Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. However, it is very susceptible to the infection initiated by Fusariumoxysporum fruit rot, which shortens post-harvest life and thus reduces market value. This disease can be regulated appropriately by the application of synthetic fungicides. However, chemical fungicides constitute a serious health risk, and have harmful environment effects and increase disease resistance, even when microbes are dead. Hence, to overcome this problem, chitosan and vanillin, which have antimicrobial bioactive properties against the growth of microorganisms, could be an alternative to disease control, while maintaining fruit quality and prolonging shelf life. The aim of this research was to evaluate the antimicrobial activity of chitosan and vanillin towards the inoculate pathogen and to investigate the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot and defense-related enzymes (PAL, PPO and POD). 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, were used as edible coatings on tomatoes stored at 26 ± 2 °C and 60 ± 5 relative humidity. The result revealed 1.5% chitosan + 15 mM vanillin was able to control disease incidence by 70.84% and severity by 70%. These combinations of coatings were also able to retain phenylalanine ammonia-lyase (PAL), peroxidase activity (POD), and polyphenol oxidase (PPO) enzyme activities as well as prolong shelf life of tomatoes up to 15 days.

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Clinacanthus nutans, commonly known as Sabah snake grass, is one of the more important medicinal plants in Malaysia’s herbal industry. C. nutans has gained the attention of medical practitioners due to its wide range of bioactive compounds responsible for various biological activities, such as anti-cancer, anti-venom and anti-viral activities. Due to its high pharmacological properties, the species has been overexploited to meet the demands of the pharmaceutical industry. The present study was conducted to establish a suitable in vitro culture procedure for the mass propagation of C. nutans. Murashige and Skoog (MS) basal medium, supplemented with different types of cytokinins, auxins, basal medium strength and sucrose concentrations, were tested. Based on the results, a full-strength MS basal medium supplemented with 12 µM 6-benzylaminopurine (BAP) and 30 g/L sucrose was recorded as the best outcome for all the parameters measured including the regeneration percentage, number of shoots, length of shoots, number of leaves and fresh weight of leaves. In the analysis of the phenolics content and antioxidant activities, tissue-cultured leaf extracts assayed at 100 °C exhibited the highest phenolic content and antioxidant activities. The propagation of C. nutans via a plant tissue culture technique was recorded to be able to produce high phenolic contents as well as exhibit high antioxidant activities.

This study aimed to evaluate the significant extraction factors in achieving higher recovery yield of total polyphenols, phenolic acids and flavonoids content from Citrus limon peel using two-level factorial design. The effect of five independent factors including drying temperature (40–60 °C), methanol concentration (20–60%), extraction temperature (28–60 °C), extraction time (30–60 min) and storage duration (0–14 days) were evaluated. Among all the examined factors, results showed that drying temperature, storage duration and extraction temperature were the most significant and contributing factors affecting the total polyphenols, phenolic acids and flavonoids content of lemon peel at P < 0.05. On the contrary, methanol concentration and extraction time exhibited the least significant and contribution at P greater than 0.05. In conclusion, the experimental domain factors were successfully obtained from this experiment, Therefore, further study on optimization of the obtained factors will be conducted in the future study using response surface methodology.

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.