphenols, and their structure and interactions with the tooth surface and the pellicle. In particular, the effects of various tea polyphenols on bioadhesion and erosion have been reviewed. The current research confirms that polyphenols can reduce the growth of cariogenic bacteria. Furthermore, they can decrease the adherence of bacteria to the tooth surface and improve the erosion-protective properties of the acquired enamel pellicle. Tea polyphenols, especially, have the potential to contribute to an oral health-related diet. However, in vitro studies have mainly been conducted. In situ studies and clinical studies need to be extended and supplemented in order to significantly contribute to additive prevention measures in caries prophylaxis.

The Differences in the Flavan-3-ol and Procyanidin Contents of the Japanese 'Fuji' and 'Orin' Apples Using a Rapid Quantitative High-Performance Liquid Chromatography Method: Estimation of the Japanese Intake of Flavan-3-ols and Procyanidins from Apple as Case Study

Previously, we reported that apple polyphenols and their major active compounds, the flavan-3-ols and the procyanidins, can result in various health benefits in animals and humans, according to clinical studies. Here, we developed a rapid method for quantifying flavan-3-ols and procyanidins using high-performance liquid chromatography with fluorescence detection, where we investigated the amounts of flavan-3-ols and procyanidins in the Japanese major apple production centre, the Aomori Prefecture, from 2016 to 2018. The non-bagged ‘Fuji (n = 609)’, the bagged ‘Fuji (n = 1101)’, and the ‘Orin (n = 504)’ apples were evaluated in terms of their differences in flavan-3-ols and procyanidins based on apple variety and the controlled atmosphere storage. The bagging treatments of the ‘Fuji’ apples resulted in significantly higher concentrations of procyanidins, while changes in flavan-3-ols concentrations were not clearly observed by treatment. In addition, ‘Orin’ had a significantly higher concentration of procyanidins than that of ‘Fuji’. In contrast, the controlled atmosphere storage hardly caused any changes in the flavan-3-ol and procyanidin contents. Hence, we present the concentrations of flavan-3-ols and procyanidins in major Japanese apples using the rapid high-performance liquid chromatography method with fluorescence detection.

Formulation and Quality Evaluation of Antioxidant Rich Bars Enriched with Chia seed, Whole Mango, Apple and Guava

An insalubrious diet regime and lack of physical exercise are the root causes for the causation of metabolic diseases. Thus, need for food choices that are nutritious, rich in antioxidants and are ready to eat has grown to a great extent. Accordingly, the present study was planned to develop an antioxidant rich bar with puffed wheat, Chia seed, mango (Leather+peel powder), apple (whole fruit Leather), guava (whole fruit Leather), peanut and honey in different proportions using standard bar moulds. Therefore, three types of bars were prepared, namely mango Chia seed bar, apple Chia seed bar and guava Chia seed bar. Formulated mango Chiaseed bar of 55g showed the highest overall acceptability with 2g mango peel powder and 8g mango leather. Apple Chiaseed bar and guava Chia seed bar were found acceptable on incorporation of 5g leather of apple and guava respectively. The fatty acid profile of the selected bars showed significant increase (p<0.01) in PUFA content. A significant increase (p<0.01) was found in vitamin C and β-carotene content, both of which act as a good natural antioxidants. The bioactive component and antioxidants such as total phenols, flavonoids, tannins showing DPPH, FRAP, ABTS and RPA activity elevated to significant (p<0.01) levels with the highest content in mango chia seed bar. The bar prepared was acceptable and nutrient-dense, therefore can be consumed by the general population to prevent and cure lifestyle diseases by increasing antioxidant content in their diet.

Electroactive Phenolic Contributors and Antioxidant Capacity of Flesh and Peel of 11 Apple Cultivars Measured by Cyclic Voltammetry and HPLC-DAD-MS/MS

In this study, 11 apple cultivars were characterized by their total phenolic content (TPC) and total flavonoid content (TFC) and antioxidant, reducing, and chelating capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) test, cyclic voltammetry (CV), and ferric reducing antioxidant power (FRAP) assays; and ferrous ion chelating capacity. The phenolic compounds in flesh and peel were determined by liquid chromatography coupled to mass spectrometry and diode array detector (HPLC-DAD-MS/MS) and their electroactivity by CV. The results showed higher TPC, TFC, and antioxidant capacity by DPPH test in the peels of all apple cultivars as compared to the respective flesh. The peel extracts also showed two-fold higher FRAP values as compared to the flesh extracts. The reducing capacity of the peel and flesh determined by CV measurements confirmed the results achieved by spectrophotometric methods of evaluating antioxidant capacity. There was no significant difference in chelating capacity in the peel and flesh. The HPLC-DAD-MS/MS analysis showed the presence of 11 phenolic compounds in the peel and flesh which varied in antioxidant, reducing, and chelating activity. The order of the phenolic compound content in flesh and peel in Quinte cultivar, which showed the highest antioxidant capacity, was as follows: epicatechin > chlorogenic acid > quercetin 3-arabinoside > quercetin 3-glucoside > cyanidin 3-galactoside > quercetin 3-rhamnoside > catechin > phloridzin > rutin > phloretin = quercetin. CV results were highly correlated with those obtained by spectrophotometry and HPLC-DAD-MS/MS, providing evidence to support the use of cyclic voltammetry as a rapid method to determine the phenolic profile and reducing the power of apple flesh and peel. The association between antioxidant assays and phenolic compound content showed that the highest contribution to the antioxidant capacity of apple peel and flesh was provided by catechin, epicatechin, and cyadinin-3-galactoside, while phloretin, phloridzin, and chlorogenic acid were the main contributors to chelating activity. Results from this study clearly indicate that removing the peel from apples may induce a significant loss of antioxidants.

Effect of drying methods and storage with agro-ecological conditions on phytochemicals and antioxidant activity of fruits: a review

Choice of drying methods significantly impacts the nutritive and non-nutritive compounds in fruits and vegetables. Phytochemicals such as total phenolics and total flavonoids are non-nutritive bioactive compounds and are found in plants which are of important value due to their antioxidant properties in minimizing the oxidation reaction. However, drying and storage conditions and duration significantly affect these important quality attributes. There is currently no review article on the impact of the drying and storage conditions on these quality attributes. Therefore, the aim of this review paper is to investigate the impact of drying methods on these important phytochemicals and their antioxidant activity on dried products during the storage period. Different drying methods cause desirable and undesirable changes to dried products both physically and chemically. It is found that during the drying process at various temperature ranges from 40 to 80 °C, chemical changes occurs which affects the phenolic and the flavonoid content of dried products to increase or decrease. The increase in antioxidant activity after drying is also due to oxidized polyphenols and Maillard reaction products. This results to changes in the antioxidant potential of the dried food product and its impact on the shelf life.

Chlorogenic acid: A comprehensive review of the dietary sources, processing effects, bioavailability, beneficial properties, mechanisms of action, and future directions

Chlorogenic acids (CGAs), a group of hydroxycinnamates, are generally abundant in everyday foods and beverages, most prominently in certain coffee drinks. Among them, the chlorogenic acid (CGA), also termed as 5-O-caffeoylquinic acid (5-CQA), is one of the most abundant, highly functional polyphenolic compounds in the human diet. The evidence of its health benefits obtained from clinical studies, as well as basic research, indicates an inverse correlation between 5-CQA consumption and a lower risk of metabolic syndromes and chronic diseases. This review focuses on the beneficial properties for health and mechanisms of action of 5-CQA, starting with its history, isomers, dietary sources, processing effects, preparation methods, pharmacological safety evaluation, and bioavailability. It also provides the possible molecular mechanistic bases to explain the health beneficial effects of 5-CQA including neuroprotective, cardiovascular protective, gastrointestinal protective, renoprotective, hepatoprotective, glucose and lipid metabolism regulatory, and anticarcinogenic effects. The information summarized here could aid in the basic and clinical research on 5-CQA as a natural dietary additive, potential drug candidate, as well as a natural health promoter.

Phenolic composition of 91 Australian apple varieties: towards understanding their health attributes

INTRODUCTION

Apples, an important contributor to total dietary phenolic intake, are associated with cardiovascular health benefits. Determining the phenolic composition of apples, their individual variation across varieties, and the phenolic compounds present in plasma after apple consumption is integral to understanding the effects of apple phenolics on cardiovascular health.

METHODS

Using liquid chromatography we quantified five important polyphenols and one phenolic acid with potential health benefits: quercetin glycosides, (-)-epicatechin, procyanidin B2, phloridzin, anthocyanins, and chlorogenic acid, in the skin and flesh of 19 apple varieties and 72 breeding selections from the Australian National Apple Breeding program. Furthermore, we measured the phenolic compounds in the plasma of 30 individuals post-consumption of an identified phenolic-rich apple, Cripp's Pink.

RESULTS

Considerable variation in concentration of phenolic compounds was found between genotypes: quercetin (mean ± SD: 16.1 ± 5.9, range: 5.8-30.1 mg per 100 g); (-)-epicatechin (mean ± SD: 8.6 ± 5.8, range: 0.2-19.8 mg per 100 g); procyanidin B2 (mean ± SD: 11.5 ± 6.6, range: 0.5-26.5 mg per 100 g); phloridzin (mean ± SD: 1.1 ± 0.6, range: 0.3-4.3 mg per 100 g); anthocyanins (mean ± SD: 1.8 ± 4.4, range: 0-40.8 mg per 100 g); and chlorogenic acid (mean ± SD: 11.3 ± 9.9, range: 0.4-56.0 mg per 100 g). All phenolic compounds except chlorogenic acid were more concentrated in the skin compared with flesh. We observed a significant increase, with wide variation, in 14 phenolic compounds in plasma post-consumption of a phenolic-rich apple.

CONCLUSION

This information makes an important contribution to understanding the potential health benefits of apples.

Impact of the Physicochemical Composition and Microbial Diversity in Apple Juice Fermentation Process: A Review

Fermented apple beverages are produced all over the world with diverse characteristics associated with each country. Despite the diversifications, cider producers are confronted with similar issues and risks. The nature of the raw material, also known as the fermentation medium, plays a key role in fermentation. A well-defined composition of apples is, therefore, required to produce cider with good quality. In addition, ferment and its metabolism are important factors in the fermentation process. The producers of cider and other alcoholic beverages are looking in general for novel yeast strains or for the use of native strains to produce "authentic" and diversified beverages that are distinct from each other, and that attract more and more consumers. Research articles on cider production are infrequent compared to wine production, especially on the impact of the chemical composition and microbial diversity of apples on fermentation. Even though the processing of fermented beverages is close in terms of microbial interactions and production, the study of the specific properties of apples and the production challenges of cider production is advantageous and meaningful for cider producers. This review summarizes the current knowledge on apple composition and the impact of the must composition on fermentation and yeast growth. In addition, the microbial diversity of cider, activities, and its influence on fermentation are reviewed.

Apple polyphenol-rich drinks dose-dependently decrease early-phase postprandial glucose concentrations following a high-carbohydrate meal: a randomized controlled trial in healthy adults and in vitro studies

BACKGROUND

Previous research demonstrated that a high dose of phlorizin-rich apple extract (AE) can markedly inhibit early-phase postprandial glycemia, but efficacy of lower doses of the AE is unclear.

OBJECTIVE

To determine whether lower AE doses reduce early-phase postprandial glycemia in healthy adults and investigate mechanisms.

DESIGN

In a randomized, controlled, double-blinded, cross-over acute trial, drinks containing 1.8 g (HIGH), 1.35 g (MED), 0.9 g (LOW), or 0 g (CON) of a phlorizin-rich AE were consumed before 75 g starch/sucrose meal. Postprandial blood glucose, insulin, C-peptide, glucose-dependent insulinotropic polypeptide (GIP) and polyphenol metabolites concentrations were measured 0-240 min, acetaminophen concentrations to assess gastric emptying rate, and 24 h urinary glucose excretion. Effects of AE on intestinal glucose transport were investigated in Caco-2/TC7 cells.

RESULTS

AE significantly reduced plasma glucose iAUC 0-30 min at all doses: mean differences (95% CI) relative to CON were -15.6 (-23.3, -7.9), -11.3 (-19.6, -3.0) and -8.99 (-17.3, -0.7) mmol/L per minute for HIGH, MEDIUM and LOW respectively, delayed T_max (HIGH, MEDIUM and LOW 45 min vs. CON 30 min), but did not lower C_max. Similar dose-dependent treatment effects were observed for insulin, C-peptide, and GIP. Gastric emptying rates and urinary glucose excretion did not differ. Serum phloretin, quercetin and epicatechin metabolites were detected postprandially. A HIGH physiological AE dose equivalent decreased total glucose uptake by 48% in Caco-2/TC7 cells.

CONCLUSIONS

Phlorizin-rich AE, even at a low dose, can slightly delay early-phase glycemia without affecting peak and total glycemic response.

New progress in the pharmacology of protocatechuic acid: A compound ingested in daily foods and herbs frequently and heavily

Protocatechuic acid is a natural phenolic acid, which widely exists in our daily diet and herbs. It is also one of the main metabolites of complex polyphenols, such as anthocyanins and proanthocyanins. In recent years, a large number of studies on the pharmacological activities of protocatechuic acid have emerged. Protocatechuic acid has a wide range of pharmacological activities including antioxidant, anti-inflammatory, neuroprotective, antibacterial, antiviral, anticancer, antiosteoporotic, analgesia, antiaging activties; protection from metabolic syndrome; and preservation of liver, kidneys, and reproductive functions. Pharmacokinetic studies showed that the absorption and elimination rate of protocatechuic acid are faster, with glucuronidation and sulfation being the major metabolic pathways. However, protocatechuic acid displays a dual-directional regulatory effect on some pharmacological activities. When the concentration is very high, it can inhibit cell proliferation and reduce survival rate. This review aims to comprehensively summarize the pharmacology, pharmacokinetics, and toxicity of protocatechuic acid with emphasis on its pharmacological activities discovered in recent 5 years, so as to provide more up-to-date and thorough information for the preclinical and clinical research of protocatechuic acid in the future. Moreover, it is hoped that the clinical application of protocatechuic acid can be broadened, giving full play to its characteristics of rich sources, low toxicity and wide pharmacological activites.

The role of anthocyanins as antidiabetic agents: from molecular mechanisms to in vivo and human studies

Diabetes mellitus is a chronic metabolic disease characterized by high blood glucose concentration. Nowadays, type 2 diabetes or insulin resistant diabetes is the most common diabetes, mainly due to unhealthy lifestyle. Healthy habits like appropriate nutritional approaches or the consumption of certain natural products or food supplements have been suggested as non-pharmacological strategies for the treatment and prevention of type 2 diabetes. Some of the main bioactive compounds from plant foods are polyphenols, important mainly for their antioxidant capacity in oxidative stress conditions and ageing. Anthocyanins are polyphenols of the flavonoid group, which act as pigments in plants, especially in fruits such as berries. A search of in vitro, in vivo and human studies in relation with antidiabetic properties of anthocyanins has been performed in different electronic databases. Results of this review demonstrate that these compounds have the ability to inhibit different enzymes as well as to influence gene expression and metabolic pathways of glucose, such as AMPK, being able to modulate diabetes and other associated disorders, as hyperlipidaemia, overweight, obesity and cardiovascular diseases. Additionally, human interventional studies have shown that high doses of anthocyanins have potential in the prevention or treatment of type 2 diabetes; nevertheless, anthocyanins used in these studies should be standardized and quantified in order to make general conclusions about its use and to claim benefits for the human population.

Increasing the nutritional value of strawberry puree by adding xylo-oligosaccharides

The present study identified the threshold concentration of xylo-oligosaccharides (XOS) that resulted in minimal quality changes (rheology, color, water activity, pH, and total soluble solids) in strawberry puree. Optimization of XOS concentration to 5% (w/w) did not significantly alter the quality attributes of the strawberry puree. In addition, this study also monitored the rheological properties, composition (total soluble solids, total phenolic content, flavonoids, and tannin content), physicochemical attributes (color, water activity, pH) and sensorial properties of XOS-enhanced (5%, w/w) strawberry puree after thermal processing (HTST: 75 °C, 15s and UHT: 121 °C, 2s) and storage after 1, 15, and 36 days at 4 °C and 55 °C. At 5% (w/w) concentration, the addition of XOS increased consumer preference without significantly compromising quality attributes. Thermally treated strawberry puree (HTST and UHT) were less preferred by consumers than fresh puree. However, all strawberry samples incorporated with XOS (5%, w/w) received statistically higher scores than the samples without the XOS addition. Thus, the proposed supplementation of strawberry puree with XOS could be a viable solution to increase consumers' dietary fiber intake with little need for behavioral changes.

Postharvest changes in phenolic compounds and antioxidant capacity of apples cv. Jonagold growing in different locations in Europe

Apples cv. 'Jonagold' of the same quality were collected from four orchards in three European countries. The orchards differed in terms of longitude, latitude and microclimate. The apples were stored in controlled atmosphere storage for six months. Both after harvest and after storage the apples were compared in terms of physical and chemical properties. Differences in firmness, titratable acidity, total soluble solids, mass varied not >11%. Storability was little affected by harvest location. The sum of polyphenols was more strongly influenced by storage than by orchard location. The strongest degradation of flavonols after storage was in apples grown in the most southern region of harvest (Italy). The content of (+)- catechin and (-)-epicatechin depended on harvest location and its strong increase resulted in higher content of procyanidins and flavanols after storage. Changes in individual polyphenols were significant after storage and depended on harvest location.

Unified Flavor Quantitation: Toward High-Throughput Analysis of Key Food Odorants and Tastants by Means of Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry

Because foods are perceived through combined inputs from taste and odor, which are determined by the concentration of the individual odor and taste molecules, the unified high-throughput quantitation of volatile odorants and non-volatile tastants with the very same instrumental setup has been a long-standing but yet unmet dream. The research presented here for the first time demonstrates, after only minimal sample workup, the highly accurate, rapid, and sensitive unified quantitation of odorants and tastants of key flavor molecules in apple juice on a single ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) platform over a large dynamic range of up to 6 orders of magnitude. While flavor-active aldehydes, ketones, and organic acids were analyzed after derivatization with 3-nitrophenylhydrazine, taste-active polyphenols and odor-active esters were directly analyzed by means of UHPLC-MS/MS with and without target analyte enrichment through stir-bar sorptive extraction. This "unified flavor quantitation" approach holds promise to accelerate the transition of today's labor and time-consuming, low-throughput analysis of odorants and tastants into a new era of high-performance quantitation of key flavor molecules.

Resource allocation trade-offs and the loss of chemical defences during apple domestication

BACKGROUND AND AIMS

Most crops have been dramatically altered from their wild ancestors with the primary goal of increasing harvestable yield. A long-held hypothesis is that increased allocation to yield has reduced plant investment in defence and resulted in crops that are highly susceptible to pests. However, clear demonstrations of these trade-offs have been elusive due to the many selective pressures that occur concurrently during crop domestication.

METHODS

To provide a robust test of whether increased allocation to yield can alter plant investment in defence, this study examined fruit chemical defence traits and herbivore resistance across 52 wild and 56 domesticated genotypes of apples that vary >26-fold in fruit size. Ninety-six phenolic metabolites were quantified in apple skin, pulp and seeds, and resistance to the codling moth was assessed with a series of bioassays.

KEY RESULTS

The results show that wild apples have higher total phenolic concentrations and a higher diversity of metabolites than domesticated apples in skin, pulp and seeds. A negative phenotypic relationship between fruit size and phenolics indicates that this pattern is driven in part by allocation-based trade-offs between yield and defence. There were no clear differences in codling moth performance between wild and domesticated apples and no overall effects of total phenolic concentration on codling moth performance, but the results did show that codling moth resistance was increased in apples with higher phenolic diversity. The concentrations of a few individual compounds (primarily flavan-3-ols) also correlated with increased resistance, primarily driven by a reduction in pupal mass of female moths.

CONCLUSIONS

The negative phenotypic relationship between fruit size and phenolic content, observed across a large number of wild and domesticated genotypes, supports the hypothesis of yield-defence trade-offs in crops. However, the limited effects of phenolics on codling moth highlight the complexity of consequences that domestication has for plant-herbivore interactions. Continued studies of crop domestication can further our understanding of the multiple trade-offs involved in plant defence, while simultaneously leading to novel discoveries that can improve the sustainability of crop production.

Beyond the Antioxidant Activity of Dietary Polyphenols in Cancer: the Modulation of Estrogen Receptors (ERs) Signaling

The potential "health benefits" of dietary polyphenols have been ascribed to their direct antioxidant activity and their impact on the regulation of cell and tissue redox balance. However, because of the relative poor bioavailability of many of these compounds, their effects could not be easily explained by the antioxidant action, which may occur only at high circulating and tissue concentrations. Therefore, many efforts have been put forward to clarify the molecular mechanisms underlining the biological effect of polyphenols in physiological and pathological conditions. Polyphenols' bioavailability, metabolism, and their effects on enzyme, membrane, and/or nuclear receptors and intracellular transduction mechanisms may define the overall impact of these compounds on cancer risk and progression, which is still debated and not yet clarified. Polyphenols are able to bind to estrogen receptor α (ERα) and β (ERβ), and therefore induce biological effects in human cells through mimicking or inhibiting the action of endogenous estrogens, even at low concentrations. In this work, the role and effects of food-contained polyphenols in hormone-related cancers will be reviewed, mainly focusing on the different polyphenols' mechanisms of action with particular attention on their estrogen receptor-based effects, and on the consequences of such processes on tumor progression and development.

LC-QTOF characterization of non-anthocyanic flavonoids in four Tunisian fig varieties

Flavonoids are compounds characterized by antioxidant activity, and their intake in the human diet is considered useful for health and nutrition. Non-anthocyanic flavonoids in 4 different types of Tunisian figs belonging to the smyrna-type Ficus carica varieties known as Kholi, Tchich Asal, Himri, and Bidhi were studied by liquid chromatography/high-resolution mass spectrometry UHPLC-QqTOF. Twenty-two compounds belonging to the classes of flavanones (naringenin and eriodictyol), flavones (3 apigenin and 5 luteolin derivatives), and flavonols (2 kaempferol and 7 quercetin derivatives) were identified. Three O-methoxy flavonols (tamarixetin, syringetin, and isorhamnetin-3-O-glucoside) were found in figs for the first time. Total content of non-anthocyanic flavonoids found in dark varieties (between 410 and 830 mg/kg) show that these F. carica are fruits qualitatively and quantitatively rich of dietary polyphenols.

Apple Intrinsic Factors Modulating the Global Regulator, LaeA, the Patulin Gene Cluster and Patulin Accumulation During Fruit Colonization by Penicillium expansum

The mycotoxin patulin is produced in colonized tissue by Penicillium expansum during storage of apples and is significantly affected by environmental factors that contribute to its accumulation. Few reports have, however, examined the effect of natural intrinsic factors associated with the fruit on the production of patulin. Here, we find that with advancing maturity, Golden Delicious apples show increased concentrations of total soluble solids (TSS) from 14 to 17% associated with the increased expression of the global transcription factor involved in regulation of secondary metabolite biosynthesis in filamentous fungi, laeA expression and patulin accumulation. However, the apple cultivar Granny Smith, with similar TSS values but differing in pH levels and malic acid concentrations, showed reduced expression levels of laeA and the patulin biosynthesis gene cluster (pat genes) and patulin accumulation, suggesting a complexity of host factors contribution to patulin accumulation during P. expansum colonization. To start elucidating these apple intrinsic factors, we examined their in vitro impact on laeA and pat gene expression concomitant with patulin synthesis. Increasing sucrose concentrations from 15 to 175 mM repressed laeA and pat gene expression and patulin production. However, this affect was modified and often reversed and sometimes accentuated by changes in pH, or the addition of malic acid or the major apple phenolic compounds, chlorogenic acid and epicatechin. While the increase in malic acid from 0 to 1% increased laeA and pat gene expression, the decrease in pH from 3.5 to 2.5 reduced their expression. Also the increased laeA and pat genes expressions at increasing epicatechin concentrations from 0 to 1 mM, was reversed by increasing sucrose concentrations, all together suggesting the complexity of the interactions in vivo.

Diversity of bioactive compounds and antioxidant activity in Delicious group of apple in Western Himalaya

Apple contributes significantly to the livelihood and health of the people living in Himalayan regions. Among others, the Delicious group of apple is known for their health promoting and income generating attributes. However, the systematic investigation on morphological and phytochemical attributes of the apple growing in Indian Himalayan region is poorly known. An altitude-dependent variation in the fruit quality traits and phytochemical diversity was observed. The Royal Delicious was found rich in total tannin, flavonoids, flavonols, antioxidant activity [2,2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid), 2,2-Diphenyl-1-picryhydrazyl, Ferric reducing antioxidant power], procyanidin B₂, phloridzin and gallic acid; Red Delicious for total phenol and epicatechin and Golden Delicious for chlorogenic acid. The cultivar and altitude-dependent variation of phenolic profile in peel and pulp portion emphasizes genotype-specific biosynthesis of phenolic compounds in regulatory mechanisms. It is suggested that selection of suitable altitude and cultivars is required for harnessing the maximum phytochemical and antioxidant activity for benefits to human consumption.

Polyphenolic Compounds Analysis of Old and New Apple Cultivars and Contribution of Polyphenolic Profile to the In Vitro Antioxidant Capacity

Polyphenols are antioxidant ingredients in apples and are related to human health because of their free radical scavenging activities. The polyphenolic profiles of old and new apple cultivars (n = 15) were analysed using high-performance liquid chromatography (HPLC) with diode array detection (DAD). The in vitro antioxidant capacity was determined by total phenolic content (TPC) assay, hydrophilic trolox equivalent antioxidant capacity (H-TEAC) assay and hydrophilic oxygen radical absorbance (H-ORAC) assay. Twenty polyphenolic compounds were identified in all investigated apples by HPLC analysis. Quercetin glycosides (203 ± 108 mg/100 g) were the main polyphenols in the peel and phenolic acids (10 ± 5 mg/100 g) in the flesh. The calculated relative contribution of single compounds indicated flavonols (peel) and vitamin C (flesh) as the major contributors to the antioxidant capacity, in all cultivars investigated. The polyphenolic content (HPLC data) of the flesh differed significantly between old (29 ± 7 mg/100 g) and new (13 ± 4 mg/100 g) cultivars, and the antioxidant capacity of old apple cultivars was up to 30% stronger compared to new ones.

Phenolic acids in cereal grain: Occurrence, biosynthesis, metabolism and role in living organisms

Studies on plant metabolism, including those on cereals, increasingly focus on plant phenolic compounds, e.g. phenolic acids and flavonoids. The aim of this study was to present a comprehensive picture of major phenolic acids in grain, starting from their biosynthesis, their occurrence and finally their role in the vegetation of cereals. It is clearly connected with the polygenic plant resistance to pathogens, particularly toxin-forming fungi. Other crucial aspects include the transformations that take place during the technological processing of grain, their metabolic pathway in the human organism as well as the presentation of the health-promoting effect of grain processing products containing phenolic acids. These compounds are used as precursors of bioactive compounds commonly applied both for therapeutic purposes and in the cosmetics, engineering and food industries. An advantage of phenolic acids is the fact that they may be metabolized by microorganisms found in nature and thus they provide an alternative to the increasing load of man-made chemicals in the environment.

The influence of plant protection by effective microorganisms on the content of bioactive phytochemicals in apples

BACKGROUND

The phytochemicals of two apple cultivars (Yellow Transparent and Early Geneva) protected in two ways, conventionally with chemical pesticides or by effective microorganisms (EM), were compared. Two types of components were determined: lipids synthesised constitutively and generated via inducible pathways polyphenols along with antioxidant activity and profiles.

RESULTS

The antioxidant activities assessed with ABTS, DPPH and Folin-Ciocalteu reagents were about two-fold higher in the case of microbiologically protected apples. The qualitative composition of phenolics determined by LC-DAD-MS varied between cultivars and the part of apples studied, while the method of protection caused mainly differences in concentration of some groups of polyphenols (hydroxycinnamates, flavanols, dihydrochalcones, flavonols, anthocyanins). The apples from biological cultivation contained about 34-54% more phenolics than these from a conventional orchard. In contrast, lipid composition did not differ significantly between apples originating from conventional and bio-crops.

CONCLUSION

The results indicate that the advantage of using the EM technology in agriculture may not only be the reduction of consumption of chemical fertilisers and synthetic pesticides, but also, at least in the case of apples, may lead to the production of crops with improved health quality due to the higher content of bioactive phytochemicals. © 2017 Society of Chemical Industry.

Characterization of the Polyphenolic Profiles of Peel, Flesh and Leaves of Malus domestica Cultivars Using UHPLC-DAD-HESI-MSn

Qualitative and quantitative analyses of polyphenols extracted from 21 Malus domestica cultivars using ultra high performance liquid chromatography with diode array detection coupled to heated electrospray ionization mass spectrometric detection was performed for separation of 27 phenolic compounds on a reversed phase UHPLC column with an optimized gradient consisting of 1% formic acid in water and 1% formic acid in methanol within 20 minutes. According to retention times, UV maxima and mass spectra of the peaks in the chromatograms obtained from extracts of apple peel, flesh and leaves, the polyphenolic compounds were identified and quantified. Based on fragmentation patterns, 6 phenolic acids, 5 flavan-3-ols, 5 dihydrochalcones, 8 flavonols and 3 flavone derivatives were characterized in the studied samples. The method was then employed for analysis of the polyphenolic pattern of 21 apple cultivars, both commercial and autochthonous for the Macedonian region, as well as for monitoring the influence of long term storage on the polyphenolic content and composition of apple fruits and for comparison of polyphenolic profiles of apple cultivars during two years of harvesting. The obtained results revealed minor differences in the quality and major variation in the content of phenolic compounds in the flesh, peel and leaves in the studied apple cultivars that is attributed mainly to cultivar differences and meteorological factors.

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.