Influence of deficit irrigation and crop load on the yield and fruit quality in Wonderful and Mollar de Elche pomegranates

Comparative Chemical Analysis of Eight Punica granatum L. Peel Cultivars and Their Antioxidant and Anti-Inflammatory Activities

A comparative quali-quantitative study of the peel extracts of eight Punica granatum cultivars obtained from underexploited areas of South Italy was carried out in order to valorize them as health-promoting by-products. The results showed that all of the samples possessed 45 ellagitannins, consisting mainly of polyhydroxyphenoyls; 10 flavonoids, belonging to flavonol, flavone, and catechin classes; and 2 anthocyanins. The most representative compounds underwent quantification through a LC-MS/MS multiple reaction monitoring (MRM)-based method; their qualitative profile was almost superimposable, while variability in the quantitative phenolic content was observed. The antioxidant activity was investigated using cell-free and cell-based assays. The in vitro anti-inflammatory potential was also studied by monitoring three typical markers of inflammation (IL-1β, IL-6, and TNF-α). Moderate differences in both activities were observed between the cultivars. Results showed that all of the investigated peels have a potential use as healthy bioactive phytocomplexes due to the interesting antioxidant and anti-inflammatory activities; in particular from the bioinformatic approaches a series of compounds, including galloyl-, pedunculagin- and ellagic acid-based, were found to be highly correlated with bioactivity of the extracts. Finally, the bioactivities showed by a Campanian local cultivar, 'Granato di Aiello del Sabato', could promote its cultivation by local farmers and germplasm conservation.

Optimization of Extraction Conditions and Characterization of Volatile Organic Compounds of Eugenia klotzschiana O. Berg Fruit Pulp

Eugenia klotzschiana O. Berg is a native species to the Cerrado biome with significant nutritional value. However, its volatile organic compounds (VOCs) chemical profile is not reported in the scientific literature. VOCs are low molecular weight chemical compounds capable of conferring aroma to fruit, constituting quality markers, and participating in the maintenance and preservation of fruit species. This work studied and determined the best conditions for extraction and analysis of VOCs from the pulp of Eugenia klotzschiana O. Berg fruit and identified and characterized its aroma. Headspace solid-phase microextraction (HS-SPME) was employed using different fiber sorbents: DVB/CAR/PDMS, PDMS/DVB, and PA. Gas chromatography and mass spectrometry (GC-MS) were employed to separate, detect, and identify VOCs. Variables of time and temperature of extraction and sample weight distinctly influenced the extraction of volatiles for each fiber. PDMS/DVB was the most efficient, followed by PA and CAR/PDMS/DVB. Thirty-eight compounds that comprise the aroma were identified among sesquiterpenes (56.4%) and monoterpenes (30.8%), such as α-fenchene, guaiol, globulol, α-muurolene, γ-himachalene, α-pinene, γ-elemene, and patchoulene.

Melatonin Treatment to Pomegranate Trees Enhances Fruit Bioactive Compounds and Quality Traits at Harvest and during Postharvest Storage

The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with antioxidant activity at harvest and during storage at 10 °C for 60 days was assayed in two consecutive years, 2019 and 2020. In the first year, trees were treated with 0.1, 0.3 and 0.5 mM of melatonin along the developmental fruit growth cycle, and results showed that bioactive compounds (total phenolics and total and individual anthocyanins) and antioxidant activity at harvest were higher in fruits from melatonin-treated trees than in controls. Other fruit quality parameters, such as firmness, total soluble solids and aril red colour, were also increased as a consequence of melatonin treatment. In fruit from control tress, firmness and acidity levels decreased during storage, while increases occurred on total soluble solids, leading to fruit quality reductions. These changes were delayed, and even maintenance of total acidity was observed, in fruit from melatonin-treated trees with respect to controls, resulting in a fruit shelf-life increase. Moreover, concentration of phenolics and anthocyanins and antioxidant activity were maintained at higher levels in treated than in control fruits during the whole storage period. In general, all the mentioned effects were found at the highest level with the 0.1 mM melatonin dose, and then it was selected for repeating the experiment in the second year and results of the first year were confirmed. Thus, 0.1 mM melatonin treatment could be a useful tool to enhance aril content on bioactive compounds with antioxidant activity and health beneficial effects and to improve quality traits of pomegranate fruit, at harvest and during postharvest storage.

Inhibition of enzymes associated with metabolic and neurological disorder by dried pomegranate sheets as a function of pomegranate cultivar and fruit puree

BACKGROUND

Obesity and type 2 diabetes mellitus are the most extended current chronic diseases and also Alzheimer pathology which is a progressive degenerative neurological disorder. Therefore, finding effective enzyme inhibitors responsible for the development of these diseases are essential. Therefore, the aim of this study was to investigate the impact of fruit purée (Cydonia oblonga, Ziziphus jujube and Malus domestica) and pomegranate juice cultivar ('Mollar de Elche' and 'Wonderful') of dried pomegranate sheets (DS) on the inhibition of enzymes associated with metabolic (α-amylase, α-glucosidase, and pancreatic lipase activity), and neurological disorder (acetylcholinesterase and butyrylcholinesterase activity). Quality properties (colour coordinates, texture properties and sensory characteristics) of DS were also studied. In addition, it was researched the effect of storage conditions (4 months at 4 and 20 °C) on phenolic content.

RESULTS

DS from jujube had the highest antioxidant capacity and were characterized by the highest storage stability with respect to phenolic compounds. The α-amylase and α-glucosidase half maximal inhibitory concentration (IC₅₀ , in mg mL^-1 ) inhibition of DS ranged from 107 to 216 and from 55.2 to values indicating no effect, respectively. The inhibition toward pancreatic lipase (IC₅₀  < 5 mg mL^-1 ), acetylcholinesterase (ranged 9.15-22.2%) and butyrylcholinesterase (ranged 20.6-48.6%) was increased with the presence of total flavonoids and hydroxycinnamic acids content (identifying mainly in DS from quinces). It is noteworthy that none of the samples presented off-flavour notes, supporting the high quality of the products.

CONCLUSION

DS can be an innovative supplement to a diet as a snack used in the prevention of neurological changes and disorders of carbohydrate and lipid metabolism. © 2020 Society of Chemical Industry.

Volatile Composition and Sensory Attributes of Smoothies Based on Pomegranate Juice and Mediterranean Fruit Purées (Fig, Jujube and Quince)

To increase the intake of fruits and vegetables—especially among young people—the food industry is trying to develop new, easy-to-eat and long-shelf-life products, such as smoothies. Nowadays, consumers are choosing their foods based not only on nutritional/functional properties (content of polyphenols, vitamins, minerals, among others), but also on sensory attributes. The aim of this study was to investigate the volatile composition by HS-SPME and the sensory profile by descriptive sensory analysis of novel smoothies prepared by blending fig, jujube or quince purée with pomegranate juices (cv. Mollar de Elche or Wonderful) at two ratios purée:juice (40:60 or 60:40). Twenty-three volatile compounds were identified by GC-MS and classified as alcohols, aldehydes, esters, furans, ketones, terpenes and terpenoids. Among volatile compounds, the five predominant ones in the studied smoothies were: (i) 5-HMF (30.6%); (ii) 3-hexen-1-ol (9.87%); (iii) hexanal (9.43%); (iv) 1-hexanol (8.54%); and (v) 3-octanone (7.67%). Fig smoothies were sweet and had flavor and volatiles related to fig, pomegranate, and grape. While jujube products were bitter and had jujube and pear notes. Finally, quince smoothies were consistent, sour and had quince, apple and floral notes. Thus, the type of fruit purée used clearly determined the flavor of the final product. The smoothies prepared with Mollar de Elche pomegranate juice were characterized by having high intensity of pear odor/aroma and consistency, and the Wonderful smoothies were characterized by lower consistency and more intense pomegranate aroma and sourness.

Quality Parameters and Consumer Acceptance of Jelly Candies Based on Pomegranate Juice "Mollar de Elche"

There is an upward trend towards reducing or suppressing additives in foods, as well as reducing the use of E-numbers in labels providing clean label foods. Therefore, the development of confectionary products based exclusively on natural ingredients with antioxidant properties may offer valuable solutions to the confectionery industry. Fruit juices and purées may provide functional and organoleptic properties in jelly candies in a natural way. The consumption of pomegranate fruit and derivative products has increased due to their association with health benefits. The aim of this study was to determine consumer insights about pomegranate-based jellies, cultivar “Mollar de Elche”, as affected by formulation (100% pomegranate juice or 50%–50% pomegranate juice–apple purée) and type of sweetener (sugar or honey), and to link affective and descriptive data from sensory studies. The most valued quality parameter of pomegranate products, red color (measured by the green–red coordinate, a*), was not negatively affected by jelly preparation. It was determined that the main liking drivers for pomegranate jellies were intense red color and high brightness. The results might be used by pomegranate processing companies to improve their manufacturing protocols and to develop successful products meeting consumer demands and needs. The formulation containing 20% gelatin, pure “Mollar de Elche” pomegranate juice, 1% citric acid, and sucrose as sweetener provided the best quality of jellies in terms of color, texture, antioxidant capacity, and sensory attributes.

The Effects of Salicylic Acid and Its Derivatives on Increasing Pomegranate Fruit Quality and Bioactive Compounds at Harvest and During Storage

In the present research two experiments were performed to evaluate the effect of pre-harvest salicylic acid (SA), acetyl salicylic acid (ASA), and methyl salicylate (MeSa), applied as a foliar spray to pomegranate "Mollar de Elche," on crop yield, fruit quality parameters, and bioactive compounds at harvest and during storage. In the 2017 experiment, trees were treated with SA, ASA, and MeSa at 1, 5, and 10 mM and a higher crop yield (kg tree^-1 and number of harvested fruit tree^-1) and quality parameters (firmness, aril color, and individual sugars and organic acids) at harvest were obtained, as well as a higher concentration of phenolics, anthocyanins, and ascorbic acid. The best results were achieved with 10 mM dose of the three assayed compounds, which was chosen for the 2018 experiment, and results for crop yield and fruit quality attributes were confirmed. These quality traits and the concentration of phenolics, anthocyanins, and ascorbic acid were maintained at higher levels in pomegranate fruit from treated trees than in controls during prolonged storage at 10°C. In addition, the effects of salicylate treatments on increasing total and individual anthocyanin concentration in pomegranate arils led to arils with a deeper red color (Graphical Abstract) and, in turn, fruit that would be more appreciated in the international market. This fact, together with the increased crop yield, would contribute to the increased profit of this crop. Thus, pre-harvest treatment with salicylates, and especially SA at 10 mM concentration, could be a safe, natural, and new tool to improve fruit quality and its content on antioxidant compounds with health beneficial effects (namely, ascorbic acid, phenolics, and anthocyanins) at harvest and during storage.

Nutrition Quality Parameters of Almonds as Affected by Deficit Irrigation Strategies

The influence of full irrigation, double-regulated (RDI) and sustained deficit irrigation (SDI) treatments on almond quality was assessed by analyzing different parameters: sugars, organic acids, antioxidant activity, total phenolic content (TPC), and volatile compounds. Almond quality studies for plants submitted to water stress are scarce, and it is essential to understand the biochemical responses of plants to water stress in maintaining fruit yield and quality. Citric acid, sucrose, antioxidant activity, and TPC were not affected by the application of studied deficit irrigation strategies (DI). An increase in malic acid and a decrease in glucose was observed for stressed samples (T3 and T4), while a higher number of total volatiles compounds was found for moderate RDI (T2). Using deficit irrigation strategies, the almond yield and quality was not changed, and in fact, some parameters, such as glucose and key volatile compounds, slightly increased under moderate RDI. This finding might encourage farmers to implement these strategies and contribute to sustainable agriculture.

Sensory Profile and Acceptability of HydroSOStainable Almonds

Fresh water availability is considered highly risky because it is a finite resource, and a deficiency in water leads to numerous economic and environmental issues. Agriculture is one of the main consumers of fresh water in practices such as irrigation and fertilization. In this context, the main objectives of this study were (i) to determine the descriptive sensory profiles of four almond types grown using different irrigation strategies and (ii) to study their acceptance in a cross-cultural study (Romania and Spain). Consumers' willingness to pay for hydroSOS almonds was also evaluated. The four irrigation strategies evaluated were a control sample, two samples grown under regulated deficit irrigation strategies (RDI), and a sample grown under a sustained deficit irrigation strategy (SDI). The main conclusion was that neither descriptive nor affective sensory results showed significant differences among treatments. These findings should encourage farmers to reduce their water usage by demonstrating that sensory quality was not significantly affected by any of the studied treatments, compared to the control. Regarding willingness to pay, both Spanish and Romanian consumers were willing to pay a higher price for the hydroSOS almonds.

Consumers' Opinion on Dried Pomegranate Arils to Determine the Best Processing Conditions

Consumers' preference is essential to improve processed food products quality, but small companies sometimes lacks knowledge or tools to develop consumer studies. The aim of the present study was to investigate consumers' insight to recommend the best drying methodology for pomegranate arils. With the aim of providing information that industry can correlate to the drivers of liking, descriptive sensory characteristics, and volatile compounds of the samples were determined and related with consumers' responses. A total of 19 volatiles of dehydrated pomegranate arils were determined using solid-phase microextraction and gas chromatography-mass spectrometry. Partial least square regression (PLS) results indicated that consumers overall liking was positively correlated with "pom ID", "sweet", and "fruity" attributes, and also volatile compounds of the esters family. Overall liking was negatively correlated with the "off-flavor" and "burnt" attributes, related to the furan compounds family. Penalty analysis indicated that the sample corresponding with the current commercial product needed improvement on the "pom ID", "fruity", and "sweetness" parameters. All the samples processed using the proposed new drying techniques were more liked than the commercial sample, highlighting a sample dried using pre-osmotic dehydration in Wonderful concentrate pomegranate juice. PRACTICAL APPLICATION: Consumers' preference is essential to improve processed food products quality, but small companies sometimes lack knowledge or tools to conduct consumer studies. The present study provides useful information to understand consumers' preferences of a healthy product such as pomegranate dehydrated arils. Also, the link of physico-chemical and sensory tools is clearly described, providing information about possible sensory quality indicators.