Comparative study on the effects of grain blending on functional compound content and in vitro biological activity.

In this study, changes in bioactive compound contents and the in vitro biological activity of mixed grains, including oats, sorghum, finger millet, adzuki bean, and proso millet, with eight different blending ratios were investigated. The total phenolic compounds and flavonoid contents ranged from 14.43-16.53 mg gallic acid equivalent/g extract and 1.22-5.37 mg catechin equivalent/g extract, respectively, depending on the blending ratio. The DI-8 blend (30% oats, 30% sorghum, 15% finger millet, 15% adzuki bean, and 10% proso millet) exhibited relatively higher antioxidant and anti-diabetic effects than other blending samples. The levels of twelve amino acids and eight organic acids in the grain mixes were measured. Among the twenty metabolites, malonic acid, asparagine, oxalic acid, tartaric acid, and proline were identified as key metabolites across the blending samples. Moreover, the levels of lactic acid, oxalic acid, and malonic acid, which are positively correlated with α-glucosidase inhibition activity, were considerably higher in the DI-blending samples. The results of this study suggest that the DI-8 blend could be used as a functional ingredient as it has several bioactive compounds and biological activities, including anti-diabetic activity.

Identification and Molecular Docking Analysis of Angiotensin-Converting Enzyme Inhibitors from Finger Millet (Eleusine coracana).

Hypertension remains a significant global health concern, contributing significantly to cardiovascular diseases and mortality rates. The inhibition of angiotensin-converting enzyme (ACE) plays a crucial role in alleviating high blood pressure. We investigated the potential of finger millets (Eleusine coracana) as a natural remedy for hypertension by isolating and characterizing its ACE-inhibitory compound. First, we evaluated the ACE-inhibitory activity of the finger millet ethanol extract and subsequently proceeded with solvent fractionation. Among the solvent fractions, the ethyl acetate fraction exhibited the highest ACE inhibitory activity and was further fractionated. Using preparative high-performance liquid chromatography, the ethyl acetate fraction was separated into four subfractions, with fraction 2 (F2) exhibiting the highest ACE inhibitory activity. Subsequent 1 H-nuclear magnetic resonance (NMR) and 13 C-NMR analyses confirmed that the isolated compound from F2 was catechin. Furthermore, molecular docking studies indicated that catechin has the potential to act as an ACE inhibitor. These findings suggest that finger millets, particularly as a source of catechin, have the potential to be used as a natural antihypertensive.

Comparison of the anti-diabetic effects of various grain and legume extracts in high-fat diet and streptozotocin-nicotinamide-induced diabetic rats.

The anti-diabetic properties of whole groats and dietary fibers from various grains and legumes are well known. Nevertheless, studies on the anti-diabetic effects of their extracts are limited, and it is difficult to compare their efficacy. This study investigated the anti-diabetic potential of ethanol extracts from oats (OE), sorghum (SE), foxtail millet (FE), proso millet (PE), adzuki bean (AE), and black soybean (BE) in a high-fat diet and streptozotocin-nicotinamide-induced diabetic rat models. The extracts, obtained using 99.9 % ethanol, were orally administered to diabetic rats for four weeks. Various parameters were evaluated, including fasting blood glucose levels, glucose tolerance, insulin sensitivity, serum insulin levels, and pancreas histological analysis. OE and SE effectively reduced fasting blood glucose levels and the area under the curve (AUC) in the oral glucose tolerance test. Only OE significantly decreased the AUC in the insulin tolerance test and increased insulin concentration and homeostatic model assessment of the ß-cell function index, indicating improved insulin sensitivity and ß-cell function. Histological and immunohistochemical analysis of the pancreas supported these findings, demonstrating that OE protected against pancreatic cell damage. In contrast, FE, PE, AE, and BE did not have a significant effect on diabetes-related parameters. These findings identify OE as the most promising natural intervention for diabetes management.

Antihypertensive effects of the combined extract of Sorghum bicolor, Vigna angularis, and Eleusine coracana in spontaneously hypertensive rats.

This study investigated the antihypertensive effects of the combined extract of sorghum, adzuki bean, and finger millet (SAFE) on spontaneously hypertensive rats. The rats were divided into four groups (n = 8): WKY, SHR, SAFE (500 mg/kg SAFE), and CAP (50 mg/kg captopril). SAFE significantly decreased the lean-to-fat mass ratio with no notable changes in body weight, food intake, or food efficiency ratio, and it effectively lowered both systolic and diastolic blood pressures, comparable to CAP. Moreover, it significantly reduced the cardiac mass index and alleviated cardiac fibrosis. SAFE did not induce hepatotoxicity, as indicated by the maintenance of aspartate aminotransferase and alanine aminotransferase levels in the normal range, confirming its safety. Taken together, these findings suggested that SAFE can be used as a dietary supplement for blood pressure regulation and cardiovascular disease prevention.

Development of gelatinized-core liposomes for the oral delivery of EGCG with improved stability, release property, and cellular antioxidant activity.

Epigallocatechin gallate (EGCG) exhibits antioxidant, anti-cancer, and anti-inflammatory properties; however, low cellular permeability and stability limit its bioavailability. Liposomes have the potential for enhancing bioactive compounds' bioavailability. Yet, low entrapment efficiency (EE) and burst release of hydrophilic substances make them impractical for food industry use. Here, we incorporated gelatin into liposomes to overcome these limitations. EGCG-loaded conventional liposomes (EGCG/CLs) and gelatinized-core liposomes (EGCG/GLs) had small particle sizes and high absolute zeta potentials. Encapsulation in EGCG/GLs significantly improved the EE of EGCG compared to that in EGCG/CLs (p < 0.05). EGCG/GLs retained EGCG in the hydrophilic region, whereas EGCG/CLs exhibited significantly higher release of EGCG during storage (p < 0.05). Additionally, in comparison to EGCG/CLs, gelatin incorporation significantly enhanced the sustained release, cellular permeability, and cellular antioxidant activity of EGCG (p < 0.05). This study emphasizes the capability of gelatinized-core liposomes as a potent delivery system for enhancing the stability and bioavailability of EGCG/CLs, broadening the prospects for utilizing them in the food industry.

α-Tocopherol-loaded multi-layer nanoemulsion using chitosan, and dextran sulfate: Cellular uptake, antioxidant activity, and in vitro bioaccessibility.

The potential of multi-layer nanoemulsions (NEs) for improving the cellular uptake, antioxidant activity, and in vitro bioaccessibility of α-tocopherol (ToC) was examined. ToC-loaded multi-layer NEs were prepared using lecithin (primary-NEs, P-NEs), chitosan (secondary-NEs, S-NEs), and dextran sulfate (tertiary-NEs, T-NEs) as wall materials. The bioadhesion, cellular permeability, and uptake of the multi-layer NEs were significantly higher than that of the free coumarin 6 (C6). As a result of cellular uptake, the mean fluorescence intensity of T-NEs was the highest among the three types of multi-layer NEs and was 9.8-fold higher than that of free C6. The cellular antioxidant abilities of P-NEs, S-NEs, and T-NEs were 40, 45, and 50 %, respectively. Multi-layer nanoencapsulation sustains free fatty acid release after digestion. Moreover, the bioavailability of T-NEs exhibited a two-fold increase compared with that of the free ToC. These findings indicate that by multi-layer NEs using a layer-by-layer method, the cellular uptake, in vitro bioaccessibility, and antioxidant activity of ToC can be improved. Furthermore, T-NEs using chitosan and dextran sulfate can potentially enhance the cellular uptake, in vitro bioaccessibility, and antioxidant activity of ToC. These findings would facilitate the application of multi-layer NEs for lipophilic bioactive compounds using biopolymers.

Taste masking and stability improvement of Korean red ginseng (Panax ginseng) by nanoencapsulation using chitosan and gelatin.

In this study, red ginseng extract (RGE)-loaded nanoparticles (NPs) were prepared by ionic gelation between chitosan (CS) and gelatin (Gel), and the physical characteristics of the RGE-loaded CS-Gel NPs (RGE-CS/Gel NPs), including particle size and polydispersity index (PDI), using different ratios of CS and Gel were examined. The particle size and PDI were 398.1 ± 41.3 nm and 0.433 ± 0.033, respectively for the optimal ratio of CS (0.075 mg/mL) and Gel (0.05 mg/mL). In vitro taste masking test and in vivo sensory evaluation using 10 panelists demonstrated that the CS/Gel NPs significantly reduced the bitter taste of RGE. Additionally, the CS/Gel NPs improved the thermal and acid stabilities, which were almost 6 and 8 times higher than those in the free RGE (p < 0.05), respectively. Likewise, our findings revealed that the RGE-CS/Gel NPs effectively maintain their inhibitory function against platelet aggregation (76.30 %) in an acidic environment. Therefore, the CS/Gel NPs can be used as a potential delivery system to mask the bitterness and improve the stability of RGE, which may enhance its application as a more palatable functional food ingredient with high anti-platelet activity.

Blended extract of oat, sorghum, adzuki bean, finger millet, and proso millet improved hyperglycemia and insulin resistance in the streptozotocin-nicotinamide-induced diabetic rats.

Grains contain bioactive components that potentially have protective effects on chronic diseases such as diabetes. The anti-diabetic effects of blended grain ethanol extract (BGE) were evaluated in streptozotocin-nicotinamide (STZ-NA)-induced diabetic rats. BGE was prepared by mixing oat, sorghum, adzuki bean, finger millet, and proso millet (30:30:15:15:10). The rats were assigned into four groups, normal control, diabetic model control (DM), STZ-NA rats administered 200 mg/kg body weight (bw) of metformin, and STZ-NA rats administered 500 mg/kg bw of BGE (BGE). After 6 weeks of administration, the homeostatic model assessment of insulin resistance (12%) in BGE decreased compared to DM. Strikingly, the fasting blood glucose (23%) and oral glucose tolerance test (15%) were improved in BGE compared to DM. BGE also increased insulin immunoreactivities in pancreatic ß-cells. In sum, BGE exhibits anti-hyperglycemic effects by improving fasting glucose levels and insulin secretion from pancreatic ß-cells in the STZ-NA-induced diabetic rats.

Black and Yellow Soybean Consumption Prevents High-Fat Diet-Induced Obesity by Regulating Lipid Metabolism in C57BL/6 Mice.

To evaluate the antiobesity effects of yellow and black soybean, C57BL/6 mice were provided with a normal diet, high-fat diet, HFD-containing yellow soybean powder (YS), and black soybean powder (BS) for six weeks. Compared with the HFD group, both YS and BS decreased body weight by 30.1% and 37.2% and fat in tissue by 33.3% and 55.8%, respectively. Simultaneously, both soybeans significantly reduced the serum triglyceride and total cholesterol levels and regulated the lipogenic mRNA expressions of Pparγ, Acc, and Fas genes in the liver, supporting reduced body adiposity. Furthermore, BS significantly increased Pgc-1α and Ucp1 mRNA expression levels in epididymal adipose tissue, indicating thermogenesis is the key mechanism of BS. Taken together, our findings suggest that both soybeans prevent high-fat diet-induced obesity in mice by regulating lipid metabolism, and BS, in particular, has a greater antiobesity potential than YS.

Comparison of physicochemical properties of sorghum extract by ethanol concentration and its anti-adipogenic effect in 3T3-L1 cells.

Sorghum is a vital cereal source that has various phenolic compounds and potential health-promoting benefits. This study evaluated the phenolic content, antioxidant and anti-obesity effects of sorghum extract (SE) prepared using three solvent systems: 50% (SE50), 80% (SE80), and 100% (SE100) ethanol. The results showed that SE50 exhibited the highest total polyphenol and flavonoid content among the sorghum extracts using different ethanol concentrations as extraction solvents. In addition, SE50 showed significantly higher antioxidant capacity than the other extracts. Interestingly, SE50 significantly inhibited lipid accumulation in 3T3-L1 adipocytes; however, SE80 and SE100 had no beneficial effects. Moreover, SE50 significantly downregulated the mRNA expression levels of adipogenic genes (Cebpα, Pparγ, and Fabp4) and lipogenic genes (Srebp1c, Fas, and Scd1). These results suggest that SE50 is superior to other ethanol extracts in phenolic contents, antioxidant and anti-obesity activities, and it could be used as a nutraceutical for anti-obesity.

Nanoencapsulation of Grapefruit Seed Extract and Cinnamon Oil for Oral Health: Preparation, In Vitro, and Clinical Antimicrobial Activities.

This study aimed to formulate mucoadhesive antimicrobial nanoparticles using natural antimicrobials and biopolymers for oral health and verify their antimicrobial activity in clinical studies. A combination of grapefruit seed extract and cinnamon oil (GCN) and chitosan/carrageenan (CS/CR) were selected as synergistic antimicrobial combinations and mucoadhesive wall materials for nanoparticles, respectively. GCN nanoparticles (NPs; size = 357 nm and polydispersity index = 0.188) prepared by ionic gelation between CS and CR exhibited synergistic antimicrobial activity between grapefruit seed extract and cinnamon oil and significantly higher antimicrobial activity against Streptococcus mutans and sobrinus than free GCN in a time-kill assay. The clinical antibacterial activity of GCN was significantly increased and sustained by nanoencapsulation in the mouth-rinse test and GCN NP-treated drinking yogurt. These results suggest that GCN-loaded CS/CR nanoencapsulation is a promising technique that can inhibit oral bacteria with or without the presence of other food ingredients.

Comparison of the effects of commercial whey protein and native whey protein on muscle strength and muscle protein synthesis in rats.

Commercial whey protein (CWP) is generally produced in the cheese making process with heat treatment. Recently, native whey protein (NWP) can be obtained through microfiltration without heat treatment. The difference in physicochemical properties of CWP and NWP was confirmed in previous studies; however, in vivo research on the effect on muscle strength and protein synthesis is still lacking. In this study, rats were orally administered 1.56 g protein/kg body weight of lyophilized beverages containing CWP and NWP for 8 weeks. The biological value and net protein utilization in the NWP were significantly higher than in the CWP. Moreover, NWP increased muscle mass and grip strength compared to CWP. NWP also increased the phosphorylation of the mammalian target of rapamycin and ribosomal protein S6 kinase, pivotal proteins for muscle protein synthesis. These results suggest that NWP enhance muscle strength and protein synthesis more effectively than CWP.

Erratum to: Effect of Modified Casein to Whey Protein Ratio on Dispersion Stability, Protein Quality and Body Composition in Rats.

[This corrects the article DOI: 10.5851/kosfa.2021.e42.].

Encapsulation of resveratrol within size-controlled nanoliposomes: Impact on solubility, stability, cellular permeability, and oral bioavailability.

This study examined the influence of the nanoliposomes (LPs) particle size on the solubility, antioxidant stability, in vitro release profile, Caco-2 cellular transport activity, cellular antioxidant activity, and in vivo oral bioavailability of resveratrol (RSV). LPs with sizes of 300, 150, and 75 nm were prepared using the thin-lipid film hydration method, followed by ultrasonication for 0, 2, and 10 min, respectively. Formulating small LPs (< 100 nm) was effective to enhance the solubility, in vitro release profile, cellular permeability, and cellular antioxidant activity of RSV. A similar pattern was observed for in vivo oral bioavailability. However, the size reduction of RSV-loaded LPs did not promote the antioxidant stability of RSV, owing to their large surface area used to interact with harsh environments. This study provides the better understanding of the appropriate particle size range of LPs to improve their in vitro and in vivo performances of RSV as an effective carrier for oral administration.

Optimization and release characteristics of catechin-loaded calcium pectinate beads by internal gelation.

The aim of this study was to optimize the composition of catechin-loaded calcium pectinate gel (CPG) beads formed using internal gelation and to evaluate the sustained-release behavior of catechin. The pectin concentration, catechin-to-pectin ratio, and calcium carbonate-to-pectin ratio were optimized for the sustained catechin release (2.89, 28.92, and 32.79%, respectively). The catechin release profiles were analyzed using the simple enzyme kinetic-like semi empirical model newly proposed in this study. The actual release rate was found to be the fastest in the simulated intestinal fluid (SIF), followed by the simulated gastric fluid (SGF) and the pH 4.5 buffer, whereas the thermodynamic equilibrium was achieved fastest in the pH 4.5 buffer, followed by SGF and SIF. Glutaraldehyde treatment suppressed catechin release in all tested media. These results suggest that internally gelled CPG beads are suitable for catechin delivery, and crosslinkers, such as glutaraldehyde, can effectively sustain their release.

Effects of roasting conditions on Korean rice wine (Makgeolli) with licorice (Glycyrrhiza uralensis Fischer).

The present study investigated the effect of roasting process (temperature: 150, 180, and 210 °C; time: 10, 20, and 30 min) of licorice on the browning index (BI), total flavonoid content (TFC), and antioxidant activity for ingredient of Makgeolli. The antioxidant activity was measured by assaying DPPH radical scavenging activity (DPPH·IC50) and Trolox equivalent antioxidant capacity (TEAC). In addition, the quality characteristics of Makgeolli with different amount (0%, 6%, 12%, and 18%) of roasted licorice extract (RLE) were measured comparison to un-roasted licorice extract (ULE). When superimposing the contour plots of the responses in which the limits of each response were determined, the optimum conditions for roasting licorice were 178 °C for 24 min. Moreover, results revealed that Makgeolli with 12% RLE under optimum roasting condition was superior with respect to antioxidant activity and more acceptable based on sensory properties than ULE.

Chitosan-Tripolyphosphate Nanoparticles Prepared by Ionic Gelation Improve the Antioxidant Activities of Astaxanthin in the In Vitro and In Vivo Model.

The present study aimed to investigate the effects of chitosan (CS)-tripolyphosphate (TPP) nanoparticles (NPs) on the stability, antioxidant activity, and bioavailability of astaxanthin (ASX). ASX-loaded CS-TPP NPs (ACT-NPs) prepared by ionic gelation between CS (0.571 mg/mL) and TPP (0.571 mg/mL) showed 505.2 ± 184.8 nm, 20.4 ± 1.2 mV, 0.348 ± 0.044, and 63.9 ± 3.0% of particle size, zeta potential, polydispersity index and encapsulation efficiency, respectively. An in vitro release study confirmed that the release of ASX in simulated gastric (pH 1.2) and intestinal (pH 6.8) fluid was prolonged within ACT-NPs. The in vitro antioxidant activities of ACT-NPs were significantly improved compared with free ASX (FA) (p < 0.05). Furthermore, the cellular and in vivo antioxidant analysis verified that ACT-NPs could enhance the cytoprotective effects on the BHK-21 cell line and demonstrate sustained release properties, leading to prolonged residence time in the rat plasma. The results suggest that the stability, antioxidant properties, and bioavailability of ASX can be effectively enhanced through encapsulation within CS-TPP NPs.

Whey Proteins-Fortified Milk with Adjusted Casein to Whey Proteins Ratio Improved Muscle Strength and Endurance Exercise Capacity without Lean Mass Accretion in Rats.

This study investigated the effects of the casein to whey proteins (CW) ratio in milk on body composition, muscle strength, and endurance exercise capacity in rats. Thirty rats were assigned into five groups, and each treatment was administered for eight weeks: (1) control (isocaloric lactose supplementation), (2) CW8:2 (regular milk), (3) CW6:4, (4) CW5:5, and (5) nitrogen-free (lactose). The milk concentration was converted from a human equivalent dose (400 mL/60 kg body weight/day). All the milk-administered groups showed significantly greater growth performance, including body weight and weight gain compared to the isocaloric lactose control (p < 0.05). However, different CW ratios in milk had no effect on growth performance. Additionally, body composition, i.e., lean body mass and adiposity, was not affected by the CW ratio. Interestingly, CW6:4 and CW5:5 had significantly higher plasma branched-chain amino acids concentrations than control and CW8:2 (p < 0.05). In addition, CW5:5 showed significantly increased grip strength by 12-24% and time to exhaustion by 8-62% compared to the other groups (p < 0.05), indicating that the higher whey proteins ratio improved physical performance. We concluded that whey proteins-fortified milk enhances muscle strength and endurance exercise capacity without altering lean mass in rats.

Antimicrobial and indicator properties of edible film containing clove bud oil-loaded chitosan capsules and red cabbage for fish preservation.

For safe preservation and consumption of fish, freshness monitoring and antimicrobial control is crucial. Edible films comprising natural antimicrobial and spoilage indicator agents represent a convenient method for such preservation. Edible chitosan-based films were prepared using red cabbage (RC) and clove bud oil (CBO)-loaded chitosan/carrageenan capsules as spoilage indicator and antimicrobial agents, respectively. CBO-loaded capsules were prepared by the ionic gelation of chitosan and carrageenan. Films containing CBO capsules exhibited significantly higher antimicrobial activity than films containing non-encapsulated free CBO, as confirmed by minimum inhibitory concentration and time-kill assays. The highest antimicrobial activity was observed in the largest capsules (1.7 µm). After incubation for 48 h, the pH of fish peptone agar containing Pseudomonas fluorescens increased from approximately 6.0 to 9.0, and a color change from purple to deep blue was clearly observed during the growth of fish-spoiling bacteria. Thus, our results suggested that edible films containing CBO-loaded capsules and RC showed the potential to inhibit microbial growth in fish and to visibly indicate fish freshness.

Effect of Surface Layer Proteins Derived from Paraprobiotic Kefir Lactic Acid Bacteria on Inflammation and High-Fat Diet-Induced Obesity.

The antiobesity action of nonviable probiotic lactic acid bacteria (PLAB) may be attributed to bacterial cellular components recognized by host cells. The anti-inflammation and antiobesity properties of surface layer proteins (SLPs) that are cellular components isolated from kefir PLAB were determined in macrophage RAW 264.7 cells and obese mice. Kefir SLPs significantly decreased secretion of IL-6 and production of NF-kB p65 protein by LPS-stimulated RAW 264.7 cells in a dose-response manner. C57BL/6J mice were fed a high-fat (HF) diet with oral administration of either saline (CON) or kefir SLPs for 6 weeks. SLPs significantly improved body weight gain and adipose tissue weight, plasma triglyceride concentrations, and insulin resistance. Profiling of adipocyte gene expression showed that the antiobesity effect was significantly related to the expression of genes associated with adipogenesis, autophagy, and inflammatory/immune response, and fatty acid oxidation. Taken together, SLPs are a novel bioactive component in kefir PLABs to target obesity and obesity-related disorders.