Physico-chemical and textural quality attributes of pomegranate cultivars (Punica granatum L.) grown in the Sultanate of Oman

Qualitative and biochemical characteristics of pomegranate fruit grown using reclaimed water and low input fertigation treatments at harvest and during storage

In recent years, severe climate change leading to by water scarcity reduced water quality has increased the need for effective irrigation strategies for agricultural production. Among these, the reuse of reclaimed water represents a non-expensive and reliable solution. The effect of conventional or reclaimed water, applying convention or smart fertigation system, were investigated during two irrigation seasons on yield, qualitative and biochemical traits of pomegranates fruit (cv Wonderful One) at harvest, and after storage at 7 °C. The results of this study showed that using reclaimed waters with different fertigation systems did not affect the pH values, total soluble solids, and titratable acidity on pomegranates fruit showing slight decrease changes only during postharvest storage. On the other hand, the respiration rate was not affected by water quality. Furthermore, the antioxidant activity was also preserved during storage in pomegranates fruit from plants irrigated with reclaimed water by applying conventional or smart fertigation. The analysis also identified 52 compounds by UHPLC-MSn and HPLC-UV-Vis analyses. A slight decrease (about 17 %) at harvest and during storage in polyphenols content was shown in fruit grown using reclaimed water. The study demonstrates that using reclaimed water is a sustainable and effective way to limit the use of conventional water for irrigating pomegranate crops without significant reduction in yield, or in qualitative and nutritional values of the fruit at harvest and during storage.

Multifunctional Pomegranate Peel Microparticles with Health-Promoting Effects for the Sustainable Development of Novel Nutraceuticals and Pharmaceuticals

Recovering the bioactive components from pomegranate peel (PP) in the fruit-processing industry has attracted great attention in terms of minimizing the waste burden, as well as providing a new source of a multitude of functional compounds. The present study aimed to develop a feasible microencapsulation process of PP extract by using pectin and a pectin/2-hydroxypropyl-β-cyclodextrin (HP-β-CD) blend as coating materials. Microsized powders obtained by a spray drying technique were examined in terms of technological characteristics, exhibiting high powder yield and desirable moisture content, flowability, and cohesive properties. Assuming that the interactions with the used biopolymers occur on the surface hydrophobic domain, their presence significantly improved the thermal stability of the microencapsulated powders up to 200 °C. The health-promoting effects of PP have been associated with its high content in ellagitannins, particularly punicalagin. The obtained PP powders exhibited strong antioxidant and hypoglycemic potential, while an antimicrobial assay revealed their potent activity against Gram-positive bacteria. Additionally, an in vitro release study suggested that the used biopolymers can modify the release of target bioactive compounds, thus establishing a basis for developing an oral-controlled release system. Altogether, biowaste valorization from PP by the production of effective multifunctional microsized powders represents a sustainable way to obtain novel nutraceuticals and/or pharmaceuticals.

Pomegranate (Punica granatum L): A Fruitful Fountain of Remedial Potential

Pomegranate (Punica granatum L.) has long been used for medical purposes. Punica protopunicas and Punica granatum L. are two prominent species of pomegranate, generally known as "Anar" and farmed worldwide. Its medicinal value is documented in several ancient texts. This review article aims to provide a comprehensive overview of the remedial uses of pomegranate in traditional and modern medicine. The methodology employed for this review involves a systematic literature search, collection of relevant articles, and critical analysis of their content. The review covers the botanical properties, phytochemical composition, and diverse remedial applications of pomegranate, including its antioxidant, anti-inflammatory, anticancer, cardiovascular, antimicrobial, and dermatological properties. The gathered data emphasizes the potential benefits of pomegranate-derived compounds in managing a range of health issues. This review sheds light on the importance of pomegranate as a valuable natural resource for various therapeutic interventions and encourages further research to unlock its full remedial potential. Traditional medicine is gaining popularity to restore health to individuals with few negative effects. Due to the existence of key phytochemical elements such as flavonoids, punic acid, ellagic acid, anthocyanins, ellagitannins, flavones, and estrogenic flavonoids, it has a wide range of clinical applications.

First assessment of Iranian pomegranate germplasm using targeted metabolites and morphological traits to develop the core collection and modeling of the current and future spatial distribution under climate change conditions

Pomegranate has been considered a medicinal plant due to its rich nutrients and bioactive compounds. Since environmental conditions affect the amount and composition of metabolites, selecting suitable locations for cultivation would be vital to achieve optimal production. In this study, data on the diversity of targeted metabolites and morphological traits of 152 Iranian pomegranate genotypes were collected and combined in order to establish the first core collection. The multivariate analyses were conducted including principal component analysis (PCA), and cluster analysis. In addition, the current and future geographical distribution of pomegranate in Iran was predicted to identify suitable locations using the MaxEnt model. The results showed high diversity in the studied morphological and metabolic traits. The PCA results indicated that FFS, NFT, JA, and AA are the most important traits in discriminating the studied genotypes. A constructed core collection using maximization strategy consisted of 20 genotypes and accounted for 13.16% of the entire collection. Shannon-Weaver diversity index of a core collection was similar or greater than the entire collection. Evaluation of the core collection using four parameters of MD, VD, CR, and VR also indicated the maintenance of the genetic diversity of the original set. According to the MaxEnt model, altitude, average temperature of coldest quarter, and isothertmality were the key factors for the distribution of pomegranate. The most suitable areas for pomegranate cultivation were also determined which were located in arid and semi-arid regions of Iran. The geographic distribution of pomegranate in the future showed that the main provinces of pomegranate cultivation would be less affected by climatic conditions by the middle of the century. The results of this study provide valuable information for selection of elite genotypes to develop the breeding programs to obtain the cultivars with the highest levels of metabolic compounds for pharmaceutical purposes, as well as identification of the most suitable agro-ecological zones for orchard establishment.

Fungicidal activities and molecular docking of the marine alga Ulva lactuca and Punica granatum peel extracts on Alternaria tomato spot disease

In this study, we utilized pomegranate peel and marine algae Ulva lactuca (U. lactuca) as rich and sustained sources of bioactive compounds to combat tomato-black spot disease. n-Hexane extracts from the peel of pomegranate (Punica granatum) (PPE) and the marine algal biomass U. lactuca (ULE) were used alone and in combinations to verify their impact against Alternaria alternata (A. alternata). The applied extracts exhibited severe destructive effects on both fungal growth and structure such as mycelia malformation, underdeveloped conidia, cell wall deformation, and shrinkage. Moreover, increased deformations and protrusions, and notch-like structures, were noticed in A. alternata mycelia treated with mixed extracts (PPE and ULE) compared to all other treatments. The protein and reduced sugar contents in tomato fruits were significantly increased in the infected fruits with A. alternata. The highest enzyme activities of pectinase, cellulase, catalase (CAT), and ascorbate peroxidase (APX) were recorded in infected tomatoes in comparison with the healthy ones. Molecular docking studies showed that each extract is rich with bioactive compounds that have a promising inhibition effect on A. alternata cellulases. Pomegranate and Ulva extract showed promising antifungal activity against A. alternata which revealed their feasibility and applicability as biocontrol agents in postharvest disease management and food preservation against fungal pathogens.

Vis-NIR and SWIR hyperspectral imaging method to detect bruises in pomegranate fruit

Introduction

Fresh pomegranate fruit is susceptible to bruising, a common type of mechanical damage during harvest and at all stages of postharvest handling. Accurate and early detection of such damages in pomegranate fruit plays an important role in fruit grading. This study investigated the detection of bruises in fresh pomegranate fruit using hyperspectral imaging technique.

Methods

A total of 90 sample of pomegranate fruit were divided into three groups of 30 samples, each representing purposefully induced pre-scanning bruise by dropping samples from 100 cm and 60 cm height on a metal surface. The control has no pre-scanning bruise (no drop). Two hyperspectral imaging setups were examined: visible and near infrared (400 to 1000 nm) and short wavelength infrared (1000 to 2500 nm). Region of interest (ROI) averaged reflectance spectra was implemented to reduce the image data. For all hypercubes a principal components analysis (PCA) based background removal were done prior to segmenting the region of interest (ROI) using the Evince® multi-variate analysis software 2.4.0. Then the average spectrum of the ROI of each sample was computed and transferred to the MATLAB 2022a (The MathWorks, Inc., Mass., USA) for classification. A two-layer feed-forward artificial neural network (ANN) is used for classification.

Results and discussion

The accuracy of bruise severity classification ranged from 80 to 96.7%. When samples from both bruise severity (Bruise damage induced from a 100cm and 60 cm drop heights respectively) cases were merged, class recognition accuracy were 88.9% and 74.4% for the SWIR and Vis-NIR, respectively. This study implemented the method of selecting out informative bands and disregarding the redundant ones to decreases the data size and dimension. The study developed a more compact classification model by the data dimensionality reduction method. This study demonstrated the potential of using hyperspectral imaging technology in sensing and classification of bruise severity in pomegranate fruit. This work provides the foundation to build a compact and fast multispectral imaging-based device for practical farm and packhouse applications.

Comparative metabolomics reveal intraspecies variability in bioactive compounds of different cultivars of pomegranate fruit (Punica granatum L.) and their waste by-products

BACKGROUND

The different parts of pomegranate fruit are considered a powerful mixture of bioactive compounds yet the peels and pulps of the fruits are usually discarded and considered as industrial waste. In this work, ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QqQ-MS) was utilized for metabolomics analysis of different parts (peel, pulp, seed and juice) of pomegranate fruit cultivars to verify possible variations among the fruits and their waste products as potential sources of functional constituents.

RESULTS

Orthogonal projection to latent structure-discriminant analysis (OPLS-DA) coefficient-plot showed enrichment of phenolic compounds such as punicalagin and ellagic acid derivatives in pulp samples while seeds class was enriched in phlorizin, catechin and quercetin, juice class showed abundance of naringenin and pelargonidin-3-pentoside while peels were enriched in anthocyanins and flavonoids including cyanidin diglycoside, quercetin and luteolin glycosides. Although the juice samples of almost all tested cultivars showed remarkable cytotoxic activity, the pulp samples, particularly the Manfalouti cultivar, exhibited the most potent [half maximal inhibitory concentration (IC₅₀ ) = 2.367 ± 0.14 μg/mL in MCF-7, IC₅₀  = 3.854 ± 0.23 μg/mL in Hep-G2 cell lines]. OPLS models were constructed for determination of cytotoxicity-associated metabolites among where the coefficients plots revealed tannins; granatin A, ellagic acid derivatives, punicalagin α and β, in addition to anthocyanins and phenolic compounds; cyanidin diglycoside, quercetin, phlorizin, 3-O-caffeoylquinic acid, naringenin and liquiritin were more pertinent with cytotoxicity of the different parts of pomegranate fruit.

CONCLUSION

The results obtained allow for the full utilization of the resources of pomegranate fruit and its industrial waste as sources of bioactive compounds. © 2022 Society of Chemical Industry.

Comparative Evaluation of Yield and Fruit Physico-Chemical Characteristics of Five Commercial Cultivars of Pomegranate Grown in Southeastern Italy in Two Consecutive Years

This study, conducted over two consecutive seasons (2018–2019), evaluates the yield and fruit physico-chemical traits of five commercial cultivars (‘Mollar’, ‘Dente di Cavallo’, ‘Acco’, ‘Jolly red’ and ‘Wonderful’) grown in the orchard at Foggia (Puglia region, southeastern Italy). The results show significant variations among the investigated cultivars for many measured parameters; seasons also significantly affected some data. As an average of the years, both ‘Dente di Cavallo’ and ‘Wonderful’ significantly showed the highest numbers (16.8 and 15.2, respectively) and weights (9.3 Kg, respectively) of fruit per tree. ‘Jolly red’ had the highest percentage of edible portions (58.5%), the most intense red color in juice (a* value, 11.7), a light-red skin color (despite its name) (a*value, 31.1) and the smallest fruits (26.7% of diameter ≤ 80 mm). Total soluble solids of all cultivars were considerable above the minimum value (12 °Brix) required for commercial use. ‘Wonderful’ significantly presented the highest value of juice acidity (2.5 g citric acid 100 mL−1) and the lowest MI value, and therefore it was classified as sour. Both ‘Dente di Cavallo’ and ‘Wonderful’ had significantly higher phenolic contents (591.0 and 519.1 mg 100 mL−1, respectively) than the other cultivars, while ‘Dente di Cavallo’ significantly showed the highest antioxidant activity value (6.4 mmol TE 100 L−1). The Stepwise Discriminant Analysis procedure allowed a significant differentiation among the cultivars. Correlation analysis showed a considerable relation among the different fruit traits. The present data are helpful in the selection of elite desirable pomegranate cultivars to be used for commercial production.

Effect of Edible Coating on the Quality and Antioxidant Enzymatic Activity of Postharvest Sweet Cherry (Prunusavium L.) during Storage

The effects of edible chitosan coating (0.1%, 0.3%, 0.5% and 0.75% w/v) on the changes in the quality, respiration rate, total phenolic content and anthocyanin of postharvest sweet cherry (Prunus avium L.) at 10 °C were investigated. The activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were also determined. The result showed that the treatments of chitosan edible coating were effective at delaying the evolution of the parameters related to postharvest ripening, such as color and firmness, and respiration rate. The edible coatings also showed that the lower total phenolics and total antioxidant activity were maintained compared to that in the control associated with the overripening. It was suggested that the optimal quality and enhanced antioxidant enzymatic activities of postharvest cherry fruits were obtained by an edible coating of chitosan 0.5% up to 24 days at 10 °C. The chitosan edible coating could be favorable for extending shelf-life, maintaining the quality of sweet cherries.

Preliminary Studies on Suppression of Important Plant Pathogens by Using Pomegranate and Avocado Residual Peel and Seed Extracts

Potential synergistic action of aqueous extracts of pomegranate peel (PP), avocado peel (AP), and avocado seed (AS) wastes isolated by microwave-assisted extraction were assessed in in vitro and in vivo assays as biocontrol agents against several plant pathogenic fungi. The study findings contribute to the utilization of a value-added industrial byproduct and provide significant value in advancing the development of new plant protecting compositions that benefit from the synergistic effects between two important plant species that contain several natural bioactive compounds. More specifically, the in vitro results proved that the use of 100%-pure (PP) extracted waste affected the mycelium growth of Penicillium expansum. Furthermore, mycelium growth of Aspergillus niger was decreased by 10.21% compared to control after 7 days of growth in medium agar containing 100% AP and extracted waste. Moreover, mycelium growth of Botrytis cinerea was affected by equal volume of avocado extraction wastes (50% peel and 50% seed) only at the first 3 days of the inoculation, while at the seventh day of the inoculation there was no effect on the mycelium growth. Equal volumes of the examined wastes showed decreased mycelium growth of Fusarium oxysporum f.sp. lycopersici by 6%, while Rhizoctonia solani mycelium growth was found to be the most sensitive in PP application. In addition, the in vivo assay shown that PP extract suppresses damage of tomato plants caused by R. solani followed by extracted wastes from AP. Based on the research findings, it can be argued that PP and AP extracts can be used as natural antifungals instead of dangerous synthetic antifungals to effectively treat phytopathogens that cause fruit and vegetable losses during cultivation.

Effects of Gum Arabic Coatings Enriched with Lemongrass Essential Oil and Pomegranate Peel Extract on Quality Maintenance of Pomegranate Whole Fruit and Arils

The effects of gum arabic coatings combined with lemongrass oil and/or pomegranate peel extract on freshly harvested mature 'Wonderful' pomegranate fruit were studied. Fruit were coated with gum arabic (GA) (1.5% w/v) alone or enriched with lemongrass oil (LM) (0.1% v/v) and/or pomegranate peel extract (PP) (1% w/v). Fruit were packed into standard open top ventilated cartons (dimensions: 0.40 m long, 0.30 m wide and 0.12 m high), and stored for 6 weeks at 5 ± 1 °C (90% RH). Evaluations were made every 2 weeks of cold storage and after 5 d of shelf life (20 °C and 65% RH). Fruit coated with GA + PP (4.09%) and GA + PP + LM (4.21%) coatings recorded the least cumulative weight loss compared to the uncoated control (9.87%). After 6 weeks, uncoated control and GA + PP + LM recorded the highest (24.55 mg CO2Kg-1h-1) and lowest (10.76 mg CO2Kg-1h-1) respiration rate, respectively. Coating treatments reduced the incidence of decay and treatments GA + LM + PP and GA + PP recorded the highest total flavonoid content between 2 and 6 weeks of storage. The findings suggest that GA coatings with/without LM and PP can be a beneficial postharvest treatment for 'Wonderful' pomegranates to reduce weight loss and decay development during cold storage.

Identification of the superior genotypes of pomegranate (Punica granatum L.) using morphological and fruit characters

Pomegranate (Punica granatum L.) fruits can be used for fresh consumption, industrial processing, and medicinal purposes. Therefore, it is necessary to evaluate the diversity of its different genotypes to be aware of their potential. In the present study, morphological and pomological diversity of 70 native pomegranate genotypes was evaluated to introduce superior selections. Most of the characters showed significant differences among the genotypes. Fruit weight ranged from 103.28 to 407.59 g, and total aril weight per fruit ranged from 51.55 to 238.97 g. Fruit peel color was highly variable and included yellow, yellow-red, red, and red-brown. The sunburn and cracking disorders were not observed on the peel of the majority of genotypes. Aril color was highly variable, including light milky, pink, white-red, red, and red-black. Seed was soft in 17, semi-soft in 21, and hard in 32 genotypes. Total aril weight per fruit was positively and significantly correlated with fruit length (r = 0.64), fruit diameter (r = 0.87), fruit weight (r = 0.95), fruit stalk diameter (r = 0.52), fruit peel weight (r = 0.71), and aril shape (r = 0.32). Principal component analysis (PCA) showed that the fruit-related traits were important for determining differences between genotypes. Based on the ideal values of commercial characters of pomegranate, 15 genotypes were promising and thus could be directly cultivated in the orchards and used in the breeding programs.

Blanching Pre-Treatment Promotes High Yields, Bioactive Compounds, Antioxidants, Enzyme Inactivation and Antibacterial Activity of 'Wonderful' Pomegranate Peel Extracts at Three Different Harvest Maturities

'Wonderful' pomegranate (Punica granatum L.) peel contains a wide range of phytochemicals including vitamins, dietary fibre, phenolic compounds, and antioxidant properties. Yet, it is often used as animal feed or discarded in landfills, which is not the best eco-friendly way to utilize this phenolic-rich bioresource. Finding novel ways of utilizing pomegranate peel waste could prove a more profitable and eco-friendlier alternative that is far more beneficial to the economy. Adding a blanching pre-treatment step at optimal conditions prior to processing of pomegranate peel aids in the inactivation of quality changing enzymes such as polyphenol oxidase (PPO) and peroxidase (POD), which are accountable for the degradation reactions that cause breakdown of nutrients and phytochemicals. This study aimed to determine the effect of blanching at 80 °C for 3 min on the yield, polyphenol content, antioxidant properties, enzyme inactivation, and antibacterial activity of 'Wonderful' pomegranate peel ethanolic extracts from three different harvest maturities (unripe, ripe, and over ripe), including a comprehensive characterization and quantification using liquid chromatography-mass spectrometry (LC-MS). The blanched unripe peel extracts exhibited the highest total phenolic content, total tannin content, 2,2-diphenyl-1-picryl hydrazyl (DPPH) antioxidant activity, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activity and ferric ion reducing antioxidant power (FRAP) at 14.0 mg gallic acid equivalent (GAE)/g dry mass (DM), 1.0 mg GAE/g DM, 359.1 µmol Trolox/g DM, 912.2 µmol Trolox/g DM and 802.5 µmol Trolox/g DM, respectively. There was significant (p < 0.05) decrease in PPO and POD activity of all blanched pomegranate peel extracts. The blanched unripe peel extracts had the lowest PPO activity at 0.2 U/g fresh weight (FW), with a 70% PPO inactivation compared to ripe and over ripe harvest, whereas the highest POD inactivation was recorded at 67% in over ripe peel extracts. All blanched peel extracts, irrespective of harvest maturity, had minimum inhibitory concentration (MIC) values at 160 µg/mL against all four bacteria strains tested, which included two Gram-positive bacterial strains (Bacillus subtilis ATCC 6051 and Staphylococcus aureus ATCC 12600) and two Gram-negative bacteria (Escherichia coli 11775 and Klebsiella pneumonia ATCC 13883). A total of 25 metabolites including phenolic acids (4), organic acids (1), flavonoids (4), ellagitannins (13), and other polyphenols (3) in all three pomegranate peel samples were tentatively identified after LC-MS profiling. The blanched unripe peel extracts showed significantly higher punicalin α and β, β punicalagin, catechin, epicatechin content at 414 mg/g, and 678 mg/g, 151 mg/g, 229 mg/g, respectively, compared to peel extracts from other harvest maturities. This study provides supportive information for the commercial utilization of pomegranate fruit peel as source of value-added ingredients for the development of novel food, cosmetics, and pharmacological products.

Co-application of mineral and organic fertilizers under deficit irrigation improves the fruit quality of the Wonderful pomegranate

Background

The aim of this study was to determine the individual and interactive effects of various irrigation regimes and fertilizer treatments on the quality of the Wonderful pomegranate cultivar.

Methods

Two field experiments were conducted over two consecutive growing seasons (2018 and 2019) to determine the individual and interactive effects of various organic and mineral fertilizer treatments on the fruit quality of the Wonderful pomegranate under various irrigation conditions. A split-plot experimental design was used, in which the main plots included three levels of irrigation (100%, 80%, and 60% of evapotranspiration) while the subplots included five fertilizer treatments with different co-application ratios of mineral and organic fertilizers.

Results

All tested physicochemical properties of the fruit were significantly affected by the irrigation treatment, with irrigation at 80% of evapotranspiration representing the best strategy for reducing water use and improving fruit quality. Moreover, the co-application of mineral and organic fertilizers had a significant effect on fruit quality, with 75% mineral + 25% organic fertilizer improving all of the physical and chemical properties of the fruit in both experimental seasons. Irrigation and the co-application of mineral and organic fertilizers also had a significant interaction effect on the physicochemical attributes of fruit, which further increased fruit quality.

Conclusions

The co-application of organic and mineral fertilizers produced better quality pomegranate fruit than mineral fertilizer alone under deficit irrigation conditions. This technique could therefore be applied to improve the fruiting of horticultural trees in arid growing regions.

Postharvest Losses of Pomegranate Fruit at the Packhouse and Implications for Sustainability Indicators

Pomegranate fruit, like other types of fresh horticultural produce, are susceptible to high incidence preharvest and postharvest losses and waste. Several studies have been done to improve the production and handling of pomegranate fruit to meet market standards, but little has been done in loss quantification, especially in the early stage of the value chain such as the packhouse. Therefore, the aim of this study was to quantify the magnitude of pomegranate fruit losses at the packhouse, identify the causes, and estimate the impacts of losses. The study was conducted on a case study packhouse in the Western Cape Province of South Africa from February to March 2020. The direct measurement method, which involved physical identification of the causes of loss on individual fruit, was used for data collection. Loss quantification involved the calculation of lost fruit proportional to the amount put in the packhouse processing line. The results showed that losses ranged between 6.74% to 7.69%, which translated to an average of 328.79 tonnes of pomegranate fruit removed during packhouse operation per production season at the investigated packhouse. This magnitude of lost fruit was equivalent to over ZAR 29.5 million (USD 1,754,984) in revenue, in addition to the opportunity costs of resources used to produce lost fruit.

Telenomus nizwaensis (Hymenoptera: Scelionidae), an important egg parasitoid of the pomegranate butterfly Deudorix livia Klug (Lepidoptera: Lycaenidae) in Oman

The pomegranate butterfly Deudorix (= Virachola) livia is the major pest of pomegranate, a crop of economic importance, in Oman. A species of parasitoid wasp in the hymenopteran family Scelionidae is responsible for high levels of mortality of its eggs. This wasp is described herein as Telenomus nizwaensis Polaszek sp. n., based on morphology and DNA sequence data. T. nizwaensis is currently known only from D. livia, which is also a pest of economic importance on other crops in North Africa, the Arabian Peninsula, and the Mediterranean. We summarise current knowledge of T. nizwaensis life-history and its potential to provide biological pest control.

Green synthesis of silver nanoparticles using Omani pomegranate peel extract and two polyphenolic natural products: characterization and comparison of their antioxidant, antibacterial, and cytotoxic activities

Background

Green synthesis of silver nanoparticles (AgNPs) has gained popularity due to the economical and eco-friendly approach associated with it. The aim of the study was to biosynthesize silver nanoparticles using pomegranate peel extract (PPE), quercetin (Q), and gallic acid (GA) and to evaluate their antioxidant, antimicrobial, and cytotoxic activities.

Results

A sharp color change from yellow to brown, appearance of a peak in a UV spectrum around 413–425 nm, and four intense peaks in XRD spectra matching with the reference silver crystal confirmed the formation of AgNPs. SEM and TEM analysis revealed particles to be mostly spherical with few aggregates. Average particle size distribution and zeta potential was found to be 43.6 nm and −18.01mV, 31.6 nm and −21.5 mV, and 21.7 nm and −27.9 mV for Q-AgNPs, P-AgNPs, and GA-AgNPs, respectively. P-AgNPs showed excellent in vitro antioxidant activity (84.85–89.20%) and cytotoxic activity (100% mortality). P-AgNPs and GA-AgNPs exhibited good antimicrobial activity against the four bacterial strains comparable to the reference antibiotics but Q-AgNPs failed to inhibit the growth of P. vulgaris.

Conclusions

Omani pomegranate peel extract seems to be a potential and alternative source for the simple, one pot, eco-friendly green synthesis of extracellular stable AgNPs. The synthesized nanoparticles have the potential to be developed as possible antimicrobial agents and antioxidants.

Graphical abstract

Effect of Blanching on Enzyme Inactivation, Physicochemical Attributes and Antioxidant Capacity of Hot-Air Dried Pomegranate (Punica granatum L.) Arils (cv. Wonderful)

Blanch-assisted hot-air drying of pomegranate arils with blanching treatments 90 °C for 30 s, 100 °C for 60 s, and unblanched (control) arils were investigated. Effects of blanching on enzyme inactivation (polyphenol oxidase and peroxidse), colour, texture, and other qualities of dried arils were discussed. The hot-air drying conditions were 60 °C, 19.6% relative humidity, and 1.0 m s−1 air velocity. Results showed that blanching reduced enzyme activity by 76% and 68% for blanched arils treated at 90 °C for 30 s and 100 °C for 60 s, respectively, compared to unblanched arils. With regard to the total colour difference (TCD), unblanched arils were 20.9% and 16.6% higher than blanched arils treated at 90 °C for 30 s and 100 °C for 60 s, respectively. Furthermore, the total soluble solids (TSS) for unblanched aril increased significantly from 16.1 to 24.9 °Brix after drying, followed by arils treated at 90 °C for 30 s and 100 °C for 60 s (21.4; 18.5 °Brix), respectively. Among the blanching treatments, dried arils treated at 90 °C for 30 s had the highest total anthocyanin content (28.6 mg C3gE/g DM), followed by 100 °C for 60 s (24.8 mg C3gE/g DM). Similarly, dried arils treated at 90 °C for 30 s had the highest radical scavenging activity (RSA) (32.1 mM TE/g DM) while the least was observed with unblanched arils (17.0 mM TE/g DM). Overall, the blanching treatment was more effective to maintain the quality attributes of pomegranate dried arils.

Bioactive compounds and quality evaluation of 'Wonderful' pomegranate fruit and juice as affected by deficit irrigation

BACKGROUND

Persistent water shortage, typical of Mediterranean agricultural systems, has driven production methods towards the use of regulated deficit irrigation (DI) strategies, which may allow important water savings. To evaluate the extent to which pomegranate (cv. 'Wonderful') attributes may differ depending on the irrigation application rates, we investigated the effect of four different irrigation regimes (100, 75, 50, and 25% of maximum crop evapotranspiration - ET_C ) on their morpho-pomological, physico-chemical properties, and bioactive compounds.

RESULTS

The weight and the size of whole fruits, and the number of arils and their weight per fruit, decreased significantly with the restriction of ET_C water volumes applied to the crop. Minor differences were observed in soluble solids, pH, color of fruit skins, arils, and juices, although total acidity, maturity index, vitamin C, glucose, and fructose were not affected. However, total phenol content and antioxidant activity in juices were higher in the samples subjected to the DI treatments than in those submitted to full irrigation, showing the highest value at 50% ET_C . A similar trend was found for anthocyanins delphinidin-3,5-diglucoside and delphinidin-3-glucoside, reaching the highest concentration at 50% ET_C . Among non-anthocyanin compounds, punicalagins and pedunculagin were more concentrated in the 75% ETc samples.

CONCLUSION

The results of the present study indicate that the DI strategy throughout all the growing season is likely to have important implication for the pomegranate's physical, chemical, and phytochemical properties. Knowledge of them is useful in view of their processing and nutritional properties. © 2020 Society of Chemical Industry.

Processing Factors Affecting the Phytochemical and Nutritional Properties of Pomegranate (Punica granatum L.) Peel Waste: A Review

Pomegranate peel has substantial amounts of phenolic compounds, such as hydrolysable tannins (punicalin, punicalagin, ellagic acid, and gallic acid), flavonoids (anthocyanins and catechins), and nutrients, which are responsible for its biological activity. However, during processing, the level of peel compounds can be significantly altered depending on the peel processing technique used, for example, ranging from 38.6 to 50.3 mg/g for punicalagins. This review focuses on the influence of postharvest processing factors on the pharmacological, phytochemical, and nutritional properties of pomegranate (Punica granatum L.) peel. Various peel drying strategies (sun drying, microwave drying, vacuum drying, and oven drying) and different extraction protocols (solvent, super-critical fluid, ultrasound-assisted, microwave-assisted, and pressurized liquid extractions) that are used to recover phytochemical compounds of the pomegranate peel are described. A total phenolic content of 40.8 mg gallic acid equivalent (GAE)/g DM was recorded when sun drying was used, but the recovery of the total phenolic content was higher at 264.3 mg TAE/g when pressurised liquid extraction was performed. However, pressurised liquid extraction is costly due to the high initial investment costs and the limited possibility of carrying out selective extractions of organic compounds from complex peel samples. The effects of these methods on the phytochemical profiles of pomegranate peel extracts are also influenced by the cultivar and conditions used, making it difficult to determine best practice. For example, oven drying at 60 °C resulted in higher levels of punicalin of 888.04 mg CE/kg DM compared to those obtained 40 °C of 768.11 mg CE/kg DM for the Wonderful cultivar. Processes that are easy to set up, cost-effective, and do not compromise the quality and safety aspects of the peel are, thus, more desirable. From the literature survey, we identified a lack of studies testing pretreatment protocols that may result in a lower loss of the valuable biological compounds of pomegranate peels to allow for full exploitation of their health-promoting properties in potentially new value-added products.

Chemical and physical attributes of fruit juice and peel of pomegranate genotypes grown in Florida, USA

The global demand for pomegranate has led to increasing research and improvement of cultivars that produce higher antioxidant compounds. The current study was carried out to evaluate the bioactive constituents and physical properties of fourteen pomegranate genotypes grown in the subtropical region of Florida. There were differences in aril color among genotypes. The highest total anthocyanin content was found in 'Ariana', 'Molla Nepes', and 'Parfianka' genotypes. Furthermore, total anthocyanin content in peel ranged from 2.14 to 10.86 mg/100 g dry weight. Total phenolic content in the pomegranate fruit juice differed significantly among genotypes, varying from 365.71 to 1167.40 mg/L. Moreover, total phenolic content in the fruit peel ranged from 1313.08 to 1700.07 mg/L. Total phenolic compounds and reducing power activity in peel tissues were greater than in pomegranate juice. Reducing power activity and titratable acidity were positively and significantly correlated with total anthocyanin content.

Pomegranate Mesocarp against Colitis-Induced Visceral Pain in Rats: Effects of a Decoction and Its Fractions

The management of chronic visceral pain related to Inflammatory Bowel Diseases or Irritable Bowel Syndrome is still a clinical problem and new therapeutic strategies continue to be investigated. In the present study, the efficacy of a pomegranate decoction and of its polysaccharide and ellagitannin components in preventing the development of colitis-induced abdominal pain in rats was evaluated. After colitis induction by 2,4-dinitrobenzenesulfonic acid (DNBS), the pomegranate decoction (300 mg kg-1), polysaccharides (300 mg kg-1), and ellagitannins (45 mg kg-1) were orally administered for 14 days. Repeated treatment with decoction reduced visceral hypersensitivity in the colitic animals both at 7 and 14 days. Similar efficacy was shown by polysaccharides, but with lower potency. Ellagitannins administered at dose equivalent to decoction content showed higher efficacy in reducing the development of visceral pain. Macroscopic and microscopic evaluations performed on the colon 14 days after the damage showed that all three preparations reduced the overall amount of mast cells, the number of degranulated mast cells, and the density of collagen fibers in the mucosal stroma. Although ellagitannins seem to be responsible for most of the beneficial effects of pomegranate on DNBS-induced colitis, the polysaccharides support and enhance its effect. Therefore, pomegranate mesocarp preparations could represent a complementary approach to conventional therapies for promoting abdominal pain relief.

Transcriptomic changes associated with husk scald incidence on pomegranate fruit peel during cold storage

Pomegranate fruit is valued for its social, economic, aesthetic and health benefits. The fruit rapidly loses quality after harvest due to continued metabolic responses and physiological disorders under sub-optimal conditions. The incidence of physiological disorder such as husk scald manifests during storage and commercial shipping, which affects the appearance and limits marketability. Despite the importance of pomegranate husk scald, little information is available about the origin and molecular mechanisms. Therefore, the aim of this study was to investigate the scald incidence of pomegranate fruit at molecular level using RNA-Seq (Ion Proton™ Next Generation Sequencing) by analyzing peel transcriptomic changes. The RNA-seq analysis generated 98,441,278 raw reads. 652 Differentially Expressed Genes (DEGs) with a fold change of > |2|, a p value ≤ 0.05 and a false discovery rate (FDR) of <0.05 were identified between healthy and scald fruit peels. An analysis of the gene ontologies of these DEGs revealed the 432 genes were assigned with molecular functions, 272 as cellular components and 205 as part of biological processes. In this analysis, genes (Pgr023188 and Pgr025081) that encode uncharacterized protein and gene (Pgr007593) that encodes glycosyltransferase showed significantly highest fold changes. Genes (Pgr003448, Pgr006024 and Pgr023696) involved in various iron binding and oxidoreductase activities were significantly suppressed. This is the first transcriptome analysis of pomegranate fruit peel related to husk scald development. Results obtained from this study will add valuable information on husk scald related changes on pomegranate fruit at genomic level and provide insight on other related physiological disorders.

Pomegranate as a source of bioactive constituents: a review on their characterization, properties and applications

Increasing awareness about the use of compounds obtained from natural sources exerting health-beneficial properties, including antimicrobial and antioxidant effects, led to increased number of research papers focusing on the study of functional properties of target compounds to be used as functional foods or in preventive medicine. Pomegranate has shown positive health properties due to the presence of bioactive constituents such as polyphenols, tannins, and anthocyanins. Punicalagin is the major antioxidant, abundantly found in pomegranate's peel. Research has shown that pomegranate polyphenols not only have a strong antioxidant capacity but they also inhibit the growth of pathogenic bacteria like V. cholera, P. aeruginosa and S. aureus, B. cereus, E. coli, and S. virulence factor, and inhibits fungi such as A. Ochraceus, and P. citrinum. Compounds of natural origin inhibit the growth of various pathogens by extending the shelf life of foodstuffs and assuring their safety. Therefore, the need to find compounds to be used in combination with antibiotics or as new antimicrobial sources, such as plant extracts. On the basis of the above discussion, this review focuses on the health benefits of pomegranate, by summarizing the current body of research focusing on pomegranate bioactive constituents and their therapeutic potential against some pathogenic microbes.

Pattern recognition-based Raman spectroscopy for non-destructive detection of pomegranates during maturity

In this study, the feasibility of utilizing Fourier transform Raman spectroscopy, combined with supervised and unsupervised pattern recognition methods was considered, to distinguish the maturity stage of pomegranate "Ashraf variety" during four distinct maturity stages between 88 and 143 days after full bloom. Principal component analysis (PCA) as an unsupervised pattern recognition method was performed to verify the possibility of clustering of the pomegranate samples into four groups. Two supervised pattern recognition techniques namely, partial least squares Discriminant Analysis (PLS-DA) and Soft Independent Modeling of Class Analogy (SIMCA) were also used as powerful supervised pattern recognition methods to classify the samples. The results showed that in all groups of samples, the Raman spectra of the samples were correctly clustered using PCA. The accuracy of the SIMCA classification for differentiation of four pomegranate groups was 82%. Also, the overall discriminant power of PLS-DA classes was about 96%, and 95% for calibration and validation sample sets, respectively. Due to the misclassification among different classes of immature pomegranates, that was lower than the expected, it was not possible to discriminate all the immature samples in individual classes. However, when considering only the two main categories of "immature" and "mature", a reasonable separation between the classes were obtained using supervised pattern recognition methods of SIMCA and PLS-DA. The SIMCA based on PCA modeling could correctly categorize the samples in two classes of immature and mature with classification accuracy of 100%.

Effect of Ultrasonic Assisted Extraction on the Properties of Freeze-Dried Pomegranate Arils

Background:

All parts of the pomegranate (fruits, leaves, flowers, and roots) are traditionally used as a folk medicine due to its high antioxidant and phenolic property. The pomegranate fruit is known for its antimicrobial, anticancer and anti-arteriosclerotic properties.

Objective:

The current study aims to the effect of ultra-sonication and temperature (45°C) on freezedried pomegranate arils powder for extraction of phenolic and flavonoid compounds and to study the antioxidant activity.

Methods:

The freeze-dried arils of pomegranate (Ganesh variety) were procured and subjected to ultra- sonication methods at 45ºC applied for 30 minutes by using methanol, ethanol, water, acetone and hexane solvent for obtaining the extract. The methanolic extract showed the highest phenolic (3036.725 ± 5.39 Gallic acid equivalents mg/100gm), flavonoid (15882.088 ± 0.64, quercetin mg/100g), antioxidant activity (96.1367±0.13%) and free reducing antioxidant power (FRAP assay-18.9033 ± 0.12, Tor. mg/100 ml) respectively, as compared to the extract obtained through other solvents.

Results:

The results obtained indicate that the freeze-drying method and ultrasonic extraction method is one of the effective and quick methods for quality extraction of phenolic and flavonoids compounds from fruits.

Conclusion:

The technology can further be explored for the development of nutraceutical and health supplements.

Effects of Olive and Pomegranate By-Products on Human Microbiota: A Study Using the SHIME® in Vitro Simulator

Two by-products containing phenols and polysaccharides, a “pâté” (OP) from the extra virgin olive oil milling process and a decoction of pomegranate mesocarp (PM), were investigated for their effects on human microbiota using the SHIME^® system. The ability of these products to modulate the microbial community was studied simulating a daily intake for nine days. Microbial functionality, investigated in terms of short chain fatty acids (SCFA) and NH₄⁺, was stable during the treatment. A significant increase in Lactobacillaceae and Bifidobacteriaceae at nine days was induced by OP mainly in the proximal tract. Polyphenol metabolism indicated the formation of tyrosol from OP mainly in the distal tract, while urolithins C and A were produced from PM, identifying the human donor as a metabotype A. The results confirm the SHIME^® system as a suitable in vitro tool to preliminarily investigate interactions between complex botanicals and human microbiota before undertaking more challenging human studies.

Reactions of polyphenols in pomegranate peel with nitrite under simulated stomach conditions

Punicalagin and ellagic acid are the major polyphenols present in pomegranate peels. The contents of α-punicalagin, β-punicalagin, and ellagic acid in the pomegranate peels were approximately 75, 72, and 20 µM, respectively. The reactions of polyphenols in pomegranate peels with sodium nitrite under simulated stomach conditions were studied. The reactions decreased the polyphenolic contents of the pomegranate peels and accompanied the formation of nitroso compounds. The oxidation rates followed the order ellagic acid ＜α-punicalagin ≈ β-punicalagin. The results suggested that the reactions can occur in the stomach after a meal, while the pH changes from 2 to 4.5.

Instrumental measurement of pomegranate texture during four maturity stages

Texture of pomegranate fruit and arils are the main quality attributes in the food process industries. In this study, the texture properties of pomegranate fruit and arils (cv. "Ashraf") at four different stage of maturity (88, 109, 124, and 143 days after full bloom) were evaluated using the puncture test (rupture force and rupture energy) and compression test (bioyield force, rupture energy, and young modulus). The tests showed that all studied textural parameters were sensitive textural parameters for distinguishing the maturity stages. Rupture force and rupture energy of pomegranate fruit were determined at top, middle, and bottom positions of the fruit. The results showed that compression load values of aril increased with advances in maturity stage of fruit, while puncture load values of fruit decreased. The textural properties of pomegranate fruit and arils exhibited a strong dependence (p < .05) on the degree of maturity at harvesting time. Also results showed that rupture force of three different studied positions of fruit was severely different. The highest and lowest values were observed at top and middle position, respectively.

Optimization of Ultrasonic-Assisted Aqueous Two-Phase Extraction of Phloridzin from Malus Micromalus Makino with Ethanol/Ammonia Sulfate System

Application of an aqueous two-phase system (ATPS) coupled with ultrasonic technology for the extraction of phloridzin from Malus micromalus Makino was evaluated and optimized by response surface methodology (RSM). The ethanol/ammonium sulfate ATPS was selected for detailed investigation, including the phase diagram, effect of phase composition and extract conditions on the partition of phloridzin, and the recycling of ammonium sulfate. In addition, the evaluation of extraction efficiency and the identification of phloridzin were investigated. The optimal partition coefficient (6.55) and recovery (92.86%) of phloridzin were obtained in a system composed of 35% ethanol (w/w) and 16% (NH₄ )₂ SO₄ (w/w), 51:1 liquid-to-solid ratio, and extraction temperature of 36 °C. Comparing with the traditional solvent extraction with respective 35% and 80% ethanol, ultrasonic-assisted aqueous two-phase extraction (UAATPE) strategy had significant advantages with lower ethanol consumption, less impurity of sugar and protein, and higher extracting efficiency of phloridzin. Our result indicated that UAATPE was a valuable method for the extraction and preliminary purification of phloridzin from the fruit of Malus micromalus Makino, which has great potential in the deep processing of Malus micromalus Makino industry to increase these fruits' additional value and drive the local economic development.

Evaluation of unexplored pomegranate cultivars for physicochemical characteristics and antioxidant activity

The aim of present study was to evaluate the different pomegranate cultivars for physicochemical properties and to identify the best cultivars suitable for food processing and future breeding. Various attributes of fruit (including length, weight and diameter), rind (thickness and weight), calyx (length), aril (weight, percentage, length and width), seed (length and width) and juice (titratable acidity and soluble solids or TSS) were evaluated. Total and reducing sugar, pH, ascorbic acid, total phenolic contents, antioxidant activity and maturity index were also evaluated. A significant difference in all tested parameters was noted amongst the tested cultivars except calyx length, rind thickness, arils and seed dimensions. The antioxidant activity and total phenolic contents of pomegranate cultivars were ranged from 15.77 to 42% and 1158.9 to 1540.7 mg GAE L^-1. The cultivars Tor-390 and Sorkhak-859 were sweet in taste, while the rest of the cultivars have sweet sour taste. The study concluded that the majority of cultivars were rich source of total phenolics, ascorbic acid, total soluble solid and total sugars, which are beneficial to health. Some of the elite cultivars (NKP-561, SRK-296, SZR-385, SRK-878) showed high quality attributes and were suitable for future breeding programs.

Effect of substituted gelling agents from pomegranate peel on colour, textural and sensory properties of pomegranate jam

A series of pomegranate jams were prepared from a Tunisian ecotype (Tounsi) with different amounts of sugar (10, 20 and 30%) and low-methoxylated pectin (0.2, 0.7 and 1.2%). The most appreciated formulation was that contaning 30% sugars and 0.2% pectin. Then, commercial pectin was substituted by other gelling agents (pomegranate peel powders dried at 50°C vs lyophilized, pectin and fibre extracted from pomegranate peel) for the preparation of pomegranate peel-based jams. The elaborated jams were evaluated for physichochemical, colour, texture and sensory characteristics. Results revealed that the jam (JPP2) elaborated with 0.2% pectin extracted from pomegranate peel exhibited similar overall acceptability to that prepared with commercial pectin. However, it was more acceptable than other pomegranate peel-based jams, which was related to a better appreciation of sweetness and colour. According to the colour and texture measurements, this sample (JPP2) was more reddish and less firm than other samples.

Antioxidant properties and phenolic profile characterization by LC-MS/MS of selected Tunisian pomegranate peels

Antioxidant contents and activities of different extracts from four Tunisian pomegranate peels, locally called "Acide", "Gabsi", "Nebli" and "Tounsi", were studied. Peels samples were extracted with three solvents (water, ethanol and acetone). For each extract, the total phenol contents and antioxidant activity were evaluated. The highest values of polyphenol, tannins, flavonoids and anthocyanins were recorded in the acetone extract of Acide ecotype with 304.6 mg gallic acid equivalent/g; 292.23 mg gallic acid equivalent/g; 15.46 mg Quercetin/g and 54.51 mg cy-3-glu/100 g, respectively. The acetone extract of Acide ecotype also showed the highest free radical-scavenging and reducing power activity compared to other extracts. Besides, the phytochemical analysis by LC-MS/MS revealed a high content of ellagitannins with punicalagin and punicalagin derivatives as the major compounds that might be responsible for promising antioxidant activity of pomegranate peel extracts. Two compounds (Castalagin derivative and Galloyl-bis-HHDP-hex derivative) were detected only in "Acide" ecotype in important contents.

Genetic diversity of pomegranate germplasm collection from Spain determined by fruit, seed, leaf and flower characteristics

Background. Miguel Hernandez University (Spain) created a germplasm bank of the varieties of pomegranate from different Southeastern Spain localities in order to preserve the crop’s wide genetic diversity. Once this collection was established, the next step was to characterize the phenotype of these varieties to determine the phenotypic variability that existed among all the different pomegranate genotypes, and to understand the degree of polymorphism of the morphometric characteristics among varieties.

Methods. Fifty-three pomegranate (Punica granatum L.) accessions were studied in order to determine their degree of polymorphism and to detect similarities in their genotypes. Thirty-one morphometric characteristics were measured in fruits, arils, seeds, leaves and flowers, as well as juice characteristics including content, pH, titratable acidity, total soluble solids and maturity index. ANOVA, principal component analysis, and cluster analysis showed that there was a considerable phenotypic diversity (and presumably genetic).

Results. The cluster analysis produced a dendrogram with four main clusters. The dissimilarity level ranged from 1 to 25, indicating that there were varieties that were either very similar or very different from each other, with varieties from the same geographical areas being more closely related. Within each varietal group, different degrees of similarity were found, although there were no accessions that were identical. These results highlight the crop’s great genetic diversity, which can be explained not only by their different geographical origins, but also to the fact that these are native plants that have not come from genetic improvement programs. The geographic origin could be, in the cases where no exchanges of plant material took place, a key criterion for cultivar clustering.

Conclusions. As a result of the present study, we can conclude that among all the parameters analyzed, those related to fruit and seed size as well as the juice’s acidity and pH had the highest power of discrimination, and were, therefore, the most useful for genetic characterization of this pomegranate germplasm banks. This is opposed to leaf and flower characteristics, which had a low power of discrimination. This germplasm bank, more specifically, was characterized by its considerable phenotypic (and presumably genetic) diversity among pomegranate accessions, with a greater proximity existing among the varieties from the same geographical area, suggesting that over time, there had not been an exchange of plant material among the different cultivation areas. In summary, knowledge on the extent of the genetic diversity of the collection is essential for germplasm management. In this study, these data may help in developing strategies for pomegranate germplasm management and may allow for more efficient use of this germplasm in future breeding programs for this species.

Effects of different maturity stages and growing locations on changes in chemical, biochemical and aroma volatile composition of 'Wonderful' pomegranate juice

BACKGROUND

This study investigated the changes in chemical attributes of pomegranate fruit such as total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, pH, individual compounds (organic acids and sugars) and volatile composition as affected by fruit maturity status and growing location (Kakamas, Koedoeshoek and Worcester in South Africa). Headspace solid phase microextraction coupled with gas chromatography/mass spectrometry was used for volatile analysis.

RESULTS

A significant increase in TSS from 14.7 ± 0.6 to 17.5 ± 0.6 °Brix was observed with advancement in fruit maturity, while TA decreased from 2.1 ± 0.7 to 1.1 ± 0.3 g citric acid per 100 mL across all agro-climatic locations investigated. Fruit TSS/TA ratio and pH increased from 7.8 ± 2.6 to 16.6 ± 2.8 and from 3.3 ± 0.1 to 3.6 ± 0.2 respectively during fruit maturation across all agro-climatic locations. Fructose and glucose concentrations increased continually with fruit maturity from 69.4 ± 4.9 to 91.1 ± 4.9 g kg(-1) and from 57.1 ± 4.7 to 84.3 ± 5.2 g kg(-1) respectively. A total of 13 volatile compounds were detected and identified, belonging to five chemical classes. The most abundant volatile in unripe and mid-ripe fruit was 1-hexanol, while 3-hexen-1-ol was highest at commercial maturity.

CONCLUSION

Knowledge on the impact of fruit maturity and agro-climatic locations (with different altitudes) on biochemical and aroma volatile attributes of pomegranate fruit provides a useful guide for selecting farm location towards improving fruit quality and the maturity stage best for juice processing.