Waste Extract Research Articles

Studies on unlocking the potential of onion waste extracts in edible coating for shelf-life extension of strawberry

Studies on unlocking the potential of onion waste extracts in edible coating for shelf-life extension of strawberry

Generation of compressed air by overdriven free-displacer thermocompressors – Experimental investigation of a three-stage cascade

Due to their straightforward design and advantageous operational characteristics, cascaded arrangements of overdriven free-displacer thermocompressors may provide a simple, expedient and cost-effective solution to reduce the high primary energy requirements for compressed air generation, which is a common challenge in industry. Following first experiments with a single-stage prototype, this contribution presents the first experimental realization of a three-stage cascade so that the overall concept has now been demonstrated to be fully operational for the first time. In particular, the predicted self-control capabilities of a stage located within the cascade and thus without any preset inlet or outlet pressure could be proven, whereas this had been impossible with the single-stage prototype before. Stable operation with all stages running is possible at total pressure ratios ranging from a practical maximum near 2.1 down to approximately 1.36. At even lower values, the pressure ratio of the first stage undercuts an analytically predicted lower stability limit and eventually stops, whereas the power density of the remaining stages is increased. To exploit the potential for improvement identified during the single-stage experiments, the design of the new stages is based on the first prototype, but has been optimized by a similarity-based scaling procedure and design evolution, resulting in a significant increase in power density from 7.1 W to 12.5 W per liter of displacement. To further demonstrate the capability of such a cascade to extract waste heat from a hot stream, the heater temperatures of the stages were successively reduced along the cascade by an adequate control, thus emulating a finite heat capacity rate of the stream. Although the exergy transferred to the compressed air flow is reduced in this case, the overall performance is not adversely affected. The combination of the models and the scaling approach, which have now been demonstrated experimentally, provides a comprehensive toolbox for the future development of a series machine.

Evaluation of the antibacterial activity of pineapple (Ananas comosus) (L.) Merr. industrial waste against common fish and shellfish pathogens

Disposal of industrial pineapple (Ananas comosus) wastes is a pressing environmental issue due to pollution risks when accumulated in large quantities. These wastes are susceptible to microbial spoilage, posing serious environmental and health concerns. Therefore, exploring their conversion into valuable products is crucial for effective waste management. In this study, we assessed the antibiotic properties of pineapple processing wastes against prevalent fish pathogens in aquaculture. The wastes underwent various drying methods: sun-drying (SD), oven-drying (OD), and mechanical dehydration (DH). Ethanol extraction was used to isolate bioactive compounds, which were then tested for antibacterial activity at a concentration of 1000 mg/ml using the Agar Well Diffusion technique and Zone of Inhibition (ZOI) assay. Minimum Inhibitory Concentration (MIC) values were determined across six concentrations: 31.25 mg/ml, 62.50 mg/ml, 125 mg/ml, 250 mg/ml, 500 mg/ml, and 1000 mg/ml. Results indicated that all extracts from different drying processes effectively inhibited all tested aquaculture pathogens. DH extracts showed the highest antibacterial activity against Vibrio harveyi and Vibrio parahaemolyticus, with ZOI of 24.67 + 1.25 mm and 21.67 + 0.47 mm, respectively, and a consistent MIC of 250 mg/ml across all pathogens. SD extracts displayed a MIC of 125 mg/ml against Streptococcus agalactiae, while OD extracts showed a MIC of 1000 mg/ml against Edwardsiella tarda, Aeromonas veronii, and S. agalactiae, and 250 mg/ml against both Vibrio species. Comparative analysis with oxytetracycline did not reveal significant differences. These findings suggest that pineapple waste extracts have potential as natural antibacterial agents against common aquaculture pathogens, offering an eco-friendly alternative to commercial antibiotics.

Synthesis of Calcium Carbonate from Orange Peel Waste Extract: A Mechanistic Investigation

The present work reports the mechanism and synthesis of calcium carbonate (CaCO3) formation from orange peel, which is one of the most common agriculture waste generated throughout the globe. The zest of oranges was co-distilled with distilled water to separate the essential oil content. Further, the residue was washed twice with distilled water to get the desired extract. For the green synthesis of CaCO3, a saturated solution of calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) was mixed thoroughly with orange peel extract in the 1:3 proportion. This solution was kept on magnetic stirrer while maintaining temperature at 85˚C, heated at 100˚C for 13 h which was further annealed at 300˚C, 500˚C and 700˚C. X-ray diffraction (XRD) shows the presence of calcite phase corresponding to CaCO3. Fourier transform infrared spectra (FTIR) exhibits the bands corresponding to Ca-O, C-O and vibrations of CO3-2 bonds whereas UV–Visible spectroscopy shows the optical behavior of CaCO3. The qualitative analysis of orange peel extract as well as the black-brown gel formed as a result of sol–gel synthesis method was examined using Gas Chromatography & Mass Spectrometry (GCMS). It revealed the presence of acidic groups (2,3-butanediol & 1,4-benzenediol) which led to the development of a mechanism, governing the formation of CaCO3.

Novel avenue of carotenoids & omega-3 rich carrot waste extract in innovative table spread: optimization (based on texture and sensory) and characterization

Carrot waste is a rich source of pro-vitamin A, β-carotene, recognized for its immunomodulatory and health-promoting properties. The present study was aimed at formulating an innovative table spread (ITS) enriched with concentrated carotenoid extract derived from carrot pomace. Prior extraction of carotenoids in flaxseed oil was optimized resulting in extract (CE) rich in carotenoids (82.66 µg/g) and alpha-linolenic acid (ALA). The effects of three ingredients i.e. CE, tri-sodium citrate (TC), and common salt (CS) on ITS formulated using 33 factorial experiment (27 treatment combinations) were determined employing three-way ANOVA of Proc GLM method of SAS 9.3 for its textural and sensory acceptability. The optimized formulation contained 15% CE, 1.0% CS and 0.3% TC. ITS displayed medium (≈51% fat) internal phase emulsion (confirmed via fluorescence microscopy) stabilized (-56.867 mV ± 0.850 zeta potential) by whey protein concentrate and possessed high thermal stability (studied through thermogravimetric analysis). The control table spread (CTS) was prepared using all ingredients except CE replaced with flaxseed oil. ITS showed significantly (p < 0.05) higher carotenoid, antioxidant (ABTS, DPPH and FRAP), yellowness index and b* value than CTS; while non-significant (p > 0.05) difference existed for proximate composition and acidity. ITS turned out to be a naturally colored functional product and excellent source of carotenoids (24.276 μg/g ± 0.076) and ALA (13.816 g/ 100 g fat).

Residues from beneficiation of granite in porcelain stoneware: Effects on technological properties

Granite extraction waste represents an interesting alternative material for porcelain stoneware production, but information on its influence presents several gaps. For this reason, two different wastes were selected: a coarser iron-rich material from magnetic separation and a finer one from conveyance and abatement systems. Both were physically and chemically characterized. Batches were formulated by partial substitution of feldspar and technological behaviour of bodies was assessed by simulating the industrial manufacture at laboratory scale. Tiles were shaped by uniaxial pressure and fired by fast firing in electric roller kiln. The effect of waste addition was evaluated during the whole production process. Fired samples were characterized in terms of technological properties, mineralogical composition and microstructure evolution. The formulation optimization reduces firing temperature getting commercial technological constraints. A further increase of finer waste content affects compaction and mechanical strength. The presence of micaceous particles after the firing process may act as cracks initiation.

Mycorrhizal symbiosis and natural dye waste organic fertilizer: Enhancing growth and yield in indigofera tinctoria

Background: Indigofera tinctoria, commonly known as true indigo, is a plant widely used in the textile industry for its natural indigo dye, which produces a rich blue color for fabrics. Indigofera tinctoria, known for its natural bluish-purple dye, generates 10% dye and 90% waste during extraction, requiring effective waste management. This study aimed to optimize organic fertilizer and mycorrhiza doses from I. tinctoria waste for enhancing soil fertility in arid regions. Methods: The study was conducted from May to December 2020 in Puron Village, Bulu District, Sukoharjo Regency. A factorial Completely Randomized Block Design (CRBD) with 2 factors was employed. The first factor consisted of 5 levels of I. tinctoria organic fertilizer treatments: 0, 100, 200, 300, and 400 g per plant. The second factor included 3 levels of mycorrhiza treatments: 0, 10, and 20 g per plant. Variables observed included mycorrhizal infection on roots, plant growth rate, and yield (fresh leaf and shoot weight of I. tinctoria). Data analysis utilized ANOVA at a 5% significance level followed by Duncan Multiple Range Test (DMRT). Results: The results indicated that organic fertilizer from natural dye waste at a dosage of 200 g per plant increased the percentage of mycorrhizal-infected roots and boosted shoot weight by 63.27% at 8 weeks after planting (WAP). Mycorrhiza at 10 g per plant increased mycorrhizal infection percentage and enhanced shoot weight by 45.98% at 4 WAP. The combination of I. tinctoria extraction waste organic fertilizer at 200 g per plant and mycorrhiza at 10 g per plantshowed interaction, significantly increasing the growth of root nodules of Indigofera tinctoria by 84.04% at 12 WAP. Conclusion: The integration of organic fertilizer derived from indigo dye waste and mycorrhiza presents a promising strategy for enhancing I. tinctoria growth and productivity. Novelty/Originality of this Study: This study is distinctive in its demonstration of the effective use of I. tinctoria extraction waste as an organic fertilizer, aligning with zero-waste principles and contributing to improvements in plant growth and soil fertility. Furthermore, it investigates the synergistic effects of mycorrhizal associations on enhancing nutrient absorption and overall productivity of I. tinctoria, an aspect that has not been thoroughly explored in prior research.

Evaluation of six phenolic compounds content and antifungal activity against wood-decay fungi of tobacco waste extracts obtained by ultrasound-assisted extraction

The tobacco industry produces substantial amounts of biomass waste that contains bioactive substances that may serve as renewable energy sources. This study reports an efficient and environmentally friendly method for the simultaneous extraction of gallic, protocatechuic, vanillic, chlorogenic, caffeic, and ferulic acids from tobacco waste. The ultrasound-assisted extraction (UAE) parameters were optimized using one-factor-at-a-time method and response surface methodology (RSM), in combination with Box-Behnken design (BBD). The optimal extraction conditions were an extraction temperature of 62 °C, a solvent-to-solid ratio of 19 mL/g, an ethanol-to-water ratio of 62%, and an extraction time of 38 min. The composition and content of phenolic compounds extracted using this optimized method were identified by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS). The extraction yield and antifungal activity against wood-decay fungi using the extracts obtained with the UAE method were much higher than those obtained using maceration and heat reflux extraction. The results demonstrated that the UAE method extracted six phenolic compounds in tobacco waste, which could then be quantitatively analyzed. This study provides a green and efficient method for extracting active ingredients from waste tobacco and offers a new perspective for utilizing tobacco waste as an antifungal agent against wood-decay fungi.

Green synthesis of CuO nanoparticles via Tulsi (Ocimum Sanctum) leaf extract for efficient adsorptive removal of doxycycline hydrochloride from aqueous solution

Due to significant consumption and improper disposal, the increase in emerging broad-spectrum antibacterial pharmaceutical contaminants in water bodies leds to degradation of quality of water resources and aquatic life, causes water availability issues. Doxycycline hydrochloride belongs to the tetracycline antibiotic class of drug, exhibits a significant persistence of toxicity in the aquatic environment. In the present study, eco-friendly CuO nanoparticles were biosynthesized using ocimum sanctum leaf waste extract and an investigation was carried out for the efficient adsorptive removal of doxycycline hydrochloride from pharmaceutical waste with harmful impacts on the environment. UV–visible spectra, XRD, FTIR, EDX, BET, HRTEM and FESEM analysis were used to characterize surface modification of the biosynthesized nanoparticles. Drug concentration, contact time, pH, temperature and adsorbent dosage were among the main adsorption parameters that were examined in order to optimize the most effective removal results. Maximum adsorption capacity of 8.56 mg/g was achieved at optimum process parameter; 100 mg/L, 170 min., pH 6 at 298 K. Moreover, various isotherm models were examined in order to accurately describe the adsorption equilibrium experimental results. Although, the thermodynamic data and kinetic study showed that the sorption process was spontaneous and endothermic, followed second order kinetic model. The outcomes showed that green synthesized CuO nanoadsorbent can be effectively employed for the removal of antibiotic medications from actual wastewater.

The comprehensive utilization of mass and heat of hot blast furnace slag and coordinated disposal of chromium-containing sludge to prepare glass-ceramic

Currently in steel enterprises, the mass and heat of hot blast furnace slag (BFS) are not fully recovered, and the produced chrome-containing sludge (CCS) poses a significant threat to the ecological environment. In this work, CCS together with other ingredients is added into hot BFS to produce high value-added glass-ceramic (GC), after the mixed molten slag is cooled down. The obtained GC shows excellent physical and chemical properties (bulk density: 2.76 g cm−3, water absorption: 0.059 %, compressive strength: 78 MPa, Vickers hardness: 7.54 GPa, acid resistance: 98.63 %, alkali resistance: 99.84 %, thermal conductivity: 1.049 W m−1 °C−1, and thermal expansivity: 6.56 × 10−6 m m−1 °C−1). These excellent physical and chemical properties render the as-prepared GC a high value-added building material. In addition, the leaching concentrations of total Cr element and Cr(VI) in the as-prepared GC are 1.6 mg L−1 and 1.03 mg L−1, respectively, which are below the standard threshold for hazardous waste extraction toxicity. Compared with the traditional sintering method, the sensible heat of the hot BFS can be used as the thermal source in the molten slag cooling method, which can save a lot of energy. The use of hot BFS and CCS to produce high value-added GC not only fully utilizes the mass and heat of hot BFS but also fixes the Cr element in the CCS within the crystalline phase of GC, thereby eliminating the pollution of CCS to the environment.

Valorization of citrus peel industrial wastes for facile extraction of extractives, pectin, and cellulose nanocrystals through ultrasonication: An in-depth investigation

In this work we developed an eco-friendly valorisation of Citrus wastes (CWs), through a solvent-assisted ultrasonication extraction technique, thus having access to a wide range of bio-active compounds and polysaccharides, extremely useful in different industrial sectors (food, cosmetics, nutraceutical). Water-based low-amplitude ultrasonication was examined as a potential method for pectin extraction as well as polar and non-polar citrus extractives (CEs), among which hesperidin and triglycerides of 18 carbon fatty acids were found to be the most representative ones. In addition, citric acid:glycerol (1:4)-based deep eutectic solvent (DES) in combination with ultrasonic extraction was utilized to extract microcellulose (CMC), from which stable cellulose nanocrystals (CNCs) with glycerol-assisted high amplitude ultrasonication were obtained. The physical and chemical properties of the extracted polysaccharides (pectin, micro and nanocellulose) were analysed through DLS, ζ-potential, XRD, HP-SEC, SEM, AFM, TGA-DSC, FTIR, NMR, and PMP-HPLC analyses. The putative structure of the extracted citrus pectin (CP) was analysed and elucidated through enzyme-assisted hydrolysis in correlation with ESI-MS and monosaccharide composition. The developed extraction methods are expected to influence the industrial process for the valorisation of CWs and implement the circular bio-economy.

Evaluation of the Potentials of Tobacco Waste Extract as Wood Preservatives against Wood Decay Fungi

Utilizing conventional wood preservatives poses potential risks to ecosystems and human health. Therefore, the wood protection industry must develop alternatives that are both efficient and environmentally friendly. In this paper, industrial tobacco waste extracts were used as eco-friendly wood preservatives against wood decay fungi. Three major constituents in the extracts were identified via gas chromatography-mass spectrometry (GC-MS) and included nicotine, neophytadiene, and 2,7,11-cembratriene-4,6-diol. The antifungal activities of waste tobacco extracts and these three major constituents against wood decay fungi were tested. At a concentration of 40 mg/mL, the tobacco waste extract treated with 50% ethanol significantly inhibited the activity of wood decay fungi. This was because the extract contained nicotine as the primary active component and neophytadiene as a synergistic active component. Wood decay resistance tests were conducted on Pinus yunnanensis and Hevea brasiliensis treated with a 50% ethanol extract of tobacco waste at a concentration of 40 mg/mL. The mass losses of Pinus yunnanensis exposed to G. trabeum and T. versicolor were 4.11% and 5.03%, respectively, while the mass losses in Hevea brasiliensis exposed to G. trabeum and T. versicolor were 7.85% and 9.85%, respectively, which were classified as highly resistant. The acute ecotoxicity of the tobacco waste extract was assessed using a kinetic luminescent bacteria test with Aliivibrio fischeri, which revealed significantly lower acute toxicity than a commercial copper-based wood preservative. This study offers insights into high-value utilization of tobacco waste and advancement of natural wood preservatives.

Critical Raw Materials Supply: Challenges and Potentialities to Exploit Rare Earth Elements from Siliceous Stones and Extractive Waste

Critical raw materials (CRMs) supply is a challenge that EU countries have to face, with many thinking about domestic procurement from natural ore deposits and anthropogenic deposits (landfills and extractive waste facilities). The present research focuses on the possibilities linked to the supply of CRMs and the potential for exploiting rare earth elements (REEs), investigating a large variety of extractive waste and siliceous rocks in the Piedmont region (Northern Italy). Indeed, the recovery of REEs from the extractive waste (EW) of siliceous quarries and other siliceous ore deposits can be a valuable way to reduce supply chain risks. Starting with a review of the literature on mining activities in Piedmont and continuing with the sampling and geochemical, mineralogical, petrographic, and environmental characterization of EW facilities connected to siliceous dimension stones, of kaolinitic gneiss ore deposits, and of soils present near the investigated areas, this study shows that the degree of REEs enrichment differs depending on the sampling area (soil or EW) and lithology. The concentration of REEs in the EW at some sampling sites fulfils the indicators of industrial-grade and industrial recovery; the high cumulative production and potential market values of EW and the positive recovery effects through proven methodologies indicate a viable prospect of REE recovery from EW. However, REE recovery industrialization faces challenges such as the difficulty in achieving efficient large-scale recovery due to large regional differences in REE abundance, the mismatch between potential market value and waste annual production, etc. Nonetheless, in the future, EW from dimension stone quarries could be differentially studied and reused based on the enrichment and distribution characteristics of trace elements. The present paper shows investigation procedures undertaken to determine both CRMs potentialities and environmental issues (on the basis of literature data employed to select the more-promising areas and on sampling and characterization activities in the selected areas), together with procedures to determine the waste quantities and tentative economic values of REEs present in the investigated areas. This approach, tested on a large area (Piedmont region), is replicable and applicable to other similar case studies (at EU and non-EU levels) and offers decision makers the possibility to acquire a general overview of the potential available resources in order to decide whether and where to concentrate efforts (including economic ones) in a more detailed study to evaluate the exploitable anthropogenic deposits.

Selective Extraction and Determination of Scandium in Industrial Waste (Matte) by the Complexometric Method

In this article, selective extraction and complexometric titration of scandium waste (waste matte) are investigated. Waste matte contains various ions of elements As, Pb, Sb, K, Hg, Fe, Ca, Au, Cd, Na, Si that interfere with the determination of scandium. In a moderately acidic medium, scandium ions form a mixed complex with diantipyrylmethane in the presence of iodide ions, which is well soluble in chloroform. Under these conditions, lanthanides as well as As, Pb, Sb, K, Hg, Fe, Ca, Au, Cd, Na do not form compounds soluble in chloroform and do not interfere with the determination of scandium. Scandium is reextracted with an ammonia solution of EDTA and the determination is completed complexometrically.

Analytically monitored cultivation of Arthrospira platensis on food waste extracts to compose a sustainable, low-prized, Zarrouk-based medium

ABSTRACT A sustainable, low-cost medium based on food waste for cultivating the cyanobacterium Arthrospira platensis (A. platensis) was investigated. Zarrouk medium components, especially phosphate, were substituted with extracts from beetroot peel, brewer’s grains, and walnut press cake. Ion concentrations of magnesium, calcium, iron, potassium, sodium, phos-phate, nitrate, sulfate, and chloride were analyzed to determine the optimal medium composition. Walnut press cake and brewer’s grains extracts showed high potential due to their magnesium, calcium, and phosphate content. Brewer’s grains extracts also provided glucose as an additional carbon source. Cultivations in shaking flasks and a photobioreactor (PBR) monitored cell growth through optical density and biomass concentration. The excess of magnesium and reduced phos-phate concentrations positively affected biomass production. A. platensis’s ability to metabolize glucose resulted in 68% higher biomass production. Growth in brewer’s grains extract required no additional phosphate. PBR cultivation showed A. platensis consumed significant magnesium and nitrate, achieving higher biomass concentrations with optimized gas exchange and light reflection systems.

Utilization of Organic Waste as A Natural Detector of Formaldehyde on-Campus Snacks

The aim of this research is to reduce household organic waste through the use of organic waste as a natural detector of formaldehyde content in food snacks. The organic waste used in this study was red garlic skins, dragon fruit skins and purple sweet potato skins. This research is an experimental research. The stages of the research started with the extraction of anthocyanins from the three organic wastes, direct detection of formalin and detection of food ingredients. The formalin concentrations tested were 0.5%, 1%, 2%, 5% and 25%. Detection ability can be seen from the color change between control and formalin treatment. Garlic skin produces a red extract, dragon fruit skin produces an orange extract, and purple sweet potato skin produces a deep red extract. Test results on 20 samples of food snacks around the campus using the three organic waste extracts proved that all samples contained formaldehyde in varying concentrations. The highest 50% formalin content was found in yellow noodles and meatballs. The conclusion is that purple beetle skin, dragonfruit skin, and red garlic skin can be used as natural detectors for formalin in campus snacks.

PH-switchable hydrophobic deep eutectic solvents for sustainable recycling extraction of high oily waste

The accumulation of oily waste increases annually with the growth in crude oil demand. Its toxicity and high heating value present both opportunities and challenges for treatment technologies. In recent years, the emergence of hydrophobic deep eutectic solvents (HDES) has promoted advancements in low-toxicity extraction processes. Leveraging the advantages of HDES and addressing the challenges posed by real oily sawdust (with a 67.9 % oil content), this study presents a novel green HDES solvent composed of ethyl maltol and fatty acids, accompanied by a corresponding extraction process. At a low temperature of 60 °C, the process achieved impressive results: an oil extraction efficiency close to 86.3 %, a dehydration rate exceeding 92.2 %, and a heavy metal removal rate ranging from 15 % to 75 %. In the exploration of solvents recycling, pH-switching facilitated the deprotonation and protonation of phenol-fatty acid HDES, promoting effective recovery of the oil phase. Even after 5 cycles, the oil extraction rate could still be maintained above 75 %. It is worth noting that the regenerated HDES exhibited greater selectivity for extracting light oil after multiple uses. The total ratio of saturated and aromatic hydrocarbons reached approximately 81.7 %, significantly enhancing the value of the recovered oil. Integrating systematic characterization with the extraction performance, as well as the variation in recovered oil phase components, highlighted the multifaceted effects of introducing ethyl maltol. Specifically, this effect is demonstrated in its ability to enhance the oil phase’s solubility by regulating the intermolecular spacing of HDES, and to impede the dissolution of heavy oil into its gaps by optimizing the local zone through the formation of complexes with HDES and heavy metals.

Eco-conscious corrosion inhibitor synthesis via Soxhlet extraction: experimental study in HCl 1M and theoretical analysis using DFT and MC simulations

ABSTRACT This study investigates the inhibitory potential of a hydroalcoholic extract from tea waste, using the Soxhlet method, against C38 corrosion in hydrochloric acid. Electrochemical tests, including EIS and PDP, evaluated the impact of extract concentration and immersion time on corrosion inhibition. SEM/EDS analysis was performed to examine the adsorption process. The results show that inhibitor concentration significantly affects corrosion inhibition, with inhibitory efficiency (IE) values up to 97.98% according to IE and Tafel curves. Increasing extract concentration enhances corrosion inhibition via surface adsorption, following the Langmuir model, resulting in a gradual increase in charge transfer resistance over time. Maximum inhibitory efficiency is reached after 6 hours, demonstrating time-dependent corrosion inhibition. SEM analysis confirms the adsorption mechanism. In summary, this study highlights the inhibitory potential of green tea waste extracts against C38 steel corrosion in hydrochloric acid, suggesting sustainable corrosion protection methods. Theoretical methods, including DFT and MC approaches, were used to analyse the interactions between hydrochloric acid, water, and the iron surface, as well as the adsorption of catechin on Fe (110) and Fe2O3 (110) surfaces. DFT results align well with MC simulations and experimental measurements, revealing a significant correlation between molecular structure and inhibitory efficacy.

Antibacterial Activity Potential of Industrial Food Production Waste Extracts against Pathogenic Bacteria: Comparative Analysis and Characterization.

The Food and Agricultural Organization estimates a 17% loss in the food production chain, making it imperative to adopt scientific and technological approaches to address this issue for sustainability. Industrial food production waste and its value-added applications, particularly in relation to a wide variety of pathogenic microorganisms and the health-related effects have not been thoroughly investigated. This study explores the potential of food production waste extracts-lemon peel (LP), hot trub (HT), and coffee silverskin (CSS) as sources of bioactive compounds. Extraction was conducted using hydro-methanolic extraction with yields in LP (482 mg/1 g) > HT (332 mg/1 g) > CSS (20 mg/1 g). The agar diffusion assay revealed the substantial antibacterial activity of all three extracts against Erwinia Amylovora, Escherichia coli, Bacillus subtilis, and Bacillus aquimaris. All extracts demonstrated activity against Gram-positive and Gram-negative bacteria, displaying minimum inhibitory concentrations effective against pathogenic bacteria like Listeria monocytogenes, Staphylococcus aureus, Vibrio parahaemolyticus, and Salmonella enterica. Total phenolic content (TPC in mg GAE/1g) was 100, 20, and 100 for CSS, HT, and LP, respectively. Antioxidant activity by ABTS indicated IC50 of 3.09, 13.09, and 2.61 for LP, HT, and CSS, respectively. Also, the antioxidant activity of the extracts was further confirmed by DPPH assay with the best activity in CSS (9.84 GAEg-1) and LP (9.77 mg of GAEg-1) rather than in HT (1.45 GAEg-1). No adverse cytotoxic effects on HaCaT cells were observed. Pancreatic amylase inhibition demonstrated antidiabetic potential, with LP showing the highest levels (92%). LC-MS characterization identified polyphenols as the main compounds in CSS, prenylated compounds in HT, and flavanols in LP. The findings imply the potential sustainable use of food production waste in industry.

Eco-friendly corrosion inhibition of steel in acid pickling using Prunus domestica Seeds and Okra stems extracts

The corrosion inhibition process during acid pickling in petroleum industries often employs toxic chemicals, facing stringent environmental regulations. This study explores a sustainable alternative by investigating the inhibitory effects of eco-friendly food waste extracts, namely Prunus domestica seeds (P.S) and Okra stems (O.St), on B7 grade steel corrosion in 1.0 M HCl aqueous solution, simulating an acid pickling environment. The corrosion inhibition efficiency was estimated via both electrochemical methods, including electrochemical impedance spectroscopy and potentiodynamic polarization techniques, and chemical methods, such as weight loss measurements. Fourier transform infrared spectroscopy (FTIR) and Gas chromatography-mass spectrometry (GC-MS) elucidated the extracts' main functional groups and potential chemical constituents. Remarkably, both extracts exhibited a maximum inhibitory efficiency of up to 80 %. Adsorption isotherms were employed to analyze the inhibition mechanisms, including Langmuir and Flory–Huggins models, alongside the Kinetic-thermodynamic model. Activation parameters have been obtained using Arrhenius and transition state equations. The synthesis of the activated complex is characterized as an endothermic process, as evidenced by the positive values of enthalpy of activation (ΔH*). Conversely, negative entropy of activation (ΔS*) values indicate that the activated complex signifies a process of association rather than separation. Quantum chemical calculations identified potential active inhibitor compounds within the extracts. The quantum parameters, including ionization potential, electronegativity, softness, and hardness of the chemical constituents of the extracts, were calculated using DFT with the B3LYP/6–31 G(+) method. This study underscores the innovative approach of utilizing waste food extracts as corrosion inhibitors, addressing environmental concerns while offering practical implications for industrial applications.