Fruit Acidity Research Articles

Foliar application of sodium selenite affects the growth, antioxidant system, and fruit quality of strawberry.

Selenium (Se) plays a vital role in various physiological processes in plants and is regarded as an essential micronutrient for human health as well. In this study, sodium selenite solution at 10, 40, 70, and 100 mg·L-1 concentrations was foliar sprayed, and the strawberry plant growth, antioxidant system, and fruit quality with an emphasis on sugar and acid content were assessed. The results showed that 10 mg·L-1 of sodium selenite treatment promoted plant growth, while all the treated concentrations could enhance photosynthesis, the antioxidant system in leaves, the content of Se, and ascorbic acid in fruits. More importantly, 40 mg·L-1 sodium selenite treatment significantly increased fruit weight, total soluble solid, total phenolic content, and anthocyanins, as well as improved the shape index. Furthermore, it decreased the total flavonoid and proanthocyanidin content. Particularly, sodium selenite treatment at 40 and 70 mg·L-1 largely increased the ratio of soluble sugars to titratable acid. The changes of predominant sugars and organic acids during fruit development were further investigated. The sucrose, fructose, and glucose content was upregulated by sodium selenite treatment through upregulating the activities of sucrose phosphate synthase (SPS) and acid invertase, as well as the FaSPS expression. In addition, sodium selenite treatment inhibited the activity of citrate synthase and phosphoenolpyruvate carboxylase, rather than modulating their transcript levels to reduce the citric acid content. This work presented a potentially efficient approach to enhance plant growth and fruit quality and supplement Se in strawberry, providing insights into the mechanism of regulating sugar and acid metabolism by Se.

Physiological and Transcriptomic Analysis of Citrus Fruit Segment Drying under Facility-Forcing Cultivation

Facility-forcing cultivation could effectively improve the quality of ‘Beni Madonna’ citrus (Citrus nankao × C. amakusa) and advance the ripening period. However, segment drying (KS) before harvest caused fruit quality deterioration and commodity value loss. In this research, we investigated the physiological and molecular characteristics involved in citrus segment drying under facility-forcing cultivation. The juice yield, sugar, acid, vitamin C, and lignin contents in KS fruits were significantly decreased, and the contents of pectin and cellulose were significantly increased. The relative contents of abscisic acid and abscisic acid glucosyl ester in KS fruits were significantly decreased. A total of 1215 differentially expressed genes (DEGs) were screened by transcriptome sequencing. DEGs were significantly enriched in water metabolism, sugar metabolism, transportation, cell wall and phenylpropanoid biosynthesis, and plant hormone signal transduction. The decrease in water absorption and sugar synthesis, the increase of pectin and cellulose synthesis, and the decrease in ABA accumulation may be the main reasons that cause citrus fruit segments to dry under facility-forcing cultivation.

Assessment of glycemic index of the unripe green papaya in mice

Papaya (Carica papaya L.) is a rich-nutrition fruit include vitamins (A, B and C), carbohydrates, proteins, alkaloids, proteolytic enzymes, and benzyl isothiocyanate. Papaya contains papain, which helps strengthen the constitution of diabetes patients. Its water-soluble fiber can stabilize blood sugar levels, reducing the risk of complications. Papaya has benefits such as lowering blood lipids and softening blood vessels due to the fruit acids it contains, which is advantageous for patients with diabetes complicated by hypertension, arteriosclerosis, and dyslipidemia. Additionally, the proteolytic enzymes in papaya are beneficial for the digestive system. Unripe green bananas have been found to contain a significant amount of resistant starch, giving them potential as a low glycemic index (GI) food. Therefore, the aim of this study was to determine the effects of unripe green papaya on blood glucose regulation. The blood glucose values were measured in C57BL/6 mice before and within 120 minutes after consuming 50 mg of glucose and the grated unripe green papaya containing 50 mg of starch was conducted to calculate the incremental area under the curve (IAUC) for blood glucose changes post-consumption of glucose and the grated unripe green papaya. The results showed that the average IAUC for the grated unripe green papaya was 11,176.67, while the average IAUC for glucose was 7,666.25. According to the GI calculation formula, GI of the grated unripe green papaya was determined to be 146. Therefore, based on the results of this study, these results will be used as the basis for the development of related blood glucose regulation products of the unripe green papaya (Carica papaya L.) in the future.

Analysis of Active Compounds in Hawthorn Species Widespread in Northwestern Syria

The research was conducted during the year 2022 to estimate the most important active compounds in the different plant parts of some types of hawthorns (Crataegus L.) widespread in northwestern Syria (Aronia, Yellow Azarolus, Red Azarolus, and Monogyna). The plant material was collected during the growth period. Flavonoids were estimated in the dry matter of the leaves, flowers, and fruits of the studied hawthorn types, vitamin C in the dry flowers and fresh fruits, carotenoids in the dry fruits, total acidity (TA%), and total soluble solids (TSS%) in the fresh fruits. The results showed that the value of flavonoids in the leaves reached 29.66, 15.76, 14.42, and 14.66 mg/g DM in the studied hawthorn types Monogyna, Aronia, Red Azarolus, and Yellow Azarolus, respectively. The leaves outperformed the flowers and fruits in their flavonoid content in most types, as the average flavonoid content of the leaves, flowers, and fruits in the different types was 18.60, 17.71, and 10.90 mg/g DM, respectively. The highest value of flavonoids (29.66 kg/g) was in the leaves of the Monogyna type, and the lowest value (6.23 mg/g) was in the fruits of the Red Azarolus type. As for vitamin C in the dried flowers of the different types, its value reached 1018.6, 917.5, 814.9, and 799.1 mg/100g, while the value of vitamin C in fresh fruits was 11, 8.14, 7.04, and 6. 53 mg/g, in Monogyna, Aronia, Yellow Azarolus and Red Azarolus, respectively (in dried flowers and fresh fruits). The Monogyna type outperformed the other types of vitamin C content, whether in dried flowers or fresh fruits. As for carotenoids, the values were 0.202, 0.077, 0.093, and 0.156 mg/cm³, respectively, for the types Monogyna, Red Azarolus, Yellow Azarolus, and Aronia. The Monogyna type outperformed the other types in the carotenoid content of its fruits. As for the total acidity, the Red Azarolus type outperformed the other types. The total acidity values were 2.54, 1.94, 1.8, and 0.46% for Red Azarolus, Yellow Azarolus, Aronia, and Monogyna, respectively. Finally, there were no significant differences between the total soluble solids content of the fruits of the different types, as the TSS values reached 24.60, 23.33, 21.27, and 20.97%, in the Red Azarolus, Yellow Azarolus, Monogyna, and Aronia types. Respectively.

Enhancing the Storage Longevity of Apples: The Potential of Bacillus subtilis and Streptomyces endus as Preventative Bioagents against Post-Harvest Gray Mold Disease, Caused by Botrytis cinerea.

Gray mold, caused by Botrytis cinerea Pers. Fr., is one of the most vital plant diseases, causing extensive pre- and post-harvest losses in apple fruits. In the current study, we isolated and identified two potential endophytic bioagents, Bacillus subtilis and Streptomyces endus. Both bioagents exhibited a potent fungistatic effect against B. cinerea under both in vitro and in planta conditions. Moreover, two experiments were carried out; (i) the first experiment was conducted at room temperature after artificial inoculation with B. cinerea to monitor the progression of the infection and the corresponding biochemical responses of the apples. Our in vivo findings showed that the treated B. cinerea-infected apple fruits with the cell-free bacterial filtrate of B. subtilis and S. endus (dipping or wrapping) significantly reduced the rotten area of the treated apple at room temperature. Additionally, B. subtilis and S. endus enhanced the enzymatic (POX and PPO) and non-enzymatic (phenolics and flavonoids) antioxidant defense machinery in treated apples. (ii) The second experiment focused on the preventive effects of both bioagents over a 90-day storage period at 1 °C of healthy apples (no artificial inoculation). The application of both bacterial filtrates prolonged the storage period, reduced the relative weight loss, and maintained high-quality parameters including titratable acidity, firmness, and total soluble solids of apple fruits under cold storage at 1 °C. The Kaplan-Meier analysis of rotten apples over 90 days during cold storage showed that the treated apples lasted longer than the non-treated apples. Moreover, the lifespan of apple fruits dipped in the culture filtrate of B. subtilis, or a fungicide, was increased, with no significant differences, compared with the non-treated apples. The current results showed the possibility of using both bioagents as a safe and eco-friendly alternative to chemical fungicides to control gray mold disease in apples.

Effect of Near-Freezing Temperature Storage on the Quality and Organic Acid Metabolism of Apple Fruit

Organic acids play critical roles in fruit physiological metabolism and sensory quality. However, the conventional storage of apple fruit at 0 ± 0.1 °C cannot maintain fruit acidity efficiently. This study investigated near-freezing temperature (NFT) storage for ‘Golden Delicious’ apples, and the quality parameters, organic acid content, and malate metabolism were studied. The results indicate that NFT storage at −1.7 ± 0.1 °C effectively maintained the postharvest quality of apple fruit when compared to traditional storage at 0 ± 0.1 °C. Fruit that underwent NFT storage showed a better appearance and lower respiratory rate, ethylene production, weight loss, and malondialdehyde (MDA) content but higher firmness and soluble solids content. Further, fruit after NFT storage contained higher titratable acid (18.75%), malate (51.61%), citrate (36.59%), and succinate (2.12%) content when compared to the control after 250 days. This was achieved by maintaining higher cytosolic NAD-dependent malate dehydrogenase (cyNAD-MDH), phosphoenolpyruvate carboxylase (PEPC), vacuolar H+-ATPase (V-ATPase), and vacuolar inorganic pyrophosphatase (V-PPase) activities that promote malate biosynthesis and accumulation while inhibiting enzyme activity that is responsible for malate decomposition, including phosphoenolpyruvate carboxylase kinase (PEPCK) as well as the cytosolic NAD phosphate-dependent malic enzyme (cyNADP-ME). Further, storage at NFTs maintained a higher expression of malate biosynthesis-related genes (MdcyNAD-MDH and MdPEPC) and transport-related genes (MdVHA and MdVHP) while suppressing malate consumption-related genes (MdcyME and MdPEPCK). The results demonstrate that NFT storage could be an effective application for apple fruit, which maintains postharvest quality and alleviates organic acid degradation.

A sensitive method for the determination of per- and polyfluoroalkyl substances in food and food contact material using high-performance liquid chromatography coupled with tandem mass spectrometry

Dietary intake is the major pathway of human exposure to per- and polyfluoroalkyl substances (PFAS). Due to their generally very low concentrations in food, especially for foods of plant origin, and their toxicological relevance, demand is growing for improved selective and sensitive analytical methods for the determination of PFAS in the lower ng/kg range. The relevance is pointed out due to the fact that the European Commission has published limits of quantification (LOQs) in the lower ng/kg range for different food matrices in Recommendation (EU) 2022/1431 on the monitoring of perfluoroalkyl substances in food. For example, LOQs of 2 ng/kg for perfluorooctanesulfonic acid (PFOS), 1 ng/kg for perfluorooctanoic acid (PFOA), 1 ng/kg for perfluorononanoic acid (PFNA) and 4 ng/kg for perfluorohexanesulfonic acid (PFHxS) in fruit, vegetables and baby foods are required. A new, very sensitive method is presented here for the determination of 22 PFAS in food and food contact materials. The method is based on liquid-solid extraction and automated clean-up using two solid phase extraction techniques. The analytes are separated and detected by HPLC-MS/MS. A limit of detection (LOD) of 0.33 ng/kg and an LOQ of 1.0 ng/kg are attained for plant foods such as fruits and vegetables as well as for milk and baby food. For foods of animal origin such as egg, meat, fish and paper-based food contact materials an LOD of 1.6 ng/kg as well as an LOQ of 5.0 ng/kg are attained. PFOS and PFOA were the most abundant compounds in the food samples with concentration as high as 1,051 ng/kg of PFOA in sea weed samples and 772 ng/kg of PFOS in eggs samples. In food contact material samples, higher levels were found with a maximum of 310,000 ng/kg PFHxA. In sum the presented method firstly allows determination of PFAS in a wide variety of foodstuffs and paper-based food contact materials at EU-required concentration ranges.

Performance of Different Hybrids of Chilli (Capsicum annuum L) under Prayagraj Agro-Climatic Condition

The experiment was conducted on Performance of hybrids of chilli with eight hybrids during 2023-2024 at the Vegetable Research Field of Department of Horticulture, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj. The observations were taken and recorded on various growth, yield and quality contributing parameters. The results from the present investigation revealed that based on the mean performance of eight hybrids of Chilli, hybrids 21CHIHYB-3 and 21CHIHYB-7 were found superior in terms of Fruit yield (q/ha). 21CHIHYB-1 was found to be best in terms of growth parameters (plant height, number of branches). However, on the basis of earliness parameters (flowering), hybrid 21CHIHYB-2 performed best. On the basis of Ascorbic Acid in Fruits, 21CHIHYB-1 is the best and the Total soluble solids was found best in 21CHIHYB-7. The highest gross return was found in the 21CHIHYB-3 and the B:C ratio was found in the same with 3.3. The experiment was laid out in Randomized Block Design with 3 replications and 8 varieties of Chilli.

Haplotype-resolved T2T genome assemblies and pangenome graph of pear reveal diverse patterns of allele-specific expression and the genomic basis of fruit quality traits

Hybrid crops often exhibit increased yield and greater resilience, yet the genomic mechanism(s) underlying hybrid vigor or heterosis remain unclear, hindering our ability to predict the expression of phenotypic traits in hybrid breeding. Here, we generated haplotype-resolved T2T genome assemblies of two pear hybrid varieties, ‘Yuluxiang’ (YLX) and ‘Hongxiangsu’ (HXS), which share the same maternal parent but differ in their paternal parents. We then used these assemblies to explore the genome-scale landscape of allele-specific expression (ASE) and create a pangenome graph for pear. ASE was observed for close to 6000 genes in both hybrid cultivars. A subset of ASE genes related to aspects of fruit quality such as sugars, organic acids, and cuticular wax were identified, suggesting their important contributions to heterosis. Specifically, Ma1, a gene regulating fruit acidity, is absent in the paternal haplotypes of HXS and YLX. A pangenome graph was built based on our assemblies and seven published pear genomes. Resequencing data for 139 cultivated pear genotypes (including 97 genotypes sequenced here) were subsequently aligned to the pangenome graph, revealing numerous structural variant hotspots and selective sweeps during pear diversification. As predicted, the Ma1 allele was found to be absent in varieties with low organic acid content, and this association was functionally validated by Ma1 overexpression in pear fruit and calli. Overall, these results reveal the contributions of ASE to fruit-quality heterosis and provide a robust pangenome reference for high-resolution allele discovery and association mapping.

A wild melon reference genome provides novel insights into the domestication of a key gene responsible for melon fruit acidity.

A wild melon reference genome elucidates the genomic basis of fruit acidity domestication. Structural variants (SVs) have been reported to impose major effects on agronomic traits, representing a significant contributor to crop domestication. However, the landscape of SVs between wild and cultivated melons is elusive and how SVs have contributed to melon domestication remains largely unexplored. Here, we report a 379-Mb chromosome-scale genome of a wild progenitor melon accession "P84", with a contig N50 of 14.9Mb. Genome comparison identifies 10,589 SVs between P84 and four cultivated melons with 6937 not characterized in previously analysis of 25 melon genome sequences. Furthermore, the population-scale genotyping of these SVs was determined in 1175 accessions, and 18 GWAS signals including fruit acidity, fruit length, fruit weight, fruit color and sex determination were detected. Based on these genotyped SVs, we identified 3317 highly diverged SVs between wild and cultivated melons, which could be the potential SVs associated with domestication-related traits. Furthermore, we identify novel SVs affecting fruit acidity and proposed the diverged evolutionary trajectories of CmPH, a key regulator of melon fruit acidity, during domestication and selection of different populations. These results will offer valuable resources for genomic studies and genetic improvement in melon.

Melatonin enhances resistance to Botryosphaeria dothidea in pear by promoting jasmonic acid and phlorizin biosynthesis

Ring rot, caused by Botryosphaeria dothidea, is an important fungal disease of pear fruit during postharvest storage. Melatonin, as a plant growth regulator, plays an important role in enhancing the stress resistance of pear fruits. It enhances the resistance of pear fruits to ring rot by enhancing their antioxidant capacity. However, the underlying mechanism remains unclear. In this study, we examined the effect of melatonin on the growth of B. dothidea. Results showed that melatonin did not limit the growth of B. dothidea during in vitro culture. However, metabolomics and transcriptomics analyses of ‘Whangkeumbae’ pear (Pyrus pyrifolia) revealed that melatonin increased the activity of antioxidant enzymes, including peroxidase (POD), superoxide dismutase (SOD), and polyphenol oxidase (PPO), in the fruit and activated the phenylpropanoid metabolic pathway to improve fruit resistance. Furthermore, melatonin treatment significantly increased the contents of jasmonic acid and phlorizin in pear fruit, both of which could improve disease resistance. Jasmonic acid regulates melatonin synthesis and can also promote phlorizin synthesis, ultimately improving the resistance of pear fruit to ring rot. In summary, the interaction between melatonin and jasmonic acid and phlorizin enhances the antioxidant defense response and phenylpropanoid metabolism pathway of pear fruit, thereby enhancing the resistance of pear fruit to ring rot disease. Our results provide new insights into the application of melatonin in the resistance to pear fruit ring rot.

An insertion in the promoter of a malate dehydrogenase gene regulates malic acid content in apple fruit.

Malic acid is an important flavor determinant in apple (Malus × domestica Borkh.) fruit. One known variation controlling malic acid is the A/G single nucleotide polymorphism in an aluminum-activated malate transporter gene (MdMa1). Nevertheless, there are still differences in malic acid content in apple varieties with the same Ma1 genotype (Ma1/Ma1 homozygous), such as 'Honeycrisp' (high malic acid content) and 'Qinguan' (low malic acid content), indicating that other loci may influence malic acid and fruit acidity. Here, the F1 (Filial 1) hybrid generation of 'Honeycrisp' × 'Qinguan' was used to analyze quantitative trait loci for malic acid content. A major locus (Ma7) was identified on chromosome 13. Within this locus, a malate dehydrogenase gene, MDH1 (MdMa7), was the best candidate for further study. Subcellular localization suggested that MdMa7 encodes a cytosolic protein. Overexpression and RNA interference of MdMa7 in apple fruit increased and decreased malic acid content, respectively. An insertion/deletion (indel) in the MdMa7 promoter was found to affect MdMa7 expression and malic acid content in both hybrids and other cultivated varieties. The insertion and deletion genotypes were designated as MA7 and ma7, respectively. The transcription factor MdbHLH74 was found to stimulate MdMa7 expression in the MA7 genotype but not in the ma7 genotype. Transient transformation of fruit showed that MdbHLH74 affected MdMa7 expression and malic acid content in 'Gala' (MA7/MA7) but not in 'Fuji' (ma7/ma7). Our results indicated that genetic variation in the MdMa7 (MDH1) promoter alters the binding ability of the transcription factor MdbHLH74, which alters MdMa7 (MDH1) transcription and the malic acid content in apple fruit, especially in Ma1/Ma1 homozygous accessions.

Exogenous Application of Melatonin on the Preservation of Physicochemical and Enzymatic Qualities of Pepper Fruit from Chilling Injury

This study investigates the impact of melatonin (MT) treatment at varying concentrations (0, 25, 50, 75, 100 µmol L−1) on the post-harvest quality and shelf life of long green pepper fruits stored under low temperature for 28 days. Every 4 days, pepper fruits were examined for the chilling injury (CI) index, weight loss (WL), respiration rates, firmness, electrolyte leakage (EL), reactive oxygen species (ROS), malondialdehyde (MDA) levels, non-enzymatic antioxidant (NEA) content, antioxidant (AO) enzyme activity (superoxide dismutase (SOD), catalase (CAT), and peroxidases (PODs)), and cellular degrading enzymes (polygalacturonase (PG), pectin methylesterase (PME), phospholipase D (PLD), and lipoxygenase (LOX)). MT-treated samples exhibited delayed and reduced CI stress compared to controls, with higher exogenous MT concentrations (>50 µmol L−1) offering significant (p < 0.05) CI reductions. During storage, WL was notably mitigated by MT treatment in the tested samples compared to control samples. This study also demonstrated that MT-treated pepper fruits effectively decelerated respiration rates and consequently preserved pepper firmness. A higher concentration of MT-treated pepper fruits demonstrated a significantly (p < 0.05) lowered level of ROS and MDA while maintaining membrane stability, as evidenced by reduced EL. MT treatment with increasing concentration increased the levels of glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AsA), dehydroascorbate (DHA), and total phenolic content (TPC) in the pepper fruits compared to control and thus significantly (p < 0.05) suppressed the ROS production (superoxide anion (O2•−) and hydrogen peroxide (H2O2) radicals) in the pepper fruits. Furthermore, AO enzymes such as SOD, CAT, and POD were also high in the pepper fruits that were treated with higher concentrations of MT (>50 µmol L−1). Additionally, the activities of cellular degrading enzymes (PG, PME, PLD, and LOX), which are linked to senescence and stress-induced physiological disorders, were also effectively regulated by MT-treated (>75 µmol L−1) pepper fruits. Overall, the application of MT at higher concentrations (>75 µmol L−1) demonstrated substantial benefits in preserving the quality and extending the shelf life of pepper fruits during cold storage.

Comparative evaluation of the biochemical composition of fruits Malus spp.

To determine and compare the content of biochemical compounds in fruits of nine cultivars of M. domestica Borkh. and ten of Malus spp. (given in the research materials), to select the most promising for use in further breeding and recommend for use in various directions, considering the biochemical complex of characters, taste, and marketable qualities of fruits. The dry matter content, a sum of sugars, titratable acids, tannins, and ascorbic acid was evaluated for two years according to generally accepted operating methods. The large-fruited apple cultivars were found to have values of dry matter (11.2-22.8%) and small-fruited (15.5-30.9%); the total amount of sugars in large-fruited cultivars varies from 6.7 to 10.9%, in small-fruited from 7.5 to 12.7%; the amount of ascorbic acid in fruits of M. domestica fruits averaged from 6.0 to 12.2 mg.100 g-1, in crabapple from 6.6 to 22.8 mg.100 g-1; titratable organic acids in fruits of large cultivars ranged from 0.74 to 1.67%, in small ones from 1.50 to 2.34%; tannins content was found in the range from 0.06 to 0.52% in high-fruited cultivars and from 0.29 to 2.61% in lower-fruited ones. Comparative evaluation of the biochemical composition of fruits between large-fruited and small-fruited species and cultivars of apple trees showed that representatives of Malus spp. are more promising for use in breeding and industrial purposes. The dynamics of the decrease of dry soluble substance's weight and the increase of ascorbic acid content in apple tree fruits were also noted.

Transcriptional factor MdESE3 controls fruit acidity by activating genes regulating malic acid content in apple.

Acidity is a key factor controlling fruit flavor and quality. In a previous study, combined transcriptome and methylation analyses identified a P3A-type ATPase from apple (Malus domestica), MdMa11, which regulates vacuolar pH when expressed in Nicotiana benthamiana leaves. In this study, the role of MdMa11 in controlling fruit acidity was verified in apple calli, fruits, and plantlets. In addition, we isolated an APETALA2 domain-containing transcription factor, designated MdESE3, based on yeast one-hybrid (Y1H) screening using the MdMa11 promoter as bait. A subcellular localization assay indicated that MdESE3 localized to the nucleus. Analyses of transgenic apple calli, fruits, and plantlets, as well as tomatoes, demonstrated that MdESE3 enhances fruit acidity and organic acid accumulation. Meanwhile, chromatin immunoprecipitation quantitative PCR, luciferase (LUC) transactivation assays, and GUS reporter assays indicated that MdESE3 could bind to the ethylene-responsive element (ERE; 5'-TTTAAAAT-3') upstream of the MdMa11 transcription start site, thereby activating its expression. Furthermore, MdtDT, MdDTC2, and MdMDH12 expression increased in apple fruits and plantlets overexpressing MdESE3 and decreased in apple fruits and plantlets where MdESE3 was silenced. The ERE was found in MdtDT and MdMDH12 promoters, but not in the MdDTC2 promoter. The Y1H, LUC transactivation assays, and GUS reporter assays indicated that MdESE3 could bind to the MdtDT and MdMDH12 promoters and activate their expression. Our findings provide valuable functional validation of MdESE3 and its role in the transcriptional regulation of MdMa11, MdtDT, and MdMDH12 and malic acid accumulation in apple.

Nutritional, Phytochemical and Antioxidant Characterizations of Wild Food and Medicinal Fruits Indigenous to Sudan: Sarcocephalus latifolius and Vitex doniana

ABSTRACT Sudan is a rich country in wild plants that play significant roles in securing food and medicine in rural areas, especially. This study explored Sarcocephalus latifolius (African peach) and Vitex doniana (black plum) for their fruits’ proximate composition, minerals, total soluble phenols, phenolic acids, total carotenoids, lutein, β–carotene, α–tocopherol, δ–tocopherol and total antioxidant capacity. African peach fruit and black plum pulp showed total soluble phenols amounting to 16.89 mg gallic acid equivalents (GAE)/g of Dry Weight (DW) and 7.56 mg GAE/g DW, respectively. The paramount phenolic acids were cinnamic acid (895 mg/kg DW) in African peach fruit and protocatechuic acid (1200 mg/kg DW) in black plum pulp. Total antioxidant capacities reached 268 µmoles trolox equivalents (TE)/g DW in African peach and 214 µmoles TE/g DW in black plum, when measured from hydrophilic extracts (HPE) using 2, 2-DiPhenyl-1-PicrylHydrazyl (DPPH) assay. The contents of total carotenoid were 47 mg/kg DW and 22.6 mg/kg DW, lutein reached 18.50 mg/kg DW and 15 mg/kg DW whereas β–carotene showed 0.31 mg/kg DW and 0.23 mg/kg DW in African peach and black plum, respectively. African peach showed α–tocopherol (167 mg/kg DW) whereas black plum showed δ–tocopherol (398 mg/kg DW). From this study, we concluded that African peach fruit and black plum pulp could be good sources of nutrition and antioxidants and have high potential for human health.

Boosting genome-wide association power and genomic prediction accuracy for date palm fruit traits with advanced statistics

The date palm is economically vital in the Middle East and North Africa, providing essential fibres, vitamins, and carbohydrates. Understanding the genetic architecture of its traits remains complex due to the tree's perennial nature and long generation times. This study aims to address these complexities by employing advanced genome-wide association (GWAS) and genomic prediction models using previously published data involving fruit acid content, sugar content, dimension, and colour traits. The multivariate GWAS model identified seven QTL, including five novel associations, that shed light on the genetic control of these traits. Furthermore, the research evaluates different genomic prediction models that considered genotype by environment and genotype by trait interactions. While colour- traits demonstrate strong predictive power, other traits display moderate accuracies across different models and scenarios aligned with the expectations when using small reference populations. When designing the cross-validation to predict new individuals, the accuracy of the best multi-trait model was significantly higher than all single-trait models for dimension traits, but not for the remaining traits, which showed similar performances. However, the cross-validation strategy that masked random phenotypic records (i.e., mimicking the unbalanced phenotypic records) showed significantly higher accuracy for all traits except acid contents. The findings underscore the importance of understanding genetic architecture for informed breeding strategies. The research emphasises the need for larger population sizes and multivariate models to enhance gene tagging power and predictive accuracy to advance date palm breeding programs. These findings support more targeted breeding in date palm, improving productivity and resilience to various environments.

Impact of exogenous melatonin foliar application on physiology and fruit quality of wine grapes (Vitis vinifera) under salt stress.

Soil salinisation is an important abiotic stress faced in grape cultivating, leading to weakened plant vigour and reduced fruit quality. Melatonin as a novel hormone has shown positive exogenous application value. Therefore, this study used wine grape (Vitis vinifera ) 'Pinot Noir' as a test material to investigate the changes of foliar spraying with different concentrations of melatonin on the physiology and fruit quality of wine grapes in a field under simulated salt stress (200mmolL-1 NaCl). The results showed that foliar spraying of melatonin significantly increased the intercellular CO2 concentration, maximum photochemical quantum yield of PSII, relative chlorophyll and ascorbic acid content of the leaves, as well as the single spike weight, 100-grain weight, transverse and longitudinal diameters, malic acid, α-amino nitrogen and ammonia content of fruits, and decreased the initial fluorescence value of leaves, ascorbate peroxidase activity, glutathione content, fruit transverse to longitudinal ratio and tartaric acid content of plants under salt stress. Results of the comprehensive evaluation of the affiliation function indicated that 100μmolL-1 melatonin treatment had the best effect on reducing salt stress in grapes. In summary, melatonin application could enhance the salt tolerance of grapes by improving the photosynthetic capacity of grape plants under salt stress and promoting fruit development and quality formation, and these results provide new insights into the involvement of melatonin in the improvement of salt tolerance in crop, as well as some theoretical basis for the development and industrialisation of stress-resistant cultivation techniques for wine grapes.

Chemical and Sensory Evaluation on Several Varieties of Salak (Salacca zalacca) Fruit from Indonesia

Salak (Salacca zalacca) is an indigenous plant of Indonesia. It is widely distributed in several areas such as Yogyakarta, Bali, Sumatra, and Maluku. Several varieties of salak have been developed as a part of the government’s plant-breeding program. However, a detailed characterization of the sensory properties has not been reported. This study aimed to evaluate the chemical characteristics and consumer acceptance from six different varieties, namely Pondoh Super, Pondoh Madu, Pondoh Gading, Sari Intan 48, Sari Intan 295, and Sari Intan 541. Chemical characteristic tests included moisture content, fruit acidity (pH), total soluble solids, reducing sugar concentration, and vitamin C. Sensory evaluation on acceptance attributes, such as peel and flesh color, texture, aroma, taste, and overall preference was carried out by 40 untrained panelists. The results revealed that the chemical and sensory characteristics was varied among 6 varieties. Sari Intan 48 had the highest moisture content and pH compared to other varieties. Salak Pondoh Super had the highest levels of reducing sugar and vitamin C. On the other hand, Sari Intan 295 had the highest total soluble solids content. Male, female, and young panelists preferred the taste of Sari Intan 295. There was no significant difference in the parameters of peel color, flesh color, texture, aroma, taste, and overall preference in the adult panelists group. The group of panelists over 51 years old preferred the taste of the Sari Intan 541. The occurrence of a sour taste significantly affected panelists acceptance of salak fruit.

Electrical Properties for Non-destructive Determination of Free Fatty Acid and Moisture Content in Oil Palm Fruit

FFA content is one of the essential qualities of oil palm fruit. FFA content exceeding 5% is considered unsuitable for human consumption. Commonly, FFA content is determined by chemical methods in the laboratory, but it is destructive, time-consuming, and costly. Several non-destructive methods have been investigated, but a maturity prediction approach has been primarily used with no direct relation to FFA content. Thus, there is a pressing need for a non-destructive framework to assess the FFA levels in the oil palm fruit directly. An attempt has been explored using a non-destructive palm fruit quality assessment that relied on electrical properties (impedance, admittance, resistance, and capacitance) in the frequency range from 50 Hz to 5 MHz was investigated to predict FFA and moisture content directly. Two statistical analyses were employed: stepwise multiple linear regressions (MLR) and artificial neural networks (ANN) to calibrate and validate electrical properties with FFA and moisture content. The best-performing models ANN showcased significant results: r= 0.96, R2=0.92, SEC at 0.86%, SEP at 0.97%, CV at 19.45%, consistency at 88.54, and RPD at 3.43 for FFA prediction, and r= 0.99, R2=0.98, SEC at 3.09 %, SEP at 3.46 %, CV at 5.44 %, consistency at 89.08 and RPD at 7.02 for predicting moisture content. In modeling oil palm quality determination, applying the ANN method significantly improved model performances, demonstrating its efficacy in predicting non-destructively both FFA levels based on admittance and moisture content based on impedance.