Evaluation of fruit quality, bioactive compounds and total antioxidant activity of flat peach cultivars

Bioactive Compounds of Portuguese Fruits with PDO and PGI

The European Union has established two designations, Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI), to guarantee the authenticity of products with valued specificities associated with the regions where they are produced. The valorization of these products, particularly fruits, not only preserves their natural origins but also promotes the cultivalion of specific regional fruit varieties. This contributes to the preservation of biodiversity and the development of innovative bio-based products in the regions of production. In recent years, substantial efforts have been made to characterize PDO and PGI fruits, particularly in relation to the presence of bioactive compounds with antioxidant and antimicrobial properties. Portugal, with its diverse range of climates and geographical characteristics, is home to numerous fruits with unique flavors, textures, and appearances, many of which are now recognized with PDO or PGI seals. This review compiles data from the production of Portuguese fruits with PDO designations, such as the 'Maça Bravo de Esmolfe' (apple) and 'Pera Rocha do Oeste' (pear), and PGI designations, such as 'Citrinos do Algarve' (citrus)and 'Cereja da Cova da Beira' (cherry), and summarizes studies focusing on the bioactive compounds present in these fruits. The presence of bioactive compounds is a significant aspect of nutritious food, associated with health benefits that consumers are increasingly aware of and value.

Changes in the Phytochemical Profile and Antioxidant Properties of Prunus persica Fruits after the Application of a Commercial Biostimulant Based on Seaweed and Yeast Extract

Plant biostimulants are formulations that are experiencing great success from the perspective of sustainable agriculture. In this work, we evaluated the effect derived from the application of a biostimulant based on algae and yeast extracts (Expando^®) on the agronomic yield and nutraceutical profile of two different cultivars ("Sugar Time" and "West Rose") of Prunus persica (peach). Although, at the agronomic level, significant effects on production yields were not recorded, the biostimulant was able to reduce the ripening time, increase the fruit size, and make the number of harvestable fruits homogeneous. From a nutraceutical point of view, our determinations via spectrophotometric (UV/Vis) and chromatographic (HPLC-DAD-MS/MS) analysis showed that the biostimulant was able to boost the content of bioactive compounds in both the pulp (5.0 L/ha: +17%; 4.0 L/ha: +12%; 2.5 L/ha: +11%) and skin (4.0 L/ha: +38%; 2.5 L/ha: +15%). These changes seem to follow a dose-dependent effect, also producing attractive effects on the antioxidant properties of the fruits harvested from the treated trees. In conclusion, the biostimulant investigated in this work proved to be able to produce more marketable fruit in a shorter time, both from a pomological and a functional point of view.

Determination of Selected Beneficial Substances in Peach Fruits

Peaches (Prunus persica L.) are a popular and sought-after dessert fruit. This is mainly due to their flavour, aroma, attractive appearance, and high content of substances that play an important role in human nutrition. The present study was carried out to determine some important analytical properties (sugars/sucrose, glucose, fructose and sorbitol), total acid, total phenolics, flavonoids, antioxidant capacity, carotenoids and anthocyanins of 34 selected peach varieties. The analyses are also complemented by colorimetric measurements of peach skin colour using CIELAB and other chromatic parameters. The results show, for example, that all peach varieties are good sources of phenolic compounds (9.43–577 mg gallic acid equivalent (GAE).100 g−1), flavonoids (1.12–95.1 mg catechin equivalent (CAE).100 g−1), and antioxidant capacity (136–462 mg Trolox equivalent (TE).100 g−1).

Development of an artificial neural network as a tool for predicting the chemical attributes of fresh peach fruits

This investigation aimed to develop a method to predict the total soluble solids (TSS), titratable acidity, TSS/titratable acidity, vitamin C, anthocyanin, and total carotenoids contents using surface color values (L*, Hue and chroma), single fruit weight, juice volume, and sphericity percent of fresh peach fruit. Multiple regression analysis (MLR) and an artificial neural network (ANN) were employed. An ANN model was developed with six inputs and 15 neurons in the first hidden layer for the prediction of six chemical composition parameters. The results confirmed that the ANN model R² = 974–0.998 outperformed the MLR models R² = 0.473–0.840 using testing dataset. Moreover, sensitivity analysis revealed that the juice volume was the most dominating parameter for the prediction of titratable acidity, TSS/titratable acidity and vitamin C with corresponding contribution values of 39.97%, 50.40%, and 33.08%, respectively. In addition, sphericity percent contributed by 23.70% to anthocyanin and by 24.08% to total carotenoids. Furthermore, hue on TSS prediction was the highest compared with the other parameters, with a contribution percentage of 20.86%. Chroma contributed by different values to all variables in the range of 5.29% to 19.39%. Furthermore, fruit weight contributed by different values to all variables in the range of 16.67% to 23.48%. The ANN prediction method denotes a promising methodology to estimate targeted chemical composition levels of fresh peach fruits. The information of peach quality reported in this investigation can be used as a baseline for understanding and further examining peach fruit quality.

Antifungal mechanisms of lavender essential oil in the inhibition of rot disease caused by Monilinia fructicola in postharvest flat peaches

As a natural antimicrobial agent, lavender essential oil (LEO) is generally recognized to be safe and effective in the inhibition of phytopathogenic fungi. Direct contact and fumigation (in vivo and in vitro) were used to study the fungistatic effect of LEO on Monilinia fructicola. Additionally, the effect on the ultrastructure of cells and degree of destruction of the cell membrane of M. fructicola were revealed. In addition, the effects of LEO on the expression levels of particular apoptosis-related genes in M. fructicola cells were detected and GC-MS was used to analyse the main components of LEO. LEO had a good inhibitory efficacy against M. fructicola in flat peaches, with almost complete growth inhibition with 800 μL / L. These effects were associated with leakage of cytoplasm contents, hyphal distortion and spore disruption. Moreover, the expression of apoptosis RTG1 and RLM1 genes increased on LEO treatment. These results demonstrate that LEO can inhibit M. fructicola by inducing cytoplasmic membrane damage and cell apoptosis of fungi and that the major ingredients of LEO are monoterpenes and sesquiterpenes which are presumed to contribute to the inhibitory effects.

Application of a multilayer perceptron artificial neural network for identification of peach cultivars based on physical characteristics

In the fresh fruit industry, identification of fruit cultivars and fruit quality is of vital importance. In the current study, nine peach cultivars (Dixon, Early Grande, Flordaprince, Flordastar, Flordaglo, Florda 834, TropicSnow, Desertred, and Swelling) were evaluated for differences in skin color, firmness, and size. Additionally, a multilayer perceptron (MLP) artificial neural network was applied for identification of the cultivars according to these attributes. The MLP was trained with an input layer including six input nodes, a single hidden layer with six hidden nodes, and an output layer with nine output nodes. A hyperbolic tangent activation function was used in the hidden layer and the cross entropy error was given because the softmax activation function was functional to the output layer. Results showed that the cross entropy error was 0.165. The peach identification process was significantly affected by the following variables in order of contribution (normalized importance): polar diameter (100%), L∗ (89.0), b∗ (88.0%), a∗ (78.5%), firmness (71.3%), and cross diameter (37.5.3%). The MLP was found to be a viable method of peach cultivar identification and classification because few identifying attributes were required and an overall classification accuracy of 100% was achieved in the testing phase. Measurements and quantitative discrimination of peach properties are provided in this research; these data may help enhance the processing efficiency and quality of processed peaches.

Stone Fruit as Biofactories of Phytochemicals With Potential Roles in Human Nutrition and Health

Phytochemicals or secondary metabolites present in fruit are key components contributing to sensory attributes like aroma, taste, and color. In addition, these compounds improve human nutrition and health. Stone fruits are an important source of an array of secondary metabolites that may reduce the risk of different diseases. The first part of this review is dedicated to the description of the main secondary organic compounds found in plants which include (a) phenolic compounds, (b) terpenoids/isoprenoids, and (c) nitrogen or sulfur containing compounds, and their principal biosynthetic pathways and their regulation in stone fruit. Then, the type and levels of bioactive compounds in different stone fruits of the Rosaceae family such as peach (Prunus persica), plum (P. domestica, P. salicina and P. cerasifera), sweet cherries (P. avium), almond kernels (P. dulcis, syn. P. amygdalus), and apricot (P. armeniaca) are presented. The last part of this review encompasses pre- and postharvest treatments affecting the phytochemical composition in stone fruit. Appropriate management of these factors during pre- and postharvest handling, along with further characterization of phytochemicals and the regulation of their synthesis in different cultivars, could help to increase the levels of these compounds, leading to the future improvement of stone fruit not only to enhance organoleptic characteristics but also to benefit human health.

Genotypic variability in nutritional and functional attributes of blueberry varieties grown in northern-western Himalayas

Blueberry fruits are known for their high vitamin C, essential dietary fibre, antioxidant activity and anthocyanin pigments. Different blueberry varieties have been introduced in India but no attempt has been made for their nutritional profiling. Nutritional profiling of varieties helps us to know the unique varietal characters, which serves as a guideline for recommendation of a valuable variety for fresh consumption and/or processing. Therefore, the present study was conducted in eight different blueberry varieties such as 'Misty', 'Sharp Blue', 'Biloxi', 'Jewel', 'Gulf Coast', 'Blue Crop', 'Star', 'Legacy'. The results of the study revealed that all tested varieties differed significantly in physical attributes (10-berry weight, fruit firmness, roundness index, moisture content) and biochemical and functional attributes (ascorbic acid, total anthocyanin, total phenolic content, antioxidant activity, total sugars, organic acids) and mineral content. Regression analysis and Principal Component Analysis showed that antioxidant potential of blueberries was mainly contributed by phenolics followed by anthocyanins and ascorbic acid content. However for taste perception, fructose among sugars and succinic acid among sugars were the most influencing factors (p ≤ 0.05). Total phenolics and anthocyanins content were responsible for overall difference in functional attributes among the varieties. The attributes such as high fruit firmness, sensorial score, and appropriate shape and weight make 'Misty', the best variety for marketability and fresh consumption among all tested varieties.

dl-Malic acid as a component of α-hydroxy acids: effect on 2,4-dinitrochlorobenzene-induced inflammation in atopic dermatitis-like skin lesions in vitro and in vivo

Background: dl-Malic acid (dl-M) is used widely in cosmetic formulations as a pH-adjuster or as a preservative. dl-M is used as an exfoliator in the form of α-hydroxy acids. However, the role of dl-M in skin diseases (including atopic dermatitis (AD)) has not been studied deeply. We wished to reveal the effect of dl-M on AD induced by 2,4-dinitrochlorobenzene (DNCB) in Balb/c mice.Methods: The thickness and immune-cell infiltration into the dermis and epidermis were evaluated. Moreover, serum levels of cytokines, as well as expression of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) in tissue were measured in AD mice. We also studied the effect of dl-M on inflammatory mediators in a human keratinocyte (HaCaT) cell line. Results: The dl-M (high) group improved skin condition compared with the DNCB-treated group. The dl-M (high) group inhibited phosphorylation of MAPK and NF-κB in skin tissue. dl-M reduced serum levels of interleukin-4 and IgE. Finally, dl-M decreased the expression of thymus and activation-regulated chemokine, monocyte chemoattractant protein-1 and intercellular cell adhesion molecule induced by interferon-gamma/tumor necrosis factor-α in HaCaT cells. Discussion: These results suggest that dl-M can improve the skin conditions of AD mice.

Changes in Absolute Contents of Compounds Affecting the Taste and Nutritional Properties of the Flesh of Three Plum Species Throughout Development

The characteristics of plum fruits of three different species were investigated throughout their development (including over-ripening). The content of primary and secondary metabolites was expressed as amount per gram DW (dry weight) and per fruit in order to obtain information about the balance between their synthesis and dissimilation at different stages of fruit development. In all the plums, during the first stages of development, glucose was the most abundant sugar, whereas sucrose increased during ripening. There was no decrease in malate content per fruit before the commercial harvesting time of any of the plums, whereas a decrease was observed during over-ripening. In general, both the total phenol content and the contents of individual phenols in the flesh expressed on gram DW decreased throughout development, whereas their content per fruit increased, indicating that these decreases were due to a dilution effect arising from the expansion of the flesh. During the development of the flesh, the increase in the contents of the investigated metabolites per fruit shows that there was no net dissimilation of malate up to commercial harvest and of phenols throughout fruit development. Good correlations between the content of phenols to antioxidant activity were found. Shiro flesh, during the last part of fruit development, had lower total carbohydrate and polyphenol contents, lower antioxidant activities, and a higher malate content than the flesh of the other two genotypes.

Chemical and nutritional evaluation of major genotypes of nectarine (Prunus persica var nectarina) grown in North-Western Himalayas

Nectarine is an important stone fruit after plum and peach. The area under peach cultivation is now getting replaced by nectarine due to its fuzzless nature and high nutritive value. Nectarines are juicy, delicious fruits having low calorific value and have high antioxidant capacity. In India, its cultivation is confined to North-Western and North-Eastern Himalayas. In this study, five major nectarine cultivars growing in India namely, 'Silver Queen', 'Red Gold', 'Spring Bright', 'Independence' and 'Missourie' were harvested at commercial maturity and analyzed for various chemical and nutritional aspects. Our results showed that there were quantitative differences among the genotypes in different parameters analyzed. The predominant sugar in nectarine was fructose which was highest in 'Silver Queen' (14.48 mg 100 g^-1 FW) and lowest in 'Independence' (9.04 mg 100 g^-1 FW). Major organic acids were malic, succinic, citric and acetic acid. The highest malic acid content was recorded in 'Independence' (1.13 mg 100 g^-1 FW) and lowest in 'Red Gold' (0.61 mg 100 g^-1 FW). Nectarine genotypes chiefly contained phloridizin dihydrate and chlorogenic acid as the phenolic component. However, chlorogenic acid was highest in 'Spring Bright' (17.63 µg g^-1 FW) and lowest in 'Red Gold' (3.67 µg g^-1 FW). Similarly, a wider variability was recorded in major and minor mineral concentrations among the genotypes. Based on these observations, it can be concluded that among the major nectarine varieties cultivated in India, 'Silver Queen' have higher mineral nutrients than other varieties, and 'Spring Bright' have higher phenolics and antioxidants.

Characterization of Chinese white-flesh peach cultivars based on principle component and cluster analysis

The purpose of this study was to gain insights into the variations in quality characteristics of white-flesh peach fruits. Eighteen cultivars of north of China were investigated. The quality evaluation indicators, including color, physico-chemical and nutritional attributes were measured. Analysis of variance revealed that all the indicators showed significant differences among the cultivars, except edible rate. Principal Component Analysis (PCA) conducted to distinguish the indicators among cultivars, suggested that the most important factors affecting the peach quality could be reduced into nine principal components. Crude fiber content, glucose content, peel-b*, TA, moisture content, pulp-firmness, quinic content, shikimic content and edible rate could be regarded as the characteristic indicators for PC1, PC2, PC3,PC4, PC5, PC6, PC7, PC8 and PC9, respectively. Cluster analysis classified the different cultivars into five main groups on the basis of the measured quality evaluation indicators, and the results were in good accordance with PCA results.

Phenotypic characterization of qualitative parameters and antioxidant contents in peach and nectarine fruit and changes after jam preparation

BACKGROUND

Sugars and antioxidants in peaches contribute to fresh fruit quality and nutrition; however, information on widely grown cultivars and changes induced after peach jam preparation is limited. In the present study, colour, sugars and antioxidant parameters were determined in fruit and jam from 45 peach and nectarine cultivars.

RESULTS

Pronounced varietal differences were found in sorbitol (42-fold range), total phenolics (TPs) and antioxidant capacities (10- to 19-fold range). Sorbitol levels were greater in non-melting peach, followed by nectarine, and lower values were found in melting peach cultivars. Late-harvested peach and nectarine cultivars tended to have a higher soluble solid content and antioxidant potential. Cultivars with relatively high antioxidant contents produced darker and redder jams, containing more antioxidants, than the jam or the fruit from the other cultivars. Jam-TPs were reduced by 48% compared to fruit-TPs, with greater reduction being noted in high antioxidant cultivars. The most favorable jam organoleptic characteristics were found in 'Morsiani 90', 'Amiga', 'Romea' and 'Alirosada', as well as in non-melting compared to melting peach cultivars.

CONCLUSION

The best cultivars for each fruit flesh type and jam were identified. Peach jam could be an alternative substitute when fresh fruit is not available and when it is prepared with high antioxidant cultivars. © 2016 Society of Chemical Industry.

Characterization of autochthonous sweet cherry cultivars (Prunus avium L.) of southern Italy for fruit quality, bioactive compounds and antioxidant activity

BACKGROUND

Characterizing germplasm collections of autochthonous cultivars for fruit quality traits could be a successful approach for selection, improvement of organoleptic quality and levels of antioxidants of crop produce, and development of new market opportunities and coherent strategies for conservation and valorization. The aim of the study was the evaluation of fruit physicochemical traits as well as the content of bioactive compounds and the antioxidant capacity in 25 sweet cherry autochthonous cultivars.

RESULTS

Cultivars were a source of statistically significant variation for all evaluated traits. Notably, average fruit ascorbate levels ranged from 34.45 to 244.68 µg g^-1 fresh weight (FW) , total flavonoids from 1396.40 to 4694.75 µg quercetin equiv. g^-1 FW, monomeric anthocyanins from 4.80 to 360.90 µg g^-1 FW, and total antioxidant capacity from 1.53 to 2.58 nmol Trolox equiv. mg^-1 FW. Fruit profiling of eight cultivars by high-resolution mass spectrometry identified a total of eight different anthocyanins and twenty-five non-anthocyanin polyphenolic compounds - mostly coumaroylquinic acid and neochlorogenic acid.

CONCLUSION

Among the better-performing cultivars for fruit quality traits, Mulegnana Nera and Pagliarella shared high fruit levels of phenolics, flavonoids and antioxidant capacity. This is a forerunner work on the characterization of genetic resources, which is critical to researchers and breeders for exploitation of the genetic potential of cultivars and for their conservation. © 2016 Society of Chemical Industry.

Integrated analysis of multiomic data reveals the role of the antioxidant network in the quality of sea buckthorn berry

Berries of sea buckthorn, known as the "king of vitamin C," are abundant in antioxidants, have attractive colors, and are an excellent material with which to study the relationships between berry color, antioxidants, and berry quality. No study has yet determined the molecular basis of the relationship between sea buckhorn berries and their color and antioxidant levels. By using RNA-seq, LC-MS/MS, and LC/GC-MS technology and selecting red (darkest colored) and yellow (lightest colored) sea buckthorn berries at different development stages, this study showed that the red and yellow berry resulted from a higher ratio of lycopene to β-carotene and of β-carotene to lycopene content, respectively. The uronic acid pathway-a known animal pathway-in ascorbic acid synthesis was found in sea buckthorn berries, and the higher expression of UDP-glucuronosyltransferase in red berries was consistent with the higher content of ascorbic acid. In summary, multiomic data showed that the color of sea buckthorn berries is mainly determined by β-carotene and lycopene; red sea buckthorn berries were richer than yellow berries in antioxidants, such as carotenoids, flavonoids, and ascorbic acid; and the animal pathway might be operating in sea buckthorn.-He, C., Zhang, G., Zhang, J., Zeng, Y., Liu, J. Integrated analysis of multiomic data reveals the role of the antioxidant network in the quality of sea buckthorn berry.

Phenolic contents and bioactive potential of peach fruit extracts

Several cultivars of peach fruit (Prunus persica L.) were investigated. Their phenolic composition and concentration were assessed by LC-MS. Concentrations were calculated in mg per g of dry weight extract. Their antioxidant capacity (Folin-Ciocalteu, ORAC, DPPH, ABTS, PFRAP and ICA), inhibitory property against β-amyloid and α-synuclein fibril formation and protective capacity against Aβ-induced toxicity on PC12 cell lines (viability assessed by MTT assay and intracellular ROS production by DCFH-DA assay) were evaluated. Fifteen different phenolic compounds were identified and quantified. In particular, new isorhamnetin derivatives were identified. Phenolic contents were ranged between 19 and 82mg/g. Spring Belle extract had the highest content and Romea the lowest. Except for the ICA assay, a good correlation between phenolic content and the antioxidant capacities of peach fruit extracts was found, indicating that phenolic compounds are major contributors to their antioxidant capacity. Results indicate that the phenolic extract of peach cultivars inhibits Aβ and αS fibril formation and protects PC12 cell lines against Aβ-induced toxicity.