Rengaraju Balakrishnaraja

Polyphenols have gained significant attention in recent decades due to their protective role against cancer, diabetes, obesity, osteoporosis, neurodegenerative, and cardiovascular diseases. This study explored the influence of radiation time, microwave power, and sample-to-solvent ratio on the microwave-assisted extraction of polyphenols from Pithecellobium dulce fruit peels. Extraction efficiency, antioxidant activity, and anti-cholesterol activity were optimised using both response surface methodology (RSM) and artificial neural networks combined with a genetic algorithm (ANN-GA). The ANN-GA model exhibited higher predictive accuracy (R² = 0.9805–0.9813) and lower statistical error compared to quadratic RSM models (R² = 0.9566–0.9767). Under optimised conditions, ANN-GA yielded 244.35 mg/g total polyphenols, 92.51% antioxidant activity, and 73.96% anti-cholesterol activity, outperforming RSM (242.35 mg/g, 92.18%, and 73.26%, respectively). These findings demonstrate the scientific novelty of ANN-GA as a more robust and reliable tool than RSM for process optimisation. Moreover, the study highlights the practical application of utilizing P. dulce fruit peels as a low-cost, natural source of health-promoting bioactives. Importantly, this work presents a broader impact by providing a sustainable strategy for waste valorisation into nutraceutical and pharmaceutical products.

This study investigates the impact of different solvents and extraction methods, such as conventional solvent extraction, solvent extraction (using soxhlet apparatus), and microwave‐assisted extraction (MAE), on the efficiency of extracting phenolic and antioxidant compounds. A Box–Behnken design from response surface methodology (RSM) was used to optimize the MAE process conditions to extract bioactive constituents from Pithecellobium dulce , using water and an aqueous mixture (70 [acetone]/29.5 [water]/0.5 [acetic acid], v/v/v). In addition, an artificial neural network (ANN) was utilized for optimization, whereas Fourier transform infrared spectroscopy characterizes polyphenolic compounds. The results from ANN were found to be more substantial compared to RSM. Optimum conditions for MAE using water are determined to be the powder‐to‐solvent ratio of 26:17 mL and a treatment time of 17–29 s, resulting in the extraction of 586.226 mg GAE/g of total polyphenol content and 93.44% antioxidant activity, higher than that of the aqueous acetic acid mixture. Furthermore, ANN exhibits additional statistical variables and coefficient of determination ( R ² ) for each response. The yields of total polyphenol obtained were 525.94 ± 7.51 mg GAE/g (MAE), 284.43 ± 6.13 mg GAE/g (solvent extraction), and 154.37 ± 2.7 mg GAE/g (conventional solvent extraction). The study concludes that MAE can be an alternative technique to conventional methods to extract polyphenols from leaves with higher yields using water. When considering statistical effectiveness, ANN outperforms response surface methodology.

A simple hydrothermal method is utilized to synthesize iron-doped tin oxide nanoparticles (Fe-SnO₂ NPs) at various doping concentrations. The structural characterization using XRD, Raman, and FTIR measurements confirmed the incorporation of Fe ions into the SnO₂ lattice without any deviation in the tetragonal crystal system of SnO₂ nanoparticles. SEM and HRTEM images show the spherical-shaped nanoparticles with agglomeration. The values of interplanar spacing ([ ]-value) calculated from the HRTEM lattice are consistent with the XRD results. Further, optical analysis revealed a red shift in the optical absorption band and a decrease in the band gap energy with an increase in Fe-dopant concentration. The decrease of PL emission peak intensity with Fe doping revealed the generation of singly charged oxygen vacancies. The H₂O₂-assisted photocatalytic degradation efficiency of Fe-SnO₂ NPs investigated against crystal violet dye indicated an efficiency of 98% for 0.05 M Fe-SnO₂ NPs within 30 minutes under visible light illumination. In addition, the effects of pH, scavengers, and reusability of the catalyst are tested. The antibacterial behavior of Fe-SnO₂ NPs against Escherichia coli is examined by using the colony count method, and the inhibition rate was found to be 49, 65, 70, and 78% for pure, 0.01, 0.03, and 0.05 M Fe-SnO₂ NPs, respectively.

Biofertilizer is a group of beneficial microorganisms used for improving the productivity of soil by fixing atmospheric nitrogen or by solubilizing soil phosphorus. They also stimulate plant growth through synthesis of growth promoting substances. In this present study, Azospirillum lipoferum is grown in Nitrogen free Bromothymol blue (Nfb) medium and Pseudomonas fluorescens in King's B medium. Bioprocess condition was optimized for both of the culture and found that Pseudomonas fluorescens has shown highest growth at 300C in pH 8 after 72 hours of incubation where as Azospirillum lipoferum showed highest cell concentration at 310C in pH 7, with incubation period of 72 hours. The optimized culture is mixed with different formulations of powder and liquid carrier such as Saw dust, Rice husk, Date seed powder, Matka khad, Jiwamrit and Beejamrit respectively. Shelf life study for 0, 30, 60, 90 and 120 days by cell counting and spread plate method showed that shelf life of the biofertilizer produced from Powder and liquid carriers had high amount of viable microbial population up to 120 days storage. Among biofertilizer based bio inoculants, Saw dust showed maximum population of 77x109cfu/ml for Azospirillum lipoferum and 72 x 109 CFU/ml for Pseudomonas strain on 120th day and the liquid carrier Matka khad showed 85x109 cfu/ml for Azospirillum lipoferum and 78 x 109 CFU/ml for Pseudomonas fluorescens.