Study on techno-functional properties of pecan flour with different lipid content
Pecan flour, obtained from the solid residue left after walnut oil extraction, is rich in proteins, dietary fiber, and phenolic compounds with antioxidant properties. This study evaluates the techno-functional properties of pecan flour with varying lipid contents. Key parameters include color (L*, a*, and b* values), bulk density, oil absorption capacity (OAC), water absorption capacity (WAC), emulsifying activity (EA), and stability (ES). A two-way factorial design was used to assess WAC, EA, and ES while varying pH and NaCl concentrations. Low-lipid pecan flour (20.7% ± 0.51%) showed a higher OAC (3.990% ± 0.024%) and a light beige color, while high-lipid flour (68.7% ± 0.61%) had a dark brown color and greater bulk density (0.532 ± 0.003 g/mL versus 0.217 ± 0.005 g/mL). WAC increased significantly in low-lipid flour at higher pH and lower NaCl levels, whereas high-lipid flour required higher NaCl concentrations to optimize WAC. EA and ES peaked at intermediate pH and NaCl levels, with low-lipid flour demonstrating superior emulsion properties due to its favorable hydrophilic-hydrophobic balance. The study highlights the complex interactions between pH, NaCl, and lipid content, significantly influencing WAC, EA, and ES. These findings provide insights for optimizing the functionality of pecan flour in food formulations. Also, the research establishes pecan flour as a promising ingredient for enhancing water retention and emulsion stability in food systems, contributing to sustainable food innovations and offering the potential for further exploration in complex food matrices.
https://doi.org/10.1590/1981-6723.10624
Integration of Destructive and Non‐Destructive Analytical Determinations for Evaluating Quality of Fresh and Roasted Hazelnuts Subjected to Different Processing Temperatures
The internal quality of hazelnuts (Corylus avellana L.), particularly in terms of the degradation of fat components, is widely recognized as a key factor in determining the appropriate type of industrial processing. Additionally, the internal composition and volatile profile of hazelnuts change significantly based on different roasting conditions. The here reported study investigates the efficiency of Electronic Nose (E-nose) and Near-Infrared Spectroscopy (FT-NIR) technologies, combined with multivariate statistical techniques, for the rapid discrimination of hazelnuts subjected to different roasting conditions. Moreover, the study examines the ability of NIR to predict several key quality parameters in fresh and processed hazelnuts. Hazelnut samples were collected throughout the entire industrial processing chain, from delivery to roasting. The influence of three different roasting temperatures (140–150-160°C) was evaluated, keeping the roasting time constant at 24 min. Partial Least Squares models were computed to estimate moisture content, total soluble solids, protein content, acidity, and peroxide index through correlation with FT-NIR spectral data. Excellent regression performances were achieved for all quality parameters, except acidity, with correlations ranging between 0.951 and 0.918. Discriminant analysis models, specifically PLS-DA and Cluster Analysis, were used to assess the ability to discriminate hazelnuts subjected to different roasting conditions using FT-NIR and the Electronic Nose as non-destructive tools. Obtained results from these non-destructive techniques, particularly the volatile characterization GC/MS-performed, accurately reflected the differentiation of samples observed through traditional chemical analyses, effectively distinguishing different groups of samples based on roasting temperature. The use of non-destructive tools such as FT-NIR and E-nose during the post-harvest life and processing of hazelnuts offers an excellent solution for monitoring key quality parameters significantly important for the food industry.
https://doi.org/10.1002/fsn3.70095
Advancements and Impacts of Cold Plasma Technology on Dried Nuts and Related Products
In this review, various dried nuts such as almonds, pistachios, peanuts, walnuts, hazelnuts, mixed nuts, and others were subjected to different cold plasma (CP) techniques under varying processing parameters (e.g., voltage, current, frequency, time). The review examines the impact of these treatments on microbial reduction, sensory attributes, and physicochemical properties of the dried nuts. The results showed that CP treatment led to a 1–5 log reduction in microbial species on the surfaces of almond slices, pistachio nuts, peanuts, dried walnut kernels, and mixed nuts. While the peroxide value of the dried nuts remained largely unchanged, a slight increase was observed in peanuts, pistachios, and mixed nut snacks, accompanied by an improvement in antioxidant capacity. The texture of almond slices became harder, while the texture of other dried nuts remained unchanged. There were no significant alterations in the original color, flavor, or appearance of the dried nuts. The CP treatment significantly reduced the levels of toxin-releasing aflatoxins in the dried nuts. The moisture content, which is linked to microbial activity, was significantly decreased. CP also notably enhanced the water-holding capacity in some dried nut products, minimized insect/pest damage, and reduced the allergenicity (Ara h1 and Ara h2) of peanuts and cashew nuts.
https://doi.org/10.1111/jfpe.70080
Uncovering the sensory properties of commercial and experimental clean label almond milks
Almond milk is the largest category of plant-based milk alternatives in the United States, and it is manufactured by suspending ground almond paste in water. Nevertheless, this method limits the amount of almonds that can be added to almond milk, and most almond milks on the market have low protein despite almonds themselves being nutritionally dense. The use of sustainable aqueous and enzyme-assisted aqueous extraction processes offers an alternative method for producing almond milks with enhanced nutritional content. However, it is currently unclear how the sensory properties of such milks compare to those of commercial almond milks. In this study, we conducted a sensory descriptive analysis with 14 trained panelists on 12 commercial almond milk samples and 14 formulated ones (seven aqueous and seven enzyme-assisted aqueous extracted milks). The purpose of this study was to understand how sensorially diverse commercial almond milks are, as well as to determine how aqueous and enzyme-assisted aqueous extracted almond milks compare to commercial methods. We found that formulated samples were significantly different from commercial products, and that all commercial products could be distinguished from each other. Furthermore, commercial milks were more differentiated than were formulated samples. Given the sensory diversity of almond milks on the market, this study suggests that there is potential for introducing new products in the almond milk category. Finally, this study also showed that descriptive analysis can be successfully conducted with two distinct groups of products in the same panel.
https://doi.org/10.1111/1750-3841.70007
Development of a dietary fiber-rich, high-value food ingredient from cashew juice processing for use in plant-based products
Cashew bagasse, often referred to as “cashew meat” in producing regions, is a by-product of cashew apple juice processing. Unfortunately, this biomass is typically discarded as waste by processing industries. However, it possesses valuable compounds like carotenoids and polyphenols that can be extracted. The remaining fiber has unique sensory characteristics in appearance and texture that resemble animal protein, making it a promising raw material for plant-based food formulations. To utilize it as a food ingredient, appropriate treatment is necessary. This study aims to evaluate the effectiveness of pretreatment involving sequential soaking and pressing cycles and various drying processes to enhance its suitability for meat analog products. Cashew bagasse was treated using three fiber-to-water ratios (1:1, 1:1.5, and 1:2 w/w) across five sequential soaking/pressing cycles. The methods assessed included freeze drying, oven drying, and tray drying. Croquette formulations were developed with 30%, 40%, and 50% cashew fiber, along with soy protein, to increase the overall protein content. Physicochemical and sensory evaluations of the treated fibers indicated that acidity, soluble solids, phenolic compounds, and cashew flavor were significantly reduced after the second soaking/pressing cycle, suggesting that fewer cycles may be sufficient. Additionally, the amount of water used did not significantly affect the outcomes. Freeze drying yielded the best drying results. Although the croquette formulations received high sensory acceptance, the one with 50% cashew fiber had a pronounced cashew flavor, which limited its appeal. In conclusion, the bagasse treatment can be optimized to two soaking/pressing cycles, and freeze-drying of the treated fiber provides the best technological results. A cashew fiber content of up to 40% is suitable for use in plant-based croquettes.
https://doi.org/10.1007/s11694-024-03052-1
Oil-in-Water Emulsions Made of Pistachio Oil: Physical and Chemical Properties and Stability
Pistachio nuts are valued for their sensory qualities, nutritional benefits, and health-promoting properties. Pistachio oil has also gained interest for its bioactive compounds, though these are sensitive to processing and environmental stresses. While pistachio-based products are commercially available, little research has addressed the emulsifying properties of crude pistachio oil or its impact on the stability and bioactive profile of oil-in-water (O/W) emulsions. This study evaluated the emulsion-forming abilities of two commercial pistachio oils (PO1, PO2), their physical and oxidative stability during emulsification, and the effects of emulsifier concentration over short-term storage (7 days, 4 °C). O/W emulsions were prepared using 20% (w/w) oil and Tween 20 (0.5% and 1% w/w) in phosphate buffer and homogenized under high pressure. The emulsions were analyzed for particle size, fatty acid profile, antioxidants, and oxidative state. The results revealed differences in fatty acid composition, oxidative stability, and bioactive content between the oils and their emulsions. PO1 showed higher levels of bioactives compared to PO2. Emulsification increased the peroxide value of the oil phase, confirming its pro-oxidant effects. The results of this study demonstrate the potential of pistachio oil to create stable O/W emulsions rich in bioactives, offering new opportunities for healthy emulsified food products.
https://doi.org/10.3390/foods14010060
Evaluation of the Phenolic Components, Fiber Content, Antioxidant Activity, and Prebiotic Capacity of a Shortbread Cookie Fortified with Hazelnut Skin Waste
Food reformulation is a strategy to make healthier foods by using food waste matrices that are still nutritionally valid. A shortbread cookie was reformulated replacing hazelnut skin (HS) of the Tonda Gentile Romana variety (5% and 10%) to refined flour and proportionally decreasing the butter amount. This resulted in significant, two- and five-fold, increases in the antioxidant capacity compared with the control, in the 5% and 10% fortified recipes, respectively. Among the most important antioxidants, gallic acid, catechin, phloridzin, and protocatechuic acid were found. Moreover, here we found, for the first time, that HS from the Romana variety had a high total fiber content (44.13 g/100 g), most of which was insoluble fiber. Therefore, HS 10% addition to the shortbread cookie recipe caused a significant increase in fiber content, making the experimental cookie earn the nutritional claim of "high fiber content". Finally, preliminary evidence demonstrated that 10% HS, in comparison to 5%, following in vitro upper gastrointestinal digestion, conferred significant prebiotic activity in an in vitro culture of L. rhamnosus. Therefore, from the perspective of the circular economy, HS could be a valuable ingredient to increase the antioxidant and prebiotic activities of conventional foods.
https://doi.org/10.3390/foods13233814
Reuse of Almond Skin to Formulate a New Gluten- and Lactose-Free Bakery Product
This work aimed to propose the reuse of processing waste from the Sicilian almond (Prunus amygdalus Batsch.) cultivar Tuono for the formulation of a new functional baked product (muffin) that is gluten- and lactose-free. Muffins were prepared using orange juice, rice flour, extra virgin olive oil, and enriched almond skin (3% and 6% w/w). The chemical-physical parameters, total phenols, and flavonoids (TPC and TFC), as well as the biological properties of the ingredients and muffins, were evaluated. Sensory analyses were also conducted. DPPH, ABTS, β-carotene bleaching, and FRAP tests were applied to measure the antioxidant potential. Muffin extracts were also tested against α-amylase and α-glucosidase enzymes. Muffins enriched with 6% almond skin (M6) showed the highest TPC and TFC with values of 26.96 mg gallic acid equivalent (GAE)/g and 24.12 mg quercetin equivalent (QE)/g, respectively. M6 exerted a promising antioxidant activity as an inhibitor of lipid peroxidation, with an IC50 of 15.44 μg/mL at 30 min incubation. Moreover, muffin M6 showed a promising α-glucosidase inhibitory effect (IC50 of 51.82 μg/mL). Based on the obtained results and supported by sensory analysis, muffins enriched with almond skin should be proposed as a promising example of upcycling for the development of a new functional bakery product.
https://doi.org/10.3390/foods13233796
The Influence of Various Modifications of Hazelnut Shell Flour as Potential Filler in Plywood Technology
This study investigates the potential of utilizing hazelnut shells (HS) as an innovative filler in three-layer plywood technology, addressing the growing need for sustainable, high-performance materials. Traditional plywood production relies on adhesives enhanced with various fillers to improve physical, mechanical, and operational characteristics. This research explores using native, chemically modified, and activated carbon derived from hazelnut shells as fillers in urea-formaldehyde (UF) resin. The produced plywood's mechanical properties, water absorption, and formaldehyde emissions were thoroughly analyzed. Key findings demonstrate that incorporating 10 part by weight (pbw) native hazelnut shell flour significantly enhances the modulus of rupture (MOR) to 138.6 N mm-2 and modulus of elasticity (MOE) to 13,311 N mm-2. Chemically modified hazelnut shell flour achieves optimal results at 5 pbw, while activated carbon from hazelnut shells, even at 1 pbw, markedly improves bonding strength (2.79 N mm-2 referred to 0.81 N mm-2 for reference sample without filler added). Notably, activated carbon effectively reduces formaldehyde emissions (2.72 mg 100 g-1 oven dry panel referred to 3.32 mg 100 g-1 oven dry panel for reference samples with 10 pbw filler) and improves water resistance, indicating better further dimensional stability and lower environmental impact. The study also shows that excessive filler content negatively affects strength parameters, confirming the importance of optimizing filler concentration. These results highlight the potential of hazelnut shells as an eco-friendly alternative filler in plywood production, contributing to waste valorization and environmental sustainability. This study supports the practical application of hazelnut shell fillers, promoting a circular economy and reducing reliance on traditional, less sustainable materials, thus providing a valuable solution for the wood composite industry.
https://doi.org/10.3390/ma17164128
Sensory optimization of gluten-free hazelnut omelette and sugar-modified chestnut pudding: A free choice profiling approach for enhanced traditional recipe formulations
The Mediterranean region is distinguished by its gastronomic diversity and a wide variety of indigenous nut crops. In line with changing global food consumers' preferences, a noteworthy aspect is the increasing demand to the use of local varieties in recipe formulation. The aim of the present study was to incorporate the Terra Fria chestnut (Portugal) and Negreta hazelnut from Reus (Spain) in traditional Mediterranean recipes. The sensory, technofunctional, nutritional, and shelf-life characterization were investigated in hazelnut omelette (gluten and gluten-free) and chestnut pudding (sugar and sugar-free) formulations. Results conducted by trained assessors using the free choice profiling (FCP) showed that hazelnut omelette samples were described as "creamy," "smooth," and "handmade." In addition, the texture obtained with the hazelnut omelette gluten-free version showed the softest textural profile analysis attributes, with lower values for hardness (2.43 ± 0.36 N), adhesiveness (-0.38 ± 0.00 g s) and gumminess (2.12 ± 0.14). Furthermore, the shelf-life studies revealed a more golden color (>14.43 of a* CIELAB coordinate) and a lower moisture content (25.36%-43.59%) in the hazelnut flour formulation, in addition to the enrichment in terms of protein (8.36 g/100 g), fiber, and healthy fats. In the case of chestnut pudding, it was observed that the study parameters did not differ significantly from its sweetened analogue with positive attributes in FCP ("toasted," "fluffy," and "sweet"), positioning it as a viable alternative to sugar in this application. Therefore, both hazelnut flour in hazelnut omelette and oligofructose in chestnut pudding proved to be promising ingredients in the formulation of gluten-free and sugar-free developed products, offering attractive organoleptic and textural characteristics.
https://doi.org/10.1111/1750-3841.17244