Re-assembled casein micelles (rCMs) are a unique class of nanostructures with outstanding nanotechnological traits. This study focuses on a semi-automated reassembly procedure for the fabrication of resveratrol-loaded re-assembled casein micelles (Res-rCMs). Encapsulation efficiency of the resveratrol in Res-rCMs was similar to 77 % with a loading capacity of similar to 2.3 % at 1000 mu g mL(-1) of resveratrol in final micellar dispersion, which is similar to 36-fold higher than the solubility of resveratrol in aqueous medium (similar to 28 mu g mL(-1)). The developed rCMs and Res-CMs had an average micelle size of 104 and 118 nm and zeta-potential of -16.26 and -15.87 mV, respectively. Fluorescence, infrared and X-ray diffraction techniques confirmed the interaction and encapsulation of resveratrol in rCMs. Resveratrol entrapped in the rCMs was effectively protected from hostile environmental factors (temperature and UV light), which contributed to its improved retention upon exposure to physical stressors. Under simulated gastrointestinal conditions, Res-rCMs showed promising bioaccessibility of resveratrol. The outcomes of the current study will provide insight into direct incorporation of resveratrol in dairy products through encapsulation in re-assembled casein micelles.

This study aimed to probe an effective approach to reduce the allergy of ll-lactoglobulin (llLg) by formation of protein corona on starch nanoparticles (SNPs) and unveil the role of ultrasound in temperature-dependence SNPs-llLg coronas systematically through the llLg adsorption mechanism, changes in secondary structure and physicochemical properties. The adsorption was found to be a spontaneous process that negatively correlate with temperature, while, sonication increased the theoretical maximum binding number of llLg from 4600 to 7800, accompanied with higher binding affinity (Ka) of 58 x 106 M-1 and greater change in secondary structure of llLg with 22 +/- 3.1% of ll-sheet. Functionally, ultrasound facilitated the functional properties changes to llLg induced by adsorption to SNPs that inhibited llLg's immunoglobulin E (IgE) combining capacity for 87 +/- 5%, decreased surface hydrophobicity and digestibility due to the more decrease of ll-sheet, whereas, increased thermal stability and emulsifying ability. These findings promoted the application potential of llLg and SNPs in food.

The uncovering of single peptides derived from food sources that can form hydrogels is of great relevance for several applications. However, identifying single peptide hydrogels from food is a daunting task given the complex nature of the food systems. The proof of concept of the applicability of TANGO, a statistical mechanical -based algorithm that predicts the b -aggregate propensity of peptides, as a tool to uncover peptides derived from milk that can form hydrogels is reported. Using TANGO in conjunction with a set of defined criteria we discovered that from a group of thirteen peptides derived from milk proteins, seven formed hydrogels at a concentration of 2 wt% and pH 7 at room temperature. Three more peptides formed aggregates and appeared to go through the syneresis process, and three additional peptides remained liquid under the experimental conditions. This result sets the basis of a simple methodology for unveiling peptide hydrogels from food and other natural sources. (c) 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY -NC license (http://creativecommons.org/licenses/by-nc/4.0/).

Natural cross-linkers are extensively employed due to their low toxicity and biocompatibility benefits. Genipin acts as a precursor for producing blue colorants. The formation of these colorants involves the cross-linking reaction between genipin and primary amines present in amino acids, peptides, and proteins. Genipin is extracted from Gardenia jasminoides and Genipa americana. This article explains the cross-linking mechanism of genipin with proteins/polysaccharides to provide an overall understanding of its properties. Furthermore, it explores new sources of genipin and innovative methodologies to make the genipin recovery process efficient. Genipin increases food products' texture, gel strength, stability, and shelf life. The antibacterial, antiinflammatory, and antioxidant properties of chitosan, gelatin, alginate, and hyaluronic acid increased after genipin cross-linking. Lastly, drawbacks, toxicity, and directions regarding the genipin cross-linking have also been addressed. The review article covers how to recover and cross-link genipin with biopolymers for industrial applications.

In a recent paper (Li, Li, Zhao, Cui, & Hemar, 2023) we showed that it was possible to manufacture lotus seed milks (LSM) and to use Glucono- delta -lactone (GDL) to prepare LSM acid -gels. LSM milks are known to have a very low lipid content, thus here the effect of soya oil addition is investigated in order to understand how LSM fortification with oil can affect its viscosity, and the mechanical and structural properties of the acid LSM gels. The oil was homogenized under conditions which resulted in oil droplets sizes in the range 0.1 - 0.4 mu m. Heating the emulsions (80 degrees C, 30 min) resulted in a slight increase in particle size due to coalescence. The viscosity of emulsions was quasi -Newtonian and increased markedly with the increase in oil concentration. This was explained partly by the adsorption of the LSM aggregates at the interface of oil droplets, which increases considerably the effective volume fraction of the oil droplets. LSM emulsions when acidified by GDL formed colloidal gels with oil droplets embedded in the protein network, where the syneresis decreased with oil concentration, suggesting that the oil droplets should be considered as active fillers. The gel strength increased linearly with the oil concentration, but with a higher rate for the unheated emulsions than the heated ones. This is due to the decrease in the oil droplets number because of coalescence. This study demonstrates that homogenization of oil into LSM offers a route to manipulate the physico-chemical properties of the LSM emulsions and their acid gels.

Re-assembled casein micelles (rCMs), were formulated in the 1970s as a model system to understand native casein micelles (nCMs) in milk. These early works allowed an understanding of the critical factors involved in the formation of rCMs, such as minerals (citrate, phosphate, and calcium), casein type (αs-, β-, and κ-casein) and the extent of their phosphorylation. rCMs were also used to understand the effect of treatments such as ethanol, high hydrostatic pressure and heating on the stability and integrity of the micelles. More recently, the applications of rCMs have been investigated, these include their use as a nanocarrier of bioactive molecules and as electrode-bound substrates to monitor chymosin activity by electrochemistry, to cite a few. Moreover, the potential to use rCMs in both food and non-food applications remains to be fully exploited. The advantage of choosing rCMs over nCMs as an encapsulant and a lucrative food ingredient is due to their more efficient preparation and being free from impurities. In this review, we report on the formulation of rCMs, their physico-chemical properties and their behavior under different physico-chemical treatments, along with the applications and challenges of rCMs in food systems and their industrial production as a dairy ingredient.

The physicochemical and acid gelation properties of lotus seed milks (LSMs), total solid concentrations varying from 5 to 20 wt%, were investigated in comparison with bovine skim milk (10 wt%). LSM was prepared by soaking, blending and milling, filtering followed by alpha-amylose treatment to hydrolyse the starch in order to reduce its viscosity. The particle size of LSM revealed a multimodal distribution with two main size distributions, a smaller one (similar to 0.06 and similar to 1.5 mu m) from protein aggregates as a result of the heat treatment and a larger one (similar to 1.5 mu m and similar to 250 mu m) likely due to the presence of undissolved protein and cellular materials. A slight shift toward higher sizes, due to further protein denaturation, can be observed after heating at 80 degrees C for 30 min. As expected, the viscosity of LSM depended on the total solid concentration, and was found to be similar to that of the skim milk when the LSM concentration was around 5 wt%. Addition of glucono-delta-lactone resulted in the formation of LSM gels, and the gelation of LSM occurred when the pH decreased to similar to 6 while that of skim milk occurred at pH 5.2. Small deformation rheological measurements showed that it is possible to obtain a LSM acid -gels similar in viscoelastic behaviour (complex modulus G*approximate to 300 Pa after 5 h acidification) to 10 wt% skim milk gel when the concentration of LSM is about 11.1 wt% (same dietary energy as skim milk). Confocal laser scanning microscopy showed that a similar microstructure to skim milk gel is observed for 5 wt% LSM gel, while a denser protein network with voids were observed at high LSM concentrations. The colour of these milk gels appeared white under the naked eye and their syneresis decreased sharply with the increase in concentration with a syneresis similar to that of skim milk when LSM concentration was >= 15 wt%. This study suggested for the first time the potential of LSM to be a strong alternative for the manufacture of non-animal acid milk gels.

Starch nanoparticles (SNPs) were synthesized and characterized in vivo for their subacute biotoxicity. Animal experiments revealed that SNPs would not induce changes in inflammatory cytokines and gut microbiota, avoiding damage to mice's organs. Moreover, SNPs were rapidly excreted from the body after 6 h without any accumulation, demonstrating their biosafety. Based on these findings, SNPs were used for beta-lactoglobulin (beta Lg) desensitization by formation of a protein corona. The thermodynamics and time evolution of beta Lg's secondary structure were investigated to address the desensitization mechanism. The results showed-1600 beta Lg molecules onto a single SNP coupled with significant changes in secondary structure formed a stable SNPs-beta Lg corona with binding affinity (Ka) of 8.4 +/- 0.5 x 105 M- 1. Functionally, the decrease of beta-sheet destroyed the conformation of immunoglobulin E (IgE) epitopes and inhibited IgE combining capacity, achieving SNPs' desensitization to beta Lg. Additionally, it takes-2 h to complete changes in beta Lg's surface hydrophobicity and immunoglobulin E (IgE) combining capacity after incubation with SNPs, consistent with the time evolution of structure changes, indi-cating protein corona is response for the desensitization.

In vitro coagulation and digestion of caprine and bovine micellar casein concentrate (MCC) with or without partial colloidal calcium depletion (deCa) were studied under simulated adult and elderly conditions. Gastric clots were smaller and looser for caprine than bovine MCC, and were further looser with deCa and under elderly condition for both caprine and bovine MCC. Casein hydrolysis and concomitant formation of large peptides was faster for caprine than bovine MCC, and with deCa and under adult condition for caprine and bovine MCC. Formation of free amino groups and small peptides were faster for caprine MCC, and with deCa and under adult condition. Upon intestinal digestion, proteolysis occurred rapidly, and was faster under adult condition, but showed less differences with increasing digestion between caprine and bovine MCC, and with and without deCa. These results suggested weakened coagulation and greater digestibility for caprine MCC and MCC with deCa under both conditions.

70% (v/v) concentrated emulsion has been prepared using Ca2+-cross-linked sodium caseinate particles (Ca-CAS) or Ca-CAS coated nano-sized primary emulsion droplets as emulsifiers. The primary droplet-stabilised emulsion (DSE) was compared with the conventional Ca-CAS stabilised-emulsion (PSE) in terms of viscoelasticity as affected by aging (30 days) and heating (80 degrees C, 30 min) at pH 5.8 and 7.0. DSE at pH 5.8 showed the highest complex modulus (G* = 1174 +/- 39 Pa), approximately was six-times higher than other emulsions (G* <=-250 Pa) due to the thick emulsifier layer consisting of primary droplet increasing the effective volume faction of core droplets by a factor of-1.21. After aging, G* of DSE at pH 5.8 increased to 1685 +/- 68 Pa, while G* of other three emulsions were-400 Pa. After heating, G* of DSE reached 1801 +/- 69 Pa and 1312 +/- 205 Pa at pH 5.8 and pH 7.0, respectively, while G* of PSE were-600 Pa at both pHs. The possible mechanism for aging-induced gelation was the gravity-driven microphase separation, in which the droplets flocculate together with the entrapped aqueous phase increasing the effective volume fraction. The heat-induced gelation was attributed to the increase in droplet interactions through protein aggregates and/or primary droplets forming three-dimensional networks at elevated temperature. This study suggests that the mechanical strength of food-grade concentrated emulsions can be effectively improved using nano-sized primary emulsions as emulsifying agent and can be further modulated by aging or heating, which will be useful for developing semi-solid emulsion-based products.

Milks from small ruminant animals, such as goat and sheep, have gained increasing interest from the industry for the manufacture of various dairy products such as yoghurts. Heat treatment of milk is typically applied to improve the yoghurt texture. Here, time-resolved ultra-small angle neutron scattering (USANS) and small-angle neutron scattering (SANS) were employed to probe in situ the microstructural evolution of cow, goat, and sheep milks in D2O during acidification as affected by the heat treatment. Milk gelation can be envisaged as the progressive aggregation of the building blocks (casein micelles) in a fractal manner, which leads to the formation of micron scaled (-3-10 mu m) protein agglomerates. The heat treatment considerably enhanced the gelation of all milks, which is reflected by a faster increase in the fractal dimensions and aggregate sizes. For all three types of milks, similar final plateau fractal dimensions were observed for unheated (-2.2-2.4) and heated milks (-2.4-2.5), suggesting similar mass fractal microstructures in the size range probed by USANS. The final storage modulus after 10 h (G ' final) follow the order of heated sheep milk approximate to sheep milk approximate to heated cow milk > cow milk > heated goat milk > goat milk. The colloidal calcium phosphate (CCP) dissolution kinetics tracked by SANS followed a similar trend as the evolution of the sample acidity (pD-value) and are not significantly affected by the types of milk or the heat treatment. This study shows a great potential of using time resolved USANS and SANS to investigate the microstructural evolution of protein aggregation and gelation.

Lotus seed starch has high apparent amylose content (AAM). A representative definition of its granular architecture (e.g., lamellar structure) remained absent. This study defined the granular shape, crystalline and lamellar structures, and digestibility of twenty-two samples of lotus seed starch (LS) by comparing with those of potato and maize starches. LS granules had more elongated shape and longer repeat distance of lamellae than potato and maize starch granules. The enzymatic susceptibility of LS granules was more affected by AAM than granular architecture. Using these LSs as a model system, the relationships between lamellar structure of starch granules and properties of their gelatinized counterparts were investigated. In LSs, thinner amorphous lamella and thicker crystalline lamella were associated with higher swelling power and yield stress. The relationships were found to be connected via certain structural characteristics of amylopectin.

High Fisher ratio oligopeptides (HFOPs) with molecular weight range from 100 to 800 Da derived from whey protein isolate (WPI) were used to prevent the allergic response induced by beta-lactoglobulin (beta Lg) in vivo due to their anti-inflammatory activities to lipopolysaccharide (LPS) treated RAW 264.7 cells and anti-allergic pro-perties to anti-DNP mouse IgE sensitized RBL-2H3 cells in vitro. The results showed the overexpressed immu-noglobulin E (IgE), unbalanced Th1-/Th2-type immune cytokines and inflammatory factors in beta Lg-allergic mice were significantly attenuated by oral administration of HFOPs, resulting in the prevention of inflammatory le-sions in spleen and colonic histopathology. Moreover, HFOPs increased ratio of Bacteroidetes/Firmicutes at phylum level in sensitive mice, and improved the abundance of Lactobacillaceae at family level to maintain oral tolerance against beta Lg and prevented allergic response. The use of HFOPs may provide a potential alternative for preventing the milk allergy induced by WPI.

The conjugation of chitopentaose (CHP) on β-lactoglobulin (βLg) via Maillard reaction was used to desensitize βLg. The stable βLg-CHP conjugate (βC-4) was formed at 4 h incubation, which contains 5 CHP attached molecules and a conjugated degree of 42 %. The conjugation promoted the thermal stability and emulsifying properties of βLg, and inhibited the immunoglobulin E (IgE) combining capacity by decreasing the content of β-sheet in βLg. Moreover, βLg-CHP conjugates were imparted with anti-oxidant properties and anti-inflammatory activities. Further, the combined action of inhibited IgE combining capacity and anti-inflammatory activities improved the allergy desensitization in βLg sensitized mice. The results showed that overexpressed IgE and inflammatory factors, unbalanced Th1-/Th2- immune cytokines were significantly attenuated after βLg was conjugated with CHP, avoiding the inflammatory lesions in spleen and colon. Additionally, the adverse changes in gut microbiota were alleviated in βC-4 group with a decrease of Bacteroidetes and increase of Firmicutes at phylum level and the probiotic bacteria of Lactobacillaceae was significantly improved at the family level. Thus, the conjugation of CHP can desensitize allergic reaction caused by βLg.

Current understanding of physicochemical properties of lotus seed starch (LS) is scarce partly due to its largely unknown molecular structure. This study compared the physicochemical and molecular characteristics of LSs of a wide collection to those of conventional starches (potato (PS) and maize starches (MS)). Variations were found in the chemical composition, physicochemical properties, and molecular structure of LSs. Amylose content and weight-based ratio of short to long chains of amylopectin (APS:APL) were principal factors affecting the physicochemical properties of LSs from different origins. Compared with PS and MS, LSs had higher gelatinization temperatures, lower amylose leaching, and faster retrogradation. These unique properties of LSs were related to their molecular structure and chemical composition. LSs had higher amylose contents than PS and MS as evaluated by various methods. A majority of amylose chains in LS were longer than those in MS but were shorter than those in PS. The APS:APL of LSs were higher than that of MS but lower than that of PS. The results provided a structural basis for understanding the properties of LS and suggested that this unconventional starch may be complementary to conventional starches for industrial applications.

Herein, 1 wt% quinoa protein isolate (QPI) was exposed to sonication using a 20 kHz ultrasonicator equipped with a 6 mm horn (14.4 W, 10 mL, up to 15 min) or high hydrostatic pressure (HHP, up to 600 MPa, 15 min) treatments at pH 5, pH 7, and pH 9. The changes to physicochemical properties were probed by SDS-PAGE, FTIR, free sulfhydryl group (SH), surface hydrophobicity (H0), particle size and solubility. As revealed by SDS-PAGE, substantial amounts of 11S globulin participated in the formations of aggregates via SS bond under HHP, particularly at pH 7 and pH 9. However, protein profiles of QPI were not significantly affected by the sonication. Free SH groups and surface hydrophobicity were increased after the sonication treatment indicating protein unfolding and exposure of the embedded SH and/or hydrophobic groups. An opposite trend was observed in HHP treated samples, implying aggregation and reassociation of structures under HHP. HHP and sonication treatments induced a decrease in ordered secondary structures (random coil and β-turn) accompanied with an increase in disordered secondary structures (α-helix and β-sheet) as probed by FTIR. Finally, the sonication treatment induced a significant improvement in the solubility (up to ∼3 folds at pH 7 and ∼2.6 folds at pH 9) and a reduction in particle sizes (up to ∼3 folds at pH 7 and ∼4.4 folds at pH 9). However, HHP treatment (600 MPa) only slightly increased the solubility (∼1.6 folds at pH 7 and ∼1.2 folds at pH 9) and decreased the particle size (∼1.3 folds at pH 7 and ∼1.2 folds at pH 9). This study provides a direct comparison of the impacts of sonication and HHP treatment on QPI, which will enable to choose the appropriate processing methods to achieve tailored properties of QPI.

The effect of ionic strength on the heat-induced gelation of quinoa protein isolates (QPI) at pH 7 was investigated. The gelation behaviour and gel strength were characterised by oscillatory rheology. The microstructural characteristics of QPI solutions and gels were probed by ultra-small angle neutron scattering (USANS), smallangle X-ray and neutron scattering (SAXS, SANS), and confocal laser scanning microscopy (CLSM). This suite of techniques provided structural details covering a wide range of length scales from tens of micron to nanometre. It was found that the gelation temperature decreased from 73 degrees C to 40 degrees C and the G* (1 Hz) increased from -67 Pa to -1285 Pa with increasing concentration of NaCl from 0 to 200 mM. A particle size of -32 angstrom and -57 angstrom was identified within the QPI gel containing 0-200 mM NaCl from SAXS and SANS, respectively and whose size decreased upon addition of CaCl2. For all QPI samples, heat treatment promoted protein aggregation on the micron scale, while a larger structural unit (Rg- 170 nm) was kept intact as revealed by USANS. A similar mass fractal structure (df = 2) was observed in the QPI gels containing 0-200 mM NaCl, while CaCl2 addition caused the formation of large protein agglomerates (Rg-2.5-4.0 mu m) with a more compact and denser structural organisation (df = 2.5) inside the protein blobs. CLSM showed that the QPI gels containing CaCl2 are prone to phase separation. Overall, this finding shows the thermal gelation behaviour of QPI can be modulated by the ion type and concentration, which is similarly observed in other globular protein systems. These results provide useful information for the design and preparation of quinoa gels for food applications.

Quinoa starch granular structure as affected by nonenyl succinic anhydride (NSA) substitution was investigated by multiple approaches, including scattering, spectroscopic, and microscopic techniques. The modification had little impact on the morphology of starch granules. The NSA substitution was found mainly in the amorphous lamellae and amorphous growth rings. The NSA modification increased the thickness of the amorphous lamellae. The homogeneity of the ordered structure in the granules was improved, probably because the NSA modification reduced the amount of defects in the semi-crystalline growth ring. Compared to other chemical modifications such as acylation, succinylation was more effective in modifying the starch lamellar structure. A possible reaction pattern of NSA modification on quinoa starch is proposed, in which the NSA modification may follow the sequence of amorphous growth rings, the amorphous matrices among blocklets, amorphous and crystalline lamellae in semi-crystalline growth rings. This study provides new insights on the structural changes of starch granules induced by succinylation on the supramolecular level.

The structure of sodium caseinate particles, as affected by the presence of calcium ions (Ca2+), in aqueous solution and in oil (toluene)-in-water emulsion, was investigated by small-angle X-ray and neutron scattering (SAXS and SANS). SAXS analyses indicated that the sodium caseinate was small particles with a hydrodynamic diameter (Dh) of ~ 12 nm. In the presence of Ca2+, the caseinate particles aggregated as large particles with Dh > 100 nm as determined by dynamic light scattering. The networks within the large particles were self-assembled from the small Ca2+-cross-linked particles (Rg ~ 6.5‒8.0 nm), as probed by SAXS. The fractal dimension increased from 2.5 to 3.4 with increasing protein and CaCl2 concentrations, suggesting a denser structure. The integrity of the caseinate particles at the oil-water interface was enhanced by Ca2+ cross-linking, as observed by transmission electron microscopy. The oil‒water interface stabilised by Ca2+-cross-linked caseinate particles was ~ 30 nm thick, six times thicker than that stabilised by sodium caseinate (~ 5 nm) as analysed by SANS with contrast variation technique. Quantifying the structure of sodium caseinate in an aqueous solution and at the oil-water interface provides valuable insights for designing new casein-based functional materials.