For the first time, purple corn pericarp (PCP) was converted to polyphenol-rich extract using two-pot ultrasound extraction technique. According to Plackett-Burman design (PBD), the significant extraction factors were ethanol concentration, extraction time, temperature, and ultrasonic amplitude that affected total anthocyanins (TAC), total phenolic content (TPC), and condensed tannins (CT). These parameters were further optimized using the Box-Behnken design (BBD) method for response surface methodology (RSM).
View Article and Find Full Text PDFExtraction is regarded as the most crucial stage in analyzing bioactive compounds. Nonetheless, due to the intricacy of the matrix, numerous aspects must be optimized during the extraction of bioactive components. Although one variable at a time (OVAT) is mainly used, this is time-consuming and laborious.
View Article and Find Full Text PDFUnlabelled: Rheological analysis is commonly used to evaluate mechanical properties in studies of food behavior. However, rheological analysis is often insufficient to describe food texture as evaluated by descriptive sensory analysis. Additionally, traditional rheometry does not account for changes in food behavior as a function of saliva incorporation into the food during mastication.
View Article and Find Full Text PDFThe functionality of whey dispersions, prepared with a modified whey protein concentrate (mWPC) ingredient, was significantly altered after cross-linking with microbial transglutaminase (TGase) upon pH adjustment to 8. Test TGase-mWPC solutions, pH 8, gelled faster than control mWPC dispersions, as measured in real time; whereas, the gelling temperature of pretreated TGase-mWPC samples (37 °C, 2.5 h) increased from 67.
View Article and Find Full Text PDFThe roles of sulfhydryl/disulfide interactions and acid/pepsin hydrolysis on β-lactoglobulin (β-lg) thermal aggregation at acidic pH 3.35 and 2 were studied using rheology, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), transmission electron microscopy (TEM), and Western blotting. Pepsin promoted additional hydrolysis compared to the acid-hydrolyzed control sample based on a 12% increase in free amino groups.
View Article and Find Full Text PDFUnlabelled: Transglutaminase (TGase) cross-linking reactions were accomplished using a heat-modified whey protein concentrate (mWPC) substrate after pH adjustment to 8. Based on earlier reports, the degree of lactosylation with respect to beta-lactoglobulin was lower in mWPC dispersions than measured in commercial whey concentrate (cWPC) protein solutions. In this study, a higher concentration of free sulfhydryl groups was detected in soluble supernatant fractions.
View Article and Find Full Text PDFThe primary objective for this study addressed the effects of supplemental calcium on the functional properties of a modified whey protein ingredient (mWPC), prepared by acidification to pH 3.35, followed by extended heat treatment, gelation, and spray drying. In the presence of added calcium (mWPC-Ca2+), protein solutions showed increased thickening capacity, especially under refrigeration temperatures, compared to dispersions made with mWPC alone.
View Article and Find Full Text PDFThe rheology and microstructure of a rennet casein system were studied in the pH range from 5.8 to 12.0 during cooling from 80 to 5 degrees C at four cooling rates: 0.
View Article and Find Full Text PDFIn vivo studies of jaw-muscle behavior have been integral factors in the development of our current understanding of the primate masticatory apparatus. However, even though it has been shown that food textures and mechanical properties influence jaw-muscle activity during mastication, very little effort has been made to quantify the relationship between the elicited masticatory responses of the subject and the mechanical properties of the foods that are eaten. Recent work on human mastication highlights the importance of two mechanical properties-toughness and elastic modulus (i.
View Article and Find Full Text PDFMicroscopy and permeability studies were performed to further illustrate the cooling effects on rennet casein gel structure and help interpret the rheological observations in the first part of this paper. Samples of gels cooled from 80 to 5 degrees C at four rates (0.5, 0.
View Article and Find Full Text PDFThe gelation of a model rennet casein system was studied during cooling at different rates. During cooling, casein network structure development was proposed to evolve over a few steps at different length scales: molecules, particles, flocs, or network. Rennet casein flocs are fractal in nature, and fractal dimension and floc size are two variables affecting the rheology and microstructure of a rennet casein gel.
View Article and Find Full Text PDF