Cashew Nutshells: A Promising Filler for 3D Printing Filaments
Cashew nutshells from the northern region of Colombia were prepared to assess their potential use as a filler in polymer matrix filaments for 3D printing. After drying and grinding processes, cashew nutshells were characterized using scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared (ATR-FTIR), and thermogravimetric analyses (TGA). Three different filaments were fabricated from polylactic acid pellets and cashew nutshell particles at 0.5, 1.0, and 2.0 weight percentages using a single-screw extruder. Subsequently, single-filament tensile tests were carried out on them. SEM images showed rough and porous particles composed of an arrangement of cellulose microfibrils embedded in a hemicellulose and lignin matrix, the typical microstructure reported for natural fibers. These characteristics observed in the particles are favorable for improving filler-matrix adhesion in polymer matrix composites. In addition, their low density of 0.337 g/cm3 makes them attractive for lightweight applications. ATR-FTIR spectra exhibited specific functional groups attributed to hemicellulose, cellulose, and lignin, as well as a possible transformation to crystalline cellulose during drying treatment. According to TGA analyses, the thermal stability of cashew nutshell particles is around 320 °C. The three polylactic acid-cashew nutshell particle filaments prepared in this work showed higher tensile strength and elongation at break when compared to polylactic acid filament. The characteristics displayed by these cashew nutshell particles make them a promising filler for 3D printing filaments. https://doi.org/10.3390/polym15224347
Characterization of Artificial Stone Produced with Blast Furnace Dust Waste Incorporated into a Mixture of Epoxy Resin and Cashew Nut Shell Oil
The demand for materials with improved properties and less negative impact on the environment is growing. Artificial stones are examples of these materials produced with up to 90% of particulate material joined by a binder. This article evaluates the physical and mechanical properties of two artificial stones produced with processing steel residue (blast furnace dust waste) and quartz powder. Two binders were used: pure epoxy resin, denoted as ASPB100, or a mixture of 70 wt% epoxy resin with 30 wt% cashew nut shell oil, denoted as ASPB7030. The process took place under vibration, compression (3 MPa/20 min and 90 °C) and vacuum (80 Pa). ASPB100 showed water absorption of 0.07%, while for ASPB7030, it was 0.54%. They were classified as having high mechanical strength associated with bending stress values equal to 32 and 25 MPa, respectively. Stain resistance indicated that both artificial stones had their stains removed with the tested cleaning agents. In this way, the novel artificial stones produced are sustainable alternatives for the application of blast furnace waste and cashew nut shell oil, reducing their negative impacts on the environment. https://doi.org/10.3390/polym15204181
Valorization of walnut green husk (Juglans regia L.) through sequential electrohydrodynamic extraction of pectin and phenolics: Process optimization and multidimensional analysis
This study aimed to optimize the extraction of pectin and phenolics from walnut green husk using the electrohydrodynamic method (EHD) and assess its impact on the chemical structure and properties of pectin. A comparative analysis was conducted with acidified water as the conventional extraction method. The results revealed significant improvements under the optimal EHD conditions (36.8 min, 17.5 kV, 90 °C), leading to a remarkable increase of over 64 % in pectin yield and >20 % in total phenolic content in half the extraction time. Chemical analysis showed that pectin samples contain 1.4-1.7 % ash, 3.6-4.6 % protein, over 90 % carbohydrates, and a galacturonic acid content ranging from 67.7 to 68.2 g/g. Both extraction methods yielded pectin with a high methoxyl degree, comparable thermal stability, and amorphous structure. EHD treatment resulted in reduced molecular weight, degree of esterification, water-holding capacity, and emulsion stability of pectin while enhancing its solubility and emulsion capacity. In summary, EHD treatment significantly improved extraction yield and changed the functionality of pectin, particularly in terms of emulsion activity. This alteration should be considered when utilizing pectin for specific applications. https://doi.org/10.1016/j.ijbiomac.2023.127545
Effects of walnut seed coat polyphenols on walnut protein hydrolysates: Structural alterations, hydrolysis efficiency, and acetylcholinesterase inhibitory capacity
The walnut meal is rich in nutrients such as protein from the kernel and polyphenolic compounds from the seed coat. However, the influences of seed coat polyphenols on walnut protein (WP) hydrolysis remained unclear. In this study, our findings indicated that polyphenols induced alterations in the secondary structure and amino acid composition of WP. These changes resulted in both a hindrance of hydrolysis and an enhancement of acetylcholinesterase (AChE) inhibition. Furthermore, four peptides of 119 identified peptides (LR, SF, FQ, and FR) were synthesized based on higher predicted bioactivity and Vinascores in silico. Among them, FQ showed interaction with amino acid residues in AChE through the formation of four π-π stacking bonds and two hydrogen bonds, resulting in the highest AChE inhibitory capacity. The combination index showed that chlorogenic acid derived from the seed coat and FQ at the molar ratio of 1:4 exhibited synergistic effects of AChE inhibition. https://doi.org/10.1016/j.foodchem.2023.137905
Impact of Modified Atmosphere Packaging Conditions on Quality of Dates: Experimental Study and Predictive Analysis Using Artificial Neural Networks
Dates are highly perishable fruits, and maintaining their quality during storage is crucial. The current study aims to investigate the impact of storage conditions on the quality of dates (Khalas and Sukary cultivars) at the Tamer stage and predict their quality attributes during storage using artificial neural networks (ANN). The studied storage conditions were the modified atmosphere packing (MAP) gases (CO2, O2, and N), packaging materials, storage temperature, and storage time, and the evaluated quality attributes were moisture content, firmness, color parameters (L*, a*, b*, and ∆E), pH, water activity, total soluble solids, and microbial contamination. The findings demonstrated that the storage conditions significantly impacted (p < 0.05) the quality of the two stored date cultivars. The use of MAP with 20% CO2 + 80% N had a high potential to decrease the rate of color transformation and microbial growth of dates stored at 4 °C for both stored date cultivars. The developed ANN models efficiently predicted the quality changes of stored dates closely aligned with observed values under the different storage conditions, as evidenced by low Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE) values. In addition, the reliability of the developed ANN models was further affirmed by the linear regression between predicted and measured values, which closely follow the 1:1 line, with R2 values ranging from 0.766 to 0.980, the ANN models demonstrate accurate estimating of fruit quality attributes. The study's findings contribute to food quality and supply chain management through the identification of optimal storage conditions and predicting the fruit quality during storage under different atmosphere conditions, thereby minimizing food waste and enhancing food safety.
https://doi.org/10.3390/foods12203811
Thermally treated peanut oil bodies as a fat replacer for ice cream: Physicochemical and rheological properties
This study investigates the potential use of peanut oil bodies as a fat replacer in ice cream. We explored the effects of different treatments, fresh (FOB), heated (HOB), and roasted (ROB) peanut oil bodies on ice cream preparation. Heat treatment altered the intrinsic protein profile on the oil bodies' surface, subsequently influencing the ice cream's properties. Notably, heat treatment increases the oil bodies' size and the absolute value of ζ-potential. The rheological analysis provided information about void volumes, indicating easier air incorporation during whipping for ROB (72 to 300 nm) than FOB (107 to 55 nm). ROB ice cream displays a high overrun and a lower melting rate compared to FOB ice cream. Moreover, thermal treatment reduces the beany flavors, n-hexanal, and 2-pentenylfuran. Overall, this study reveals peanut oil bodies as a promising platform for rational design of fat-substituted plant-based ice creams.
https://doi.org/10.1016/j.foodchem.2023.137630
Occurrence of Mycotoxins in Dried Fruits Worldwide, with a Focus on Aflatoxins and Ochratoxin A: A Review.
Dried fruits are popular and nutritious snacks consumed worldwide due to their long shelf life and concentrated nutrient content. However, fruits can be contaminated with various toxigenic fungal species during different stages, including cultivation, harvesting, processing, drying, and storage. Consequently, these products may contain high levels of mycotoxins. This risk is particularly pronounced in developed countries due to the impact of climate change. Several factors contribute to mycotoxin production, including the type of fruit, geographical location, climate conditions, harvest treatments, and storage management practices. The main mycotoxins in dried fruits are aflatoxins (AFs) and ochratoxin A (OTA), which can induce human health problems and economic losses. Mycotoxin contamination can vary significantly depending on the geographic origin of dried fruits (vine fruits, figs, dates, apricots, prunes, and mulberries). The aim of this review was to fill the knowledge gap by consolidating data from various regions to understand the global picture and identify regions with higher contamination risks. By consolidating research from various origins and stages of the supply chain, the review intends to shed light on potential contamination events during pre-harvest, drying, storage, and trading, while also highlighting the effects of storage conditions and climate change on mycotoxin contamination.
https://doi.org/10.3390/toxins15090576
Walnut Kernel Oil and Defatted Extracts Enhance Mesenchymal Stem Cell Stemness and Delay Senescence.
Decreased stemness and increased cellular senescence impair the ability of mesenchymal stem cells (MSCs) to renew themselves, change into different cell types, and contribute to regenerative medicine. There is an urgent need to discover new compounds that can boost MSCs' stemness and delay senescence. Therefore, this study aimed to investigate the impact of walnut kernel oil (WKO) and defatted (WKD) extracts on bone marrow (BM)-MSC stemness and senescence. Premature senescence and inflammation were induced in BM-MSCs using H2O2 and LPS, respectively. Phytochemical constituents of WKO and WKD extracts were detected by HPLC. The stemness (proliferation and migration), senescence-related markers (p53, p21, SIRT1, and AMPK), oxidative stress/antioxidant markers, inflammatory cytokines, and cell cycle of BM-MSCs were measured by MTT assay, qPCR, ELISA, and flow cytometry. WKO and WKD extracts improved rat BM-MSC stemness, as evidenced by (1) increased cell viability, (2) decreased apoptosis (low levels of Bax and caspase3 and high levels of Bcl2), (3) upregulated MMP9 and downregulated TIMP1 expression, and (4) cell cycle arrest in the G0/G1 phase and declined cell number in the S and G2/M phases. Additionally, WKO and WKD extracts reduced rat BM-MSC senescence, as indicated by (1) decreased p53 and p21 expression, (2) upregulated expression and levels of SIRT1 and AMPK, (3) reduced levels of ROS and improved antioxidant activity (higher activity of CAT, SOD, and GPx and upregulated expression of NrF2 and HO-1), and (4) declined levels of TNFα, IL1β, and NF-κB. When compared to the WKO extract, the WKD extract had a greater impact on the induction of stemness and reduction of senescence of BM-MSCs due to its stronger antioxidant activity, which could be attributed to its higher levels of flavonoids and phenolic compounds, as detected by HPLC analysis. WKO and WKD extracts enhance rat BM-MSC stemness and protect them from senescence, suggesting their potential use as enhancers to increase MSCs' therapeutic efficacy.
https://doi.org/10.3390/molecules28176281
A Review on Extracts, Chemical Composition and Product Development of Walnut Diaphragma Juglandis Fructus.
Walnuts are one of the world's most important nut species and are popular for their high nutritional value, but the processing of walnuts produces numerous by-products. Among them, Diaphragma Juglandis Fructus has attracted the attention of researchers due to its complex chemical composition and diverse bioactivities. However, comprehensive reviews of extract activity and mechanistic studies, chemical composition functionality, and product types are scarce. Therefore, the aim of this review is to analyze the extracts, chemical composition, and product development of Diaphragma Juglandis Fructus. Conclusions: For extracts, the biological activities of aqueous and ethanol extracts have been studied more extensively than those of methanol extracts, but almost all of the studies have been based on crude extracts, with fewer explorations of their mechanisms. For chemical composition, the bioactivities of polyphenols and polysaccharides were more intensively studied, while other chemical constituents were at the stage of content determination. For product development, walnuts are mainly used in food and medicine, but the product range is limited. In the future, research on the bioactivity and related mechanisms of Diaphragma Juglandis Fructus can be further expanded to improve its value as a potential natural plant resource applied in multiple industries.
https://doi.org/10.3390/foods12183379
The Antioxidant Activities In Vitro and In Vivo and Extraction Conditions Optimization of Defatted Walnut Kernel Extract.
The objective of this study was to determine the antioxidant activities of defatted walnut kernel extract (DWE) and whole walnut kernel extract (WE) in vitro and in vivo. Three spectrophotometric methods, DPPH, ABTS, and FRAP, were used in in vitro experiments, and mice were used in in vivo experiments. In addition, response surface methodology (RSM) was used to optimize reflux-assisted ethanol extraction of DWE for maximum antioxidant activity and total phenolic content. The results of in vitro experiments showed that both extracts showed antioxidant activity; however, the antioxidant activity of DWE was higher than that of WE. Both extracts improved the mice's oxidative damage status in in vivo studies. An ethanol concentration of 58%, an extraction temperature of 48 °C, and an extraction time of 77 min were the ideal parameters for reflux-assisted ethanol extraction of DWE. The results may provide useful information for further applications of defatted walnut kernels and the development of functional foods.
https://doi.org/10.3390/foods12183417