不同提取工艺对茶树菇多糖得率及抗脂质过氧化作用的影响

采用水提醇沉法提取茶树菇多糖,设计单因素试验和正交试验以探讨提取温度、pH值和细胞破碎方式等因素对茶树菇多糖得率及抗脂质过氧化能力的影响.从而优化茶树菇多糖的提取工艺.正交试验结果表明:最佳理论提取工艺条件:温度为80℃,pH值为7.5,细胞破碎方式为冻融3次;最佳直观分析提取工艺:温度为80℃,pH值为7.5,细胞破碎方式为超声波30 min.验证试验结果表明,二者差异不显著.考虑到成本、能耗等问题最终确定最佳提取工艺为温度为80℃,pH值为7.5,细胞破碎方式为超声波30min.     

In Vitro Bioactivity of Astaxanthin and Peptides from Hydrolisates of Shrimp (Parapenaeus longirostris) By-Products: From the Extraction Process to Biological Effect Evaluation,as Pilot Actions for the Strategy “From Waste to Profit”

Non-edible parts of crustaceans could be a rich source of valuable bioactive compounds such as the carotenoid astaxanthin and peptides, which have well-recognized beneficial effects. These compounds are widely used in nutraceuticals and pharmaceuticals, and their market is rapidly growing, suggesting the need to find alternative sources. The aim of this work was to set up a pilot-scale protocol for the reutilization of by-products of processed shrimp, in order to address the utilization of this valuable biomass for nutraceutical and pharmaceuticals application, through the extraction of astaxanthin-enriched oil and antioxidant-rich protein hydrolysates. Astaxanthin (AST) was obtained using “green extraction methods,” such as using fish oil and different fatty acid ethyl esters as solvents and through supercritical fluid extraction (SFE), whereas bioactive peptides were obtained by protease hydrolysis. Both astaxanthin and bioactive peptides exhibited bioactive properties in vitro in cellular model systems, such as antioxidant and angiotensin I converting enzyme (ACE) inhibitory activities (IA). The results show higher astaxanthin yields in ethyl esters fatty acids (TFA) extraction and significant enrichment by short-path distillation (SPD) up to 114.80 ± 1.23 µg/mL. Peptide fractions of <3 kDa and 3–5 kDa exhibited greater antioxidant activity while the fraction 5–10 kDa exhibited a better ACE-IA. Lower-molecular-weight bioactive peptides and astaxanthin extracted using supercritical fluids showed protective effects against oxidative damage in 142BR and in 3T3 cell lines. These results suggest that “green” extraction methods allow us to obtain high-quality bioactive compounds from large volumes of shrimp waste for nutraceutical and pharmaceutical applications.     

Sunflower Protein Hydrolysates Reduce Cholesterol Micellar Solubility

Plant protein hydrolysates are a source of bioactive peptides. There are peptides that decrease the micellar cholesterol solubility from bile acids and therefore may reduce in vivo cholesterol absorption. The presence of these peptides in sunflower protein hydrolysates has been studied. Sunflower protein hydrolysates produced with alcalase plus flavourzyme or with pepsin plus pancreatin inhibited in some degree the cholesterol incorporation to micelles. Protein hydrolysates generated after 30 min of hydrolysis with alcalase, and after 30 min of hydrolysis with pepsin, were the inhibitoriest of the cholesterol incorporation to micelles. The average amino acid hydrophobicity of inhibitory peptides in cholesterol micelles was higher than the observed in the corresponding protein hydrolysates. This high hydrophobicity probably favours their inclusion in the lipid micelles. In vivo, this inhibition may translate in a decrease of cholesterol absorption. Reported results show that a combination of different characteristics such as peptide size or hydrophobicity may be responsible of the inhibitory activity of generated peptides.     

茶多糖生物活性及提取纯化的研究进展

茶多糖是一种碳水化合物聚合体，具有降血糖、降血脂、提高机体免疫力、抗凝血、抗血栓、耐缺氧、抗紫外线、杭X射线辐射等一系列特殊保健功能。本文综述了茶多糖的组成、结构、多种特殊功能和茶多糖的提取纯化及其应用。     

Peptides from Chia Present Antibacterial Activity and Inhibit Cholesterol Synthesis

In previous studies, it has not been reported that protein isolated from chia interferes favorably with antibacterial activity, and reduces cholesterol synthesis. The objective of this study was to determine whether commonly used commercial microbial proteases can be utilized to generate chia protein-based antibacterial and hypocholesterolemic hydrolysates/peptides, considering the effects of protein extraction method. Alcalase, Flavourzyme and sequential Alcalase-Flavourzyme were used to produce hydrolysates from chia protein (CF), protein-rich fraction (PRF) and chia protein concentrates (CPC1 and CPC2). These hydrolysates were evaluated for their antimicrobial activity against Gram-positive (G⁺) and Gram-negative (G^?) microorganisms. The protein hydrolysates were purified by ultrafiltration through a membrane with 3 kDa nominal molecular weight, for evaluation of hypocholesterolemic activity. An inhibition zone was observed when the hydrolysate was tested against S. aureus, and minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were obtained. Peptides from chia protein with molecular mass lower than 3 kDa reduced up to 80.7% of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) enzymatic reaction velocity. It was also observed that, independent of the method used to obtain chia proteins, the fractions showed relevant bioactivity. Moreover, the intensity of the bioactivity varied with the method for obtaining the protein and with the enzyme used in the hydrolysis process. This is the first report to demonstrate that chia peptides are able to inhibit cholesterol homeostasis.     

“Antioxidant activity and characterization of protein fractions and hydrolysates from normal and quality protein maize kernels”

Maize is the main crop cultivated worldwide with more than 1 billion metric tons produced annually and is one of the most relevant sources of protein for human consumption in developing countries. Proteins and peptides isolated from maize exert relevant antioxidant activity which is increased by enzymatic hydrolysis. However, there is limited information about the antioxidant potential of proteins isolated from Quality Protein Maize (QPM) varieties and their hydrolysates. The aim of this research was to determine the differences in protein profile and antioxidant activity of protein fractions and hydrolysates between a hybrid white maize (Asgrow 773) and a QPM variety (CML-502). The biophysical evaluation and the total protein quantification by Kjeldahl and fractions by ninhydrin were consistent with the changes due to the breeding process of the QPM material. The antioxidant potential of the hydrolysates obtained from albumins and globulins had a 3-fold increase in both maize varieties. The prolamins hydrolysates presented an increase of 7-fold for the normal variety and 2-fold for the QPM variety. The results of this research allow indicate that the QPM varieties are a source of antioxidant peptides and promising candidates in the search for proteins and peptides with other bioactivities.     

Amino Acid Profiles and Biopotentiality of Hydrolysates Obtained from Comb Penshell (Atrina pectinata) Viscera Using Subcritical Water Hydrolysis

The recovery of amino acids and other important bioactive compounds from the comb penshell (Atrina pectinata) using subcritical water hydrolysis was performed. A wide range of extraction temperatures from 140 to 290 °C was used to evaluate the release of proteins and amino acids. The amount of crude protein was the highest (36.14 ± 1.39 mg bovine serum albumin/g) at 200 °C, whereas a further increase in temperature showed the degradation of the crude protein content. The highest amount of amino acids (74.80 mg/g) was at 230 °C, indicating that the temperature range of 170–230 °C is suitable for the extraction of protein-rich compounds using subcritical water hydrolysis. Molecular weights of the peptides obtained from comb penshell viscera decreased with the increasing temperature. SDS-PAGE revealed that the molecular weight of peptides present in the hydrolysates above the 200 °C extraction temperature was ≤ 1000 Da. Radical scavenging activities were analyzed to evaluate the antioxidant activities of the hydrolysates. A. pectinata hydrolysates also showed a particularly good antihypertensive activity, proving that this raw material can be an effective source of amino acids and marine bioactive peptides.     

Minor components and wheat quality: Perspectives on climate changes

Minor compounds of cereal grains such as lipids and cell wall polysaccharides play an important role in their milling properties, their transformation into baked cereal products and their nutritional properties. These effects are mainly due to their interactive properties, such as their ability to absorb large amounts of water for polysaccharides or to interact with starch polymers and proteins for lipids. Environmental stress induced by climate change and regulations for environmentally friendly agriculture can interfere with the biosynthesis of these minor grain compounds as well as the main compounds starch and protein. Indeed, the metabolic networks of all components of the endosperm of grains are closely associated. Therefore, in the context of climate change and agricultural sustainability, lipids and cell wall polysaccharides may be affected. Contrasting with a plethora of studies reporting the impact of environment and fertilizer on cereal proteins, there is a real lack of information on this particular topic for these minor compounds. However, our knowledge of the physico-chemical properties and biosynthesis of these minor compounds allows us to assess the likely strong impact of environmental and agronomic constraints on the relationships between cell wall polysaccharides, lipids and cereal quality.     

Multifunctional bioactive peptides derived from quinoa protein hydrolysates: Inhibition of α-glucosidase,dipeptidyl peptidase-IV and angiotensin I converting enzymes

The study aimed to characterize and identify anti-diabetic and anti-hypertensive bioactive peptides generated upon enzymatic hydrolysis of quinoa protein isolates. Different quinoa protein hydrolysates (QPHs) were produced using food grade enzymes like Bromelain, chymotrypsin and Pronase E at a hydrolysis interval of 2 h up to 6 h. QPHs were characterized for their physicochemical properties using degree of hydrolysis, SDS-PAGE, and their anti-diabetic properties via inhibition of dipeptidyl peptidase-IV (DPP-IV) and α-glucosidase (AG), and anti-hypertensive property via inhibition of angiotensin converting enzyme (ACE) were explored. IC₅₀ for DPP-IV, AG and ACE inhibitory activities of QPHs were in the range of 0.72–1.12, 1.00–1.86 and 0.18–0.31 mg/mL, respectively. The chymotrypsin derived 6 h hydrolysate (QC6) was sequenced for peptides identification and 136 peptides were identified among which 35 peptides were predicted as potential bio-active peptides (BAPs) based on their Peptide Ranker score. Results showed that identified peptides were predicted to possess high potential in inhibiting the DPP-IV, AG and ACE. In particular, QHPHGLGALCAAPPST was found to bind to the highest number of active hotspots of the target enzymes that are involved in their enzymatic activities. In conclusion, quinoa protein hydrolysates were identified as potential sources of BAPs with inhibitory properties towards key enzymes involved in the control of type 2 diabetes and hypertension.     

Proteins in Walls of Wheat Aleurone Cells

The protein content (1% w/w) of purified walls from aleurone layers is twice that of walls from the starchy endosperm but their amino acid compositions are comparable. Aprotic solvent extraction and specific enzymatic and chemical degradation of wall polysaccharides released some proteins, and treatment with specific proteases released peptides. The aleurone wall residue (18% of the original wall) after (1→3,1→4)-β-glucan and xylan hydrolase digestion contains 4·5% (w/w) protein associated with cellulosic glucan, glucomannan and highly-substituted arabinoxylan and remains autofluorescent. Wall residues after treatment with 1 M sodium hydroxide also remain autofluorescent indicating they retain a significant proportion of their original 1·84% (w/w) of hydroxycinnamic acids and that these are not exclusively attached to the wall polymers by ester linkages. Little protein was extracted from the walls using non-degradative solvents. However, significant quantities were recovered from whole walls and xylanase-treated wall residues by SDS/mercaptoethanol extraction and electroelution. The various protein fractions isolated were characterised by their amino acid compositions and, in some cases, by amino acid sequencing. Three classes of proteins were identified in wall fractions or from proteolysis fragments: glycine-rich proteins (37–86%), proline-rich proteins (11–39%) and proteins with up to 23% serine. Protein-polysaccharide cross-linking through tyrosine-hydroxycinnamic acid dimerisation may be responsible for the alkali-resistant autofluorescence and the insolubility of the protein may be due, in part, to cross-linking through tyrosine-tyrosine bridges. These associations may also contribute to the relative resistance of the inner aleurone wall layer to enzymic dissolution during germination.     

Marine Ingredients for Sensitive Skin: Market Overview

Marine ingredients are a source of new chemical entities with biological action, which is the reason why they have gained relevance in the cosmetic industry. The facial care category is the most relevant in this industry, and within it, the sensitive skin segment occupies a prominent position. This work analyzed the use of marine ingredients in 88 facial cosmetics for sensitive skin from multinational brands, as well as their composition and the scientific evidence that supports their efficacy. Marine ingredients were used in 27% of the cosmetic products for sensitive skin and included the species Laminaria ochroleuca, Ascophyllum nodosum (brown macroalgae), Asparagopsis armata (red macroalgae), and Chlorella vulgaris (microalgae). Carotenoids, polysaccharides, and lipids are the chemical classes highlighted in these preparations. Two ingredients, namely the Ascophyllum nodosum extract and Asparagopsis armata extracts, present clinical evidence supporting their use for sensitive skin. Overall, marine ingredients used in cosmetics for sensitive skin are proposed to reduce skin inflammation and improve the barrier function. Marine-derived preparations constitute promising active ingredients for sensitive skin cosmetic products. Their in-depth study, focusing on the extracted metabolites, randomized placebo-controlled studies including volunteers with sensitive skin, and the use of extraction methods that are more profitable may provide a great opportunity for the cosmetic industry.     

Proteins and Carbohydrates from Red Seaweeds: Evidence for Beneficial Effects on Gut Function and Microbiota

Based on their composition, marine algae, and namely red seaweeds, are good potential functional foods. Intestinal mucosal barrier function refers to the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules. Here, we will first outline the component of seaweeds and will summarize the effects of these on the regulation of mucosal barrier function. Special attention will be paid to unique components of red seaweeds: proteins and derived peptides (e.g., phycobiliproteins, glycoproteins that contain “cellulose binding domains”, phycolectins and the related mycosporine-like amino acids) together with polysaccharides (e.g., floridean starch and sulfated galactans, such as carrageenans, agarans and “dl-hybrid”) and minerals. These compounds have been shown to exert prebiotic effects, to regulate intestinal epithelial cell, macrophage and lymphocyte proliferation and differentiation and to modulate the immune response. Molecular mechanisms of action of peptides and polysaccharides are starting to be elucidated, and evidence indicating the involvement of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), Toll-like receptors (TLR) and signal transduction pathways mediated by protein kinase B (PKB or AKT), nuclear factor-κB (NF-κB) and mitogen activated protein kinases (MAPK) will also be summarized. The need for further research is clear, but in vivo experiments point to an overall antiinflammatory effect of these algae, indicating that they can reinforce membrane barrier function.     

Chemical structures and bioactivities of sulfated polysaccharides from marine algae

Sulfated polysaccharides and their lower molecular weight oligosaccharide derivatives from marine macroalgae have been shown to possess a variety of biological activities. The present paper will review the recent progress in research on the structural chemistry and the bioactivities of these marine algal biomaterials. In particular, it will provide an update on the structural chemistry of the major sulfated polysaccharides synthesized by seaweeds including the galactans (e.g., agarans and carrageenans), ulvans, and fucans. It will then review the recent findings on the anticoagulant/antithrombotic, antiviral, immuno-inflammatory, antilipidemic and antioxidant activities of sulfated polysaccharides and their potential for therapeutic application.     

酶法制备大豆降血压肽的研究进展

研究表明大豆蛋白酶解物具有降血压的功能,本文综述了国内外酶法制备大豆降血压肽的研究现状,指出了目前研究中存在的一些问题,并展望了大豆降压血肽的应用前景.     

The contribution of different groups of foodstuffs to the intake of dietary fibre

The intake of Dietary Fibre (which is defined as the sum of lignin and the polysaccharides not hydrolysed by the endogenous secretions of the human digestive tract) is derived from the plant cell walls in the diet and other non-structural polysaccharides either present naturally in foods, or derived from polysaccharide food additives such as gums or algal polysaccharides. The composition of this complex mixture, its chemical and physical properties, and therefore, the physiological effects associated with its ingestion, will vary according to the foods making up in the diet. While techniques for the measurement and characterisation of dietary fibre still call for a considerable amount of methodological development it is possible to obtain reliable estimates for the major components and the overall composition of these components. These show that in fruits and vegetables the total dietary fibre content (on a fresh weight basis) lies between 2 and 5 g/100 g with peas and beans being an exception in having higher contents. The dietary fibre in cereals varies with the cereal and the reate of extraction used; for example, wholemeal wheat flours contain between 12 and 15 g/100 g whereas white wheat flour (72% extraction) contains between 3 and 4 g/100 g. Wheat bran and related products have much higher contents. The proportion of the dietary fibre present as cellulose does not show great variablility but lignin is extremely variable. Fruits and vegetables contain very small amounts of lignin unless they have lignified seeds or special lignified tissues. The non-cellulosic polysaccharides of fruits and vegetables are characteristically rich in uronic acids (from pectic substances) and arabino-galactans. In cereals β-glucans and arabino-xylans predominate and wheat bran and wholemeal wheat and rye flours are particularly rich in arabino-xylans. The amounds and composition of the dietary fibre in foods commonly forming the diet eaten in the United Kingdom will be reviewed and their contribution to the diet as a whole will be discussed. Changes in the pattern of food consumption in the United Kingdom in the past century will be discussed in relation to the effects that these have had on the consumption of dietary fibre.     

Biofunctionality of Enzymatically Derived Peptides from Codfish (Gadus morhua) Frame: Bulk In Vitro Properties,Quantitative Proteomics,and Bioinformatic Prediction

Protein hydrolysates show great promise as bioactive food and feed ingredients and for valorization of side-streams from e.g., the fish processing industry. We present a novel approach for hydrolysate characterization that utilizes proteomics data for calculation of weighted mean peptide properties (length, molecular weight, and charge) and peptide-level abundance estimation. Using a novel bioinformatic approach for subsequent prediction of biofunctional properties of identified peptides, we are able to provide an unprecedented, in-depth characterization. The study further characterizes bulk emulsifying, foaming, and in vitro antioxidative properties of enzymatic hydrolysates derived from cod frame by application of Alcalase and Neutrase, individually and sequentially, as well as the influence of heat pre-treatment. All hydrolysates displayed comparable or higher emulsifying activity and stability than sodium caseinate. Heat-treatment significantly increased stability but showed a negative effect on the activity and degree of hydrolysis. Lower degrees of hydrolysis resulted in significantly higher chelating activity, while the opposite was observed for radical scavenging activity. Combining peptide abundance with bioinformatic prediction, we identified several peptides that are likely linked to the observed differences in bulk emulsifying properties. The study highlights the prospects of applying proteomics and bioinformatics for hydrolysate characterization and in food protein science.     

Seaweed polysaccharides and derived oligosaccharides stimulate defense responses and protection against pathogens in plants

Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.     

Bioactive peptides and depsipeptides with anticancer potential: sources from marine animals

Biologically active compounds with different modes of action, such as, antiproliferative, antioxidant, antimicrotubule, have been isolated from marine sources, specifically algae and cyanobacteria. Recently research has been focused on peptides from marine animal sources, since they have been found as secondary metabolites from sponges, ascidians, tunicates, and mollusks. The structural characteristics of these peptides include various unusual amino acid residues which may be responsible for their bioactivity. Moreover, protein hydrolysates formed by the enzymatic digestion of aquatic and marine by-products are an important source of bioactive peptides. Purified peptides from these sources have been shown to have antioxidant activity and cytotoxic effect on several human cancer cell lines such as HeLa, AGS, and DLD-1. These characteristics imply that the use of peptides from marine sources has potential for the prevention and treatment of cancer, and that they might also be useful as molecular models in anticancer drug research. This review focuses on the latest studies and critical research in this field, and evidences the immense potential of marine animals as bioactive peptide sources.     

Food grade oilseed protein processing: sunflower and rapeseed

Industrial sunflower and rapeseed meals cannot be directly used as a food because of their high fiber content and because of the presence of some undesirable constituents (such as hulls, polyphenolic pigments, etc.) or precursors of toxic compounds (glucosinolates, etc.). Edible protein products (flours, concentrates, and isolates) from these two sources can be obtained by carrying out, to various degrees, and with different procedures, extraction operations of non-proteic and potentially toxic or antinutritional components. All the possible combinations of the single extraction operations (removal of fiber, lipids, polysaccharides, etc.) were studied by various authors in order to develop an optimum process both from the economic and the product quality points of view.In this report the problems related to the individual extraction operations, rather than to individual processes, are reviewed for reasons of recapitulation and to provide a common basis for comparison. Although it is impossible to reach a definitive conclusion it appears that some of the processes reviewed are able to produce very attractive raw materials for food manufacturing industries. Nevertheless, no food grade sunflower or rapeseed proteins have appeared on the market to date. However, sunflower and rapeseed protein sources will have to be taken into account in the near future as an added promising means for attacking food shortage problems.     

An improved method for extraction of sorghum polymeric protein complexes

A method for fractionating sorghum proteins using extraction solvents and techniques designed to obtain polymeric protein structures (especially disulfide linked) was developed. Extraction and separation conditions were optimized in terms of completeness of protein extraction, sample stability, and analytical resolution. After pre-extraction of albumins and globulins, a 3-step sequential procedure involving no reducing agents was applied to ground whole sorghum flour. The three fractions obtained represented proportionally different protein polymer contents and molecular weight distribution as evidenced by comparative size exclusion chromatography. Protein composition also varied among the extracts with differences in kafirin composition and non-kafirin proteins detected in the fractions by RP-HPLC and SDS-PAGE analysis. The ability to quantify and further characterize sorghum polymeric protein complexes will be useful for additional studies linking protein structures with functionality and digestibility and variations for these properties within diverse sorghum germplasm.