Search Results (395)

This study investigated meat analogs produced by high-moisture extrusion from mixtures of pea protein isolate and soryz flour, and chickpea flour and hazelnut meal in a 1:1 ratio, at two distinct heating temperature profiles: 40-60-80-100 °C and 60-80-100-120 °C. Physicochemical indicators, texture and chromatic parameters, protein digestibility, and antioxidant activity of the meat analogs were assessed, and antioxidant activity of the product in terms of simulating gastrointestinal digestibility in vitro was performed. The results obtained for the analyzed meat analog indicators were greatly influenced by the type of plant-based raw material used and the heating temperature profiles. A higher temperature regime leads to a slight decrease in the content of nutritive compounds in the final products. All meat analog samples showed good water and oil holding capacity. A decrease in hardness was observed for the mixtures compared to pea protein isolate, which can be attributed to protein content. The digestibility of the processed meat analog proteins ranged between 86.84% and 69.37%. PCA was applied to illustrate the relationships between physicochemical characteristics, protein digestibility, antioxidant activity, texture profile analysis, and CIELab color parameters in high-moisture meat analogs. Full article

The consumption of animal- and plant-based protein food is increasing as the world population grows. Alternative protein sources that are nutritious, safe and sustainable are needed. There is a growing research interest in integrating wheat-based staple foods, such as pasta, with new ingredients that could also provide nutritional and health benefits. Despite their unquestionable nutritional value, new pasta formulations need to be evaluated in terms of technological/sensory quality. In this study, we assessed the quality and flavour of traditional egg pasta fortified with two alternative protein sources: hazelnut flour and cricket powder. It is known that a quality pasta tends to lose fewer solids during cooking. In parallel with classical evaluation of cooking and sensory characteristics, proton nuclear magnetic resonance (¹H NMR) spectroscopy of the metabolites released during the cooking process and volatile fingerprint analysis with quartz microbalance (QMB) electronic nose (E-nose) were performed. These approaches showed results complementary to those obtained from classical quality and sensory analyses, thus demonstrating the potential of ¹H NMR and E-nose in pasta quality assessment. Overall, the pasta fortification with cricket powder and hazelnut flour affected the matrix mobility by modulating the release of chemical components into the water during cooking and overcooking processes; moreover, it significantly altered the pasta sensory profile in terms of aroma and texture. This finding highlights the complexity of balancing technological improvement with sensory appeal in food product development. Full article

Hazelnuts are valuable for human health and nutrition. They are also an economically important type of nut. This study was conducted to determine the effect of different geographical origins (Giresun, Ordu, and Samsun/Türkiye) on the nut characteristics, bioactive compounds, and fatty acid composition of three hazelnut cultivars (cvs. Çakıldak, Palaz, and Tombul). The highest nut and kernel weights and sizes were determined to be in all cultivars in Samsun. The highest kernel ratio was recorded in the Çakıldak and Palaz cultivars grown in Giresun. However, shell thickness was not affected by geographical origin. The highest levels of total phenolics and total flavonoids were recorded in all cultivars in Samsun. The antioxidant activity of the cultivars differed according to geographical origin. The highest oleic acid was found in all cultivars in Giresun, while the highest linoleic acid was observed in those grown in Ordu. Generally, the highest results in terms of other fatty acids were recorded in all cultivars in Samsun. According to the results of the principal component analysis (PCA), the cultivars grown in the Samsun region were generally related to better nut traits and phenolics, while the cultivars grown in the Giresun and Ordu regions were associated with better antioxidant activity and fatty acid composition. This study shows that the nut traits, bioactive compounds, and fatty acid composition of hazelnuts are affected by geographical differences. These results provide valuable insights for hazelnut growers and the food industry. Full article

The study aimed to produce semolina pasta enriched with walnut or hazelnut oil cake and to investigate its nutritional and technological properties. The pasta was prepared by substituting 10% of semolina with walnut or hazelnut oil cakes. The chemical composition, antioxidant properties, and culinary characteristics of the pasta were determined. Additionally, the texture and color of uncooked and cooked pasta were examined using instrumental techniques. The enriched pastas showed higher protein, fat, ash, and dietary fiber contents compared to standard pasta (SP). Walnut oil cake pasta (WOCP) had the highest protein content, amounting to 15.8 g/100 g dry weight (d.w.), while hazelnut oil cake pasta (HOCP) had the highest dietary fiber content (6.75 g/100 g d.w.). Moreover, the enriched pastas showed significantly higher antioxidant potential and total phenolic content, both before and after cooking. The total phenolic content (TPC) of cooked pasta ranged from 88.85 mg GAE/100 g d.w. (SP) to 145.48 mg GAE/100 g d.w. (WOCP). Compared to SP, the developed pastas required cooking times of 2–3 min longer and showed higher water absorption, accompanied by increased cooking losses. They were characterized by a specific, dark color and showed reduced hardness and lower elasticity after cooking compared to SP. Pasting properties further suggested that starch swelling was restricted by the nut oil cakes. Overall, incorporating walnut and hazelnut oil cakes enhanced the nutritional profile and imparted notable health-promoting attributes to the pasta, underscoring the potential of these by-products as functional ingredients in pasta formulations. Full article

This study investigated the potential of hazelnut wood (Corylus avellana L.) as an alternative raw material in the production of single-layer structural particleboards. Boards with a target density of 700 kg m⁻³ and thickness of 13 mm were manufactured using varying substitution levels (5%, 10%, 25%, 50% and 100%) of hazel wood particles relative to industrial pine (Pinus sylvestris L.) particles. Phenol-formaldehyde (PF) resin was used as the adhesive at a 15% resination rate. Mechanical and physical properties, including modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), screw withdrawal resistance (SWR), water absorption (WA), and thickness swelling (TS), were evaluated according to relevant European standards. Density profiles (DP) were also assessed. The results showed that while higher hazel content reduced bending strength (from 23.3 N mm⁻² for reference to 18.7 N mm⁻² for 100% hazel wood board) and stiffness (from 3515 N mm⁻² for reference to 2520 N mm⁻² for 100% hazel wood board), most boards met standard mechanical requirements of EN 312 for P3 and P5 boards. Notably, IB strength improved significantly at higher hazel content, with the 100% variant (2.07 N mm⁻²) exceeding the reference board (1.57 N mm⁻²). Screw withdrawal resistance also increased with hazel wood addition (from 235 N mm⁻¹ for reference to 262 N mm⁻¹ for 100% hazel wood board), linked to its higher density. However, water resistance and dimensional stability worsened with increasing hazel content, particularly in bark-containing particles, leading to excessive thickness swelling after prolonged water exposure. Thickness swelling after 24 h of soaking rose from 16.36% for the reference board to 20.13% for the 100% hazel wood board. Density profiles revealed a more uniform internal structure in boards with higher hazel content. Overall, hazelnut wood shows promise as a partial substitute for pine in particleboard production, especially at moderate substitution levels, though limitations in moisture resistance must be addressed for broader industrial application. Full article

Nut-based plant beverages are gaining recognition for their functional properties and nutritional value in bakery applications. This study evaluated the effects of substituting water with hazelnut (BH), walnut (BW), and almond (BA) beverages in wheat bread formulations at four substitution levels (25–100%). Thirteen bread variants, including a control, were produced using the straight dough method. The impact of substitution on dough performance, crumb structure, texture, color, physicochemical composition, and sensory attributes was evaluated. All nut beverages improved bread yield, with BA100 and BW100 showing the highest values. Crumb moisture was well retained, and baking losses were reduced in some high-substitution variants. Medium-sized pores (0.1–0.9 mm²) dominated crumb structure, particularly in almond-enriched breads, which contributed to desirable loaf volume and crumb elasticity. Walnut beverage significantly darkened the crumb due to natural pigments, while BA and BH maintained lighter tones and enhanced yellowness. Nut-based beverages increased ash and fat content, with BW breads showing the highest caloric values—mainly due to beneficial unsaturated fats. Sensory evaluation confirmed high consumer acceptability, with the highest ratings observed for breads containing 100% walnut and 50–75% almond beverage. These variants demonstrated the most favorable balance of technological performance and nutritional enhancement, underscoring their potential as optimal formulations for clean-label, plant-based bread products. Full article

Hazelnut is an important crop worldwide, and the characteristics of the fruits are quite variable according to a number of factors, including variety and cultivation conditions, which in turn can vary according to harvest year. This study aimed to investigate some physical and chemical characteristics of three hazelnut varieties grown in Portugal (Grada de Viseu, Tonda di Giffoni and Butler) along two different harvesting years (2021 and 2022). Also, the microbial quality was investigated for its relevance to the conservation of the fruits. The physical properties evaluated were biometric characteristics and colour, the chemical components analysed were moisture, lipids, protein, ash and fibre, and the microbial properties investigated were the microorganisms, moulds and yeasts. The results showed that, generically, statistically significant differences were found between the three varieties under study on several properties investigated. The kernel was confirmed as the lighter part of all hazelnuts, and when comparing between varieties, Tonda di Giffoni presented the lighter fruits in both harvesting years. With respect to weight, the Tonda di Giffoni variety was the lightest in both harvest years. Moisture content was observed to be higher than the recommended limits for two of the samples (Grada de Viseu in 2021: 6.01 ± 0.26 g/100 g and Butler in 2022: 6.02 ± 0.37 g/100 g), although the difference was marginal given that the recommended limit is 6%. Not surprisingly, lipids were the major chemical component, ranging from 66.46 ± 1.67 to 70.14 ± 1.75 g/100 g in 2021 and from 64.38 ± 1.67 to 77.77 g/100 g in 2022. It was further observed that the three varieties presented a satisfactory microbiological quality. Finally, applying factor analysis with principal components and Varimax rotation, a solution that explains 92.8% of the variance was obtained. This study provided information that is relevant for the characterisation and evaluation of variability according to the year of hazelnuts of three varieties cultivated in Portugal. Full article

The growing demand for sustainable plant-based dairy alternatives has spurred interest in valorizing agro-industrial byproducts like hazelnut cake, a protein-rich byproduct of oil extraction. This study developed formulations for vegan ice cream using unfermented (HIC) and Aspergillus oryzae-fermented hazelnut cake (FHIC), comparing their physicochemical, functional, and sensory properties to conventional dairy ice cream (DIC). Solid-state fermentation (72 h, 30 °C) enhanced the cake’s bioactive properties, and ice creams were characterized for composition, texture, rheology, melting behavior, antioxidant activity, and enzyme inhibition pre- and post-in vitro digestion. The results indicate that FHIC had higher protein content (64.64% vs. 58.02% in HIC) and unique volatiles (e.g., benzaldehyde and 3-methyl-1-butanol). While DIC exhibited superior overrun (15.39% vs. 4.01–7.00% in vegan samples) and slower melting, FHIC demonstrated significantly higher post-digestion antioxidant activity (4.73 μmol TE/g DPPH vs. 1.44 in DIC) and angiotensin-converting enzyme (ACE) inhibition (4.85–7.42%). Sensory evaluation ranked DIC highest for overall acceptability, with FHIC perceived as polarizing due to pronounced flavors. Despite textural challenges, HIC and FHIC offered nutritional advantages, including 18–30% lower calories and enhanced bioactive compounds. This study highlights fermentation as a viable strategy to upcycle hazelnut byproducts into functional vegan ice creams, although the optimization of texture and flavor is needed for broader consumer acceptance. Full article

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

This study evaluated the authenticity of olive oil in canned tuna products from the Slovenian market using both official methods, including fatty acid (FA) profiling, determination of the equivalent carbon number difference (ΔECN42), and sterol analysis, and an advanced method: stable carbon isotope analysis (δ¹³C) of FAs obtained through compound-specific isotope analysis (CSIA). Results from both methods confirmed that all 10 samples were authentic, as per the limits set by EU Regulation 2022/2104 and supported by the scientific literature. Method performance was further evaluated by adulterating the olive oil from the canned tuna with 5–20% vegetable oil (VO) or hazelnut oil (HO). While FA analysis struggled to differentiate adulterants with similar FA profiles, CSIA of FAs significantly improved detection. However, distinguishing between VO and HO blended samples remained challenging. PLS-DA analysis further supported the potential of using δ¹³C values of FA for food authentication. Storage of adulterated samples also influenced FA composition, leading to significant changes in MUFA/PUFA ratios and δ¹³C values, which became less negative, likely due to oxidative degradation. In summary, the combination of official and advanced methods, supported by chemometric analysis, offers a robust approach to ensuring the authenticity of olive oil in canned tuna. Full article

Consumer perceptions of upcycled foods, as well as the determinants of food choices, are still not well understood. The aim of this study was to evaluate the impact of psychological and personal traits on purchase intention (PI) towards upcycled foods of Italian consumers. Additionally, willingness to try (WTT), willingness to buy (WTB), and willingness to pay (WTP) for yogurt, bread, and biscuits made with by-products, namely, hazelnut skin and grape pomace powder, were collected. A web-based survey involving 505 consumers was conducted, and partial least squares structural equation modeling (PLS-SEM) was used to evaluate the model. It resulted that food neophobia and attitude towards upcycled foods had a significant impact on PI. In turn, attitude was affected by food neophobia as well as by objective knowledge about food by-products. Unexpectedly, frugality and environmental concern did not affect PI. WTP was product-specific; when WTP was compared to a reference price, it was higher for the yogurt prototype, followed by the bread and biscuits prototypes. Food neophobia affected WTT, WTB, and WTP. This study contributes to providing new insights into the determinants of consumers’ purchase intention for upcycled foods, which are an emerging category of products. Full article

The exponential increase in electronic waste (e-waste) from end-of-life electrical and electronic equipment presents a growing environmental challenge. E-waste contains high concentrations of rare earth elements (REEs), which are classified as critical raw materials (CRMs). Their removal and recovery from contaminated systems not only mitigate pollution but also support resource sustainability within a circular economy framework. The present study proposed the use of hazelnut shells as a biosorbent to reduce water contamination and recover REEs. The sorption capabilities of this lignocellulosic material were assessed and optimized using the response surface methodology (RSM) combined with a Box–Behnken Design (three factors, three levels). Factors such as pH (4 to 8), salinity (0 to 30), and biosorbent dose (0.25 to 0.75 g/L) were evaluated in a complex mixture containing 9 REEs (Y, La, Ce, Pr, Nd, Eu, Gd, Tb and Dy; equimolar concentration of 1 µmol/L). Salinity was found to be the factor with greater significance for REEs sorption efficiency, followed by water pH and biosorbent dose. At a pH of 7, salinity of 0, biosorbent dose of 0.75 g/L, and a contact time of 48 h, optimal conditions were observed, achieving removals of 100% for Gd and Eu and between 81 and 99% for other REEs. Optimized conditions were also predicted to maximize the REEs concentration in the biosorbent, which allowed us to obtain values (total REEs content of 2.69 mg/g) higher than those in some ores. These results underscore the high potential of this agricultural waste with no relevant commercial value to improve water quality while providing an alternative source of elements of interest for reuse (circular economy). Full article

In this study, carbon adsorbents obtained from agricultural waste, i.e., walnut, hazelnut, and pistachio nutshells, were investigated for the removal of paracetamol (acetaminophen, 4-hydroxyacetanilide) (PAR) from aqueous solutions. Activated carbons (ACs) were produced via a two-step procedure. In the first step, the carbonization of nutshells was carried out at 600 °C, and in the second step, the chemical activation was carried out at 750 °C using alkaline activators, i.e., NaOH and KOH. For all of the ACs obtained and characterized, PAR adsorption kinetics, the adsorption at equilibrium, and the effects of the solution pH were investigated. All results obtained for each nutshell depend on the type of activating agent used. However, in the case of a given activator, there are differences resulting from the type of raw material. Kinetic and isothermal studies revealed that PAR adsorption follows the pseudo-second-order and the Langmuir models, respectively. The adsorption capacities of the ACs were very high and ranged from 332.2 to 437.8 mg/g. This study highlights the remarkable potential of nutshells as valuable and cost-effective precursors for the production of ACs that can effectively remove paracetamol from water. Full article

Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) are powerful techniques that have been employed to analyze foodstuffs comprehensively. These techniques offer in-depth information about the chemical composition, structure, and spatial distribution of components in a variety of food products. Quantitative NMR is widely applied for precise quantification of metabolites, authentication of food products, and monitoring of food quality. Low-field ¹H-NMR relaxometry is an important technique for investigating the most abundant components of intact foodstuffs based on relaxation times and amplitude of the NMR signals. In particular, information on water compartments, diffusion, and movement can be obtained by detecting proton signals because of H₂O in foodstuffs. Saffron adulterations with calendula, safflower, turmeric, sandalwood, and tartrazine have been analyzed using benchtop NMR, an alternative to the high-field NMR approach. The fraudulent addition of Robusta to Arabica coffee was investigated by ¹H-NMR Spectroscopy and the marker of Robusta coffee can be detected in the ¹H-NMR spectrum. MRI images can be a reliable tool for appreciating morphological differences in vegetables and fruits. In kiwifruit, the effects of water loss and the states of water were investigated using MRI. It provides informative images regarding the spin density distribution of water molecules and the relationship between water and cellular tissues. ¹H-NMR spectra of aqueous extract of kiwifruits affected by elephantiasis show a higher number of small oligosaccharides than healthy fruits do. One of the frauds that has been detected in the olive oil sector reflects the addition of hazelnut oils to olive oils. However, using the NMR methodology, it is possible to distinguish the two types of oils, since, in hazelnut oils, linolenic fatty chains and squalene are absent, which is also indicated by the ¹H-NMR spectrum. NMR has been applied to detect milk adulterations, such as bovine milk being spiked with known levels of whey, urea, synthetic urine, and synthetic milk. In particular, T2 relaxation time has been found to be significantly affected by adulteration as it increases with adulterant percentage. The ¹H spectrum of honey samples from two botanical species shows the presence of signals due to the specific markers of two botanical species. NMR generates large datasets due to the complexity of food matrices and, to deal with this, chemometrics (multivariate analysis) can be applied to monitor the changes in the constituents of foodstuffs, assess the self-life, and determine the effects of storage conditions. Multivariate analysis could help in managing and interpreting complex NMR data by reducing dimensionality and identifying patterns. NMR spectroscopy followed by multivariate analysis can be channelized for evaluating the nutritional profile of food products by quantifying vitamins, sugars, fatty acids, amino acids, and other nutrients. In this review, we summarize the importance of NMR spectroscopy in chemical profiling and quality assessment of food products employing magnetic resonance technologies and multivariate statistical analysis. 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