Panigrahi, ChirasmitaMishra, Hari NiwasDe, Sirshendu
11页
查看更多>>摘要：The efficacy of ozone treatment against Leuconostoc mesenteroides (LM), Saccharomyces cerevisiae (SC) and total coliforms (TC) was investigated. The effects of three ozone doses per unit volume (ODV), 0.12, 0.28 and 0.45 mg/min ml on microbial disinfection were studied. At the end of treatment (50 min), maximum reductions of LM (2.8 log), SC (2.18 log) and TC (3.4 log) were achieved with ODV of 0.45 mg/min ml. Various non-linear models, viz., Weibull+tail, Coroller, Geeraerd, Cerf, modified Gompertz and log-logistic were attempted to elucidate inactivation kinetics of microorganisms. The microbial tailing behaviour was well described by model parameters, like, tailing ratio, residual population and minimum cell concentration. The sensitive and resistant fractions of microbial population were characterized by the estimated scale parameter and destruction rate constants. Statistical measurements (adjR(2): 0.97-0.999) and validation indices (accuracy factor: 1.02-1.27, bias factor: 0.965-1.25) indicated satisfactory performance of all models. The Akaike's theory was employed for model selection. Coroller model was identified as the most accurate model for LM and TC showing the lowest Akaike increment in 71.82% and 54.67% of the inactivation curves, respectively. Log-logistic model was selected as the best-fit model for SC owing to its reliability in describing 81.37% of their survival curves.
查看更多>>摘要：In the present work, we have studied the effect that some extraction techniques, such as ultrasound or microwaves, produce on the aroma of red wines, when applied to processes of extractive nature, such as pre-fermentative maceration or ageing with oak chips (Spanish oak - Quercus pyrenaica and French oak - Quercus robur). The volatile profile has been studied by means of gas chromatography coupled with olfactometric and mass spectrometric detection. Sensory analysis of all the wines produced has also been conducted. Although no indications were found to show that the pre-fermentative treatment with microwaves or ultrasound modified the sensory profile of the wines, the application of such energies during the ageing phase showed some positive trends at sensory level, also confirmed by the olfactometric measurements. The application of ultrasound during the ageing of the wines resulted in a greater contribution of red fruits, aromatic intensity and wood than that obtained through microwaves. Regarding the type of oak chips, Spanish oak provided more volatile compounds than French oak and with a lower proportion of undesirable aromas. At the sensory level, Spanish oak also showed greater aromatic intensity and higher values for the wood descriptor, being preferred by the panel of judges.
查看更多>>摘要：Low-temperature tenderization is an important aspect in the processing of sea cucumber. Oxidative reactions induce protein aggregation or degradation during thermal treatment. However, whether protein oxidation occurs in sea cucumber during tenderization is unclear. Moreover, the effects of heat treatment on the protein structure in sea cucumber have not been well explored. In this study, Apostichopus japonicus body wall (AJBW) were tenderized at 37 degrees C and changes in the protein microstructure of AJBW and the relative indicators of oxidative reactions, including carbonyl, sulfhydryl, and amino constituents, were investigated. The findings indicated that the collagen fibers were depolymerized and the maximum denaturation temperature of collagen was significantly reduced after tenderization, suggesting that this process induced structural changes in collagen fibers. Furthermore, amino acid side-chain modifications and the formation of an unstable secondary and tertiary conformation indicated oxidation of the water-soluble proteins. The findings revealed that tenderization of AJBW caused the destruction of the collagen fiber structure and resulted in protein oxidation and degradation. Therefore, our study lays the foundation for subsequent research for determining the mechanism of tenderization.
查看更多>>摘要：This paper aims to study the mechanical properties of fish oil microcapsules made of different food-grade formulations and processing conditions, which is crucial to maintaining their mechanical integrity in further compaction for developing the final dosage form of tablet. The combination of gelatin and gum Arabic or maltodextrin were use as wall materials. Spray drying, complex coacervation, and double encapsulation (coacervation followed by spray coating) were used to prepare different fish oil microcapsules. Both fundamental physical properties and mechanical properties of microcapsules were investigated. The mechanical characterization results were obtained using a micromanipulation technique and revealed that the mean rupture forces of individual microcapsules ranged from 0.44 +/- 0.11 to 1.73 +/- 0.27 mN and tended to increase with increasing particle size. The Young's modulus of microcapsules was determined by fitting the experimental force versus displacement data with the Hertz model. The microcapsules prepared by coacervation of gelatin and gum Arabic followed by spray coating with a mixture of gelation and maltodextrin were the strongest and stiffest based on the calculated nominal rupture stress and Young's modulus respectively. These findings can provide guidance on choosing the most desirable formulation and processing conditions to produce strong microcapsules with desirable barrier properties for industrial applications.
查看更多>>摘要：This work analyzed the antifungal capacity of different sanitizers allowed in the food industry against species involved in the spoilage of dairy and meat products and compared the results with sanitizing products used in the food industry. Tests were carried out according to the protocol for testing the antifungal effects of chemical sanitizers of the European Committee for Standardization (CEN) and the French Standard NF-T-72281. Industry data were obtained by electronic form. Aspergillus (A. westerdijkiae, A. pseudoglaucus) and Penicillium (P. commune, P. roqueforti, P. polonicum) were tested against benzalkonium chloride, biguanide, peracetic acid, sodium hypochlorite, and an ortho-phenylphenol-based fumigant. The spoilage fungi isolated from meat products were resistant to most of the sanitizers and concentrations tested. The lowest concentration specified in the product label is the closest to the usually applied in the food industry and was never effective against the spoilage species tested. Peracetic acid was the most common agent employed by the food facilities surveyed and the most effective sanitizer at the highest concentration evaluated, especially against cheese spoilage species. Nevertheless, none of the tested sanitizers are ideal for fungal inactivation at the concentration usually recommended and employed in the food industry.
Fei, TaoLeyva-Gutierrez, Francisco M. A.Wan, ZifanWang, Tong...
10页
查看更多>>摘要：We investigated the effect of salt, sugar, and hydrolyzed egg yolk protein (HEY) on yolk's rheological properties, thermal behavior, and microstructure for a better understanding of their gelation inhibition mechanism. Salted yolk samples had the highest yield stress, followed by HEY and sugared yolk samples. With the addition of salt, the yolk's denaturation temperature and amount of free water significantly increased. Conversely, sugar and HEY had no significant impact on the thermal behavior of yolk components. Different additives caused pronounced differences in yolk's microstructure. The addition of salt resulted in dissociation of proteins and a concomitant increase in the number of small particles. Sugar and HEY presumably interacted with proteins and rearranged them into stable clusters. Freezing time also impacted the rheological, thermal, and microstructural properties of yolk in the presence of the additives. With prolonged freezing time, the tendency to undergo gelation increased. The salted yolk sample had significantly increased amount of non-freezable water, while no changes were observed in sugared and HEY yolk samples. The size and clustering of the particles varied during prolonged freezing. Interestingly, frozen-thawed yolks with additives regained their fluidity during refrigeration. Overall, salt, sugar and HEY effectively inhibited gelation, albeit, through different mechanistic processes.
查看更多>>摘要：The bacterial community and predictive functionality of 51 traditional fermented dairy products (raw milk, yoghurt, fermented milk curd, wrum, milk silk-skin, butter, milk granule, koumiss, and cheese) from three countries (China, Inner Mongolia and Xinjiang; South Africa; Sri Lanka) were investigated and compared by highthroughput sequencing of 16S rRNA genes. Lactobacillus, Streptococcus, and Lactococcus were the major genera in raw milk, yoghurt, fermented milk curd, wrum, and milk silk-skin samples from Inner Mongolia, whereas the butter samples contained Rhodococcus and Pseudomonas. Lactobacillus was the main genus in yoghurt, milk granule, and koumiss samples from Xinjiang. Streptococcus was the predominant genus in yoghurt and cheese samples from South Africa and Sri Lanka. Streptococcus thermophilus was the dominant species in samples from South Africa and Sri Lanka, the prevalent species in samples from Xinjiang were Lactobacillus helveticus and Lactobacillus delbrueckii subsp. bulgaricus. The butter samples from Inner Mongolia were abundant in Rhodococcus erythropolis. Functional analysis demonstrated that Rhodococcus erythropolis and Lactobacillus helveticus play an important role in carbohydrate and lipid metabolism. In summary, mining the bacterial communities of different traditional fermented dairy products from different countries paves the way in the isolation of functional microorganisms and exploration of their functions.
Parvarei, Mitra MolaeeKhorshidian, NasimFazeli, Mohammad RezaMortazavian, Amir M....
11页
查看更多>>摘要：Paraprobiotic yogurts were produced using killed cells of Lactobacillus acidophilus ATCCSD 5221 and Bifidobacterium lactis BB-12. Fourier-Transform Infrared Spectroscopy (FTIR-ATR), as an important and sensitive method for detecting chemical bonds in dairy product, was used to specify the FTIR-ATR spectra and detect suitable spectral regions for probiotics as well as paraprobiotics (0-day). Principal Component Analysis (PCA) was employed to specify the spectra. In PCA, two principal components (PC1 with 37.07%, PC2 with 23/40%) were found with cumulative variance greater than 90%. The microstructure was tested using field emission scanning electron microscopy. Samples containing paraprobiotics, added before fermentation, showed a different structure compared to probiotic samples with more open and larger size of pores. Treatments containing probiotics and paraprobiotics added after fermentation revealed an open and loose structure as well as a more compact structure. In yogurt samples without probiotics and paraprobiotics, an open and spongy structure was observed. The sample containing killed cells of L. acidophilus ATCCSD 5221 and B. lactis BB-12 added before fermentation exhibited the lowest syneresis, highest water holding capacity, and highest apparent viscosity due to the presence of exopolysaccharides and cell components.
查看更多>>摘要：The functional activity of umami peptides after digestion is poorly known. We studied the dipeptidyl peptidase-4 (DPP- IV) and angiotensin I-converting enzyme (ACE) inhibition activity of 14 umami peptides from Ruditapes philippinarum in vivo and in vitro. GRVSNCAA (IC50 = 57.93 mu mol/L) and TYLPVH (IC50 = 1.37 mu mol/L) exhibited noncompetitive ACE inhibitory activity in vitro, and GPAGPAGPR showed DPP-IV inhibitory activity (IC50 = 160.5 mu mol/L). The peptides also decreased systolic blood pressure and reduced the blood sugar level in the oral glucose tolerance test and the single blood pressure test. To understand the hypoglycemic and hypotensive mechanism of peptides, we conducted cell experiments with HepG2 and human umbilical vein endothelial cells. GRVSNCAA and TYLPVH significantly (p < 0.01) promoted nitric oxide secretion and reduced endothelin-1 production. GPAGPAGPR exerted hypoglycemic activity by increasing the content of hexokinase and pyruvate kinase.These results suggest that some umami peptides have the potential to provide human health benefits.
查看更多>>摘要：Direct application of active and volatile compounds of essential oils (EOs) is ineffective in food and uncontrolled release of these compounds may be undesirable from sensory and antimicrobial efficacy standpoints. The present study aimed to develop and characterize the physical and antimicrobial properties of casting composite chitosan (CS) thin films laminated with electrospun nonwovens loaded with Zataria multiflora (ZEO) and cinnamon (CEO) targeting for active food packaging purposes. The composite structures were incorporated with various amounts of ZEO and CEO blend to enhance their antimicrobial and physical properties. There was no significant difference between antibacterial activity of the films containing EOs in both Gram-positive and Gram-negative bacteria (P'0.05). All the films had antifungal activity against A.flavus. The highest antioxidant activity was found in the composite CS film (97.20%) in comparison to other films (P'0.05). Morphological analysis of bilayer films revealed homogeneous bead-free electrospun nanofibers with diameters of less than 200 nm. The addition of 0.5 %v/v CEO significantly enhanced the elongation in comparison to CS film (P'0.05). Our results demonstrated that the properties of bilayer films were influenced by the contents of EOs and these findings may pave a way for introducing new category of active packaging staffs.
NSTL
Elsevier