Technique for order preference by similarity to ideal solution (TOPSIS): a MCDM approach for selecting suitable solvent considering biochemical profiles and in vitro antibacterial efficacy of petioles of betel leaf (Piper betle L.).

Petioles of betel leaf (BLP) are the major industrial by-products of betel leaf industries sold at throwaway prices or used as cattle feed. The present work was taken up to evaluate suitable solvent based on yield, antioxidant, and antimicrobial properties to isolate extract of BLP using the Shannon entropy-TOPSIS method. Four solvents were chosen for the extraction process: hexane, toluene + ethanol (2:1), acetone, and ethanol. The findings showed that ethanol-based BLP extract had the highest TPC value, measuring 2193.71 ± 0.17 mg of gallic acid equivalence/g of dry extract, while acetone-based extracts had the highest TFC value, measuring 8.03 mg of quercetin equivalent/g of dry extract. Radical scavenging activities like DPPH (IC50 = 52.44 µg/mL), ABTS (IC50 = 62.41 µg/mL), and FRAP (8.03 mg QE/g of dry extract) were found best for acetone extract. The antibacterial study of the extracts revealed that acetone extract was more sensitive to Gram-positive and Gram-negative bacterial strains followed by ethanol, toluene + ethanol, and hexane extracts. Among five foodborne bacteria, B. subtilis showed the highest susceptibility against all extracts. GC-MS analysis showed that acetoxychavicol acetate (31.27%) (PubChem ID: 119,104), germacrene D (7.24%) (PubChem Id: 531,750), isoxylic acid (22.56%) (PubChem ID: 11,892), and cis-1,2-indandiol (43.92%) (PubChem ID: 20,758) are four major compounds among 22 components. TOPSIS analysis revealed that acetone extract had the highest relative closeness value (0.71) followed by ethanol (0.65), toluene + ethanol (0.53), and hexane (0.32). These results indicate that acetone extract of BLP can be considered an alternative to synthetic active ingredients in the future. These results indicated that TOPSIS method has computational robustness for selecting a solvent comparing yield, antioxidant, and antimicrobial activities of extract of a plant part.

Modelling the effect of guar gum on physical, optical, barrier and mechanical properties of potato starch based composite film.

The composition of potato starch (PS) and guar gum (GG) based biodegradable composite film was optimised based on physical, optical, mechanical and barrier properties. The rotatable central composite design applying desirability function was used to assess the effect of PS (2.5-4.5%), GG (0.2-0.8%) and glycerol (15-35%). The optimisation was performed considering minimization of film solubility, opacity, yellowness index and water vapour permeability; and maximization tensile strength and percentage elongation at break. Viscosity of film forming solution; thickness, moisture content and whiteness index of the films were also evaluated. The optimum value of PS, GG and glycerol was 3.7%, 0.4% and 15% (of total solids), respectively. All the independent variables depicted significant effect on the responses (p < 0.05) except starch which did not exhibit any statistically significant effect on WVP. The structural characterisation of the optimised film was also analysed by FESEM and XRD which point to the semi-crystalline nature of the developed film.