Synthesis of Silver Nanorods from Food Industrial Waste and Their Application in Improving the Keeping Quality of Milk

A novel method for the synthesis of silver nanorods is reported, in which industrial milk waste was utilized, that were then used to extend the stability of milk. During the synthesis, the size of the silver nanorods were affected by pH and temperature. Silver nanorods were formed at alkaline pH in room temperature, whereas nanoparticles were formed in lower pH at elevated temperature. The obtained nanostructures were characterized by UV–visible spectrophotometer, energy dispersive X-ray analysis (EDAX), and transmission electron microscope (TEM). These silver nanorods were used to control coliform and standard plate count (SPC) in milk. This was confirmed by an increase in 4 to 5 folds of methylene blue reduction time as compared to the control. The Hom inactivation model was proposed to express microbial inactivation in milk. The cytotoxic effect of silver nanorods shows that they have been nontoxic to humans even at higher concentration

Optimization of Extraction Process and Kinetics of <i>Sterculia foetida</i> Seed Oil and Its Process Augmentation for Biodiesel Production

This article reports optimization and kinetic studies on extraction of <i>Sterculia foetida</i> seed oil and process optimization for biodiesel production from the same. The oil extraction follows first-order kinetics, and the yield was found to reach a maximum of 55.58 wt % for a 1:12 seed-to-hexane weight ratio. The activation energy and activation thermodynamic parameters at 338 K were determined as <i>E</i>_a = 69.441 kJ mol^–1, Δ<i>H</i>^‡ = 66.63 kJ mol^–1, Δ<i>S</i>^‡ = −238.07 J mol^–1 K^–1, and Δ<i>G</i>^‡ = 147.09 kJ mol^–1. Complete physicochemical properties of the oil were analyzed using standard methods. The low acid value of 0.42 mg of KOH g^–1 for fresh oil enables alkali catalytic transesterification. Different biodiesel production parameters including methanol-to-oil molar ratio, catalyst concentration, and reaction temperature were examined. An optimum yield of 95.4 wt % with a conversion of 98.91% was achieved at values of 6:1, 0.9 wt %, and 338 K, respectively. The fuel properties of the produced biodiesel were compared with the ASTM D6751 biodiesel standard