Gelation of Arabinoxylans from Maize Wastewater — Effect of Alkaline Hydrolysis Conditions on the Gel Rheology and Microstructure

The purpose of this research was to extract arabinoxylans (AX) from maize wastewater generated under different maize nixtamalization conditions and to investigate the polysaccharide gelling capability, as well as the rheological and microstructural characteristics of the gels formed. The nixtamalization conditions were 1.5 hours of cooking and 24 hours of alkaline hydrolysis (AX1) or 30 minutes cooking and 4 hours of alkaline hydrolysis (AX2). AX1 and AX2 presented yield values of 0.9% and 0.5% (w/v), respectively. Both AX samples presented similar molecular identity (Fourier Transform Infra-Red) and molecular weight distribution but different ferulic acid (FA) content. AX1 and AX2 presented gelling capability under laccase exposure. The kinetics of gelation of both AX samples was rheologically monitored by small amplitude oscillatory shear. The gelation profiles followed a characteristic kinetics with an initial increase in the storage modulus (G\u27) and loss modulus (G") followed by a plateau region for both gels. AX1 presented higher G\u27 than AX2. In scanning electron microscopy (SEM) images, both gels present an irregular honeycomb microstructure. The lower FA content in AX2 form gels presenting minor elasticity values and a more fragmented microstructure. These results indicate that nixtamalization process conditions can modify the characteristics of AX gels

Effect of Amidated Low-Methoxyl Pectin on Physicochemical Characteristics of Jumbo Squid (Dosidicus gigas) Mantle Muscle Gels

Proteini mišića Humboldtove lignje (Dosidicus gigas) imaju ograničenu primjenu u želatiniranim proizvodima zbog slabe funkcionalnosti. Svrha je ovoga rada bila ispitati utjecaj dodatka prirodnog, komercijalno dostupnog vlakna, i to amidiranog pektina s malim udjelom metoksila (0,5; 1,0; 1,5; 2,0 i 3,0 %), na fizikalno-kemijska i funkcionalna svojstva gelova dobivenih od plašta Humboldtove lignje (Dosidicus gigas). Dodatkom 0,5 % vlakana opažen je trenutni učinak na teksturu gela, i to na poboljšanje tvdoće (p<0,05) od (3,4±0,7) N u kontrolnom uzorku (bez dodatka vlakana) do (5,2±0,9) N, te elastičnosti (p≥0,05). Posmična sila bila je značajna samo pri dodatku 3,0 % vlakana. Dodatak vlakana također je poboljšao sposobnost vezivanja vode (p<0,05), i to sa 75 % u kontrolnom uzorku na 90-95 % na kraju pokusa. Dodatak od 3,0 % vlakana utjecao je na bjelinu. Diferencijalnom su motridbenom kalorimetrijom pronađena dva endotermna prijelaza u gelovima. Dodatak vlakana povećao je drugi pik (aktin) (p<0,05) za 1-2 ºC. Stoga je zaključeno da ispitivanje potvrđuje da je amidirani pektin s malim udjelom metoksila odličan dodatak za poboljšanje funkcionalnosti proteina mišića Humboldtove lignje, jer pozitivno utječe na teksturu dobivenih gelova i njihovu sposobnost zadržavanja vode.Jumbo squid (Dosidicus gigas) muscle proteins show low functionality with limited use in gel products. This work aims to assess the influence of adding the natural and commercially available fibre, amidated low-methoxyl pectin (at 0.5, 1.0, 1.5, 2.0 and 3.0 %), on the physicochemical and functional characteristics of jumbo squid (Dosidicus gigas) mantle muscle gels. The addition of 0.5 % fibre showed an immediate effect on the gel texture profile analysis, improving hardness (p<0.05) from (3.4±0.7) N of the control (no added fibre) to (5.2±0.9) N, and increasing elasticity (p≥0.05). Shear force was significant only at 3.0 % fibre addition. Water holding capacity also improved (p<0.05) with fibre addition (from 75 % in the control to 90–95 % aft er the treatments). Whiteness was affected (p<0.05) when 3.0 % fibre was added. Differential scanning calorimetry showed two endothermic transition peaks in the gels. The second peak (actin) increased (p<0.05) by 1–2 °C with fibre addition. Therefore, the present study demonstrates that amidated low-methoxyl pectin (0.5–3.0 %) is an excellent ingredient to improve jumbo squid mantle muscle protein functionality, increasing the gel texture and water retention characteristics

Pectin and Pectin-Based Composite Materials: Beyond Food Texture

Pectins are plant cell wall natural heteropolysaccharides composed mainly of &alpha;-1-4 d-galacturonic acid units, which may or may not be methyl esterified, possesses neutral sugars branching that harbor functional moieties. Physicochemical features as pH, temperature, ions concentration, and cosolute presence, affect directly the extraction yield and gelling capacity of pectins. The chemical and structural features of this polysaccharide enables its interaction with a wide range of molecules, a property that scientists profit from to form new composite matrices for target/controlled delivery of therapeutic molecules, genes or cells. Considered a prebiotic dietary fiber, pectins meetmany regulations easily, regarding health applications within the pharmaceutical industry as a raw material and as an agent for the prevention of cancer. Thus, this review lists many emergent pectin-based composite materials which will probably palliate the impact of obesity, diabetes and heart disease, aid to forestall actual epidemics, expand the ken of food additives and food products design

Efecto prebiótico de los Arabinoxilanos y los Arabinoxilo-Oligosacáridos y su relación con la promoción de la buena salud

Arabinoxylans are polysaccharides present in grains and as such, are part of dietary fiber intake in humans and animals. Enzymatic or chemical hydrolysis of arabinoxylans produces arabinoxilo-oligosaccharides, which can be branched or unbranched with arabinose. The objective of this work was to describe the potential use of arabinoxylans and arabinoxylan-oligosaccharides as prebiotics to promote good health, by selective enhancement of beneficial colonic microbiota growth and metabolic activity. The information generated indicates that arabinoxylans and arabinoxylan-oligosaccharides act by modifying the microbiota selectively and stimulate the biological response favoring good health in the host, by antio-obesity effect, glucose regulator, antioxidant, anticancer, immunomodulator, with similar or better results than recognized prebiotics. However, it is necessary to expand the knowledge we have about arabinoxylans in order to support their application in the food, pharmaceutical, and biomedical industry.Los arabinoxilanos son polisacáridos presentes en los granos de los cereales, y como tales, forman parte de la fibra dietética consumida por humanos y animales. La hidrólisis química o enzimática de los arabinoxilanos produce arabinoxilo-oligosacáridos, los cuales pueden estar ramificados o no, con arabinosa. El objetivo de este trabajo fue exponer el uso potencial de los arabinoxilanos y arabinoxilo-oligosacáridos, como prebióticos, y el efecto de su consumo en la promoción de la buena salud, al estimular selectivamente el crecimiento y actividad metabólica de la microbiótica colónica benéfica. La información generada indica que los arabinoxilanos y arabinoxilo-oligosacáridos actúan modificando la microbiota de manera selectiva, y estimulan la respuesta biológica, favoreciendo la buena salud del hospedero, por su efecto antiobesogénico, regulador de la glucosa, antioxidante, anticancerígeno e inmunomodulador, con resultados similares o mejores en relación a prebióticos reconocidos. No obstante, es necesario ampliar el conocimiento que se tiene de ellos para sustentar su aplicación en la industria alimentaria, farmacéutica o biomédica

Signaling of Plant Defense Mediated by Receptor-like Kinases, Receptor-like Cytoplasmic Protein Kinases and MAPKs Triggered by Fungal Chitin in Horticultural Crops

Fresh horticultural products are economically significant foods that are highly demanded by consumers worldwide; however, they are highly perishable and susceptible to deterioration by fungi, which contribute to their short shelf-life and cause significant post-harvest losses. Among the alternatives suggested for fungal control in plants is the elicitation of the innate plant defense mechanism, which may be activated when specific molecules of the phytopathogen, such as chitin, are recognized. Chitin is a long-chain polymer of N-acetyl-α-D-glucosamine of the fungal cell wall; it possesses biological activity by eliciting the plant immune response. This molecule and its oligosaccharides are recognized through transmembrane receptors known as receptor-like kinases (RLKs) and receptor-like proteins (RLPs). Mediated by receptor-like cytoplasmic kinases (RLCKs), which bind to the intracellular domain of these receptors, they initiate intracellular signal transduction via MAP kinases, triggering the plant defense response. In model plants, such as Oryza sativa (rice) and Arabidopsis thaliana, the set of RLK/RLP-RLCK-MAP kinases is involved in plant immunity triggered by chitin. Furthermore, in horticultural products, research into the molecular events between these three elements has suggested that similar processes occur. However, little is known about these molecular events in fruits. Against this background, the present review provides the most recent and relevant findings on the molecular associations of these three elements in the response to fungal chitin in plants and outlines which elements could participate in this signaling process in horticultural crops

Fermentation of Ferulated Arabinoxylan Recovered from the Maize Bioethanol Industry

International audienceMaize by-product from the bioethanol industry (distiller’s dried grains with solubles, DDGS) is a source of ferulated arabinoxylan (AX), which is a health-promoting polysaccharide. In the present study, AX from DDGS was fermented by a representative colonic bacterial mixture (Bifidobacterium longum, Bifidobacterium adolescentis, and Bacteroides ovatus), and the effect of the fermented AX (AX-f) on the proliferation of the cell line Caco-2 was investigated. AX was efficiently metabolized by these bacteria, as evidenced by a decrease in the polysaccharide molecular weight from 209 kDa to < 50 kDa in AX-f, the release of ferulic acid (FA) from polysaccharide chains (1.14 µg/mg AX-f), and the short-chain fatty acids (SCFA) production (277 µmol/50 mg AX). AX-f inhibited the proliferation of Caco-2 cells by 80–40% using concentrations from 125–1000 µg/mL. This dose-dependent inverse effect was attributed to the increased viscosity of the media due to the polysaccharide concentration. The results suggest that the AX-f dose range and the SCFA and free FA production are key determinants of antiproliferative activity. Using the same polysaccharide concentrations, non-fermented AX only inhibited the Caco-2 cells proliferation by 8%. These findings highlight the potential of AX recovered from the maize bioethanol industry as an antiproliferative agent once fermented by colonic bacteri

Maize bran gum: extraction, characterization and functional properties

Correspondance: [email protected] audienceA water-soluble maize bran gum (MBG) was alkali-extracted under mild conditions from maize bran. MBG presented an arabinoxylan (AX) content of 74% (w/w), a ferulic acid content of 0.34 mu g/mg MBG, an AIX ratio of 0.85 and an intrinsic viscosity of 208 ml/g. Gelling and emulsifying capabilities of MBG at different concentrations were investigated. Gels were obtained from this MBG by laccase covalent cross-linking of ferulic acid leading to the formation of diferulic (di-FA) and triferulic (tri-FA) acid. Gel hardness increased from 0.32 to 0.81 N as the MBG concentration changed from I to 2% (w/v) while the di-FA and tri-FA contents remained constant (0.030 and 0.015 mu g/mg MBG, respectively). The emulsion stability index (ESI) of oil-in-water containing different MBG concentrations was also investigated. ESI ranged from 0.01 to 0.20 as the MBG content in the mixture increased from 0% to 1% (w/v

Lycopene/Arabinoxylan Gels: Rheological and Controlled Release Characteristics

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