Search Results (37)

Aloin, a kind of active phenolic component, is sourced from Aloe vera. Recently, the determination of aloin has received enormous attention, owing to its positive performance (including anti-tumor, antibacterial, detoxification, liver protection, anti-stomach damage, and skin protection activities) and painful side effects (increased carcinogenicity caused by excessive use of aloin) impacting human health. This investigation was inspired by the good fluorescence properties of carbon dots (CDs); CD-based sensors have aroused a great deal of interest due to their excellent sensitivity and selectivity. Thus, it is of great significance to develop novel CD-based sensors for aloin determination. Herein, N,F-CDs were designed and synthesized through a convenient hydrothermal strategy; the synthesized N,F-CDs possessed good fluorescence performance and a small particle size (near 4.3 nm), which demonstrated the successful preparation of N,F-CDs. The resulting N,F-CDs possessed a large Stokes shift and could emit a highly stable green fluorescence. The fluorescence of the N,F-CDs could be effectively quenched by aloin through the inner filter effect. Furthermore, the synthesis procedure was easy to operate. Finally, the N,F-CD-coated test strips were fabricated and combined with a miniaturized fluorimeter for the fluorescence detection of aloin via the inner filter effect for the first time. The N,F-CD-coated test strips were fabricated and used for the fluorescence sensing of aloin, and the results were compared with a typical ultraviolet (UV) method. The N,F-CD-coated test strips exhibited high recovery (96.9~106.1%) and sensitivity (31.8 nM, n = 3), good selectivity, low sample consumption (1 μL), high speed (5 min), good stability, and anti-interference properties. The results indicate that N,F-CD-coated test strips are applicable for the quantitative determination of aloin in bovine serum, orange juice, and urine samples. Full article

Postharvest losses and limited physiological knowledge restrict the conservation and year-round availability of underutilized crops such as Dioscorea trifida. This study characterized the postharvest behavior of Colombian purple D. trifida tubers and evaluated low-cost, GRAS-status technologies to improve storage performance in smallholder production systems. Tubers were stored for 34 days at ambient conditions (20 °C, 90% RH) and compared with treatments including cold storage, calcium pretreatments combined with Aloe vera-based coatings, and short-duration hot water immersion. Over storage, total carbohydrates increased, while potassium remained at substantial levels until the final day. Weight loss and respiration declined steadily, and sprouting was absent, suggesting extended endodormancy in this genotype. Major deterioration causes observed upon reception included fragmentation, insect damage, and surface molds, highlighting the importance of improved sanitation and mechanical protection during harvest, early postharvest stages, and transportation. Edible coatings enhanced antioxidant activity and increased malic and succinic acid concentrations. Cold storage at 3 °C reduced weight loss more effectively than storage at 12 or 20 °C, although citric acid accumulation was greater at the latter temperature. Among all treatments, immersion at 55 °C for 5 min was the most promising, offering a scalable, low-input option to extend shelf life in neglected yam species. Full article

Growing health and environmental concerns have intensified the search for natural antioxidants to replace synthetic alternatives to prevent spoilage of seafood. Long-term intake of synthetic antioxidants has been linked to liver toxicity, reproductive issues, and cancer risks in animals. This study therefore evaluates the efficacy of Aloe vera gel (AVG) as a natural antioxidant in preserving the quality of sea bass (Dicentrarchus labrax, Linnaeus 1758) slices during cold storage at 4 ± 1 °C for 13 days. Sea bass slices were coated with 100% and 75% AVG and analyzed for physical (color and texture), chemical (pH, TVB-N, TBARS, and PV), and sensory changes. Results showed that AVG significantly reduced lipid oxidation, as indicated by lower peroxide (PV) and thiobarbituric acid reactive substances (TBARS) values in treated samples compared to controls. While sensory, color, and texture parameters remained consistent across all groups, 75% AVG-coated slices extended the shelf life by four days, and the 100% AVG treatment achieved a two-day extension, based on TVB-N values. These findings highlight AVG’s potential as a natural, eco-friendly alternative to synthetic antioxidants for aquatic product preservation. Full article

Aloe vera is well known for its biological properties as a bioflavonoid anti-inflammatory and antibacterial agent. It has been used frequently in the food sector as a food coating due to its hygroscopic properties and as an ingredient in the lucrative cosmetic industry. Studies have also included aloe vera as an eco-friendly green solution based on these properties. The current research focuses on the use of aloe vera gel in printing pastes as an alternative sustainable solution to synthetic thickeners, evaluating its wet performance and ease of fabric stitching, and has been inspired by studies that similarly used this substance and measured its effect on the fabric’s coefficient of friction and antimicrobial action. In the current study, printing pastes with natural colourants, such as saffron, curcumin, and annatto, and aloe vera gel thickener derived from natural leaves from Crete increased the fabric’s mechanical resistance to abrasion compared to the untreated pastes. The measured performance did not differ substantially from prints with traditional synthetic pastes, hence tolerating the substitution with the non-contaminant variant. The enhanced resistance to abrasion and wear extends the fabric’s serviceable life and resulting garments, decreasing the need for high industry processing volumes and, as a result, reducing pollution. The resistance to wear was evaluated using the dominant method in textile testing of the Martindale apparatus, which measured the cycles to failure, weight loss, and general appearance deterioration using the official photographic standards. Full article

The objective of this study was to evaluate the impact of harvesting stages (turning-color fruit and light red color) and postharvest treatments (distilled water, hot water at 35 °C, 10% Aloe vera, 2% CaCl₂, 5% Mint, and 5% Catnip) for 5 min on the quality and storability of tomato fruits cv. Sangaw stored at 10 ± 1 °C and a relative humidity of 90%–95% for 20 days. Fruit harvested at the turning-color fruit stage presented significantly lower weight loss, greater firmness, and higher amounts of vitamin C, total phenol, and calcium (3.22%, 1118.31 g mm/s, 15.83 mg 100 g⁻¹, 95.49 mg 100 mL⁻¹ FW, and 0.14%, respectively). However, the tomatoes harvested from the light red color fruit stage presented the highest contents of total soluble sugars, total sugars, and lycopene (4.36%, 3.99%, and 41.49 mg kg⁻¹, respectively). Notably, the postharvest treatment of tomato fruits with 2% CaCl₂ significantly decreased weight loss and resulted in greater firmness, pH, total sugar, total phenol, and calcium contents (3.90%, 1212.39 g mm/s, 4.83, 3.85%, 95.60 mg 100 mL⁻¹ FW, and 0.18%, respectively) than the control. Hence, coating with 10% Aloe vera resulted in the highest amount of total soluble solids and the highest amount of vitamin C. Tomato picked at the turning-color fruit stage and immersed in 5% Mint significantly lowered the loss of fruit weight, increased the total titratable acidity, and had the lowest content of lycopene. Additionally, the fruits harvested at the same stage and immersed in 2% CaCl₂ retained greater firmness, total phenol content, and calcium content. On the other hand, fruits harvested in the light red stage and dipped in 5% Mint presented the highest total soluble sugars and total sugar contents. Finally, the harvested tomato fruits coated with 10% Aloe vera retained a relatively high level of vitamin C, indicating the storage life and quality of the tomato fruits. Full article

Fig is a widespread crop in southern Italy, highly valued for its sweet flavor. However, its consumption as a fresh product is limited to three to four days after harvest because of its high susceptibility to quality loss and microbial contamination. The combined use of low temperature and a modified atmosphere is the traditional preservation method. However, several studies have shown that the use of Aloe arborescens or vera and O. ficus-indica (OFI) mucilage as an edible coating could reduce the microbial load and water loss, respectively. Therefore, our study aimed to evaluate the synergistic effects of Aloe gel (AG) and O. ficus-indica mucilage (OM) on the quality and safety of two fig cultivars, ‘San Giovanni’ and ‘Melanzana’, during cold storage at 4 °C. The main results showed the effectiveness of edible coatings on both fig cultivars. An AG coating significantly reduced the microbial load, while the OM treatment showed the ability to preserve firmness and reduce weight loss. In addition, the combined OM + AG treatment showed the same effects as the individual coating formulations, also improving visual appearance. Thus, the use of the synergetic coating formulation could be a natural way to reduce the microbial load, extending fresh fig fruit’s shelf life. Full article

This study investigated the impact of chitosan (CH, 1%) and aloe vera gel (AL, 30%) edible coatings on the preservation of blue honeysuckle quality during a 28-day storage at −1 °C. Coating with CH, AL, and CH+AL led to notable enhancements in several key attributes. These included increased firmness, total soluble solids, acidity, pH, and antioxidant capacity (measured through DPPH, ABTS, and FRAP assays), as well as the preservation of primary (ascorbic acid) and secondary metabolites (TPC, TAC, and TFC). The TAC and TFC levels were approximately increased by 280% and 17%, respectively, in coated blue honeysuckle after 28 d compared to uncoated blue honeysuckle. These coatings also resulted in reduced weight loss, respiration rate, color, abscisic acid, ethylene production, and malondialdehyde content. Notably, the CH+AL treatment excelled in preserving secondary metabolites and elevating FRAP-reducing power, demonstrating a remarkable 1.43-fold increase compared to the control after 28 days. Overall, CH+AL exhibited superior effects compared to CH or AL treatment alone, offering a promising strategy for extending the shelf life and preserving the quality of blue honeysuckle during storage. Full article

Food bioactive packaging has received increasing attention from consumers and the food industry for its potential to reduce food waste and environmental issues. Several materials can be used to produce edible films/coats; however, bio-based, cost-effective, and sustainable coatings have gained a high reputation these days. For instance, Aloe vera gel (AV) is a promising bio-based material for edible coatings and films; therefore, the present study aimed to investigate the film-forming abilities of AV and Chitosan (CH) combination as a potential active food packaging material. The physicochemical and mechanical characteristics of formed films of various combinations were prepared at different concentrations, i.e., CH (0.5% w/v), AV (100%), CH:AV (75:25), and CH:AV (60:40). The results showed significant differences among all the prepared edible films wherein these differences were mainly on account of incorporating AV gel. The rheological and antioxidant properties of the formulations improved with the inclusion of AV gel. The films composed of CH:AV (60:40) positively affected the water solubility, thermal properties, and water vapour permeability of the edible films. The X-ray Diffraction (XRD) and Scanning electron microscopy (SEM) results showed that the films composed of CH:AV, (60:40) were amorphous and had smooth morphology. Further, the edible film solutions were applied to fresh figs (Ficus carica) to investigate their role in preserving fruits during storage. A significant reduction in microbial growth was found in coated fruits after 28 days of cold storage. The films composed of CH and AV showed overall improved results compared to the CH (0.5%, w/v). Therefore, the used formulations (CH:AV, 60:40) can form a sustainable film that has the potential to be utilized for fresh product preservation to maintain its quality and shelf life. Full article

The effectiveness of an alginate/chitosan nanomultilayer coating without (NM) and with Aloe vera liquid fraction (NM+Av) was evaluated on the postharvest quality of tomato fruit at 20 °C and 85% relative humidity (RH) to simulate direct consumption. Both nanomultilayer coatings had comparable effects on firmness and pH values. However, the NM+Av coating significantly reduced weight loss (4.5 ± 0.2%) and molds and yeasts (3.5–4.0 log CFU g⁻¹) compared to uncoated fruit (16.2 ± 1.2% and 8.0 ± 0.0 log CFU g⁻¹, respectively). It notably lowered O₂ consumption by 70% and a 52% decrease in CO₂ production, inhibiting ethylene synthesis. Visual evaluation confirmed NM+Av’s efficacy in preserving the postharvest quality of tomato. The preservation of color, indicated by the Minolta color (a*/b*) values, demonstrated NM+Av’s ability to keep the light red stage compared to uncoated fruit. The favorable effects of NM+Av coating on enhancing postharvest quality indicates it as a potential alternative for large-scale tomato fruit preservation. Full article

Sapota is a significant climacteric fruit with a limited shelf life. Therefore, it is necessary to employ the specific treatments that could prolong the shelf life and preserve the quality of sapota fruits. The current research compared the effect of aloe vera gel (AV) 100%, AV 100% + 5 µL/20 mL ajwain oil (AV + AO), and AV 100% + 5 µL/20 mL oregano oil (AV + OO) on sapota fruits at ambient temperature. Commercial fungicide (carbendazim)-treated (CT) fruits were also investigated. The CT-treated and the combined treatments of AV 100% + 5 µL AO and AV 100% + 5 µL OO considerably reduced the decay incidence and weight loss in sapota fruits. Additionally, the CT-treated, AV 100% + 5 µL AO-treated, and AV 100% + 5 µL OO-treated fruits have higher titratable acidity, ascorbic acid, total soluble solids, and phenol, flavonoid, and antioxidant contents than the AV 100% and control fruits. The outcome of this study showed that the CT-treated, AV 100%+ 5 µL AO-treated, and AV 100% + 5 µL OO-treated fruits maintained the overall attributes of sapota fruits. Therefore, in the future, the combination of AV 100% + 5 µL AO and AV 100% + 5 µL OO coatings could be a promising substitute for commercial fungicide to treat sapota fruits. Full article

Strawberry (Fragraria x ananassa Duch) cv. Tochiotome is nutrient rich. However, it has a short shelf life, especially at room temperature. Coating is one of the methods used to prolong fruit shelf life. Coating materials, such as nano chitosan (NC) and Aloe vera (AV) gel, are edible and safe to consume. The objective was to analyze the interaction between AV gel and NC concentrations and determine the optimal concentration to improve the quality of strawberries at room temperature. This experiment used a factorial randomized block design with treatments of NC (0, 0.5, and 1%) and AV gel (0, 25, and 50%). The results showed an interaction between AV gel and NC concentrations for all variables. The optimum concentrations to improve the fruit quality of strawberries cv. Tochiotome were 25% AV gel with 1% NC, which increased the value by more than twofold compared with the control (no AV gel and NC) until four days after storage. The fruit quality characteristics were fruit hardness (6.57 N), weight loss (1.23%), titratable acidity (0.74 mL), total phenolic (1.79 µg GAE/FW), total flavonoid (29.85 mg QE/g), vitamin C concentration (43.83 mg/100 g), and shelf life (4.66 days). More than 1% NC may enhance quality. In conclusion, AV and NC are a potential treatment for improving the postharvest quality of strawberry. Full article

Climacteric rise in the rate of respiration and ethylene production in harvested persimmon (Diospyros kaki) fruits leads to early onset of fruit tissue senescence. Therefore, this study was carried out to maintain the quality of stored persimmons by using edible coatings. For this purpose, Aloe vera gel was combined with food hydrocolloids, gum arabic or tragacanth gum, and applied on persimmon fruits that were stored for 20 days at 20 ± 1 °C and 80–85% RH. Biocomposite coatings, compared to control, remarkably reduced weight loss, decay incidence, respiration rate, ethylene production, electrolyte leakage, malondialdehyde, H₂O₂ and superoxide anion content in stored fruits. The use of composite coatings inhibited colour change by reducing the accumulation of total carotenoids, maintained higher antioxidative enzymes activity and suppressed the activity of cell wall degrading enzymes, resultantly preserving cell wall components. Composite coated fruits exhibited the least change in biochemical attributes and higher sensory scores in comparison with non-coated fruits at the end of the storage period. In conclusion, Aloe vera gel/gum arabic was the most effective coating treatment before storing persimmons. Full article

The COVID-19 pandemic has increased the need for developing disinfectant surfaces as well as reducing the spread of infections on contaminated surfaces and the contamination risk from the fomite route. The present work reports on the antiviral activity of coatings containing ZnO particles obtained by two simple synthesis routes using Aloe vera (ZnO-aloe) or cassava starch (ZnO-starch) as reaction fuel. After detailed characterization using XRD and NEXAFS, the obtained ZnO particles were dispersed in a proportion of 10% with two different waterborne acrylic coatings (binder and commercial white paint) and brushed on the surface of polycarbonates (PC). The cured ZnO/coatings were characterized by scanning electron microscopes (SEM) and energy-dispersive X-ray spectroscopy (EDS). Wettability tests were performed. The virucidal activity of the ZnO particles dispersed in the waterborne acrylic coating was compared to a reference control sample (PC plates). According to RT-PCR results, the ZnO-aloe/coating displays the highest outcome for antiviral activity against SARS-CoV-2 using the acrylic binder, inactivating >99% of the virus after 24 h of contact relative to reference control. Full article

In the present investigation, Aloe vera gel (AVG)-based edible coatings enriched with anthocyanin were prepared. We investigated the effect of different formulations of aloe-vera-based edible coatings, such as neat AVG (T1), AVG with glycerol (T2), Aloe vera with 0.2% anthocyanin + glycerol (T3), and AVG with 0.5% anthocyanin + glycerol (T4), on the postharvest quality of fig (Ficus carica L.) fruits under refrigerated conditions (4 °C) for up to 12 days of storage with 2-day examination intervals. The results of the present study revealed that the T4 treatment was the most effective for reducing the weight loss in fig fruits throughout the storage period (~4%), followed by T3, T2, and T1. The minimum weight loss after 12 days of storage (3.76%) was recorded for the T4 treatment, followed by T3 (4.34%), which was significantly higher than that of uncoated fruit (~11%). The best quality attributes, such as the total soluble solids (TSS), titratable acidity (TA), and pH, were also demonstrated by the T3 and T4 treatments. The T4 coating caused a marginal change of 0.16 in the fruit titratable acidity, compared to the change of 0.33 in the untreated fruit control after 12 days of storage at 4 °C. Similarly, the total soluble solids in the T4-coated fruits increased marginally (0.43 °Brix) compared to the uncoated control fruits (>2 °Brix) after 12 days of storage at 4 °C. The results revealed that the incorporation of anthocyanin content into AVG is a promising technology for the development of active edible coatings to extend the shelf life of fig fruits. Full article

Aloe vera is widely used to manufacture medicinal products, cosmetics, and hair treatments. The polysaccharide components in A. vera gel can be used as ingredients for edible films or coatings. The edible film can also be applied to fresh fruits and vegetables using the coating principle. Tomatoes are one of the fruit commodities that can be maintained in terms of quality during storage using an edible coating. This study aims to determine the effect of an edible coating made from A. vera on tomatoes’ physical, chemical, and organoleptic properties during storage. The A. vera gel was prepared and used for coating the tomatoes, and the tomatoes were then stored for twelve days. The analysis was conducted every three days, and a comparison with non-coated tomatoes was performed for tomatoes’ physicochemical and organoleptic properties. The results show that the application of A. vera as a coating agent could prolong the shelf life of tomatoes, as described in the ability to decrease moisture content and weight loss. The coated tomatoes had lower titratable acidity value, pH, and total soluble solid contents than the non-coated tomatoes. From the organoleptic test, the non-coated tomatoes were preferred by the panelists for color, but the glossiness, skin appearance, and texture of the coated tomatoes were preferred. The coating process could maintain the hardness of tomatoes and prevent the production of phenolic compounds, flavonoids, and lycopene; thus, the antioxidant activity could be conserved. Full article