查看更多>>摘要：The conjugation with carbohydrates potentially improves the functional properties of proteins. This study aimed to investigate the physical and oxidative stability of oil-in-water emulsions stabilized by bitter almond gum-soy protein isolate (BAG-SPI) conjugates (1:1, 1:3, 3:1). The dry-heated Maillard conjugation significantly improved water holding capacity and solubility of SPI proportion with BAG ratio in the conjugate (p < 0.05). The conjugation with BAG changed the particle size and zeta potential of SPI remarkably. This process changed the rheological behavior of SPI from Newtonian toward shear-thinning, except for BAG-SPI (1:3) conjugate, which behaved like SPI. The emulsion prepared with BAG-SPI (3:1) conjugate exhibited the highest physical stability due to its potential to produce smaller oil droplets and higher viscosity. However, the conjugation process declined oxidative stability. Therefore, a combination of SPI and glycated SPI with a higher BAG ratio may be suitable for stabilizing the emulsions for a long time.
查看更多>>摘要：This is the first scientific study of the unique Bulgarian Cherni Vit green cheese based on 16S and ITS2 NGS metagenomics, accomplished on the Illumina HiSeq 2 x 250 bp paired end reads in order to obtain an overview of the microbial composition. The results revealed a rich microbiota, composed of on average of 120 eubacterial and 16 fungal species. Firmicutes were represented by the families Strepotococcaceae, Lactobacillaceae and Staphylococcaceae, while the Actinobacteria were represented mainly by the genera Brevibacterium and Corynebacterium. Low counts of Proteobacteria were also detected, mainly halophiles of the genera Cobetia and Psychrobacter. Almost all (99.99%) of the detected fungi belonged to Ascomycota, represented almost equally by the families Eurotiomycetes (exclusively by Penicillium roqueforti), Saccharomycetes (mainly by the genera Debaryomyces, Pichia, Candida and Kluyveromyces) and Sordariomycetes (mostly by Scopulariopsis flava). The performed diversity analyses revealed that despite some differences, which can be attributed to environmental factors, and the time of the ripening, all of the four batches displayed very rich but similar microbiota. We found a potentially beneficial microbiota with the potential to inhibit the growth of pathogenic bacterial species, as well as to neutralize possibly produced mycotoxins, as described in numerous research on raw milk dairy products.
查看更多>>摘要：To explore the feasibility to enhance drying kinetics and keep the active ingredients of the aqueous extracts of Callicarpa nudiflora Hook. et Arn., the effects of vacuum drying under different vacuum pressure (8, 20, 50 kPa), drying temperature (80, 95, 110 degrees C), and the thickness (4, 8, 12 mm) on the drying kinetics, energy consumption and the contents of verbascoside and galuteolin of the aqueous extracts were evaluated. Boiling heat transfer and low-pressure mass transfer of the aqueous extracts during drying were analyzed. Among different drying conditions, the vacuum pressure of 20 kPa, drying temperature of 110 degrees C and the thickness of 4 mm were recommended as the most suitable ones for vacuum drying of the aqueous extracts of Callicarpa nudiflora Hook. et Arn. in terms of the moisture ratio and the quality of final product.
查看更多>>摘要：As an emerging packaging material, hydrogels have been attracting attention to inhibit foodborne pathogens by encapsulating antimicrobial substances. Herein, an antibacterial packaging material was prepared via incorporation of methyl-beta-cyclodextrin/Satureja montana L. essential oil inclusion complexes (MCD/SEO-ICs) into soy soluble polysaccharide (MCD/SEO-SSPS) hydrogel. During, the addition of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) facilitated the formation of amido linkage between -NH2 and -COOH. Compared with SSPS hydrogel, the MCD/SEO-SSPS hydrogel exhibited a more compact structure. What's more, physical characterization indicated that combining MCD/SEO-ICs with SSPS could improve the hardness, adhesiveness and springiness of hydrogel. More importantly, a good antibacterial activity of SPSS hydrogel was obtained with the addition of MCD/SEO-ICs. On this basis, the application test demonstrated that the prepared MCD/SEO-SSPS hydrogel could reduce the visible count of Staphylococcus aureus (S. aureus) in meat samples by 3.5 Log CFU/g during 7-days storage, which retained the freshness of chilled pork and extended the shelf life. The above results indicated that MCD/SEO-SSPS hydrogel can be used as a safe and effective active packaging material for chilled meat preservation.
Bruno, E.Lupi, F. R.Martin-Pinero, M. J.Girimonte, R....
9页
查看更多>>摘要：The propensity of edible fiber to structure aqueous suspensions can be tuned also by modifying the process adopted to disperse it in water. In this paper a rotor-stator homogenizer and a high pressure microfluidizer are used to produce fiber aqueous suspensions with increasing fiber content, investigating the effects of process conditions on rheological properties and particles-size distribution of these materials. An isoenergy criterion was chosen to vary the power supplied by the rotor-stator device to suspensions, and, on the other hand, two operating pressures were used to produce a second set of suspensions via microfluidization. The obtained results highlighted the greater propensity of microfluidizer to disrupt particles, stabilizing the final system by varying mainly the network extension. Finally, a fractal model was adopted to predict the rheological behavior of suspensions as a function of fiber content.
查看更多>>摘要：Longan peel, which is fruit by-product, is known for its antioxidant activities regarding the presence of phenolics. To minimize the use of synthetic antioxidants in food, natural antioxidants including phenolics from plant extracts have received much interest. This study screened combinatorial pretreatments between longan peel extract (LP) and food additives including vitamin E (E) and ascorbyl palmitate (AP) for application in refined tuna oil. Our results demonstrated synergistic effects of LP/E/AP pretreatment against lipid oxidation in the oil. Under Rancimat accelerated oxidation at 100 degrees C, the LP/E/AP combination exhibited a synergy by significantly increasing induction period in comparison to the blank control. Similarly, under accelerated storage at 50 degrees C, this combination significantly decreased peroxide value, conjugated dienes and thiobarbituric acid reactive substances. Gas chromatography analysis demonstrated that the LP/E/AP combination maintained the levels of polyunsaturated fatty acids, which was comparable with that of a synthetic antioxidant i.e. butylated hydroxytoluene (BHT). In addition, the combined pretreatment resulted in synergistic decrease of free radicals in the oil, which might contribute to the antioxidative effects. Collectively, our results have demonstrated the potential of LP used in combination with particular food additives to enhance protective effects against lipid oxidation.
查看更多>>摘要：The process of raw starch conversion has attracted extensive attention in recent years due to its high energy conversion efficiency and saving of operational costs. In this study, extensive hydrolysis of raw starch by alpha-amylase AmyM from Corallococcus sp. EGB was investigated with robust substrate and products tolerance. AmyM showed broad substrate specificity toward raw starches with different types, and kept active and stable over a wide range of temperatures (30-70 degrees C) and pH values (5.0-9.0) and recycling. The Vmax values of AmyM towards wheat and corn raw starch were 1111 and 741 mu mol/min/mg without depending on Ca2+, respectively. SEM analysis showed that AmyM hydrolysis results in the formation of porous and creviced surfaces around the starch granules peripheries. The cost-effective conversion of raw starch for the production of maltooligosaccharides (MOSs) was identified. AmyM achieved high hydrolysis degree of 90% for 30% wheat and corn raw starch after 20 h at 45 degrees C with 5 U per mg of raw starch, resulting in formation of 70% MOSs and 30% dextrin. During this process, maltose (G2), maltotriose (G3) and maltotetraose (G4) were produced synchronously with G9 and G11, indicating the potential application in enzymatic conversion of raw starch under low temperature.
Tokay, Fahrettin GokhunAlp, Ali CanYerlikaya, Pinar
8页
查看更多>>摘要：In this study, the effects of MTGase addition (0, 0.16, 0.32%), pressure weight (0, 2.54, 5.09 gf/cm(2)) and setting time (4, 14, 24 h) at 4 degrees C on restructured European seabass (Dicentrarchus labrax) meat were systematically optimized with RSM in order to obtain a ready to eat seafood product. The optimized process was characterized by drip loss, total free amino acids and hardness value. The RSM study demonstrated that, 0.32% MTGase, 17.5 h of setting time and 3.56 gf/cm(2) of pressure weight were the optimal processing parameters.
查看更多>>摘要：Bacteriophages are considered a promising candidate for controlling food pathogens. In this study, we isolated and characterized S. aureus-infecting bacteriophages, and investigated their potential for antibiotic substitute and bacteriophage cocktail effect in Luria-Bertani (LB) broth and skim milk. Bacteriophages LSA2308 and LSA2366 possessing lytic activity against drug-resistant S. aureus were isolated. The latent period of LSA2308 and LSA2366 was approximately 20 and 10 min, with burst size of 407 and 258 PFU per infected cell, respectively. A combination of LSA2308 (or LSA2366) and 1/2 MIC ampicillin achieved better clearance of S. aureus CR003 in LB broth than treatment with either bacteriophage or ampicillin alone. Biocontrol with 10(5)-10(7) PFU/mL LSA2308 or LSA2308/LSA2366 cocktail was effective in LB broth, whereas it was less active in skim milk. Compared with treatment using 10(5) or 10(6) PFU/mL bacteriophages, the bactericidal efficacy of 107 PFU/mL bacteriophages on single or mixed S. aureus strains in skim milk was the best at 4 and 25 degrees C, revealing a dose-dependent mode. Our study further expands the repertoire of bacteriophages infecting drug-resistant S. aureus, and provides insights into the control of S. aureus in milk production chain.
Glomm, Wilhelm R.Wubshet, Sileshi G.Lindberg, DianaDankel, Katinka R....
11页
查看更多>>摘要：Immobilization of enzymes onto magnetic particles can potentially allow for enzyme reuse, which can significantly reduce the cost associated with e.g. enzymatic protein hydrolysis (EPH) of fish and meat by-products. Here, we report glutaraldehyde-mediated immobilization of a food-grade protease (Subtilisin A) onto magnetic silica particles using three different amine ligands; a short, brush-like linker (aminopropyl trimethoxysilane), a long, flexible linker (Jeffamine), and a gel-like coating (chitosan). The three coupling strategies were evaluated and compared with respect to the amount of immobilized protease, enzyme activity and catalytic performance in the hydrolysis of chicken meat and turkey tendons, respectively. The particle systems showed high reusability (<85% activity remaining after six consecutive cycles) and storage stability (<93% activity remaining after 25 months storage). Particle-immobilized enzyme systems were able to catalyze degradation and extraction of protein from chicken meat and turkey tendons.
NSTL
Elsevier