查看更多>>摘要：Rice flour was substituted with RS4 microcapsules at 0%, 5%, 10%, 15% and 20% substitution levels to prepare functional extrudates. Pasting properties of rice flour -RS4 blends displayed significant (p <= 0.05) decreases in pasting properties with increasing RS4 content. The increase of RS4 content in flour resulted in the fall of both storage modulus (G') and loss modulus (G ''). The amylose content, RS content and water intake capacity of extrudates increased significantly with increasing RS4 content. Addition of RS4 microcapsules up to 20% did not affect the textural parameters of extrudates. Thermal transition temperatures of rice extrudates also increased with the percentage of increased RS4. SEM images of RS4-rice flour extrudate samples showed a more discontinuous structure with cracks and void spaces compared to control. FT-IR spectra revealed a new peak between 1244 and 1266 cm(-1) in RS4 enriched extrudates which is attributed P=O stretching in RS4. The survival of probiotics after extrusion demonstrated that RS4 microcapsules can be incorporated into the extrudates for preparation of functional foods. Addition of RS4 to rice extrudates up to 20% did not affect the overall acceptability of these products by consumers.
查看更多>>摘要：The impact of sodium alginate (SA) addition on the dough rheological properties and quality of highland barley-wheat composite noodles (HBWN) was systematically investigated. HBWN were prepared by 40% substitution of wheat flour with highland barley flour. And SA was added to HBWN in proportions of 0.1%, 0.2%, 0.3%, 0.4% and 0.5%. The results showed that SA enhanced the noodle quality regardless of the SA concentration, embodying in a lower cooking loss and water absorption, an increased hardness and springiness. Dynamic rheology analysis showed that SA addition elevated G' and G '' of dough. Pasting profiles of samples indicated that SA boosted the peak viscosity of starch granules. The relative crystallinity and ordered structures of the starch respectively obtained from X-ray diffraction and Fourier transform infrared spectroscopy decreased with the SA addition (0.1%-0.5%). Meanwhile, impact of SA on the molecular distribution of gluten network in HBWN was evaluated by SE-HPLC. SA induced protein depolymerizations in HBWN, resulting in the reduction of glutenin macropolymer (GMP). SEM and CLSM results exhibited that higher SA concentration (0.3%-0.5%) could promote the protein-starch interaction and contribute to a uniform and compact structure, which improved rheological properties of dough and texture properties of HBWN.
查看更多>>摘要：The effects of Mesona chinensis Benth polysaccharide (MCP) and sodium carbonate (Na2CO3) on the physical, optical, mechanical, thermal, and microstructure properties of sweet potato starch (SPS) film were studied. Rheological results showed that the addition of MCP and Na2CO3 increased the apparent viscosity, and visco-elasticity of the film-forming solution. The addition of MCP and Na2CO3 improved the tensile strength, elongation, and thermal stability of SPS film, and improved the solubility and swelling of SPS film. MCP and Na2CO3 enhanced the ability of SPS film to block ultraviolet radiation. Scanning electron microscope and atomic force microscope results showed that SPS and MCP were good compatible, and the surface of the formed film was smooth and flat. The results showed the addition of MCP and Na2CO3 improved physical properties of SPS film, and then meliorated mechanical and thermal properties, which widened the application of SPS film in the food packaging.
查看更多>>摘要：In the present study, the probiotic potential of lactic acid bacteria (LAB) isolated from different dairy sources were evaluated, and probiotics with anti-allergic activity were further screened based on the hyaluronidase inhibition assay and the degranulation of RBL-2H3 cells in vitro. As a result, Out of 20 strains, 15 LAB exhibited desirable probiotic properties and safety in vitro. Considering the suppressive activities on hyaluronidase and beta-hexosaminidase release in degranulation-induced RBL-2H3 cells, strains LZ077E, LZ183E, and LZ260E exhibited potential probiotic properties that could be useful for alleviating allergic diseases. To evaluate the reliability of this result, the efficacy of these three strains on the expression of some cytokines and proteins in the signal pathway related to the Fc epsilon RI receptor on the RBL-2H3 cell surface were analyzed. The results show three strains exhibited remarkable downregulation of histamine and cytokines TNF-alpha and IL-4. Similarly, immunoblot analysis revealed that the probiotics also significantly decreased the phosphorylation of Lyn and Syk in RBL-2H3 cells. Our preliminary results may provide some scientific support for the use of probiotics for the treatment of allergic and inflammatory diseases, as well as the rapid screening of anti-allergic active probiotics in vitro.
查看更多>>摘要：Bacteriocins are known to inhibit various foodborne bacteria and their biofilms; however, few bacteriocins with activity against food-derived Staphylococcus aureus have been reported. Here, a novel bacteriocin (XJS01) from the Lactobacillus salivarius strain CGMCC2070 was obtained, purified, and extensively characterized. Molecular mass and amino acid composition of XJS01 were 666.31 Da and F-S-G-L-A-G-D, respectively. XJS01 inhibited the S. aureus strain 2612:1606BL1486 (S. aureus_26), which was originally isolated from chicken meat. Also, XJS01 showed good resistance to heat treatment, and was only susceptible to pepsin treatment. The minimum inhibitory concentration of XJS01 against S. aureus_26 was 9.85 mu g/mL, which is lower than previously reported levels for most described bacteriocins. Furthermore, exposure to XJS01 also decreased viability and significantly inhibited (p < 0.05) planktonic S. aureus_26 cells. Biofilm formation of S. aureus_26 was also significantly inhibited (p < 0.05). The results of electron microscopy showed that XJS01 impaired membrane permeability in S. aureus_26, caused leakage of cytoplasmic content, and led to cell deformation. In summary, this study identifies the bacteriocin XJS01 as a potentially candidate for the control of S. aureus in foods in either planktonic or biofilm states.
查看更多>>摘要：Bee pollen is the result of flower pollen collecting and processing by honey bees. Due to its nutritional profile, it is considered a functional food. The present work aimed at evaluating labelling, pH, Aw, microbiological and mycotoxicological profile of 29 bee pollen samples (dried and fresh) purchased at retail in Tuscany (Italy). Only one pollen lacked more than two mandatory indications. Aw ranged from 0.19 to 0.77, while pH from 4.50 to 6.10. Fresh samples presented higher bacterial loads than dried samples. Total bacterial counts, Enterobacteriaceae, yeasts and molds and lactic acid bacteria ranges were 2.2-6.0, <2-4.1, <1-4 and <2-6.0 log CFU/g, respectively. Escherichia coli, Staphylococcus aureus, Bacillus cereus and sulphite-reducing clostridia loads were lower than the detection limit; Salmonella spp. and Listeria monocytogenes were always absent. As for mycotoxins, total aflatoxins were detected in all samples (5.2-34.4 mu g/kg). Higher deoxynivalenol concentrations were detected (maximum: 179.7 mu g/kg). Since the occurrence of spoilage microorganisms seems to be frequent, leading to possible alterations of the organoleptic profile, the microbiological quality of fresh bee pollen should be monitored. The risk related to the presence of pathogenic microorganisms seems to be very low, while attention must be paid to the presence of toxic metabolites.
查看更多>>摘要：Ochratoxin A (OTA) is a mycotoxin frequently found in wines, with an allowed maximum limit of 2.0 mu g/L. To optimise OTA removal from white and red wines at high levels (10.0 mu g/L) using activated carbons (ACs) different commercial deodorising ACs were tested. OTA elimination from white wines was less dependent on ACs characteristics, with 100% removal with all but one AC with the lowest total pore volume. For red wines, only one of the ACs with higher abundance of mesopores was successful in completely removing OTA. This decrease in performance was due to the competition of anthocyanins for ACs mesopores. ACs treatment impacted positively on white wine chromatic characteristics, decreasing the yellowness-brownish colour but for the red wine it was observed a higher but limited impact (maximum 24% decrease) on wine colour. ACs pore volume distribution, with pore sizes in the range 42.6-55.9 angstrom and 125.6-137.4 angstrom were important for efficient OTA removal. These results will allow the rational design of ACs with pore volume characteristics for OTA elimination with less impact on wine colour. Therefore, it was shown for the first time that AC with appropriate pore size distribution can remove completely OTA from white and also red wines.
Garcia-Vieyra, M. IsabelSantiago-Garcia, Patricia A.Mellado-Mojica, ErikaLeon-Martinez, Frank M....
11页
查看更多>>摘要：In this work, agavins (agave plant fructans) potential as fat replacer in dairy products was evaluated. Yogurt nonfat and fat reduced samples were prepared, agavins from Agave angustifolia and A. potatorum species were added to fat reduced products to evaluate their effect on the physicochemical, rheological, and sensory properties in the final products. Significant differences in the viscosity, syneresis and water retention capacity were observed among samples. All yogurts exhibited characteristics typical of a weak viscoelastic gel (G'>G") and strainthinning behavior. Physicochemical and rheological differences were strongly related to the agavins amount in yogurt fat-reduced samples. Agavins did not impact sensory attributes such color, smell, and taste in fact; they improved mouth feel and texture. HPAEC-PAD profiles demonstrated that agavins remain unaffected along the yogurt elaboration process. FTIR spectra showed remarkable differences on all final products composition, been more evident on fatty acids and carbohydrates regions. FTIR-PCA models allowed samples classification among treatments and samples discrimination according to the agavins content. Agavins addition to dairy products has a great potential as functional ingredient in the manufacture of low-fat, prebiotics and symbiotic products. Finally, compiled information increases our knowledge on the broad technological functionality that agavins may have in other food industry niches.
查看更多>>摘要：Fusarium solani (CICC 2603) is one of the main postharvest spoilage strains of many fruits and vegetables. This research was to investigate the synergistic antifungal mechanism of thymol and salicylic acid (S-TSA) on F. solani. Morphological observation showed that the cell structure and morphology changed seriously after S-TSA treatment. Determination of F. solani stained cells with propidium iodide (PI) indicated that S-TSA damaged the integrity of cell membrane, and the contribution of salicylic acid was greater than that of thymol. Meanwhile, the increase in the absorbance of 260 nm and 280 nm demonstrated that S-TSA caused the leakage of cell contents severely, and the contribution of thymol was greater than that of salicylic acid. In addition, the decrease of ergosterol biosynthesis showed that S-TSA interfered with membrane function of F. solani. Mitochondrial membrane potential (MMP) and enzymes activities of tricarboxylic acid (TCA) cycle experiments demonstrated that the mitochondrial function was seriously injured in F. solani. These results showed that S-TSA inhibited the activity of F. solani more effectively than thymol or salicylic acid alone, by disrupting integrity and function of the cell membrane, causing leakage of the cell contents, meanwhile inhibiting function of the mitochondria, ultimately resulting in cell death.
do Nascimento, Edilza SilvaCaju de Oliveira, Julia MarianoJocelino Gomes de Lacerda, Jose ThallesMontenegro, Samara Batista...
8页
查看更多>>摘要：This study aimed to produce a yam protein concentrate (YPC), Dioscorea cayennensis, to evaluate its protein digestibility and the peptide profile generated through simulated gastrointestinal digestion (GID). After concentration, the YPC that resulted in 64.0% protein was obtained. Simulated GID and free amino acids analysis were performed to evaluate its digestibility. For the peptide profile was evaluated by means of structure, molecular weight (MW) (nano-LC-ESI-MS/MS and SEC-FPLC), and hydrophobicity (RP-HPLC). Roughly 71.0% of peptides showed MW < 2 kDa after GID. The peptide sequences KQAVNENAINNARPLQPTN, GRSDPFLSDL, and KNEINAGVVDPNQLQF were identified in the gastric digestion. These sequences were further digested in the intestinal phase, yielding the NAINNARPL, GRSDPF, and VVDPN peptides. The GID process generated molecules with smaller MW, with consequent exposure of ionizable and functional groups, potentializing the yam proteins bioactive capacity. The peptides obtained after the digestion should be explored in future studies with the objective of understanding the bioactive potential of these molecules for human health.
NSTL
Elsevier