Search Results (20)

Odor-induced sweetness enhancement (OISE) is an effective approach to lower sugar intake. In this study, static and dynamic sensory evaluations, combined with molecular docking, were used to explore the mechanism underlying sweetness enhancement in fructose solutions induced by watermelon juice odor compounds. Sensory evaluation results showed that the seven volatile odor compounds (VOCs) (ethyl acetate, ethyl propionate, octanal, (E,E)-2,4-hexadienal, (E)-2-octenal, methyl heptenone, and geranyl acetone) from watermelon juice could significantly increase the sweetness intensity of a 2.5% fructose solution, and the potency of OISE was significantly enhanced within 10 s. (E,E)-2,4-hexadienal, ethyl propionate, and methylheptenone showed the most significant OISE effects, which aligned with the sensory preference results. Further, molecular docking was used to explore the interactions between VOCs, fructose, and sweet receptors. The results showed that T1R2 was the main receptor for binding fructose and VOCs, and the interaction forces were primarily hydrogen bonds and hydrophobic interactions. In the presence of VOCs, the amino acid residues that formed hydrogen bonds with fructose were highly repetitive, with the main difference being the bond length, indicating the important role of flavor–sweetener receptor interactions in lowering fructose content and enhancing sweetness perception. Thus, this study provides a scientific basis for developing sugar-reduction technology based on aroma, in addition to enhancing sweetness. Full article

The present study aimed to investigate the occurrence of eight potentially toxic elements (PTEs) in selected varieties of watermelon (Citrullus lanatus var. Arka Shyama and Crimson Sweet) and muskmelon (Cucumis melo var. Cantaloupe and Kajri) grown near riverbanks in the Yamuna and Ganga River basins of Northern India. For this purpose, samples of melon fruits were collected from ten sampling sites from May to June 2024 and analyzed using ICP-OES. The results showed that the levels of PTEs varied significantly across the sampling sites, with muskmelons exhibiting slightly higher concentrations compared to watermelons. Specifically, the concentration (mg/kg dry weight) ranges for the watermelon varieties were Cd (0.05–0.20), Cr (0.40–1.10), Cu (1.50–4.90), Pb (0.01–0.11), As (0.01–0.08), Fe (80.00–120.00), Mn (9.00–15.80), and Zn (5.00–18.00). For muskmelons, the ranges were Cd (0.05–0.23), Cr (0.40–1.00), Cu (2.40–4.80), Pb (0.01–0.08), As (0.02–0.08), Fe (80.00–120.00 g), Mn (9.00–15.00), and Zn (8.00–18.00). In particular, the variability coefficients (CV%) indicated differential contamination in Crimson Sweet. On the other hand, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) tools facilitated the identification of sites of significant contamination and their respective interactions. The health risk studies using the health risk index (HRI), dietary intake modeling (DIM), and the target hazard quotient (THQ) also revealed no significant health risk of eight PTEs in melon fruits. Therefore, this study provides valuable insights into the biomonitoring of PTE contamination in widely consumed summer fruits of Northern India and the subsequent health risk assessment. Full article

Watermelons are in high demand for their juicy texture and sweetness, which is linked to their soluble solids content (SSC). Traditionally, watermelons have been sold as whole fruits. However, the decline in the mean size of households and the very large size of the fruits, together with high prices, mainly at the beginning of the season, mean that supermarkets now sell them as half fruits. For consumers, it is important to know in advance that the fruits that they are purchasing are of a high quality, based not only on external flesh colour but also on sweetness. Near-infrared spectroscopy (NIRS) and Raman spectroscopy were used for the in situ determination of SSC in half watermelons while simulating supermarket conditions. A handheld linear variable filter (LVF) device and an all-in-one (AIO) Process Raman analyser were used for the NIRS and Raman analysis, respectively. The excellent results obtained—including residual predictive deviation for prediction (RPD_p) values of 3.06 and 2.90 for NIRS and Raman, respectively—showed the viability of NIRS and Raman spectroscopies for the prediction of sweetness in half watermelons. Full article

Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera^®, Gavina^®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators. Full article

Growing conditions and seasonal fluctuations are critical factors affecting fruit and vegetable nutritional quality. The effects of two partially overlapping cropping seasons, early (ECS; January–May) and full (FCS; March–July), on the main carpometric traits and bioactive components of different watermelon fruits were investigated in the open field. Four watermelon genotypes, comprising of three commercial cultivars ‘Crimson Sweet’, ‘Dumara’, ‘Giza’, and the novel hybrid ‘P503 F1’, were compared. The carpometric traits varied significantly between genotypes. Soluble solids and yield were higher under FCS than ECS. The variation affecting colour indexes between the two growing seasons exhibited a genotype-dependent trend. The antioxidant components and radical scavenging activity of watermelon fruits were also significantly affected by differences in received solar energy and temperature fluctuations during the trial period. The average citrulline, total phenolics and flavonoid contents were 93%, 71% and 40% higher in FCS than in ECS. A genotype-dependent variation trend was also observed for lycopene and total vitamin C between cropping seasons. The hydrophilic and lipophilic radical scavenging activities of the pulp of ripe watermelon fruits of the different genotypes investigated varied between 243.16 and 425.31 µmol Trolox Equivalent (TE) of 100 g⁻¹ of fresh weight (fw) and from 232.71 to 341.67 µmol TE of 100 g⁻¹ fw in FCS and ECS, respectively. Our results, although preliminary, show that the functional quality of watermelon fruits is drastically altered depending on the environmental conditions that characterize the ECS and LCS. Full article

Vegetables are considered high value crops based on their growing areas and productivity, even if they are affected by a variety of insect pests throughout the whole growing season. Leaf miner is an immature of an insect that lives inside and consumes the leaf tissues of vegetable plants. Adult females of leaf miner puncture the leaf with their ovipositor, forming tube pattern, and feed on the punctured parts. Host plants survey of leaf miner in Multan (Pakistan) area was conducted. Twenty host plants were found in 2017, whereas twenty-four host plants were found infested with Liriomyza spp. (Diptera) in 2022 i.e., watermelon (24% infestation), long melon (75%), pumpkin (71%), round gourd (67%), snake melon (70%), bitter gourd (50%), long gourd (89%), bottle gourd (93%), pointed gourd (80%), snap gourd (86%), ridge gourd (83%), cucumber (98%), mung bean (98%), eggplant (60%), Petunia alba (88%), Zinnia elegies (30%), cotton (10%), okra (5%), berseem (7%), tomato (89%), Pea (52%) and Canola (28%). No infestation of leaf miners was observed on potato, chilies, and sweet potatoes. Color attraction results in 2017 and 2022 showed that there was maximum attraction of tomato leaf miner towards yellow sticky cards as compared to blue sticky cards. Varietal preference of tomato crop showed that Baby red variety was the most preferred by leaf miner (Liriomyza spp.), and comparatively Sehar was the least preferred variety. Field efficacy of four different insecticides against leaf miner were also tested. Insecticidal effects attributed as percent reduction of leaf miner infestation that showed the highest reduction values were observed after 7 DOA for Spinetoram (76.98%), whereas Bifenthrin (57%). Deltaphos (43 %) was the least toxic insecticide against Liriomyza spp. Integrated approaches are recommended to manage vegetable leaf miner like application of yellow sticky traps, discouraging preferred host plants, application of insecticides with novel modes of actions like spintoram and spinosad for effective management. Full article

In this study, the trend of VOCs of dietary fiber samples, coming from three different watermelon cultivars Citrullus lanatus L. (variety Gavina^®®, Crimson Sweet, and Asahi Miyako) was investigated. This foodstuff, obtained as a by-product of residual agri-food production, has gained increasing attention because of its many bioactive components and high dietary fiber content. The result is a fibrous material for specific applications in food manufacturing, such as corrector for some functional and technological properties. In this study, a method based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS) was used to characterize the aromatic profiles of the dried raw materials. Therefore, the VOCs of the samples of the three cultivars were investigated. Experimental results have shown that watermelon fibers generate VOCs, which can be grouped into six common classes of analytes. The different distributions of the identified compounds made it possible to effectively differentiate the three cultivars studied based on their peculiar aroma profiles. In particular, Gavina^®® fiber is distinguished by the high content of terpenes, Asahi Miyako by the presence of aldehydes generated as fatty acid metabolites, and Crimson Sweet by the higher content of acetyl esters. Full article

Sweetness or sugar content, represented by soluble solids contents (SSC), is a vital quality trait in watermelon breeding which can be assessed by the refractive index method. However, sampling watermelon juice out of the pulp is a process that is both labor-intensive and error-prone. In this study, we developed an automatic SSC measurement system for watermelon breeding to improve efficiency and decrease costs. First, we built an automatic cutting system to cut watermelons into precise halves, in which a laser rangefinder is used to measure the distance from the upper surface of the watermelon to itself, and thus, the diameter is estimated. The experiments showed a high correlation between the estimated diameters and the ground truths, with and . Then, we built an automatic Brix measurement system to obtain the Brix data from a central point on the watermelon’s section, where an image analysis procedure is applied to locate the testing point. This is then transformed to the camera coordination system, and a refractometer is driven by a 3-axis robotic arm to reach the testing point. Brix measurement experiments were conducted using three vertical gaps and four lateral gaps between the probe of the refractometer and the pulp. The result showed that the best parameters were a vertical gap of 4 mm and a lateral gap of 2 mm. The average accuracy reached 98.74%, which indicates that this study has the potential to support watermelon breeding research. Full article

Two rootstock hybrids of sweet melons and watermelons (“Kickstart” and “Carnivor” Cucurbita moschata × Cucurbita maxima) grafted onto two watermelon cultivars (scions), “Honeygoal” and “Honeyval”, were examined in this study to determine whether functional compounds, antioxidant properties, and volatile compounds were retained after five days of cold storage at 5 °C and 85% RH following harvest. An interaction exists between cultivars, rootstocks, and storage for total phenolic content, ascorbic acid, chlorophyll content, antioxidant activities, and volatile compounds. Generally, all functional compounds and antioxidant properties decreased during storage; however, “Honeygoal/Carnivor” in cold storage for 7 days retained the total phenols, ascorbic acid, chlorophyl contents, DPPH (15.47 IC₅₀ mg/mL), ABTS (1.06 IC₅₀ mg/mL) scavenging activities, and antioxidant power (IC₅₀ mg/mL) higher than ungrafted, “Honeyval” or “Honeygoal/Kickstart”, “Honeyval/Carnivor” or “Honeyval/Kickstart” melons. The heat map showed a higher abundance of volatile compounds in “Honeygoal/Carnivor” and “Honeyval/Carnivor” melons stored for 7 and 14 days while “Honeygoal/Kickstart” or “Honeyval/Kickstart” requires 14 days of storage. “Honeygoal/Carnivor” and “Honeyval/Carnivor” melons stored for up to 7 days in cold storage were preferred by panelists. Hence, grafting “Honeygoal” melons onto “Carnivor” rootstocks helped to improve the functional compounds, antioxidant properties, and volatiles during storage for 7 days after harvest. Full article

The single cell protein (SCP) technique has become a popular technology in recent days, which addresses two major issues: increasing world protein deficiency with increasing world population and the generation of substantial industrial wastes with an increased production rate. Global fruit production has increased over the decades. The non-edible parts of fruits are discarded as wastes into the environment, which may result in severe environmental issues. These fruit wastes are rich in fermentable sugars and other essential nutrients, which can be effectively utilized by microorganisms as an energy source to produce microbial protein. Taking this into consideration, this review explores the use of fruit wastes as a substrate for SCP production. Many studies reported that the wastes from various fruits such as orange, sweet orange, mango, banana, pomegranate, pineapple, grapes, watermelon, papaya, and many others are potential substrates for SCP production. These SCPs can be used as a protein supplement in human foods or animal feeds. This paper discusses various aspects in regard to the potential of fruit wastes as a substrate for SCP production. Full article

Understanding the genetic basis of a crop’s qualitative and quantitative traits is vital to designing market preferred varieties. The aim of this review is to present a retrospective genetic analysis of qualitative and quantitative phenotypic traits in sweet watermelon as a guide for trait integration and the development of novel varieties with yield potential and desirable horticultural attributes. The first section outlines genes conditioning the inheritance of plant architecture (e.g., leaf attributes and plant architecture), floral characters (flowering rate, sex expression, and male sterility), fruit traits (shape, colour, rind colour and stripe patterns and flesh colour) and seed morphology (seed length, width, size and coat colour). In the second section, developments in molecular markers and quantitative trait loci (QTL) to aid marker-assisted breeding are discussed. Further, the review highlights the clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) gene-editing technology and its scope in gene manipulations and new variety development. The information presented in this review is useful for optimised and demand-led breeding to develop new varieties to serve growers, consumers and the sweet watermelon industry. Full article

Cucurbits in Southeastern USA have experienced a drastic decline in production over the years due to the effect of economically important viruses, mainly those transmitted by the sweet potato whitefly (Bemisia tabaci Gennadius). In cucurbits, these viruses can be found as a single or mixed infection, thereby causing significant yield loss. During the spring of 2021, surveys were conducted to evaluate the incidence and distribution of viruses infecting cantaloupe (n = 80) and watermelon (n = 245) in Georgia. Symptomatic foliar tissues were collected from six counties and sRNA libraries were constructed from seven symptomatic samples. High throughput sequencing (HTS) analysis revealed the presence of three different new RNA viruses in Georgia: cucumis melo endornavirus (CmEV), cucumis melo amalgavirus (CmAV1), and cucumis melo cryptic virus (CmCV). Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the presence of CmEV and CmAV1 in 25% and 43% of the total samples tested, respectively. CmCV was not detected using RT-PCR. Watermelon crinkle leaf-associated virus 1 (WCLaV-1), recently reported in GA, was detected in 28% of the samples tested. Furthermore, RT-PCR and PCR analysis of 43 symptomatic leaf tissues collected from the fall-grown watermelon in 2019 revealed the presence of cucurbit chlorotic yellows virus (CCYV), cucurbit yellow stunting disorder virus (CYSDV), and cucurbit leaf crumple virus (CuLCrV) at 73%, 2%, and 81%, respectively. This finding broadens our knowledge of the prevalence of viruses in melons in the fall and spring, as well as the geographical expansion of the WCLaV-1 in GA, USA. Full article

In light of the great technological progress in non-destructive quality detection methods, sweetness is no longer the essential parameter in evaluating watermelon quality. There is an aspiration to determine physicochemical quality characteristics to enable us to select the best cultivars, agricultural practices, and harvest dates. In the present work, three different watermelon cultivars (Lady, Galander, and Style) were harvested at three consecutive harvest times. Two pieces were taken from each watermelon sample, one from the middle (part A) and the other from the ends (part B), to track the intensity of quality parameters inside the watermelon. Parts A and B were subjected to Vis/NIR spectroradiometer (475:1075 nm), near-infrared spectroscopy (NIRS) (950:1650 nm), and high-performance liquid chromatography to assess the physicochemical quality. Calibration and prediction models were conducted using partial least squares regressions (PLS). The results indicated that the harvesting time significantly influenced the color and chemical parameters. Quality parameters concentrations markedly degraded towards late harvest. The highest concentrations of quality parameters were sighted for the middle zone (part A), especially in the Galander cultivar. Spectroradiometer achieved the best coefficient of prediction (R²_P) ≃ 0.88 and 0.81 attached with the lowest value of the standard error of prediction (SEP) ≃ 0.03 and 1.06 for chroma (C*) and yellowness index (YI). However, the findings showed the superiority of the NIRS compared to the Vis-NIR method. The highest R²_P was achieved by values 0.92, 0.91, 0.90, 0.89, 0.85, and 0.85 for lycopene, total carotenoids, vitamin C, β-carotene, γ-content, and TSS, respectively. It could be concluded that the NIRS has the ability to monitor the maturity development and determine the harvest dates practically and reliably. Full article

The discovery of several waterlogged plant remains in a Middle Ages context (1330–1360 AD) in Sassari (NS, Sardinia, Italy) enabled the characterisation of archaeological plum fruit stones and watermelon and grape seeds through computer image analysis. Digital seed/endocarp images were acquired by a flatbed scanner and processed and analysed by applying computerised image analysis techniques. The morphometric data were statistically elaborated using stepwise linear discriminant analysis (LDA), allowing comparisons among archaeological remains, wild populations and autochthonous cultivars. Archaeological samples of plum were compared with 21 autochthonous cultivars of Prunus domestica from Sardinia, while archaeological watermelon seeds were compared with 36 seed lots of Citrullus from Europe, Africa and Asia. Moreover, archaeological grape seeds were compared with 51 autochthonous traditional cultivars of Vitis vinifera subsp. vinifera from Sardinia, 16 cultivars from Tuscany, six cultivars from Liguria, and eight cultivars from Catalonia (Spain). Archaeological plum remains showed morphological affinity with five cultivars of Sardinia. Seed features of the archaeological watermelon remains demonstrated affiliation with a proper sweet dessert watermelon, Citrullus lanatus, and similarity with some Sardinian cultivars. Regarding the archaeological remains of grape, morphometric comparisons showed a high similarity with autochthonous cultivars from Catalonia and Liguria. This study provides new information about ancient fruit cultivated and consumed during the Middle Ages in Sardinia. Full article

Watermelon (Citrullus lanatus) consists of high moisture content and is favoured for its juice products. The popular fruit has a tempting taste, sweet aroma and attractive flesh colour. It is enriched with phytochemicals and antioxidant properties that are beneficial to human health. Due to convenience, the majority of individuals are likely to consume watermelon juice. However, little is known about the fruit juice storage and temperatures that may affect its beneficial properties. This study investigated the effect of storage temperature at room temperature, refrigerator cold, refrigerator freeze and freeze-dried, and analyzed the juice physico-chemicals (weight loss, pH, ash, moisture, total soluble solid, browning and turbidity), phytochemicals (total phenolic, total flavonoid, lycopene and β-carotene) and antioxidant scavenging activities during 9 days of storage. The results showed that watermelon juice was affected by storage temperatures and conditions with significant changes in physico-chemical appearance and decrease in total phytochemical content, thus consequently affecting their antioxidant activities during 9 days of storage. Although fresh watermelon juice can be consumed for its high nutritional values, freeze-drying is the preferable technique to retain its benefits and to delay juice degradation. Full article