Development of chitosan-based edible film incorporated with purified flavonoids from Moringa oleifera: Structural, thermal, antibacterial activity and application.

Purified flavonoids (PF) from Moringa oleifera leaves were incorporated in chitosan (CS) polymer at different concentrations (0.5-4%) to produce a novel edible film. The physical, structure, mechanical, and bio-functional characterizations of the film were evaluated. The incorporation of PF significantly (p < 0.05) improved the thickness, solubility, swelling, and color of CS-films. Incorporating 4% of Moringa oleifera purified flavonoids (MOPF) improved the water vapor permeability from 8.85 to 2.47 g-1 s-1 Pa-1, and increased the film surface heterogeneity observed by SEM. Results also indicated that PF enhanced the mechanical properties and thermal stability of CS-films. The FTIR results indicated alterations in the CS-MOPF composite films' characteristics. Additionally, the incorporation of MOPF increased the antioxidation capacity. Furthermore, 4% of MOPF inhibited the activity of pathogenic bacteria in packed beef burgers. These results suggest that CS-MOPF composite films with enhanced technological and bio-functional properties could be industrially applied to increase the shelf-life of packaged foods.

Comparison of nutritional value of snakehead fish from Guangdong and Deqing varieties.

Environmental pollution and overfishing of wild fish resources have led to a significant decrease in snakehead fish, thus leading to the increased demand for breeding the snakehead fish. Guangdong and Deqing snakehead fish are two common consumed varieties. However, their nutritional value was unclear. Therefore, this study aimed to evaluate the nutritional value of snakehead fish from Guangdong and Deqing varieties feeding with different fodders by analyzing and comparing the proximate composition, fatty acids and amino acids. Results showed that the contents of carbohydrate, energy and fat contents in Guangdong variety were lower than that in Deqing variety feeding commercial fodder or offal. Besides, Guangdong variety contained the highest contents of polyunsaturated fatty acids (27.99 ± 1.99%) and EPA + DHA (2.70 ± 0.04%), as well as total essential amino acid content (2550.29), compared to Deqing variety feeding commercial fodder or offal. Overall, snakehead fish from Guangdong variety displayed the highest nutritional value, and thus was a reasonable choice for farmers and consumers. The findings of this study would help farmers to choose the suitable feeding variety and patterns of snakehead fish from the perspective of fish nutritional value, which is beneficial to the sustainable fish farming.

Polysaccharides from Brassica rapa root: Extraction, purification, structural features, and biological activities. A review.

Brassica rapa (B. rapa) roots are attracting increased attention from nutritionists and health-conscious customers because of their remarkable performance in supplying necessary nutrients. Polysaccharides are major biologically active substances in B. rapa roots, which come in a variety of monosaccharides with different molar ratios and glycosidic bond types. Depending on the source, extraction, separation, and purification methods of B. rapa roots polysaccharides (BRP); different structural features, and pharmacological activities are elucidated. Polysaccharides from B. rapa roots possess a range of nutritional, biological, and health-enhancing characteristics, including anti-hypoxic, antifatigue, immunomodulatory, hypoglycemic, anti-tumor, and antioxidant activities. This paper reviewed extraction and purification methods, structural features, and biological activities as well as correlations between the structural and functional characteristics of polysaccharides from the B. rapa roots. Ultimately, this work will serve as useful reference for understanding the connections between polysaccharide structure and biological activity and developing novel BRP-based functional foods.

Isolation, structure characterization and in vitro immune-enhancing activity of a glucan from the peels of stem lettuce (Lactuca sativa).

BACKGROUND: Stem lettuce is a medicinal and edible plant. The peels, accounting for 300-400 g kg-1 raw stem lettuce and containing polysaccharides 200 g kg-1 , are discarded as industrial waste, causing environment pollution and resource waste. RESULTS: A polysaccharide named PPSL10-2 was obtained from the peels of stem lettuce after hot water extraction, and gradation with cascade ultrafiltration and purification using DEAE-Sepharose cellulose. The purity and molecular weight of PPSL10-2 is 96.10% and 2.2 × 104 Da respectively, as detected by high-performance gel permeation chromatography. PPSL10-2 was found to be an α-(1→4)-d-glucan that branched at O-6 with a terminal 1-linked α-d-Glcp as side chain, and devoid of helix conformation, which was characterized by monosaccharide composition analysis, Fourier-transform infrared spectroscopy, Congo red test, scanning electron microscopy, methylation analysis and NMR spectroscopy. Furthermore, PPSL10-2 exhibited potent immune-enhancing effect by improving proliferation and phagocytosis, promoting the secretion of nitric oxide and cytokines, as well as the expression of related genes in RAW264.7 macrophages. CONCLUSION: The findings of the present study suggest that peels as an agricultural by-product of stem lettuce are good sources of polysaccharides, which could be developed as immunopotentiator for improving human health. © 2023 Society of Chemical Industry.

Preparation Process Optimization of Peptides from Agaricus blazei Murrill, and Comparison of Their Antioxidant and Immune-Enhancing Activities Separated by Ultrafiltration Membrane Technology.

Agaricus blazei murrill (ABM), a large fungus, is reported to have extensive biological activities but the antioxidant and immune-regulatory capacities have been less studied and the components responsible for the functions are unclear. This study prepared ABM peptides (ABMP) using ultrasound-assisted enzymatic extraction (UAEE) strategy and cascade ultrafiltration (UF) membrane technology. The UAEE extraction conditions were optimized using response surface methodology (RSM) with four factors and three levels to achieve the maximum ABMP yield (34.03%); the optimal conditions were an enzyme amount of 4%, ratio of ABM to water of 1:30, ultrasonic power of 360 W, and ultrasonic time of 30 min. Four ABMP fractions were obtained after UF with different pore size and their antioxidant and immune-regulatory abilities were evaluated and compared. The results showed that they could effectively scavenge DPPH, hydroxyl, and ABTS radicals, especially for ABMP-2; the scavenging rate of the above radicals were 79.31%, 63.60%, and 96.08%, respectively. In addition, four ABMP fractions also activated macrophage activity through strengthening phagocytosis and the production of NO, IL-6, IL-1ß, and TNF-α in a dose-dependent manner. Notably, the ABMP-2 fraction with a MW of 3-5 kDa and peptide purity of 82.88% was found to have the best effect, showing the maximum phagocytosis (189.37%) as well as NO (7.98 µM), IL-6 (195.05 pg/mL), IL-1ß (876.15 pg/mL), and TNF-α (1620 pg/mL) secretion at a treatment concentration of 150 µg/mL. The findings indicated that the ABMP, especially for the separate ABMP-2, could be used as dietary supplements and have the potential to be exploited as immune-enhancing agents.

Physicochemical properties and immune-enhancing activity of graded polysaccharides from the peels of stem lettuce (Lactuca sativa) by cascade membrane technology.

In this study, cascade membrane technology was applied to classify polysaccharides from the peels of stem lettuce (PPSLs), and three graded polysaccharides (PPSL100, PPSL10, and PPSL1) were obtained using ultrafiltration membranes of 100, 10, and 1 kDa in sequence. The physicochemical properties and immune-modulatory activity of three PPSLs fractions were analyzed and compared. Results showed that all three fractions have characteristic absorption peak of polysaccharides determined by FT-IR, and their monosaccharide composition only consisted of glucose determined by HPLC. PPSL10 had the highest contents of total sugar (88.09 ± 3.52%), uronic acid (2.55 ± 0.10%), and sulfate group (4.15 ± 0.20%). Besides, all three fractions exhibited immune-enhancing activities using RAW264.7 macrophages model, and PPSL10 was the best able to promote phagocytosis of neutral red and nitric oxide generation, which might relate to the high contents of above compositions and medium molecular weight (32 kDa). The findings indicated that PPSL10 could be developed as immune-modulator in the field of functional foods.

Digestive Characteristics of Hericium erinaceus Polysaccharides and Their Positive Effects on Fecal Microbiota of Male and Female Volunteers During in vitro Fermentation.

Hericium erinaceus polysaccharides (HEPs) have attracted widespread attention in regulating gut microbiota (GM). To investigate digestibility and fermentation of HEPs and their effects on GM composition, three polysaccharide fractions, namely, HEP-30, HEP-50, and HEP-70, were fractionally precipitated with 30%, 50%, and 70% ethanol concentrations (v/v) from hot water-soluble extracts of Hericium erinaceus, respectively. Three kinds of prepared HEPs were structurally characterized and simulated gastrointestinal digestion, and their effects on human fecal microbiota fermentations of male and female and short-chain fatty acid (SCFA) production in vitro were clarified. Under digestive conditions simulating saliva, stomach, and small intestine, HEPs were not significantly influenced and safely reached the distal intestine. After 24 h of in vitro fermentation, the content of SCFAs was significantly enhanced (p < 0.05), and the retention rates of total and reducing sugars and pH value were significantly decreased (p < 0.05). Thus, HEPs could be utilized by GM, especially HEP-50, and enhanced the relative abundance of SCFA-producing bacteria, e.g., Bifidobacterium, Faecalibacterium, Blautia, Butyricicoccus, and Lactobacillus. Furthermore, HEPs reduced the relative abundances of opportunistic pathogenic bacteria, e.g., Escherichia-Shigella, Klebsiella, and Enterobacter. This study suggests that gradual ethanol precipitation is available for the preparation of polysaccharides from Hericium erinaceus, and the extracted polysaccharide could be developed as functional foods with great development value.

Solid-state-cultured mycelium of Antrodia camphorata exerts potential neuroprotective activities against 6-hydroxydopamine-induced toxicity in PC12 cells.

Antrodia camphorata (A. camphorata) is an edible fungus containing various bioactive compounds generally used for health benefits. This study aimed to explore the potential neuroprotective activities of solid-state-cultured mycelium of A. camphorata (SCMAC) against Parkinson's disease (PD), as well as the underlying mechanism using an in vitro 6-hydroxydopamine (6-OHDA)-induced PC12 cell model. The results showed that SCMAC extracts alleviated cell toxicity induced by 6-OHDA and the loss of dopaminergic neurons, which was confirmed by the increase of cell viabilities, inhibition of cell apoptosis, the upregulation of tyrosine hydroxylase (TH) and dopamine transporter (DAT) levels and the downregulation of α-Synuclein level. After purification, 11 compounds were identified by the NMR technique, including a quinone, four phenolic acid derivatives, three ubiquinone derivatives, two alkaloids, and a triterpenoid. The present study suggests that SCMAC could be an attractive candidate for the prevention or treatment of PD. PRACTICAL APPLICATIONS: Parkinson's disease seriously affects the lifetime and quality of the elder population for a long history. Long-term consumption of L-DOPA will result in side effects, such as developing abnormal involuntary movements called dyskinesia. This study showed that natural SCMAC extracts could be a potential therapeutic agent for the treatment of neurodegenerative disorder.

Extraction, Purification, Bioactivities and Application of Matrix Proteins From Pearl Powder and Nacre Powder: A Review.

Natural pearls are formed when sand or parasites (irritants) accidentally enter into the oyster body and form pearls under the cover of the nacre layer. Pearl powder is a powdery substance by grinding pearls into small grains, however, the nacre powder is the inner layer of outer corner layer and middle prism layer. Pearl medicine in China has a history of more than 2,000 years, pearl has the effects of calming the mind, clearing the eyes, detoxifying the muscle and so on. In this paper, the researches on the extraction of pearl powder and nacre powder, the isolation and purification of matrix protein and the various biological activities (osteogenic activity, antioxidant, anti-inflammatory, anti-apoptotic, promoting the migration of fibroblasts, and so on) are reviewed in detail. To provide readers with a faster understanding, the method of extraction and purification and the application of nacre powder and pearl powder are clearly presented in the form of figures and tables. In line with the concept of waste or by-product, there are more reports of nacre extract than pearl extract, due to the expensive and limited in origin of pearls. Mainly on the direct use of nacre powder and pearl powder or on the use of extracts (mainly water soluble proteins) through experiments in vivo or in vitro, and shows whether it is effective through the results of various indexes. There is no further study on substances other than extracts, and the structural analysis of extracts needs further exploration.

Effects of ultrasonic pre-treatment on physicochemical properties of proteins extracted from cold-pressed sesame cake.

Sesame is an oil crop with high nutritional value. Protein is one of the main ingredients of sesame, however research on protein of cold-pressed sesame cake is limited. This study aimed to investigate the effects of ultrasonic pre-treatment (UPT) on physicochemical properties of proteins (yield, solubility, amino acid composition, surface properties, structural and thermal stability) extracted from the cold-pressed sesame cake, after removing lignans by ultrasonic-assisted extraction. By comparison, the extraction yield of protein was significantly (p ＜ 0.05) increased from 22.24% (without UPT) to 25.95% (with UPT), while the purity (54.08% without UPT, 55.43% with UPT), total amount of essential amino acids (22.48% without UPT, 23.10% with UPT) and non-essential amino acids (37.48% without UPT, 36.54% with UPT) were not significantly influenced. Besides, UPT slightly reduced the solubility, foaming capacity and stability (FC and FS) of protein. In addition, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal stability (TG) analysis demonstrated that UPT could disorder and loose protein molecular structure, resulting in the change of morphology, secondary structure and thermal stability. In conclusion, this study provides a way for the separation and future application of sesame cake protein. UPT is a good option to remove the lignans from sesame cake proteins.

Protein isolate from Stauntonia brachyanthera seed: Chemical characterization, functional properties, and emulsifying performance after heat treatment.

The seed of Stauntonia brachyanthera is usually regarded as waste after fructus processing. Here, the potential utilization value of the protein isolate (SSPI) from seeds was evaluated by investigating its physicochemical and functional properties. SSPI was a complex protein containing 7 distinct subunits that had high contents of most essential amino acids. The maximum foaming capacity of SSPI was 406.7 ± 41% at pH 9.0, and the water holding/oil adsorption capacities were 4.66 g/g and 9.06 g/g, respectively. SSPI aggregates with a particle size of 154.1 ± 5.2 nm was prepared after heat treatment, which was performed as a Pickering-like stabilizer for the structuring of water-in-oil-in-water emulsions. The outer droplet size of emulsions decreased as the aggregate concentration increased. Emulsion gels could be observed with the increasing aggregate concentration and oil fraction. Further study found that the stabilities of inner water-in-oil droplets and creaming were progressively increased by increasing the aggregate concentration during storage.

Orbitides isolated from flaxseed induce apoptosis against SGC-7901 adenocarcinoma cells.

Unique plant-derived cyclic peptides family exhibiting various key biological activities has great possibility for anticancer therapy. In this study, we investigated the effects of orbitides isolated from flax (Linum usitatissimum L.) on the growth of SGC-7901 cancer cells and the potential mechanism. Results showed that flaxseed orbitides killed off cancer cells by inducing apoptosis in a dose-dependent manner, which was confirmed by the appearance of nuclear shrinkage and DNA fragmentation, and the inhibitory effect was stronger than that of pure orbitide [1-9-NαC]-linusorb B2 or [1-9-NαC]-linusorb B3. Besides, the mitochondrial apoptosis pathway-related protein cytochrome C (Cyt C) was released from mitochondria to cytosol, associated with the activation of caspases 9 and 3, and the cleavage of PARP. Taken together, these results indicated that flaxseed orbitides induced apoptosis via the mitochondrial pathway, releasing Cyt C, increasing Bax/Bcl-2 ratio and elevating the expression of cleaved caspase 9 and 3 in SGC-7901 cells.

Flaxseed orbitides, linusorbs, inhibit LPS-induced THP-1 macrophage inflammation.

Linusorbs (flaxseed orbitides) are a family of naturally-occurring cyclic peptides. Previously, we reported that their anticancer effects were associated with their structures. In this study, we investigated the anti-inflammatory activities of 2 different linusorbs ([1-9-NαC]-linusorb B2 and [1-9-NαC]-linusorb B3) in lipopolysaccharide (LPS)-induced THP-1 macrophage activation as well as the underlying mechanism of this inflammatory response. Both molecules suppressed pro-inflammatory mediators (TNF-α, IL-1ß, IL-6, NO and COX-2) and were involved in downregulating the NF-κB signaling pathway. The suppressive effects on pro-inflammatory mediators were comparable and the concentration range of action was similar (1-4 µM). However, the concentration of compound that induced downregulation of the NF-κB pathway was different for each compound. While [1-9-NαC]-linusorb B3 could inhibit the activation of the NF-κB pathway at concentrations of 1 and 2 µM, [1-9-NαC]-linusorb B2 induced a comparable inhibitory effect at a concentration of 4 µM.

Effects of Chinese Dietary Pattern of Fat Content, n-6/n-3 Polyunsaturated Fatty Acid Ratio, and Cholesterol Content on Lipid Profile in Rats.

This study aims to investigate the effect of Chinese diet pattern of fat content (30% or 36.06%), n-6/n-3 polyunsaturated fatty acid (PUFA) ratio (5 : 1 or 9 : 1), and cholesterol content (0.04 or 0.057 g/kg total diet) on lipid profile using a rat model. Results showed that rats' body weights (BWs) were controlled by the simultaneous intakes of cholesterol level of 0.04 g/kg total diet and n-6/n-3 ratio of 5 : 1. In addition, under high-fat diet, increased cholesterol feeding led to increased total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels and decreased triacylglycerols (TG) in rats' plasma. However, high density lipoprotein cholesterol (HDL-C) level and the ratios of HDL-C/LDL-C and HDL-C/TC in rats' plasma increased in response to simultaneous intakes of low n-6/n-3 ratio (5 : 1) and cholesterol (0.04 g/kg total diet) even under high-fat diet. Moreover, as the n-6/n-3 PUFA ratio in the diet decreased, the proportion of n-3 PUFAs increased in plasma, liver, and muscle and resulted in the decrease of n-6/n-3 PUFA ratio.

Methionine sulfone-containing orbitides, good indicators to evaluate oxidation process of flaxseed oil.

This study aimed to explore the possibility of using methionine sulfone (Msn)-containing orbitides as indicators to evaluate the oxidation process of flaxseed oils. Results showed that after 4 days' heating, oxidation values slightly increased (p > .05) with significant decrease in methionine (Met)-containing peptides (p < .05) instead of γ-tocopherol (p > .05). However, as oxidation time continues increasing, oxidation values significantly increased (p < .05) with significant reduction of γ-tocopherol (p < .05). It demonstrated that Met-containing peptides were more readily oxidized compared with γ-tocopherol and showed certain antioxidant activity. Besides, high logarithmic correlations were found between oxidation values and Msn-containing orbitides (0.94-1.00), such as between total carbonyl compounds and orbitide [1-8-NαC],[1-MetO2]-CLE (64.95 lnx - 52.14, R2 = 0.99, Dingya23 oil). Therefore, in comparison with common oxidation indices, Msn-containing orbitides may be better indicators for evaluating the oxidation process of flaxseed oil with superior separation efficiency, specific information and high stability.

Esterification of Quercetin Increases Its Transport Across Human Caco-2 Cells.

Plant polyphenols showed useful biochemical characteristics in vitro; however, the assessments of their clinical applications in vivo are restricted by their limited bioavailability due to their strong resistance to 1st-pass effects during absorption. In order to improve the bioavailability of quercetin (QU), the ester derivative of QU (3,3',4',5,7-pentahydroxy flavones, TAQU) was synthesized, followed by examining the oil-water partition coefficient as well as the transport mechanisms of QU and its ester derivative (TAQU) using human Caco-2 cells. The transport characteristics of QU and TAQU transport under different conditions (different concentrations, time, pH, temperature, tight junctions, and potential transporters) were systematically investigated. Results showed that QU had a lower permeability coefficient (2.82 × 10(-6) cm/s) for apical-to-basolateral (AP-BL) transport over 5 to 50 µM, whereas the transport rate for AP to BL flux of TAQU (5.23 × 10(-6) cm/s) was significantly greater than that of QU. Paracellular pathways were not involved during the transport of both QU and TAQU. QU was poorly absorbed by active transport, whereas TAQU was mostly absorbed by passive diffusion. Efflux transporters, P-glycoproteins, multidrug resistance proteins were proven to participate in the transport process of QU, but not in that of TAQU. These results suggested that improving the lipophicity of QU by esterification could increase the transport of QU across Caco-2 cells.

Lipozyme RM IM-catalyzed acidolysis of Cinnamomum camphora seed oil with oleic acid to produce human milk fat substitutes enriched in medium-chain fatty acids.

In the present study, a human milk fat substitute (HMFS) enriched in medium-chain fatty acids (MCFAs) was synthesized through acidolysis reaction from Cinnamomum camphora seed oil (CCSO) with oleic acid in a solvent-free system. A commercial immobilized lipase, Lipozyme RM IM, from Rhizomucor miehei, was facilitated as a biocatalyst. Effects of different reaction conditions, including substrate molar ratio, enzyme concentration, reaction temperature, and reaction time were investigated using response surface methodology (RSM) to obtain the optimal oleic acid incorporation. After optimization, results showed that the maximal incorporation of oleic acid into HMFS was 59.68%. Compared with CCSO, medium-chain fatty acids at the sn-2 position of HMFS accounted for >70%, whereas oleic acid was occupied predominantly at the sn-1,3 position (78.69%). Meanwhile, triacylglycerol (TAG) components of OCO (23.93%), CCO (14.94%), LaCO (13.58%), OLaO (12.66%), and OOO (11.13%) were determined as the major TAG species in HMFS. The final optimal reaction conditions were carried out as follows: substrate molar ratio (oleic acid/CCSO), 5:1; enzyme concentration, 12.5% (w/w total reactants); reaction temperature, 60 °C; and reaction time, 28 h. The reusability of Lipozyme RM IM in the acidolysis reaction was also evaluated, and it was found that it could be reused up to 9 times without significant loss of activities. Urea inclusion method was used to separate and purify the synthetic product. As the ratio of HMFS/urea increased to 1:2, the acid value lowered to the minimum. In a scale-up experiment, the contents of TAG and total tocopherols in HMFS (modified CCSO) were 77.28% and 12.27 mg/100 g, respectively. All of the physicochemical indices of purified product were within food standards. Therefore, such a MCFA-enriched HMFS produced by using the acidolysis method might have potential application in the infant formula industry.

Analysis of nonpolar lipophilic aldehydes/ketones in oxidized edible oils using HPLC-QqQ-MS for the evaluation of their parent fatty acids.

Six edible oils with different fatty acid compositions were used to explore nonpolar lipophilic aldehydes/ketones produced by possible parent fatty acids after accelerated oxidation. Simultaneous determination of 20 aldehydes and five ketones within the C2-C10 range was carried out using HPLC-QqQ-MS technique. Close relationships among the amounts of aldehyde carbonyls and the initial contents of oleic, linoleic and α-linolenic acids were revealed by principal component analysis. Pentanal, hexanal, hexanone, heptanal, 2-propenal, 2-heptenal, 2-octenal, 2-nonenal and 2,4-decadienal were the key carbonyls in close association with the initial content of linoleic acid. Ethanal, acetone, propanal, butanal, 2-pentenal, 2-hexenal, 2,4-heptadienal and 2,4-nonadienal were the key markers closely related with the initial content of α-linolenic acid. Furthermore, octanal, octanone, nonanal, nonanone, decanal, decanone and 2-decenal were the oxidation indexes linked to the initial content of oleic acid. The results provide a complete picture of secondary oxidation products in edible oils and possible source of parent fatty acids.