Impact of glucose polymer chain length on heat and physical stability of milk protein-carbohydrate nutritional beverages

Ultra-high temperature (UHT) stability of chocolate flavored high protein beverages

The effects of two milk protein formulations and κ-carrageenan concentration (0, 0.01, 0.03, and 0.05%) on UHT (145 °C) fouling behavior and physical properties of chocolate flavored high protein beverages were studied. These two beverage formulations were: (i) reconstituted milk protein concentrate (RMPC-Choco) and (ii) RMPC and reconstituted whey protein concentrate (C:W-Choco). The UHT run times for samples prepared without κ-carrageenan were very short (9.5 ± 0.71 and 26.5 ± 2.12 min for RMPC-Choco-0 and C:W-Choco-0, respectively) due to settlement of cocoa powder particles inside the UHT plant leading to severe fouling. The κ-carrageenan requirement for UHT stable (UHT run times > 120 min) RMPC-Choco and C:W-Choco was 0.03 and 0.01%, respectively. The presence of higher amounts of whey proteins in C:W-Choco lowered its κ-carrageenan requirement to render it UHT stable due to additional gelation of whey proteins. This additional gelation was evident from larger average particle sizes and higher viscosity of UHT treated C:W-Choco samples at κ-carrageenan concentrations similar to RMPC-Choco samples. PRACTICAL APPLICATION: This research can be helpful to the food industry when formulating chocolate flavored high protein beverages; their protein profiles can be modified to lower the amount of stabilizers required to make them UHT stable.

Fabrication of ultra-small nanocrystals by formation of hydrogen bonds: In vitro and in vivo evaluation

Poor water solubility and low bioavailability hinder the clinical application of about 70% of newly synthesized compounds. Nanocrystal technology has become a preferred way to improve bioavailability by improving solubility. However, it remains challenging to produce nanocrystals with ultra-small particle sizes to further enhance the extent of bioavailability. Herein, we constructed ultra-small puerarin nanocrystals (Pue-NCs) (20-40 nm) via formation of hydrogen bond during HPH. We confirmed the formation of hydrogen bonds by ¹H NMR and FTIR, and observed the distribution of polymer chains by SEM and TEM. The absorption mechanisms were studied in Caco-2 cell monolayers, and the results showed that the major transport mechanism for puerarin was passive diffusion, meanwhile, for Pue-NCs, the passive transport and micropinocytosis-mediated endocytosis coexisted. The absolute bioavailability of Pue-NCs was 35.28%, which was 11.54 folds compared to that of puerarin. Therapeutic equivalence was demonstrated between Pue-NCs and puerarin injection at 50 mg/kg and 15 mg/kg, respectively, in isoproterenol-induced myocardial ischemia model. This study provides a novel strategy for preparing ultra-small nanocrystals by HPH to increase bioavailability of poorly soluble drugs.

Evaluation of Models for Temperature-Dependent Viscosity Changes in Dairy Protein Beverage Formulations During Thermal Processing

Rheological modeling as a function of temperature is a useful tool for describing products undergoing thermal processing. The rheological behavior of a range of dairy-based (4%, w/w) protein beverages was investigated for applicability to semi-empirical temperature-dependent viscosity equations. The viscosity at 16.8 rad/s of the beverages was measured during heating, holding, and cooling over a temperature range of 25 to 90 ^o C using a rheometer with starch pasting cell geometry. Five established fitting methods were applied based on the Arrhenius and Williams-Landel-Ferry (WLF) equations using nonlinear regression analysis. A two-parameter WLF (WLF₂ ) model, using viscosity at a reference temperature of 25 ^o C resulted in high R² values (0.974 to 0.988) and a statistically superior fit compared to the Arrhenius, Generalized Arrhenius, and exponential equations (P < 0.001). Deviation from the WLF₂ modeled equation was used to describe and investigate the effect formulation had on the changes in viscosity during thermal heating. This study successfully applied the WLF equation to a liquid protein system, proving that a consistent and close fit can be achieved across a range of formulations. A rapid, quantitative method for viscosity-temperature profile evaluation is presented, which can ease product development and optimization of product processing stability.

PRACTICAL APPLICATION

This study validated the use of the Williams-Landel-Ferry equation to describe the behavior of dairy beverages during thermal processing, providing a better fit to rheological data than the widely used Arrhenius-based equations. In conjunction with the WLF equation, a method was presented which reduced the complex rheological data to a single value, which can aid in the comparison of formulations for product development and optimization in both research and industry.