Heteroprotein Complex Formation of Bovine Lactoferrin and Pea Protein Isolate: A Multiscale Structural Analysis.

Associative electrostatic interactions between two oppositely charged globular proteins, lactoferrin (LF) and pea protein isolate (PPI), the latter being a mixture of vicilin, legumin, and convicilin, was studied with a specific PPI/LF molar ratio at room temperature. Structural aspects of the electrostatic complexes probed at different length scales were investigated as a function of pH by means of different complementary techniques, namely, with dynamic light scattering, small-angle X-ray scattering (SAXS), turbidity measurements, and atomic force microscopy (AFM). Irrespective of the applied techniques, the results consistently displayed that complexation between LF and PPI did occur. In an optimum narrow range of pH 5.0-5.8, a viscous liquid phase of complex coacervate was obtained upon mild centrifugation of the turbid LF-PPI mixture with a maximum Rh, turbidity and the ζ-potential being close to zero observed at pH 5.4. In particular, the SAXS data demonstrated that the coacervates were densely assembled with a roughly spherical size distribution exhibiting a maximum extension of ∼80 nm at pH 5.4. Equally, AFM image analysis showed size distributions containing most frequent cluster sizes around 40-80 nm with spherical to elliptical shapes (axis aspect ratio ≤ 2) as well as less frequent elongated to chainlike structures. The most frequently observed compact complexes, we identify as mainly leading to LF-PPI coacervation, whereas for the less frequent chain-like aggregates, we hypothesize that additionally PPI-PPI facilitated complexes exist.

Optimization of complex coacervation parameters for the production of encapsulated black garlic using response surface methodology.

The purpose of this study was to optimize black garlic encapsulation parameters (core/coating ratio, extract concentration, and coacervate/maltodextrin [MD] ratio) using central composite design of the response surface methodology based on encapsulation efficiency (EE) (%). The optimum parameters were determined as 4.0 for the coating material/core ratio, 50% for the extract concentration, and 6.0 for the MD/coacervate ratio depending on the EE (%). The antioxidant activity values were determined as 101 and 134 µmol Trolox/100 g dry weight (DW) for the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods, respectively, whereas the total phenolic content was 49 mg gallic acid equivalent/100 g DW for the encapsulated black garlic samples. S-Allyl-l-cysteine (SAC), γ-l-glutamyl-SAC (GSAC), γ-l-glutamyl-(S)-trans-1-propenyl-l-cysteine, and allicin were the organosulfur (OS) compounds determined in the samples. The SAC concentration of the encapsulated black garlic samples was determined as 22.36 mg/g, whereas the GSAC content was found at a lower concentration (0.33 mg/g) compared to SAC. The allicin content was quantified to be 0.31 mg/g. The encapsulated samples were also characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The FT-IR analysis revealed specific functional groups, including hydroxyl, carbonyl, and glycosidic linkage. The interaction between lentil protein isolate and pectin was strong enough to encourage capsule formation as visualized in the SEM images. This study shows the potential of black garlic coacervates as a functional ingredient for the food industry due to their stability, solubility, and preservation of OS and antioxidant compounds.

Determining the Arrhenius Kinetics of Avocado Oil: Oxidative Stability under Rancimat Test Conditions.

Avocado is a highly potential functional fruit with significant health benefits which has high demand for consumption with a preferable taste. The fruit is one of the oil sources that still needs further examination on its probable kinetic behavior and oxidative stability as well as some characteristic behavior to commercialize and increase the market demand as functional oil. Hence, this study was motivated primarily for obtaining the Arrhenius kinetic information about avocado oil to evaluate the oxidative stability and provide predictive information about the shelf life by using the Rancimat method which is an accelerated shelf life test. Specifically, this research paper presents the study of the physical, physicochemical, chemical, and oxidative stability tests with the shelf life expectancy and kinetic property of avocado oil. According to the analyses, avocado oil has 210 days of predicted shelf life at 25 °C. This gives it a greater chance to be considered a good alternative to other oils as well as its antioxidant and phenolic content. According to the findings presented in this study, avocado oil has a very similar profile to olive oil and can be used as an alternative functional oil source.