Atkinson Kincaid (forkbaker7)
The effect of microbial transglutaminase (MTGase) in cross-linking and modifying of rice glutelin-casein blends was investigated in this work. The maximum MTGase activity on rice glutelin-casein blends were found when its addition was 15 U/g of protein. Compared with the blends without MTGase, the appropriate addition of MTGase significantly affected the microstructure of the cross-linked proteins, resulting in the gradual 'burying' of Trp residue; while the space for hydrogen bonding was more abundant. Secondary structure changes, denoted by the disappearance of the α-helix and the decrement of the β-sheet structure, was due to the formation of the large loop and random coil structures. The MTGase-catalyzed reaction improves the protease resistance of the blends but not promote the conversion of free sulfhydryl groups (-SH) to disulfide groups (S-S). All the samples evaluated exhibited Bingham flow behavior instead of shear-thinning behavior, and thermally stable fluid properties dominated by elasticity, regardless of MTGase concentration used. Both the storage modulus (G') and loss modulus (G'') gradually decreased with the addition of MTGase. In short, this work demonstrated how the structure, rheology, digestibility of rice glutelin-casein blends are influenced by MTGase concentration.Probiotic foods and supplements have been shown to offer multiple potential health benefits to consumers. Dried probiotic cultures are increasingly used by the food industry because they are easily handled, transported, stored, and used in different applications. However, drying technologies often expose probiotic cells to extreme environmental conditions that reduces cell viability. Hence, this study aimed to evaluate the effect of using ultra high-pressure homogenization (UHPH) on soymilk's microencapsulating ability, and the resultant effect on the survivability of probiotic Lactobacillus plantarum NRRL B-1927 (LP) during drying. Liquid suspensions containing LP (~109 CFU/g of solids) were prepared by suspending LP cultures in soymilk which had been either treated with UHPH at 150 MPa or 300 MPa or left untreated. LP suspensions were then dried by concurrent spray drying (CCSD), mixed-flow spray drying (MXSD) or freeze-drying (FD). Cell counts of LP were determined before and after microencapsulation. U0126 concentration Moisture, water activity, particle size and morphology of LP powders were also characterized. LP powders produced with 300 MPa treated soymilk had 8.7, 6.4, and 2 times more cell counts than those produced with non-UHPH treated soymilk during CCSD, MXSD, and FD, respectively. In the 300 MPa treated samples, cell survival (%) of LP during drying was the highest in MXSD (83.72) followed by FD (76.31) and CCSD (34.01). Using soymilk treated at higher UHPH pressures resulted in LP powders with lower moisture content, smaller particle sizes and higher agglomeration. LP powders produced via MXSD showed higher agglomeration and fewer signs of thermal damage than powders produced via CCSD. This study demonstrates that UHPH improves the effectiveness of soymilk as a microencapsulant for probiotics, creating probiotic powders that could be used in plant-based and non-dairy foods.In food formulations, lipids are normally incorporated as emulsions stabilized by different types of emulsifiers. The emulsifiers can affect fatty acid (FA) solubilization as they can interact with FA. The main purpose of the present work is the development of a methodology to evaluate the FA solubilization in an aqueous medium in the absence and presence of exogenous emulsifiers. To this end, a combination of turbidimetry, oiling off and dynamic light scattering (DLS) was used. The FA solubility, as well as its supramolecular assemblies, were determined by analyzing the changes in the turbidity profile and the corresponding size of particles obtained by DLS. Oleic acid (OA) was used as a model FA and a simulated intestinal fluid (SIF) as the aqueous pha