Optimization of recipe for development of Aonla squash- A Response surface methodology approach

Central Composite Design (CCD) was employed for optimizing the recipe for development of Aonla squash with juice content (25 to 40%), acidity (1.00 to 1.10%) as independent variables and adjusting 50% total soluble solids. Thirteen different experimental combinations given by RSM design were used to investigate the effect of independent process variables on four product responses developed squash. RSM evaluated responses of the 13 squash recipes by second order quadratic equations and found that pH ranged from 2.69-3.00, ascorbic acid from 102-212 mg/100ml, browning from 0.428- 0.579 and overall acceptability scores from 6.25-7.75. ANOVA analysis showed that the product responses of beverages were significantly affected (at 5%) by changes in juice and acidity of the squash recipes. Overall acceptability scores of the beverage increased with the increase in proportion of juice content from 25 to 40%. The coefficient of determination i.e., R2 for all responses was higher than 0.95 and nonsignificant lack of fit was observed for all models; which was desirable. Through numerical optimization, standardized recipe selected by RSM for aonla squash was with 40% juice and 1% acidity getting highest desirability of 0.991. The pH, ascorbic acid, browning and overall acceptability for the optimum recipe predicted by the design were 2.96, 197.8 mg/100 ml, 0.557 and 7.7, respectively. Thus, present study was first in its kind to optimize aonla squash recipe by using RSM as a tool which gave advantage of not only selecting best recipe but also provided impression of the influence of ingredients used in squash’s preparation on its physico-chemical profile

Development of promiscous rhizobia for diverse rabi legumes (Chickpea, Pea and Lentil)

Conjugation between microsymbiont was used to create genetic variations in rhizobia for diverse rabi legumes (chickpea, pea and lentil) with better characteristics in nodulation and nitrogen fixation process. Ten antibiotics were used as selectable markers for the screening of twenty four bacterial strains to be used in mating experiments for obtaining transconjugants. All bacterial strains were sensitive to gentamycin and resistant to streptomycin, kanamycin and sulphanilamide. Total five fusants were obtained from each rhizobial cross combination with the help of electro-poration. Modified transconjugants, rhizobial strains had promiscuous infection with 50-122% more nodules showed significant increase in shoot fresh weight, dry weight and total nitrogen content in chickpea, pea and lentil plants. Electrofusantsrhizobial strains improved shoot nitrogen content up to 67% in lentil and 54% in pea and chickpea plants. The amount of nitrogen fixed in chickpea was highest (3.71gm) by transconjugants DP-C6- HLN followed by DP-C6-HP14 (3.56gm). Transconjugants DP-HP14-HLN fixed the highest amount of nitrogen (3.92gm) in pea and 4.06gm in lentil plants. Plasmids were also analyzed in order to characterize their role in the evolution of rhizobial symbionts and their involvement in symbiotic behaviour. The developed Rhizobium strains with improved symbiotic association and ability to infect across strict specificity for host legumes would be of great help for the farming community at large

Statistical media optimization studies for growth and polydroxybutyrate (PHB) production by Pseudomonas spp.

Using glucose as carbon source and mustard cake and yeast extract as nitrogen sources bacterial isolate Pseudomonas B2 exhibited a maximum PHB recovery of 0.620 (in terms of O.D.) and PHB weight of 0.27g/L in 96 h. To determine the possibility of growth potential of Pseudomonas spp., it was grown in different carbon sources like fructose, glucose, maltose, mannitol etc. and it was found that glucose yielded good growth and PHB production. In order to incorporate cost effective nitrogen and carbon source, mustard cake and cotton cake as nitrogen source and molasses as carbon were used in medium. Statistical media optimization design was used to optimize the culture conditions for maximizing the PHB production. A maximum of 0.37 g/L of PHB and 0.746 (O.D.) PHB recoveries were obtained using optimized concentrations. Batch kinetics can be used for model development, which will make possible simulation of nutrient limited cultivation(s) for over accumulation of PHB. FTIR studies confirmed the presence of PHB