Skin Extracts Research Articles

Eco-Friendly Larvicidal Activity of Matoa (Pometia Pinnata) Skin Extract against Mosquitoes

Using natural plants to combat diseases offers an alternative strategy for managing disease vectors transmitted by mosquitoes. One such beneficial plant is Pometia pinnata. Although some research has been conducted on the biological activity of P. pinnata, its potential as a mosquito larvicide remains unexplored. This study investigates the larvicidal efficacy of hexane extract from the skin of P. pinnata fruit against mosquito larvae. The fruit skin of P. pinnata was extracted using n-hexane solvent, followed by phytochemical screening. The larvicidal effectiveness of the extract was tested at concentrations of 25 ppm, 50 ppm, 75 ppm, 100 ppm, 200 ppm, 500 ppm, and 1000 ppm. The LC50 value of the n-hexane extract demonstrated significant larvicidal activity. The results indicate that the n-hexane extract of P. pinnata fruit skin has the potential to serve as a natural larvicide, providing an eco-friendly solution for mosquito control

Comparative Analysis of a Secondary Metabolite Profile from Leaves, Peel and Bulbs of Allium sativum L. by GC-MS

Garlic is a herbal plant that is widely used as a medicinal ingredient, because it contains secondary metabolite compounds such as alkaloids, flavonoids, tannins, phenols, terpenoids and saponins. The secondary metabolite content of plants is influenced by genetic, ontogenic, morphogenetic and environmental factors that can influence the biosynthesis and accumulation of secondary metabolites. Garlic is generally only used for the bulbs, while other parts such as the leaves and skin are still not widely used. This study aims to identify the secondary metabolite profile of ethanol extract of garlic leaves, bulbs and peels using the gas chromatography mass spectrometry (GC-MS) method. Identification of secondary metabolite compounds contained in each 70% ethanol extract was analyzed using the tube test, thin layer chromatography (TLC) and GC-MS methods. The results of analysis of secondary metabolite content using the tube test and TLC method showed that the ethanol extract of garlic leaves, skin and bulbs positively contained flavonoids, tannins, phenols and saponins. The results of secondary metabolite profile analysis using the GC-MS method from the ethanol extract of garlic skin and bulbs showed that 5 compounds were obtained with the main compound being 3,4-Dihydroxyphenylacetic acid and 23 compounds with the main compound being 1,2-Benzenedicaboxylic acid and palmitic acid, while the leek extract white only detected 1 compound. The conclusion is that the ethanol extract of garlic leaves, skin and bulbs has secondary metabolites in the form of flavonoids, tannins, phenols and saponins. There are differences in the profile of secondary metabolite compounds in the ethanol extract of garlic leaves, skin and bulbs in terms of the results of GC-MS analysis.

Study of the Incorporation of Gel and Aloe vera Peel Extract in a Polymer Matrix Based on Polyvinylpyrrolidone.

The development of dressings based on electrospun membranes with polymers and plant extracts is an interesting approach to skin regeneration, providing elements to prevent contamination and a matrix that accelerates the healing process. We developed a membrane composed of polyvinylpyrrolidone (PVP), gel and Aloe vera peel extract via the electrospinning technique. Additionally, an optimal ratio of PVP/Av gel/Av skin extract was determined to facilitate membrane formation. Electrospun membranes were obtained with fiber diameters of 1403 ± 57.4 nm for the PVP and 189.2 ± 11.4 nm for PVP/Av gel/Av peel extract, confirming that the use of extracts generally reduced the fiber diameter. The incorporation of gel and peel extract of Aloe vera into the electrospun membrane was analyzed via FTIR and UV-Vis spectroscopies. FTIR revealed the presence of functional groups associated with phenolic compounds such as aloin, aloe-emodin, emodin and aloesin, which was confirmed by UV-Vis, revealing absorption bands corresponding to aloin, phenols and carbonyl groups. This finding provides evidence of the effective integration and prevalence of bioactive compounds of a phenolic and polysaccharide nature from the gel and the Av skin extract in the electrospun fibers, resulting in an advanced membrane that could improve and accelerate the healing process and protect the wound from bacterial infections.

Antimicrobial Polymer Films with Grape Seed and Skin Extracts for Food Packaging.

The development of antimicrobial food packaging is a very important and current goal, but it still difficult to implement in practice. Reducing microbial contamination and preserving food quality are very important tasks for food manufacturers as the use of antimicrobial packaging can preserve the health of consumers. On the other hand, the difficulty of degrading packaging materials, leading to environmental pollution, is also an important problem. These problems can be solved by using biodegradable biopolymers and antimicrobial agents in the production of food packaging. Very suitable antimicrobial agents are grape seed and skin extracts as they have high antioxidant and antimicrobial capacity and are obtained from grape pomace, a waste product of winemaking. The present review presents the valuable bioactive compounds contained in grape seeds and skins, the methods used to obtain the extracts, and their antimicrobial and antioxidant properties. Then, the application of grape seed and skin extracts for the production of antimicrobial packaging is reviewed. Emphasis is placed on antimicrobial packaging based on various biopolymers. Special attention is also paid to the application of the extract of grape skins to obtain intelligent indicator packages for the continuous monitoring of the freshness and quality of foods. The focus is mainly placed on the antimicrobial properties of the packaging against different types of microorganisms and their applications for food packaging. The presented data prove the good potential of grape seed and skin extracts to be used as active agents in the preparation of antimicrobial food packaging.

Aspects of quercetin stability and its liposomal enhancement in yellow onion skin extracts

Quercetin is a flavonoid that occurs in many types of fruit and vegetables and is stable for no longer than 4.5 h in the investigated pH range (6.0–8.0), even at 4 °C in the dark. At higher temperatures, the degradation/oxidation process is much faster. Simple but effective proliposomal encapsulation was used to protect the quercetin from environmental conditions such as pH. With this approach, 65 to 90% of pure quercetin and quercetin-rich onion extract was kept after >60 days under conditions that favoured its oxidation (pH 7.4). In addition, the encapsulated quercetin decreases the lipid peroxidation induced by pulsed UV light by >50%. At a mass ratio of 1:100 quercetin to lipids (w/w), the liposomes remained intact in solutions for six months. Quercetin in lipid bilayers simultaneously protects the unsaturated lipids from peroxidation.

Lingonberry (Vaccinium vitis-idaea L.) Skin Extract Prevents Weight Gain and Hyperglycemia in High-Fat Diet-Induced Model of Obesity in Mice.

The percentage of obese people is increasing worldwide, causing versatile health problems. Obesity is connected to diseases such as diabetes and cardiovascular diseases, which are preceded by a state called metabolic syndrome. Diets rich in fruits and vegetables have been reported to decrease the risk of metabolic syndrome and type 2 diabetes. Berries with a high polyphenol content, including lingonberry (Vaccinium vitis-idaea L.), have also been of interest to possibly prevent obesity-induced metabolic disturbances. In the present study, we prepared an extract from the by-product of a lingonberry juice production process (press cake/pomace) and investigated its metabolic effects in the high-fat diet-induced model of obesity in mice. The lingonberry skin extract partly prevented weight and epididymal fat gain as well as a rise in fasting glucose level in high-fat diet-fed mice. The extract also attenuated high-fat diet-induced glucose intolerance as measured by an intraperitoneal glucose tolerance test (IPGTT). The extract had no effect on the levels of cholesterol, triglyceride or the adipokines adiponectin, leptin, or resistin. The results extend previous data on the beneficial metabolic effects of lingonberry. Further research is needed to explore the mechanisms behind these effects and to develop further health-promoting lingonberry applications.

Comparison of Total Antioxidant Capacities and Phenolic Constituents of Grapes Cultivated in Turkey for Wine Production

Grapes are renowned for their health-promoting properties due to polyphenols, particularly anthocyanins in red grapes and flavonols in white grapes. This study evaluated the total antioxidant capacities (TAC) of specific grape varieties (Sultaniye, Chardonnay, Shiraz, Carignan, Alicante Bouschet, and Merlot) using the CUPRAC (CUPric Reducing Antioxidant Capacity) and ABTS/HRP (2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)/horseradish peroxidase) methods. Additionally, total phenolic, flavonoid, and anthocyanin contents were determined via Folin Ciocalteu, AlCl3/NaNO2, and pH differential methods. Primary phenolic compounds were identified with High-Performance Liquid Chromatography-Photodiode Array (HPLC-PDA). TAC values of the grape juices (mmol Trolox L−1) ranked as Alicante > Shiraz > Sultaniye > Carignan > Merlot > Chardonnay by CUPRAC, and Shiraz > Alicante > Merlot > Carignan ≥ Sultaniye > Chardonnay by ABTS/HRP and for skin extracts (mmol Trolox g−1), Carignan > Alicante > Shiraz > Merlot > Chardonnay > Sultaniye by CUPRAC, and Carignan > Shiraz > Alicante > Merlot > Chardonnay > Sultaniye by ABTS/HRP. The study demonstrated a strong correlation between phenolic composition and TAC values in grape samples, with anthocyanins as the predominant family contributing significantly to TAC. Varietal and intra-fruit differences in specific phenolic compounds were found to account for variations in observed TAC levels. Specifically, grape skin samples showed a more robust correlation between antioxidant capacity and total phenolic content (r = 0.986) than grape juices (r = 0.777). These findings underscore the considerable variation in antioxidant potential among grape varieties and emphasize the critical role of phenolic composition in the health-related benefits of grape consumption.

An Intelligent Mechanism to Detect Multi-Factor Skin Cancer.

Deep learning utilizing convolutional neural networks (CNNs) stands out among the state-of-the-art procedures in PC-supported medical findings. The method proposed in this paper consists of two key stages. In the first stage, the proposed deep sequential CNN model preprocesses images to isolate regions of interest from skin lesions and extracts features, capturing the relevant patterns and detecting multiple lesions. The second stage incorporates a web tool to increase the visualization of the model by promising patient health diagnoses. The proposed model was thoroughly trained, validated, and tested utilizing a database related to the HAM 10,000 dataset. The model accomplished an accuracy of 96.25% in classifying skin lesions, exhibiting significant areas of strength. The results achieved with the proposed model validated by evaluation methods and user feedback indicate substantial improvement over the current state-of-the-art methods for skin lesion classification (malignant/benign). In comparison to other models, sequential CNN surpasses CNN transfer learning (87.9%), VGG 19 (86%), ResNet-50 + VGG-16 (94.14%), Inception v3 (90%), Vision Transformers (RGB images) (92.14%), and the Entropy-NDOELM method (95.7%). The findings demonstrate the potential of deep learning, convolutional neural networks, and sequential CNN in disease detection and classification, eventually revolutionizing melanoma detection and, thus, upgrading patient consideration.

Used Oil Refining Process by Using Green Tea Waste for Floor Cleaner With An Addition of Pineapple Skin Extract

Used cooking oil is a waste that is produced every day and is increasing. Used cooking oil cannot be consumed again because it contains dangerous substances that will cause disease, but it also cannot be thrown away since it will pollute the environment. Therefore, it is necessary to process used cooking oil, one of which is purification using the adsorption method. The adsorption method for used cooking oil can be derived from green dregs because greens contain antioxidants which can reduce the content of dangerous substances in used cooking oil. In this study, we used variations in adsorbent mass (10 gr, 20 gr, 30 gr, 40 gr, and 50 gr) and stirring time (25 minutes, 45 minutes, 65 minutes, 86 minutes, and 105 minutes) to obtain the highest purification results. was the best and it was found that the adsorbent mass of 50 grams of green dregs and a stirring time of 105 minutes had the best results in being able to reduce the peroxide value, air content and free fatty acids. Next, the purified used cooking oil will be processed into floor cleaning liquid soap with the addition of 2 ml, 4 ml, 6 ml, 8 ml and 10 ml of pineapple peel extract. The results of the floor cleaning soap showed that the best results were 2 ml based on the alkaline number, pH and anti-bacterial test.

Characteristics of Cellulose Nanofibrils From Arabica Coffee Skin Prepared by the Acid Hydrolysis

Cellulosenanofibrils (CNF) is a new generation material that has high performance, good physics and medical properties and is a renewable material that has been developed from various sources using the acid hydrolysis method. CNF synthesis is generally obtained from logs that have a high amount of cellulose fiber. Cellulose nanofibrils (CNF) from arabica coffee skins have great potential to be developed as raw materials for medicines, which function as wound healing agents, surgical sutures, diet medicines, and skin softeners. CNF is produced from Arabica coffee skin through delignification, namely the removal of lignin and hemicellulose by extraction with alkali until α-cellulose is obtained, then CNF is synthesized through hydrolysis using dilute acid. From the coffee skin extraction results, a high cellulose yield was obtained, reaching above 24.30% and crystallinity reaching 79.60%. Hydrolysis by 10%, 12% and 15% HCl with a reaction time of 2 hours, the respective crystallinity was 80.66; 79.06; and 77.69%.

Phytochemical characterization of selected agro-waste extracts as kinetic inhibitors in methane hydrates formation

In this study of gas hydrate inhibition, the bio-active components (phytochemicals) and the influence of functional moieties and chemical structures on selected bio-inhibitors' performance were investigated by advanced analytical techniques. The agro-waste materials of interest are: orange mesocarp (Citrus sinensis (L)) extract (OME), red onion skin (Allium cepa) extract (ROSE), kolanut tesla (Cola acuminata) extract (KTE), coconut coir dusk (Cocos nucifera) extract (CCDE) and peanut skin (Arachis hypogea) extract (PSE). A CO2-enhanced supercritical fluid extraction (SFE) technique was used to extract the bioactive components from their parent materials. After the extraction, advanced analytical techniques including FTIR, NMR and HP-TLC with densitometry were used to identify and isolate functional groups, structurally characterize and quantify the bioactive compounds in the extracts primarily focusing on phenolic acids, flavonoids and tannins. A Bruker 500MZ NMR spectrometer and a CAMAG-semi-automatic HP-TLC system were used for the structural characterization and quantification respectively. Based on the number of anti-oxidants and radicals scavenging characteristics of the individual extracts' polyphenolic and tannin components, the expected hydrates inhibition capacities of the bio-extracts are in the magnitude: CCDE > ROSE > PSE > OME > KTE. The extracts are readily biodegradable and non-toxic and therefore do not pose ecological threat unlike PVP with only 31.50% biodegradation rate and may result in serious ecological risks in offshore environments. Lastly, the numbers of hydroxyl (OH) and meth-oxyl (MeoH) groups are the principal factors that influence the bio-inhibitors performance with hydroxyl group number being more important than that of the meth-oxyl group.

Development of pH response film based on potato starch/polyvinyl alcohol using Kyoho grape skin extract to monitor pork freshness

Development of <scp>pH</scp> response film based on potato starch/<scp>polyvinyl alcohol</scp> using Kyoho grape skin extract to monitor pork freshness

Microencapsulation of peanut skin polyphenols for shelf life improvement of sunflower seeds.

Derived from industrial processing waste, peanut skins contain polyphenols that delay oxidative food spoilage. However, these compounds are susceptible to light, heat, and oxygen exposure. Microencapsulation provides a solution by offering protection from these factors. The aim of this study was to evaluate the protective effect of peanut skin extract microcapsules on the chemical, microbiological, and sensory property and shelf life of sunflower seeds during storage. Five roasted sunflower seed samples were prepared: control (S-C); added with butylhydroxytoluene (S-BHT); coated with carboxymethyl cellulose (S-CMC); coated with CMC and the addition of peanut skin crude extract (S-CMC-CE); coated with CMC and the addition of microcapsules (S-CMC-M20). Sensory acceptability was determined using hedonic testing. Chemical (peroxide value, conjugated dienes, hexanal and nonanal content, and fatty acid profile), microbiological, and descriptive analyses were carried out on samples stored for 45 days at room temperature. Shelf life was calculated using a simple linear regression. All samples were microbiologically fit for human consumption and accepted by consumer panelists, scoring above five points on the nine-point hedonic scale. S-CMC-M20 exhibited the lowest peroxide value (6.59meqO2/kg) and hexanal content (0.4µg/g) at the end of the storage. Estimated shelf life showed that S-MC-M20 (76.3 days) extended its duration nearly ninefold compared to S-C (8.3 days) and doubled that of S-CMC-CE (37.5 days). This indicates a superior efficacy of microencapsulated extract compared to its unencapsulated form, presenting a promising natural strategy for improving the shelf life of analogous food items. PRACTICAL APPLICATION: Incorporating peanut skin extract microcapsules in coating sunflower seeds presents a promising strategy to extend the shelf life of lipid-rich foods, capitalizing on the antioxidant properties of polyphenols. This innovative approach not only enhances nutritional quality but also addresses sustainability concerns by repurposing agro-industrial byproducts, such as peanut skins. By meeting consumer demand for functional foods with added health benefits, this technique offers potential opportunities for the development of novel, value-added food products while contributing to circular economy principles and waste management efforts.

Risk Perception: Chemical Stimuli in Predator Detection and Feeding Behaviour of the Invasive Round Goby Neogobius melanostomus.

The round goby Neogobius melanostomus is a notoriously invasive fish originating from the Ponto-Caspian region that in recent decades has successfully spread across the globe. One of its primary impacts is direct predation; in addition, when entering new ecosystems, the round goby is likely to become a food resource for many higher native predators. However, little is known either about the indirect effects of predators on the round goby as prey or its feeding behaviour and activity. The non-consumptive effect of the presence of higher native predators presumably plays an important role in mitigating the impact of non-native round gobies as mesopredators on benthic invertebrate communities, especially when both higher- and mesopredators occupy the same habitat. We tested the food consumption probability and gut evacuation rates in round gobies in response to chemical signals from a higher predator, the European eel Anguilla anguilla. Gobies were placed individually in experimental arenas equipped with shelters and exposed to water from a tank in which (a) the higher predator had actively preyed on a heterospecific prey, earthworms Lumbricus sp. (the heterospecific treatment; HS); (b) the higher predator had fed on round gobies (the conspecific treatment; CS); or (c) the water was provided as a control treatment (C). To ensure exposure to the chemical stimuli, this study incorporated the application of skin extracts containing damaged-released alarm cues from the CS treatment; distilled water was used for the remaining treatments. No significant differences were observed in either the food consumption probability or gut evacuation rate in the tested treatments. Despite the lack of reaction to the chemical stimuli, round gobies did exhibit high evacuation rates (R = 0.2323 ± 0.011 h-1; mean ± SE) in which complete gut clearance occurred within 16 h regardless of the applied treatment. This rapid food processing suggests high efficiency and great pressure on resources regardless of the presence or not of a higher predator. These findings hint at the boldness of round gobies, which did not exhibit any pronounced threat sensitivity. This would seem to suggest great efficiency in food processing and a potential competitive advantage over local native species when colonising new ecosystems, irrespective of the presence of native predators. Our study did not detect any non-consumptive effect attributable to the higher predator, given that the feeding activity of the invasive round goby was not altered.

Proanthocyanidins isolated from lotus seed skin mitigate glycolipid metabolism disorder through the p38/Nrf2/NF-κB signaling pathway.

Lotus seed skin extract is rich in flavonoids, making it a promising candidate for developing health products. In a previous study, we found that proanthocyanidins from lotus seed skin, particularly proanthocyanidin B1 (PB1), can indirectly activate the Nrf2 signaling pathway, exerting an antioxidant effect. In this study, we isolate proanthocyanidins from lotus seed skin (PLS) using ethanol extraction and RP-HPLC identification, and investigate its effects on glycolipid metabolism both in vivo and in vitro. Our results demonstrate that PLS reduces body weight in high-fat diet (HFD) mice by decreasing feed efficiency. PLS also normalizes serum glucose, insulin secretion, glycosylated hemoglobin (HbA1c), and intraperitoneal glucose tolerance (IPGTT). Furthermore, PLS significantly improves blood lipid parameters and inhibits the expressions of six proinflammatory factors, including IL-1α, IL-1β, IL-3, IL-6, IFN-γ and TNF-α in HFD mice. Additionally, analysis of fresh liver tissues reveals that PLS and PB1 induce the expressions of antioxidant proteins such as HO-1 and NQO1 by activating the p38-Nrf2 signaling pathway and inhibiting the NF-κB signaling pathway. In conclusion, proanthocyanidins from lotus seed skin regulate glycolipid metabolism disorders by targeting the p38/Nrf2/NF-κB signaling pathway. Our study offers a new approach for the high-value comprehensive utilization of lotus seed skin by-products and precise dietary intervention for metabolic syndrome.

Performance evaluation of glutaraldehyde-modified red onion skin extract as oilfield scale inhibitors

Scale deposition occurs due to changes during injection operations and the mixing of incompatible brines. Scale inhibitors are used to mitigate such occurrences. The inhibition efficiency of the glutaraldehyde-ROSE resin (ROG) was evaluated in synthetic brines containing CaSO4, BaSO4, and CaCO3 under static conditions according to NACE standard methods. The formulated scale inhibitor was compatible with the brine and thermally stable. The inhibition studies of ROG revealed optimal inhibition of 89% at 80 ppm and 58% at 100 ppm at 90 °C and 22 h, respectively, for BaSO4 and CaCO3 scales, while for CaSO4 scales, optimal inhibition of 67% was observed at 100 ppm, 71 °C, and 22 h. On comparison, the Commercial Scale Inhibitor (CSI) showed optimal inhibition of 97% at 100 ppm and 94% at 80 ppm at 71 °C and 22 h, respectively, for BaSO4 and CaSO4 scales, while for CaCO3 scales, optimal inhibition of 98% was observed at 80 ppm, 90 °C, and 22 h, respectively. This indicates that ROG efficiently mitigated the formation of CaSO4, BaSO4, and to some reasonable extent, CaCO3 scales, and its inhibition performance compared favorably with the CSI, thus unveiling its potential for consideration as a green oilfield scale inhibitor.

Identifying toxic effects and metabolic perturbations of Duttaphrynus melanostictus skin extracts in human erythrocytes.

Skin secretions of toads are widely used in medicine all over the world for their antiviral, anti-infective, and cardiotonic properties. Because these secretions are mostly employed to combat blood parasite infection, it is important to understand their potential toxic effects on human erythrocytes. Therefore, the objective of the current investigation was to elucidate the effects of Duttaphrynus melanostictus (Schneider) skin extracts on the physiology of human erythrocytes. Toads captured from their natural habitat were separated into three groups according to their body size. Hydroalcoholic extracts of toad skin were prepared by reflux heating. These extracts were then evaluated for their hemolytic and hemoglobin denaturation potential. The effects of the extracts on cytosolic and membrane-bound enzymes of human erythrocytes were assessed. The hemolysis and hemoglobin denaturation caused by these extracts correlated positively with the respective toad sizes. Extracts from medium and large toads led to increased osmotic fragility even at near iso-osmotic concentrations. Biochemical analysis of hemolysate showed that the treatment induced a shift of metabolic flux toward the glutathione pathway. Analysis of membrane-bound enzymes revealed a significant decrease in the activity of Na+/K+ ATPase and acetylcholinesterase. SDS-PAGE analysis of the erythrocyte membrane did not show the band of tropomodulin for the cells treated with 1000 𝜇g/ml extract from large toads. In conclusion, the present study demonstrates that the toxicity of toad skin secretions aggravates with the size of the animal and interferes with the physiology of human erythrocytes, leading to their membrane disruption and rapid lysis.

Epidermal club cells in the cardinal tetra (Paracheirodon axelrodi): Presence, distribution, and relationship to antipredator behavior

Epidermal club cells (ECCs) are present in many species of teleost fish. In an attempt to justify their presence in the epidermis of fish, they have been associated with numerous functions. One proposed function is communication with conspecifics during a predation event, as these cells may passively release substances upon rupture, which may occur during predation. We identified the presence and distribution of ECCs in the body skin of adult cardinal tetra, Paracheirodon axelrodi (Schultz, 1956) and analyzed the animal’s behavioral response to conspecific skin extract in a laboratory setting. The identification and distribution of ECCs in the epidermis of the animals were confirmed by conventional histology and immunohistochemistry. Our results demonstrated that: ECCs are present in the skin of the entire body; a high density is observed in the dorsal side from head to tail, in the insertion of the fins and in the epidermis covering them; and ventral distribution is less extensive and more dispersed than dorsal distribution. Treatment of P. axelrodi specimens with skin preparations of conspecifics resulted in behavioral changes in the animals: they showed erratic swimming movements, they showed avoidance of the area of stimulus application and they decreased the time spent moving. Overall, these results allow us to conclude that P. axelrodi possesses ECCs throughout the body, with a greater presence in areas of high exposure to predation events (dorsal area and fins). Animals exposed to conspecific skin extract showed a significant increase in behaviors described as anti-predatory in other species. This supports the hypothesis that ECCs may be the origin of chemical alarm cues that are passively released when skin damage occurs, alerting the rest of the group to the risk of predation.

POTENTIAL OF DAYAK ONION SKIN (ELEUTHERINE PALMIFOLIA) EXTRACT AS AN ALTERNATIVE INDICATOR FOR ACID BASE TITRATION PRACTICUM

Synthetic indicators such as phenolphthalein are used during acid-base titrations to determine the end point of the titration. These indicators are not environmentally friendly and the price is high. To overcome this, it is necessary to study the potential of natural indicators available in the environment, one of which was Dayak onion skin which has not been utilized after the tubers have been taken as an anti-cancer herbal medicine. The aim of this research was to determine the potential of Dayak onion skin (Eleutherine Palmifolia) as a natural indicator in acid-base titrations. The sampling collection of Dayak onions was done randomly in the city of Palangka Raya, Central Kalimantan. The method used in this study employed experimental techniques in the chemistry laboratory of FKIP ULM with the following steps: 1) Maceration of smoothed Dayak onion skin with 96% ethanol for 1, 2 and 3 days 2) Qualitative test of anthocyanin, color test with buffer pH 1-14, 3) Absorption measurement with a UV-Vis spectrophotometer at a wavelength of 200 - 400 nm, 4) Application of the extract as an indicator in acid-base titrations. The results showed that the optimum maceration time was on day 3 with an absorption of 4,520 at a wavelength of 380 nm. The application on the HCl – NaOH titration with a titration end point volume of 9.11 mL showed a color change from yellow to straw yellow, while the comparison indicator PP had a volume change of 8.57 mL with a color change from colorless to pink. The CH3COOH – NaOH titration gave a result of 11.43 mL and the PP indicator was 11.01 mL. For the NaHCO3 – HCl titration, the end point volume of the titration was 9.93 mL with a straw yellow – yellow color change and the MO indicator comparison was 10.27 mL with an orange – red color change. From the results of this research, there was a significant color change at the end point of the titration, so it can be stated that Dayak onion skin extract had the potential to be an alternative indicator in acid-base titration practice so that it can be a solution in reducing chemical pollution in the environment.

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.