Formation of Strecker Aldehydes in Casein Digestion

Abstract Objectives This study investigated the occurrence of Strecker degradation during in vitro digestion. Methods Casein was first incubated with artificial gastric fluid containing porcine pepsin and HCl (pH = 2) for 60 min. After adjusting pH to 7 with sodium hydroxide, casein gastric digesta was then incubated with artificial intestinal fluid containing porcine pancreatin (pH = 7) for 120 min. Digesta samples were collected at 0, 10, 20, 30, and 60 min of gastric digestion, and then 10, 20, 30, 60, and 120 min of intestinal digestion. Free amino acids and aldehydes in digesta samples were analyzed by the liquid chromatography-mass spectrometry analysis. Results Multiple aldehydes were detected in gastric digestion samples, and their concentrations were further increased by intestinal digestion. Among them, isovaleraldehyde, isobutyraldehyde, phenylacetaldehyde, and acetaldehyde, are the Strecker degradation products of leucine, valine, phenylalanine, and alanine, respectively. Without digestive enzymes, casein incubation did not produce Strecker aldehydes. Conclusions In vitro digestion of proteins can produce Strecker aldehydes. Funding Sources This research was partially supported by the Agricultural Experiment Station project MIN-18-125 (C. C.) from the United States Department of Agriculture (USDA).

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Identification of Novel Surface Proteins of Anaplasma phagocytophilum by Affinity Purification and Proteomics

Journal of Bacteriology ◽

10.1128/jb.00866-07 ◽

2007 ◽

Vol 189 (21) ◽

pp. 7819-7828 ◽

Cited By ~ 45

Author(s):

Yan Ge ◽

Yasuko Rikihisa

Keyword(s):

Anaplasma Phagocytophilum ◽

Affinity Purification ◽

The United States ◽

Capillary Liquid Chromatography ◽

Etiologic Agent ◽

Surface Proteins ◽

Mass Spectrometry Analysis ◽

Spectrometry Analysis ◽

Major Surface

ABSTRACT Anaplasma phagocytophilum is the etiologic agent of human granulocytic anaplasmosis (HGA), one of the major tick-borne zoonoses in the United States. The surface of A. phagocytophilum plays a crucial role in subverting the hostile host cell environment. However, except for the P44/Msp2 outer membrane protein family, the surface components of A. phagocytophilum are largely unknown. To identify the major surface proteins of A. phagocytophilum, a membrane-impermeable, cleavable biotin reagent, sulfosuccinimidyl-2-[biotinamido]ethyl-1,3-dithiopropionate (Sulfo-NHS-SS-Biotin), was used to label intact bacteria. The biotinylated bacterial surface proteins were isolated by streptavidin agarose affinity purification and then separated by electrophoresis, followed by capillary liquid chromatography-nanospray tandem mass spectrometry analysis. Among the major proteins captured by affinity purification were five A. phagocytophilum proteins, Omp85, hypothetical proteins APH_0404 (designated Asp62) and APH_0405 (designated Asp55), P44 family proteins, and Omp-1A. The surface exposure of Asp62 and Asp55 was verified by immunofluorescence microscopy. Recombinant Asp62 and Asp55 proteins were recognized by an HGA patient serum. Anti-Asp62 and anti-Asp55 peptide sera partially neutralized A. phagocytophilum infection of HL-60 cells in vitro. We found that the Asp62 and Asp55 genes were cotranscribed and conserved among members of the family Anaplasmataceae. With the exception of P44-18, all of the proteins were newly revealed major surface-exposed proteins whose study should facilitate understanding the interaction between A. phagocytophilum and the host. These proteins may serve as targets for development of chemotherapy, diagnostics, and vaccines.

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Effect of In Vitro Digestion on Water-in-Oil-in-Water Emulsions Containing Anthocyanins from Grape Skin Powder

Molecules ◽

10.3390/molecules23112808 ◽

2018 ◽

Vol 23 (11) ◽

pp. 2808 ◽

Cited By ~ 3

Author(s):

Weili Xu ◽

Yang Yang ◽

Sophia Xue ◽

John Shi ◽

Loong-Tak Lim ◽

...

Keyword(s):

Small Intestine ◽

Encapsulation Efficiency ◽

In Vitro Digestion ◽

Gastric Digestion ◽

Grape Skin ◽

Double Emulsions ◽

Oil In Water ◽

Intestinal Digestion ◽

Droplet Sizes

The effects of in vitro batch digestion on water-in-oil-in-water (W/O/W) double emulsions encapsulated with anthocyanins (ACNs) from grape skin were investigated. The double emulsions exhibited the monomodal distribution (d = 686 ± 25 nm) showing relatively high encapsulation efficiency (87.74 ± 3.12%). After in vitro mouth digestion, the droplet size (d = 771 ± 26 nm) was significantly increased (p < 0.05). The double W1/O/W2 emulsions became a single W1/O emulsion due to proteolysis, which were coalesced together to form big particles with significant increases (p < 0.01) of average droplet sizes (d > 5 µm) after gastric digestion. During intestinal digestion, W1/O droplets were broken to give empty oil droplets and released ACNs in inner water phase, and the average droplet sizes (d < 260 nm) decreased significantly (p < 0.05). Our results indicated that ACNs were effectively protected by W/O/W double emulsions against in vitro mouth digestion and gastric, and were delivered in the simulated small intestine phase.

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Antioxidant indices and amino acid composition of phenolic containing Lima beans (Phaseolus lunatus) after simulated human gastrointestinal digestion

International Journal of Food Studies ◽

10.7455/ijfs.v8i1.593 ◽

2019 ◽

Vol 8 (1) ◽

Author(s):

Sule O. Salawu ◽

Oluwaseun M. Folorunso ◽

Akintunde A. Akindahunsi ◽

Aline A. Boligon

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

In Vitro Digestion ◽

Phaseolus Lunatus ◽

Gastric Digestion ◽

Antioxidant Power ◽

Intestinal Digestion ◽

Lima Beans

The present investigation was designed to characterize the phenolic profile of Lima beans (Phaseolus Lunatus) and also to evaluate the antioxidant indices: total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and amino acid composition at different stages of simulated gastrointestinal digestion (oral, gastric, intestinal). High Performance Liquid Chromatography (HPLC-DAD) analysis revealed the presence of some phenolic compounds (gallic acid, catechin, caffeic acid, rutin, quercitrin, quercetin, kaempferol and apigenin), with a reduced amount (mg/g) after cooking; gallic acid (raw: 1.96 ± 0.02; cooked: 1.82 ± 0.01); catechin (raw: 0.83 ± 0.01; cooked: 0.73 ± 0.01); rutin (raw: 2.61 ± 0.03; cooked:1.74 ±0.03); quercitrin (raw: 5.73 ± 0.01; cooked: 5.68 ± 0.01); apigenin (raw: 2.09 ±0.01; cooked:1.79 ± 0.02), with exception of quercetin (raw: 2.11 ±0.02; cooked: 5.73 ± 0.02) and caffeic acid (raw: 2.08 ±0.04; cooked: 2.95 ± 0.04). The results of antioxidant indices of in vitro enzyme digested lima beans revealed higher values for cooked Lima beans compared to the raw counterpart, with a stepwise increase at the different stages of in vitro digestion, with the exception of ferric reducing antioxidant power; TPC (oral digestion: 65.44 ± 0.96; gastric digestion:134.87± 0.46; intestinal digestion:517.72 ± 4.70; mg/g tannic acid equivalent), TFC (oral digestion: 199.30 ± 6.43; gastric digestion: 1065.97 ± 1.22; intestinal digestion: 3691.87 ± 4.2; mg/g quercetin equivalent), DPPH (oral digestion: 85800.00 ± 305.50; gastric digestion: 99066.66 ± 115.47; intestinal digestion: 211354.20 ± 360.84 µmol TE/g sample). The results also revealed a progressive increase in the antioxidant indices and amino acid composition (mg/kg) for both raw and processed lima beans at various stages of the in vitro digestion, with the intestinal phase of simulated digestion ranking higher. This implied that the Lima beans contained some essential amino acids and antioxidant molecules that would be readily available after passing through the gastrointestinal tract and could therefore be explored as functional food in the management of free radical mediated diseases.

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Coating oil droplets with rice proteins to control the release rate of encapsulated beta-carotene during in vitro digestion

RSC Advances ◽

10.1039/c6ra14943j ◽

2016 ◽

Vol 6 (77) ◽

pp. 73627-73635 ◽

Cited By ~ 10

Author(s):

Tao Wang ◽

Ren Wang ◽

Zhengxing Chen ◽

Qixin Zhong

Keyword(s):

Release Rate ◽

Beta Carotene ◽

In Vitro Digestion ◽

Gastric Digestion ◽

Oil Droplets ◽

Intestinal Digestion ◽

Β Carotene

The release of encapsulated β-carotene is limited in simulated gastric digestion and is controllable in simulated intestinal digestion.

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Phytochemicals of Minthostachys diffusa Epling and Their Health-Promoting Bioactivities

Foods ◽

10.3390/foods9020144 ◽

2020 ◽

Vol 9 (2) ◽

pp. 144

Author(s):

Immacolata Faraone ◽

Daniela Russo ◽

Lucia Chiummiento ◽

Eloy Fernandez ◽

Alka Choudhary ◽

...

Keyword(s):

Ethyl Acetate ◽

Radical Scavenging ◽

Ethyl Acetate Fraction ◽

Mass Spectrometry Analysis ◽

Antioxidant Power ◽

Spectrometry Analysis ◽

In Silico Docking ◽

Aerial Parts ◽

Health Promoting

The genus Minthostachys belonging to the Lamiaceae family, and is an important South American mint genus used commonly in folk medicine as an aroma in cooking. The phytochemical-rich samples of the aerial parts of Minthostachys diffusa Epling. were tested for pharmacological and health-promoting bioactivities using in vitro chemical and enzymatic assays. A range of radical scavenging activities of the samples against biological radicals such as nitric oxide and superoxide anion and against synthetic 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, the ferric reducing antioxidant power and the lipid peroxidation inhibition were determined and ranked using the ‘relative antioxidant capacity index’ (RACI). The ethyl acetate fraction showed the highest RACI of +1.12. Analysis of the various fractions’ inhibitory ability against enzymes involved in diabetes (α-amylase and α-glucosidase), and against enzymes associated with Parkinson’s or Alzheimer’s diseases (acetylcholinesterase and butyrylcholinesterase) also suggested that the ethyl acetate fraction was the most active. Liquid chromatography–tandem mass spectrometry analysis of the ethyl acetate fraction showed more than 30 polyphenolic compounds, including triterpenes. The inhibitory cholinesterase effects of the triterpenes identified from M. diffusa were further analysed by in silico docking of these compounds into 3D-structures of acetylcholinesterase and butyrylcholinesterase. This is the first study on pharmacological activities and phytochemical profiling of the aerial parts of M. diffusa, showing that this plant, normally used as food in South America, is also rich in health-promoting phytochemicals.

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Impact of the Simulated Gastric Digestion Methodology on the In Vitro Intestinal Proteolysis and Lipolysis of Emulsion Gels

Foods ◽

10.3390/foods10020321 ◽

2021 ◽

Vol 10 (2) ◽

pp. 321

Author(s):

Camila Mella ◽

Michelle Quilaqueo ◽

Rommy N. Zúñiga ◽

Elizabeth Troncoso

Keyword(s):

Heat Treatment ◽

Protein Isolate ◽

Gastric Digestion ◽

Human Gastrointestinal Tract ◽

Gel Structure ◽

Intestinal Digestion ◽

Food Digestion ◽

The Impact ◽

Digestion Methods

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.

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A Comparative Study of the Antioxidative Effects of Helichrysum italicum and Helichrysum arenarium Infusions

Antioxidants ◽

10.3390/antiox10030380 ◽

2021 ◽

Vol 10 (3) ◽

pp. 380

Author(s):

Katja Kramberger ◽

Zala Jenko Pražnikar ◽

Alenka Baruca Arbeiter ◽

Ana Petelin ◽

Dunja Bandelj ◽

...

Keyword(s):

Oxidative Stress ◽

High Performance ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Morphological Type ◽

Mass Spectrometry Analysis ◽

In Vitro Assays ◽

Spectrometry Analysis ◽

Stress Related Genes

Helichrysum arenarium (L.) Moench (abbrev. as HA) has a long tradition in European ethnomedicine and its inflorescences are approved as a herbal medicinal product. In the Mediterranean part of Europe, Helichrysum italicum (Roth) G. Don (abbrev. as HI) is more common. Since infusions from both plants are traditionally used, we aimed to compare their antioxidative potential using in vitro assays. Two morphologically distinct HI plants, HIa and HIb, were compared to a commercially available HA product. Genetic analysis using microsatellites confirmed a clear differentiation between HI and HA and suggested that HIb was a hybrid resulting from spontaneous hybridization from unknown HI subspecies. High-performance liquid chromatography–mass spectrometry analysis showed the highest amounts of hydroxycinnamic acids and total arzanol derivatives in HIa, whereas HIb was richest in monohydroxybenzoic acids, caffeic acids, and coumarins, and HA contained the highest amounts of flavonoids, especially flavanones. HIa exhibited the highest radical scavenging activity; it was more efficient in protecting different cell lines from induced oxidative stress and in inducing oxidative stress-related genes superoxide dismutase 1, catalase, and glutathione reductase 1. The antioxidative potential of HI was not only dependent on the morphological type of the plant but also on the harvest date, revealing important information for obtaining the best possible product. Considering the superior properties of HI compared to HA, the evaluation of HI as a medicinal plant could be recommended.

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Monitoring the extraction of additives and additive degradation products from polymer packaging into solutions by multi-residue method including solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-013-7551-4 ◽

2013 ◽

Vol 406 (5) ◽

pp. 1493-1507 ◽

Cited By ~ 20

Author(s):

Charlène Pouech ◽

Florent Lafay ◽

Laure Wiest ◽

Robert Baudot ◽

Didier Léonard ◽

...

Keyword(s):

High Performance ◽

Solid Phase ◽

Degradation Products ◽

Mass Spectrometry Analysis ◽

Tandem Mass ◽

Spectrometry Analysis ◽

Tandem Mass Spectrometry Analysis ◽

Chromatography Tandem Mass Spectrometry ◽

Additive Degradation ◽

Liquid Chromatography Tandem Mass

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Phytotoxicity of Essential Oils on Selected Weeds: Potential Hazard on Food Crops

Plants ◽

10.3390/plants7040079 ◽

2018 ◽

Vol 7 (4) ◽

pp. 79 ◽

Cited By ~ 12

Author(s):

María Ibáñez ◽

María Blázquez

Keyword(s):

Seed Germination ◽

Essential Oil ◽

Essential Oils ◽

Mass Spectrometry Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Food Crops ◽

Potential Hazard ◽

Spectrometry Analysis

The chemical composition of winter savory, peppermint, and anise essential oils, and in vitro and in vivo phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, and Echinochloa crus-galli) and food crops (maize, rice, and tomato), have been studied. Sixty-four compounds accounting for between 97.67–99.66% of the total essential oils were identified by Gas Chromatography-Mass Spectrometry analysis. Winter savory with carvacrol (43.34%) and thymol (23.20%) as the main compounds produced a total inhibitory effect against the seed germination of tested weed. Menthol (48.23%), menthone (23.33%), and iso-menthone (16.33%) from peppermint only showed total seed germination inhibition on L. multiflorum, whereas no significant effects were observed with trans-anethole (99.46%) from anise at all concentrations (0.125–1 µL/mL). Low doses of peppermint essential oil could be used as a sustainable alternative to synthetic agrochemicals to control L. multiflorum. The results corroborate that in vivo assays with a commercial emulsifiable concentrate need higher doses of the essential oils to reproduce previous in vitro trials. The higher in vivo phytotoxicity of winter savory essential oil constitutes an eco-friendly and less pernicious alternative to weed control. It is possible to achieve a greater in vivo phytotoxicity if less active essential oil like peppermint is included with other active excipients.

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