Publicaciones
Seleccione el año que desea consultar:

Burgos-Díaz, C., Opazo-Navarrete, M., Soto-Añual, M., Leal-Calderón, F., Bustamante, M. (2020). Food-grade Pickering emulsion as a novel astaxanthin encapsulation system for making powder-based products: Evaluation of astaxanthin stability during processing, storage, and its bioaccessibility. Food Research International 134.

Link:  https://www.sciencedirect.com/science/article/abs/pii/S0963996920302696

DOI:  https://doi.org/10.1016/j.foodres.2020.109244

Resumen
The use of astaxanthin as a food ingredient is limited due to its poor water solubility in aqueous matrices and highly susceptibility to oxidation; hence microencapsulation of this carotenoid is an appropriate technique to increase its stability and functionally. In this study, astaxanthin oleoresin was encapsulated using a food-grade Pickering emulsion to enhance its stability during spray-drying and storage and its bioaccessibility. The oil-in-water (O/W) emulsions were stabilized by protein-based aggregates obtained from a lupin protein-rich cultivar (AluProt-CGNA). The emulsions containing the astaxanthin microencapsulated in its oil phase (core material) were submitted to a spray-drying process at 160 °C and 140 °C. For this, blends of these protein-based aggregates (LP-APs) and maltodextrin (at different ratios) were used as wall material. The emulsion stability, microstructure, powder characteristics, oxidative stability and concentration of astaxanthin, encapsulation efficiency and bioaccessibility after spray-drying were investigated. The results showed that LP-APs exhibit a great potential to perform as stabilizers for Pickering emulsions. The formed O/W emulsions were highly stable against creaming at high concentrations of LP-APs. The results also indicated that spray-drying can be applied to prepare stable astaxanthin emulsions into powders with good oxidative stability. The astaxanthin content in dry emulsions under storage conditions (25 and 45 °C for 4 weeks) was higher in powders containing a higher LP-APs concentration. The encapsulation efficiency was higher than 90% with the emulsion stabilized with 6% of LP-APs. The bioaccessebility of reconstituted astaxanthin powder (with 6% LP-APs) was around 80%.

Keywords: Pickering emulsions; Protein aggregates; Astaxanthin; Encapsulation; AluProt-CGNA; Lupinus luteus

Claudia E. Osorio, Nuan Wen, Jaime H. Mejías, Shannon Mitchell, Diter von Wettstein and Sachin Rustgi. Directed-Mutagenesis of Flavobacterium meningosepticum Prolyl-Oligopeptidase and a Glutamine-Specific Endopeptidase From Barley. Front. Nutr., 18 February 2020

DOI: https://doi.org/10.3389/fnut.2020.00011

Resumen

Wheat gluten proteins are the known cause of celiac disease. The repetitive tracts of proline and glutamine residues in these proteins make them exceptionally resilient to digestion in the gastrointestinal tract. These indigested peptides trigger immune reactions in susceptible individuals, which could be either an allergic reaction or celiac disease. Gluten exclusion diet is the only approved remedy for such disorders. Recently, a combination of a glutamine specific endoprotease from barley (EP-B2), and a prolyl endopeptidase from Flavobacterium meningosepticum (Fm-PEP), when expressed in the wheat endosperm, were shown to reasonably detoxify immunogenic gluten peptides under simulated gastrointestinal conditions. However useful, these “glutenases” are limited in application due to their denaturation at high temperatures, which most of the food processes require. Variants of these enzymes from thermophilic organisms exist, but cannot be applied directly due to their optimum activity at temperatures higher than 37°C. Though, these enzymes can serve as a reference to guide the evolution of peptidases of mesophilic origin toward thermostability. Therefore, a sequence guided site-saturation mutagenesis approach was used here to introduce mutations in the genes encoding Fm-PEP and EP-B2. A thermostable variant of Fm-PEP capable of surviving temperatures up to 90°C and EP-B2 variant with a thermostability of up 60°C were identified using this approach. However, the level of thermostability achieved is not sufficient; the present study has provided evidence that the thermostability of glutenases can be improved. And this pilot study has paved the way for more detailed structural studies in the future to obtain variants of Fm-PEP and EP-B2 that can survive temperatures ~100°C to allow their packing in grains and use of such grains in the food industry.

Yamira Cepero-Betancourt, Mauricio Opazo-Navarrete. Anja E.M. Janssen, Gipsy Tabilo-Munizaga, Mario Pérez-Wona. Effects of high hydrostatic pressure (HHP) on protein structure and digestibility of red abalone (Haliotis rufescens) muscle

DOI: https://doi.org/10.1016/j.ifset.2019.102282

Link: https://www.sciencedirect.com/science/article/pii/S146685641930699X

Resumen

The seafood industry uses high hydrostatic pressure (HHP) technology to reduce undesirable sensory changes and preserve the functional and nutritional properties of compounds. The HHP experiments contributed to unravel the impact of the different level pressure on digestibility. HHP treatment can change the secondary structures of proteins and improve the protein digestibility as function the pressure level. The results of this study provide valuable information for the potential application of HHP on the development of red abalone with high-nutritional value.

Keywords
High hydrostatic pressure; Abalone; Fourier transform infrared spectroscopy; Protein secondary structure; Digestibility