Arsenic (As) contamination in soil presents significant challenges to plant growth and development, impacting agricultural productivity, food safety, ecosystem stability, and human health. This study investigates the effects of As toxicity on the medicinal plant Ocimum basilicum L. cultivar CIM-Saumya by assessing the impact of varying As concentrations (1, 5, 10, and 25 mg kg-1 of soil) on various physio-biochemical and microscopic parameters. Controlled experiments were conducted to assess the photosynthetic rate, gas exchange, and the activities of carbonic anhydrase (CA), Rubisco, and nitrate reductase (NR) enzymes. In addition, the concentrations of non-enzymatic antioxidants (proline, flavonoids, and phenolic compounds) and enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) were analyzed. Alterations in glandular trichomes, essential oil (EO) content, and composition were also evaluated. Confocal laser scanning microscopy (CLSM) was utilized to examine root cell viability and detect reactive oxygen species (ROS). Our results revealed that As exposure significantly inhibited physio-biochemical activities in O. basilicum, with low As concentrations (1 mg kg-1) enhancing EO content by 18.75 %. However, higher As concentrations (25 mg kg-1) induced oxidative stress, evidenced by increased malondialdehyde (MDA), ROS accumulation, reduced trichome size and density, and smaller stomatal apertures. The highest As concentration resulted in a 53.12 % reduction in EO content. These findings demonstrate that O. basilicum exhibits differential responses to As stress, with low concentrations enhancing EO production, while high concentrations cause oxidative damage and reduced EO content, providing insights into the plant's adaptive strategies and potential alterations in its aroma and therapeutic properties under As stress.
Genera Pseudomonas and Xanthomonas include bacterial species that are etiological agents of several diseases of major vegetable crops, such as tomato, pepper, bean, cabbage and cauliflower. The bacterial pathogens of those genera may cause severe crop damage, leading to symptoms like leaf spots, wilting, blights, and rotting. These plant pathogens can affect propagation materials and spread rapidly through plant tissues, contaminated soils, or water sources, making them challenging to control using conventional chemical products alone. Biopesticides, such as essential oils (EOs), are nowadays studied, tested and formulated by employing nano- and micro-technologies as innovative biological control strategies to obtain more sustainable products using less heavy metal ions. Moreover, there is a growing interest in exploring new biological control agents (BCAs), such as antagonistic bacterial and fungal species or bacteriophages and understanding their ecology and biological mechanisms to control bacterial phytopathogens. These include direct competition for nutrients, production of antimicrobial compounds, quorum quenching and indirect induction of systemic resistance. Optimisation of the biocontrol potential goes through the development of nanoparticle-based formulations and new methods for field application, from foliar sprays to seed coatings and root inoculation, aimed to improve microbial stability, shelf life, controlled release and field performance. Overall, the use of biological control in horticultural crops is an area of research that continues to advance and shows promising potential. This review aims to provide an in-depth exploration of commercially accessible biocontrol solutions and innovative biocontrol strategies, with a specific focus on the management of bacterial diseases in vegetable crops caused by Pseudomonas and Xanthomonas species. In this article, we highlighted the advancements in the development and use of EOs and other BCAs, emphasizing their potential or shortcomings for sustainable disease management. Indeed, despite the reduced dependence on synthetic pesticides and enhanced crop productivity, variable regulatory frameworks, compatibility among different BCAs, and consistent performance under field conditions are among the current challenges to their commercialization and use. The review seeks to contribute valuable insights into the evolving landscape of biocontrol in vegetable crops and to provide guidance for more effective and eco-friendly solutions against plant bacterial diseases.
Bio-active packaging films from cellulose acetate incorporated with cypress essential oil (Cyp) have been developed. Thus, cellulose acetate (CA), which is a biodegradable and renewable polymer has been used as an alternative to petroleum-based polymers. Cellulose acetate films were prepared via a solvent casting method incorporating 0, 10, 30, and 60% (w/w) of Cyp. The purpose was to evaluate the possible changes caused by the Cyp on the properties of the packaging films. Different methods and technics have been used to characterize these films. The antibacterial and antioxidant properties of the films were also analyzed. FTIR and XRD analysis indicated that Cyp was homogenously distributed in the films. Meanwhile, TGA analysis demonstrated that the addition of Cyp had an impact on thermal-oxidative properties of the films. The CA/Cyp films showed excellent biodegradability in soil after 60 days, with a percentage loss of 87.07% by mass, and improved mechanical properties with tensile strength and elongation-at-break of 8.1 +/- 0.2 MPa and 16.6 +/- 0.2%, respectively. Water absorption and water solubility values for CA/Cyp films ranged from 76.62 +/- 0.91% to 21.95 +/- 0.57% and from 1.29 +/- 0.35 to undetectable levels, respectively. The results displayed that antibacterial activity against Escherichia coli and Staphylococcus aureus increased as the percentage of Cyp increased in the cellulose acetate films. Moreover, the free radical scavenging activity of cellulose acetate films was improved by increasing the Cyp concentration. These results indicate that cellulose acetate films containing a low-cost essential oil like Cyp have potential for use as active packaging for foods.
PurposeThe present work aims to prepare biocomposites blend based on linear low density polyethylene/ starch without using harmful chemicals to improve the adhesion between two phases. Also, the efficiency of essential oils as green plasticizers and natural antimicrobial agents were evaluated.Design/methodology/approachBarrier properties and biodegradation behavior of linear low density polyethylene/starch (LLDPE/starch) blends plasticized with different essential oils including moringa oleifera and castor oils wereassessed as a comparison with traditional plasticizer such as glycerol. Biodegradation behavior forLLDPE/starch blends was monitored by soil burial test. The composted samples were recovered then washed followed by drying, and weighting samples after 30, 60, and 90 days to assess the change in weight loss. Also, mechanical properties including retention values of tensile strength and elongation at break were measured before and after composting. Furthermore, scanning electron microscope (SEM) was used to evaluate the change in the morphology of the polymeric blends. In addition to, the antimicrobial activity of plasticized LLDPE/starch blends films was evaluated using a standard plate counting technique.FindingsThe results illustrate that the water vapor transition rate increases from 2.5 g m-2 24 h-1 for LLDPE/5starch to 4.21 g m-2 24 h-1 and 4.43 g m-2 24 h-1 for castor and moringa oleifera respectively. Also, the retained tensile strength values of all blends decrease gradually with increasing composting period. Unplasticized LLDPE/5starch showed highest tensile strength retention of 91.6% compared to the other blends that were 89.61, 88.49 and 86.91 for the plasticized LLDPE/5starch with glycerol, castor and M. oleifera oils respectively. As well as, the presence of essential oils in LLDPE/ starch blends increase the inhibition growth of escherichia coli, candida albicans and staphylococcus aureus.Originality/valueThe objective of this work is to develop cost-effective and environmentally-friendly methods for preparing biodegradable polymers suitable for packaging applications.
In this study, starch (ST), chitosan (CH), spider silk (SW), and their hybrid composite bioplastics were fabricated and examined for physicochemical and mechanical properties. The essential oils (EOs) of Rosmarinus officinalis were encapsulated to enhance their biological application. The prepared composite films were characterized using various spectroscopic techniques such as XRD, SEM, GCMS-, UV-VIS, TGA, and FTIR spectroscopy. The antimicrobial activity of the prepared film was tested against S. aureus bacterial and C. albican fungal strains which showed a greater zone of inhibition for the composite film encapsulated with EOs. The biodegradability of the synthesized film was evaluated for 60 days in soil under laboratory conditions. The composite film containing spider web and essential oil significantly improved mechanical properties. The physicochemical results, such as moisture, solubility, swelling, transmittance, opacity, and water vapor permeability, of the prepared bioplastic were comparable with those of the control plastic. The EO-based film had greater antioxidant activity against DPPH, hydrogen peroxide, and phosphomolybdenum assays, with an inhibition range of 60-70 %. The addition of spider web and essential oil to the chitosan/ starch film significantly increased the shelf life of injera and tomatoes for 7 and 10 days, respectively for the EO-based film. The biodegradability of the synthesized film has shown a great reduction in the weight and growth of microorganisms. In general, the CH/ST/SW and CH/ST/ SW/EOs composite films have greater mechanical, biological, physicochemical, and potential improvement of food shelf life applied as either coating or packaging material.
The alarming issue of food waste, coupled with the potential risks posed by petroleum-based plastic preservation materials to both the environment and human health necessitate innovative solutions. In this study, we prepared nanoemulsions (NEs) of chitosan (CS) and ginger essential oil (GEO) and systematically evaluated the effects of varying NEs concentrations (0, 10 %, 30 %, 50 %) on the physicochemical properties and biological activities of gelatin films. These films were subsequently applied to blueberry preservation. The scanning electron microscopy confirmed that the NEs were well-integrated with the Gel matrix, significantly enhancing the performance of the Gel films, including improvements of mechanical properties (tensile strength from 7.71 to 19.92 MPa; elongation at break from 38.55 to 113.65 %), thermal, and barrier properties (water vapor permeability from 1.52 x 10(-9)to 6.54 x 10(-10) g & sdot;m/Pa & sdot;s & sdot;m(2)). The films exhibited notable antibacterial and antioxidant activities due to the gradual release of GEO, thereby extending the storage life of blueberries. Moreover, the prepared composite films demonstrated excellent biodegradability and environmental friendliness, with the majority of the material decomposing within 30 days under soil microbial action. In conclusion, the active films loaded with NEs exhibit superior performance and hold significant potential for developing biodegradable materials for food preservation.
The aim of this work was to evaluate the influence of halloysite clay nanoparticles - unmodified (Hal) and organically modified (mHal) - and oregano essential oil (OEO), used as an antimicrobial agent in active packaging, on the biodegradation behavior of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) films. Five samples were prepared by melt mixing using 3 wt% clay, and 8 wt% and 10.4 wt% OEO. PHBV compositions containing OEO presented the highest rate of biodegradation, achieving 46% of mass loss after aging for 12 weeks in simulated soil. The addition of clay nanoparticles reduced the polymer's biodegradation to 32%. The compositions containing OEO showed a rough and layered surface with visible cracks, indicating degradation occurring through layer-by-layer erosion from the surface. This degradation was confirmed by the chemical changes on the surface of all samples, with a slight decrease in molar masses. The composition containing 8 wt% OEO presented an increase in the crystallization degree as a result of the preferential consumption of amorphous phase, whereas for the compositions containing clay nanoparticles, both crystalline and amorphous regions were degraded at similar rates. Therefore, the combination of additives allows the biodegradation process of PHBV to be controlled for use in the production of active packaging.
With a growing population of about 7.8 billion, humans are generating tons of waste in the form of non-biodegradable plastics on a daily basis that ends up in landfills and oceans. The introduction of packaging has been a blessing to mankind by facilitating the ease of convenience in transportation, delivery and general usage. The downside, however, is that majority of the packaging currently available is harmful to the environment and takes thousands of years to decay. This paper discusses the use of chitosan from shrimp shells and other marine animals' exoskeleton waste in food packaging industries. Chitosan extracted from marine organisms is modulated in the form of packaging material. Compared to conventional packaging, chitosan films are 73.4% biodegradable in soil under laboratory conditions whereas 100% degraded in an open field. Chitosan with metal oxides, essential oils, natural extracts, proteins and other polymers show enhanced tensile strength, water vapor permeability, oxygen and ultraviolet barrier. Chitosan and composite film show antimicrobial activity against gram positive and negative bacteria. Comparative approaches on environmental impacts between conventional plastics and chitosan films are enlightened, thereby highlighting the importance of natural polymers as packaging films that are considered economic based on the addition of additives.
Plant parasitic nematodes (PPNs) are acknowledged as a paramount factor which limits the production of staple crops and vegetables. Preferred standard control method had been the use of synthetic nematicides. However, owing to the undesirable consequences of the residual effect of nematicides in the environment, the need for alternative approaches becomes pertinent and this has prompted investigation into the nematicidal potential of extracts from Lawsonia inermis for practicable application on lettuce plants infected with Meloidogyne incognita in field experiments. The leaves of L. inermis were collected and divided into four parts for separate extraction and these were compared with the standard nematicide carbofuran individually. The essential oil (EO) was significantly more potent than the other extracts from L. inermis . There was no significant difference between plants treated with carbofuran and EO. The fractions were significantly better than crude methanol and ethanol extracts of L. inermis. Reproduction of M. incognita on lettuce plant roots was considerably reduced by utilization of L. inermis extracts. Notably higher vegetative growth was observed in treated lettuce plants. The IR, 1 H-NMR and 13 C-NMR spectral data analysis confirmed the presence of sesquiterpenes in the chromatographic fraction. The GC-MS profile indicated phytol as the major constituent of the EO. The results obtained from this study indicates that extracts from L. inermis could be a viable option in the management of M. incognita damaging lettuce in dependable vegetable production.
Several slug species are voracious pests of agricultural crops in northern Europe and are difficult to control. The parasitic nematode Phasmarhabditis hermaphrodita has been developed as a slug control product, but there is little information about whether it could be combined with other control methods (such as essential oils) to enhance its efficacy. Here, we carried out experiments in propagators with lettuce at three different time periods (July, September and October), and tested the following treatments: water (untreated control), cedarwood oil, P. hermaphrodita, cedarwood oil and P. hermaphrodita, and Tween 80 (used as an emulsifier for the cedarwood oil solution). Lettuce was grown in propagators with either 10 Deroceras reticulatum or 5 Arion vulgaris and the percentage of lettuce eaten over 14 days (as well as weight, the number of live slugs and eggs produced) was recorded. Cedarwood oil reduced slug damage, slug numbers and slug eggs in the experiments with D. reticulatum, and P. hermaphrodita performed well in two out of three experiments. The mixture of P. hermaphrodita and cedarwood oil was superior in reducing the proportion of lettuce eaten compared to single doses of each treatment in one out of three trials. In propagators with A. vulgaris all treatments performed poorly. In summary, P. hermaphrodita and/or cedarwood can be used to reduce damage by D. reticulatum, but are ineffective at controlling A. vulgaris. Slugs from the genus Arion continue to be a difficult group to control.