Optimization of nanofiber-caproate/laurate esters synthesis, their characterization, and usage as emulsifier in o/w emulsion

The aim of this study is to optimize the esterification of nanofibers with caproyl/lauroyl chlorides at different substitution degrees' (DS) and to investigate the usage of nanofiber derivatives in model emulsions. First, cellulosic material was obtained and milled into nanofibers using a micro-fluidizer. Then, these nanofibers were esterified with caproyl/lauroyl chlorides in a solvent of DMAc/LiCl with DMAP as an acid scavenger. The esterification of nanofibers with caproyl/lauroyl chlorides was optimized for fatty acid chloride mole and reaction time. Esterification reactions were carried out at 80 & DEG;C with various molar ratios of acyl chlorides (3-15 moles) versus anhydroglucose unit of nanofibers and for various time durations (30-360 min). The hydrophobic derivatives with DS in the range of 0.34-2.77 were successfully obtained. Using the data obtained as a result of the optimization, nanofiber-fatty acid esters with different DS (0.50-2.75) were produced and characterized. Analyzes showed that the esterification process was successful and as the degree of esterification increased, the crystallinity index and thermal stability of the derivatives decreased. Then, the nanofiber-caproate/laurate esters with different DS were used as emulsifier (0.5 wt%) in an oil-in-water model emulsion containing 25 wt% oil and the emulsions were analyzed. The nanofiber caproate/laurate esters with a DS of 0.50-1.25 were suitable for o/w emulsions, while samples with a DS of 2.00 and above were not found suitable. Emulsions prepared by using nanofiber derivatives with 1.25 DS had higher G & PRIME; and G & DPRIME; and viscosity values and lower droplet sizes than those of other group.Turkish Scientific Council TUBITAK [TOVAG 118O315]Turkish Scientific Council TUBITAK, Grant/Award Number: TOVAG 118O31

Rheological and sensorial behavior of tomato product enriched with pea protein and olive powder

In this study, a new functional product using Mediterranean ingredients (tomato, tomato peel powder and olive powder) was formulated where two different concentrations of protein (1 and 2%) and peel (2 and 4%) were tested. Olive powder was kept at a constant concentration of 2%. Physico-chemical, Rheological, and Sensorial analysis were carried out on the formulated samples. Soluble protein content was found as the highest in the sample containing 4% peel and 2% protein and it was affected by the pH and tomato peel concentration. Rheological results reveal shear-thinning behavior, as defined by the Herschel-Bulkley model, with protein and peel concentrations having a major influence on yield stress and viscosity. A positive trend was noticed between apparent viscosity and peel concentration, meantime protein concentration affected apparent viscosity adversely. Contrary relation between consistency index (k) values and apparent viscosity illustrate the complex interaction between protein and peel, particularly at higher concentrations. Furthermore, Principal Component Analysis (PCA) was used to investigate the complicated sensory landscape of tomato products with different quantities of pea protein and tomato peel. While higher tomato peel and protein levels have no direct impact on rheological qualities, they do add to astringency and sourness, which influences overall acceptability. Remarkably, the sample with the greatest quantities of peel and protein exhibits a delicate balance, with a loss in perceived tomato taste intensity and overall acceptability offsetting an increase in astringency. In terms of overall acceptability, the most preferred beverage was selected as the sample formulated with 2% peel and 1% protein

Novel acoustical and mechanical methods for rheological characterization of the biological materials

Rheological characteristics of a material can be important for wide range of industries including food, chemical, biomedical, pharmaceutical, etc. Four novel methods using acoustical and vibrational principles were developed to meet continuous demand for novel rheological techniques. First, commonly used impedance tube technique was modified and simplified for liquids. It was shown that thick wall impedance tube can be used to measure viscosity related attenuation in liquids. This principle was also applied to the cylindrical shape containers containing selected food samples. Second method was a modified version random frequency squeezing technique. In this study this a new design allowing complex moduli measurements for wide range of frequencies and materials, is provided. In the next method flexural vibrations of the beams with free-free boundary conditions were analyzed as a viscosity sensing tool along with various applications with selected food samples. Finally, a new design using plug flow oscillation of the liquids in cylindrical shape tubes was investigated, CMC solutions at different concentrations were used as model liquids and the results obtained using this method and conventional rheometry were in good agreement