Research on Extraction Technologies, Analysis Methods and Functional Evaluation of Food Active Components

Distillers’ grains are rich in protein and constitute a high-quality source of various bioactive peptides. The purpose of this study is to identify novel bioactive peptides with α-glucosidase inhibitory, antioxidant, and insulin resistance-ameliorating effects from distiller’s grains protein hydrolysate. Three novel peptides (YPLPR, AFEPLR, and NDPF) showed good potential bioactivities, and the YPLPR peptide had the strongest bioactivities, whose IC₅₀ values towards α-glucosidase inhibition, radical scavenging rates of 2,2′-azino-bis (3-ethylbenzothiazoline-6- sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were about 5.31 mmol/L, 6.05 mmol/L, and 7.94 mmol/L, respectively. The glucose consumption of HepG2 cells treated with YPLPR increased significantly under insulin resistance condition. Moreover, the YPLPR peptide also had a good scavenging effect on intracellular reactive oxygen species (ROS) induced by H₂O₂ (the relative contents: 102.35% vs. 100%). Molecular docking results showed that these peptides could stably combine with α-glucosidase, ABTS, and DPPH free radicals, as well as related targets of the insulin signaling pathway through hydrogen bonding and van der Waals forces. This research presents a potentially valuable natural resource for reducing oxidative stress damage and regulating blood glucose in diabetes, thereby increasing the usage of distillers’ grains peptides and boosting their economic worth. Full article

Sanghuangporus sanghuang is a rare fungus growing on mulberry trees that has immense medicinal value. This study aimed to optimize the liquid-fermentation-media formulation and culture conditions for large-scale culturing of S. sanghuang by performing one-way testing and response surface methodology. The antioxidant and anticancer activities of the extracellular polysaccharides from S. sanghuang were also analyzed. The optimal formulation and growth conditions for S. sanghuang were as follows: glucose, 30.2 ± 0.37 g/L; yeast extract, 14.60 ± 0.05 g/L; dandelion powder, 1.24 ± 0.01 g/L; shaker speed, 150 r/min; and temperature, 25 °C. We obtained 13.99 ± 0.42 g/L of mycelium biomass by culturing S. sanghuang for 15 days with the optimized formulation. This was 2-fold higher than the mycelial mass obtained with the sub-optimal formulation. The extracellular fungal polysaccharides showed significant antioxidant activity against ABTS and DPPH free radicals, and significantly reduced the in vitro growth and survival of several cancer cell lines. The anticancer activity of the extracellular fungal polysaccharides was significantly higher in the human glioma cells than in other cancer cell lines. In summary, this study optimized the liquid media formulation and conditions for the large-scale culturing of S. sanghuang. Furthermore, the extracellular polysaccharides from S. sanghuang showed significant antioxidant and anticancer activities. Full article

This study aimed to investigate the synergistic effects of high-intensity ultrasound (0, 5, 10, 15, and 20 min) in combination with L-lysine (15 mM) on improving the solubility and flavour adsorption capacity of myofibrillar proteins (MPs) in low-ion-strength media. The results revealed that the ultrasound treatment for 20 min or the addition of L-lysine (15 mM) significantly improved protein solubility (p < 0.05), with L-lysine (15 mM) showing a more pronounced effect (p < 0.05). The combination of ultrasound treatment and L-lysine further increased solubility, and the MPs treated with ultrasound at 20 min exhibited the best dispersion stability in water, which corresponded to the lowest turbidity, highest absolute zeta potential value, and thermal stability (p < 0.05). Based on the reactive and total sulfhydryl contents, Fourier transform infrared spectroscopy, and fluorescence spectroscopy analysis, the ultrasound treatment combined with L-lysine (15 mM) promoted the unfolding and depolymerization of MPs, resulting in a larger exposure of SH groups on the surface, aromatic amino acids in a polar environment, and a transition of protein conformation from α-helix to β-turn. Moreover, the combined treatment also increased the hydrophobic bonding sites, hydrogen-bonding sites, and electrostatic effects, thereby enhancing the adsorption capacity of MPs to bind kenone compounds. The findings from this study provide a theoretical basis for the production and flavour improvement of low-salt MP beverages and the utilisation of meat protein. Full article

Jujube residue is an abundant and low-cost dietary fiber resource, but its relatively lower hydration and functional properties limit its utilization as an ingredient of functional food. Thus, cellulase and hemicellulase hydrolysis, enzymatic hydrolysis assisted by phosphate grafting (EPG), and enzymatic hydrolysis assisted by acrylate grafting (EAG) were used to improve the functional properties of jujube residue dietary fiber (JRDF) in this study. The results evidenced that these modifications all increased the porosity of the microstructure of JRDF and increased the soluble fiber content, surface area, and hydration properties, but reduced its brightness (p < 0.05). Moreover, JRDF modified by enzymolysis combined with acrylate grafting offered the highest extractable polyphenol content, oil, sodium cholate, and nitrite ion sorption abilities. Meanwhile, JRDF modified via enzymolysis assisted by phosphate grafting showed the highest soluble fiber content (23.53 g∙100 g⁻¹), water-retention ability (12.84 g∙g⁻¹), viscosity (9.37 cP), water-swelling volume (10.80 mL∙g⁻¹), and sorption ability of copper (II) and lead (II) ions. Alternatively, JRDF modified with cellulase hydrolysis alone exhibited the highest glucose adsorption capacity (21.9 g∙100 g⁻¹) at pH 7.0. These results indicate that EPG is an effective way to improve the hypolipidemic effects of JRDF, while EAG is a good choice to enhance its hydration and hypoglycemic properties. Full article

This paper investigated the antibacterial mechanism of spermidine-capped carbon dots (S-PCDs) against Staphylococcus aureus. The results showed that there were a large number of amino groups on the surface of S-PCDs and they had a high positive charge (+47.06 mV), which could be adsorbed on the negatively charged bacterial surface through electrostatic interaction and changed the permeability of the bacterial cell membrane. The extracellular protein and nucleic acid contents of S. aureus treated with S-PCDs were 5.4 and 1.2 times higher than those of the control group, respectively. The surface folds and defects of the bacterial cell membrane, and the leakage of cell contents were observed using SEM and TEM. The expression of metabolic oxidation regulatory genes dmpI, narJ and narK was upregulated and the intracellular ROS generation was induced, causing bacterial oxidative stress and eventually bacterial death. S-PCDs can effectively inhibit biofilm formation and had low cytotoxicity. The S-PCD treatment successfully inhibited microbial reproduction when pasteurized milk was stored at 25 °C and 4 °C. These results provide important insights into the antimicrobial mechanism of S-PCDs and lay the foundation for their application in the food field as a potentially novel bacteriostatic nanomaterial. Full article

Ginger is an herbaceous and flowering plant renowned for its rhizome, which is widely employed as both a spice and an herb. Since ancient times, ginger has been consumed in folk medicine and traditional cuisines for its favorable health effects. Different in vitro and in vivo studies have disclosed the advantageous physiological aspects of ginger, primarily due to its antioxidant, anti-inflammatory, antimicrobial, and anti-carcinogenic properties. These health-promoting features are linked to the variety of bioactive compounds that are present in ginger. Following the advancement in consumer awareness and the industrial demand for organic antioxidants and functional ingredients, the application of ginger and its derivatives has been broadly investigated in a wide range of food products. The prominent features transmitted by ginger into different food areas are antioxidant and nutraceutical values (bakery); flavor, acceptability, and techno-functional characteristics (dairy); hedonic and antimicrobial properties (beverages); oxidative stability, tenderization, and sensorial attributes (meat); and shelf life and sensorial properties (film, coating, and packaging). This review is focused on providing a comprehensive overview of the tendencies in the application of ginger and its derivatives in the food industry and concurrently briefly discusses the beneficial aspects and processing of ginger. Full article

Evidence from the scientific community suggests that high levels of added sugar consumption contribute to the global epidemics of glucose intolerance, diabetes, and cardiovascular disease. The study aims to develop a local traditional food product (Kleicha) with healthy ingredients and to take advantage of the most productive crops in Saudi Arabia, namely dates, where Khalas date powder and molasses will be manufactured as an alternative to sugar in the Kleicha product. Six Kleicha samples with different fillings were manufactured as follows: Kleicha filled with sugar filling (KS), Kleicha with Khalas date powder filling (KD), Kleicha filled with Khalas date molasses filling (KM), Kleicha filled with sugar and Khalas date powder (1:1) filling (KSD), Kleicha filled with sugar and Khalas date molasses (1:1) filling (KSM), and Kleicha filled with Khalas date powder and Khalas date molasses (1:1) filling (KDM). In order to evaluate the prepared Kleicha samples, the proximate chemical composition, mineral content, phytochemical content and their antioxidant activities, sugar profiles using HPLC, in vitro glycemic index, glycemic load, and sensory evaluation were investigated. The results indicated that KM had the highest moisture content, while the KS sample had the lowest content. KD and KM had significantly higher ash contents compared with the other Kleicha samples. The protein and fat contents did not differ significantly. KD, KSD, and KDM demonstrated a significantly higher dietary fiber content than the other Kleicha samples. KS had the highest value of available carbohydrates. Regarding mineral content, the KDM sample had the highest K, Na, Ca, and P contents, while KD and KM had the highest Mg, Fe, and Mn contents. The Cu content indicated that KM had the highest content, representing a 25% increase compared with KS. Similarly, the Zn content in KM and KSD was significantly higher than in the other Kleicha samples. Replacing sucrose with Khalas date or molasses significantly changed the sucrose, glucose, and fructose contents. The phenolic content in KD, KM, and KDM was higher compared with KS, KSM, and KSD. Furthermore, the oxidative activity increased associatively with the addition of Khalas date powder and molasses. The percentage of sucrose decreased in KD and KDM. There was no significant difference in the general acceptance rate between the control sample and the other samples containing Khalas date powder, Khalas date molasses, and sugar or their mixture. In conclusion, it is possible to replace the sugar in the filling of the Kleicha with Khalas date powder and molasses or their mixture as it increases the health benefits; scaling up is recommended. Full article

Volatile constituents are critical to the flavor of tea, but their changes in raw Pu-erh tea (RAPT) during storage have not been clearly understood. This work aimed to investigate the volatile composition and their changes at various storage durations. The volatile profile of RAPT was determined using headspace solid-phase microextraction in combination gas chromatography–mass spectrometry. A total of 130 volatile compounds were identified in RAPT samples, and 64 of them were shared by all samples. The aroma attributes of RAPT over a storage period ranging from 0 to 10 years were assessed through the combination of odor activity value (OAV), aroma characteristic influence(ACI) value, and multivariate statistical analysis. The results revealed that RAPT exhibited a distinct floral and fruity aroma profile after storage for approximately 3–4 years. A notable shift in aroma was observed after 3–4 years of storage, indicating a significant turning point. Furthermore, the likely notable shift after 10 years of storage may signify the second turning point. According to the odor activity value (OAV ≥ 100), eight key volatile compounds were identified: linalool, α-terpineol, geraniol, trans-β-ionone, α-ionone, (E,E)-2,4-heptadienal, 1-octanol, and octanal. Combining OAV (≥100) and ACI (≥1), five compounds, namely linalool, (E,E)-2,4-heptadienal, (Z)-3-hexen-1-ol, 2,6,10,10-tetramethyl-1-oxaspiro [4.5]dec-6-ene, and octanal, were identified as significant contributors to the aroma. The results offer a scientific foundation and valuable insights for understanding the volatile composition of RAPT and their changes during storage. Full article

Undecapeptide is the central peptide molecule in the peptide base material of Stropharia rugosoannulata, and angiotensin-converting enzyme (ACE) plays a crucial role in hypertension. To fully explore the interaction mechanism and ACE-inhibitory activity of long-chain peptides from Stropharia rugosoannulata, the binding conformations of twenty-seven undecapeptides with the ACE receptor were revealed by molecule docking. The undecapeptide GQEDYDRLRPL with better receptor binding capacity and higher secondary mass spectral abundance was screened. All amino acid residues except proline in GQEDYDRLRPL interacted with the ACE receptor. GQEDYDRLRPL interfered with the receptor’s overall structure, with significant fluctuations in amino acid residues 340–355, including two residues in the receptor’s active pockets. The binding constants of GQEDYDRLRPL to the ACE receptors were at the μM level, with a kinetic binding constant of 9.26 × 10⁻⁷ M, which is a strong binding, and a thermodynamic binding constant of 3.06 × 10⁻⁶ M. Intermolecular interaction were exothermic, enthalpy-driven, and specific binding reactions. GQEDYDRLRPL had an IC₅₀ value of 164.41 μmol/L in vitro and superior antihypertensive effects at low-gavage administration in vivo. Obtaining information on the interaction mechanism of ACE-inhibitory undecapeptides from S. rugosoannulata with the ACE receptor will help to develop and utilize ACE inhibitors of natural origin. Full article

The source and type of collagen are crucial to its application, and both play a decisive role. Collagen was prepared from both tilapia skin and bone and skate skin and cartilage, named as CI-TI-s, CI-TI-b, CI-SK-s, and CII-SK-c, respectively. Types, distributions, structures, and self-assembly of collagen were studied. It showed that yellow collagen fibers from skin arranged longitudinally, while collagen fibers from skate cartilages displayed varying colors. CI-TI-s, CI-TI-b, CI-SK-s, and CII-SK-c showed the typical amide A (3316–3336 cm⁻¹) and amide B (2929–2948 cm⁻¹) in FTIR spectra. CI-TI-b and CII-SK-c showed 218–229 nm of UV absorption, 11.56–12.20 Å of d values in XRD, and 0.12–0.14 of Rpn values in CD. The thermal denaturation temperatures of CI-TI-s and CI-SK-s were 30.7 and 20.6 °C, respectively. The self-assembly of CI-TI-s and CII-SK-c were maximum at pH 7.2 and 7.4–7.6, respectively. The unique collagen peptides of tilapia and skate were GPSGPQGAVGATGPK, PAMPVPGPMGPMGPR, SPAMPVPGPMGPMGPR, GESGPSGPAGPAGPAGVR, SSGPPVPGPIGPMGPR, GLTGPIGVPGPPGAQGEK, GLAGPQGPR, and GLSGDPGVQGIK, respectively. The unique peptides of type I and type II collagen were GPTGEIGATGLAGAR, GVLGLTGMR, LGLTGMR, GEPGAAGPAGPSGPMGPR, SSGPPVPGPIGPMGPR, and GLSGDPGVQGIK, respectively. Full article

Almond expeller is an undeveloped reservoir of bioactive peptides. In the current study, a zinc ion ligand Arg-Pro-Pro-Ser-Glu-Asp-Glu-Asp-Gln-Glu (RPPSEDEDQE) offering a noncompetitive inhibitory effect on ACE (IC₅₀: 205.50 μmol·L⁻¹) was identified from almond albumin hydrolysates via papain and thermolysin hydrolysis, subsequent chromatographic separation, and UPLC-Q-TOF-MS/MS analysis. Molecular docking simulated the binding modes of RPPSEDEDQE to ACE and showed the formation of hydrogen bonds between RPPSEDEDQE and seven active residues of ACE. Moreover, RPPSEDEDQE could bind to fifteen active sites of ACE by hydrophobic interactions, and link with the His387 and zinc ions of the zinc tetrahedral coordination. Ultraviolet wavelength scanning and Fourier-transformed infrared spectroscopy analysis revealed that RPPSEDEDQE can provide multiple binding sites for zinc ions. However, RPPSEDEDQE cannot bind with any central pocket of ACE, which was evidenced by an inhibition kinetics experiment. Additionally, the zinc-chelating capacity and inhibiting ability against ACE of RPPSEDEDQE were both not significantly reduced by the hydrolysis of gastrointestinal enzymes. A moderate to high dose of RPPSEDEDQE (100–150 mg·kg bw⁻¹) significantly reduced the systolic and diastolic blood pressure of spontaneous hypertensive rats, but chelation with zinc ions decreased its antihypertensive efficiency. These results indicate that bitter almond albumin peptides may be used for lowering blood pressure. Full article

The antioxidative proteolytic fraction, MA-1, was partially purified from Mycoleptodonoides aitchisonii. MA-1 was purified to homogeneity using a two-step procedure, which resulted in an 89-fold increase in specific activity and 42.5% recovery. SDS-PAGE revealed two proteins with a molecular weight of 48 kDa. The zymography results revealed proteolytic activity based on the MA-1 band. MA-1 was found to be stable in the presence of Na⁺, Ca²⁺, Fe³⁺, K⁺, and Mg²⁺. MA-1 was also stable in methanol, ethanol, and acetone, and its enzyme activity increased by 15% in SDS. MA-1 was inhibited by ethylenediaminetetra-acetic acid or ethylene glycol tetraacetic acid and exerted the highest specificity for the substrate, MeO-Suc-Arg-Pro-Tyr-pNA, for chymotrypsin. Accordingly, MA-1 belongs to the family of chymotrypsin-like metalloproteins. The optimum temperature was 40 °C and stability was stable in the range of 20 to 35 °C. The optimum pH and stability were pH 5.5 and pH 4–11. MA-1 exhibited stronger fibrinolytic activity than plasmin. MA-1 hydrolyzed the Aα, Bβ, and γ chains of fibrinogen within 2 h. MA-1 exhibited an antithrombotic effect in animal models. MA-1 was devoid of hemorrhagic activity at a dose of 80,000 U/kg. Overall, our results show that M. aitchisonii produces an acid-tolerant and antioxidative chymotrypsin-like fibrinolytic enzyme, and M. aitchisonii containing MA-1 could be a beneficial functional material for the prevention of cardiovascular diseases and possible complications. Full article

The effect of different ultrasound pretreatment powers (0–500 W) before hot air drying on the moisture migration and quality of Cantharellus cibarius (C. cibarius) was investigated in this study. The results showed that the ultrasound pretreatment accelerated the drying rate. When the ultrasound power was 400 W, the drying time of C. cibarius was reduced by 18.90% compared with the control group. The low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) results showed that the ultrasound pretreatment increased the water mobility in C. cibarius. The scanning electron microscopy (SEM) results revealed that the ultrasound pretreatment promoted the expansion of intercellular pores. In addition, the rehydration capacity and quality characteristics of the ultrasound-pretreated dried C. cibarius were better than those of the control group. Overall, this study concluded that ultrasound pretreatment is a promising pretreatment method for the hot air drying of C. cibarius products to reduce the total drying time significantly and improve the retention rate of the total phenolics and flavonoids of dried C. cibarius. Full article

The shiitake mushroom is the most commonly cultivated edible mushroom in the world, and is rich in protein. This study aims to obtain the peptides with α-glucosidase inhibition activity from shiitake mushroom protein hydrolysate. The conditions of enzymatic hydrolysis of shiitake mushroom protein were optimized by response surface test. The results showed that the optimal conditions were as follows: the E/S was 3390 U/g, the solid–liquid ratio was 1:20, the hydrolysis temperature and time were 46 °C and 3.4 h, respectively, and the pH was 7. The active peptides were separated by gel filtration and identified by LC-MS/MS analysis and virtual screening. The results indicated that fourteen peptides were identified by LC-MS/MS. Among them, four new peptides (EGEPKLP, KDDLRSP, TPELKL, and LDYGKL) with the higher docking score were selected and chemically synthesized to verify their inhibition activity. The IC50 values of EGEPKLP, KDDLRSP, TPELKL, and LDYGKL for α-glucosidase inhibition activity ranged from 452 ± 36 μmol/L to 696 ± 39 μmol/L. The molecular docking results showed that the hydrogen bond and arene–cation bond were the two major interactions between four peptides and 2QMJ. The hydrogen bonds were crucial to the inhibition activity of α-glucosidase. The results indicate the potential of using the peptides from shiitake mushroom protein as functional food with α-glucosidase inhibition activity. Full article

Society and consumers are increasingly concerned about food safety and the sustainability of food production systems. A significant amount of by-products and discards are generated during the processing of aquatic animals, which still needs to be fully utilized by the food industry. The management and sustainable use of these resources are essential to avoiding environmental pollution and resource waste. These by-products are rich in biologically active proteins, which can be converted into peptides by enzymatic hydrolysis or fermentation treatment. Therefore, exploring the extraction of collagen peptides from these by-products using an enzymatic hydrolysis technology has attracted a wide range of attention from numerous researchers. Collagen peptides have been found to possess multiple biological activities, including antioxidant, anticancer, antitumor, hypotensive, hypoglycemic, and anti-inflammatory properties. These properties can enhance the physiological functions of organisms and make collagen peptides useful as ingredients in food, pharmaceuticals, or cosmetics. This paper reviews the general methods for extracting collagen peptides from various processing by-products of aquatic animals, including fish skin, scales, bones, and offal. It also summarizes the functional activities of collagen peptides as well as their applications. Full article