The preferential use of a soy-rapeseed lecithin blend for the liposomal encapsulation of a tilapia viscera hydrolysate

Controlled release and biological properties of prochitosomes loaded with Arthrospira derived peptides: Membrane stability, chemical, morphological and structural monitoring

In this study, the effects of chitosan-coating on maintaining the integrity and stability of the membrane, structural, and morphological changes, and the release of loaded peptides inside nanoliposomes during various in vitro release, thermal, freeze-thaw, shear, and dehydration (spray-drying) tensions were evaluated. Among different peptidic fractions (100, 30, and 10 kDa), the Arthrospira derived PF-30 kDa showed a higher nutritional and biological value. PF-30kDa was loaded successfully (EE ~ 90 %) inside nanoliposomes (NLs) and its stabilization was done with chitosan coating (0.1-0.8 %). Nanochitosomes (NCs-0.4 %) had more structural stability (size, EE, and biological activity) at different temperatures, freeze-thaw tension, and digestive system. The placement of peptides in the vesicle structure was confirmed by FTIR analysis. Also, the changes in the morphological states, agglomeration, or destruction of the liposome membrane (SEM, AFM, and TEM) were evaluated before and after the tensions. Membrane coating led to the transformation of freeze-dried liposomes (FD-NLs) from thin, porous, and fragile layers to thick plates, rough and resistant structures (FD-NCs). These characteristics led to maintaining physical stability, homogeneity, zeta potential, and EE of nanoparticles (freeze and spray-dried) after reconstitution. The results of this study will effectively contribute to the production of solidified delivery systems with long-term durability, bioavailability, and biological activity of loaded nutrients and drugs.

Layer-by-layer self-assembled liposomes fabricated using sodium alginate and chitosan: Investigation of co-encapsulation of folic acid and vitamin E

In this study, we constructed layer-by-layer self-assembled liposomes were prepared using sodium alginate (SA) and chitosan (CS) to co-encapsulate folic acid (FA) and vitamin E (VE). We investigated the morphology structure, stability mechanism and digestive behavior of the liposomes with varying addition mass ratios of FA and VE (3:7, 4:6, 1:1, 6:4, and 7:3). The results showed that the particle size of FA and VE co-encapsulated liposomes (L-FA-VE) increased from 424.54 to 464.27 nm. Compared to liposomes without encapsulated FA and VE (L), L-FA-VE were uniformly distributed and with a clear fingerprint structure. Among the L-FA-VE with different addition mass ratios, L-FA-VE 3:7 exhibited the highest encapsulation efficiency (EE) of 79.54 % and 81.57 % for FA and VE, respectively. Layer-by-layer self-assembled liposomes effectively retarded the degradation of FA and VE under strong acid, alkali, high salt environments and ultraviolet radiation. Additionally, L-FA-VE enhanced the extent of FA and VE release in the simulated gastrointestinal environment (FA: 69.26 %; VE: 83.98 %). These findings are valuable for developing of multi-component nutrient delivery systems using layer-by-layer self-assembled liposomes.

Valorization of Yellowfin Tuna Tails: From Proteolytic Enzyme Production to Gelatin and Antioxidant Hydrolysate Extraction

This study investigates the valorization potential of yellowfin tuna (Thunnus albacares) tails to produce high-value commercial products. Firstly, the tuna tails were placed in a perforated stainless-steel cylinder, and hydraulic pressure was applied to separate the skin from the muscle in the tails. The extracted muscle was then utilized as a nitrogen source for the growth of the proteolytic enzyme producer Bacillus subtilis, while the skins were employed for gelatin extraction. The proteases from B. subtilis were partially purified and used to produce antioxidant peptides from the obtained gelatin. The gelatin formed a gel upon cooling, with gelling and melting temperatures of 16 °C and 22 °C, respectively, and a Bloom strength of approximately 160. Response Surface Methodology (RSM) was employed to determine the optimal hydrolysis conditions to achieve the highest antioxidant activity (35.96% measured as DPPH radical scavenging activity), which were 50 °C and 6.5 IU of enzyme. The findings emphasize the importance of an integrated approach to maximize the value of tuna by-products, promoting sustainability within the framework of a circular bioeconomy. Overall, these results contribute to the efficient utilization of tuna by-products, waste reduction, and enhanced economic viability of the tuna industry.

Protein Hydrolysates from Fishery Processing By-Products: Production, Characteristics, Food Applications, and Challenges

Fish processing by-products such as frames, trimmings, and viscera of commercial fish species are rich in proteins. Thus, they could potentially be an economical source of proteins that may be used to obtain bioactive peptides and functional protein hydrolysates for the food and nutraceutical industries. The structure, composition, and biological activities of peptides and hydrolysates depend on the freshness and the actual composition of the material. Peptides isolated from fishery by-products showed antioxidant activity. Changes in hydrolysis parameters changed the sequence and properties of the peptides and determined their physiological functions. The optimization of the value of such peptides and the production costs must be considered for each particular source of marine by-products and for their specific food applications. This review will discuss the functional properties of fishery by-products prepared using hydrolysis and their potential food applications. It also reviews the structure-activity relationships of the antioxidant activity of peptides as well as challenges to the use of fishery by-products for protein hydrolysate production.

Protection of navy-bean bioactive peptides within nanoliposomes: morphological, structural and biological changes

This study aimed to produce bioactive peptides from navy-bean protein with alcalase and pepsin enzymes (30-300 min) and to load them into a nanoliposome system to stabilize and improve their bioavailability. The degree of hydrolysis and biological activities (scavenging of DPPH, OH, and ABTS free radicals, reducing power, and chelating metal ions) of navy-bean protein were affected by the type of enzyme and hydrolysis time. The average particle size (83-116 nm), PDI (0.23-0.39), zeta potential (- 13 to - 20 mV), and encapsulation efficiency (80-91%) of nanoliposomes were influenced by the type and charge of peptides. The storage temperature and the type of loaded peptide greatly affected the physical stability of nanocarriers and maintaining EE during storage. The FTIR results suggested the effect of enzymatic hydrolysis on the secondary structures of protein and the effective placement of peptides inside polar-regions and the phospholipid monolayer membrane. SEM images showed relatively uniform-sized particles with irregular structures, which confirmed the results of DLS. The antioxidant activity of primary peptides affected the free radical scavenging of loaded nanoliposomes. Liposomes loaded with navy-bean peptides can be used as a health-giving formula in enriching all kinds of drinks, desserts, confectionery products, etc.

Electrically Switchable Nanolever Technology for the Screening of Metal-Chelating Peptides in Hydrolysates

Metal-chelating peptides (MCP) are considered as indirect antioxidants due to their capacity to inhibit radical chain reaction and oxidation. Here, we propose a new proof of concept for the screening of MCPs present in protein hydrolysates for valorizing their antioxidant properties by using the emerging time-resolved molecular dynamics technology, switchSENSE. This method unveils possible interactions between MCPs and immobilized nickel ions using fluorescence and electro-switchable DNA chips. The switchSENSE method was first set up on synthetic peptides known for their metal-chelating properties. Then, it was applied to soy and tilapia viscera protein hydrolysates. Their Cu²⁺-chelation capacity was, in addition, determined by UV-visible spectrophotometry as a reference method. The switchSENSE method has displayed a high sensitivity to evidence the presence of MCPs in both hydrolysates. Hence, we demonstrate for the first time that this newly introduced technology is a convenient methodology to screen protein hydrolysates in order to determine the presence of MCPs before launching time-consuming separations.