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Tomato is one of the most commercialised and consumed fruits worldwide. However, tomatoes are highly susceptible to Alternaria rot. Among the safe strategies proposed to control Alternaria rot is the induction of defence mechanisms through biological elicitors, such as chitin. Chitin and its oligosaccharides are an activate plant defence mechanisms, but studies of fruits exposed to fungal chitin fragments are scarce. Therefore, the present work aimed to obtain and partially characterise chitin oligomers of Alternaria alternata, and evaluate their effect on the defence mechanism of tomato fruits and their tolerance to Alternaria rot. The chitin oligomers obtained had a molecular weight of ≤ 1 kDa, 12% N-acetyl-glucosamine, 0.2% residual protein, and were 94% acetylated. These oligomers markedly increased the enzymatic activity of chitinase and β-1,3-glucanase in tomato fruits, and the development of Alternaria rot was inhibited by 78%. Chitin oligomers of A. alternata represent a promising alternative to attenuate Alternaria rot in tomato fruits through an enzymatic defence mechanism. [ABSTRACT FROM AUTHOR]

The processes to obtain value-added products from brewers' spent grain, a contaminant industrial waste, require alkaline non-ecofriendly pre-treatments. The arabinoxylans from brewers' spent grain were extracted by nixtamalization evaluating the extraction procedure, antioxidant capacity and molecular characteristics. The best arabinoxylans yields were those extracted with CaO at 100 °C and 25 °C (6.43% and 3.37%, respectively). The antioxidant capacity by 2,2-diphenyl-1-picrylhydrazyl assay of the arabinoxylans after thermal treatment and additional arabinoxylans after thermal treatment proteolysis were 434 and 118 mg TE/g, while by 2,20'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt assay the value was similar (380 μmol TE/g). The intrinsic viscosities and viscosimetric molecular weights were 69 mL/g and 13 kDa for arabinoxylans after thermal treatment, and 15 mL/g and 1.6 kDa for arabinoxylans after thermal treatment proteolysis, respectively. The protein and lignin contents were 3.1% and 6.4% for arabinoxylans after thermal treatment and, 0.9% and 4.6% for arabinoxylans after thermal treatment proteolysis, while their arabinose: xylose ratios were 0.39 and 0.36, with ferulic acid contents of 0.63 and 0.14 mg/g, respectively. Both products of arabinoxylans were molecularly identical by Fourier transform infra-red. Although the purity of the extracted arabinoxylans was improved with proteolysis, their intrinsic viscosity and viscosimetric molecular weight were affected. The extraction of arabinoxylans from brewers' spent grain by CaO nixtamalization alone or after additional proteolysis was successful to obtain purity and good antioxidant capacity.

Fish by-products are excellent sources of collagen. Acid-soluble collagen (ASC) derived from a mixed by-product of different fish species was hydrolyzed to obtain peptide fractions and evaluate their biological and functional activities. All fractions obtained (F1: ≥30, F2: 10-30, F3: 5-10, F4: 1-5, and F5: ≤1kDa) exhibited antioxidant activity at concentrations of 5, 10, and 15 mg/mL. However, F5 registered the highest reducing power (absorbance 0.366) and hydroxyl-radical-scavenging activity (91%) at 15 mg/mL; whereas the highest DPPH scavenging activity (81%) was also detected in F5 at 5 mg/mL. The solubility of F1, F2, and F3 was ≥ 95% at pH 7. The highest foaming capacity (78%), foaming stability (60%), and emulsion stability index (42 min) were registered for F1. However, the highest emulsifying activity index (130 m 2 /g) was for F3. These results place collagen obtained from a mixed by-product of different fish species as a potential biotechnological alternative for the industry., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Stenocereus thurberi is an endemic species in northwestern Mexico. It produces colorful fruits called pitayas that have an edible pulp. They have phytochemical compounds associated with biological activities. Ultrafiltration is a widely used method for the clarification of fruit juices and the recovery of phytochemicals. However, its effect has not been extensively studied in extracts. Therefore, the objective of this work is to study the effect of the ultrafiltration of pitaya extract ( Stenocereus thurberi ) on its phytochemical content, antioxidant capacity, and identification of phenolic compounds by UPLC-DAD-MS, providing greater knowledge about the pitaya. In this study, two extracts were analyzed, the unclarified extract (UE) and the clarified extract (CE). The antioxidant capacity was higher in the CE with 15.93 ± 0.42 mM TE/g, DPPH and 18.37 ± 0.016 mM TE/g, ABTS. The UPLC-MS analysis indicated the decrease in phenolic compounds in the CE and the presence of gallic acid and resorcinol, compounds that had not been identified in other species of Stenocereus spp. The correlation analysis indicated that all the phytochemicals present in the pitaya contribute significantly to the antioxidant capacity. The ultrafiltration process could be a viable option to improve the biological activity of the natural extracts.

Feruloylated arabinoxylans obtained from nixtamalized maize bran were evaluated in terms of physicochemical characteristics and antioxidant capacity when incorporated in frankfurter sausages. Concentrations of 0.15% and 0.30% of feruloylated arabinoxylans were incorporated in frankfurter sausages formulations and a control without feruloylated arabinoxylans was also prepared. Shear force, hardness, color measurement, proximate analysis, pH, titratable acidity, water-holding capacity, total phenols, and antioxidant capacity were evaluated. Phenolic content and antioxidant capacity were significantly higher ( P < 0.0001) in all treatments, sausages containing feruloylated arabinoxylans compared to the control. The results showed that there was a significant difference ( P < 0.0001) in total phenolic content and antioxidant capacity with all feruloylated arabinoxylans sausages treatments higher than control. Additionally, significant differences ( P < 0.0001) were obtained in the physicochemical parameters.

Freezing conditions affect fish muscle protein functionality due to its denaturation/aggregation. However, jumbo squid ( Dosidicus gigas ) muscle protein functionality remains stable even after freezing, probably due to the presence of low-molecular-mass compounds (LMMC) as cryoprotectants. Thus, water-soluble LMMC (<1 kDa) fraction obtained from jumbo squid muscle was evaluated by Fourier transform infrared spectrometry. From its spectra, total carbohydrates, free monosaccharides, free amino acids and ammonium chloride were determined. Cryoprotectant capacity and protein cryostability conferred by LMMC were investigated by differential scanning calorimetry. Fraction partial characterization showed that the main components are free amino acids (18.84 mg/g), carbohydrates (67.1 µg/mg) such as monosaccharides (51.1 µg/mg of glucose, fucose and arabinose in total) and ammonium chloride (220.4 µg/mg). Arginine, sarcosine and taurine were the main amino acids in the fraction. LMMC, at the mass fraction present in jumbo squid muscle, lowered the water freezing point to -1.2 °C, inhibiting recrystallization at 0.66 °C. Significant myofibrillar protein stabilization by LMMC was observed after a freeze-thaw cycle compared to control (muscle after extraction of LMMC), proving the effectiveness on jumbo squid protein muscle cryo- stability. Osmolytes in LMMC fraction inhibited protein denaturation/aggregation and ice recrystallization, maintaining the muscle structure stable under freezing conditions. LMMC conferred protein cryostability even at the very low mass fraction in the muscle.

The materials produced by the supercritical CO 2 drying have outstanding properties that allow the incorporation of molecules in their porous structure. In this context, dried chitosan nanoparticles including β-lactoglobulin were obtained. First, the nanoparticles in water suspension were produced by ionotropic gelation incorporating the protein with high loading efficiency. Later, solvent exchange and CO 2 supercritical drying procedures were performed. The physicochemical characteristics and structural properties were determined, demonstrating a stable porous structure in the dried materials and corroborating the presence of the protein after the drying. The CO 2 supercritical dried chitosan nanoparticles can be effectively resuspended in acidic aqueous medium remaining in the nanoscale with minimum effect on the loading parameters. The release of the β-lactoglobulin was highly influenced by the pH, reaching around 40% under acidic conditions in ten hours. The obtained results demonstrate the possibility to apply these chitosan materials as a controlled release material., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Pectins are plant cell wall natural heteropolysaccharides composed mainly of α-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.

A sulfated polysaccharide extracted from Navicula sp. presented a yield of 4.4 (% w/w dry biomass basis). Analysis of the polysaccharide using gas chromatography showed that this polysaccharide contained glucose (29%), galactose (21%), rhamnose (10%), xylose (5%) and mannose (4%). This polysaccharide presented an average molecular weight of 107 kDa. Scanning electron microscopy (SEM) micrographs showed that the lyophilized Navicula sp. polysaccharide is an amorphous solid with particles of irregular shapes and sharp angles. The polysaccharide at 1% (w/v) solution in water formed gels in the presence of 0.4% (w/v) FeCl₃, showing elastic and viscous moduli of 1 and 0.7 Pa, respectively. SEM analysis performed on the lyophilized gel showed a compact pore structure, with a pore size of approximately 150 nm. Very few studies on the gelation of sulfated polysaccharides using trivalent ions exist in the literature, and, to the best of our knowledge, this study is the first to describe the gelation of sulfated polysaccharides extracted from Navicula sp.

The objective of this study was to evaluate the efficacy of propolis extract (PE) to reduce lipid oxidation and microbial growth on beef patties during refrigerated storage. Beef patties were manufactured by incorporating PE in 4 different treatments: (1) Control (no PE addition); (2) commercial propolis 1 (2% w/w; CP1); (3) commercial propolis 2 (2% w/w; CP2); and (4) noncommercial propolis (2% w/w; NCP). Raw patties were wrapped with polyvinyl chloride and stored at 2 °C for 8 d. Total phenolic content (TPC), free-radical scavenging activity (FRS), and polyphenolic content of the PE were evaluated using high-performance liquid chromatography (HPLC). Lipid oxidation (thiobarbituric acid-reactive substances (TBARS), conjugated dienes (CnDs), metmyoglobin (MetMb%), pH variation, and color (L*, a*, b*, C*, and h*), and microbial growth (mesophilic and psychrotrophic bacteria) of patty samples were measured. NCP treatment demonstrated the highest FRS (64.8% at 100 μg/mL), which correlated with TPC and the presence of polyphenolic compounds. Lipid oxidation (78.54%, TBARS; 45.53%, CnD; 58.57%, MetMb) and microbial mesophilic and psychrotrophic growth (19.75 and 27.03%, respectively) values were reduced by NCP treatment in refrigerated samples after 8 d. These results indicate that PE has great potential as a natural antioxidant and antimicrobial additive to extend the shelf life of beef patties., (© 2014 Institute of Food Technologists®)

The grafting of fruits and vegetables influences fruit quality. The aim of the present work was to assess the effect of the rootstock and the scion on the antioxidant activity and the content in vitamin C, total phenols, lycopene and β-carotene of bell pepper. The cultivars Fascinato and Jeanette were used as scion and Terrano was used as rootstock. Four harvests in the production cycle of the vegetable were analyzed in a cultivation system under shading nets. The results indicate statistical differences in the content of these bioactive compounds between the varieties, between grafting and not grafting and between sampling dates (p ≤ 0.05). The vitamin C content, β-carotene, and antioxidant capacity proved significantly higher in Fascinato than in Janette. On average, grafting increased β-carotene and vitamin C concentrations and improved the antioxidant capacity, but had no influence on the total phenol or lycopene contents. It is concluded that grafting to the rootstock Terrano improves the nutritional quality of the fruit produced in both varieties of bell pepper studied.

A pectin (CAP) was extracted from the husk of Cicer arietinum L. Monosaccharide analysis of CAP revealed the dominance of galacturonic acid and smaller amounts of galactose, arabinose, rhamnose, glucose, xylose and mannose. Viscosimetric analysis showed that the intrinsic viscosity ([η]) and the molecular weight (MW) of CAP were 296 mL/g and 105 kDa, respectively. The degree of esterification (DE = 10%) was determined by FTIR spectroscopy. CAP exhibited a dose-dependent free radical scavenging activity, as shown by its DPPH radical inhibition. At 1.0 mg/mL CAP exhibited a scavenging rate of 29% on DPPH radicals. The evaluation of antioxidant activity suggested that CAP had good potential for DPPH radical scavenging activity and should be explored as a novel potential antioxidant.

A novel pectin was acid extracted from chickpea husk (CHP). CHP presented a 67% (w/w) of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G') modulus of 40 Pa and gel set time (G' > G″) of 3 min at 1% (w/v), and a G' of 131 Pa and gel set time of 1 min at 2% (w/v). The G' of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material.

This study examined the feasibility of using Trametes sp. grown under drought conditions to catalyze the covalent cross-linking of ferulated arabinoxylans. The rate of polymerization of ferulated arabinoxylans solutions at 0.5% (w/v) was dose dependent on the laccase concentration in the system. Above 1.2 nkat laccase/mg ferulated arabinoxylan, the rate of cross-linking reached a plateau, suggesting that the reaction reached saturation. For 2% (w/v) ferulated arabinoxylans treated with laccase (1.6 nkat/mg ferulated arabinoxylan), stable gels were formed after 4 h at 25 degrees C, with cross-linking contents (diferulic and triferulic acid) contents of 0.03 and 0.015 microg/mg ferulated arabinoxylan, respectively. This study demonstrated that Trametes sp. can be a source of biopolymer cross-linking enzymes like laccase.

The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v) in the presence of insulin or beta-lactoglobulin at 0.1% (w/v) was investigated. Insulin and beta-lacto-globulin did not modify either the gel elasticity (9 Pa) or the cross-links content (0.03 and 0.015 microg di- and triferulic acids/mg arabinoxylan, respectively). The protein release capability of the gel was also investigated. The rate of protein release from gels was dependent on the protein molecular weight. The apparent diffusion coefficient was 0.99 x 10(-7) and 0.79 x 10(-7) cm(2)/s for insulin (5 kDa) and beta-lactoglobulin (18 kDa), respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins.