Search Results (70)

Hazelnut (Corylus avellana L.) is a significant global agricultural product due to its high economic and nutritional worth. The traditional methods used to measure the hazelnut kernel percentage for quality assessment are often time-consuming, expensive, and prone to human errors. Inaccurate measurements can adversely impact the market value, shelf life, and industrial applications of hazelnuts. This research introduces a novel system for calculating hazelnut kernel percentage utilizing a non-destructive X-ray imaging technique along with deep learning methods to assess hazelnut quality more efficiently and reliably. An image dataset of hazelnut kernels has been developed using X-ray technology, and defective areas are identified employing YOLOv7 architecture. Additionally, a novel bounding box regression technique called DCIoU and an algorithm for Neighborhood Relationship have been introduced to enhance object detection capabilities and to improve the selection of the target box with greater precision, respectively. The performance of these proposed methods has been evaluated using both the created hazelnut dataset and the COCO-128 dataset. The results indicate that the system can serve as a valuable tool for measuring hazelnut kernel percentages by accurately identifying defects in hazelnuts. Full article

The purpose of this study was to evaluate the energy and environmental potential of waste biomass in the form of hazelnut shells from selected Turkish varieties of Corylus avellana L. Eight commercial varieties (Çakıldak, Foşa, İnce Kara, Kalın Kara, Palaz, Tombul, Yassı Badem and Yuvarlak Badem) grown in different regions of the Black Sea coast of Turkey were analyzed. The scope of this study included whole nut and shell weight determination, technical and elemental analysis, higher heating value (HHV) and lower net heating value (LHV), as well as emission factors (CO, CO₂, NO_x, SO₂, dust) and flue gas composition based on stoichiometric calculations. The results showed a significant effect of varietal characteristics on all analyzed parameters. The share of shell in the total weight of the nut ranged from 43.5% (Tombul) to 55.3% (İnce Kara). HHV values ranged from 18.37 to 19.20 MJ·kg⁻¹, and LHV from 17.05 to 17.90 MJ·kg⁻¹. The İnce Kara and Yassı Badem varieties showed the most favorable energy properties. Elemental analysis confirmed a low nitrogen and sulfur content, which translated into low NO_x and SO₂ emissions. NO_x emissions were lowest for the Tombul variety (1.43 kg·Mg⁻¹), and SO₂ emissions were close to zero in each variety. The results confirm that Turkish hazelnut shells are a valuable energy resource and can be used as solid fuel or supplementary biomass. In particular, the İnce Kara variety was identified as the most promising due to its high shell weight, very good fuel properties, and high yield potential. This study underscores the importance of selecting the right variety to optimize agricultural waste utilization strategies within a circular economy. Full article

Background: Colorectal cancer (CRC) is among the leading causes of cancer-related mortality worldwide, with increasing attention being paid to modifiable dietary factors in its prevention. Hazelnut (Corylus avellana L.) represent a nutrient-dense food rich in unsaturated fats, polyphenols, fiber, and phytosterols, with potential anticarcinogenic properties. This systematic review aimed to evaluate the role of hazelnut consumption in the prevention and modulation of CRC risk, with specific focus on experimental, mechanistic, and preclinical evidence. Methods: Following PRISMA guidelines, a systematic search was conducted in PubMed, Google Scholar, and the Cochrane Library for articles published from 2015 onward. Eligible studies included original in vitro and in vivo models, as well as observational studies, evaluating hazelnut or hazelnut-derived products in relation to CRC-related biological, metabolic, or clinical outcomes. Data extraction focused on bioactive composition, experimental models, molecular pathways, and fecal/metabolic markers of carcinogenesis. Results: A total of 11 studies were included after screening 24 records: 8 in vitro investigations, 2 in vivo animal experiments, and 1 epidemiological study. In vitro studies showed that hazelnut derivatives—including fermented hazelnuts and oil-based extracts—exert antiproliferative effects via BAX/BCL-2 modulation, increased caspase-3 activity, and oxidative stress reduction. In vivo studies confirmed improved lipid metabolism, modulation of bile acid composition (notably reduced lithocholic/deoxycholic acid ratio), and enhanced antioxidant defenses. FIBEROX^®, a hazelnut skin extract enriched in dietary fiber, demonstrated promising effects on gut microbiota and bile acid detoxification. Conclusions: Hazelnut and their bioactive compounds may aid CRC prevention through multiple molecular and metabolic pathways. Further human studies are needed to confirm these effects and support dietary recommendations. Full article

Currently, there is an ever-increasing demand for organic food from consumers who are convinced that it is healthier and more nutritious. The purpose of our research was to carry out an evaluation of the nutritional and sensory characteristics of organic and conventional hazelnuts of Tonda Gentile Romana cv. To this end, volatile composition, total phenolics, antioxidant capacity, and sensory profile of organic and conventional hazelnuts were identified. In comparison to conventional hazelnuts, organic hazelnuts had a greater amount of total phenols and antioxidants. Furthermore, organic hazelnuts had a different sensory profile, with more crunchiness (6.722 vs. 4.056 for raw and 8.389 vs. 4.667 for roasted) and sweetness (7.667 vs. 4.867 for raw and 7.089 vs. 3.889 for roasted), accompanied by distinct hazelnut, almond, walnut, popcorn, coffee, and roasty notes, present in much higher amounts than conventional hazelnuts. One of our key findings is that organic hazelnuts have a higher nutritional value due to their higher antioxidant capacity. Promoting organic hazelnuts helps to encourage consumers to use these products, which have a high nutritional value, thus contributing to public health. Full article

Background: Understanding the mechanisms by which woody perennials adapt to extreme water deficits is important in regions experiencing increasingly frequent and intense droughts. Methods: We investigated the effects of drought severity in the shrubs Corylus avellana L., C. maxima Mill., and their morphological intermediate forms, all from local Belgian origin, and C. avellana from a Spanish-Pyrenean origin. Potted saplings in a common garden were not receiving any water for a duration of 30 days in July 2021 and developed a range of visual stress symptoms. We assessed responses across the various symptom categories. Results: Droughted plants senesced later than the controls (up to 6 days). The most severely affected plants disproportionately displayed the longest delay (21 days). The delayed leaf senescence was reflected in the subsequent bud burst which was delayed for the droughted plants, with again the largest delay observed for the most severely affected plants. Interestingly, radial growth shifted towards the autumn among the drought-treated plants, suggesting compensation growth after growing conditions normalized. The Spanish-Pyrenean provenance, characterized by smaller plants with smaller leaves, developed visual drought symptoms later than the local provenance during the drought. Conclusions: The results indicate that severe early summer drought, followed by rewatering, not only diminishes radial growth but also prolongs the growth period, and delays leaf senescence. A prolonged time frame for radial growth and a delayed leaf senescence indicate a longer period in which carbon is incorporated in woody tissue or in non-structural carbohydrates. This can help the fine tuning of carbon sequestration modeling. The Pyrenean provenance, adapted to high altitude, holds an advantage under water-limited conditions. Full article

Considerable amounts of agro-industrial by-products are discarded every year. Moreover, these represent an interesting source of phenolics, cellulose and lignin, in addition to useful compounds such as antioxidants. However, these compounds may be affected by external factors such as genotype, locality and productive season, increasing or decreasing the antioxidant potential of by-products. In this study, hazelnut (Corylus avellana L.) and walnut (Juglans regia L.) nutshells were investigated for their fiber content and antioxidant capacity as valorized by-products in this industry. The determination of oxygen radical absorbance capacity (ORAC), total phenolic content (TPC) and color difference was performed using hazelnut and walnut shells collected from orchards located in Southern Chile during three consecutive seasons (2020/21, 2021/22 and 2022/23). The ORAC in nutshells showed the highest values in both species for the season 2020/21 (3217 and 4663 µmol TE g DW⁻¹ for hazelnut and walnut), whereas the variability in consecutive seasons was lower for hazelnut than for walnut. The TPC in hazelnut shells was positively correlated with L* (R: 0.883) and ΔE (r = 0.924) during the 2020/21 season and with L* for 2022/23 (r = 0.907). On the other hand, the ORAC was negatively correlated with L* (r = 0.922) in 2021/22. In addition, the morphological and structural features of both nutshells examined by scavenging electron microscopy (VP-SEM) and confocal scavenging laser microscopy (CSLM) revealed differential tissue distribution and accumulation patterns of both cellulose and lignin. In addition, photo-colorimetric values were determined for both shells and corresponding seasons, and non-significant differences were found for both shells and among seasons. Finally, our results provide new insights into the physicochemical characteristics of these two types of nutshells as valorized by-products, considering their antioxidant properties as residual materials derived from this agroindustry. Full article

Chile contributes 4% of global hazelnut (Corylus avellana L.) production, mainly developed in temperate regions with high autumn rainfall and humidity during harvest, which can compromise nut quality and increase postharvest losses. Thus, synchronizing harvests has become a critical aspect for growers in the southern region of Chile. This study focused on the effects of ethephon (ETH) spraying on trees to optimize nut drop timing and assess its impact on yield optimization and its influence on vegetative growth and inflorescence activity. From the 2020/2021 to the 2022/2023 seasons, experiments were conducted on a commercial hazelnut orchard of Tonda di Giffoni (TDG) planted in southern Chile. Four ETH (0, 250, 500, 1000 mg L⁻¹) treatments were sprayed 15 days preharvest and denoted as ETHA (sprayed 2020/2021) and ETHB (sprayed twice, in 2020/2021 and 2021/2022). Nut drop synchronization was periodically monitored at 7, 15, 21, 28, and 35 days after application (DAA), along with industrial quality parameters (nut weight, kernel yield) and inflorescence activity. In the first season, ETH significantly synchronized nut drops, achieving optimal results at 15–28 DAA with ETH 250 and 500, while ETH 1000 induced earlier drops but reduced yields. Total nut yield varied among seasons and demonstrated consistent performance of ETH 250, identified as the most efficient treatment for balancing nut drop timing. Industrial parameters showed seasonal differences but no adverse effects on nut quality. Conversely, the inflorescence activity remained unaffected by ETH concentrations. ETHA and ETHB treatments influenced tree shoot length variably across three seasons, showing significant concentration and seasonal interaction effects. These results demonstrate that ETH effectively synchronizes hazelnut harvests under temperate conditions, reducing post-harvest losses and optimizing logistics without compromising yield or quality. Full article

Hazelnut (Corylus avellana L.) oil production generates press cakes, a by-product rich in plant-based proteins. As demand for alternative proteins grows, sustainable extraction methods like deep eutectic solvents (DESs) are essential for reducing the environmental impact. Alkali solubilization/isoelectric precipitation (ALKIS) is a widely used method for protein extraction due to its simplicity and cost-effectiveness. Despite that, ALKIS extraction has limitations due to the alteration in protein functionality, a reduction in protein stability, and significant wastewater production. This study compares DESs with ALKIS for extracting proteins from hazelnut press cake. ALKIS resulted in higher protein content (42.53 ± 17.45% vs. 8.55 ± 1.68%), while DES extraction showed higher efficiency (56.41 ± 2.4% vs. 45.16 ± 5.32%). FTIR analysis revealed significant structural differences: DES-extracted proteins exhibited higher β-sheet content (α-helix peak: 31.55 ± 6.97% vs. 18.13 ± 1.15%, p = 0.0302), indicating enhanced stability, whereas ALKIS-extracted proteins had more random coil structures (β-sheet peak: 57.92 ± 3.12% vs. 34.07 ± 12.45%, p = 0.0324), suggesting partial denaturation. The preservation of native protein structures in DES extraction is likely due to hydrogen bonding networks that stabilize proteins during processing. Full article

Commercial hazelnut (Corylus avellana L.) production is relatively new to Ontario and there are no Ontario-specific fertility recommendations for this crop. With the increasing numbers of hazelnut growers entering the industry and the number of acres coming into full production capacity, this was identified as a gap. A 3-year trial was conducted to look at how four different fertility treatment regimes impact hazelnut growth and yield: (1) Ontario’s guidelines for established tree fruits, (2) Modified Oregon’s guidelines for hazelnuts, (3) Grower’s management, and (4) Control (with no external fertilizers). Four pilot demonstration sites were also established to compare fertilized plots (e.g., Ontario’s guidelines for established tree fruits) with orchard-specific grower’s management. Location-specific soil and tissue tests were conducted to determine the amount of fertilizer to apply to each orchard. Hazelnut yields and economic returns varied with location, tree age, and market price of hazelnuts; however, fertilized treatment (e.g., Ontario’s guidelines for established tree fruits) outperformed the grower’s management by up to 75 percent with net economic returns of CAD 18–44 per tree. In the orchard where all four fertility treatments were compared, yields and economic returns from modified Oregon treatment and Ontario recommendation were not statistically different. However, they outperformed grower’s management by 44 and 42 percent, respectively. Modified Oregon and Ontario treatment yielded ~7.0 pounds (lb) per tree with a net economic return of CAD 27 per tree during the 3rd year of study, while grower’s management and control treatments yielded 4.8 and 4.0 lb per tree with net economic returns of CAD 19 and 16 per tree, respectively. Also, fertilized treatments showed higher levels of residual nutrients of N, P, and K in the soil and the leaf tissues. The project results supported that Ontario’s fertility guidelines for established tree fruits can be used for commercial hazelnut production on mineral soils in Ontario. Also, testing soils every three years or plant tissues every year could help match applied nutrients more closely with plant demand, thereby enhancing economical and ecological sustainability. Full article

Chile has become a significant producer of hazelnuts (Corylus avellana L.) due to its favorable conditions for off-season production to meet global market demand. Efficient light interception is crucial for optimizing the hazelnut yield and quality, as it directly influences the plant’s photosynthetic capacity. The goal was to assess the impact of intercepted photosynthetically active radiation (PAR) at upper, middle, and lower canopy levels in hazelnut trees grown at different planting densities and the canopy management of yield and quality parameters. The percentage of vain, sucker, double, bug, and healthy hazelnuts, including the number of fruits, total fruit weight, and grams per fruit was evaluated. The upper canopy levels intercepted the highest PAR, significantly enhancing the number and weight of fruits. The lower canopy levels received considerably less PAR, reducing the productivity. Production pruning in dense planting systems (5 × 3 m) improved the light penetration compared to a less dense planting density (5 × 6 m). Strong positive correlations were observed among PAR, fruit weight, and fruit number, emphasizing the importance of the light distribution within the canopy in hazelnut production. Production pruning and optimized planting densities are essential for maximizing light interception, improving yield, and ensuring high-quality hazelnut production. Full article

The aim of this study was to determine the influence of the nut roasting process (conventional and microwave methods) and long-term storage (12 months) on phytosterol content and stability. This study was conducted using hazelnuts (Corylus avellana), common walnuts (Juglans regia L.), and shelled peanuts (Arachis hypogaea L.). Two roasting methods were examined: conventional (temp. 170 °C, roasting time 10–20 min.) and microwave (temp. 60 °C, pressure 40 hPa, roasting time 140–180 s). In the studied nuts (raw, roasted and stored), five main types of phytosterols were identified: campesterol, stigmasterol, ß-sitosterol, delta 5-avenasterol and cycloartenol. It was shown that the microwave roasting method caused a two-fold decrease in sterol loss compared with conventional roasting. Moreover, the long-term storage of roasted walnuts using the microwave method showed double the amount of sterols preserved compared with those roasted using the conventional method. The amount of ß-sitosterol, which was the most stable during roasting, depended more on storage duration than on roasting process. The cycloartenol content in the roasted nuts did not depend on storage duration. The sterols present in nuts, raw or roasted using either method, transform more during the first 6 months of storage. Full article

The European hazelnut is a temperate nut crop, often managed as a multi-stemmed shrub due to its natural aptitude to produce several suckers at the base of the stump, depending on variety. Traditional hazelnut-growing regions such as Italy, Turkey, and Spain typically adopt this architecture, while other hazelnut-producing countries such as the USA, France, and Chile increasingly use single-trunk systems to facilitate orchard management. Multi-stemmed plants allow gradual renewal through sucker selection but may lead to excessively dense canopies, reducing the effectiveness of pest and disease control, increasing biennial bearing, and lowering nut yields in vigorous cultivars. In order to drive the ongoing enlargement of hazelnut cultivation, attempts in designing high-density (HD), and more occasionally super-high-density (SHD), hazelnut orchards are on-going, although these are poorly explored in terms of suitable plant training systems, such that, sometimes, multi-stemmed plant shapes are used; otherwise, single-trunk solutions are adopted. In order to explore new hazelnut planting and training solutions focused on sustainable intensification, a trial was established in 2019 in central Italy to evaluate the eligibility of three training systems (treatment A: regular four-stemmed shrub; treatment B: single-trunk sapling; treatment C: traditional multi-stemmed shrub), applied on unpruned three-year-old plants of the hazelnut cultivar Nocchione, planted in the HD approach (740 plant ha⁻¹). Over five growing seasons (2019–2023), measurements included pruned wood removed, yield, vigor, yield efficiency, nut and kernel traits, and incidence of the main commercial defects. In general, treatment A outperformed other plant-shaping systems, maintaining high yield levels particularly in the two last growing seasons, and showing a mean kernel/nut ratio of 37.7 and a low incidence of defects. Treatment B achieved the highest yield efficiency in 2023 but had lower overall yields. Treatment A demonstrated the most balanced performance, combining high nut quality and stable production, making it the most promising plant training system for HD hazelnut orchards with planting densities above 700 plants per hectare. Future research will assess the long-term adaptability of this plant training system under varying environmental and management conditions. Full article

Rising soil salinity poses a significant challenge to hazelnut cultivation, particularly in Mediterranean regions, where the increasing use of low-quality irrigation water necessitates the identification of salt-tolerant cultivars for sustainable production. This study investigated the salt tolerance mechanisms in four hazelnut cultivars (Barcelona, Tonda di Giffoni, Tonda Gentile Romana, and Yamhill) exposed to varying NaCl concentrations (0, 25, 50, and 75 mM) over five months. This research assessed their morphological, physiological, and biochemical responses through an analysis of their growth parameters, photosynthetic efficiency, visual symptoms, and ion content. The results revealed significant genotypic variation in their salt tolerance mechanisms. Tonda di Giffoni demonstrated superior salt tolerance, maintaining a higher photosynthetic efficiency and better ion balance, particularly in K⁺/Na⁺ and Ca²⁺/Na⁺ ratios. Barcelona showed moderate tolerance at lower salinity levels but declined sharply under higher stress. Yamhill exhibited a strong survival capacity despite its poor photosynthetic performance, while Tonda Gentile Romana proved most sensitive to salinity stress. All the cultivars showed a significant biomass reduction, with their fresh and dry weights decreasing by over 80% at 75 mM NaCl. Leaf chloride concentrations dramatically increased, reaching levels 481% higher than those in the control conditions. This study identifies Tonda di Giffoni as the most suitable cultivar for moderately saline conditions and provides insights into hazelnut salt tolerance mechanisms, contributing valuable information for breeding programs and cultivation strategies in salt-affected regions. Full article

This study presents the results of two on-farm trials evaluating the efficacy of a nitrogen (N)-fixing inoculant (Methylobacterium symbioticum) applied as a foliar spray to provide N to hazelnut (Corylus avellana L.) and walnut (Juglans regia L.) trees. In the hazelnut trial, a factorial design was employed with soil N application at three levels [0 (N0), 40 (N40), and 80 (N80) kg ha⁻¹] and foliar application of the inoculant (Yes and No). The walnut trial was arranged as a completely randomized design with three treatments: the N-fixing microorganism, a seaweed extract, and a control. Soil N application significantly increased hazelnut yield in 2021 (1.99, 2.49, and 2.65 t ha⁻¹ for N0, N40, and N80, respectively) but not in 2022 (average values ranging from 0.28 to 0.33 t ha⁻¹). The inoculant application did not significantly affect hazelnut yield. In the walnut trial, no significant differences were observed among the treatments in either year. The average yields ranged from 1.72 to 2.38 t ha⁻¹ in 2021 and 0.66 to 0.84 t ha⁻¹ in 2022. Soil N application in hazelnuts tended to increase leaf N concentration and significantly increased kernel N concentration. The inoculant increased leaf N concentration in one of the three sampling dates but did not affect kernel N concentration. In walnuts, the inoculant did not increase leaf N concentration but significantly increased kernel N concentration in one of the two years. The seaweed extract did not influence walnut yield or leaf N concentration. None of the treatments in either trial consistently affected the concentration of other macronutrients and micronutrients in the leaves. Therefore, while the inoculant showed some potential to improve the N nutritional status of the trees, it did not affect the yield. Overall, the results of the inoculant application were not sufficiently compelling, indicating the need for further studies on these species before the commercial product can be confidently recommended to farmers. Full article

Fungal trunk disease (FTD) poses a significant threat to hazelnut (Corylus avellana L.) production worldwide. In Chile, the fungus Diplodia mutila, from the Botryosphaeriaceae family, has been frequently identified causing this disease in the Maule and Ñuble Regions. However, control measures for D. mutila remain limited. This research aimed to evaluate the effectiveness of chemical and biological fungicides against D. mutila under in vitro, controlled pot experiment, and field conditions. An in vitro screening of 30 fungicides was conducted. The effectiveness was assessed by measuring the length of vascular lesions in hazelnut branches inoculated with D. mutila mycelium disks under controlled and field conditions. Field trials were conducted in a hazelnut orchard in Ñiquén, Ñuble Region, Chile. The results showed that three biological and five chemical fungicides were selected in vitro with >31% inhibition after 14 days. In pot experiments, all fungicides reduced necrotic lesions on branches by 32% to 61%. In field experiments, the most effective systemic fungicides were fluopyram/tebuconazole, fluxapyroxad/pyraclostrobin, and tebuconazole, while the effectiveness of antagonists Pseudomonas protegens ChC7 and Bacillus subtilis QST713 varied with seasonal temperatures. Effective conventional and biological fungicides against D. mutila could be integrated into disease management programs to protect hazelnut wounds from infections. Full article