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1.
The aim of this study was to use the process of osmotic dehydration to enrich banana slices with Lactobacillus rhamnosus encapsulated in a double emulsion. The effect of a pulsed vacuum and the concentration of the osmotic solution on the impregnation of the microorganism and on mass transfer during osmotic dehydration of the fruit were assessed. The kinetics of the water loss (WL), solid gain (SG) and water activity (aw) were obtained using an aqueous solution with 40, 50 and 60% sucrose with emulsion and a vacuum pulse of 50 mbar for 10 and 20 min at the beginning of the osmotic process. The high concentrations of sucrose in the osmotic solution, combined with the application of a pulsed vacuum, produced an increase in the rates of WL and SG of the osmodehydrated banana, as well as a reduction of its aw. L. rhamnosus survived at levels above 107 CFU/g in the hypertonic solution and in the osmodehydrated bananas. Scanning electron microscopy (SEM) showed that the encapsulated probiotic adheres to the banana’s surface, which demonstrates that double emulsions can be used to impregnate probiotics in vegetal tissues.  相似文献   

2.
The various extracts from chamdanggui (Angelica gigas Nakai) and sogdan (Phlomis umbrosa Turcz) were evaluated for estrogenic activity and characterized according to HPLC profile. Chamdanggui and sogdan were individually extracted with 4 solvents (hot water, 70% ethanol, n-butanol, and dichloromethane) of differing polarities. Estrogenic activity was determined by E-screen using an estrogen-dependent MCF-7 BUS cell. Although almost all extracts showed estrogenic effects in a concentrationdependent manner, the hot water extract from chamdanggui (250 μg/mL) had the higher effect (138%). Among 90 fractions using HPLC separation of the hot water extract from chamdanggui, fraction 21 and 28 produced the highest estrogenic effects of 178 and 163% at 10 μg/mL, respectively. The results imply that the hot water extract from chamdanggui could be useful as an alternative hormone replacement therapy.  相似文献   

3.
Beta vulgaris or beet root powder is a good natural food colorant since beet contains significant amount of red-colored betalain pigments. This paper reports the process optimization of drying conditions to get beet root powder with maximum retention of red color. Response surface method was used with three factors: five-level central composite design to arrive at optimum drying temperature, sample thickness, and hot air recirculation. Beet powder was evaluated to assess color retention with respect to fresh beet as a control. A 53 °C temperature and 7-mm thickness with 63% air recirculation ratio gave the best product, with 90% retention of red color having acceptable rehydration ratio and final moisture content. Using optimum sample thickness and air recirculation rate, drying process was further improved to reduce drying time and energy consumption. At different temperatures (50 to 120 °C), drying characteristics were studied. Thus, drying time of 6 h was further reduced to 4 h by applying sequential temperature gradient during drying (initial 120 °C gradually reduced to 53 °C) that also resulted in energy savings with the same degree of color retention.  相似文献   

4.
The aim of this paper was to study the biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermine and spermidine) production of selected technological important lactic acid bacteria (strains of the genera Lactococcus, Lactobacillus and Streptococcus). Three methods (ion-exchange chromatography (IEC), PCR and cultivation method with pH indicator) were used. Within the 39 strains of lactic acid bacteria tested, the production of tyramine (formed by tyrosine decarboxylase) was detected in eight strains (3 strains of Lactococcus lactis subsp. lactis, three strains of Lactococcus lactis subsp. cremoris, 1 strain of Streptococcus thermophilus and 1 strain of Lactobacillus delbrueckii subsp. bulgaricus). The other tested biogenic amines were not detected. Cultivation in decarboxylation broth seems to be the least accurate method for the detection of biogenic amines due to enhanced risk of false-positive reactions. Therefore, in order to detect bacteria producing biogenic amines, the combination of PCR and chromatographic methods (e.g. IEC) can be recommended.  相似文献   

5.
To acquire the effectiveness of oral treatments, aqueous extracts of Anodonta woodiana (HB) were incorporated into liposome and its antitumor activities evaluated in vivo. The HB-loaded liposomes (HBL) were prepared at a mean size of 14.85 μm by reverse-phase evaporation method. Referring to the maximum tolerated doses test, mice with orally administrated HBL, at a 3 g/kg body weight dosage, showed no obvious acute toxic sign. Furthermore, the tumoricidal activities of HBL against C26 murine colon carcinoma, Lewis lung tumor, human QGY hepatic carcinoma and MKN-45 gastric tumor were examined, respectively. In contrast to free HB, HBL possessed remarkable antitumor activity. Simultaneously, the effect of HBL was observed in a dose-dependent manner. For C26 murine colon carcinoma and Lewis lung tumor, the inhibitory ratios of HBL were 54.36 and 51.97% at a dose of 400 mg/kg, respectively. The suppression of tumor growth and the reduction in body weight were more pronounced in human QGY hepatic carcinoma and MKN-45 gastric tumors inoculated mice by treatment of HBL during 30 days. All these promising results implied that liposome-incorporated aqueous extracts of Anodonta woodiana had a more potential application as a natural antitumor and immunomodulator formulation.  相似文献   

6.
Osmotic dehydration (OD) is the most important procedure for obtaining candied wumei (Prunus mume), which is a very popular snack in Eastern Asian countries. This study aims to evaluate the effects of high hydrostatic pressure (HHP) pre-treatment (50–400 MPa) on the mass transfer kinetics and on the water diffusivity of wumei fruit during OD and to investigate the effect on water distribution and cell viability aspects. The results showed that HHP increased initial rate and effective diffusivity of mass transfer values compared to non-treated samples. Time domain nuclear magnetic resonance revealed that, upon HHP treatment, the water redistributed in vacuole, cytoplasm/extracellular spaces, and cell wall/membrane. The application of 400 MPa probably caused some irreversible damages to the cell membranes. The cell viability study determined by fluorescein diacetate staining showed a loss of cell viability at pressures higher than 200 MPa. HHP exhibited an effective pre-treatment to increase mass transfer of wumei fruit during OD process.  相似文献   

7.
The heavy metal contents and chemical compositions among mackerel species were investigated. Atlantic and chub mackerel had higher mercury, but lower lead than blue mackerel. Chub mackerel had the highest crude fat (18.62%) and the lowest moisture (58.29%), whereas blue mackerel had the highest moisture (70.10%) and the lowest crude fat (2.89%). Atlantic and blue mackerel had total saturated fatty acids (SFA)>polyunsaturated fatty acids (PUFA)>monounsaturated fatty acids (MUFA), whereas chub mackerel had PUFA>SFA>MUFA. The main SFA of the 3 mackerels were 16:0 and the main PUFAs were 22:6n-3 and 20:5n-3. The total amino acid contents in Atlantic, blue, and chub mackerel were 190.63, 169.49, and 172.97 mg/g, respectively. The major amino acids of the 3 mackerels were glutamic acid, aspartic acid, lysine, and leucine.  相似文献   

8.
The prevalence, genetic diversity, and antibiotic susceptibility of Cronobacter species (Enterobacter sakazakii) isolated from sunshik products, its ingredients, and root vegetable farm’s soils were investigated to analyze main reservoirs and contaminated sources of Cronobacter spp. Cronobacter spp. was isolated from 9 of 15 sunshik products, 26 of 72 its ingredients, and 2 of 39 soils. The root vegetables such as sweet potato and carrot showed higher contamination rate (70%) than the other sunshik ingredients. All isolates showed 929 bp band amplified from 16S rRNA and resistant to ampicillin, amoxicillin/clavulanic acid, and cefazolin. All isolates showed diverse random-amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) band patterns. However, 3 cases of RAPD banding patterns between clinical strains and isolates from sunshik products and root vegetables (yam, carrot) were related with similarities level of 80%. These studies indicated that root vegetables can be an important contamination source of Cronobacter spp. in sunshik products. Thus, the preparation of root vegetables for manufacturing sunshik products used as a weaning diet was handled with more care than the other sunshik ingredients.  相似文献   

9.
The survival curves of Escherichia coli and Listeria innocua inactivated by high hydrostatic pressure (HHP) were obtained at room temperature (∼22 °C) and at five pressure levels (400, 450, 500, 550 and 600 MPa) in whole milk. These curves were described by the Weibull model and parameters of this model were reduced from two to one with slight loss of goodness-of-fit. The logarithm of the time constant parameter (δ) of the reduced Weibull model was described with respect to high pressure (P). This approach can be used to define a z p value analogous to the modeling of the classical D value (increase in pressure that results in one log unit decrease of δ values). The development of accurate survival models under high pressure, as presented here, can be very beneficial to food industry for designing, evaluating and optimizing HHP processes as a new preservation technology.  相似文献   

10.
A new rapid method based on real-time PCR was developed to detect four thermophilic Campylobacter species (Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis) in food samples. The assay targeted the bipA gene for C. upsaliensis and C. lari, whereas the gene encoding the ATP-binding protein CJE0832 was used to detect C. coli and C. jejuni. These genes were chosen for this assay due to their low variability and mutation rate at a species level. The multiplex PCR showed 100% inclusivity for all 25 thermophilic Campylobacter strains tested and 100% exclusivity for 38 non-targeted strains belonging to closely related species. The newly developed real-time PCR could detect down to 102 genomes/reaction and displayed efficiency above 97% for all species except for C. upsaliensis (90.1%). The method proved to be a reliable tool for food analysis, showing 100% sensitivity, 96% efficiency, and 92.45% specificity when validated against the gold standard method UNE-EN ISO 10272:2006 using 200 diverse food samples (meat, fish, fruits and vegetables, and raw milk). In artificially spiked samples, the detection limit of the method was 10 cfu/g in salad, 5 cfu/g in turkey meat, and 1 cfu/g in the rest of meat samples tested. Consequently, the newly designed molecular tool represents a quick and safe alternative to obtain reliable results concerning the presence/absence of the main thermophilic Campylobacter in any food sample.  相似文献   

11.
Thermal inactivation of quality-related enzymes in both cauliflower crude enzyme extracts and fresh tissue samples was studied in temperature range 50–100 °C. For crude enzyme extracts, several parameters, reaction rate constants (k) and activation energy (E a) as well as decimal reduction time (D) and (z) values, were used to characterize the thermal stability. The rates of inactivation were found to follow first-order inactivation kinetics. Activation energies varied between 101.18 and 208.42 kJ mol−1 with z values of 10.59–24.09 °C. The examined kinetics indicated that lipoxygenase was the most heat resistant followed by peroxidase, polyphenol oxidase, pectin methyl esterase and ascorbic acid oxidase. Furthermore, the obtained results from the blanched fresh tissues indicated that inactivation of lipoxygenase secured disappearing of any other enzyme activities. Therefore, this study recommends using lipoxygenase as an indicator enzyme to optimize the thermal treatments of cauliflower products.  相似文献   

12.
Fish protein hydrolysates (FPHs) were prepared from freshwater carps (Catla catla, Labeo rohita, and Cirrhinus mrigala) using flavorzyme at different degrees of hydrolysis (DHs) ranging from 5 to 20%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activity of the FPHs prepared from the three species were in the range of 50–82%; the ferric reducing power of the FPHs prepared from catla was the highest. The linoleic acid peroxidation inhibition activity of the prepared FPHs varied from 71 to 91%. The emulsion activity index of the FPHs prepared from catla and rohu decreased significantly with an increase in the DH (p < 0.05). The emulsion stability index of the FPHs prepared from the three species was the highest at 20% DH. FPHs prepared from freshwater carps possess good antioxidant and surface-active properties and are therefore suitable to be used as natural antioxidants in health-food formulation and as water-soluble antioxidants in the food-processing industry.  相似文献   

13.
Four types of meju were made from 100%(w/w) defatted soybean (DFS), a mixture of 80%(w/w) defatted soybean, and 20%(w/w) glasswort (DFS-G), a mixture of 80%(w/w) defatted soybean and 20%(w/w) rice (DFS-R), and a mixture of 60%(w/w) defatted soybean, 20%(w/w) glasswort, and 20%(w/w) rice (DFS-GR). Four types of Korean traditional soy sauce were prepared from the 4 types of meju. Mineral and antioxidant contents in the soy sauce made of DFS-G and DFS-GR were significantly higher than others. Citric, malic, succinic, lactic, and pyroglutamic acid contents in soy sauce made of DFS-R and DFS-GR were 1.3–1.5 times higher than others. Total nitrogen and free amino acid contents in soy sauce were correlated with DFS concentration in the meju. The bacterial community in the non-fermented meju-making ingredients was replaced largely by Bacillus sp. in the fermented meju. The use of glasswort and rice in the meju-making process did not alter the bacterial community responsible for the fermentation of meju.  相似文献   

14.
This study aimed to assess the effect of sous vide cooking on the total and resistant starch content, color, and shear force in three potato cultivars (Agria, Agata, and Carrera). Potato strips were also cooked by three common treatments (boiling, frying, and microwaving) to evaluate the differences between the methods. According to principal component analysis (PCA), sous vide-processed cv. Agria and Agata potato strips were grouped with boiled samples, in contrast, cv. Carrera sous vide samples were grouped with microwaved samples. Higher water losses were associated with microwaved potatoes due to the diffusion of water inside the tuber. In addition, a significant decrease in shear force was obtained after microwaving and sous vide cooking (p < 0.05) irrespective of the treatment strength. The three cultivars became less bright, and the intensity of the color decreased; however, variations in the cook value (C 100, min) between treatments did not affect the lightness and hue angle. Regardless of the initial value of resistant starch and the intensity of the cooking process, all of the cultivars reached a final content of less than 5%. From our results, in-pack sterilization may be considered for application in the food industry as a technology that has a similar impact to conventional cooking treatments used on potato products.  相似文献   

15.
The aim of this research was to investigate the levels of phenolic compounds and antioxidant activities in different tissues including leaves, stems, and roots from baekseohyang (Daphne kiusiana). The highest contents of total phenolics (43.59 mg gallic acid equivalent, GAE/g) and flavonoids (15.73 mg rutin equivalents, RE/g) were observed in the 75% methanol extract of leaves. Moreover, this extract had the predominant antioxidant capacity, DPPH (85.91%) and ABTS (92.57%) radical scavenging activities as well as reducing power (7.20%) at a concentration of 5 mg/mL. The highest content of phenolic compounds was also exhibited in this extract with an increasing order in leaves, roots, and stems and their major components were vanillic acid (6.37 mg/g), tannic acid (1.91 mg/g), and p-hydroxybenzoic acid (3.96 mg/g). Thus, the strong antioxidant activities of the 75% methanol extract are correlated with high phenolic compound contents. This study suggests that baekseohyang leaves may potentially be used as an accessible source of natural antioxidants.  相似文献   

16.
Food allergy has becoming the serious threat in the world for which the search of an effective anti-allergic drug is the demand of time. Keeping in view of the potentiality of seaweeds, the ethanol extracts from Sargassum tenerrimum (ST), Sargassum cervicorne (SC), and Sargassum graminifolium turn (SG) have been studied in vivo for its antiallergenicity through passive cutaneous anaphylaxis (PCA) and active cutaneous anaphylaxis (ACA) in female BALB/c mice. Intraperitoneal administration of these ethanol extracts inhibit mouse PCA and ACA in a dose-dependent manner using ovalbumin (OVA) and shrimp allergen as triggering agents to induce allergenicity over mice. The extract of ST containing phlorotannin has been found most active over the suppression of PCA triggered by OVA and shrimp with IC50 values of 25.64 and 40.98 mg/kg, respectively and an efficacy comparable to that of an anti-allergic drug disodiumcromoglycate. Similarly, ST inhibits ACA triggered by ova and shrimp allergen in the mouse, with 50% suppression at 25.5 and 43.53 mg/kg, respectively. The results presented here show that these extracts are active on the studied models among which ethanol extract of ST was the most potent, leading toward the promising development of a new class of anti-allergic drugs.  相似文献   

17.
The diversity of 87 Lactobacillus paracasei and Lactobacillus plantarum/paraplantarum strains, previously identified from different autochthonous dairy products, was investigated by phenotypic and genotypic approaches. The increased resolution obtained using phenotypic and genotypic characterization allowed the level of strain heterogeneity detection to be widened. Phenotypic diversity was evaluated by studying biochemical characteristics of technological interest, including antimicrobial and proteinase activities, resistance to nisin, aggregation ability, production of exopolysaccharides, acetoin and diacetyl, citrate utilization, and antibiotic susceptibility. Genotypic diversity was generally evaluated by PCR amplification of repetitive bacterial DNA element fingerprinting using the (GTG)5 primer [(GTG)5-PCR]. Moreover, in cases where strains were not discriminated by (GTG)5-PCR combined with phenotypic analysis, pulsed-field gel electrophoresis (PFGE) analysis was performed. The results indicate that L. plantarum/paraplantarum and L. paracasei natural isolates from artisanal dairy products are a gold mine in terms of diversity of strains and could be potentially interesting to dairy companies for the formulation of functional starter cultures in the production of innovative foods.  相似文献   

18.
Isotherms of shiitake mushroom (Lentinus edodes) at 25 and 40°C were determined and drying kinetics of whole and sliced shiitake mushrooms were tested using a convective air drying method at different drying temperature of 40, 50, 60, and 70°C. The monolayer moisture contents of the mushroom were 7.23 and 5.44 g water/100 g of dry solids at 25 and 40°C, respectively. Both mushroom samples showed falling drying rate periods with increasing drying rates with increases in drying temperature, and the drying rate of the sliced mushrooms was faster than that of the whole mushrooms at the same drying conditions. The kinetic parameters for dehydration of the mushrooms were determined using the Newton model and the Classical diffusion model. Activation energy (E a ) values as determined using the Newton model were 22.58 and 20.48 kJ/mol for the whole and sliced mushrooms, respectively.  相似文献   

19.
‘Lemon Myrtle’ is becoming increasingly popular in Europe both for use in cuisine and phytotherapy. However, this common name covers two completely different species, Backhousia citriodora F. Muell. and Leptospermum citratum Challinor, Cheel & A.R.Penfold. These species differ with respect to secondary compounds and even can cause, if mixed up and applied in high dose, toxic effects. We describe how the two species can be discriminated microscopically making use of differences in the morphology of leaf pavement cells and the relative size of palisade parenchyma. Based on the large subunit of ribulose-1,5-bisphosphate carboxylase oxygenase (rbcL) as molecular marker, the phylogenetic position of the two species within the Myrtaceae could be clarified. This sequence information was used to develop a simple assay to discriminate the two species even in dried and highly fragmented mixtures as typically occurring in commercial samples. This assay utilises the occurrence of single-nucleotide exchanges between those species that produce different fragments when the rbcL amplificates are restricted with Sac II.  相似文献   

20.
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