Accumulation of Antioxidants in Apricot Fruit through Ripening: Characterization of a Genotype with Enhanced Functional Properties

Development, characterization and use of rosemary essential oil loaded water-chestnut starch based nanoemulsion coatings for enhancing post-harvest quality of apples var. Golden delicious

The study aimed at evaluating the influence of water-chestnut starch-based coatings loaded with rosemary essential oil (REO) at concentrations of 0.10%, 0.25% and 0.50% (w/v) on postharvest cold storage stability of apple var. Golden delicious for 120 days. Average droplet diameter of nanoemulsions was in range of 315-450 nm and it increased with increase in the REO concentration. Minimum weight loss was observed in fruits treated with coating material containing 0.50% REO. Samples coated with starch+0.50% REO exhibited highest firmness value of 68.22 ± 1.02 N under controlled atmosphere storage (CAS). Anthocyanins, ascorbic acid, total phenolic content and antioxidant activity were retained in all samples coated with formulated emulsion. Antifungal assay against Pencillium expansum indicated that 0.50% REO had maximum antifungal activity. Increase in REO concentration from 0.10 to 0.50% in starch coating formulations resulted in reduced lesion diameter in coated samples under both the storage conditions. Lesion diameter (LD) was found highest in control (39.40 ± 0.20 mm) under ambient conditions. Coated fruit samples showed a significant (p≤0.05) reduction in LD under both the ambient and CAS conditions however, more pronounced effect was reported under CAS. Fruits coated with edible coatings enriched with different REO concentrations under CAS exhibited significantly (p≤0.05) lower chilling injury index (ST+0.50%REO < ST+0.25%REO<0.10%REO) compared to control.

Metabolomic and transcriptomice analyses of flavonoid biosynthesis in apricot fruits

Introduction

Flavonoids, as secondary metabolites in plants, play important roles in many biological processes and responses to environmental factors.

Methods

Apricot fruits are rich in flavonoid compounds, and in this study, we performed a combined metabolomic and transcriptomic analysis of orange flesh (JN) and white flesh (ZS) apricot fruits.

Results and discussion

A total of 222 differentially accumulated flavonoids (DAFs) and 15855 differentially expressed genes (DEGs) involved in flavonoid biosynthesis were identified. The biosynthesis of flavonoids in apricot fruit may be regulated by 17 enzyme-encoding genes, namely PAL (2), 4CL (9), C4H (1), HCT (15), C3'H (4), CHS (2), CHI (3), F3H (1), F3'H (CYP75B1) (2), F3'5'H (4), DFR (4), LAR (1), FLS (3), ANS (9), ANR (2), UGT79B1 (6) and CYP81E (2). A structural gene-transcription factor (TF) correlation analysis yielded 3 TFs (2 bHLH, 1 MYB) highly correlated with 2 structural genes. In addition, we obtained 26 candidate genes involved in the biosynthesis of 8 differentially accumulated flavonoids metabolites in ZS by weighted gene coexpression network analysis. The candidate genes and transcription factors identified in this study will provide a highly valuable molecular basis for the in-depth study of flavonoid biosynthesis in apricot fruits.

Antioxidant Properties of Pulp, Peel and Seeds of Phlegrean Mandarin (Citrus reticulata Blanco) at Different Stages of Fruit Ripening

In this work, we assess the potential of waste products of Phlegrean mandarin (Citrus reticulata Blanco), namely seeds and peel, to be reutilized as a source of bioactive compounds beneficial for the human diet. Starting from the evidence that the by-products of this specific cultivar are the most powerful sources of antioxidants compared to pulp, we have investigated if and how the bioactive compounds in peel and seeds may be affected by fruit ripening. Three stages of fruit ripening have been considered in our study: unripe fruits = UF, semi-ripe fruits = SRF, ripe fruits = RF. The overall results indicated that RF showed the highest concentration of antioxidants. Among fruit components, peel was the richest in total antioxidant capacity, total polyphenol content, total flavonoids, total chlorophylls and carotenoids, while seeds exhibited the highest concentration of total condensed tannins and ascorbic acid. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay indicates the occurrence, in peel extracts, of 28 phenolic compounds, mainly flavonoids (FLs); in seeds, 34 derivatives were present in the first stage (UF), which diminish to 24 during the ripening process. Our data indicated that the content of phytochemicals in citrus strongly varies among the fruit components and depends on the ripening stage. The higher antioxidant activity of peel and seeds, especially in RF, encourage a potential use of by-products of this specific citrus cultivar for industrial or pharmacological applications. However, to maximize the occurrence of desired bioactive compounds, it is important also to consider the ripening stage at which fruits must be collected.

Investigating the effect of oxalic acid and salicylic acid treatments on the post-harvest life of temperate grown apricot varieties (Prunus armeniaca) during controlled atmosphere storage

This study aimed at investigating the influence of different postharvest treatments with oxalic acid (OA) and salicylic acid (SA) on quality attributes and postharvest shelf life of temperate grown apricot varieties stored under controlled atmosphere (CA) storage conditions. After each treatment was given, the samples were stored in CA store maintained at a temperature of 0 °C, 90 ± 5% relative humidity, 5% oxygen and 15% carbon dioxide for 30 days. Results indicated that both OA and SA treatments significantly (p ≤ 0.05) retained total soluble solids, titratable acidity, color profile, ascorbic acid content and total phenolic content of apricot varieties and had a positive effect on antioxidant activity and texture of samples compared to control. However, carotenoid content was found to be higher in control. Both the treatments reduced chilling injury index, weight loss and decay percentage of samples. Moreover, it was found that SA treatment was the most effective treatment in maintaining visual color of apricots while OA maintained fruit firmness and effectively decreased the decay percentage and chilling injury index of apricot varieties. In conclusion, it was found that both OA and SA have the potential to extend storage life of apricots and maintain quality attributes of the crop during CA storage.

High-Throughput Screening and Characterization of Phenolic Compounds in Stone Fruits Waste by LC-ESI-QTOF-MS/MS and Their Potential Antioxidant Activities

Stone fruits, including peach (Prunus persica L.), nectarine (Prunus nucipersica L.), plum (Prunus domestica L.) and apricot (Prunus armeniaca L.) are common commercial fruits in the market. However, a huge amount of stone fruits waste is produced throughout the food supply chain during picking, handling, processing, packaging, storage, transportation, retailing and final consumption. These stone fruits waste contain high phenolic content which are the main contributors to the antioxidant potential and associated health benefits. The antioxidant results showed that plum waste contained higher concentrations of total phenolic content (TPC) (0.94 ± 0.07 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC) (0.34 ± 0.01 mg quercetin equivalents (QE)/g), while apricot waste contained a higher concentration of total tannin content (TTC) (0.19 ± 0.03 mg catechin equivalents (CE)/g) and DPPH activity (1.47 ± 0.12 mg ascorbic acid equivalents (AAE)/g). However, nectarine waste had higher antioxidant capacity in ferric reducing-antioxidant power (FRAP) (0.98 ± 0.02 mg AAE/g) and total antioxidant capacity (TAC) (0.91 ± 0.09 mg AAE/g) assays, while peach waste showed higher antioxidant capacity in 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay (0.43 ± 0.09 mg AAE/g) as compared to other stone fruits waste. Qualitative and quantitative phenolic analysis of Australian grown stone fruits waste were conducted by liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and HPLC-photodiode array detection (PDA). The LC-ESI-QTOF-MS/MS result indicates that 59 phenolic compounds were tentatively characterized in peach (33 compounds), nectarine (28), plum (38) and apricot (23). The HPLC-PDA indicated that p-hydroxybenzoic acid (18.64 ± 1.30 mg/g) was detected to be the most dominant phenolic acid and quercetin (19.68 ± 1.38 mg/g) was the most significant flavonoid in stone fruits waste. Hence, it could be concluded that stone fruit waste contains various phenolic compounds and have antioxidant potential. The results could support the applications of these stone fruit wastes in other food, feed, nutraceutical and pharmaceutical industries.

Temporal Changes and Correlations between Quality Loss Parameters, Antioxidant Properties and Enzyme Activities in Apricot Fruit Treated with Methyl Jasmonate and Salicylic Acid during Cold Storage and Shelf-Life

The apricot storability is one of the largest challenges, which the apricot industry has to face all over the world; therefore, finding options for prolonging fruit quality during cold storage (CS) and shelf-life (SL) will help to decrease postharvest losses of apricot. The aim of this apricot fruit work was to study the temporal changes and correlations of 10 quality parameters (quality losses, antioxidant properties and enzyme activities) in the postharvest treatments of methyl jasmonate (MeJA) and salicylic acid (SA) under 1 °C CS (7, 14 and 21 days) and 25 °C SL (4 and 8 days after the 21-day CS) treatments. MeJA and SA significantly decreased the quality loss of chilling injury (CI) and fruit decay (FD) at all dates for both storage conditions. MeJA- and SA-treated fruits increased total antioxidant capacity (TAC), total soluble phenolic compounds (TSPC) and carotenoids contents (TCC) at all dates of both storage treatments. In contrast, the ascorbic acid content (AAC) increased only until days 14 and 4 in the CS and SL treatments, respectively. Among enzyme activity parameters, the activities of phenylalanine ammonia-lyase (PAL), peroxidase and superoxide dismutase (SOD) were significantly increased in the MeJA and SA treatments in all dates of both storage treatments. Catalase (CAT) activity increased in the SA and control treatments, while it decreased in the MeJA treatment in both storage conditions. In both the MeJA and the SA treatments, six pair-variables (FD vs. CI, PAL vs. CAT, PAL vs. SOD, TAC vs. SOD, TAC vs. FD, and AAC vs. CI) were significant in Pearson correlation and regression analyses among the 45 parameters pairs. Principal component analyses explained 89.3% of the total variance and PC1 accounted for 55.6% of the variance and correlated with the CI, FD, TAC, TSPC, TCC, PAL and SOD, indicating strong connections among most parameters. In conclusion, MeJA and SA are practically useful and inexpensive techniques to maintain quality attributes of CI, FD, TAC, TSPC, TCC, PAL, POD and SOD in apricot fruit during both CS and SL conditions.

Phytochemical profiling, antioxidant and HepG2 cancer cells' antiproliferation potential in the kernels of apricot cultivars

Phytochemical composition, in vitro antioxidant and antiproliferative activity against HepG2 cells were studied in the kernels of apricot cultivars grown in the northern areas of Pakistan. Relatively, the kernel of Habbi cultivar/AP-12 depicted significant potential to scavenge DPPH and ABTS+ free radicals as well as oxygen radical absorbance capacity along with highest contents of total flavonoids, phenolics, chlorogenic and syringic acids on dry weight basis. The average concentration of quercetin ranged 0.072-1.343 mg/100 g, and of EGCG from 0.713 to 6.521 mg/100 g with maximum concentration in Hulappa/AP-3 and Kho Chali-Khatta 3/AP-17, respectively. Amygdalin content was highest (1145 mg/100 g) in the kernel of Balaani/AP-14. Highest inhibition of HepG2 cells was found in the kernel of Waflu Chuli/AP-9 (EC50 = 15.70 ± 3.77 mg/mL). The PCA showed significant contributions of polyphenols and flavonoids towards biochemical assays, while CA revealed similarities and associations among various cultivars. Our study revealed that Habbi, Waflu Chuli, Thukdeena and Balaani kernels are rich sources of bioactive compounds and possess significant antioxidant and anticancer activity and can contribute considerably in the prevention and treatment of chronic health disorders.

Profiling of hydroxycinnamoylquinic acids in plant extracts using in-source CID fragmentation

Hydroxycinnamoylquinic acids (HCQAs) are a major class of phenolic plant secondary metabolites, belonging to the chlorogenic acid family. Various health-beneficial properties of HCQAs have been shown, which has drawn interest for HCQA profiling in plants of human consumption. However, this task remains challenging, because several isomeric HCQAs can be present in the sample with identical molecular formulae and the limited availability of reference standards poses additional challenges to their identification. In the present work, a high performance liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (HPLC-ESI-Q/TOF-MS) method accompanied with an effective data filtering protocol is presented, which is shown to be suitable for the identification of HCQAs in plant materials in a non-targeted manner. Both collision-induced dissociation (CID) fragmentation performed in a collision cell and in-source (CID) fragmentation were used to produce accurate mass fragments. It was shown that fragmentation characteristics required for identification of regio-isomers of HCQAs can be achieved with in-source CID fragmentation, enabling the use of a single-stage MS system with in-source fragmentation for convincing identification of HCQAs. Based on a thorough validation of identified HCQA compounds using coffee bean extracts as reference samples, comprehensive profiling of HCQAs in two apricot (Prunus armeniaca L.) genotypes ('Preventa' and 'Gönci magyarkajszi') was carried out for the first time and the following 10 HCQAs were shown to be present in apricot fruit: 3-caffeoylquinic acid (CQA), cis-3-CQA, 4-CQA, 5-CQA, cis-5-CQA, 3,5-diCQA, 3-p-coumaroylquinic acid (pCoQA), 4-pCoQA, 3-feruloylquinic acid (FQA) and cis-3-FQA. Copyright © 2016 John Wiley & Sons, Ltd.

HIGHLIGHTS

An HPLC-ESI-Q/TOF-MS method suitable for the identification of hydroxycinnamoyilquinic acids (HCQAs) in plant material in a non-targeted manner was developed. Single-stage, high-resolution MS system with in-source fragmentation was shown to be suitable for convincing identification of HCQAs. Comprehensive profiling of HCQAs in two apricot (Prunus armeniaca L.) genotypes was carried out for the first time. Copyright © 2016 John Wiley & Sons, Ltd.

Three week dietary intervention using apricots, pomegranate juice or/and fermented sour sobya and impact on biomarkers of antioxidative activity, oxidative stress and erythrocytic glutathione transferase activity among adults

BACKGROUND

The beneficial effects of the polyphenol (PP) rich fruits and Lactic acid bacteria fermented foods had been reported as cost-effective strategies for health promotion. Randomized controlled trial was designed to test the hypothesis that daily intake of polyphenol rich pomegranate juice (PGJ) or/ and lactic acid bacteria fermented sobya (FS) improved selected biomarkers of relevance to heath status.

METHODS

The design of the human trial consisted of 35 healthy adults, who were distributed to 5 equal groups; The first group served as control and received no supplements; the second group received fresh apricot fruits (200 g); the third (PGJ) (250 g), the fourth a mixture of PGJ (150 g) and FS (140 g) and the fifth group received (FS) (170 g). The supplements were served daily between 5 - 6 pm for 21 days. Blood and urine samples were collected at days zero and 22 of the dietary intervention. The supplements were analyzed chemically for (PP) contents and total antioxidative activities and microbiologically for selected bacteria and yeast counts. The blood samples were assayed for plasma antioxidative activities and for erythrocytic glutathione transferase activity (E-GST). Urine samples were analyzed for the excretions of total PP, antioxidative activity and thiobarbituric acid reactive substances (TBARS).

STATISTICAL ANALYSIS

Two way analysis of variance (ANOVA) was conducted and included the main effects of treatment, time and treatment x time interaction.

RESULTS

Daily intake of (PGJ) for 3 weeks significantly increased the plasma and urinary anti-oxidative activities and reduced the urinary excretion of (TBARS). Daily intake of (FS) for 3 weeks increased only (E-GST) activity. Daily intake of a mixture of PGJ and (FS) was also effective.

CONCLUSIONS

The daily intakes of PGJ and/ or (FS) affected positively selected biomarkers of relevance to health status. These functional foods have potential implication for use as bio-therapeutic foods.

TRIAL REGISTRATION

The study was approved by the research ethical committee of the Ministry of Health & population, Egypt. The trial registration - the unique identifying number. (REC) decision No 12-2013-9, which complied with the Declaration of Helsinki guidelines (2004). The protocol was fully explained to all subjects and written informed consent was obtained before their participation in the trial.

Phenolic compounds in Rosaceae fruit and nut crops

The demand for new fruit cultivars with high levels of phytochemicals, in particular phenolic compounds, has received increasing attention from biochemists, pharmaceutical companies, plant breeders, and the general public due to their health benefits. This review focuses on the economically important Rosaceae, which contains varying proportions and concentrations of these compounds. The paper discusses the common phenolics in the Rosaceae including phenolic acids, flavonols, flavanols, anthocyanins, and dihydrochalcones. The nonextractable phenolics are also presented but not discussed in detail. The metabolism and bioavailability of phenolics, as well as human and environmental factors that affect their concentration and composition, are highlighted. Furthermore, the paper presents different approaches for biofortification and posits that breeding may be the most viable and sustainable option as it improves other fruit quality traits simultaneously and increases confidence in adoption of new cultivars with enhanced consumer appeal.

Phenolic compounds and vitamins in wild and cultivated apricot (Prunus armeniaca L.) fruits grown in irrigated and dry farming conditions

Background

Turkey is the main apricot producer in the world and apricots have been produced under both dry and irrigated conditions in the country. In this study, phenolic compounds and vitamins in fruits of one wild (Zerdali) and three main apricot cultivars (‘Cataloglu’, ‘Hacihaliloglu’ and ‘Kabaasi’) grown in both dry and irrigated conditions in Malatya provinces in Turkey were investigated.

Results

The findings indicated that higher content of phenolic compounds and vitamins was found in apricot fruits grown in irrigated conditions. Among the cultivars, ‘Cataloglu’ had the highest rutin contents both in irrigated and dry farming conditions as 2855 μg in irrigated and 6952 μg per 100 g dried weight base in dry conditions and the highest chlorogenic acid content in irrigated and dry farming conditions were measured in fruits of ‘Hacıhaliloglu’ cultivar as 7542 μg and 15251 μg per 100 g dried weight base. Vitamin C contents in homogenates of fruit flesh and skin was found to be higher than β-caroten, retinol, vitamin E and lycopen contents in apricot fruits both in irrigated and dry farming conditions.

Conclusion

The results suggested that apricot fruits grown in both dry and irrigated conditions had high health benefits phytochemicals and phytochemical content varied among cultivars and irrigation conditions as well. However, more detailed biological and pharmacological studies are needed for the demonstration and clarification of health benefits of apricot fruits.

Characterization and the effect of maturity at harvest on the phenolic and carotenoid content of Northeast USA Apricot (Prunus armeniaca) varieties

The phenolic and carotenoid content and quality indices of five Northeast apricot varieties were assessed over two years and the impact of maturity at harvest was evaluated. Four varieties were analyzed at commercial and tree ripe stages and one variety after storage for 4 weeks (0-1 °C, 90-95% relative humidity). Total phenolic content ranged from 44.0 to 345.1 mg/100 g, total antioxidant capacity (oxygen radical absorbance capacity assay) from 2096.9 to 7165.1 μmol/100 g, and total carotenoid content from 1312.1 to 7371.1 μg/100, fresh weight. 'Hargrand' apricot had the highest phenolic and carotenoid content. Catechin, chlorogenic acid, and neochlorogenic acid were the predominant phenolic compounds and β-carotene was the predominant carotenoid compound. Carotenoid content increased with ripening and postharvest storage while changes in phenolic content and antioxidant capacity were variety-dependent. Results show the apricot varieties studied to be good or excellent sources of vitamin A despite moderate carotenoid content attributed to cultivation in a colder climate.

From genotype to apricot fruit quality: the antioxidant properties contribution

Apricot fruit (Prunus armeniaca L.) quality strictly relates to the eating quality of fresh produce. Since consumers are more and more interested in healthy food, and apricot germplasm shows a wide choice of new selections and cultivars, apricot nutraceutical properties are under evaluation in order to select outstanding genotypes, which may link breeding and marketing. In the present study, 18 apricot genotypes of the Italian and international germplasm were evaluated over three years according to pomological, total antioxidant and total phenols attributes using principal component and hierarchical cluster analyses. The antioxidant capacity ranged from 1.24 to 11.47 μmolTE gFW⁻¹ and total phenols from 0.22 to 1.58 mgGAE gFW⁻¹. Four outstanding genotypes stood out as healthy food for fresh consumption which may also be introduced in breeding programs to produce new cultivars with improved nutraceutical values in addition to fruit qualitative attributes.