Effects of shear and pH on starch phosphates prepared by reactive extrusion as a sustained release agent

Stability and Anti-Aging of Encapsulated Ferulic Acid in Phosphorylated Rice Starch

Ferulic acid (FA) provides broad biological functions that have been used in cosmetics formulation as a photoprotection, anti-aging, and brightening agent. However, its application is limited by its tendency to deteriorate by exposure to heat, humidity, and light. This study aimed to enhance the stability of FA by encapsulation in phosphorylated rice starch (PRS) and evaluate its effect on improving human skin. First, FA was encapsulated in PRS and characterized by FTIR, SEM, XRD, and DSC. Then, its stability when exposed to a temperature of 45 °C and light and its anti-aging effect on 16 volunteers were investigated. The results indicated that FA was successfully encapsulated in PRS with an encapsulation yield of 77%, EE (73%) and LE (65%). After 1 month at the high temperature/80%RH, the encapsulated FA retained its quantity (70%), whereas free FA was retained at only 50%. Under light exposure conditions, the encapsulated FA was retained at 65%, which was higher than FA (35%). Franz diffusion cell was used and demonstrated that PRS provided the controlled release of FA. Application of encapsulated FA and FA creams showed an absence of skin irritation in all volunteers. After 1 month, the encapsulated FA cream was found to be better than the FA cream on skin lightening, elasticity, smoothness, roughness, scaliness, and wrinkle. The results indicated that PRS is a potential wall material for enhancing the stability of FA, resulting in more efficacious skin lightening and anti-aging properties.

Preparation and structural properties of starch phosphate modified by alkaline phosphatase

In this study, a method for the synthesis of starch phosphate using the transferase properties of alkaline phosphatase was explored. Maize starch was treated with a pyrophosphate solution containing alkaline phosphatase and catalytic ions under pH 8 at 37 °C. The synthesis of starch phosphate was evaluated and compared with untreated and treated starch controls. The phosphorus content of the samples increased up to 8500% with the catalytic ion concentration, whereas the peak viscosity by up to 41.4% decreased. The crystallinity and enthalpy of the phosphorylated samples were reduced by up to 26.8% and 23.3%, respectively; however, no significant was observed by Fourier-transform infrared spectrometer. The roughness of the starch surface and the distribution of elemental phosphorus were observed by scanning electron microscopy and energy dispersive Spectrometry. X-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry results further indicated the grafting of the phosphate radical.

Reactive extrusion-processed native and phosphated starch-based food packaging films governed by the hierarchical structure

The aim of this research work was to investigate novel tools given by nanotechnology and green chemistry for improving the disadvantages typically associated to the starch-based films: water susceptibility and brittle mechanical behavior. With this in mind, four food packaging film systems were developed from corn starch or corn starch nanocrystals (SNCs), and modified by phosphating under reactive extrusion (REx) conditions using sodium tripolyphosphate (Na₅P₃O₁₀ - TPP) as a crosslinker. The structural, physicochemical, thermal, rheological and mechanical properties, as well as studies associated with the management of carbohydrate polymer-based plastic wastes (biodegradability and compostability) were carried out in this study. The hierarchical structure and the modification of the starch were dependent on the amylose content and degree of substitution (DS), which in turn depended on the hydrogen (H)-bonding interactions. In both cases, a higher molecular ordering of the starch chains in parallel was decisive to obtain the self-assembled thermoplastic starches. Beyond the valuable results obtained and scientifically analyzed, unfortunately none of the manufactured materials achieved to improve their performance compared to the control film (thermoplastic starch - TPS). It was even thought that the phosphated starch-based films could fertilize lettuce (Lactuca sativa) seedlings during their biodegradation, and this was not achieved either. This possibly due to the low content of phosphorus or its poor bioavailability.

Preparation and characterization of octenyl succinylated normal and waxy starches of maize as encapsulating agents for anthocyanins by spray-drying

The encapsulation by spray drying of maize anthocyanins was evaluated using two types of wall materials, consisting of normal and waxy maize starch, which were esterified with octenyl succinic anhydride. The X-ray diffraction analysis revealed that SWMS possessed a completely amorphous, while SNMS had a crystalline structure. SNMS showed peaks at 2θ = 13.1°, 19.8° and 22.4°. The results revealed that SNMS and SWMS had almost the same encapsulation productivity (EP); SNMS showed the best performance because its EP was higher (95%) than in SWMS (90%). The stability of microcapsules produced with SNMS showed the highest anthocyanin retention after storage in the water activity (aw) range of 0.11-0.94 at 40 °C.