Screening of Escherichia coli O157:H7 contamination and nitrate content on Butterhead lettuce from market outlets

Escherichia coli O157:H7 is classified as biological hazard that can produce a bloody diarrhea due to its toxins. While nitrate in vegetables is classified as a chemical hazard if ingested greater than limit and risk getting gastrointestinal cancer and methemoglobinaemia. A study was conducted to obtain the information on E. coli O157:H7 contamination and nitrate content in Butterhead lettuce from local suppliers. The number of colonies E. coli O157:H7 from the lettuce was enumerated using standard plate count and the nitrate content was measured using nitrate meter. From the experiment, it was found that E. coli O157:H7 contamination of Butterhead lettuce in Malaysia is still within the safe limit for the consumers while the nitrate content was distributed differently between leaf structures; midrib, outer adult leaf blade and young leaves. Lettuce midrib and outer adult leaf blade had a higher concentration of nitrate compared to the young leaves

Combining chitosan and vanillin to retain postharvest quality of tomato fruit during ambient temperature storage

Tomato, being a climacteric crop, has a relatively short postharvest life due to several factors such as postharvest diseases, accelerated ripening, and senescence that trigger losses in quantity and quality. Chemicals are widely used to control postharvest disease. Inaptly, it leads to detrimental effects on human health, environment and it is leads to increased disease resistance. Chitosan and vanillin could be an alternative to disease control, maintain fruit quality, and prolong shelf life. The aim of this research was to evaluate the potential of chitosan and vanillin coating on the tomato fruit’s physicochemical quality during storage at 26 ± 2 °C/60 ± 5% relative humidity. Chitosan and vanillin in aqueous solutions i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin, and 1.5% chitosan + 15 mM vanillin, respectively, were used as edible coating. The analysis was evaluated at 5-day intervals. The results revealed that 1.5% chitosan + 15 mM vanillin significantly reduced disease incidence and disease severity by 74.16% and 79%, respectively, as well delaying weight loss up to 90% and reducing changes in firmness, soluble solids concentration, and color score. These coatings also reduced the rate of respiration and the rate of ethylene production in comparison to the control and fruit treated with 0.5% chitosan + 10 mM vanillin. Furthermore, ascorbic acid content and the antioxidant properties of tomato were retained while shelf life was prolonged to 25 days without any negative effects on fruit postharvest quality

Development of Vernonia amygdalina leaf extract emulsion formulations in controlling gray mold disease on tomato (Lycopersicon esculentum Mill.)

Postharvest fruits including tomatoes are commonly infected by gray mold disease resulting in significant economic losses in the fruit industry. Therefore, this study aimed to develop botanical fungicide derived from Vernonia amygdalina leaf extract to control gray mold on tomato. The emulsion formulation containing surfactant, oil carrier and water was optimized at different non-ionic alkyl polyglucoside surfactants through eleven combinations of oil to surfactant ratio (0:10, 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1 and 10:0 w/w). From eight selected formulations, two formulations, F5 and F7 showed stable in storage, remarkable thermodynamic stability, smaller particle size (66.44 and 139.63 nm), highly stable in zeta potential (−32.70 and −31.70 mV), low in polydispersity index (0.41 and 0.40 PdI), low in viscosity (4.20 and 4.37 cP) and low in surface tension (27.62 and 26.41 mN/m) as compared to other formulations. In situ antifungal activity on tomato fruits showed F5 formulation had a fungicidal activity against B. cinerea with zero disease incidence and severity, whereas F7 formulation reduced 62.5% disease incidence compared to a positive control with scale 1. Based on these findings, F5 formulation exhibited pronounced antifungal activity and may contribute to the development of new and safe antifungal product against gray mold on tomato

Development of Edu-Fertiblox digital game using roblox as a teaching aid for the fertigation system topic in the design and technology subject form 1

A lack of practical facilities frequently causes problems for teachers and students. The Edu-Fertiblox digital game has been developed for the purpose of being a teaching aid (TA) for the topic of Fertigation Systems in Design Technology Subject Form 1. This study aimed to identify the needs of TAs for the topic of fertigation systems, develop the Edu-Fertiblox digital game as a TA, and assess the usability of the digital game. The development of this game is using the ADDIE model as a research design. The digital game was developed using Roblox Studio. After that, Edu-Fertiblox was evaluated for its usability by three informants, consisting of teaching staff who are experts in Design and Technology. The findings showed all the informants agreed that the Edu-Fertiblox digital game can be used as a teaching aid for the Fertigation System topic of Design and Technology Form 1

Selecting antagonistic yeast for postharvest biocontrol of Colletotrichum gloeosporioides in papaya fruit and possible mechanisms involved

Colletotrichum gloeosporioides causes anthracnose disease in papaya fruit resulting in tremendous economic loss due to its latent infection. This study aimed to evaluate the biocontrol activity of antagonistic yeasts against C. gloeosporioides in papaya and determine the possible mechanism involved. One hundred and ten yeast strains were isolated from different parts of the papaya plant. Among them, only five strains, namely F001, F006, L003, FL013 and LP010, showed more than 55% radial growth inhibition of C. gloeosporioides. These five potent yeast strains were further evaluated in vitro and in vivo. The results indicated that strain F001 had the strongest biocontrol activity based on spore germination and fungal growth inhibition. In Vivo, the strain F001 caused 66.7% and 25% reductions in disease incidence and severity, respectively. Based on molecular identification, the strain F001 was confirmed as Trichosporon asahii. Despite there was no significant induction of defense enzyme activities found on the treated fruits, SEM observation showed direct attachment of T. asahii with the fungal hyphae and interfere in their establishment to the fruit surface. Based on these findings, the antagonistic yeast T. asahii strain F001 may be used as a potential natural biological control agent against anthracnose disease in papaya frui

A systematic review of emerging trends in crop cultivation using soilless techniques for sustainable agriculture and food security in post-pandemic

By 2050, the global population is anticipated to reach 10 billion, marking a significant 34% increase and raising concerns regarding food availability. Challenges such as the recent pandemic, which led to workforce and input shortages in agriculture, have made it difficult for many countries to maintain adequate food self-sufficiency (SSL). It is crucial to explore various farming methods to ensure that food remains available and affordable, especially in urban areas where over 55% of the population resides. Traditional agriculture faces issues like poor soil and excessive fertilizer use, which harm the environment. These factors threaten sustainable agriculture and food security, particularly in urban environments. Adopting sustainable soilless technology can enhance urban agriculture by providing a controlled environment for producing healthy food and addressing these challenges post-pandemic. This review, utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, a widely recognized and rigorous method for conducting systematic reviews, focused on urban agriculture, specifically soilless technologies, as emerging trends in crop cultivation. It examined conventional and cutting-edge urban production systems aimed at promoting sustainable agriculture and food security. The review examined soilless farming techniques such as aeroponics, hydroponics, and aquaponics, highlighting their environmental impact, resource efficiency, and water usage. It carefully considered the advantages and disadvantages of these technologies compared to conventional soil-based farming. Furthermore, the review showcased the successful cultivation of various fresh vegetables and fruits using soilless technologies, each with advantages supporting urban agriculture and overall food security. The findings suggest that these innovative strategies hold promise in fostering sustainable urban agriculture and ensuring food security during a pandemic. These results lay the groundwork for establishing a framework to assess the sustainability of urban agricultural strategies and their practical application in real-world scenarios

Anatomy education environment measurement inventory (AEEMI): a cross-validation study in Malaysian medical schools

Background: The Anatomy Education Environment Measurement Inventory (AEEMI) evaluates the perception of medical students of educational climates with regard to teaching and learning anatomy. The study aimed to cross-validate the AEEMI, which was previously studied in a public medical school, and proposed a valid universal model of AEEMI across public and private medical schools in Malaysia. Methods: The initial 11-factor and 132-item AEEMI was distributed to 1930 pre-clinical and clinical year medical students from 11 medical schools in Malaysia. The study examined the construct validity of the AEEMI using exploratory and confirmatory factor analyses. Results: The best-fit model of AEEMI was achieved using 5 factors and 26 items (χ 2 = 3300.71 (df = 1680), P < 0.001, χ 2/df = 1.965, Root Mean Square of Error Approximation (RMSEA) = 0.018, Goodness-of-fit Index (GFI) = 0.929, Comparative Fit Index (CFI) = 0.962, Normed Fit Index (NFI) = 0.927, Tucker–Lewis Index (TLI) = 0.956) with Cronbach’s alpha values ranging from 0.621 to 0.927. Findings of the cross-validation across institutions and phases of medical training indicated that the AEEMI measures nearly the same constructs as the previously validated version with several modifications to the item placement within each factor. Conclusions: These results confirmed that variability exists within factors of the anatomy education environment among institutions. Hence, with modifications to the internal structure, the proposed model of the AEEMI can be considered universally applicable in the Malaysian context and thus can be used as one of the tools for auditing and benchmarking the anatomy curriculum

Chitosan and Other Edible Coatings with Antimicrobial Activity: Synthesis, Properties and Horticultural Applications

Antimicrobial edible coatings for whole or fresh-cut fruits and vegetables based on natural biopolymers that serve as carriers of antimicrobial agents or that are inherently antimicrobial, such as chitosan, are increasingly gaining interest from researchers and industry due to their potential to maintain quality and safety. Additionally, edible coatings can also function as a barrier to water vapors and gases, regulating physiological aspects in fruit. Despite the substantial research progress in antimicrobial edible coatings for fresh and fresh-cut fruits and vegetables, the development of tailor-made solutions according to specific commercialization needs still represents a technological challenge due to important physical, physiological, and biochemical differences among the wide variety of fresh horticultural commodities. The development of edible films and coatings with antimicrobial activity requires knowledge of the chemical bases to develop optimized edible coating formulations, the effects of the coatings on different postharvest pathogens in in vitro studies and in different fruit matrices, as well as their effect on fruit quality during postharvest storage

Nanoemulsion formulation of Vernonia amygdalina delile against Botrytis cinerea causing gray mold disease in tomato and their effects on postharvest quality

Gray mold disease caused by Botrytis cinerea is one of the significant postharvest losses mostly observed during tomato storage and transportation. Synthetic fungicide is currently used to control this disease, but it poses adverse effects to human health, environment, and development of resistance to synthetic fungicides. V. amygdalina extract showed antifungal activity which could be a sustainable tool as biofungicide for plant disease management. The present study aimed to screen phytochemical compounds in V. amygdalina leaf extract, develop nanoemulsion formulations containing V. amygdalina crude extract, evaluate antifungal activities of nanoemulsions against B. cinerea and preserve postharvest quality. Ten fungal isolates were obtained from symptomatic tomato fruits sampled from Cameron Highlands, Pahang, Malaysia. Fungal colonies on PDA appeared cottony and white to gray color. Conidia were ovoid in shape, hyaline, and measured 10.03-16.08 × 7.37-11.15 μm. To confirm molecular identification, the primer pair ITS4/ITS5 of rDNA was used for amplification and sequencing of isolates. The sequences with GenBank accession MT012053-MT012062 were the closest match to Botrytis cinerea with query coverage was 98-99%. Based on pathogenicity assay, the isolates indicated highly pathogenic with the maximum disease severity was 90% (Isolate MT012058). In vitro test showed leaf extracts of aqueous, hexane, dichloromethane (DCM) and methanol at 100-500 mg/mL were significantly inhibited mycelial growth of B. cinerea. DCM was the most effective, which inhibited up to 75.74% of the mycelial growth of B. cinerea. The top major chemical compounds identified in DCM extract using GC-MS analysis were squalene, phytol, triacontane, heptacosane, and neophytadiene. For in vivo bioassay, the fruits treated with dichloromethane extract at 400 and 500 mg/mL showed the lowest disease incidence with mild severity of infection. The SEM observation proved that the treatment altered the fungal morphology, which leads to fungal growth inhibition. The nanoemulsion system containing oil, water and surfactant was obtained using spontaneous emulsification technique by employing four surfactants. From eight selected formulations, two formulations, F5 and F7 showed stability in storage, remarkable thermodynamic stability, small-sized droplet (66.44 and 139.63 nm), highly stable in zeta potential (−32.70 and −31.70 mV), low in polydispersity index (0.41 and 0.40 PdI), low in viscosity (4.20 and 4.37 cP) and low in surface tension (27.62 and 26.41 mN/m) compared to other formulations. In vivo efficacy on tomato fruits showed F5 formulation had a fungicidal activity against B. cinerea with zero disease incidence and severity, whereas F7 formulation reduced 62.5% disease incidence compared to a positive control with scale 1. F5 and F7 nanoemulsions exhibited higher enzyme activities of PAL, POD, and SOD compared to benomyl and control fruits. Meanwhile, F5 nanoemulsion triggered significantly higher PPO and CAT activities compared to F7 nanoemulsion. F5 nanoemulsion showed delays in fruit maturity, minimal weight loss, slower changes in firmness, TA, SSC and pH, retained the vitamin C content, fair in phenolic content and execute high antioxidant activities. In conclusion, F5 nanoemulsion has a fungicidal effect on B. cinerea, induces higher defense-enzymes activities, and gives optimum postharvest quality in tomato. Thus, F5 nanoemulsion containing V. amygdalina leaf extract could be useful for inhibiting gray mold disease on tomato fruit and has the potential as a natural antifungal agent

Effects of production systems and ozone treatment on nitrate content and E. coli O157:H7 contaminations of Butterhead lettuce

Butterhead lettuce, a salad crop pose to food safety risk issues because it is normally consume raw. The information regarding nitrate and Escherichia coli O157:H7 contaminations status on Butterhead lettuce in Malaysia is still scanty. Not much work of this nature is carried out locally. Recently, an outbreak of E. coli was happened in Germany, which one of the most stringent countries in term of food safety on fresh produce. Hence, this study seemed inevitable to be carried out. The first experiment, a market study, to determine the level of nitrate and E. coli O157:H7 contaminations of Butterhead lettuce. The result showed that nitrate levels exceeded the maximum limit but the bacteria contaminations were still under safe limit. The second experiment was to determine the effect of harvesting stage on the nitrate content, quality and nitrate reductase activity (NRA) of Butterhead lettuce, grown by hydroponic and organic systems. After 35, 38, 41 and 44 days of transplanting (DAT),the lettuce harvested and the studied effects were determined. Nitrate content in hydroponic lettuce was higher compared to organic lettuce. The accumulation varies with leaf parts, the highest being in midribs, followed by outer adult leaf blades and young leaves. For hydroponic lettuce, extended harvesting stage was found to reduce nitrate content. Fourty one DAT was the optimum stage to harvest with significantly higher reduction of nitrate content. At this stage, the fresh weight, firmness and color were still acceptable. However, harvesting stage had no effect on nitrate content in organic lettuce. NRA was found to be higher in young leaves compared with outer adult leaf blades and midribs. The third experiment was to determine effect of different aqueous ozone concentrations on E. coli O157:H7, nitrate and nitrite contents, and postharvest quality of Butterhead lettuce. The lettuce was treated with aqueous ozone at concentrations of 0, 3 and 5 mg.Lˉ¹ and stored at 10 °C for 12 days. The quality was assessed on day 0, 4, 8 and 12 of storage by comparing the changes. The number of E. coli in organic lettuce was found to be higher than hydroponic lettuce. The aqueous ozone at 5 mg.Lˉ¹ treatments was effective in reducing E. coli colonies but with quality compromised and the effectiveness decreased as the storage period progressed. Ozone at 3 mg.Lˉ¹ was a potential concentration on reducing E. coli without giving in to quality. In conclusion, the consumers and producers should apply hygienic practices to ensure safe consumption. The optimum harvest stage of Butterhead lettuce is at 41 DAT. A potential concentration of aqueous ozone was 3 mg.L-1 on reducing E. coli O157:H7 contamination without detrimental effects on lettuce quality. Lettuce can be stored in cool storage for up to eight days