Apricot Fruit Research Articles

A combination of hot water and abscisic acid (ABA) biosynthesis inhibitor regulates ripening of Japanese apricot (Prunus mume) fruit

A combination of hot water and abscisic acid (ABA) biosynthesis inhibitor regulates ripening of Japanese apricot (Prunus mume) fruit

REMOVAL OF POLLUTANTS FROM SEWAGE WITH GRINDED SHELLS OF APRICOT KERNELS

A review of the literature data on the use of biomass components of apricot trees (Prunusarmeniaca) as a sorption material for the extraction of various pollutants from waste and natural waters is carried out. The parameters of the sorption interaction at which the highest degree of removal of pollutants is achieved are given. It has been shown that it is possible to increase the sorption capacity of apricot biomass components by modifying it with various chemical reagents. It has been determined that the most studied sorption material is the shell of apricot kernels. It is determined that the largest number of publications is devoted to the use of the latter as raw materials for the production of activated carbons. It was revealed that the surface area and the total pore volume of activated carbons from the kernels of apricot fruits depend on the modes of carbonization and activation of raw materials. It is shown that activated carbons are effective sorbents for removing various pollutants (metal ions, dyes, oil and oil products) from aqueous media. It was found that the adsorption isotherms of pollutants are most adequately described in most cases by the Langmuir and Freundlich models, and the kinetics of the process is most often described by the pseudo-second order model.

Diversification and Soil Management Effects on the Quality of Organic Apricots

Nutritional and commercial value of the apricot fruits depends on the interaction among several factors, including the management strategies, the environmental conditions, and the genotype. This study aimed to evaluate the effect of orchard management and pedoclimatic conditions on apricot fruit quality traits (soluble solids, titratable acidity, dry matter and soluble solids and titratable acidity ratio) and phytochemical content (total phenolic content and antioxidant activity). Two apricot cultivars (Kioto* and Pieve*) were subjected to three different organic systems: (i) a standard management (BAU), (ii) an innovative diversified system with reduced tillage based on the natural cover conservation (INC) and (iii) an innovative diversified system with introduction of different cover crops (ICC), for two consecutive years (2019–2020). Overall, besides the effect of the climatic conditions, the multivariate analysis revealed the role of management systems, rather than genotype, on the quality of apricot fruits. In particular, INC soil management positively affected soluble solids, titratable acidity and dry matter parameters, especially in environments with low precipitation and high solar radiation (20.7 ± 1.7 g 100 g−1 FW, 19.9 ± 2.5 g MA 100 g−1 FW and 0.23 ± 0.2 g 100 g−1 FW respectively). In addition, the results indicate that ICC management showed the highest antioxidant values (1.45 ± 0.19 μg of Trolox equivalent (TE) 100 mg−1 FW), especially in the environment with high precipitation. This study was a useful tool for farmer to choose an effective organic system management in order to obtain fruits with high quality parameters.

Yield, Fruit Quality, and Storability of 'Canino' Apricot in Response to Aminoethoxyvinylglycine, Salicylic Acid, and Chitosan.

Ethylene plays a pivotal role in the climacteric fruit ripening and senescence process. The effect of three ethylene inhibitors on the yield, quality, and storability of ‘Canino’ apricot fruit was studied. Foliar sprays of distilled water (control), aminoethoxyvinylglycine (AVG) (150 and 100 mg·L−1), salicylic acid (SA) (4 and 2 mM), and chitosan (2.5% and 1.5%) were applied 30 and 15 days before harvest. Results indicated that the high concentrations of AVG and SA recorded the lowest percentage of preharvest fruit drop and, hence, the highest yield. Trees receiving either concentration of AVG showed the highest fruit firmness. High concentrations of all three ethylene inhibitors reduced fruit weight loss, total carotenoids, and soluble solid content (SSC), but increased total acidity (TA) during cold storage (2 °C). A high score of overall taste acceptability was observed with a higher concentration of SA, which was also recorded the lowest fruit malondialdehyde content (MDA) at harvest and during storage. The highest concentrations of SA and chitosan recorded no decay for 28 days of storage. Gene expression analysis reflected higher expression of PaACS1 gene with the highest concentrations of ethylene inhibitors, suggesting that SA (4 mM) is recommended for optimal yield, quality, and storability of ‘Canino’ apricot fruit grown under Egyptian conditions.

Determining the Optimum Conditions for Extracting Carotenoids from Syrian Apricot Fruits

The aim of this research is to extract carotenoids from apricot fruits using a food solvent (ethanol) and a non-food solvent (propanol). In addition, it aims to study the effect of different extraction conditions, i.e., the extraction temperature (20-40-60)°C and the extraction times (4-8-12) hours, on the carotenoids yield in order to improve and develop extraction methods. The extracted carotenoids were determined using high-performance liquid chromatography (HPLC), and the studied carotenoids are α-carotene and β-carotene. It was found that β-carotene constitutes about 80% of the total carotenoids in apricots. The results indicated that the extraction yield using ethanol was low compared to the extraction yield using propanol. Propanol is the most suitable solvent for carotenoids extraction in comparison with ethanol. The temperature also had a significant effect on the extraction yield; at 20°C the extraction yield was very low, and 60°C was the optimum temperature for the extraction of carotene. The extraction yield significantly increased with time in the first hours of extraction, and there was no significant effect from increasing the extraction time for a period of 6-8 hours. Moreover, the pretreatment of fruits by freezing accelerated the extraction process and increased the extraction yield. The optimum conditions for extracting carotenoids were determined in the conditions of food extraction; the optimum conditions for extracting carotenoids are: extraction at 60°C for three hours with pretreatment by freezing as the extraction rate reached up to 6.36 mg/100 g using ethanol as a food solvent.

Melatonin and 1‐methylcyclopropene treatments on delay senescence of apricots during postharvest cold storage by enhancing antioxidant system activity

The effect of melatonin (MT) dipping and 1-methylcyclopropene (1-MCP) fumigation either individually or combined, on reducing delaying fruit senescence in apricot fruit was investigated. The results showed that the individual and combined MT and 1-MCP treatments maintained the quality of apricot fruits after harvest and reduced fruit softening, rot, and weight loss. This was mainly attributed to the high levels of ascorbic acid content, total phenol content, and total flavonoid content, as well as the upregulation of peroxidase, superoxide dismutase, and catalase enzyme activities, which reduced the active oxygen content. Besides, 1-MCP and MT in individual or in combined treatments suppressed the process of membrane lipid peroxidation by inhibiting the malondialdehyde content and lipoxygenase activities, contributing to delaying the senescence of apricot fruits. Among these three treatments, 1-MCP was the best method to delay the postharvest senescence of apricots. Novelty impact statement The individual and combined MT and 1-MCP treatments had positive effect on apricot fruits quality during cold storage. The individual and combined MT and 1-MCP treatments apparently enhanced the activity of enzymatic antioxidants and nonenzymatic antioxidants. Decreased H2O2 generation was observed in the individual and combined MT- and 1-MCP-treated fruits during storage time.

Identification of Key Genes Controlling Carotenoid Metabolism during Apricot Fruit Development by Integrating Metabolic Phenotypes and Gene Expression Profiles.

To explore the metabolic basis of carotenoid accumulation in different developmental periods of apricot fruits, targeted metabonomic and transcriptomic analyses were conducted in four developmental periods (S1-S4) in two cultivars (Prunus armeniaca cv. "Kuchebaixing" with white flesh and P. armeniaca cv. "Shushangganxing" with orange flesh) with different carotenoid contents. 14 types of carotenes and 27 types of carotene lipids were identified in apricot flesh in different developmental periods. In S3 and S4, the carotenoid contents of the two cultivars were significantly different, and β-carotene and (E/Z)-phytoene were the key metabolites that caused the difference in the total carotenoid content between the examined cultivars. Twenty-five structural genes (including genes in the methylerythritol 4-phosphate and carotenoid biosynthesis pathways) related to carotenoid biosynthesis were identified among the differentially expressed genes in different developmental periods of the two cultivars, and a carotenoid metabolic pathway map of apricot fruits was drawn according to the KEGG pathway map. The combined analysis of carotenoid metabolism data and transcriptome data showed that PSY, NCED1, and CCD4 were the key genes leading to the great differences in the total carotenoid content. The results provide a new approach to study the synthesis and accumulation of carotenoids in apricot fruits.

Effect of Methyl Jasmonate, Cytokinin, and Lavender Oil on Antioxidant Enzyme System of Apricot Fruit (Prunus armeniaca L.)

Various treatments are carried out in order to extend both the shelf life and storage life of fresh fruit and vegetables after harvest and among them non-toxic for humans, environmentally and economically friendly alternative treatments are gained more importance. In the current study, methyl jasmonate (MeJA), cytokinin, and lavender oil which are eco-friendly and safe for human health were applied on apricot fruit. The treated fruit were stored at 0 °C and 90–95% relative humidity for 25 days and catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) enzyme activities and lipid peroxidation of apricots after treatments were studied. According to the findings obtained from the study, it was observed that 5 ppm cytokinin and 1000 ppm lavender oil treatments of apricot fruit gave better APX and CAT enzyme activity, respectively. In addition, better SOD enzyme activity in fruit was obtained with MeJA + lavender oil treatments. As a result, it can be emphasized that the product quality of apricot fruit is preserved as both the eco-friendly application of MeJA, cytokinin, and lavender oil separately from each other and the treatment of combinations between these compounds activate the enzymatic antioxidant defense systems of apricot fruit after harvest.

Effects of 1‐MCP treatment on volatile compounds and quality in Xiaobai apricot during storage at low temperature

The objective of this study was to investigate the effects of 1-methylcyclopropene (1-MCP) treatment on the storage quality and volatile compounds of Xiaobai apricot fruit stored at 4°C. Three groups of apricot fruit were set in a 1 m3 container and treated with 0.5, 1, 1.5 μl/L of 1-MCP for 20 hr at 20°C, respectively. The physiological parameters and volatile compounds of 1-MCP-treated and untreated apricot fruit were examined. Twenty-eight volatile compounds were isolated and identified, and the main aroma compounds were determined to be linalool, α-terpenol, 6-methyl-5-hepten-2-one, theaspirane, benzaldehyde, nonanal, linalyl formate, butyl acetate, and hexyl acetate. The result showed that 1 μl/L of 1-MCP treatment had the most effective impact on delaying the ethylene production, respiration rates, soluble solids content, and maintaining firmness, titratable acidity, and ascorbic acid content, and 0.5 and 1 μl/L inhibited the production of most volatile compounds during storage. Novelty impact statement 1-MCP treatment can keep apricot fruit in good quality, but decreased the production of Volatile compounds. Linalyl formate and the aspirane were isolated and identified, and these were hardly found in apricot fruit in the previous report. A high concentration of 1-MCP treatment may promote the production of volatile compounds.

Transcriptome analysis insight into ethylene metabolism and pectinase activity of apricot (Prunus armeniaca L.) development and ripening

Ethylene metabolism is very important for climacteric fruit, and apricots are typical climacteric fruit. The activity of pectinase is closely related to fruit firmness, which further affects fruit quality. To better understand ethylene metabolism, pectinase activity and their molecular regulation mechanisms during the development and ripening of apricot fruit, ethylene metabolism, pectinase activity and the “Luntaibaixing” apricot fruit transcriptome were analyzed at different developmental stages. Ethylene metabolic precursors, enzyme activities and ethylene release increased during fruit development and ripening, with significant differences between the ripening stage and other stages (P < 0.05). Fruit firmness decreased significantly from the S1 to S5 stages, and polygalacturonase, pectin methylesterase, and pectin lyase activities were significantly higher in the S5 stage than in other stages. RNA sequencing (RNA-seq) analysis of fruit resulted in the identification of 22,337 unigenes and 6629 differentially expressed genes (DEGs) during development and ripening, of which 20,989 unigenes are annotated in public protein databases. In functional enrichment analysis, DEGs among the three stages were found to be involved in plant hormone signal transduction. Four key genes affecting ethylene metabolism, six key ethylene signal transduction genes and seven genes related to pectinase in apricot fruit were identified by KEGG pathway analysis. By RNA-sequencing, we not only clarified the molecular mechanism of ethylene metabolism during the ripening of "Luntaibaixing" apricot fruit but also provided a theoretical basis for understanding pectin metabolism in apricot fruit.

Pre-Harvest Oxalic Acid Application Improves Fruit Size at Harvest, Physico-Chemical and Sensory Attributes of ‘Red Flesh’ Apricot During Fruit Ripening

Apricot is a highly nutritive stone fruit which ripens quickly after harvest and exhibits rapid fruit quality deterioration at ambient conditions. The current research work was executed to evaluate the effect of pre-harvest application of oxalic acid (OA); (0, 0.5, 1, and 2mM) on fruit quality of ‘Red Flesh’ apricot during fruit ripening at shelf under ambient conditions (25±1 °C; 60-65% RH). Fruit size, average fruit weight, fruit juice percentage was determined at harvest. While, fruit weight loss, fruit colour, fruit firmness, titratable acidity (TA), soluble solid contents (SSC), ratio of SSC to TA, ascorbic acid, total phenolics content (TPC), anti-oxidative scavenging activity (ASA), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) enzymes activity were determined during fruit ripening. Fruit sensory attributes (fruit pulp colour, fruit taste, fruit flavour and overall acceptability were determined at fruit ripening. Pre-harvest application of 2mM-OA was found the most effective in improving fruit size, average fruit weight, juice percentage at harvest, about 5%, 6% and 15% higher than control, respectively. Additionally, pre-harvest application of 2mM-OA retained higher fruit firmness, ascorbic acid, TPC, ASA and activities of POD, CAT enzymes in apricot fruit during fruit ripening at ambient conditions. On day-5 of fruit ripening 2mM-OA-treated apricot fruit exhibited about 28%, 20%, 17%, 7%, 9% and 23% higher fruit firmness, ascorbic acid, TPC, ASA and activities of POD, CAT enzymes, respectively as compared to control. Moreover, significant lower fruit weight loss (35%), SSC (20%) and SSC:TA ratio (30%) were exhibited by the apricot fruit treated with 2mM-OA than unsprayed apricot fruit. However, fruit treated with 1 mM-OA exhibited better fruit sensory attributes compared to other treatments at fruit ripening. Conclusively, pre-harvest application of 2 mM-OA improved the fruit size, delayed fruit ripening, and retained higher fruit antioxidants of apricot at ambient conditions.

Use of black cumin oil and liquorice syrup to maintain the postharvest quality of fully ripe apricot fruits var. ‘Thyrinte’

Use of black cumin oil and liquorice syrup to maintain the postharvest quality of fully ripe apricot fruits var. ‘Thyrinte’

Proanthocyanidin in the fruit of Japanese apricot (Prunus mume Sieb. et Zucc.) and their structural estimation by HPLC-ESI-MS/MS

Proanthocyanidins (PAs) contribute to the quality factors and health benefits of several Rosaceae fruits. Ume, also known as Japanese apricot (Prunus mume Sieb. Et. Zucc), is one of the most popular fruit trees grown in Japan, and its processed products are employed as a folk remedy in eastern Asian countries. However, the information available regarding the PAs present in the fruit remains limited. In this study, we analyzed the PAs and phenolic acid derivatives present in the fruit of ‘Nnanko,’ the most common cultivar, and found that the flesh tissue of the mature fruit contained levels of PAs similar to those of the hydroxycinnamic acids. The concentration of PAs in the endocarp tissue of the mature fruit was approximately 14 times higher than that of the flesh tissue. We also estimated the chemical structures of the PAs from the flesh and the endocarp by HPLC-ESI-MS/MS. Although 13 kinds of PAs, including 2 monomers, 4 B-type dimers, 3 A-type dimers, 2 B-type trimers, 1 A-type trimer, and 1 B-type tetramer were detected in the flesh, only 2 monomers, 1 B-type dimer, and 2 A-type dimers were detected in the endocarp. All PAs detected in the endocarp were also present in the flesh.

Comparison of calcium and ultrasonic treatment on fruit firmness, pectin composition and cell wall-related enzymes of postharvest apricot during storage.

This study was conducted to examine the effects of calcium treatment (2%, 20min) and ultrasonic treatment (400W, 20min) on postharvest apricot fruit during storage. The results showed that after calcium and ultrasonic treatment, compared with the control, the firmness of apricot fruit increased by 41.53% and 3.83% at 16 d, butjuice yield and water-soluble pectin (WSP) content decreased by 8.26% and 3.55%, 28.57% and 4.08%, respectively. Both calcium and ultrasonic treatment were more effective in reducing polygalacturonase (PG), β-Galactosidase (β-Gal), pectin methylesterase (PME), polyphenol oxidase (PPO)and peroxidase (POD)activity. Moreover, fruit firmness was significantly negatively correlated with juice yield, WSP and PPO, and positively correlated with PG and β-Gal, PPO and POD. In contrast, calcium treatment was more effective than ultrasonic treatment in delaying postharvest softening of apricot.

New Insights of Potassium Sources Impacts as Foliar Application on 'Canino' Apricot Fruit Yield, Fruit Anatomy, Quality and Storability.

This is the first report to study the impacts of potassium sources on apricot fruit yield, quality and storability as a preharvest foliar application. Five sources of potassium (K-humate, K-sulphate, K-nitrate, K-silicate and K-citrate), plus water as a control treatment, were applied individually at 0.2% three times on ‘Canino’ apricot over the 2019 and 2020 seasons. The results showed that all potassium salts, applied foliarly, have potential to improve yield, fruit color, and some fruit physical attributes, such as: weight, size and firmness, as well as a reduced lipid peroxidation, accompanied by a low fruit malondialdehyde content reflected in a high tolerance during storage. The K-nitrate treatment was more effective in the improvement of fruit yield, preharvest quality parameters and keeping fruit postharvest quality characteristics from sharp decline during cold storage. Concerning fruit anatomy, K-nitrate and K-citrate showed thicker cuticle and epidermal parenchyma cell diameters, while the K-silicate induced the highest cell wall thickness. K-nitrate was the most economical, and could be recommended for apricot growers in the Nubaria region of Egypt.

Near freezing temperature storage alleviates cell wall polysaccharide degradation and softening of apricot (Prunus armeniaca L.) fruit after simulated transport vibration

The commodity attribute of apricot fruits may greatly decline during transportation and storage. Although the efficacy of near freezing temperature (NFT) storage for maintaining apricot quality has been reported, previous studies did not investigate the effects on cell wall structure, cell ultrastructure, and the composition and activities of cell wall degrading enzymes after simulated transport vibration. The objective of the present study was to evaluate the cell wall metabolism and postharvest quality of ‘Xiaobai’ apricots during storage at 4–6 °C, 1–2 °C, or NFT for 49 d after simulated transport vibration. Quality parameters, cell wall composition, cell wall degrading enzymes, and cell ultrastructure were analyzed. The results indicated that NFT storage considerably delayed the senescence of apricots, including the inhibition of loss of firmness and decrease in total soluble solid content (TSS), titratable acid (TA) content and L*, a*, b*, compared with storage at 4–6 °C and 1–2 °C after simulated transport vibration. NFT storage markedly suppressed the respiration rate and maintained a higher content of ascorbic acid and lower membrane permeability during the storage period compared with storage at 1–2 °C and 4–6 °C. Furthermore, NFT storage could delay apricot fruit softening after simulated transport vibration, as indicated by delayed the degradation of Na2CO3-soluble pectin (NSP) and cellulose content, and slowed down the increase in water-soluble pectin (WSP) and chelate-soluble pectin (CSP) of cell walls, maintained lower pectin methylesterase (PME) and polygalacturonase (PG) activity, and inhibited the increase in cellulase and β-galactosidase (β-Gal) activity compared with storage at 4–6 °C and 1–2 °C. Microscopic observation showed that NFT storage delayed the degradation of pectin fraction and protected the plant cell wall structure. In conclusion, NFT storage changes the cell wall structure and the composition and activities of cell wall degrading enzymes in apricot fruits. These results suggested that NFT storage is an effective method to delay the softening process and preserve the quality of apricots after simulated transport vibration.

Nanocapsules of oregano essential oil preparation and characterization and its fungistasis on apricot fruit during shelf life

Oregano essential oil nanocapsules (OEO-NPs) were successfully prepared via a complex coacervation method. The results of this study showed that the percentage encapsulation of the OEO-NPs prepared by the best technological process was 88.3%, the loading amount of oregano essential oil (OEO) was 74.36%, and the average particle size was 135 nm. OEO-NPs exhibited better spherical and regular surface structure, higher thermal stability, and slow-release performance. In addition, the 4% OEO-NPs showed better fungistatic effect and reduced decay rate, which compared with the control, 2% and 8% OEO-NPs treatments, during apricot shelf life; 4% OEO-NPs also increased peroxidase, L-phenylalanine ammonialyase, β-1,3-glucanase, catalase and chitinase activities, while reduced the polyphenol oxidase activities during fruit shelf life than that in control. These results provided a new idea for the development of a slow-release fungistatic agent based on plant essential oils. Novelty impact statement Oregano essential oil nanocapsules (OEO-NPs) possessed higher thermal stability and slow-release performance. 4% OEO-NPs showed a better fungistatic effect and reduced apricot fruit decay rate during shelf life. OEO-NPs provided a new idea for the development of green and slow-release fungistatic agent.

Comparative assessment of polyphenolics’ content, free radicals’ scavenging and cellular antioxidant potential in apricot fruit

Natural antioxidants possess health beneficial properties and are being substantially used in foods, cosmetics and pharmaceutical products. Polyphenolics content, antioxidant activity and HepG2 liver cancer cells’ inhibition potential were determined and compared in the fruit of apricot cultivars collected from lower Himalayan region of Pakistan using standard analytical procedures. Comparatively, fruit of AP3 cultivar had highest levels of total phenolics and total flavonoids contents (220.5 ± 15.9 mgGAE/100 g and 382.0 ± 18.0 mgQE/100 g, respectively) on fresh weight basis. Fruit of the same cultivar had maximum DPPH scvenging potential (94.24 ± 4.55%), oxygen radicals absorbance capacity at 4.71 ± 0.12 mMolTE/100 g and inhibition of HepG2 cancer cells (45.80 ± 4.01 µMolQE/100 g). Though, fruit of AP4 cultivar was rich in vanillic acid, caffeic acid, vanillin, epi-catechin and quercetin, but had relatively low antioxidant and anticancer potential. Disparities in the phytochemical composition and properties of apricot fruit are attributed to genetic differences and growing conditions. Total phenolics, total flavonoids and caffic acid depicted highly significant positive association (˃90%) with ORAC, CAA and FRAP. Our findings suggest that being a rich source of health beneficial secondary metabolites, apricot fruit of Himalayan region of Pakistan could contribute considerably in socio-economic development of the local communities and as a functional food in regional and global markets.

Temporal Patterns and Inter-Correlations among Physical and Antioxidant Attributes and Enzyme Activities of Apricot Fruit Inoculated with Monilinia laxa under Salicylic Acid and Methyl Jasmonate Treatments under Shelf-Life Conditions.

Monilinia laxa causes serious postharvest damage on apricot fruits under shelf-life storage conditions. Plant elicitors of methyl jasmonate (MeJA) and salicylic acid (SA) can reduce this damage, and their research can explain the background of the plant defense physiological processes in M. laxa-infected fruits. The aims of this study were: (i) to evaluate the effect of various concentrations of MeJA and SA on brown rot incidence (BRI) and lesion diameter (LD) of apricot fruits; (ii) to measure the temporal patterns for the effect of 0.4 mmol L−1 MeJA and 2 mmol L−1 SA treatments on BRI, LD and seven fruit measures (fruit firmness (FF), lignin content (LC), total soluble phenol content (TSPC), total antioxidant capacity (TAC) and enzyme activities of PAL, POD and SOD) in treatments of M. laxa-inoculated versus (vs.) non-inoculated fruits over an eight-day shelf-life storage period; and (iii) to determine inter-correlations among the seven fruit measures for MeJA and SA treatments. Both MeJA and SA significantly reduced BRI and LD. LC, FF, TAC, TSPC, as well as SOD and PAL activities in the MeJA and SA treatments were higher than the water-treated control in most assessment days and both inoculation treatments. In both inoculation treatments, the activity of POD in the SA-treated fruits was higher than MeJA-treated and control fruits at all dates. In MeJA vs. SA and inoculated vs. non-inoculated treatments, six variable pairs (FF vs. TSPC, FF vs. TAC, TAC vs. PAL, PAL vs. POD, PAL vs. SOD, and POD vs. SOD) showed significant inter-correlation values. Principal component analyses explained 96% and 93% of the total variance for inoculated and non-inoculated treatments, respectively. In inoculated treatments, both PC1 and PC2 explained 41% of the total variance and correlated with FF, TSPC and TAC and with PAL, SOD and POD, respectively. In non-inoculated treatments, PC1 and PC2 explained 49% and 44% of the total variance and correlated with LC, PAL, POD and SOD and with FF, TSPC and TAC, respectively. It can be concluded that MeJA and SA are useful in the practice to enhance the plant defense system against brown rot by reducing fungal growth and by improving physical and antioxidant attributes (FF, LC, TAC and TSPC) and the activity of defense-related enzymes (PAL, POD and SOD) in apricot fruits during shelf-life storage conditions.

Evaluation of Protein and Antioxidant Content in Apricot Kernels as a Sustainable Additional Source of Nutrition

Apricot fruits are a favorite for consumption; however, their kernels are a rich source of nutritionally interesting substances, too. Nevertheless, in processing of apricots, the kernels remain often unused. In this study, 32 cultivars of different origin were analyzed for their protein content and content of secondary metabolites (phenolics and flavonoids). The weight and taste of kernels were assessed and these data were summarized for an evaluation of the attractiveness of the studied apricot kernels. Results showed that the protein content of kernels ranged from 14.56% to 28.77% and did not depend on the origin or weight of kernel, or taste. In addition, total phenolic (63.5–1277.3 mg GAE/100 g DW) and total flavonoid (0–153.1 mg CE/100 g DW) contents and antioxidant capacity (483.4–2348.4 mg TE/100 g DW) were measured in kernels. In conclusion, the Czech hybrids LE-5959, LE-5500 and French cultivar Koolgat are prospective for kernel processing and consumption because of their high protein content and sweet taste. Hybrid LI-3-6, originating in China, showed high protein content as well but because of bitter taste could be useful rather in medicine.