Twenty-five strains of plant-growth-promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase and 10 strains of rhizobia were isolated from rhizosphere soil samples and nodules of mung bean. They were screened in separate trials under salt-stressed axenic conditions. The three most effective strains of PGPR (Mk1, Pseudomonas syringae ; Mk20, Pseudomonas fluorescens ; and Mk25, Pseudomonas fluorescens biotype G) and Rhizobium phaseoli strains M1, M6, and M9 were evaluated in coinoculation for their growth-promoting activity at three salinity levels (original, 4 dS·m(-1), and 6 dS·m(-1)) under axenic conditions. The results showed that salinity stress significantly reduced plant growth but inoculation with PGPR containing ACC deaminase and rhizobia enhanced plant growth, thus reducing the inhibitory effect of salinity. However, their combined application was more effective under saline conditions, and the combination Mk20 × M6 was the most efficient for improving seedling growth and nodulation. The effect of high ethylene concentrations on plant growth and the performance of these strains for reducing the negative impact of saline stress was also evaluated by conducting a classical triple-response bioassay. The intensity of the classical triple response decreased owing to inoculation with these strains, with the root and shoot lengths of inoculated mung bean seedlings increasing and stem diameter decreasing, which is a typical response to the dilution in a classical triple response bioassay. Thus, coinoculation with PGPR containing ACC deaminase and Rhizobium spp. could be a useful approach for inducing salt tolerance and thus improving growth and nodulation in mung bean under salt-affected conditions.

This study was carried out to compare the antioxidant and nutritional properties of coconut (Cocos nucifera L.) sap with other natural sources of sugar such as sugar palm (Borassus flabellifer) and sugarcane (Saccharum officinarum L.). Coconut sap and juice from sugar palm and sugarcane were analyzed for proximate composition, pH and total soluble solid (TSS), color, sugar profile, vitamin profile, antioxidant properties (total phenolic contents, DPPH, FRAP, and ABTS), and mineral content. The results indicated that coconut sap possesses high DPPH (23.42%), FRAP (2.09 mM/ml), and ABTS (21.85%) compared with the juices. Coconut sap also had high vitamin C (116.19 µg/ml) and ash (0.27%) contents, especially in potassium (960.87 mg/L) and sodium (183.21 mg/L) which also indicating high content of minerals. These properties showed that coconut sap could be served as a potential healthier sugar source compared with sugar palm and sugarcane juices.

Enzyme assisted solvent extraction (EASE) of phenolic compounds from watermelon (C. lanatus) rind (WMR) was optimized using Response Surface Methodology (RSM) with Rotatable Central Composite Design (RCCD). Four variables each at five levels i.e. enzyme concentration (EC) 0.5-6.5 %, pH 6-9, temperature (T) 25-75 °C and treatment time (t) 30-90 min, were augmented to get optimal yield of polyphenols with maximum retained antioxidant potential. The polyphenol extracts obtained under optimum conditions were evaluated for their in-vitro antioxidant activities and characterized for individual phenolic profile by RP-HPLC-DAD. The results obtained indicated that optimized EASE enhanced the liberation of antioxidant phenolics up to 3 folds on fresh weight basis (FW) as compared to conventional solvent extraction (CSE), with substantial level of total phenolics (173.70 mg GAE/g FW), TEAC 279.96 mg TE/g FW and DPPH radical scavenging ability (IC50) 112.27 mg/mL. Chlorogenic acid (115.60-1611.04), Vanillic acid (26.13-2317.01) and Sinapic acid (113.01-241.12 μg/g) were major phenolic acid found in EASEx of WMR. Overall, it was concluded that EASE might be efficient and green technique to revalorize under-utilized WMR into potent antioxidant phenolic for their further application in food and nutraceutical industries.

In the current study, antioxidant potential of licorice extracts was determined through different assays. For optimum recovery of bioactive components, three solvents (ethanol, methanol, and ethyl acetate) were employed at different ratios with water (25:75, 50:50, and 75:25) and supercritical fluid extracts (SFE) were obtained at varying pressures (3,500, 4,500, and 5,500 psi).Results exhibited that the extraction of antioxidant compounds from licorice increased with increasing solvent concentration. Among solvent extracts, 75% ethanolic extract showed highest total phenolic content (TPC), total flavonoids content (TF), and antioxidant activity. The supercritical CO 2 extract obtained at 5,500 psi pressure exhibited highest values for TPC, TF, and antioxidant capacity. It was evident from HPLC analysis that the highest recovery of major bioactive components (glycyrrhizin and glabridin) was obtained through supercritical CO 2 extraction at elevated pressures. Practical applicationsLicorice is a rich source of biologically active components with history of medicinal use. The current study provides an approach to maximize the recovery of desired components from licorice that can be used in different formulations with antioxidant potential. K E Y W O R D S antioxidant activity, licorice, phytochemical content, solvent extraction, supercritical CO 2 extraction