查看更多>>摘要：Whey protein isolate-dextran (WPI-dextran) conjugates were acquired via Maillard reaction for different durations (1-7 days) and their potential to govern the size and stability of colloidal nanoparticles formed from heating electrostatic complexes of WPI-dextran conjugates and chondroitin sulfates was assessed. The grafting degree and browning index gradually increased with the reaction time. The intensity of amide bands increased in the first 2 days and then declined. As the duration increased, the content of alpha-helix increased from 23.9% to 29.6%, while I3-sheet and random coil decreased from 23.8% and 38.1% to 19.6% and 32.7%, respectively. Moreover, the surface hydrophobicity was reduced as the conjugation progressed, while surface and total sulfhydryl content gradually increased from 5.3 and 15.4 mu mol/g to 11.0 and 17.9 mu mol/g, respectively. Meanwhile, fluorescence intensity of conjugates decreased with prolonged durations. These changes with increasing grafting degree prompted greater steric hindrance, weakened hydrophobic interaction, and improved stability of protein during heating, thus facilitating the decreasing diameter of the corresponding heat-induced nanoparticles. In comparison with the nanoparticles derived from non-conjugated mixture of WPI and dextran, those from WPIdextran conjugates showed an excellent stability to aggregation and dissociation upon synergistic influence of pH variation (1-10) and enhancing ionic strength (0-4 mol/L).
查看更多>>摘要：The present study explores the role of honey diastase as a texture-modifier in starchy food system using high diastase honey bee honey (HBH) and low diastase kelulut bee honey (KBH). Three types of dodol, namely condol (conventional dodol), keludol (dodol incorporated with KBH), and honeydol (dodol incorporated with HBH) were prepared and assessed for textural, structural breakdown, and mechanical parameters after a 7-day ageing period. Honeydol had a weakened network structure as reflected by the significantly lower (p < 0.05) hardness, adhesiveness, springiness, cohesiveness, gumminess, work 1st, winf, w1, and Fmax than those of keludol and condol. Structural breakdown of honeydol required the least work, as substantiated by a higher risk of structural collapse with the significantly largest (p < 0.05) pore diameter. However, honeydol retained its chewability through its fast structure recovery rate as evidenced by the significant higher (p < 0.05) n1 and k1 values. In addition, anti-staling effect of diastase was apparent in honeydol as exhibited by the significantly lower (p < 0.05) Delta H and low absorbance intensity in 800-1200 cm-1 (saccharide) and 3000-3600 cm-1 (water) regions, that depict a less extent of starch retrogradation. In conclusion, the use of HBH with diastase could impart changes in texture of high starch product such as dodol.
查看更多>>摘要：In order to explore the interaction between gliadin/glutenin (gli/glu) and starch granules, rheological, microscopic and molecular structural properties of gluten-starch dough with varied gli/glu ratios during mixing was investigated. The effect of gli/glu ratio on dough elasticity (G ') and strength (extension resistance) depended on the mixing state. The increase in gliadin ratio could weaken the dough strength at optimum-mixing stage while enhance it at under and over-mixing stages. At optimum stage, increasing gliadin could embed in and reduce the intermolecular attraction of glutenins, leading to lower stability (higher z values) of dough. At under and overmixing stages, increasing gliadin could promote the formation of a temporary gli/glu-starch physical network structure, leading to higher stability (lower z values). Polymerization or depolymerization of glutenin macropolymer (GMP) depended on both the gli/glu ratio and mixing time, which could be correlated to the changes in rheological behaviors. The cohesiveness of glutenin caused large clumps in dough with high glutenin content, while the increase in gliadin ratio was favor for the dispersion of glutenin, promoting the formation of gluten network. Covalent and hydrogen bonds were the main interactions for high glutenin content dough, while hydrophobic and hydrogen interaction became predominate with increasing gliadin ratio.
查看更多>>摘要：This study investigated the changes in free amino acids (FAAs), 5 '-nucleotides, and lipid compositions of Manila clams (Ruditapes philippinarum) collected from December 2017 to November 2018. High-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry was used to quantify twenty-one FAAs and six 5'-nucleotides. Lipid profiles were explored by ultra-performance liquid chromatography coupled with a Q-Exactive Orbitrap mass spectrometer with an untargeted lipidomic approach. Results showed significant monthly changes of FAAs, 5 '-nucleotides, and lipids profiles. Alanine, glutamic acid, glycine, and aspartic acid, which contributed to the sweet and umami flavor, were the most abundant FAAs in Manila clams. Totally 90 glycerides, 76 glycerophospholipids, 21 lyso-glycerophospholipids, and 52 fatty acids were identified in Manila clams. Among these lipids, most of them possessed a high-level of unsaturation degree. The unsaturation degree of lipids in February, March, and April was the highest, showing the best nutritional value of Manila clams.
Sarmast, ElhamFallah, Aziz A.Jafari, TinaKhaneghah, Amin Mousavi...
10页
查看更多>>摘要：In this study, alterations in aflatoxin M1 (AFM1) levels during the manufacturing of cheese were assessed through a systematic review and meta-analysis. The overall result based on weighted response ratio (R*) demonstrated an increase of 77.2% (R* = 1.772, P < 0.001) in AFM1 level of cheese compared to milk after cheese manufacturing, while a reduction of 49% (R* = 0.510, P < 0.001) in the toxin level was found in whey. The rank order of increased AFM1 level in three types of cheese was hard (168%) > semi-hard (68.7%) > soft (60.6%). A higher increase in AFM1 level was found in cheese produced from the milk without starter culture (156.5%, R* = 2.565, P < 0.001) compared to that produced from the milk contained starter culture (37%, R* = 1.370, P < 0.001). The increased AFM1 level in cheese produced from naturally contaminated milk was 2.1 folds higher than that produced from artificially contaminated milk. The overall result based on the rate of AFM1 change (%) demonstrated a significant reduction of AFM1 level after ripening/storage period (-11%, P = 0.007); moreover, this reduction was noticeable (-21.1%, P = 0.009) in cheese made from the milk contained starter culture.
Celik, Omer F.Con, Ahmet H.Saygin, HayrettinSahin, Nevzat...
8页
查看更多>>摘要：Potential lactobacilli isolates (20) from traditional yogurt samples were primarily selected based on their antimicrobial activity against common pathogens of Escherichia coli and Staphylococcus aureus. Following this, the highest acidity values were determined in K1 (0.63%) and EPSC2 (0.61%) isolates after 6 h; KKC1 (1.62%) and EPSC2 (1.59%) after 24 h. The highest proteolytic activity in the first 36 h of incubation was observed in K11B, M2, CBB5 and CBB3 isolates while the lowest activity was in K10, M6, and KKC2 isolates, respectively. Subsequently, 10 isolates that carry the potential to be used as yogurt starter cultures were picked and identified at the molecular level using 16S rDNA sequences and a phylogenetic tree was created. The closest species to all of the selected isolates was determined to be Lactobacillus bulgaricus. The flavor profiles of these isolates indicated that the highest acetaldehyde concentrations were detected in the KKC1, M6, and KKC2 isolates while these values were found to be higher than that of the commercial Lactobacillus. Consequently, CBX, CBH4, M6, EPSC2, and KKC2 were found to possess the potential to be used as starter cultures therefore they could be recommended for utilization in fermented dairy products, especially yogurt.
查看更多>>摘要：In our current study, high-intensity ultrasound was employed to enhance the bioactive, functional, structural, and digestibility properties of potato protein. Potato proteins were extracted from potato fruit juice (PFJ), both potato protein powder and patatin were exposed to ultrasound at 600 W for 10, 15, and 20 min. We observed noticeable alterations in the functional and bioactive properties of both potato powder and patatin. Ultrasound treatment for 20 min was the optimal for the enhancement of both functional and bioactive properties. There was a significant increase of 30%, 33% for DPPH, and 16%, 23% OH radical scavenging activity for potato protein powder and patatin. Also, an increase of 12% in the digestibility of high intensity ultrasound (HIU) treated potato protein was observed. Furthermore, fourier-transform infrared spectroscopy FTIR showed a substantial decrease in the amide I and amide II band for treated samples. Scanning electron microscope (SEM) showed the smallest fragments for both potato protein (PP) and patatin in HIU treatment for 20 min. The tested functional properties, including emulsifying ability index (EAI), emulsifying stability (ESI), foaming ability, solubility, and zeta potential, were significantly enhanced. There was a significant decrease in particle size, foaming stability in both potato protein powder and patatin.
Nero, Luis AugustoAndretta, MilimaniAlmeida, Thaiza T.Ferreira, Leticia R....
8页
查看更多>>摘要：The lactic microbiota of the Minas artisanal cheese (MAC) produced in the Serro region was characterized by culture-dependent and -independent methods. Samples of Serro MAC (n = 55) were obtained and plated for lactic acid bacteria (LAB) enumeration. Isolates (n = 176) were subsequently identified by 16S rRNA sequencing as lactobacilli, Lactococcus lactis and Enterococcus sp. LAB counts and the distribution of identified species did not differ by producer city, producer farm size, starter culture and time of production (P > 0.05). DNA from samples was subjected to high-throughput 16S rRNA sequencing and L. lactis was the predominant species in all samples. Alpha-diversity indices (species number, diversity, richness) and beta-diversity analysis did not differ between samples (P > 0.05). Core microbiota for all cheese samples included L. lactis, Streptococcus salivarius, S. thermophilus and Acinetobacter johnsonii. Here, we were able to show that lactobacilli and L. lactis are the dominant lactic groups and species in the Serro MAC, supporting the establishment of a typical microbial signature for this cheese.
查看更多>>摘要：This study evaluated the relationship between the formation of heterocyclic amines (HAs) during the dry heat treatment of soy protein isolate (SPI) and the changes in the physical and chemical properties of the SPI. After heat treatment of SPI at 150 degrees C for 10 min (130 degrees C for 60 min), high molecular weight proteins ( 35 KDa) were thermally decomposed into carbonylation low molecular weight (LMW) proteins (<20 KDa) and peptides, while the HAs content began to increase substantially (p < 0.05). In the dry heated SPI, the production of HAs was highly correlated with protein solubility (rs = -0.73--0.99, p < 0.05), oxidation degree (rs = 0.67-0.98, p < 0.05), and ninhydrin-reactive amino nitrogen content (rs = --0.70--0.88, p < 0.05). Finally, three plant-based meat alternatives which use SPI as the main protein material were cooked at three different temperatures (170, 190 and 210 degrees C), and the contents of HAs in the plant-based meat alternative products were far lower than that in meat products.
查看更多>>摘要：This study aims to identify the antimicrobial mode of action of sodium acid sulfate (SAS) and potassium acid sulfate (KAS) against three major foodborne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT 104, and Listeria monocytogenes. The overnight grown cultures of the target pathogens were subjected to SAS and KAS treatments to identify the minimum inhibition concentrations of each antimicrobial. The impact of SAS and KAS treatments on the target pathogens at bio-molecular levels was also studied. To help determine if the mode of action is pH-driven, SAS and KAS's antimicrobial efficacies were also compared against hydrochloric acid (HCL). The MIC values of SAS and KAS for all three pathogens were 7.5 mg/mL while for HCL, the MICs were greater than 30 mg/mL. Similarly, SAS and KAS treatments resulted in more damage to all target pathogens and increased leakage of nucleic acid, protein, and ions than HCL treatments. Transmission electron microscope images also revealed that 7.5 mg/mL SAS and KAS treatments resulted in significantly more visible cell damage in S. Typhimurium and E. coli O157:H7 than HCL treatments. The study's findings indicate that the SAS and KAS could be the function of pH, oxidation of cell components, and osmolarity.
NSTL
Elsevier