Effect of Novel Processing Techniques on the Carotenoid Release during the Production of Red Guava Juice.

Red guava, distinguished by its elevated lycopene content, emerges as a promising natural source of carotenoids. This study systematically evaluates the impact of diverse processing techniques on the efficient release of carotenoids. The primary objective is to facilitate the transfer of carotenoids into the juice fraction, yielding carotenoid-enriched juice seamlessly integrable into aqueous-based food matrices. The untreated guava puree exhibited a modest release of carotenoids, with only 66.26% of ß-carotene and 57.08% of lycopene reaching the juice. Contrastly, both high-pressure homogenization (HPH) at 25 MPa and enzyme (EM) treatment significantly enhanced carotenoid release efficiency (p < 0.05), while high hydrostatic pressure (HHP) at 400 MPa and pulsed electric field (PEF) of 4 kV/cm did not (p > 0.05). Notably, HPH demonstrated the most substantial release effect, with ß-carotene and lycopene reaching 90.78% and 73.85%, respectively. However, the stability of EM-treated samples was relatively poor, evident in a zeta-potential value of -6.51 mV observed in the juice. Correlation analysis highlighted the interactions between pectin and carotenoids likely a key factor influencing the stable dissolution or dispersion of carotenoids in the aqueous phase. The findings underscore HPH as a potent tool for obtaining carotenoid-enriched guava juice, positioning it as a desirable ingredient for clean-label foods.

Enhancing activity of food protein-derived peptides: An overview of pretreatment, preparation, and modification methods.

Food protein-derived peptides have garnered considerable attention due to their potential bioactivities and functional properties. However, the limited activity poses a challenge in effective utilization aspects. To overcome this hurdle, various methods have been explored to enhance the activity of these peptides. This comprehensive review offers an extensive overview of pretreatment, preparation methods, and modification strategies employed to augment the activity of food protein-derived peptides. Additionally, it encompasses a discussion on the current status and future prospects of bioactive peptide applications. The review also addresses the standardization of mass production processes and safety considerations for bioactive peptides while examining the future challenges and opportunities associated with these compounds. This comprehensive review serves as a valuable guide for researchers in the food industry, offering insights and recommendations to optimize the production process of bioactive peptides.

Composition, processing, and quality control of whole flaxseed products used to fortify foods.

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid-amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.

Oligomeric Procyanidin Nanoliposomes Prevent Melanogenesis and UV Radiation-Induced Skin Epithelial Cell (HFF-1) Damage.

The potential protective effect of nanoliposomes loaded with lotus seedpod oligomeric procyanidin (LSOPC) against melanogenesis and skin damaging was investigated. Fluorescence spectroscopy showed that, after encapsulation, the LSOPC-nanoliposomes still possessed strong inhibitory effects against melanogenesis, reducing the activity of both monophenolase and diphenolase. Molecular docking indicated that LSOPC could generate intense interactive configuration with tyrosinase through arene-H, arene-arene, and hydrophobic interaction. An ultraviolet radiated cell-culture model (human foreskin fibroblast cell (HFF-1)) was used to determine the protective effects of the LSOPC-nanoliposomes against skin aging and damage. Results showed that LSOPC-nanoliposomes exerted the highest protective effects against both ultraviolet B (UVB) and ultraviolet A (UVA) irradiation groups compared with non-encapsulated LSOPC and a control (vitamin C). Superoxide dismutase (SOD) and malonaldehyde (MDA) assays demonstrated the protection mechanism may be related to the anti-photooxidation activity of the procyanidin. Furthermore, a hydroxyproline assay suggested that the LSOPC-nanoliposomes had a strong protective effect against collagen degradation and/or synthesis after UVA irradiation.

Potential TSPO Ligand and Photooxidation Quencher Isorenieratene from Arctic Ocean Rhodococcus sp. B7740.

Due to its special aromatic structure, isorenieratene is thought to be an active natural antioxidant and photo/UV damage inhibitor. In this work, isorenieratene that was extracted from Rhodococcus sp. B7740 isolated from the Arctic Ocean, showed excellent scavenging ability of both singlet oxygen and hydroxyl radical in the UVB-induced auto-oxidation process using the EPR method. Within an ARPE-19 cell model damaged by UVB radiation, isorenieratene showed fine protective effects (1.13 ± 0.03 fold) compared with macular xanthophylls (MXs) through upregulating of tspo. The molecular docking was firstly performed to investigate the interaction of isorenieratene with TSPO as a special ligand. Results showed isorenieratene might form a better binding conformation (S-score -8.5438) than MXs and indicate that isorenieratene not only can function as a direct antioxidant but also activate tspo in ARPE-19 cells. Thus, isorenieratene might ease the UV-related damages including age-related macular degeneration (AMD).

Characterization of MK8(H2) from Rhodococcus sp. B7740 and Its Potential Antiglycation Capacity Measurements.

Menaquinone (MK) has an important role in human metabolism as an essential vitamin (VK2), which is mainly produced through the fermentation of microorganisms. MK8(H2) was identified to be the main menaquinone from Rhodococcus sp. B7740, a bacterium isolated from the arctic ocean. In this work, MK8(H2) (purity: 99.75%) was collected through a convenient and economic extraction process followed by high-speed countercurrent chromatography (HSCCC) purification. Additionally, high-resolution mass spectrometry (HRMS) was performed for further identification and the hydrogenation position of MK8(H2) (terminal unit) was determined using nuclear magnetic resonance (NMR) for the first time. MK8(H2) showed a superior antioxidant effect and antiglycation capacity compared with ubiquinone Q10 and MK4. High-performance liquid chromatography⁻mass spectrometer (HPLC-MS/MS) and molecular docking showed the fine interaction between MK8(H2) with methylglyoxal (MGO) and bull serum albumin (BSA), respectively. These properties make MK8(H2) a promising natural active ingredient with future food and medicine applications.

Insight into the Influence of Lactic Acid Bacteria Fermentation on the Variations in Flavor of Chickpea Milk.

This study aimed to evaluate the influence of fermentation on the levels of free amino acids (FAAs) and variations of volatile odorants in four groups of chickpea milk. Electronic nose (E-nose) and gas chromatography-mass spectrometry (GC-MS) data were subjected to mutual validation. W2S and W3S sensors of E-nose were sensitive to volatile constituents in the four groups of unfermented and fermented specimens. After fermentation, the levels of FAAs in the four groups of specimens decreased to varying degrees. Additionally, there were remarkable differences in the types and contents of volatile odor substances in all specimens before and after fermentation. The principal component analysis findings based on E-nose identified the changes of volatile odorants in all specimens before and after fermentation. GC-MS identified 35 and 55 volatile flavor substances in unfermented and fermented specimens, respectively. The varieties of volatile odor substances in fermented chickpea milk (FCM) with papain treatment plus yam addition (38) were more than those in FCM (24), indicating that the coupled treatment of enzymolysis and yam addition could enrich the volatile odorants in fermented specimens. After probiotic fermentation, the contents of off-flavor substances decreased to a certain extent, and key aroma substances such as 2,3-pentanedione, 2,3-butanedione, and heptyl formate were detected. These results demonstrated that lactic acid bacterial fermentation on the basis of enzymolysis and yam addition could be utilized as a feasible approach to improve the flavor of plant-based products adopting chickpea as the original ingredient.

Determination of 14 Isoflavone Isomers in Natto by UPLC-ESI-MS/MS and Antioxidation and Antiglycation Profiles.

Natto is a famous traditional fermented food, but the influence of the fermentation process on the content and composition of soybean isoflavones and nutritional value is still unclear. In the present study, the variation in soybean isoflavones during fermentation by Bacillus subtilis natto was revealed by UPLC-ESI-MS/MS (Ultra high performance liquid chromatography-electron spray ionization-mass spectrometry) analysis. After 24 h of fermentation, the total isoflavone content in natto increased by 1.62 times compared with fresh soybean, and the content of aglycones was 3.07 times that of raw beans. More importantly, among 14 isoflavone isomers identified in natto, the isomers of daidzin, genistin, and succinyl genistin were detected for the first time, which might be due to the result of isomerase and succinylase and other corresponding enzymes' action in Bacillus subtilis. In addition, natto isoflavones performed great antioxidant activity than its monomer components (glycosides daidzin and genistin, aglycones genistein and daidzein), except for genistein. Moreover, natto isoflavone and its aglycones (especially genistein) performed great inhibitory activity against AGEs (Advanced Glycation End Products) in three in vitro models. The mechanism test showed that genistein could form adducts (UPLC-Q-TOF-ESI-MS/MS analysis) with methylglyoxal. These findings demonstrated that soybean fermented with Bacillus subtilis natto had a significant influence on the isoflavone profiles and its bioactivity.

Molecular mechanism of epicatechin gallate binding with carboxymethyl ß-glucan and its effect on antibacterial activity.

The non-covalent binding between flavanols and polysaccharides has impacts on their bioactivities, but the binding mechanism is less understood. This work aimed to unveil the non-covalent interactions between epicatechin gallate (ECG) and anionic carboxymethyl Poria cocos polysaccharide (CMPN) at the structural and molecular level based on the synergistic antibacterial effect between them. The results suggested that there was hydrogen bonding, hydrophobic and electrostatic interaction between ECG and CMPN, which was also supported by the results of molecular dynamics simulations. The resulting changes in physicochemical properties enhanced the antibacterial activity of the ECG-CMPN mixture. More specifically, through two-dimensional Fourier transform infrared correlation spectrum (2D-FT-IR) and nuclear magnetic resonance spectroscopy (NMR) analysis, COO- in CMPN carboxymethyl and CO in ECG galloyl had the highest response priority and binding strength in the interaction, allowing us to conclude the critical functional groups that affect the non-covalent interactions of polysaccharide and flavanols and their bioactivities.

Anion carboxymethylated ß-glucan alleviates undesirable binding between procyanidins and ß-galactosidase.

To solve the potential problem of hindered ß-galactosidase activity by procyanidins, carboxymethylated Pachyman (CMP), a negatively-charged carboxymethylated (1 â†’ 3)-ß-d-glucan, was applied to mitigate inhibition by procyanidins. The mechanisms underlying this effect were explored through enzyme kinetic analysis, fluorescence quenching assays, circular dichroism, and molecular docking studies. The results indicated that the introduction of CMP could decrease the inhibition rate of high-concentration lotus seedpod oligomeric procyanidins (LSOPC) from 98.7 to 46.5%, and enabled low-concentration LSOPC to activate ß-galactosidase in vitro and in vivo. The competitive/noncompetitive inhibition constants, fluorescence quenching constants, and molecular docking results indicated that the mechanism of this effect might be CMP competing with ß-galactosidase to bind procyanidins, resulting in restoration of the catalytic centre and key active site of procyanidin-bound lactase. Additionally, it was affected by procyanidin-CMP noncovalent interactions. This study illustrates a promising strategy for mitigating the anti-nutritional properties of procyanidins and activating ß-galactosidase to promote intestinal health.

Diabetes diminishes a typical metabolite of litchi pericarp oligomeric procyanidins (LPOPC) in urine mediated by imbalanced gut microbiota.

Animal studies and clinical trials have shown that dietary polyphenols and polyphenol-rich foods can reduce the risk of type 2 diabetes (T2D) and its complications, but how diabetes regulates the metabolism of polyphenol has not been fully elucidated. This study investigated the effects of diabetes on litchi pericarp oligomeric procyanidin (LPOPC) dynamic metabolism and its major static metabolites in urine. First, a high-fat and streptozotocin (STZ)-induced diabetic Sprague Dawley (SD) rat model was established. In the diabetic rat model, elevated fasting blood glucose, severely impaired glucose tolerance test, and increased reactive oxygen species (ROS) levels in serum and the liver were observed. Subsequently, 200 mg per kg body weight of LPOPC was administrated to control and diabetic SD rats, and the gastrointestinal tract was collected at 0.5 h, 1 h, 3 h, and 6 h. The results showed that the retention time of LPOPC was not changed in our diabetic rat model. However, the gut microbiota were significantly altered, with elevated Proteobacteria and Verrucomicrobia abundance in diabetic rats and decreased short chain fatty acid (SCFA)-producing bacteria. Interestingly, after one dose of 300 mg per kg body weight LPOPC, the total antioxidant capacity of urine in diabetic rats significantly decreased. We then tested the static metabolites of LPOPC, demonstrating that epicatechin had not changed in urine in diabetic rats, but that shikimic acid was significantly reduced in urine in diabetic rats. The changes in shikimic acid may be due to the alteration of gut microbiota and elevated ROS levels in serum.

Fabrication and characterization of whey protein isolates- lotus seedpod proanthocyanin conjugate: Its potential application in oxidizable emulsions.

Emulsified ω-3 polyunsaturated fatty acid have expanding application in different food matrix with improved water solubility while still prone to oxidation. Lotus seedpod proanthocyanidin (LSPC) was grafted to whey protein isolate (WPI) to create nature-derived antioxidant emulsifiers. 1HNMR, SDS-PAGE and multiple spectrometry showed that the structure of protein was changed after grafting. DPPH and FRAP measurements showed that WPI-LSPC conjugate (90.53 ± 1.48% of DPPH scavenging, 691.85 ± 4.54 µg/mL for FRAP assay) possessed a much better antioxidant ability than WPI (17.06 ± 3.34% of DPPH scavenging, 10.43 ± 0.26 µg/mL for FRAP assay). Ultrasonic emulsification and DSC experiments showed that WPI-LSPC conjugate were more effective at forming and stabilizing the flaxseed oil emulsions than pure WPI, with higher thermostability. Likewise, low levels of primary and secondary oxidation products were formed for the conjugate than the pure protein in O/W systems after storage, again suggesting WPI-LSPC could be used as fine antioxidant emulsifiers in oxidizing delivery systems.

Metabolites of Procyanidins From Litchi Chinensis Pericarp With Xanthine Oxidase Inhibitory Effect and Antioxidant Activity.

Procyanidins from litchi pericarp (LPPC) has been evidenced to possess strong antioxidant activities in vivo that is possibly correlated with their intestinal metabolites. However, the xanthine oxidase inhibitory effect of LPPC and its metabolites was less concerned. In this study, three oligomeric procyanidins and eight metabolic phenolic acids were identified in the urine of rats administrated with LPPC by high performance liquid chromatography and liquid chromatography-mass spectrometry analysis. Data indicated that all the metabolites excreted were significantly increased by the treatment of 300 mg/kg body weight of LPPC (P < 0.05), revealing considerable 1, 1-Diphenyl-2-Picrylhydrazyl (DPPH) and hydroxyl radicals activities of scavenging. Moreover, phenolic metabolites involving epicatechin, A-type dimer, A-type trimer, caffeic acid, and shikimic acid exhibited greater xanthine oxidase inhibition effects compared with other metabolites, with an inhibitory rate higher than 50% at the concentration 200 µg/ml. The IC50 value of these five phenols were 58.43 ± 1.86, 68.37 ± 3.50, 74.87 ± 1.30, 95.67 ± 3.82, and 96.17 ± 1.64 µg/ml, respectively. As a whole, this work suggests that the xanthine oxidase inhibition and antioxidant activity of LPPC-derived metabolites as one of the mechanisms involved in the beneficial effects of LPPC against hyperuricemia or gout.

Effect of ultrasound combined with ultraviolet treatment on microbial inactivation and quality properties of mango juice.

This work explored the effect of ultraviolet-assisted ultrasound (US-UV) as an emerging non-thermal sterilization technology on mango juice in aspects of microbial growth and quality changes. The juice in the ice bath was subjected to US-UV treatment at different US powers (0-600 W) and times (0-40 min), and no pathogen bacteria could be detected after treatment, while the physicochemical features (particle size, suspension stability, color, content of total polyphenols, carotenoids, sugar, reducing sugar and protein) and antioxidant ability of treated juice was preserved or improved to some extent. Based on these results, we further validated its positive effects on the nutritional value (content of ascorbic acid and soluble dietary fiber, antioxidant ability) and quality parameters (titratable acid, sugar acidity, total soluble solids, rheological behavior, metal elements) of mango juice treated at the optimal US parameter (10 min, 600 W); Not only the inactivation of polyphenol oxidation enzyme, peroxidase and pectin methylesterase was achieved but also the treated juice has a significant different volatile profile compared with the fresh juice, which might offer the better color, texture, and smell. Importantly, through the HPLC-MSD-Trap-XCT (phenols) and UPLC-Q Exactive Orbitrap-MS (carotenoids) study, the US-UV treatment will not cause difference on compounds composition, but it was responsible for changes in content of individual compounds, especially the all-trans-ß-carotene, became the main component of carotenoids in processed mango juice (increased from 43.72% to 75.15%, relative content), and the oxygenated carotenoids (xanthophylls) are highly sensitive to the US (reduced from 50.96% to 4.85%) while the carotenes show a strong resistance to the US (increased 49.04% to 95.15%). Thus, the overall safety and quality of mango juice were enhanced while the sensory characteristics remained stable, suggesting that this non-thermal combination sterilization processing may successfully be implemented in the commercial processing of mango juice.

Lotus seedpod proanthocyanidin-whey protein complexes: Impact on physical and chemical stability of ß-carotene-nanoemulsions.

The impact of lotus seedpod proanthocyanidin (LSPC) on the functional properties of ß-carotene-loaded whey-protein stabilized nanoemulsions was investigated. LSPC was selected because it is known to exhibit strong antioxidant activity, as well as having various health benefits. Physically stable nanoemulsions containing small anionic droplets (d < 0.15 µm; ζ = -27 mV) could be formed at pH 6.5 using whey protein-LSPC complexes as natural emulsifiers. The physical and chemical stabilities of the nanoemulsions were then measured when they were incubated at different pH values. LSPC addition promoted droplet aggregation at pH 4, but not at pH 3, 6.5, or 8, which was mainly attributed to its ability to reduce the electrostatic repulsion between the lipid droplets at pH 4. LSPC was shown to have stronger antioxidant activity than catechin and epicatechin. Our results show that the chemical stability of ß-carotene nanoemulsions could be considerably improved by adding LSPC. We believe that LSPC-whey protein complexes can be used as effective emulsifiers and antioxidants in nutraceutical-loaded nanoemulsions, which may be useful for developing more efficacious functional foods and beverages.

Flavonoid compounds and antibacterial mechanisms of different parts of white guava (Psidium guajava L. cv. Pearl).

The flavonoid compositions, extracted from leaves, peel and flesh of white guava (Psidium guajava L. cv. Pearl), were identified and quantified by UPLC-ESI-QTOF-MS, HPLC-ESI-MS/MS and HPLC. The main components of three extracts all were quercetin-glycosides, but the proportion and content of quercetin-hexoside and quercetin-pentoside in each extract were different. Based on the measurements of MIC, MBC value and time killing curve, it emerged that 3 flavonoid extracts of white guava had good antibacterial effects on four pathogenic bacteria. White guava leaves flavonoids (WGLF) concentrations of 5.00 mg/mL and 0.625 mg/mL could change the micro-morphology of Escherichia coli and Staphylococcus aureus. It suggested that the antibacterial mechanism of WGLF on gram-positive and gram-negative bacteria was to destroy the structure and function of the cell membrane. It is indicated that the flavonoid extracts from white guava is a potential natural antimicrobial agent.

Impact Toughness Anisotropy of TA31 Titanium Alloy Cylindrical Shell after Ring Rolling.

The impact toughness of a TA31 titanium alloy cylindrical shell was investigated systemically after ring rolling. The impact toughness of specimens with different notch orientations shows obvious anisotropy. The microstructure of the cylindrical shell and the impact fracture were characterized by an optical microscope and scanning electron microscope. The results show that cracks are easier to propagate in the equiaxed α phase than the elongated α phase. This is because the expanding cracking path in the equiaxed α phase is shorter than that in the elongated α phase, and thereby the cracks are easier to propagate in the equiaxed α phase than the elongated α phase. More specifically, the α phase on the RD-TD plane was obviously isotropic, which makes it easy for the cracks to propagate along α grains in the same direction. However, the α phase on the RD-ND plane has a layered characteristic, and the direction of the α phase varies from layer to layer, thus it requires higher energy for cracks to propagate across this layered α phase. Therefore, the cracks propagating in the same α phase orientation take easier than that in the layered α phase, so it has lower impact toughness.

Procyanidins extracted from the lotus seedpod ameliorate scopolamine-induced memory impairment in mice.

The major purpose of this study was to determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the learning and memory impairments induced by scopolamine (1 mg/kg, i.p.) in mice. The capacities of memory and learning were evaluated by the Morris water maze and the step-down avoidance test. LSPC (50, 100, 150 mg/kg BW, p.o.) significantly reversed scopolamine-induced learning and memory impairments in the Morris water maze test, as evaluated by shortened escape latency and swimming distance. In the step-down avoidance test, LSPC (50, 100, 150 mg/kg BW, p.o.) treatment significantly reduced the number of errors and shortened latency compared with that of scopolamine. In addition, LSPC was also found to inhibit acetyl cholinesterase (AChE) activity. These results of this study suggest that LSPC may play a useful role in the treatment of cognitive impairment caused by AD and aging.

Interaction between carboxymethyl pachyman and lotus seedpod oligomeric procyanidins with superior synergistic antibacterial activity.

The inhibitory effect of carboxymethyl pachyman (CMP) mixed with lotus seedpod oligomeric procyanidins (LSPC) in certain ratios against E. coli 10899 was determined. Added low concentration of LSPC could improve the antibacterial activity of CMP, and a significant synergistic effect could be observed between them, especially when the concentration of CMP was below its critical concentration (1.35 mg/mL). Then, the interaction between CMP and LSPC was characterized after mixing; the changes in spectral characteristics, thermal properties, crystallinity pattern, molecular weight, chain morphology and microrheological behaviour explained the influence of interaction on the structure of CMP and LSPC. The smaller molecular size, electrostatic interaction and stronger hydrophobic interaction might play important roles in improving the antibacterial activity of mixture. The dissociation constant (Kd) was determined to be 0.102±0.0008 mg/mL using MicroScale Thermophoresis (MST), and the micromorphology was observed by SEM. Therefore, this mixture might be an effective natural bacteriostat.

Effect of Thermo-Sonication and Ultra-High Pressure on the Quality and Phenolic Profile of Mango Juice.

Consumer demand for safe and nutritious fruit juices has led to the development of a number of food processing techniques. To compare the effect of two processing technologies, thermo-sonication (TS) and ultra-high pressure (UHP), on the quality of mango juice, fresh mango juice was treated with TS at 25, 45, 65 and 95 °C for 10 min and UHP at 400 MPa for 10 min. The phenolic profile of mango was also analyzed using the newly developed ultra-performance liquid chromatography-electrospray ionization-quadrupole time of flight-mass spectrometry (UPLC-Q-TOF-HRMSn) and, based on this result, the effect of TS and UHP on the phenolics of mango juice was evaluated. Both treatments had minimal effects on the oBrix, pH, and titratable acidity of mango juice. The residual activities of three enzymes (polyphenol oxidase, peroxidase, and pectin methylesterase), antioxidant compounds (vitamin C, Total phenolics, mangiferin derivatives, gallotannins, and quercetin derivatives) and antioxidant activity sharply decreased with the increase in the temperature of the TS treatment. Nevertheless, the UHP treatment retained antioxidants and antioxidant activity at a high level. The UHP process is likely superior to TS in bioactive compounds and antioxidant activity preservation. Therefore, the mango juice products obtained by ultra-high-pressure processing might be more beneficial to health.