Milk-derived exosome nanovesicles: recent progress and daunting hurdles.

Raw milk is the foundation of quality and safety in the dairy industry, and improving milk source management is the fundamental guarantee. Milk-derived exosomes (MDEs) are nanoscale information transfer molecules secreted by mammary cells with unique content and high stability, which can be used not only as potential markers to analyze key traits of lactation, reproduction, nutrition and health of animals, but also help farm managers to take timely interventions to improve animal welfare, milk quality, and functional traits. Our review first outlines the latest advances in MDEs isolation and purification, compositional analysis and characterization tools. We then provide a comprehensive summary of recent applications of MDEs liquid biopsy in breed selection, disease prevention and control, and feeding management. Finally, we evaluate the impact of processing on the stability of MDEs to offer guidance for dairy production and storage. The limitations and challenges in the development and use of MDEs markers are also discussed. As a noninvasive marker with high sensitivity and specificity, the MDEs-mediated assay technology is expected to be a powerful tool for measuring cow health and raw milk quality, enabling dynamic and precise regulation of dairy cows and full traceability of raw milk.

Nonenzymatic glycation as a tunable technique to modify plant proteins: A comprehensive review on reaction process, mechanism, conjugate structure, and functionality.

Plant proteins are expected to become a major protein source to replace currently used animal-derived proteins in the coming years. However, there are always challenges when using these proteins due to their low water solubility induced by the high molecular weight storage proteins. One approach to address this challenge is to modify proteins through Maillard glycation, which involves the reaction between proteins and carbohydrates. In this review, we discuss various chemical methods currently available for determining the indicators of the Maillard reaction in the early stage, including the graft degree of glycation and the available lysine or sugar, which are involved in the very beginning of the reaction. We also provide a detailed description of the most popular methods for determining graft sites and assessing different plant protein structures and functionalities upon non-enzymatic glycation. This review offers valuable insights for researchers and food scientists in order to develop plant-based protein ingredients with improved functionality.

Dairy products and constituents: a review of their effects on obesity and related metabolic diseases.

Obesity has become a global public health problem that seriously affects the quality of life. As an important part of human diet, dairy products contain a large number of nutrients that are essential for maintaining human health, such as proteins, peptides, lipids, vitamins, and minerals. A growing number of epidemiological investigations provide strong evidence on dairy interventions for weight loss in overweight/obese populations. Therefore, this paper outlines the relationship between the consumption of different dairy products and obesity and related metabolic diseases. In addition, we dive into the mechanisms related to the regulation of glucose and lipid metabolism by functional components in dairy products and the interaction with gut microbes. Lastly, the role of dairy products on obesity of children and adolescents is revisited. We conclude that whole dairy products exert more beneficial effect than single milk constituent on alleviating obesity and that dairy matrix has important implications for metabolic health.

Traditional fermented soybean products: processing, flavor formation, nutritional and biological activities.

Traditional fermented soybean food has emerged as an important part of people's dietary structure because of the unique flavors and improved health benefit. During fermentation, the nutrients in soybean undergo a series of biochemical reactions catalyzed naturally by microorganism secreted enzymes. Thereafter, many functional and bioactive substances such as bioactive peptides, unsaturated fatty acids, free soy isoflavones, vitamins and minerals are produced, making fermented soy products more advantageous in nutrition and health. This review comprehensively discusses the historical evolution, distribution, traditional fermentation processing, main sources and characteristics of fermented strains, flavor components, nutritional properties, and biological activities of four traditional fermented soybean foods including douchi, sufu, dajiang, and soy sauce. In the end, we introduce four major challenges encountered by traditional fermented soybean foods including high salt content, formation of biogenic amine, the presence of pathogenic microorganisms and mycotoxins, and quality inconsistency. We conclude that the establishment of scientific quality standard and innovated fermentation processing is the potential solutions to combat the issues and improve the safety of traditional fermented soybean products.

Modification of pulse proteins for improved functionality and flavor profile: A comprehensive review.

Consumers' preference to have a healthy eating pattern has led to an increasing demand for more nutrient-dense and healthier plant-based foods. Pulse proteins are exceptional quality ingredients with potential nutritional benefits, and might act as health-promoting agents for addressing the new-generation foods. However, the utilization of pulse protein in foods has been hampered by its relatively poor functionality and unpleasant flavor. Protein structure modification has been proved to be a useful means to improve the functionality and flavor profile of pulse protein. This paper begins with a brief introduction of hierarchical structure of pulse protein materials to better understand the structure characteristics. A comprehensive review is presented on the current techniques including chemical and enzymatic modifications and molecular breeding on pulse protein structure and functionality/flavor. The mechanism and the limitations and the toxicological concerns of these approaches are discussed. We conclude that understanding protein structure-functionality relationship is extremely valuable in tailoring proteins for specific functional outcomes and expanding the availability of pulse proteins. Furthermore, selective protein modification is a valuable in-depth toolkit for generating novel protein constructs with preferable functional attributes and flavor profiles. Innovative structure modification with special focus on the molecular basis for the exquisite protein designs is a pillar of pulse protein access to the desired functionality.

Phenolic compounds in germinated cereal and pulse seeds: Classification, transformation, and metabolic process.

Natural phenolic compounds are rich in cereal and pulse seeds and their dietary functions tend to improve dramatically during germination. This article reviews recent research on the transformation of phenolic compounds during seed germination. In particular, it highlights the classification of crude phenolic compounds that can be divided into extractable and non-extractable phenolic compounds based on the biosynthesis process and extraction method. It also recommends grouping resorcinol lipids in the category of extractable phenolic compounds as non-polar solvent extractable phenolic compounds. Moreover, it discusses the variation of the different form of phenolic compounds and proposes a possible metabolic model of these phenolic compounds for seeds germination. This article is crucial for phenolic compounds research, cereal and pulse seeds germination, and food ingredients industry.

Viability of Lactobacillus rhamnosus GG microencapsulated in alginate/chitosan hydrogel particles during storage and simulated gastrointestinal digestion: role of chitosan molecular weight.

Sodium alginate hydrogel particles coated with cationic biopolymers have been shown to be one of the promising means for probiotic encapsulation and protection. In this study, we aimed to systematically explore the effect of molecular weight of chitosan coating on the functional performance of sodium alginate hydrogel particles for improving the viability of Lactobacillus rhamnosus GG (LGG). We first electrostatically deposited three different molecular weights of chitosan coatings, i.e., chitosan oligosaccharide (COS), low molecular weight chitosan (LMW-chitosan) and medium molecular weight chitosan (MMW-chitosan) on sodium alginate hydrogel particles. Both SEM and FTIR results indicated that chitosan was successfully deposited onto the surface of the hydrogel particles. We then evaluated the effect of chitosan MW on the viability of LGG encapsulated in the hydrogels during long-term storage and simulated gastrointestinal digestion. Among them, the hydrogel particles coated with COS prevented the viability loss of LLG during long-term storage at different temperatures (4, 25 and 37 °C). However, we did not find any improvement in the viability of the encapsulated LGG by all three chitosan coatings during simulated digestion.

Occurrence and preventive strategies to control mycotoxins in cereal-based food.

Mycotoxins contamination in cereal-based food is ubiquitous according to systematic review of the scientific documentation of worldwide mycotoxin contamination in cereal and their products between 2008 and 2018, thus representing food safety issue especially in developing tropical countries. Food processing plays a vital role to prevent mycotoxin contamination in food. Therefore, it is with great urgency to develop strategies to inhibit fungi growth and mycotoxin production during food processing. This review begins by discussing physicochemical properties of five most common mycotoxins (aflatoxins, fumonisins, ochratoxins, deoxynivalenol, and zearalenone) found in cereal grains, regulation for mycotoxins in food, and their potential negative impact on human health. The fate of mycotoxins during major cereal-based food processing including milling, breadmaking, extrusion, malting, and brewing was then summarized. In the end, traditional mitigation strategies including physical and chemical and potential application of biocontrol agent and essential oil nanoemulsions that can be applied during food processing were discussed. It indicated that no single method is currently available to completely prevent mycotoxin contamination in cereal foods.

How Do Enzymes Orient When Trapped on Metal-Organic Framework (MOF) Surfaces?

Enzyme immobilization in metal-organic frameworks (MOFs) offers retained enzyme integrity and activity, enhanced stability, and reduced leaching. Trapping enzymes on MOF surfaces would allow for catalysis involving large substrates. In both cases, the catalytic efficiency and selectivity depend not only on enzyme integrity/concentration but also orientation. However, it has been a challenge to determine the orientation of enzymes that are supported on solid matrices, which is even more challenging for enzymes immobilized/trapped in MOFs due to the interferences of the MOF background signals. To address such challenge, we demonstrate in this work the utilization of site-directed spin labeling in combination with Electron Paramagnetic Resonance spectroscopy, which allows for the first time the characterization of the orientation of enzymes trapped on MOF surfaces. The obtained insights are fundamentally important for MOF-based enzyme immobilization design and understanding enzyme orientation once trapped in solid matrices or even cellular confinement conditions.

The Effect of Different Treatments of (-)-Epigallocatechin-3-Gallate on Colorectal Carcinoma Cell Lines.

Backgroud: (-)-Epigallocatechin-3-gallate (EGCG), the major component of green tea, is well documented to induce apoptosis and cell cycle arrest in cancer by targeting multiple signal transduction pathways. However, EGCG is extremely unstable in general culture conditions and rapidly degraded. So, to what extent EGCG or which degradation products of EGCG play a role in anti-tumor is still unknown. In this study, we evaluated the effect of different treatments of EGCG on HCT116 cells. DESIGN: MTT assay was applied to evaluated the inhibitory effect of different treatments of EGCG on HCT116 cells. Cell cycle and apoptosis were performed by flow cytometry. Finally, western blot analysis was used to elucidate the molecular mechanism associated with cell cycle arrest and apoptosis. RESULTS: Compared with control, both EGCG and O-EGCG (i.e., EGCG being pre-incubated at 37°C for 3 h) significantly inhibited HCT116 cells growth. Surprisingly, we found that the inhibitory effect of O-EGCG was stronger than that of EGCG. The IC50 values of EGCG and O-EGCG were 8.75 and 5.40 µM, respectively. Cell cycle analysis showed that 20 µM of EGCG simultaneously caused cell cycle arrest at G1 and G2 phase in HCT116 cells, differing from O-EGCG which exclusively caused cell cycle arrest at G2. This result suggested that parent EGCG at the early treatment might cause cell cycle arrest at G1. As time went on, EGCG disappeared and degraded products of EGCG were formed which might cause cell cycle arrest at G2. Further studies revealed that EGCG induced cell cycle arrest at G1 by downregulation of cyclin E and cyclin D1 and upregulation of p21. On the other hand, O-EGCG induced HCT116 cells apoptosis mainly by increasing the expression of p53 and cleaved caspase-3, which might be the underlying reason why O-EGCG had stronger inhibitory effect on HCT116 cells line than EGCG. CONCLUSIONS: The pretreatment of EGCG may be an effective way to enhance its antitumor effect.

The Inhibition of Advanced Glycation End Products by Carnosine and Other Natural Dipeptides to Reduce Diabetic and Age-Related Complications.

As people age they are at a greater risk for many disorders including cardiovascular, renal, and neurodegenerative diseases, and these conditions are exacerbated by diabetes. An important cause of the maladies associated with both age and diabetes is the formation of advanced glycation end products (AGEs). AGE formation is initiated by glycation reactions between reducing sugars and free amine groups. A cascade of other reactions follows, leading to alterations in membrane function and damage to the proteome, such as protein crosslinking. Compounds that prevent these reactions are currently being researched, but peptides hold great potential as they tend to lack toxicity, are absorbed intact, are easily produced, and are cheaper than other options. Of the peptides researched, carnosine is the most promising. Research suggests that carnosine is absorbed into the plasma unaltered and intact. Carnosine has been shown to prevent AGE formations through reduction of blood glucose, prevention of early glycation, and even reversing previously formed AGEs. Other promising peptides and amino acids include ß-alanine, L-histidine, homocarnosine, anserine, and glutathione. If bioactive peptides and amino acids can minimize the formation of AGEs, foods containing these peptides could be used to improve health.

Plant protein solubility: A challenge or insurmountable obstacle.

Currently, there is an increasing focus on comprehending the solubility of plant-based proteins, driven by the rising demand for animal-free food formulations. The solubility of proteins plays a crucial role in impacting other functional properties of proteins and food processing. Consequently, understanding protein solubility in a deeper sense may allow a better usage of plant proteins. Herein, we discussed the definition of protein solubility from both thermodynamic and colloidal perspectives. A range of factors affecting solubility of plant proteins are generalized, including intrinsic factors (amino acids composition, hydrophobicity), and extrinsic factors (pH, ionic strength, extraction and drying methods). Current methods to enhance solubility are outlined, including microwave, high intensity ultrasound, hydrostatic pressure, glycation, pH-shifting, enzymatic hydrolysis, enzymatic cross-linking, complexation and modulation of amino acids. We base the discussion on diverse modified methods of nitrogen solubility index available to determine and analyze protein solubility followed by addressing how other indigenous components affect the solubility of plant proteins. Some nonproteinaceous constituents in proteins such as carbohydrates and polyphenols may exert positive or negative impact on protein solubility. Appropriate protein extraction and modification methods that meet consumer and manufacturers requirements concerning nutritious and eco-friendly foods with lower cost should be investigated and further explored.

Effect of High-Tunnel and Open-Field Production on the Yield, Cannabinoids, and Volatile Profiles in Industrial Hemp (Cannabis sativa L.) Inflorescence.

This study discovered the impact of high-tunnel (i.e., unheated greenhouse) and open-field production on two industrial hemp cultivars (SB1 and CJ2) over their yield parameters, cannabinoid development, and volatile profiles. Development of neutral cannabinoids (CBD, THC, and CBC), acidic cannabinoids (CBDA, THCA, and CBCA), and total cannabinoids during floral maturation were investigated. The volatile profiles of hemp flowers were holistically compared via HS-SPME-GC/MS. Findings indicated a high tunnel as an efficient practice for achieving greater total weight, stem number, and caliper, especially in the SB1 cultivar. Harvesting high-tunnel-grown SB1 cultivars during early flower maturation could obtain a high CBD yield while complying with THC regulations. Considering the volatile profiles, hemp flowers mainly consisted of mono- and sesquiterpenoids, as well as oxygenated mono- and sesquiterpenoids. Volatile analysis revealed the substantial impact of cultivars on the volatile profile compared to the production systems.

Sensory profile of pulse-based high moisture meat analogs: A study on the complex effect of germination and extrusion processing.

Germination and extrusion are two processes that could affect beany flavors in pulse-based high-moisture meat analogs (HMMAs). This research studied the sensory profile of HMMAs made by protein-rich flours from germinated/ungerminated pea and lentil. Air-classified pulse protein-rich fractions were processed into HMMAs with twin screw extrusion cooking, optimized at 140 °C (zone 5 temperature) and 800 rpm screw speed. Overall, 30 volatile compounds were identified by Gas Chromatography-Mass Spectrometry/Olfactory. Chemometric analysis exhibited that the extrusion markedly (p < 0.05) reduced beany flavor. A synergistic effect of germination and extrusion process was observed, decreasing some beany flavors such as 1-octen-3-ol and 2,4-decadienal, and the overall beany taste. Pea-based HMMAs are suitable for lighter, softer poultry meat, while lentil-based HMMAs are suited for darker, harder livestock meat. Those findings offer novel insights into the regulation of beany flavors, odor notes, color, and taste to improve the sensory quality of HMMAs.

Oleofoams stabilized by monoacylglycerides: Impact of chain length and concentration.

Oleofoams are plant oil based whipped systems which have drawn academic and industry attention in recent years. The aim of this study was to determine the effect of fatty acid chain length and monoacylglyceride (MAG) concentration on the performance and structural properties of MAG-based oleofoams. Four different MAGs (monolaurin, monomyrystin, monopalmitin, and monostearin) were studied at three concentration levels (5, 10, and 15 wt%). The fatty acid chain length had a statistically significant impact on the size and shape of crystals formed, while higher MAG concentrations led to higher numbers of crystals in the continuous oil phase. These differences affected the performance and physical properties of the oleofoams: compared to other MAGs, monostearin based oleofoams were harder and exhibited higher values of G' and G″, had higher overrun and showed better stability. Lastly, through microscopy techniques it was successfully proved that monostearin-based oleofoams are stabilized by both bulk and Pickering stabilization.

Structural, functional properties, and volatile profile of hemp protein isolate as affected by extraction method: Alkaline extraction-isoelectric precipitation vs salt extraction.

The utilization of industrial hemp in food is gaining popularity. This study aimed to comprehensively investigate the impact of alkaline extraction-isoelectric precipitation (AE-IEP) and salt extraction (SE) dialysis on structural, functional properties and the volatile profile of hemp protein isolate (HPI). A higher protein content (97.21%) in SE extracted HPI (SE-HPI) was obtained than the AE-IEP extracted HPI (93.37%). In particular, protein subunit composition, structural properties were strongly influenced by the extraction methods. For example, SE-HPI exhibited a larger percentage of albumin (46.53%) and a lower amount of ß-sheet (52.65%) than its counterpart (albumin 20.92%, ß-sheet 54.46%). Consequently, SE-HPI showed the higher solubility, emulsion activity, and thermal stability. Interestingly, the volatile profile of the proteins showed that SE-HPI exhibited a lower number (21) of volatile compounds when compared to its counterpart (25). This study highlights the importance of establishing the relationships between extraction methods and functional attributes of HPI.

Lysozyme-phenolics bioconjugates with antioxidant and antibacterial bifunctionalities: Structural basis underlying the dual-function.

This work aims at adopting an Electron Paramagnetic Resonance (EPR) spectroscopic technique to help understanding protein-phenolic conjugation and final functionalities relationship as well as the underlying structural basis of antioxidant and antibacterial dual functionalities. Specifically, lysozyme (Lys) was conjugated with two natural phenolic acids, i.e. rosmarinic acid (RA) and gentisic acid (GA, our previous work) with obviously different molecular features. Lys-RA displayed 8.6- and 4.0-times enhanced antioxidant stoichiometry compared to the native Lys and ones with GA, respectively, due to the stronger antioxidant activity of RA. However, RA conjugation mitigated both enzymatic and antibacterial activities of Lys-RA conjugates. Such inhibition effect is attributed to the greater structural and surface property changes of Lys upon conjugating with RA. Furthermore, the polyphenol conjugation related structural basis of disturbance, reactivity and selectivity were explored via site-directed spin labeling (SDSL)-EPR. A dynamic picture of reactivity and selectivity of phenolics conjugation on Lys was proposed.

Antifungal activity, mycotoxin inhibitory efficacy, and mode of action of hop essential oil nanoemulsion against Fusarium graminearum.

This work aims to investigate antifungal, mycotoxin inhibitory efficacy of the hop essential oil (HEO) nanoemulsion and their mode of action (MOA) against Fusarium graminearum isolate, a fungal pathogen causing Fusarium Head Blight (FHB) in cereal crops. The HEO, primarily consisting of terpenes and terpenoids, was encapsulated in nanoemulsion droplets. Physically stable HEO-in-water nanoemulsion was fabricated using 0.5 wt% of tween 80 and 5 wt% oil phase comprising 30 % of Ostwald ripening inhibitor and 70 % of HEO. In terms of antifungal effect, HEO nanoemulsion could not only effectively inhibit mycelial growth and spore germination of F. graminearum isolates, but also remarkably suppress the production of deoxynivalenol (DON) and its derivatives in rice culture by applying 750 µg of HEO/g rice. Our studies on the MOA showed that HEO nanoemulsion could alter the contents of total lipid and chitin in outer cell membrane as well as damaging cytoplasmic membrane.

Molecular interaction mechanism and structure-activity relationships of protein-polyphenol complexes revealed by side-directed spin labeling-electron paramagnetic resonance (SDSL-EPR) spectroscopy.

Deciphering interactions between bioactive protein and polyphenols are critical for designing and controlling functional protein-polyphenol complexes. Herein, using the site-directed spin labeled T4 lysozyme (T4L) and rosmarinic acid (RA) as a model system, we combined electron paramagnetic resonance spectra to investigate molecular interaction mechanism of the protein-polyphenol complexes in structural or conformational details. Experimental results show that molecular interactions between T4L and RA are a process from order to disorder. TEM images display that the complexes finally assemble into quasi-spherical colloidal particles. When T4L/RA ratio is 1:1, the complexes exhibit the optimized enzymatic and antioxidant dual-functionalities due to the synergetic effect and protection mechanism. However, with excess addition of RA, the enzymatic and antioxidant activities of the complexes started to attenuate because the catalytic active site and bioactive hydroxyl groups were buried. The revealed high-resolution interaction process could help better understand the corresponding alterations between structure and functionalities.

Unraveling the role of germination days on the aroma variations of roasted barley malts via gas chromatography-mass spectrometry based untargeted and targeted flavoromics.

Roasting imparts malts with an increased amount of hedonic aromas. However, the relationship between the production of roasted malts and the generation of characteristic malt aromas remains unclear. In this study, roasted barley malts (RM) were prepared from three consecutive germination days (3, 4, 5D), and the aroma profiles among RM and base malt were holistically compared via HS-SPME-GC-MS/O-based flavoromics. Furthermore, the wort color, free amino acids, reducing sugars, and fatty acids compositions were determined before-and-after roasting. Results showed that roasting could flatten variations of precursors regardless of germination days. Additionally, based on quantitation of 53 aromas, a PLS-DA model was applied to differentiate all malts by 17 aromas with VIP ≥ 1. As for aroma harmony, RM with 4D-germination outstood due to a pleasant nutty note with the highest sweet-to-nutty index of 0.8. This work answers how germination days would impact the aroma of RM for the first time.