Search Results (44)

Avocado is a rich source of numerous nutrients, such as micro- and macroelements, essential unsaturated fatty acids, and vitamins essential for the correct functioning of the body. Consequently, its consumption has significantly increased in recent years. The primary edible part of the fruit is the flesh, while the seed is still considered biowaste. Currently, various methods for utilization of this biowaste are being explored, prompting the authors of this work to investigate the catalytic properties of ground avocado seeds. Dried, ground avocado seeds were used as the catalyst in the environmentally friendly oxidation of limonene with oxygen. The process was carried out in mild conditions, without the use of any solvent and at atmospheric pressure. The studies examined the influence of temperature (70–110 °C), the amount of the catalyst (0.5–5.0 wt%), and the reaction time (15–360 min). The analyses of the post-reaction mixtures were performed using the gas chromatography method (GC). The maximum value of the conversion of limonene obtained during the tests was 36 mol%. The main products of this process were as follows: 1,2-epoxylimonene, carveol, and perillyl alcohol. Also, the following compounds were determined in the post-reaction mixtures: carvone and 1,2-epoxylimonene diol. The studied process is interesting, taking into account both the management of waste in the form of avocado seeds and possible wide applications of limonene transformation products in medicine, cosmetics and the food industry. Given that limonene is now increasingly being extracted from waste orange peels, this is also a good way to manage the future naturally derived limonene and reduce the amount of waste orange peels. The presented studies fit perfectly with the goals of sustainable development and circular economy and may be the basis for the future development of “green technology” for obtaining value-added oxygenated derivatives of limonene. These studies show the use of waste biomass in the form of avocado seeds to obtain a green catalyst. In this context, our research presents an effective way of waste valorization. Full article

The increasing demand for poultry products has led to significant by-products, with chicken bones being a rich source of proteins and minerals. The protease hydrolysis of chicken bones has emerged as a key method for extracting chicken bone protein. The objective of this study was to optimize enzyme combinations and hydrolysis reaction conditions to enhance both the nutritional value and quality of the product. Through univariate experiments and response surface methodology, the optimal enzymatic hydrolysis conditions were determined as follows: 55 °C, 1.5 h, and composite enzymes comprising papain (2.53%), bromelain (4%), and flavorzyme (4%) (w/w). The peptide content of the hydrolysis product obtained with the composite enzyme reached 336.78 mg/g, with small molecular peptides (<500 Da) accounting for 95% of the composite enzyme hydrolysis product. These small molecular peptides are more readily absorbed by the human body. Additionally, the free amino acids significantly increased, particularly those more easily absorbed by the human body such as glutamic, glycine, and aspartic. Moreover, there was a notable increase in the volatile flavor compounds including aldehydes and alcohols, which enhanced the flavor profile by producing fatty or mushroom-like aromas. This method enhances protein recovery and sample quality, converting chicken bone waste into valuable ingredients, contributing to sustainable food practices and innovative consumables for both pet and human consumption. Full article

Annatto (Bixa orellana L.) is cultivated primarily for the extraction of bixin, a natural dye with substantial industrial importance, resulting in the generation of large quantities of residues that remain underutilized. This study provides the first in-depth characterization of annatto byproducts derived through molecular distillation, highlighting their untapped potential for sustainable innovation. Employing state-of-the-art techniques—HS-SPME-GC-MS for volatile compounds and UPLC-MS/QTOF for non-volatile ones—the research identified a remarkable array of bioactive constituents. Over thirty pharmacologically significant compounds were unveiled, many appearing for the first time in annatto byproducts. Notable discoveries include diterpenoid alcohols, oleamide, δ-tocotrienol, n-alkanes, fatty acid methyl esters, and springene among the volatiles. Among the non-volatiles, groundbreaking identifications such as dihydroactinidiolide, dihydrochalcone, 3-phenyl propiofenone, novel tetracosan amides, halisphingosine A, kauranetriols, and phytoene derivatives redefine the chemical profile of this residue. Further amplifying the value of these findings, the study successfully transformed these byproducts into innovative antioxidant packaging materials, demonstrating their high potential for food preservation and sustainable applications. The packaging films, developed from samples devoid of vegetable oil, exhibited robust antioxidant properties, offering a compelling solution to extend shelf life and reduce spoilage. This work underscores the importance of revalorizing agricultural residues like annatto byproducts, turning waste into high-value resources that align with the principles of the circular economy. Full article

Background: Humans cannot avoid plastic exposure due to its ubiquitous presence in the natural environment. The waste generated is poorly biodegradable and exists in the form of MPs, which can enter the human body primarily through the digestive tract, respiratory tract, or damaged skin and accumulate in various tissues by crossing biological membrane barriers. There is an increasing amount of research on the health effects of MPs. Most literature reports focus on the impact of plastics on the respiratory, digestive, reproductive, hormonal, nervous, and immune systems, as well as the metabolic effects of MPs accumulation leading to epidemics of obesity, diabetes, hypertension, and non-alcoholic fatty liver disease. MPs, as xenobiotics, undergo ADMET processes in the body, i.e., absorption, distribution, metabolism, and excretion, which are not fully understood. Of particular concern are the carcinogenic chemicals added to plastics during manufacturing or adsorbed from the environment, such as chlorinated paraffins, phthalates, phenols, and bisphenols, which can be released when absorbed by the body. The continuous increase in NMP exposure has accelerated during the SARS-CoV-2 pandemic when there was a need to use single-use plastic products in daily life. Therefore, there is an urgent need to diagnose problems related to the health effects of MP exposure and detection. Methods: We collected eligible publications mainly from PubMed published between 2017 and 2024. Results: In this review, we summarize the current knowledge on potential sources and routes of exposure, translocation pathways, identification methods, and carcinogenic potential confirmed by in vitro and in vivo studies. Additionally, we discuss the limitations of studies such as contamination during sample preparation and instrumental limitations constraints affecting imaging quality and MPs detection sensitivity. Conclusions: The assessment of MP content in samples should be performed according to the appropriate procedure and analytical technique to ensure Quality and Control (QA/QC). It was confirmed that MPs can be absorbed and accumulated in distant tissues, leading to an inflammatory response and initiation of signaling pathways responsible for malignant transformation. Full article

Throughout the decades, the production, transport, and use of fossil fuels have led to numerous environmental concerns. Crude oil has caused catastrophic accidents after its spillage into the aqueous environment and accumulation on coastal sediments. To tackle this problem in a sustainable manner, researchers have used alternative remediation agents to extract these crude oil spills from the sediments. In this study, the biodiesels fatty acid methyl, ethyl, and butyl esters (FAME, FAEE, and FABE, respectively) were synthesized via transesterification reaction from waste cooking oil and corresponding alcohol in the presence of a catalyst, potassium hydroxide, and used as remediation agents for crude oil extraction. The influence of different experimental conditions on the crude-oil removal efficiency was studied (time of 1, 2, or 4 h; mass ratio of biodiesel to crude oil of 0.5:1, 1:1, or 2:1), with a simulation of coastal effects using a shaker. UV/Vis spectrophotometry was used to determine crude-oil separation efficiency based on the correlation of the residual crude-oil mass fraction and corresponding absorbance. The results show that FAME and FAEE were most effective in the removal of crude oil from sand (removing 88–89%), while FAEE and FABE extracted the most crude oil from gravel (removing 74–77%). Full article

Hydrogen is a well-known clean energy carrier with a high energetic yield. Its versatility allows it to be produced in diverse ways, including biologically. Specifically, dark fermentation takes advantage of organic wastes, such as agro-industrial residues, to obtain hydrogen. One of these harmful wastes that is poorly discharged into streams is sugarcane bagasse pentose liquor (SBPL). The present study aimed to investigate hydrogen generation from SBPL fermentation in batch reactors by applying different food/microorganism (2–10 F/M) and carbon/nitrogen (10–200 C/N) ratios under mesophilic and thermophilic conditions. Biohydrogen was produced in all pentose liquor experiments along with other soluble microbial products (SMPs): volatile fatty acids (VFAs) (at least 1.38 g L⁻¹ and 1.84 g L⁻¹ by the average of C/N and F/M conditions, respectively) and alcohols (at least 0.67 g L⁻¹ and 0.325 g L⁻¹ by the average of C/N and F/M conditions, respectively). Thermophilic pentose liquor reactors (t-PLRs) showed the highest H₂ production (H₂ maximum: 1.9 ± 0.06 L in 100 C/N) and hydrogen yield (HY) (1.9 ± 0.54 moles of H₂ moles of substrate⁻¹ in 2 F/M) when compared to mesophilic ones (m-PLRs). The main VFA produced was acetate (>0.85 g L⁻¹, considering the average of both nutritional conditions), especially through the butyrate pathway, which was the most common metabolic route of experimental essays. Considering the level of acid dilution used in the pretreatment of bagasse (H₂SO₄ (1%), 1.1 atm, 120 °C, 60 min), it is unlikely that toxic compounds such as furan derivatives, phenol-like substances (neither was measured), and acetate (<1.0 g L⁻¹) hinder the H₂ production in the pentose liquor reactors (PLRs). Sugarcane bagasse pentose liquor fermentation may become a suitable gateway to convert a highly polluting waste into a renewable feedstock through valuable hydrogen production. Full article

Single-cell oils (SCOs) offer a promising alternative to conventional biodiesel feedstocks. The main objective of this work was to obtain SCOs suitable for biodiesel production from the oleaginous yeast Rhodotorula glutinis R4 using sugarcane vinasse from a local sugar-derived alcohol industry as the substrate. Additionally, crude glycerol from the local biodiesel industry was evaluated as a low-cost carbon source to replace expensive glucose and as a strategy for integrating the bioethanol and biodiesel industries for the valorization of both agro-industrial wastes. R4 achieved a high lipid accumulation of 88% and 60% (w/w) in vinasse-based culture media, containing 10% and 25% vinasse with glucose (40 g L⁻¹), respectively. When glucose was replaced with crude glycerol, R4 showed remarkable lipid accumulation (40%) and growth (12.58 g L⁻¹). The fatty acids profile of SCOs showed a prevalence of oleic acid (C18:1), making them suitable for biodiesel synthesis. Biodiesel derived from R4 oils exhibits favorable characteristics, including a high cetane number (CN = 55) and high oxidative stability (OS = 13 h), meeting international biodiesel standards (ASTMD6751 and EN14214) and ensuring its compatibility with diesel engines. R. glutinis R4 produces SCOs from vinasse and crude glycerol, contributing to the circular economy for sustainable biodiesel production. Full article

Liver fibrosis is a condition characterized by the excessive buildup of scar tissue in the liver. This scarring occurs as a result of chronic liver damage, often caused by conditions such as hepatitis, alcohol abuse, certain metabolic disorders, genetic abnormalities, autoimmunity, and noninfectious diseases such as fatty liver which leads to liver fibrosis. Nanoparticles have gained attention in recent years as potential therapeutic agents for liver fibrosis. They offer unique advantages due to their small size, large surface area, and ability to carry drugs or target specific cells or tissues. Studies have suggested that nanoemulsions may enhance drug delivery systems, enabling targeted drug delivery to specific sites in the liver and improving therapeutic outcomes. In this study, we explore the protective and therapeutic values with phytochemical profiling of the used agro-wastes decaffeinated palm date seeds (Phoenix dactylifera L., PSC) coffee and caffeinated Arabic coffee seeds (Coffea arabica L.; ACS). Both ACS and PSC extracts were converted into nanoemulsion (NE) forms using the oleic acid/Tween 80 system, which was recruited for the purpose of treating a rat model with liver fibrosis. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were used to record the sizes, morphologies, hydrodynamic diameters, and ζ-potentials of the prepared NE-ACSE and NE-PSCE. Accordingly, the NE-ACSE and NE-PSCE imaged via TEM and their ζ-potentials were recorded at 20.7, 23.3 nm and −41.4, −28.0 mV, respectively. The antioxidant properties were determined with a DPPH scavenging assay. The synthesized NE-PSCE and NE-ACSE were employed to treat a rat model with CCl₄-induced liver fibrosis, to estimate the role of each emulsion-based extract in the treatment of liver fibrosis through recording inflammatory parameters, liver functions, antioxidant enzymes, and histopathological analysis results. The nanoemulsion forms of both ACSE and PSCE provided significant increases in antioxidant enzymes, reducing inflammatory parameters, compared to other groups, where liver functions were decreased with values close to those of the control group. In conclusion, both nanoemulsions, ACSE and PSCE, provided a new avenue as therapeutic approaches for liver diseases, and further studies are encouraged to obtain maximum efficiency of treatment via the combination of both extracts. Full article

In 2021, global plastics production was 390.7 Mt; in 2022, it was 400.3 Mt, showing an increase of 2.4%, and this rising tendency will increase yearly. Of this data, less than 2% correspond to bio-based plastics. Currently, polymers, including elastomers, are non-recyclable and come from non-renewable sources. Additionally, most elastomers are thermosets, making them complex to recycle and reuse. It takes hundreds to thousands of years to decompose or biodegrade, contributing to plastic waste accumulation, nano and microplastic formation, and environmental pollution. Due to this, the synthesis of elastomers from natural and renewable resources has attracted the attention of researchers and industries. In this review paper, new methods and strategies are proposed for the preparation of bio-based elastomers. The main goals are the advances and improvements in the synthesis, properties, and applications of bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers, and an approach to their circular economy and sustainability. Olefin metathesis is proposed as a novel and sustainable method for the synthesis of bio-based elastomers, which allows for the depolymerization or degradation of rubbers with the use of essential oils, terpenes, fatty acids, and fatty alcohols from natural resources such as chain transfer agents (CTA) or donors of the terminal groups in the main chain, which allow for control of the molecular weights and functional groups, obtaining new compounds, oligomers, and bio-based elastomers with an added value for the application of new polymers and materials. This tendency contributes to the development of bio-based elastomers that can reduce carbon emissions, avoid cross-contamination from fossil fuels, and obtain a greener material with biodegradable and/or compostable behavior. Full article

Biodiesel is a widely recognized and favored liquid biofuel, primarily attributed to its biodegradability and non-toxicity. However, the development of biodiesel is hindered by its high production costs. Here, we developed a method that combines glycerol esterification and transesterification reaction catalyzed using nano-hydrated CaO for the green production of biodiesel from high acid value oil. Waste eggshell was chosen as the calcium source to examine the effect of hydration temperature and duration. The catalysts were optimized using a synthesis process involving under calcination for 3 h at 875 °C, followed by hydration at 60 °C for 6 h and subsequent dehydration at 725 °C. The catalyst loading, alcohol-to-oil mass ratio, reaction temperature, and duration were optimized to 2.5 wt%, 35%, 60 °C, and 2 h, respectively. Under the optimized conditions, the yield of fatty acid methyl ester reached 94.44%. The catalyst was successfully reused eight cycles while maintaining a yield of fatty acid methyl ester at 80.52%. In addition, a comprehensive overview was summarized to compare the catalyst preparation methods, reaction conditions, biodiesel yield, and reusability in the production of biodiesel using eggshell-derived CaO. Full article

This study propounds a sustainable alternative to petroleum-based polyurethane (PU) foams, aiming to curtail this nonrenewable resource’s continued and uncontrolled use. Coconut fatty acid distillate (CFAD) and crude glycerol (CG), both wastes generated from vegetable oil processes, were utilized for bio-based polyol production for rigid PU foam application. The raw materials were subjected to catalyzed glycerolysis with alkaline-alcohol neutralization and bleaching. The resulting polyol possessed properties suitable for rigid foam application, with an average OH number of 215 mg KOH/g, an acid number of 7.2983 mg KOH/g, and a Gardner color value of 18. The polyol was used to prepare rigid PU foam, and its properties were determined using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis/derivative thermogravimetric (TGA/DTA), and universal testing machine (UTM). Additionally, the cell foam morphology was investigated by scanning electron microscope (SEM), in which most of its structure revealed an open-celled network and quantified at 92.71% open-cell content using pycnometric testing. The PU foam thermal and mechanical analyses results showed an average compressive strength of 210.43 kPa, a thermal conductivity of 32.10 mW·m⁻¹K⁻¹, and a density of 44.65 kg·m⁻³. These properties showed its applicability as a type I structural sandwich panel core material, thus demonstrating the potential use of CFAD and CG in commercial polyol and PU foam production. Full article

The purpose of this study is the effective utilization of fisheries waste, squid liver, as a raw material of biodiesel. To obtain biodiesel from squid liver, extracted fatty acids are esterified with methyl alcohol. As the product of the esterification contains many by-products, the target product, fatty acid methyl ester of squid liver (SFAME), must be recovered from the products. SFAME is divided into three groups, which are saturated (SF), monounsaturated (MF), and polyunsaturated (PF) fatty acid methyl esters (FAMEs), based on the number of double bonds. In this study, the recovery of SFAME from the product of esterification through adsorption (i.e., dry washing) was investigated. Especially, the effect of solvents, toluene, and methyl alcohol on the recovery efficiency of SFAME using silica gel as an adsorbent was the focus. The competitive adsorption model successfully explained the present adsorption system, and the equilibrium adsorption constants and the saturated adsorption density could be determined by the model analysis. The equilibrium adsorption constant of PF was the largest among the SFAME (PF > MF > SF), and this order could correspond to the values of their dielectric constants. Methanol greatly affected the adsorption behavior of SFAME due to the fact of its hydrophilicity. Full article

The effect of temperature was studied on the synthesis of fatty acid alkyl esters by means of transesterification of waste beef tallow using ethanol and, iso-butanol and 1-butanol at supercritical conditions. These alcohols are proposed for the synthesis of biodiesel in order to improve the cold flow properties of alkyl esters. Alcohol–beef tallow mixtures were fed to a high-pressure high-temperature autoclave at a constant molar ratio of 45:1. Reactions were carried out in the ranges of 310–390 °C and 310–420 °C for ethanol and iso-butanol, respectively; meanwhile, synthesis using 1-butanol was assessed only at 360 °C. After separation of fatty acid alkyl esters, these samples were characterized by nuclear magnetic resonance (NMR) and gas chromatography coupled to mass spectrometry (GC-MS) to quantify yields, chemical composition, and molecular weight. Results indicated that yields enhanced as temperature increased; the maximum yields for fatty acid ethyl esters (FAEEs) were attained at 360 °C, and for fatty acid butyl esters (FABEs) were achieved at 375 °C; beyond these conditions, the alkyl ester yields reached equilibrium. Concerning the physicochemical properties of biodiesel, the predicted cetane number and cloud point were enhanced compared to those of fatty acid methyl esters. Full article

The activity of MOF-5-based solids has been exploited in the simultaneous transesterification and esterification of acid vegetable oils. For this purpose, three different types of MOF-5 have been synthesized and characterized, and then tested in the above-mentioned reactions. It has been demonstrated that the “regular MOF-5” was a suitable catalyst for biodiesel synthesis from waste oil also, rich in FFA (Free Fatty Acids). Moreover, to identify the true structure that acts in the reactions and possible structural modifications due to the presence of alcohols, proper studies have been performed. The results have evidenced a distortion of the regular structure of MOF-5 due to the breakage of some zinc bonds between the cluster and organic framework. Full article

Coffee is a popular and widely consumed beverage worldwide, with epidemiological studies showing reduced risk of cardiovascular disease, cancers and non-alcoholic fatty liver disease. However, few studies have investigated the health effects of the post-brewing coffee product, spent coffee grounds (SCG), from either hot- or cold-brew coffee. SCG from hot-brew coffee improved metabolic parameters in rats with diet-induced metabolic syndrome and improved gut microbiome in these rats and in humans; further, SCG reduced energy consumption in humans. SCG contains similar bioactive compounds as the beverage including caffeine, chlorogenic acids, trigonelline, polyphenols and melanoidins, with established health benefits and safety for human consumption. Further, SCG utilisation could reduce the estimated 6–8 million tonnes of waste each year worldwide from production of coffee as a beverage. In this article, we explore SCG as a major by-product of coffee production and consumption, together with the potential economic impacts of health and non-health applications of SCG. The known bioactive compounds present in hot- and cold-brew coffee and SCG show potential effects in cardiovascular disease, cancer, liver disease and metabolic disorders. Based on these potential health benefits of SCG, it is expected that foods including SCG may moderate chronic human disease while reducing the environmental impact of waste otherwise dumped in landfill. Full article