New high-quality peach (Prunus persica L. Batsch) genome assembly to analyze the molecular evolutionary mechanism of volatile compounds in peach fruits.

Peach (Prunus persica L. Batsch) is an economically important fruit crop worldwide. Although a high-quality peach genome has previously been published, Sanger sequencing was used for its assembly, which generated short contigs. Here, we report a chromosome-level genome assembly and sequence analysis of Chinese Cling, an important founder cultivar for peach breeding programs worldwide. The assembled genome contained 247.33 Mb with a contig N50 of 4.13 Mb and a scaffold N50 of 29.68 Mb, representing 99.8% of the estimated genome. Comparisons between this genome and the recently published one (Lovell peach) uncovered 685 407 single nucleotide polymorphisms, 162 655 insertions and deletions, and 16 248 structural variants. Gene family analysis highlighted the contraction of the gene families involved in flavone, flavonol, flavonoid, and monoterpenoid biosynthesis. Subsequently, the volatile compounds of 256 peach varieties were quantitated in mature fruits in 2015 and 2016 to perform a genome-wide association analysis. A comparison with the identified domestication genomic regions allowed us to identify 25 quantitative trait loci, associated with seven volatile compounds, in the domestication region, which is consistent with the differences in volatile compounds between wild and cultivated peaches. Finally, a gene encoding terpene synthase, located within a previously reported quantitative trait loci region, was identified to be associated with linalool synthesis. Such findings highlight the importance of this new assembly for the analysis of evolutionary mechanisms and gene identification in peach species. Furthermore, this high-quality peach genome provides valuable information for future fruit improvement.

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.

Phytochemicals from the flowers of Prunus persica (L.) Batsch: Anti-adipogenic effect of mandelamide on 3T3-L1 preadipocytes.

Flowers of Prunus persica (L.) Batsch (Rosaceae), known as peach blossoms, have been reported to exert anti-obesity effects by improving hepatic lipid metabolism in obese mice. However, little is known regarding the anti-adipogenic effects of the phenolic compounds isolated from P. persica flowers. This study investigated the inhibitory effects of compounds extracted from P. persica flowers (PPF) on adipogenesis in 3T3-L1 murine preadipocytes using adipogenic differentiation assays. Additionally, we compared the anti-adipogenic effects of the phenolic compounds isolated from PPF, such as prunasin amide (1), amygdalin amide (2), prunasin acid (3), mandelamide (4), methyl caffeate (5), ferulic acid (6), chlorogenic acid (7), benzyl α-l-xylpyranosyl-(1 â†’ 6)-ß-d-glucopyranoside (8), prunin (9), naringenin (10), nicotiflorin (11), astragalin (12), afzelin (13), and uridine (14), on adipogenesis in 3T3-L1 murine preadipocytes. PPF and compounds 4-7 and 10 significantly inhibited adipogenesis. Among them, mandelamide (4) exhibited the maximum inhibitory activity with an IC50 of 36.04 ± 1.82 µM. Additionally, mandelamide downregulated the expression of key adipogenic markers, such as extracellular signal-regulated kinase, c-Jun-N-terminal kinase, P38, CCAAT/enhancer-binding protein α, CCAAT/enhancer-binding protein ß, peroxisome proliferator activated receptor γ, and glucocorticoid receptor. These results indicate that mandelamide is an active ingredient of PPF possessing anti-obesity properties.

An ultra-sensitive electrochemiluminescence probe based on ternary nanocomposite and boron nitride quantum dots for detection of diazinon.

A new enzyme-free electrochemiluminescence (ECL) pesticide sensor was fabricated based on ternary nanocomposite of ruthenium nanoparticles/silver nanoparticles/graphene oxide on the surface of glassy carbon electrode for ultratrace determination of diazinon. Due to some drawbacks of enzyme-based sensors such as enzyme instability at elevated temperature, humidity, changes of pH, and high price of the enzyme, the use of enzyme was omitted in the construction of the developed sensor. The silver nanoparticles with good electrocatalytic proficiency as a signal improving agent and tris(2,2bipyridine) ruthenium(II) as a popular luminophore were uniformly deposited on the surface of the prepared graphene oxide/GC electrode at nanoscale. Boron nitride quantum dots as an efficient co-reactant created the superior efficiency in amplifying the ECL intensity of the ruthenium-based ECL system. The prepared electrode was utilized for the detection of diazinon via the robust ECL method. For the present sensor, a wide linear dynamic range and low detection limit were achieved (3.0 × 10-15 to 6.5 × 10-9 M and 9.5 × 10-16 M, respectively). The obtained results confirmed the fabrication of the robust ECL probe, which is characterized by the cooperative effect of silver nanoparticles and the attached luminophore species. The main advantage of the presented sensor was that the samples could be diluted so that the effect of the interference species was negligible. Due to excellent properties toward accurate determination of diazinon, the ECL sensor as a new practical platform was applied for quantitative detection of diazinon in some real samples.

Construction of an electrochemical sensor with graphene aerogel doped with ZrO2 nanoparticles and chitosan for the selective detection of luteolin.

A simple, fast and sensitive method for the detection of luteolin is proposed based on the chitosan/reduced graphene oxide aerogel with dispersed ZrO2 nanoparticles modified glassy carbon electrode (ZrO2/CS/rGOA-GCE) as an electrochemical sensor. The ZrO2/CS/rGOA composite was prepared by one pot synthesis from a mixture of GO, CS and zirconyl chloride octahydrate, and subsequently be freeze-dried. Scanning electron microscope images showed a typical thin, wrinkled and fluctuant morphology of graphene nanosheets and the polymerized CS and ZrO2 nanoparticles deposited on the surface of rGOA. Cyclic voltammetry and differential pulse voltammetry were used to measure the electrochemical response of ZrO2/CS/rGOA composite-based biosensor towards luteolin at the working potential window (-0.8-0.8 V). The improved performance of this biosensor was attributed to efficient electron transfer and large surface area of 3D rGOA, and high specific activity of Zr towards adjacent hydroxyl groups. Under optimized conditions, the analytical performance of this method towards luteolin was investigated with a detection limit of 1 nM and a linear range from 5 nM to 1000 nM.. Finally, the ZrO2/CS/rGOA-GCE electrochemical method coupled with solid phase extraction was used for the detection of luteolin in real samples. Recoveries of  spiked samples with different concentrations were in the range 78.6-103.3% with a relative RSD lower than 12.0%. Graphical abstract Schematic representation of the preparation of the ZrO2 nanoparticles and chitosan doped graphene aerogel modified electrode. The electrode was employed for the detection of luteolin coupled with the solid-phase extraction technique.

GC-MS Metabolic Profile and α-Glucosidase-, α-Amylase-, Lipase-, and Acetylcholinesterase-Inhibitory Activities of Eight Peach Varieties.

The inhibition of certain digestive enzymes by target food matrices represents a new approach in the treatment of socially significant diseases. Proving the ability of fruits to inhibit such enzymes can support the inclusion of specific varieties in the daily diets of patients with diabetes, obesity, Alzheimer's disease, etc., providing them with much more than just valuable micro- and macromolecules. The current study aimed atidentifying and comparing the GC-MS metabolic profiles of eight peach varieties ("Filina", "Ufo 4, "Gergana", "Laskava", "July Lady", "Flat Queen", "Evmolpiya", and "Morsiani 90") grown in Bulgaria (local and introduced) and to evaluate the inhibitory potential of their extracts towards α-glucosidase, α-amylase, lipase, and acetylcholinesterase. In order to confirm samples' differences or similarities, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were also applied to the identified metabolites. The results provide important insights into the metabolomic profiles of the eight peach varieties and represent a first attempt to characterize the peels of the peach varieties with respect to α-glucosidase-, α-amylase-, lipase-, and acetylcholinesterase-inhibitory activities. All of the studied peach extracts displayed inhibitory activity towards α-glucosidase (IC50: 125-757 mg/mL) and acetylcholinesterase (IC50: 60-739 mg/mL), but none of them affected α-amylase activity. Five of the eight varieties showed inhibitory activity towards porcine pancreatic lipase (IC50: 24-167 mg/mL). The obtained results validate the usefulness of peaches and nectarines as valuable sources of natural agents beneficial for human health, although further detailed investigation should be performed in order to thoroughly identify the enzyme inhibitors responsible for each activity.

Application of visible/NIR spectroscopy for the estimation of soluble solids, dry matter and flesh firmness in stone fruits.

BACKGROUND: Soluble solids concentration (SSC), dry matter concentration (DMC) and flesh firmness (FF) are important fruit quality parameters in stone fruits. This study investigated the ability of a commercial visible/near-infrared (NIR) spectrometer to determine SSC, DMC and FF in nectarine, peach, apricot and Japanese plum cultivars at harvest. The work was conducted in summer 2019/2020 on 14 stone fruit cultivars at Tatura, Australia. Two sub-samples of 100 fruit each were collected before and after commercial maturity (± 5 days) in order to maximize sample variability. RESULTS: Partial least square (PLS) regression models based on the second derivative of the absorbance in the 729-975 nm spectral region proved accurate for the prediction of SSC and DMC (R2 CV > 0.750). Only the model generated for SSC in 'Golden May' apricot was less precise compared to other cultivars. No visible/NIR models were accurate enough to predict FF in the cultivars under study (R2 CV < 0.750). CONCLUSION: This study demonstrated that the visible/NIR spectrometer was a reliable tool to monitor SSC and DMC in stone fruits at harvest but proved less useful for FF estimation. These results highlight the potential of visible/NIR spectrometry to evaluate stone fruit quality both in situ pre-harvest and in the laboratory after harvest. © 2020 Society of Chemical Industry.

Jasmonic acid and salicylic acid induce the accumulation of sucrose and increase resistance to chilling injury in peach fruit.

BACKGROUND: Salicylic acid (SA) and jasmonic acid (JA) can both enhance resistance of chilling injury (CI) in cold-storage peach fruit, but the regulatory mechanisms involved and whether there is a coordinated regulation between them is unclear. In this study, postharvest peach fruit were treated with an aqueous SA solution for 15 min or an aqueous JA solution for 30 s before storage at 4 °C for 35 days. RESULTS: SA and JA treatments both delayed and reduced development of internal browning (a symptom of CI) and induced the accumulation of hydrogen peroxide and sucrose. The SA and JA also reduced catalase and peroxidase activities, which are involved in hydrogen peroxide generation. The SA and JA treatments significantly regulated the transcript abundance of genes related to sucrose biosynthesis and degradation consistent with the observed increase in sucrose content. CONCLUSION: These results intimate that JA and SA may be involved in coordinating the alleviation of CI via increased accumulation of sucrose. © 2021 Society of Chemical Industry.

Residual behavior and dietary intake risk assessment of flonicamid, dinotefuran and its metabolites on peach trees.

BACKGROUND: Flonicamid and dinotefuran are widely applied to control pests and diseases in various economic crops arousing much public concerns about the potential risk to human health. In this study, the multi-determination and residual behavior of flonicamid-dinotefuran mixture on peach trees were investigated. The chronic risk of long-term dietary intake for Chinese consumers was evaluated. RESULTS: An optimized QuEChERS method combined with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis for simultaneous determination of flonicamid, dinotefuran and its metabolites was established to analyze the residual dissipation and terminal residues in peach matrices. The results demonstrated that (i) a satisfactory linearity relationship with the detector response and the correlation coefficient R2 > 0.999, the average recoveries of these four analytes ranged from 94 to 108%, the relative standard deviation was between 1.0% and 8.8%, and the limit of the quantitation was 0.02 mg kg-1 ; (ii) the dissipation behaviors of flonicamid and dinotefuran followed with the first-order dynamic kinetics model, and the half-lives were 6.9-12.4 days and 8.1-15.1 days, respectively; (iii) the recommended preharvest interval (PHI) was 21 days, the risk quotient (RQ) values of flonicamid and dinotefuran were 16.6 and 20.7%, respectively, which were significantly less than 100%. CONCLUSION: The established analytical method met the detection requirement in terms of sensitivity, accuracy, and precision. Additionally, the results indicated that the potential dietary intake risk of the flonicamid-dinotefuran mixture on peach trees was negligible. This work can be utilized in the safe and responsible use of flonicamid-dinotefuran mixture and provide guidance for establishing its maximum residue limit (MRL) in China. © 2021 Society of Chemical Industry.

Cytotoxic, antimicrobial and nitric oxide inhibitory activities of supercritical carbon dioxide extracted Prunus persica leaves.

Different parts of Prunus persica as fruits, flowers, leaves and kernels have been consumed with dietary and therapeutic purposes traditionally. During fruit production, remarkable amount of leaves which can hold important bioactive groups as phenolics, have been left unutilized. The aim of this study was to investigate cytotoxic, antimicrobial and nitric oxide inhibitory activities of supercritical carbondioxide extracts of Prunus persica leaves. Among studied cell lines, supercritical carbon dioxide extract which was processed at 150 bar, 60 °C, and 6% co-solvent ethanol, exhibited remarkable cytotoxic activity against HeLa, MPanc-96 and MCF-7 cell lines with IC50 values of 12.22 µg/ml, 28.17 µg/ml and 35.51 µg/ml respectively, whereas IC50 value of conventional solvent extract was above 50 µg/ml. Minimum inhibitory concentration values determined for antibacterial and antifungal activities against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Enterococcus faecium and Candida albicans were found as 62.50 µg/ml. Strong nitric oxide inhibition was achieved with IC50 of 9.30 µg/ml. The promising results revealed that Prunus persica leaves may have remarkable potential as supplement both for drug and food industries. This study is the first report revealing cytotoxic, antimicrobial and nitric oxide inhibitory activity of supercritical carbon dioxide extract of Prunus persica leaves.

Rapid and Non-Destructive Detection of Compression Damage of Yellow Peach Using an Electronic Nose and Chemometrics.

The rapid and non-destructive detection of mechanical damage to fruit during postharvest supply chains is important for monitoring fruit deterioration in time and optimizing freshness preservation and packaging strategies. As fruit is usually packed during supply chain operations, it is difficult to detect whether it has suffered mechanical damage by visual observation and spectral imaging technologies. In this study, based on the volatile substances (VOCs) in yellow peaches, the electronic nose (e-nose) technology was applied to non-destructively predict the levels of compression damage in yellow peaches, discriminate the damaged fruit and predict the time after the damage. A comparison of the models, established based on the samples at different times after damage, was also carried out. The results show that, at 24 h after damage, the correct answer rate for identifying the damaged fruit was 93.33%, and the residual predictive deviation in predicting the levels of compression damage and the time after the damage, was 2.139 and 2.114, respectively. The results of e-nose and gas chromatography-mass spectrophotometry (GC-MS) showed that the VOCs changed after being compressed-this was the basis of the e-nose detection. Therefore, the e-nose is a promising candidate for the detection of compression damage in yellow peach.

Nitrogen fertilization rates in a subtropical peach orchard: effects on tree vigor and fruit quality.

BACKGROUND: Nitrogen is a key component of crop production and is commonly related to increases in yield and fruit size. The N fertilization rates used for low-chill peach cultivars were adapted from other peach production regions, where environmental and soil conditions are different. The growth and production as well as the effect on fruit physical and compositional attributes of two low-chill peach cultivars - 'TropicBeauty' (TB) and 'UFSharp' (UFS) - with five different N fertilization rates (0 (N0), 45 (N1), 90 (N2), 179 (N3) and 269 (N4) kg ha-1 applied each year from 2011 to 2017) were examined. RESULTS: Peach trees under higher N rates had higher pruning weights compared to the lower N0 or N1 rates. Yield was only affected in 2017 for the two cultivars tested. Physical attributes were inconsistently affected by N. Fruit from the higher N rates had lower a* value (more green) than fruit from the trees under low or zero N. While fruit firmness was not affected by N, fruit from trees under zero/low N had higher total soluble solids in some years. CONCLUSION: Considering that N is recycled in the trees, being retained and reused each season to resume growth, it is important to address peach orchard fertilization based on peach tree N status. The results of this experiment show that an increase in N beyond what is required for tree maintenance does not increase yield. In addition, reducing N does not strongly affect fruit quality, although the color and soluble solids results suggest that lower N rates may advance fruit maturation. © 2019 Society of Chemical Industry.

Synthesis of polyhedral gold nanostars as surface-enhanced Raman spectroscopy substrates for measurement of thiram in peach juice.

Rapid detection of food contaminants using novel analytical methods in combination with nanomaterials has received much attention. This study aimed to synthesize polyhedral gold nanostars (AuNS) with multi-angled corners and develop a surface-enhanced Raman spectroscopy (SERS) method coupled with AuNS to detect pesticide residues in juice products. AuNS are multi-branched three-dimensional metal nanostructures with rough surface features which can induce surface plasmon resonance. A facile synthesis of AuNS was achieved using a two-step method and as-prepared AuNS had much cleaner surfaces than gold nanoparticles. A Raman reporter molecule (4-aminothiophenol) was used to evaluate the performance of the SERS method, yielding fingerprint-like Raman spectra and the sensitivity of the SERS method could reach 10 ppb (µg kg-1). SERS coupled with AuNS was used to detect thiram residues in peach juice and the detection limit was 50 ppb, and is 100 times more sensitive than using normal gold nanoparticles. These results demonstrate that AuNS are excellent substrates for SERS measurement, which has great potential for rapid detection of chemical contaminants in food products.

Evaluation of Anti-inflammatory, Antinociceptive, and Antipyretic Activities of Prunus persica var. nucipersica (Nectarine) Kernel.

Nectarine (Prunus persica var. nucipersica) is a worldwide appreciated edible subspecies, with a high nutritional value and benefits on human health due to its phenolic content. Despite the large consumption of the fruit, the potential use of its kernel is poorly studied. Herein, the potential pharmacological activities and the phenolic constituents of an alcoholic extract of kernel nectarine fruits were investigated. Administering nectarine kernel extract (50 and 100 mg/kg, respectively) in rats reduced paw edema after carrageenan injection by 11 and 47% in 1 h, 24 and 33% in 2 h, and 23 and 32% in 4 h, when compared to the controls. At the higher dose (100 mg/kg), nectarine kernel extract increased the reaction time in the hot-plate model and produced a significant decrease in the rectal temperature of the pyretic rats, while both doses produced 52 and 59% of writhing inhibition compared to the control group. Total polyphenolic (55.91 ± 5.78 mg/g) and flavonoid (29.89 ± 0.55 mg/g) content indicated that the extract is a promising source of these constituents. HPLC-ESI-MS/MS analysis demonstrated the presence of flavonoids, such as naringenin and apigenin glycosides. The cyanogenic glycosides amigdalin and prunasin were also detected. These results highlight the anti-inflammatory, analgesic, and antipyretic activities of nectarine kernel alcoholic extract, together with significant phenolic content, promoting its exploitation as a source of bioactive molecules.

The anti-proliferative effect of apricot and peach kernel extracts on human colon cancer cells in vitro.

BACKGROUND: Colorectal malignant neoplasms is one of the leading causes of death in both men and women in the developed world and the incidence has recently increased markedly in South Africa. Studies have highlighted the beneficial effects of Amygdalin, a cyanogenic compound found in both peach and apricot kernels, in its ability to suppress the development of colon cancer. The focus of this study was to investigate the potential anti-proliferative properties of various apricot and peach kernels extractions from South Africa and China and to monitor alterations in cell cycle kinetics in colon cancer cells. METHODS: Studies were conducted on HT-29 colon cancer cells. The interactive role of three different kernel extractions on the modulation of cell proliferation, apoptosis and cell cycle progression was monitored over 24, 48 and 72 h periods. RESULTS: After 24 h, all extracts of the South African apricot kernels had a dose related bi-phasic proliferative effect on the HT-29 cells. It stimulated cell proliferation at the lowest and highest concentrations while at 500 µg/mL it inhibited cell proliferation. In contrast, after 72 h, the low concentration inhibited cell proliferation while the 500 µg/mL extracts stimulated cell proliferation. Morphological changes were observed in cells incubated with Chinese kernel extracts after 24 h and South African kernel treatment (1000 µg/mL) after 72 h. A possible intra-S-phase block after 24 and 48 h exposure to South African hydrophilic kernel extracts was observed. This transient block that is more concerned with tolerating and accommodating damage during replication rather than repairing it, could explain the initial anti-proliferative effects observed after 24 h exposure to the various Chinese kernel extract concentrations. CONCLUSION: Abrogation of the block by exhaustion of the cyanide production, most likely allowed the cells to resume the cell cycle and continue into mitosis, whereas low ATP levels caused by the presence of amygdalin in the kernels, can also cause the induction of pycnosis or necrosis. These results highlight the possible mechanisms of growth inhibition by amygdalin containing extracts and may contribute towards the development of dietary anti-cancer therapies.

ß-Fructofuranosidase and ß -D-Fructosyltransferase from New Aspergillus carbonarius PC-4 Strain Isolated from Canned Peach Syrup: Effect of Carbon and Nitrogen Sources on Enzyme Production.

ß-fructofuranosidase (invertase) and ß-D-fructosyltransferase (FTase) are enzymes used in industrial processes to hydrolyze sucrose aiming to produce inverted sugar syrup or fructooligosaccharides. In this work, a black Aspergillus sp. PC-4 was selected among six filamentous fungi isolated from canned peach syrup which were initially screened for invertase production. Cultivations with pure carbon sources showed that invertase and FTase were produced from glucose and sucrose, but high levels were also obtained from raffinose and inulin. Pineapple crown was the best complex carbon source for invertase (6.71 U/mL after 3 days of cultivation) and FTase production (14.60 U/mL after 5 days of cultivation). Yeast extract and ammonium chloride nitrogen sources provided higher production of invertase (6.80 U/mL and 6.30 U/mL, respectively), whereas ammonium nitrate and soybean protein were the best nitrogen sources for FTase production (24.00 U/mL and 24.90 U/mL, respectively). Fermentation parameters for invertase using yeast extract were Y P/S = 536.85 U/g and P P = 1.49 U/g/h. FTase production showed values of Y P/S = 2,627.93 U/g and P P = 4.4 U/h using soybean protein. The screening for best culture conditions showed an increase of invertase production values by 5.10-fold after 96 h cultivation compared to initial experiments (fungi bioprospection), while FTase production increased by 14.60-fold (44.40 U/mL) after 168 h cultivation. A. carbonarius PC-4 is a new promising strain for invertase and FTase production from low cost carbon sources, whose synthesized enzymes are suitable for the production of inverted sugar, fructose syrups, and fructooligosaccharides.

Peach Kernel Oil Downregulates Expression of Tissue Factor and Reduces Atherosclerosis in ApoE knockout Mice.

Atherosclerosis is the pathological process in arteries due to the plaque formation that is responsible for several diseases like heart disease, stroke and peripheral arterial disease. In this study, we performed in vitro and in vivo assays to evaluate the potential anti-atherosclerosis activity of peach kernel oil. For the in vitro assay, we incubated human umbilical vein endothelial cells (HUVEC) with tumor necrosis factor-α (TNF-α) to induce tissue factors (TF, an essential mediator of hemostasis and trigger of thrombosis) elevation. We found that TNF-α-induced TF elevation was suppressed by peach kernel oil in a dose-dependent manner at both mRNA and protein levels. Peach kernel oil can significantly improve HUVEC viability, protect the endothelial cells, which achieved the goal of prevention of thrombotic diseases. For the in vivo assay, we investigated the effect and mechanism of peach kernel oil on preventing atherosclerotic lesion formation in ApoE knockout mice. Results show that peach kernel oil could reduce total cholesterol, triglyceride, low-density lipoprotein cholesterol levels, elevate the high-density lipoprotein cholesterol level in serum, and reduce the area of the aortic atherosclerotic lesions in high-fat diet fed ApoE knockout mice. Moreover, peach kernel oil treatment can significantly down regulate the expression of TF protein to inhibit the formation of atherosclerotic plaque. In conclusion, peach kernel oil may be a potential health food to prevent atherosclerosis in cardiovascular diseases.

Combined Analysis of Primary Metabolites and Phenolic Compounds to Authenticate Commercial Monovarietal Peach Purees and Pear Juices.

Here we authenticated single-varietal peach purees and pear juices on the basis of primary metabolite and phenolic compound analysis by Proton Nuclear Magnetic Resonance (1H-NMR) and Ultra Performance Liquid Chromatography coupled to Photodiode Array and Tandem Mass Spectrometry (UPLC-PDA-MS/MS), respectively. After suitable preprocessing, the 1H-NMR and chromatographic data were evaluated by principal component analysis (PCA). The PCA combining data from primary metabolites and phenolic compounds allowed the separation of the clusters in all cases, allowing discrimination of processed and unprocessed peach purees, both separately and pooled. The PCA of primary metabolites allowed the cluster separation of purees of distinct peach varieties but not between processed and non-processed purees. The PCA of phenolic compounds allowed better cluster separation than of primary metabolites. For pear juices, both PCA approaches allowed satisfactory discrimination of Alejandrina, Conference, and Blanquilla cultivars. These approaches may help to better control cultivar authenticity in fruit products. It could therefore contribute to the development of a process to achieve products characterized by a quality characteristic of a given cultivar.

Comparison of Phytochemical Differences of the Pulp of Different Peach [Prunus persica (L.) Batsch] Cultivars with Alpha-Glucosidase Inhibitory Activity Variations in China Using UPLC-Q-TOF/MS.

In order to fully understand the variation of the fruit alpha-glucosidase inhibitory activity-related phytochemical basis in the Chinese peach [Prunus persica (L.) Batsch], mature fruit from 33 cultivars was used for the investigation of fruit phenolic phytochemical attributes, including total phenolics, flavonoids, anthocyanins, and procyanidins, as well as the alpha-glucosidase inhibitory activity in vitro. Alpha-glucosidase inhibitory activity varied significantly among tested peach cultivars and was strongly correlated with total phenolics, total procyanidins, and total flavonoids. Untargeted UPLC-Q-TOF/MS-based metabolomics were used to comprehensively discriminate between peaches with different inhibitory activity on alpha-glucosidase. Principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) were used for this process. Twenty-three differential compounds were identified between peach cultivars with high and low alpha-glucosidase inhibitory activity, and nine, including procyanidin C1, procyanidin trimer isomer 1, procyanidin trimer isomer 2, procyanidin B1, procyanidin dimer, epicatechin-epicatechin-epicatechin, phloridzin, kaempferol 3-(2'',6''-di-(E)-p-coumarylglucoside), and luteolin 3'-methyl ether 7-malonylglucoside, were identified as marker compounds responsible for the discrimination. Overall, variations in metabolites in peach pulp reflect the diversity in peach germplasm, and these nine compounds are good candidate markers for future genetic breeding of peach fruit with high alpha-glucosidase inhibitory activity.

Evaluation and modelling of osmotic pre-treatment of peach using alternative agents in a multiple-component solution.

BACKGROUND: Peach is a perishable fruit of great importance for the Greek food export market which is prone to rapid deterioration after harvesting. Its short shelf life can be substantially prolonged by applying an appropriate osmotic dehydration (OD) pre-treatment, which is a mild, non-thermal procedure. The aim of this study was to describe mass transfer and quality retention induced by the OD process. RESULTS: Peach pieces were immersed in tertiary solutions of glycerol, erythritol, steviol glucosides and mineral salts at pre-selected OD conditions (25-45 °C for 3-240 min, wfruit /wsolution = 1:5). Water loss (WL), solid gain (SG), water activity (aw ) as well as representative quality indices (colour, texture) were measured during OD, showing that osmotically dehydrated peach presented significant aw reduction (from 0.97 to 0.88) combined with quality retention. CONCLUSION: This research showed that OD can be an effective pre-processing step in the production of intermediate moisture novel products. A second-degree polynomial model was developed describing adequately the effect of OD time and temperature and glycerol concentration on WL, SG, aw , colour and texture of osmotically dehydrated peach, and analysis of variance was applied to identify those factors that significantly affect the aforementioned parameters. It was concluded that OD using alternative osmotic agents is an efficient method with respect to product colour and texture retention, allowing for the production of novel products with extended shelf life. © 2018 Society of Chemical Industry.