Chilli (Capsicum annuum L.) is an economically important seasonal spice crop, and its productivity and harvest quality are highly constrained by drought stress under many cultivation conditions. This study aimed to evaluate the effectiveness of nanocarbon-enriched fish hydrolysate in enhancing drought tolerance in chilli plants. The MI2 chilli variety was cultivated in pots using a Randomized Complete Block Design with seven treatments and six replicates per treatment. Treatments included a commercial Albert nutrient solution (positive control I), an inorganic solid fertilizer (positive control II), fish hydrolysate alone at 2.5% (v/v), and enriched with carbon nanoparticles at concentrations of 25, 50, and 75 mg/L, and water as a negative control. Following transplanting, four foliar spray applications were applied at five-day intervals. After the fertilization phase, drought stress was imposed by withholding irrigation for seven consecutive days. Growth parameters, including plant height, leaf area, root length, root volume, and root dry weight, and physiological parameters such as chlorophyll content and leaf relative water content were recorded. Although positive control I exhibited the highest plant height (16.42 cm) and leaf area (10.92 cm2), nanocarbon-enriched fish hydrolysate treatments at 50 mg/L and 75 mg/L displayed higher root length, root volume, root dry weight, chlorophyll content, and relative water content compared to both positive controls and fish hydrolysate alone, demonstrating that nanocarbon incorporation improves the efficacy of fish hydrolysate. Therefore, nanocarbon-enriched fish hydrolysate could be recommended as a cost-effective, environmentally friendly, and sustainable strategy under limited water availability in chilli cultivation.
This study investigated the potential of selected underutilized ornamental flowers for dried floral applications in Sri Lanka by comparing the effects of six drying techniques on their physical and ornamental quality. Five flower species, namely, Ixora coccinea, Plumeria rubra, Petrea volubilis, Bougainvillea spectabilis, and Holmskioldia sanguinea, were subjected to air drying, press drying, silica gel drying, sand-borax drying, hot air oven drying, and microwave oven drying. Significant differences (P < 0.05) were observed among the techniques for moisture loss, colour retention, texture, shape, brittleness, and overall quality. Results revealed that both drying methods and flower species significantly influenced the drying time and product quality. Microwave oven drying consistently achieved superior overall quality, less drying time, and better colour preservation in most species, while silica gel and hot air oven drying showed species-specific suitability. Among the flower species, B. spectabilis and H. sanguinea demonstrated the most favourable combination of physical and ornamental attributes after drying. These findings indicate that microwave oven drying and silica gel drying are the most effective and market-preferred methods for producing high-quality dried flowers in Sri Lanka, demonstrating strong potential to enhance the country’s value-added floral industry.
Centella asiatica (pennywort, “gotu kola”) and Basella alba L. (Ceylon green spinach) are locally available leafy greens rich in phytonutrients and phytochemicals. C. asiatica has been associated with memory enhancement, anti-carcinogenic effects, and therapeutic use in liver and kidney disorders, while B. alba is a valuable source of iron, vitamins, minerals, and antioxidants. Modern lifestyles limit green leaf consumption due to laborious preparation, prompting the development of a convenient herbal green sauce. A consumer survey involving 314 respondents informed formulation, followed by a sensory evaluation of sauces prepared with varying concentrations of leaf extracts (50-70% w/w). Based on sensory evaluation, the formulation containing 55% leaf extract with a 55:45 ratio of C. asiatica to B. alba showed the highest overall acceptability and was selected as the optimum formulation combined with water, corn flour, xanthan gum, sugar, salt, vinegar, spices, potassium sorbate, and a permitted artificial colourant to compensate for chlorophyll loss during processing. The herbal sauce contained 46.29 ± 1.07% moisture, 34.22 ± 0.12% ash, 1.30 ± 0.25% crude fat, 10.35 ± 0.76% crude protein, 33.57 ± 0.15% crude fibre, and 20.55 ± 0.27% carbohydrates. The physicochemical properties included pH 4.6, viscosity 1381.0 ± 1.2 mPa.s at 25°C, total soluble solids 12.08 ± 1.08, and strong green colour. Microbiological analysis confirmed absence of aerobic plate count, yeasts, moulds, coliforms, Escherichia coli, and Salmonella spp., ensuring product safety. Shelf life was six weeks at 25 ± 2°C based on microbial stability and physicochemical parameters. Functional properties of the herbal green sauce were evaluated, revealing total polyphenols of 0.52 mg GAE/g, flavonoids of 0.29 mg QE/g, and antioxidant activity higher than commercial tomato sauces. The sauce demonstrated enhanced nutritional and functional value over conventional condiments, and further studies are recommended to evaluate its therapeutic potential.
Plectranthus amboinicus, a member of the family Lamiaceae, is an herb that is commonly employed in traditional medicinal systems owing to its distinct therapeutic qualities. The demand for this rare herb is rising rapidly, suggesting that wild harvesting may be insufficient and could even result in the extinction of this precious herb. Thus, initiating commercial cultivation of the species is imperative to meet the growing demand for the herb while preserving its genetic foundation. The current study comprised three independent experiments that evaluated the most suitable cutting type, potting media, and irrigation schedule for in-vivo propagation of P. amboinicus under protected house conditions.Four distinct cutting types (tip/softwood cutting, single nodal semi-hardwood cuttings, double nodal semi-hardwood cuttings and triple nodal semi-hardwood cuttings), five different potting mixtures (topsoil: sand: compost-1:1:1, topsoil: sand: compost-1:2:1, topsoil: sand: compost-1:1:2, topsoil: compost-1:1 and topsoil: compost-1:2) and four different irrigation schedules (daily watering to field capacity, daily watering to 50% of field capacity, watering at one-day intervals to field capacity and watering at one-day intervals to 50% of field capacity ) were tested in Completely Randomized Design with 20 replicates per treatment. Data on plant height (cm), number of new buds and number of newly emerged leaves were collected at weekly intervals. Data on chlorophyll content (SPAD) and leaf area (mm2) were recorded six weeks after cutting establishment. Data were analyzed using analysis of variance (ANOVA), and treatment means were compared at the 5% level of significance. The results showed that softwood cuttings of P. amboinicus exhibited significantly higher growth and yield (P≤0.05), while the potting medium was composed of topsoil: sand: compost (1:2:1). The optimum irrigation schedule, out of the four examined, was daily watering to field capacity. In conclusion, softwood cuttings, topsoil: sand: compost (1:2:1) with daily watering to field capacity could be used as the most promising agronomic practice for the successful in-vivo propagation of P. amboinicus.
Postharvest losses of cashew (Anacardium occidentale L.) apple, an underutilized fruit in Sri Lanka, could be reduced by processing it into flour. This study evaluated three methods of cashew apple flour (CAF) preparation: oven drying of raw fruit (Method 1), boiled fruit (Method 2), and blanched fruit (Method 3), followed by grinding to fine powder. Flours were analyzed for their physicochemical and functional properties and proximate composition. Method 2 produced the most desirable flour characteristics, with high bulk density (0.67 g/mL), water absorption capacity (274.60%), and swelling power (8.95 g). Proximate composition of CAF from Method 2 included 2.24% ash, 4.54% crude fibre, 72.12% carbohydrate, 4.31% fat, and 9.08% crude protein. It was further tested in cookie formulations by blending with wheat flour (WF) at 0%, 10%, 20%, 30% and 40% substitution levels. Physical parameters were assessed, and products underwent sensory evaluation. Cookies with CAF-WF blends did not differ significantly (P>0.05) from the 100% WF control in weight, diameter, height, or spread ratio, though variations were observed in volume and density. The 30% CAF-70% WF blend yielded the best sensory attributes, including overall acceptability, appearance, colour, flavour, texture, and aroma. Compared to the control, this formulation contained lower protein (12.33%), fat (16.25%), and ash (1.57%), but significantly higher fibre (6.33%) levels. Overall, Method 2 produced CAF with favourable functional properties suitable for bakery applications. Incorporation of CAF at 30% substitution improved cookie fibre content without negatively affecting sensory quality. CAF thus has potential for value addition in food systems, though further research is needed on pasting properties, shelf life, and storability of CAF and CAF-based products.
