The study investigated the anti-inflammatory activity of the hydro methanolic extract of six leafy vegetables, namely Cassia auriculata, Passiflora edulis, Sesbania grandiflora, Olax zeylanica, Gymnema lactiferum, and Centella asiatica. The anti-inflammatory activity of methanolic extracts of leafy vegetables was evaluated using four in vitro-based assays: hemolysis inhibition, proteinase inhibition, protein denaturation inhibition, and lipoxygenase inhibition. Results showed that the percent inhibition of hemolysis from these leaf extracts (25–100 µg/mL dry weight basis (DW)) was within the range from 5.4% to 14.9%, and the leaves of P. edulis and O. zeylanica showed a significantly higher (p < 0.05) inhibition levels. Percent inhibition of protein denaturation of these leafy types was within the range of 36.0–61.0%, and the leaf extract of C. auriculata has exhibited a significantly higher (p < 0.05) inhibition level. Proteinase inhibitory activity of these leaf extracts was within the range of 20.2–25.9%. The lipoxygenase inhibition was within the range of 3.7–36.0%, and the leaf extract of G. lactiferum showed an improved ability to inhibit lipoxygenase activity. In conclusion, results revealed that all the studied leaves possess anti-inflammatory properties at different levels, and this could be due to the differences in the composition and concentration of bioactive compounds.

This study aimed to evaluate the effect of cooking (boiling, steaming, and frying) on polyphenols, flavonoids, carotenoids and antioxidant activity of six edible leaves. The total antioxidant capacity of the fresh and cooked leaves was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and singlet oxygen scavenging assays. The results revealed that frying caused a reduction in major bioactives and antioxidant activities in all leafy vegetables tested. However, steamed and boiled leaves of C. auriculata and C. asiatica have shown greater levels of polyphenols, flavonoids, and antioxidant capacity compared with fresh leaves. Polyphenol and flavonoid contents of boiled S. grandiflora and G. lactiferum were higher than that of their fresh form. Boiled and steamed O. zeylanica and S. grandiflora have shown higher carotenoids. Boiled and steamed leaves of P. edulis have shown higher antioxidant activity. The impact of cooking on the changes in bioactive concentrations and antioxidant capacities are dependent on the species and the method of cooking.

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Green leafy vegetables available in Sri Lanka have not been fully exploited though they are stipulated to be rich sources of natural antioxidant. This study examined the antioxidant properties of thirty four edible green leafy vegetables popular in Sri Lanka. Methanolic extracts of leafy vegetables were analyzed for total phenolic, carotene and chlorophyll content and were evaluated for total antioxidant capacity, reducing power, lipid peroxidation and DPPH radical scavenging assays. The results indicated that these leafy vegetables have remarkable variations in their antioxidant activities. Among the plant materials screened for their antioxidant properties, Sesbania grandiflora, Cassia auriculata, Murraya koenigii Spreng, Passiflora edulis, Gymnema lactiferum and Olax zeylanica, showed high carotene content, antioxidant activities and polyphenolics compared to other leaf varieties tested. A good correlation was observed between antioxidant assays and polyphenolics of the leafy vegetables.

The aim of the present study was to evaluate the effect of cooking (boiling, steaming, and frying) on anti-inflammation associated properties in vitro of six popularly consumed green leafy vegetables in Sri Lanka, namely: Centella asiatica, Cassia auriculata, Gymnema lactiferum, Olax zeylanica, Sesbania grnadiflora, and Passiflora edulis. The anti-inflammation associated properties of methanolic extracts of cooked leaves were evaluated using four in vitro biological assays, namely, hemolysis inhibition, proteinase inhibition, protein denaturation inhibition, and lipoxygenase inhibition. Results revealed that the frying of all the tested leafy vegetables had reduced the inhibition abilities of protein denaturation, hemolysis, proteinase, and lipoxygenase activities when compared with other food preparation methods. Steaming significantly increased the protein denaturation and hemolysis inhibition in O. zeylanica and P. edulis. Steaming of leaves increased inhibition activity of protein denaturation in G. lactiferum (by 44.8%) and P. edulis (by 44%); hemolysis in C. asiatica, C. auriculata, and S. grandiflora; lipoxygenase inhibition ability in P. edulis (by 50%), C. asiatica (by 400%), and C. auriculata leaves (by 250%); proteinase inhibition in C. auriculata (100%) when compared with that of raw leaves. In general, steaming and boiling in contrast to frying protect the health-promoting properties of the leafy vegetables.

Blends of all‐purpose wheat flour and coconut flour (ground residue of virgin coconut oil extraction) were prepared for the preparation of noodles. Mixing behavior (water absorption, arrival, dough development time and stability) of the blends was determined by farinograph. Noodles were evaluated for cooked weight, cooking losses, nutritional composition and sensory properties. Water absorption decreases with the substitution increases, whereas dough development time, arrival time and stability were increased up to 20% substitution level. However, at 30% level, an unstable farinogram was observed. Weight increase during cooking is not significantly different to that of noodles prepared with control (100% wheat flour) in all levels of substitutions tested, and solid losses remained less than 5% during cooking in all blends. Protein and fiber content of noodles increased when substitution level increased. Coconut flour addition up to 20% was not significantly different to noodles made with 100% wheat flour for all sensory properties, whereas 30% substitution affects negatively for appearance, texture and overall acceptability of the product. PRACTICAL APPLICATIONS Wheat flour is not a good source of fiber and protein, although wheat flour noodles are popular in the world. Coconut flour is considered as a good source of fiber (10.45%) and protein (21.65%). It has been estimated that the amount of wheat flour used for noodles making in Asia accounts for about 40% of the total flour consumed, so coconut flour can be incorporated up to 20% into wheat flour noodles in order to improve its health benefits.

The antioxidant potency of soluble and bound phenolic extracts of freeze‐dried six leafy vegetables was investigated using in vitro systems; singlet oxygen scavenging, hydroxyl radical scavenging, nitric oxide radical scavenging, and ABTS radicals assays. Further rutin, lutein, and β‐carotene content of leaves were analysed. The results revealed that both soluble and bound phenolic extracts have exhibited antioxidant potential toward free radicals and reactive oxygen species concerned. However, soluble extracts showed a higher content of phenolics and flavonoids than the bound counterpart. The highest rutin, lutein, and β‐carotene contents were observed in the leaves of Cassia auriculata, and the leaves of Passiflora edulis showed the highest vitamin C content. Positive associations between phenolics and antioxidant activities except for singlet oxygen radical scavenging ability were observed. Among the leafy types studied, C. auriculata have shown to possess more antioxidant bioactives such as β‐carotene, lutein, and rutin and antioxidant activities. Practical applications This paper will give information about major bioactive compounds such as β‐carotenoids, rutin, and lutein and antioxidant activity in selected green leafy vegetables due to cooking treatments. This is important for the public those concern about the healthy diet in the view of selecting leafy vegetables to combat many oxidative stress‐related chronic diseases.

Response surface methodology has been used to optimize the extraction conditions for total phenolics and carotenoids from leaves of Centella asiatica. Solvent concentration (30%–100%), extraction temperature (30–60°C), and extraction time (30–90 min) were used as the independent variables. A second‐order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolics (R2 = 84.75%, p < 0.004) and carotenoid (R2 = 78.74, p < 0.019) contents. The optimum extraction conditions of ethanol concentration, extraction temperature, and extraction time for phenolics were 6.1%, 70.2°C, and 110.5 min and for carotenoids, the optimum parameters were 100%, 70.2°C, and 110.5 min, respectively. The optimal predicted contents for total phenolics (9.03 mg Gallic Acid Equivalent (GAE)/g DW) and carotenoid (8.74 mg/g DW) values in the extracts were agreed with the experimental values obtained with optimum extraction conditions for each response, and also they possess significantly higher total antioxidant capacity.