Almond Skin Research Articles

Almond skin derived porous biocarbon nanoarchitectonics with tunable micro and mesoporosity for CO2 adsorption and supercapacitors

The careful selection of carbon precursors for chemical activation is critical in obtaining cost-effective and efficient porous activated biocarbons with multifunctional properties. Herein, we report on utilising almond skin to synthesize porous activated biocarbons via solid-state KOH activation. Through precise manipulation of the impregnation ratio of KOH to the non-porous carbon, a range of materials with intriguing properties including high surface area, large pore volume, tunable micro and mesopores, and surface functionalization with oxygen were synthesized. The optimized material ASPC5-4 displayed an extremely high surface area (3535 m2 g−1), a large pore volume (1.9 cm3 g−1), a high proportion of mesopores (96.5 %) and a notable surface oxygen content (6.93 wt %). These excellent features allowed ASPC5-4 to adsorb a record amount of CO2 at 0 °C/30 bar (39.81 mmol g−1). Another material ASPC5-2 exhibited a high content of micropores and adsorbed 5.92 mmol g−1 of CO2 at 0 °C/1 bar. ASPC5-4 also exhibited great potential as a supercapacitor electrode, displaying a high specific capacitance in both a three-electrode (354 F g−1/0.5 A g−1) and two-electrode (203 F g−1/0.5 A g−1) systems. It also demonstrated high power and energy densities of 638 W kg−1 and 47 W h kg−1, respectively.

Reuse of almond by-products: Scale-up production of functional almond skin added semolina sourdough breads

The present work reports the application of powdered almond skin (PAS) for industrial bread production. Three trials were conducted involving seven bread shapes, including control production (CTR), and two experimental productions with PAS addition [5–10 % (w/w), 5-PAS and 10-PAS, respectively]. Sourdough inoculum determined the acidification of all doughs and the levels of lactic acid bacteria increased. Spore-forming aerobic bacteria, members of the Enterobacteriaceae family, and total coliforms were not detected until the end of the fermentation process. PAS addition determined a lower weight loss, an increase of firmness, a diminution of specific volume, and a different sensory profile of the breads. Mafalda was the most appreciated bread shape and was subjected to photothermal aging. 10-PAS sample, after nine-day stress, still showed a significant total phenolic compound TPC content (111.0 mg GAE/g extract). The radical scavenging potential increased with PAS with a final IC50 of 103.3 μg/mL in 10-PAS breads. Experimental breads exhibited a notable enhancement in protection against lipid peroxidation. Mold-free shelf life assessment showed a 10-day shelf life for CTR breads, while a 12-day shelf life in presence of PAS. Collectively, the data suggest that PAS holds significant promise as a functional additive for industrial production of bread.

Industrial upcycling of almond skin through production of novel brioches

The global sustainability policy emphasizes reusing of agri-food waste and by-products to enhance food bioactive properties. Thus, brioches were processed incorporating almond skin powder (ASP): control (CTR), without ASP addition; 5-ASP, with 5% (w/w) ASP; and 10-ASP, with 10% (w/w) ASP. Seven different brioches shapes were obtained for each recipe. Flavonoids were mainly detected in Tuono almond skin by Ultra-High Performance Liquid Chromatography coupled to High-Resolution Mass Spectrometry (UHPLC-HRMSMS), in particular, flavan-3-ol monomers. The ethanolic extract of Tuono almond skins contained polar lipids (oxylipins and phospholipids). Gas Chromatography–Mass Spectrometry (GC-MS) identified six major fatty acids, mainly oleic acid (48.01%). Photothermal degradation impact on bioactive compounds was evaluated using a first-order kinetic model. Antioxidant activity was studied using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl and β-carotene bleaching test. α-amylase, α-glucosidase, and lipase inhibitory effect were also tested. The acidification of the doughs was consistent across all trials. Lactic acid bacteria and yeast levels increased. Importantly, the final products were free from undesirable microorganisms. The addition of ASP led to reduced weight loss and specific volume for all seven brioche types. Furthermore, the firmness, crumb structure, and sensory profile of the final products were noticeably influenced. Tasters clearly favoured the Treccina brioches. The production of sweet leavened baked goods was carried out in triplicate in two independent experiments. The statistical model applied to the data considered the effects of brioche shape and the addition of ASP. Kinetic data revealed that the half-life extension for both total phenol and flavonoid content was observed in the 10-ASP sample (18.00382). 10-ASP sample exhibited promising ABTS radical scavenging activity, with inhibitory concentration 50% (IC50) values of 18.64 mg/mL after 9 days of photothermal degradation. Moreover, when testing 10-ASP Treccina against α-amylase and α-glucosidase, the IC50 values were 198.16 and 190.23 μg/mL, respectively, even after 9 days.

The Potential of Almond Skin as a Sustainable Biomaterial for Eliminating Azo Dye in Aqueous Media

The Potential of Almond Skin as a Sustainable Biomaterial for Eliminating Azo Dye in Aqueous Media

Recent Innovations on the Reuse of Almond and Hazelnut By-Products: A Review

Nuts consumption has increased significantly in the last 10 years, especially driven by the stimulated awareness of their possible beneficial health effects. Increased nuts consumption is linked to an obvious accumulation of by-products and waste. With the view of the circular economy, the aim of this review is to analyse the recent and innovative approaches able to valorise the by-products derived from almonds and hazelnuts, two important nut products of the Italian scene, with historical and traditional importance. The most important solutions are concerned with reuse of almond hull, shell, skin, oil cake, and hazelnut shell; skin and oil cake are often considered waste or by-products. Many interesting implications in the feed and food sectors have been detected in the last ten years, aimed at designing innovative materials developed from by-products and extraction of bioactive molecules for different purposes. The perspective chosen to discuss the topic is related to the sustainability of these processes, in terms of both the environment and economy. The circular economy supports a zero-waste approach, which should not also be meant as a zero-cost process in terms of the level of technology that has been partially developed.

1-D Carbon Nano-Coils Derived from Almond Skin: Exhibiting Density of State, Diffusivity, Electron Transfer Rate, and Dopamine Redox Modulation Properties Akin to Graphene Oxide.

The quest to develop graphene-like biomass-carbon for advanced biomolecule redox modulation and sensing remains a challenge. The primary obstacle is the limited ability of biomass to undergo extensive graphitization during pyrolysis resulting in the formation of amorphous carbon materials with a small carbon-double-bond-carbon domain size (Lsp2), density of state (LDOS), ion diffusivity (D), and electron transfer rate constant (Ks). Herein, using almond skin (AS) the morphology of biomass is demonstrated as the key to overcoming these limitations. AS consists of 1D syringyl/guaiacyl lignin nano-coils which under H2/H2 annealing transform into pyrolytic 1D carbon nano-coils (r-gC). Spectroscopy and microscopy analyses reveal that the sheet layering structure, crystallinity, LDOS, and Lsp2 of r-gC mimic those of graphene oxide (GO). Moreover, its unique 1D morphology and profound microstructure facilitate faster charge transfer and ion diffusion than GO's planar structure, leading to better redox modulation and sensing of the neurotransmitter dopamine (DA) in physiological fluids. r-gC's DA detection limit of 3.62nM is below the lower threshold found in humans and on par with the state-of-the-art. r-gC is also DA-selective over 14 biochemicals. This study reveals that biomasses with well-defined and compact lignin structures are best suited for developing highly electroactive graphene-like biomass carbon.

Selection of lactic acid bacteria from home-made sourdoughs for resistance to the main almond skin polyphenols

The aim of this research was to identify lactic acid bacteria (LAB) that could be used as starter strains in sourdough made with almond peel powder to create novel fermented functional bakery products. Physicochemical characteristics and LAB were analyzed from ten home-made sourdoughs used at the family level in western Sicily (Italy). The pH (3.57–4.80) and TTA (8.20–14.20 mL 0.1 N NaOH/10 g) were inversely correlated. LAB dominated all sourdoughs, and the highest cell densities (6.74–9.28 log cfu/g) were detected on the medium Sour Dough Bacteria, except for one sample. Among LAB groups, the lowest counts (4.92–6.19 log cfu/g) were obtained on M17 used for LAB cocci. Yeasts were lower than LAB from two to four orders of magnitude with values between 3.93 and 6.11 log cfu/g. Twenty strains belonging to the species Enterococcus gilvus, Fructilactobacillus sanfranciscensis, Lacticaseibacillus paracasei, Lactiplantibacillus pentosus, Lactiplantibacillus plantarum, Lactococcus lactis, Lentilactobacillus buchneri, Lentilactobacillus diolivorans, Leuconostoc citreum, Leuconostoc holzapfelii, Levilactobacillus brevis, Pediococcus pentosaceus, and Weissella cibaria were identified. Eleven out of the 20 strains identified showed the ability to grow in presence of 16 polyphenols characterizing the peel of almonds. Eight of these LAB strains dropped pH below 4.5 after 6–8 h of fermentation, and two strains showed a strong inhibitory effect against Listeria monocytogenes ATCC19114 with inhibition diameters around the wells >19 mm. Thus, all acidifying strains were selected to produce sourdough bakery goods enriched with almond skin powder.

A simple and coast effective quinoline based Schiff’s base SS-2 as a colorimetric chemosensor for highly selective detection of cyanide ion in food samples

A simple, cost-effective, and highly selective colorimetric chemosensor was designed and synthesized (E)-2-(4-chlorophenoxy)-3-((2-(4-nitrophenyl) hydrazono) methyl) quinoline SS-2 from 2-(4-Chlorophenoxy) quinolin-3-carbaldehyde and 4-Nitrophenylhydrazine and confirmed by spectral techniques. The receptor SS-2 was found to exhibit a colorimetric response of the colour change from yellow to blue towards CN− ion, due to de-protonation and intra-ligand charge transfer. The receptor SS-2 interacts with cyanide in a 1:1 stoichiometric manner with a detection limit of 5.39 × 10−7 M. Receptor SS-2 could be recyclable by treatment of Tri fluoro acetic acid. The sensing behaviour of the receptor was further enunciated by computational studies and found to efficiently detect even the trace amounts of cyanide present in food samples such as flax seeds, apple seeds, kidney beans, sprout potatoes, and almond skin. In further SS-2 can be used for practical applications like visible colorimetric test kits such as dipsticks.

A Green Bioactive By-Product Almond Skin Functional Extract for Developing Nutraceutical Formulations with Potential Antimetabolic Activity

(1) Background: almond peels are rich in polyphenols such as catechin and epicatechin, which are important anti-free-radical agents, anti-inflammatory compounds, and capable of breaking down cholesterol plaques. This work aims to evaluate the biological and technological activity of a “green” dry aqueous extract from Sicilian almond peels, a waste product of the food industry, and to develop healthy nutraceuticals with natural ingredients. Eudraguard® Natural is a natural coating polymer chosen to develop atomized formulations that improve the technological properties of the extract. (2) Methods: the antioxidant and free radical scavenger activity of the extract was rated using different methods (DPPH assay, ABTS, ORAC, NO). The metalloproteinases of the extracts (MMP-2 and MMP-9), the enhanced inhibition of the final glycation products, and the effects of the compounds on cell viability were also tested. All pure materials and formulations were characterized using UV, HPLC, FTIR, DSC, and SEM methods. (3) Results: almond peel extract showed appreciable antioxidant and free radical activity with a stronger NO inhibition effect, strong activity on MMP-2, and good antiglycative effects. In light of this, a food supplement with added health value was formulated. Eudraguard® Natural acted as a swelling substrate by improving extract solubility and dissolution/release (4) Conclusions: almond peel extract has significant antioxidant activity and MMP/AGE inhibition effects, resulting in an optimal candidate to formulate safe microsystems with potential antimetabolic activity. Eudraguard® Natural is capable of obtaining spray-dried microsystems with an improvement in the extract‘s biological and technological characteristics. It also protects the dry extract from degradation and oxidation, prolonging the shelf life of the final product.

Subcritical Water Extraction for Valorisation of Almond Skin from Almond Industrial Processing.

Almond skin (AS) is an agro-industrial residue from almond processing that has a high potential for valorisation. In this study, subcritical water extraction (SWE) was applied at two temperatures (160 and 180 °C) to obtain phenolic-rich extracts (water-soluble fraction) and cellulose fibres (insoluble fraction) from AS. The extraction conditions affected the composition and properties of both valorised fractions. The dry extracts obtained at 180 °C were richer in phenolics (161 vs. 101 mg GAE. g-1 defatted almond skin (DAS)), with greater antioxidant potential (1.063 vs. 1.490 mg DAS.mg-1 DPPH) and showed greater antibacterial effect (lower MIC values) against L. innocua (34 vs. 90 mg·mL-1) and E. coli (48 vs. 90 mg·mL-1) than those obtained at 160 °C, despite the lower total solid yield (21 vs. 29%) obtained in the SWE process. The purification of cellulose from the SWE residues, using hydrogen peroxide (H2O2), revealed that AS is not a good source of cellulose material since the bleached fractions showed low yields (20-21%) and low cellulose purity (40-50%), even after four bleaching cycles (1 h) at pH 12 and 8% H2O2. Nevertheless, the application of a green, scalable, and toxic solvent-free SWE process was highly useful for obtaining AS bioactive extracts for different food, cosmetic, or pharmaceutical applications.

The possibility of spreading herpes simplex virus type 1 via food handling and sharing.

Herpes simplex virus type 1 (HSV-1) is an enveloped virus that causes recurrent and incurable diseases in 67% of the world population. Although it is not listed as a foodborne virus, some studies have shown that it can be recovered from surfaces as well as food. We investigated its persistence at -20°C, 4°C, 20°C or 37°C for up to 7 days on stainless steel, aluminum, glass, polypropylene, cheddar cheese, sliced almond, and apple skin and in cola soft drink, orange juice, coffee, and milk as well as its transferability from stainless steel to dry or moistened nitrile or latex gloves over time at typical ambient temperatures. Based on plaque assay on Vero cells, HSV-1 persisted at least 24h on all surfaces and at least 1h on food matrices but was inactivated quickly in cola soft drink. Temperature and pH affected HSV-1 infectivity. Transfer of HSV-1 at a contact pressure of 1kg cm2-1 for 10s occurred only on latex, especially moistened. Our data on the persistence of HSV-1 on food-related surfaces suggest that some risk may be associated with sharing foods with infected carriers.

Antioxidant Activity of a Sicilian Almond Skin Extract Using In Vitro and In Vivo Models.

Almond skins are known for their antioxidative and anti-inflammatory properties, which are mainly due to the presence of polyphenols. The aim of the present study was to evaluate the antioxidant and anti-inflammatory effects of almond skin extract (ASE) obtained from the Sicilian cultivar "Fascionello" and to evaluate the possible mechanisms of action using an in vitro model of human monocytic U937 cells as well as an in vivo model of carrageenan (CAR)-induced paw edema. The in vitro studies demonstrated that pretreatment with ASE inhibited the formation of ROS and apoptosis. The in vivo studies showed that ASE restored the CAR-induced tissue changes; restored the activity of endogenous antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione; and decreased neutrophil infiltration, lipid peroxidation, and the release of proinflammatory mediators. The anti-inflammatory and antioxidant effects of ASE could be associated with the inhibition of the pro-inflammatory nuclear NF-κB and the activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2) antioxidant pathways. In conclusion, almond skin could reduce the levels of inflammation and oxidative stress and could be beneficial in the treatment of several disorders.

Chemical and Sensory Properties of Waffles Supplemented with Almond Skins.

Almonds are one of the most produced nuts worldwide and numerous studies have shown that they have nutritional and medicinal characteristics, which gives them the possibility of being applied in various products. However, several by-products are generated during their production, which have characteristics of interest but remain underutilised, namely, the almond skins. This work aimed to study samples of waffles supplemented with almond skins. The waffles were evaluated for their total polyphenol content, antioxidant capacity, total flavonoids, ortho-diphenols, soluble sugars, starch, texture, and colour. They were also sensorially evaluated using a panel of tasters specialised in this type of evaluation and a quantitative descriptive analysis test (QDA) sensory test. The results showed that the waffles with the highest levels of phenolic compounds as well as the highest antioxidant activity (by the ABTS, DPPH, and FRAP methods) were the waffles supplemented with 10% almond skin. The total phenol contents obtained for the prepared extracts varied between 0.127 mg GAE/g and 0.415 mg GAE/g, the flavonoid contents ranged from 0.067 mg CAE/g to 0.339 mg CAE/g and the ortho-diphenol contents varied between 0.163 mg ACE /g and 0.303 mg ACE/g. Regarding the quantification of soluble sugars, the values were presented in percentage of fresh weight, and ranged from 30.148 to 38.054%; regarding the quantification of starch, the percentages varied from 14.488 to 21.982%. Sensorially, we verified that the samples were statistically different in terms of the descriptors "colour", "roasted aroma", and "dissolubility", with a higher score in these descriptors for the waffles with 10% of almond skin. This process of obtaining waffles, which can be industrialised, is interesting from both a nutritional point of view and for the possibility of creating new, differentiated, and innovative products.

Carbonyl-interfaced-biochar derived from unique capillary structures via one-step carbonization with selective methyl blue adsorption capability

Biochar dye adsorbents are touted as “green” and low-cost compared to metals/oxides and polymers. However, the most active of them require some form of multi-step chemical activation with toxic chemicals which tarnish their credentials. Going forward, there is a need to develop low-toxic chemical activators or discover new biomass sources that can generate high-value biochar adsorbents via physical activation. Herein, we demonstrate that unlike other biomass waste almond skin (WA-s) contains a unique network of lignocellulosic capillary-like structures (CN) buried inside a dense lignocellulosic shell. Via one-step carbonization at 900 °C under N2, the shell is removed exposing CN which transforms into defect-rich carbon macrostructures (AS-C-T). Data from spectroscopy analysis indicate that AS-C-T has the special ability to undergo carbonylation, at high temperatures, creating moderate acidic carbonyl (CO) interfaces that form selective hydrogen bonds with the acidic hydrogen of zwitterion methyl blue (MB), at pH 6.2 to 7.2. Such interactions induce high MB adsorption capacity (>3000 mgg−1) and selectivity comparable to the state-of-the-art. The hydrogen bonding is strong and irreversible; however, it creates secondary interfaces which ensure high recyclability. The adsorption reaction is endothermic and modeled by the pseudo-second-order kinetic, Langmuir, and Intra-particle diffusion. Practically, AS-C-T can be retrofitted to commercial filters to produce pathogen- and dye-free water. These properties make AS-C-T a potential “green” and low-cost adsorbent for dye effluents. Our results hint at the fact that biomass sources with intricate capillary structures might have unique interfacial properties which are useful for preparing high-value biochar adsorbents without chemical activation.

Reuse of almond by-products: Functionalization of traditional semolina sourdough bread with almond skin

Almond production generates large amounts of by-products rich in polyphenols. In this study, almond skin was explored as a valuable food ingredient in bread making. To this purpose, almond skin was used to produce functional products modifying a traditional sourdough bread recipe. The doughs were prepared replacing semolina with powdered almond skin (PAS) at 5 and 10 % (w/w). Sourdough inoculum was started with a mix of lactic acid bacteria (LAB) and propagated in semolina until reaching pH 3.7. The pH of PAS added breads was higher than that of control (CTR) breads before and after fermentation. Plate counts showed a similar evolution of LAB and total mesophilic microorganisms, but members of Enterobacteriaceae and coliform were detectable in PAS doughs. Illumina data clearly showed a dominance of lactobacilli in all trials, but PAS doughs displayed the presence of Bacillus. The final bread characteristics were influenced by PAS and its addition percentage; in particular, crust and crumb colour resulted darker, the alveolation decreased and, regarding sensory attributes, odour intensity increased, while bread odour diminished. In presence of PAS, bread emissions were characterized by lower percentages of alcohols and aromatic hydrocarbons and higher percentages of the other volatile compound classes, especially terpenoids like β-pinene, β-myrcene and limonene than CTR trial. After in vitro simulated digestion, the final release of phytochemicals from 10 % PAS bread was almost 100 %. Thus, PAS determined an increase of the antioxidant capacity of the breads. Phytochemicals released from digested PAS-fortified bread can provide antioxidant protection in a complex biological environment such as human intestinal-like cells. Besides the positive functional properties of PAS, this work also evidenced the hygienic issues of almond skin and, in order to avoid potential risks for the human health, highlighted the need to preserve its microbiological characteristics during storage for their reuse in bread production.

A Systematic Review of Second-Line Treatments in Antiviral Resistant Strains of HSV-1, HSV-2, and VZV.

Drug-resistant variants of herpes simplex viruses (HSV) have been reported that are not effectively treated with first-line antiviral agents. The objective of this study was to evaluate available literature on the possible efficacy of second-line treatments in HSV and the use of second-line treatments in HSV strains that are resistant to first-line treatments. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a final search was conducted in six databases on November 5, 2021 for all relevant literature using terms related to antiviral resistance, herpes, and HSV. Eligible manuscripts were required to report the presence of an existing or proposed second-line treatment for HSV-1, HSV-2, or varicella zoster virus (VZV); have full-text English-language access; and potentially reduce the rate of antiviral resistance. Following screening, 137 articles were included in qualitative synthesis. Of the included studies, articles that examined the relationship between viral resistance to first-line treatments and potential second-line treatments in HSV were included. The Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. Due to the heterogeneity of study designs, a meta-analysis of the studies was not performed. The dates in which accepted studies were published spanned from 2015-2021. In terms of sample characteristics, the majority (72.26%) of studies used Vero cells. When looking at the viruses on which the interventions were tested, the majority (84.67%) used HSV-1, with (34.31%) of these studies reporting testing on resistant HSV strains. Regarding the effectiveness of the proposed interventions, 91.97%were effective as potential managements for resistant strains of HSV. Of the papers reviewed, nectin in 2.19% of the reviews had efficacy as a second-line treatments in HSV, amenamevir in 2.19%, methanol extract in 2.19%, monoclonal antibodies in 1.46%, arbidol in 1.46%, siRNA swarms in 1.46%, Cucumis melo sulfated pectin in 1.46%, and components from Oleaeuropeae in 1.46%. In addition to this griffithsin in 1.46% was effective, Morus alba L. in 1.46%, using nucleosides in 1.46%, botryosphaeran in 1.46%, monoterpenes in 1.46%, almond skin extracts in 1.46%, bortezomib in 1.46%, flavonoid compounds in 1.46%, andessential oils were effective in 1.46%, but not effective in 0.73%. The available literature reviewed consistently supports the existence and potentiality of second-line treatments for HSV strains that are resistant to first-line treatments. Immunocompromised patients have been noted to be the population most often affected by drug-resistant variants of HSV. Subsequently, we found that HSV infections in this patient population are challenging to manage clinically effectively. The goal of this systematic review is to provide additional information to patients on the potentiality of second-line treatment in HSV strains resistant to first-line treatments, especially those who are immunocompromised. All patients, whether they are immunocompromised or not, deserve to have their infections clinically managed in a manner supported by comprehensive research. This review provides necessary information about treatment options for patients with resistant HSV infections and their providers.

Anaerobic co-digestion of agro-industrial cashew nut wastes with organic matters for biogas production: case of cashew nut hull and cashew almond skin

The cashew nut wastes (CNW), more released in the environment by cashew nut transforming units, are underused based on bioenergy. This study aimed at evaluating the biogas production by the anaerobic codigestion of CNW with various organic feedstocks. Physicochemical parameters and lower heating value (LHV) of cashew nut hull (CH) and cashew almond skin (CS) were determined. Batch cultures of each waste, supplemented to pig manure (PM), cow dung (CD), fermentation sludge (FS), activated sludge (AS) and Macrotermes bellicosus termite gut homogenate (TGH), were performed in anaerobic and mesophilic conditions. The biogas and methane (CH4) were measured. CNW were acid (pH 5.86-6.44), with 86.80-92.38% volatile solids (VS) and slightly high carbon/nitrogen ratio (31.94-37.79). The LHV was 23.094 MJ/Kg and 18.113 MJ/Kg for CH and CS, respectively. The highest yields were retrieved with the co-digestion PM-CH (189.16 L biogas.kg-1 VS, 130.89 L CH4.kg-1 VS, and 69.2% CH4) and CD-CS (159.85 L biogas.kg-1 VS, 99.58 L CH4.kg1 VS, and 62.3% CH4). Therefore, to boost biogas and biomethane yield, it is necessary to adjust the C/N ratios to the optimal values, and maintain the pH to the neutral, and combine PM and CD as inoculum during the digestion process of CNW.

Effect of Almond Skin Waste and Glycidyl Methacrylate on Mechanical and Color Properties of Poly(ε-caprolactone)/Poly(lactic acid) Blends.

Blending Poly(lactic acid) (PLA) and Poly(ε-caprolactone) (PCL) is a promising strategy to enhance the properties of biodegradable materials. However, these compounds are thermodynamically immiscible and, consequently, compatibilization is required during polymer blending. Reinforced biocomposites can be obtained by adding agricultural wastes generated by industries which are forced to consider waste treatment methods to prevent environmental concerns. Novel PCL/PLA blends were proposed based on the addition of 10 wt.% almond shell (AS) waste combined with 3 wt.% glycidyl methacrylate (GMA) as a compatibilizer. Different PCL-, PLA-, and PCL/PLA-based blends at different percentages (75:25, 50:50, 25:75, 15:85) added with GMA and AS were obtained. The color results highlighted the lower transparency and brownish tone of the studied formulations after the addition of AS. The addition of PCL provided a positive effect on PLA's ductility due to its intrinsically higher flexibility. The combination of GMA and AS improved the mechanical properties of PCL, PLA, and 50:50 controls by reducing yield strength, yield strength at break, and elongation at break values. The 75:25_GMA_AS formulation showed a homogeneous visual appearance, low transparency, and desirable mechanical properties for rigid food packaging applications, reducing the final material cost through the revalorization of AS.

Analysis of the Antioxidant Activity, Lipid Profile, and Minerals of the Skin and Seed of Hazelnuts (Corylus avellana L.), Pistachios (Pistacia vera) and Almonds (Prunus dulcis)—A Comparative Analysis

Nuts are dry, single-seeded fruits with a combination of beneficial compounds that aid in disease prevention and treatment. The aims of this research are to evaluate the total antioxidant activity (AI) by ferric reducing antioxidant power (FRAP) assay, fatty acids by acid-catalyzed esterification method, and minerals by inductively coupled plasma optical emission (ICP-OE) spectrometer in hazelnuts, pistachios, and almond seeds and skins. Considering total AI, the results demonstrated that the highest activity was found in hazelnut and pistachio skin. The results considering minerals demonstrated that manganese, zinc, and iron levels are high in almond and hazelnut skins, copper is dominant in pistachio skin and hazelnut seed, and selenium is high in pistachio and almond skins and seed. Finally, the results showed palmitic acid is present in almond skin and pistachio seed, palmitoleic acid is high in almond and pistachio skins, and stearic acid is present in almond and hazelnut skins. Oleic acid was found in hazelnut seeds and their skin, linoleic acid in almond skin and pistachio seeds, and α-linolenic acid in almond and pistachio skins. In conclusion, hazelnut, pistachio, and almond skins are a great source of antioxidants, minerals, and healthy fatty acids, making them useful for nutraceutical development.

Treatment of Winery Wastewater by Combined Almond Skin Coagulant and Sulfate Radicals: Assessment of HSO5- Activators.

The large production of wine and almonds leads to the generation of sub-products, such as winery wastewater (WW) and almond skin. WW is characterized by its high content of recalcitrant organic matter (biodegradability index < 0.30). Therefore, the aim of this work was to (1) apply the coagulation-flocculation-decantation (CFD) process with an organic coagulant based on almond skin extract (ASE), (2) treat the organic recalcitrant matter through sulfate radical advanced oxidation processes (SR-AOPs) and (3) evaluate the efficiency of combined CFD with UV-A, UV-C and ultrasound (US) reactors. The CFD process was applied with variation in the ASE concentration vs. pH, with results showing a chemical oxygen demand (COD) removal of 61.2% (0.5 g/L ASE, pH = 3.0). After CFD, the germination index (GI) of cucumber and corn seeds was ≥80%; thus, the sludge can be recycled as fertilizer. The SR-AOP initial conditions were achieved by the application of a Box-Behnken response surface methodology, which described the relationship between three independent variables (peroxymonosulfate (PMS) concentration, cobalt (Co2+) concentration and UV-A radiation intensity). Afterwards, the SR-AOPs were optimized by varying the pH, temperature, catalyst type and reagent addition manner. With the application of CFD as a pre-treatment followed by SR-AOP under optimal conditions (pH = 6.0, [PMS] = 5.88 mM, [Co2+] = 5 mM, T = 343 K, reaction time 240 min), the COD removal increased to 85.9, 82.6 and 80.2%, respectively, for UV-A, UV-C and US reactors. All treated wastewater met the Portuguese legislation for discharge in a municipal sewage network (COD ≤ 1000 mg O2/L). As a final remark, the combination of CFD with SR-AOPs is a sustainable, safe and clean strategy for WW treatment and subproduct valorization.