Search

Muskmelon (Cucumis melo L.) is a popular summer fruit consumed all over the world due to the combination of refreshingly sweet taste, pleasant flavour and nutritional value. Melon fruit is characterized by germplasm variability with superior quality. This study aimed to evaluate 5 promising local muskmelon cultivars (Maazoun, Galaoui, Stambouli, Trabelsi, Asli) for some physicochemical characteristics, the content of different bioactive compounds and the antioxidant activity. The experiments were conducted for two consecutive years 2018 and 2019 at the support station of the inter-professional vegetable group positioned in the North East of Tunisia. Significant differences were observed across the melon cultivars (P

Landraces are considered a crucial component of biodiversity conservation, serving as a reservoir of genetic diversity. Consequently, the collection, cultivation, and detailed characterization of such landraces constitute an inherent aspect of the world's natural resource heritage. This effort holds promise for the development of elite varieties capable of thriving amidst continuous global climate fluctuations. In this context, we conducted a comprehensive assessment of the main agronomic attributes, physico-chemical properties, and functional quality traits of the major hot pepper landraces adapted to diverse climatic conditions in Tunisia. These landraces include 'Dhirat', 'Semmane', 'Beldi', 'Nabeul', 'Jerid', 'Mahdia', 'Cayenne', 'Kairouan', and 'Baklouti'. Most of the pepper landraces exhibited satisfactory yields, ranging from 1163.25 to 1841.67 g plant−1 in 'Jerid' and 'Kairouan', respectively, indicating robust productivity, especially under prevailing climatic changes and high temperatures during both growing cycles. The levels of antioxidants comprising capsaicinoids, carotenoids, phenolics, and tocopherols, as well as radical scavenging activity, emerged as key discriminating factors among pungent pepper landraces. Irrespective of genotype, capsaicin and dihydrocapsaicin constituted the major capsaicinoids, accounting for 44–91% of the total capsaicinoids content. Total capsaicinoids ranged from 1.81 µg g−1 fw to 193.71 µg g−1 fw, with 'Baklouti' and 'Jerid' identified as the most pungent landraces. Total carotenoids ranged from 45.94 µg g−1 fw to 174.52 µg g−1 fw, with 'Semmane' and 'Jerid' exhibiting the highest levels. Considerable variation was observed in β-carotene content, spanning from 3% to 24% of the total carotenoids. α-Tocopherol content ranged from 19.03 µg g−1 fw in 'Kairouan' to 30.93 µg g−1 fw in 'Beldi', exerting a notable influence on the overall tocopherol content. Conversely, the β- and γ-tocopherol isomers were detected at very low concentrations. The total vitamin C content ranged from 132 mg 100g−1 fw in 'Mahdia' to 200 mg 100 g−1 fw in 'Nabeul', indicating relatively low genetic variability. However, large variability was detected in total phenolics content, ranging from 168.58 mg GAE kg−1 fw in 'Beldi' to 302.98 mg GAE kg−1 fw in 'Cayenne'. Landraces such as 'Dhirat', 'Nabeul', 'Semmane', 'Kairouan', 'Cayenne', and 'Mahdia' appear suitable for both fresh consumption and processing, owing to their favorable average fruit weight, soluble solids content, and bioactive content. Among the pepper landraces tested, 'Cayenne' achieved the highest value of radical scavenging activity in both hydrophilic and lipophilic fractions (RSAHF and RSALF), with variations ranging from 59% to 120% for RSAHF and from 4% to 63% for RSALF. This study aims to preserve and enhance the value of local genetic resources and contribute to identify desirable traits for incorporation into breeding programs to develop high-quality, high-yielding landraces and elite lines. [ABSTRACT FROM AUTHOR]

This research work's central focus is synthesizing a novel hybrid compound, formulated as [C6H9N2]2Sb2Cl8. This compound was prepared using the slow evaporation method and confirmed through single-crystal X-ray diffraction at 293 K. It crystallizes in the triclinic system with the centrosymmetric space group P 1 ¯ symmetry, and its unit cell (Z = 2). The intermolecular interactions have been studied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the Cl–H contacts contribute the most to the surface area (63.6%). Computational studies that include geometry optimization and harmonic vibrational frequencies were performed using B3LYP method with GENECP set. Acceptable consistency was observed between calculated and experimental results. The assignment of wavenumbers was based on potential energy distribution (PED) using Vibrational Energy Distribution Analysis (VEDA) software. The optical band gap determined by UV–Visible spectroscopy is 3.48 eV for a direct allowed transition. Impedance spectroscopy was performed over a temperature range of 313 K to 413 K and a frequency range of 0.1 Hz to 1 MHz. The Nyquist plots indicated the presence of grain contributions. The conductivity study revealed that the synthesized material exhibits semiconductor behavior. A thermally activated conduction process was identified through the study of alternating conductivity, with a calculated activation energy of 1.104 eV. Additionally, the title compound exhibits a negative temperature coefficient of resistivity (TCR) with value of − 13%, suggesting the suitability of the sample for IR radiation detection applications. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is a staple food widely consumed in Tunisia and represents a source of various secondary metabolites with human health benefits. However, cold storage of potato tuber affects their bioactive properties and functional quality. Despite the importance of this fact, few studies have examined the effects of extended cold storage on potato tubers quality. Therefore, the objective of the present work was to evaluate the effect of cold storage on the main quality traits of different potato genotypes grown in Tunisia. This investigation focused on four cultivated potato varieties including three commercial (Selena, Elbeidha, and Naima) and a selected clone CL27 grown under late cropping season conditions with planting at the beginning of autumn and a winter tuberization. The tubers from this trial were stored for 90 days at 8°C. The results obtained showed that quality traits of potato tubers were strongly influenced by storage at 8°C throughout 90 days. Additionally, disregarding the genotype, total carotenoids, phenolics, and flavonoids contents increased significantly following 90 days storage at 8°C. However, genotypic differences underlying the antioxidant activity in both hydrophilic and lipophilic fractions were detected suggesting their sensibility to cold storage. This study might be useful for breeders working on potato genotypes suitable for extended storage duration and for growers storing their material for extended period under low temperature. Core Ideas: The effect of storage varies according to the considered genotype.Stored tubers at 8°C for 90 days exhibited higher nutritional quality with respect to fresh samples.Appropriate storage can contribute to maintain high‐quality potato tubers. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is a staple food widely consumed in Tunisia and a source of nutrients beneficial for human health. The tubers are, indeed, important source of vitamins, minerals, and bioactive compounds, including carotenoids, polyphenols, and flavonoids. However, data regarding the functional quality of potato varieties grown and consumed in Tunisia are very scarce. For this reason, two field trials were conducted to focus on the effect of the growing season on the functional quality of four potato genotypes (Selena, El Beidha, Naima, and CL07F172.5): a first autumnal trial in Teboulba, Monastir (September 2015–February 2016), which is the late cropping season (LCS) and a second summer cropping season (SCS) in El ksour, El Kef region at an altitude > 1000 m (July 2015–October 2015). Total carotenoids, total phenolics, and flavonoids contents, as well as the hydrophilic radical scavenging activity and lipophilic radical scavenging activity (LRSA) were determined. The obtained results confirmed the importance of potato tubers as a source of bioactive compounds. All quality traits varied significantly among varieties and cropping seasons. Tubers grown under colder weather conditions (LCS: minimum and maximum averages temperatures and relative humidity (RH) ranging between 14.25 and 22.55°C and 25.46% and 83.07%, respectively) accumulated the highest total vitamin C content and exhibited the highest LRSA values. However, temperature and warmer growing conditions (SCS: minimum and maximum averages temperatures and RH ranging between 19.74 and 34.22°C and 35.46% and 87.51%, respectively) probably enhanced the synthesis and accumulation of total carotenoids, total phenolics, and total flavonoids, associated with higher LRSA values. Core Ideas: The development of a new summer cropping season in Tunisia is examined.The production and quality traits are similar to other potato cropping season.Highland potato production is promising and contributes to fill the existing gap. [ABSTRACT FROM AUTHOR]

Tomato landraces have progressively faded into obscurity, making way for new hybrids and elite tomato cultivars. This study presents a comprehensive evaluation of the agronomic attributes, physicochemical properties, and functional traits across seven cultivars, comprising two high-pigment varieties, 'HLT−F81' and 'HLT−F82', as well as five underutilized ancient-tomato genotypes considered as landraces. Most of the studied genotypes exhibited satisfactory horticultural and processing traits. The average fruit weight ranged from 73.3 g in 'Rimone' to 91.83 g in 'HLT−F81', while the soluble solids content ranged from 4.66 °Brix in 'Justar' to 6.08 °Brix in 'HLT−F81'. The functional quality and the content of most antioxidants, as well as the antioxidant activity in both hydrophilic and lipophilic fractions, proved to be the most discriminating parameters among the tomato genotypes. The content of β−carotene and lycopene spanned from 2.94 mg kg−1 fw in 'Rio Grande' to 13.94 mg kg−1 fw in 'HLT−F82' and 227.8 mg kg−1 fw in 'HLT−F81', yielding large variations compared to 'Rio Grande'. The total phenolic content ranged from 139.83 mg GAE kg−1 fw in 'Rimone' to 352.41 mg GAE kg−1 fw in 'HLT-F81', while the flavonoid content varied from 136.16 mg RE kg−1 fw in 'Justar' to 311.23 mg RE kg−1 fw in 'HLT-F82'. The presence of tocopherol isomers was genotype-dependent, with a higher content in lines carrying the high-pigment mutations. Among the tested tomato genotypes, the high-pigment tomato line 'HLT−F81' achieved the highest hydrophilic and lipophilic antioxidant activity values. This study primarily focused on the recovery and valorization of tomato genetic resources and landraces. It also aimed to identify desirable horticultural (yield, low-input, and low-water demand), processing (°Brix and titratable acidity), and quality (rich antioxidant berries) traits for introgression into new tomato cultivars better suited to the evolving climate conditions of the near future. [ABSTRACT FROM AUTHOR]

This study investigates the antioxidant components (total carotenoids, lycopene, β-carotene, total phenols, flavonoids, ascorbic acid and total vitamin C) as well as the hydrophilic and lipophilic antioxidant activities (HAA and LAA) of tomato genotypes consisting of one ordinary cultivar Rio Grande and the two high-lycopene breeding lines HLT-F71 and HLT-F72. The correlation of nutritional value to L∗, a∗, b∗ colour indexes and a∗/b∗ ratio was also investigated in whole and fresh cut tomato fruits. Except for β-carotene content, significant differences were found among cultivars for antioxidants. The berries of both HLT-lines recorded higher antioxidant contents, HAA and LAA (TEAC and FRAP assays) than Rio Grande. Under controlled conditions, HLT-F72 reached the highest levels of total carotenoids (165.5 mg β-ca Eq per kg fw), lycopene (150.1 mg per kg fw) and total phenolics (549.7 mg GAE per kg fw). However, HLT-F72 exhibited the highest levels of ascorbic acid (193.3 mg per kg fw), total vitamin C (271.6 mg per kg fw) and flavonoids (450.5 mg RE per kg fw). Line HLT-F71 showed the highest HAA (148.0 µM Trolox per 100 g fw and 4.2 mM FRAP per g fw) and LAA values (258.5 µM Trolox per 100 g fw and 3.2 mM FRAP per g fw respectively). Colour readings in red ripe fresh cut tomato berries particularly a∗, b∗ and the ratio a∗/b∗ could represent an indicator not only for lycopene but also for other phytochemicals and resulting antioxidant activities. HLT-Lines may serve as a starting point for the development of semi-determinate growth habit tomato cultivars with higher functional quality.

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. [ABSTRACT FROM AUTHOR]

Sensorless control of a permanent magnetsynchronous motor (PMSM) at low speed remains a challenging task. In this paper, a sensorless vector control of PMSM using a new structure of a sliding mode observer (SMO) is proposed. To remove the mechanical sensors, a full‐order (FO‐SMO) is built to estimate the rotor position and speed of PMSM drives. The FO‐SMO, which replaces a sign function by a sigmoid function, can reduce the chattering phenomenon. In order to overcome time delay, we cancel the low pass filter. This sensorless speed control shows great sensitivity to stator resistance and system noise. To improve the robustness of sensorless vector control, a full‐order SMO technique has been used for stator resistance estimation. A novel stator resistance estimator is incorporated into the sensorless drive to compensate for the effects of stator resistance variation. The validity of the proposed FO‐SMO with a 1.1 kw low‐speed PMSM sensorless vector control is demonstrated by experiments. In this paper, experimental results for FO‐SMO, back‐EMF SMO and MRAS techniques were obtained with fixed point DSP‐based (TMS320F240). [ABSTRACT FROM AUTHOR]

Abstract: Changes in bioactive compounds and antioxidant activities of three commercial selections (Crimson sweet, Dumara and Giza) and two new selections (P503 and P403) of watermelon cultivars were investigated at four different fruit ripening stages (white, white-pink, pink and red-ripe). Lipophilic and hydrophilic antioxidant activities (LAA and HAA, respectively) were determined, and their correlations with total vitamin C, phenol, flavonoid, lycopene and β-carotene contents were studied. Ripening stage significantly influenced lycopene and β-carotene contents, as well as the LAA of all investigated watermelon cultivars. Good correlations between LAA and lycopene and β-carotene contents were found using the TEAC assay. At the red-ripe stage of ripeness, P503 cultivar showed the highest amount of lycopene (64.5mgkg−1 fw), whereas Dumara cultivar showed the highest level of β-carotene (2.1mgkg−1 fw). Giza cultivar scored first for total phenol (260.1mgGAEkg−1 fw), flavonoid (260.0mgREkg−1 fw) and total vitamin C (204.0mgkg−1 fw) contents. Although, the HAA of the studied watermelon cultivars was significantly influenced by the ripening stages, it only correlated to the amount of total phenols and flavonoids. These data confirm the important role played by genetic background and ripening stage in determining antioxidant potential of watermelon fruits. They also give valuable insights into the synthesis and accumulation of bioactive compounds in such fruits, and furthermore move us closer to identifying the harvesting period with the highest antioxidant potential. [Copyright &y& Elsevier]