Showing papers in "Lwt - Food Science and Technology in 2017"
TL;DR: Investigation of probiotic characteristics and fermentation profile of selected lactic acid bacteria isolated from raw camel milk found that among the isolates, Lactococcus lactis KX881768, LACTobacillus plantarum KX 881772, L lactococcus latis K X881782 and Lactobacillian exhibited remarkable cholesterol removal abilities and very promising fermentation profiles.
Abstract: The aim of this study was to investigate probiotic characteristics and fermentation profile of selected lactic acid bacteria isolated from raw camel milk. Physiological properties, cell surface properties (hydrophobicity, autoaggregation, co-aggregation), acid and bile tolerance, bile salt hydrolysis, cholesterol removing, exopolysaccharide (EPS) production, hemolytic and antimicrobial activities, resistance toward lysozyme and six antibiotics, and fermentation profile (growth, pH, and proteolysis) were examined. 16S rRNA sequencing was carried out to identify six presumptive LAB isolates. In general, all identified LAB (Lactococcus lactis KX881768, Lactobacillus plantarum KX881772, Lactococcus lactis KX881782 and Lactobacillus plantarum KX881779) showed auto-aggregation ability, high cholesterol removal ability, high co-aggregation, strong antimicrobial activity and EPS production. Among the isolates, Lactococcus lactis KX881768, Lactobacillus plantarum KX881772, Lactococcus lactis KX881782 and Lactobacillus plantarum KX881779 exhibited remarkable cholesterol removal abilities. Similarly, Lactobacillus plantarum KX881779, and Lactococcus lactis KX881782 showed very promising fermentation profiles.
222 citations
TL;DR: In this article, pH-sensitive films were developed from solvent casting of polymer solutions containing corn starch, glycerol, and anthocyanin extract (from red cabbage or black bean) prepared at pH 5.
Abstract: The aim of this study was to develop pH-sensitive films based on corn starch and anthocyanins extracted from black bean seed coat and red cabbage. The pH-sensitive films were developed from solvent casting of polymer solutions containing corn starch, glycerol, and anthocyanin extract (from red cabbage or black bean) prepared at pH 5. The color of films changed from pink to purple and blue, as a function of the pH. The pH-sensitive films were evaluated by their morphological, chemical, physical, mechanical and thermal properties. In addition, the stability was evaluated during 28 days of storage (presence and absence of light; with and without cooling). The pH-sensitive films with red cabbage anthocyanins showed a higher stability than that with black bean anthocyanins when stored at room temperature and exposed to light. Both pH-sensitive films exhibited greater color stability when stored under refrigeration as compared to storage at room temperature.
207 citations
TL;DR: In this paper, the nano-emulsions of essential oils (rosemary, laurel, thyme and sage) were used to preserve the organoleptic quality of rainbow trout.
Abstract: Antimicrobial and antioxidant effects of nanoemulsions containing herb oils (rosemary, laurel, thyme and sage) on the quality of rainbow trout were investigated. Fish fillets were immersed for 3 min in the nanoemulsions prepared with different oils. During 24 days of storage, sensory (raw and cooked), chemical (TBA (thiobarbituric acid), pH, TVB-N (total volatile basic nitrogen), PV (peroxide value), FFA (free fatty acids)) and microbiological quality (total mesophilic aerobic and psychrophilic aerobic bacteria, Enterobacteriaceae count) of rainbow trout fillets in ice at 2 ± 2 °C were carried out. Nanoemulsions of essential oils enhanced organoleptic quality of rainbow trout. Shelf life of rainbow trout was found as 14 days for the control, 17 days for the treatment groups. The use of nanoemulsions based on all essential oils reduced the values of the biochemical parameters and slowed down the growth of bacteria. TVB-N values were lower in all samples than limit value. FFA and PV developed at a slower rate in the treated groups, especially in the rosemary group. The lowest bacterial numbers were obtained from rosemary followed by thyme group. Among the essential oils, it can be concluded that rosemary and thyme can be recommended for nanoemulsion as a preservative for fish fillets.
173 citations
TL;DR: In this paper, a novel ACE inhibitory peptide named F2-a was identified by Quardrupole Time-of-flight Mass Spectrometer (Q-TOF-MS) with an electro-spray ionization (ESI) source.
Abstract: Rice bran protein was hydrolyzed using trypsin. The hydrolysate (RBPH) was then further separated by membrane bioreactor system, gel filtration and reversed phase high-performance liquid chromatography (RP-HPLC). A novel antioxidant and angiotensin I-converting enzyme (ACE) inhibitory peptide named as F2-a, which exhibited high DPPH free radicals scavenging activity, reducing power and ACE inhibitory activity (IC50 of 76 μM) was isolated. The amino acid sequence, Tyr-Ser-Lys (Mw: 395.0 Da), was identified by Quardrupole Time-of-flight Mass Spectrometer (Q-TOF-MS) with an electro-spray ionization (ESI) source. The molecular docking study revealed that the ACE inhibition of Tyr-Ser-Lys was mainly attributed to forming very strong hydrogen bonds with the active pockets of human ACE. These results indicate that rice bran is a potential source of bioactive peptides possessing antioxidant and ACE inhibitory activities.
172 citations
TL;DR: In this paper, the incorporation of lime essential oil into chitosan nanoparticles and nanocapsules and the study of their enhancing effect on antibacterial activity was shown.
Abstract: Lime oil has recognized fungicidal and antibacterial properties. Nanoparticles and nanocapsules are structures that have been developed to overcome the high volatility of essential oils. Chitosan nanoparticles and chitosan nanocapsules incorporated with lime essential oil were synthesized by nanoprecipitation and nanoencapsulation methods, respectively. The samples were characterized by transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR), and Z potential was measured. Also, particle size distribution was analyzed by dynamic light scattering (DLS) and the antibacterial activity was studied. According to TEM, the average size of nanocapsules was higher than for nanoparticles. When lime essential oil was incorporated, the particle size increased. Lime essential oil incorporation was evidenced by FTIR. Chitosan nanocapsules showed higher Z potential value compared to chitosan nanoparticles. The antibacterial activity was tested against four food-borne pathogens, being higher for nanoparticles than for nanocapsules. The highest antibacterial activity was observed for chitosan nanoparticles incorporated with lime essential oil applied against Shigella dysenteriae, attaining an inhibition halo (IH) value of 3.5 cm for 40 μL of minimum inhibitory volume (MIV). The novelty of incorporating lime essential oil into chitosan nanoparticles and nanocapsules and the study of their enhancing effect on antibacterial activity are shown in this paper.
159 citations
TL;DR: Using cellulase, xylanase, and ball-milling, the influences of enzyme and enzyme-micronization treatments on the structural and functional properties of rice bran dietary fiber (RBDF) were investigated as discussed by the authors.
Abstract: Using cellulase, xylanase, and ball-milling, the influences of enzyme and enzyme-micronization treatments on the structural and functional properties of rice bran dietary fiber (RBDF) were investigated. Due to the degradation of insoluble dietary fiber, the cellulase, xylanase, micronization, combined enzymes, and enzyme-micronization treatments increased the soluble dietary fiber content by 3.8, 4.7, 3.5, 10.0, and 11.4 fold, respectively. Scanning electron microscopy analysis indicated the enzymatic treatments caused the breakage of RBDF structure, and the enzyme-micronization treatment totally broke the RBDF matrix. Cellulase and xylanase increased RBDF crystallinity because of the hydrolysis of hemicellulose and the amorphous portion in cellulose, while enzyme-micronization reduced RBDF crystallinity due to the destruction of crystalline structure. Infrared spectroscopy indicated the breakage of intra-molecular hydrogen bonding and increased oligosaccharides, and differential scanning calorimetry analysis showed the oligosaccharides melting and reduced water-evaporating peaks because of the enzymatic and enzyme-micronization treatments. Additionally, enzyme and enzyme-micronization reduced the water and oil holding capacity, but increased the swelling capacity, cholesterol and sodium taurocholate absorption capacity of RBDF. The results suggest that cellulase and xylanase can modify the structural and functional attributes of RBDF, and the enzymatic treatments assisted with micronization is more effective in modifying the RBDF properties.
157 citations
TL;DR: Pediococcus pentosaceus and Staphylococcus xylosus were evaluated to determine their roles in the lipolysis and lipid oxidation in Harbin dry sausages and their relation to flavour development as mentioned in this paper.
Abstract: Pediococcus pentosaceus, Lactobacillus curvatus, Lactobacillus sakei and Staphylococcus xylosus were evaluated to determine their roles in the lipolysis and lipid oxidation in Harbin dry sausages and their relation to flavour development. The free fatty acid (FFA) contents of both muscle and fat tissues were higher in the inoculated sausages than those of the non-inoculated control, especially with mixed strains (P
157 citations
TL;DR: In this paper, a mixture of blended cloves/cinnamon essential oil nanoemulsions was used to develop a natural antimicrobial agent in food industry, and the nanoemulsion showed higher antimicrobial activity against four tested microorganisms of Escherichia coli, Bacillus subtilis, Salmonella typhimurium, and Staphylococcus aureus.
Abstract: Blended cloves/cinnamon essential oil nanoemulsions were prepared using Tween 80 and ethanol as surfactant and cosurfactant respectively. The preparation process was optimized via a pseudo-ternary phase diagram. The nanoemulsion showed a steady state with an average particle size of 8.69 nm under the surfactant to cosurfactant ratio (Km) of 3:1 and oil to the mixed surfactant/cosurfactant ratio of 1:9. The nanoemulsion was stable after centrifuging at 10,000 rpm for 20 min, stored at 60 °C for 1 month, or even heated at 80 °C for 30 min, respectively. Compared with the non-nanoemulsion counterparts, the nanoemulsion showed higher antimicrobial activity against four tested microorganisms of Escherichia coli, Bacillus subtilis, Salmonella typhimurium, and Staphylococcus aureus, even at far lower concentrations. Furthermore, the addition of the cloves/cinnamon nanoemulsion in a model food of mushroom sauce did not alter its major flavor, except offered some attractive fragrant flavors. This research suggested that the blended cloves/cinnamon essential oil nanoemulsions have the potential to be developed as a natural antimicrobial agent in food industry.
142 citations
TL;DR: In this article, two products prepared from an anthocyanin-rich extract of a blackberry byproduct through freeze-drying Maltodextrins with 10 and 20 dextrose equivalent (DE) were assessed as the carrier matrices.
Abstract: One approach to improving sustainable food production is to add value to fruit by-products, which are currently used as animal feed or discarded, yet may be useful sources of natural antioxidants due to their phenolic compounds Hence, the present work aimed to produce and evaluate two products prepared from an anthocyanin-rich extract of a blackberry by-product through freeze-drying Maltodextrins with 10 and 20 dextrose equivalent (DE), were assessed as the carrier matrices The maltodextrin DE did not significantly influence the mean diameter and solubility of the particles Morphological analysis revealed that all the particles exhibited a broken glass structure and shriveled surfaces Comparatively, better results were obtained from the maltodextrin 10 than 20DE powders, regarding anthocyanin retention in the drying process, hygroscopicity, moisture content, acidity, water activity and color indices (P
136 citations
TL;DR: In this paper, after incorporating Spirulina into yogurt at four different concentrations (0.25, 0.5, 0.75 and 1%), the authors studied its effect on the fermentation process, texture, nutraceutical and sensory characteristics of yogurt.
Abstract: Due to the high consumption rate of fermented milk products such as yogurt, the fortification of these products will effectively reduce diseases associated with nutritional deficiencies. In the present study, after incorporating Spirulina into yogurt at four different concentrations (0.25, 0.5, 0.75 and 1%), we studied its effect on the fermentation process, texture, nutraceutical and sensory characteristics of yogurt. The addition of 0.25% of Spirulina was significantly sufficient to accelerate the end of fermentation (p < 0.05) and conserve the textural properties and sensory acceptability of the final milk product. This treatment also exhibited significant better water holding capacity and lower whey syneresis during 28 days of storage. During this period, the colored yogurt showed negligible variations for the L*, a* and b* indices, reflecting the strong stability of Spirulina color. Thanks to its high content in pigments, Spirulina considerably improve the antioxidant activity of the new formulated yogurt. Overall, it can be concluded that Spirulina can be used as a natural ingredient to develop a novel yogurt with high nutritional properties.
136 citations
TL;DR: In this article, the effects of the application of indirect cold plasma treatment on vitamin C, polyphenol and flavonoid contents, antioxidant activity (FRAP, DPPH, ABTS) and sucrose, fructose and glucose contents of cashew apple juice (Anacardium occidentale L) have been studied.
Abstract: The effects of the application of indirect cold plasma treatment on vitamin C, polyphenol and flavonoid contents, antioxidant activity (FRAP, DPPH, ABTS) and sucrose, fructose and glucose contents of cashew apple juice (Anacardium occidentale L) have been studied. Treatments were carried out by using a benchtop plasma system and two operative variables were considered: N2 plasma flow rate (10, 30 and 50 mL/min) and treatment time (5, 10 and 15 min). The plasma treatment promoted an increment of the vitamin C, flavonoid and polyphenol content as well on the antioxidant activity. Overexposure to plasma resulted in a decrease of most bioactive compounds denoting the importance in optimizing the process conditions.
TL;DR: In this article, the authors compared four different drying methods: hot air drying (AD), freeze drying (FD), microwave vacuum drying (MVD), and hot air-drying combined with microwave vacuum-diving (AD-MVD) for functional okra snacks.
Abstract: This study evaluated freeze drying combined with microwave vacuum drying (FD-MVD) for functional okra snacks. FD-MVD was compared using four different drying methods: hot air drying (AD), freeze drying (FD), microwave vacuum drying (MVD), and hot air drying combined with microwave vacuum drying (AD-MVD). For main antioxidant components including epigallocatechin gallate (EGC), epicatechin gallate (EGCG), epigallocatechin (ECG), quercetin 3-O-diglucoside, and quercetin 3-O-(malonyl) and antioxidant properties (IC50, AEAC, FRAP, ABTS, TF, and TPC) and color (L*, a*, and b*), the values of FD-MVD were similar to those of FD and significantly higher than those of AD, MVD, and AD-MVD (P
TL;DR: In this article, the effects of different blanching methods on weight loss, enzyme inactivation (peroxidase, POD, and polyphenol oxidase), characteristic bioactive component contents (red pigments and ascorbic acid), antioxidant capacity (total antioxidant activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity), ultrastructure and drying kinetics of red bell peppers under different blancing conditions were investiaged.
Abstract: The effects of hot water blanching (HWB), microwave blanching (MWB), infrared blanching (IRB) and high-humidity hot air impingement blanching (HHAIB) on weight loss, enzyme inactivation (peroxidase, POD and polyphenol oxidase, PPO), characteristic bioactive component contents (red pigments and ascorbic acid), antioxidant capacity (total antioxidant activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity), ultrastructure and drying kinetics of red bell peppers under different blanching conditions were investiaged. Results showed that the MWB and IRB treatment yielded lower weight loss than HWB and HHAIB. The inactivation of both PPO and POD enzymes was strongly dependent on blanching temperature and duration and microwave power for microwave blanching. The peppers treated by MWB, IRB, and HHAIB obtained higher red pigments and ascorbic acid retention, total antioxidant activity and DPPH values compared with the samples blanched by HWB. Ultrastructure analysis verified the difference phytochemical contents among four treatments. All four blanching treatments enhanced the drying kinetics relative to unblanched peppers. The Weibull distribution model was employed to calculate the moisture effective diffusivity (Deff), which ranged from 1.2688 × 10−10 to 2.8754 × 10−10 m2/s. The current findings not only contribute to a better understanding of different blanching methods but also provide more data and information for selecting blanching technologies.
TL;DR: The results of these tests indicate that the lactic acid bacteria isolated from human milk have excellent potential for use as probiotics in various products.
Abstract: Breast milk is a source of lactic acid bacteria with remarkable functional and Technological properties; it is also a potential source of probiotics. In the present study, seven strains of Lactobacillus rhamnosus were isolated from breast milk and identified according to their 16S rDNA sequences. Furthermore, their probiotic potential was evaluated. The probiotic properties were tested for aspects of antibiotic susceptibility, antimicrobial activity, lysozyme tolerance, gut condition tolerance (low pH, bile salt tolerance, and 0.4% phenol resistance), hydrophobicity, antioxidant ability, aggregation ability, and adhesion to Caco-2. Most isolates were resistant to Streptomycin, Ampicillin, Gentamicin, Kanamycin, Penicillin, Cephalotoxin, and Ciprofloxacin. The isolate shows a strong ability to adhere to Caco-2 cells as well as DPPH radical scavenging activity in the range of 76%–85%. Isolates SHA113 and SHA117 showed a high survival rate under gastrointestinal tract conditions (>80%), indicating excellent potential for application as probiotics. The results of these tests indicate that the lactic acid bacteria isolated from human milk have excellent potential for use as probiotics in various products.
TL;DR: In this paper, changes in structural characteristics and physicochemical properties of okara insoluble dietary fiber (IDF) during high-energy wet media milling process were analyzed, and the particle size of the IDF was effectively reduced from 66.7μm to 544.3nm after 6h of milling and kept constant (p < 0.05) as the milling procedure prolonged.
Abstract: Changes in structural characteristics and physicochemical properties of okara insoluble dietary fiber (IDF) during high-energy wet media milling process were analyzed. Particle size of the IDF was effectively reduced from 66.7 μm to 544.3 nm after 6 h of milling and kept constant (p > 0.05) as the milling process prolonged. As the particle size decreased, lightness and whiteness of the IDF significantly (p
TL;DR: In this paper, a facile electrostatic deposition method was proposed to encapsulate quercetin within chitosan/lecithin polymeric nanocapsules, with the aim of protecting quercetoin against degradation and enhancing its biocompatibility.
Abstract: A facile electrostatic deposition method was proposed to encapsulate quercetin within chitosan/lecithin polymeric nanocapsules, with the aim to protect quercetin against degradation and enhance its biocompatibility. Quercetin loaded polymeric nanocapsules (Q-NPs) were characterized in terms of size, morphology, encapsulation efficiency, storage stability, anti-oxidant and anti-proliferative activities. The obtained homogeneous and spherical Q-NPs have small particle size and high encapsulation efficiency (71.14%). The storage stability and antioxidant activity was improved compared with native quercetin. MTT assay and trypan blue exclusion assay showed the inhibitory effect of Q-NPs on HepG2 cells were comparable with that of free quercetin. This novel nanocapsule may provide a new system for the protection and delivery of a range of hydrophobic chemicals in vivo and food products.
TL;DR: In this article, the nanoemulsion of essential oil from Citrus medica L. var. sarcodactylis was prepared using a spontaneous emulsification method, which significantly enhanced the antioxidant, antibacterial and antibiofilm activity/efficiency of essential oils.
Abstract: In this work, the nanoemulsion of essential oil from Citrus medica L. var. sarcodactylis was prepared using a spontaneous emulsification method. Meanwhile, the effect of nanoemulsification on the antioxidant, antibacterial and antibiofilm activity of essential oil was evaluated. GC–MS analysis indicated nineteen compounds in the essential oil, and the essential oil was dominated by d -Limonene (50.04%). The minimum and stable droplets (73 nm) of essential oil nanoemulsion were formulated when the concentration of essential oil in oil phase was 50% (w/w). The hydroxyl radicals, DPPH radicals scavenging ability, iron reducing power, antibacterial and antibiofilm activity of nanoemulsified essential oil were significantly higher than those of pure essential oil at same concentration. Moreover, the nanoemulsified essential oil exhibited higher inhibitive effect on the bacteria in tofu than pure essential oil. Therefore, nanoemulsification significantly enhanced the antioxidant, antibacterial and antibiofilm activity/efficiency of essential oils, which will promote the abroad utilization of essential oils.
TL;DR: In this paper, the physicochemical properties of NGC nanoparticles and anti-listeria activities of poly-γ-glutamic acid/chitosan nanoparticles-embedded polyethylene oxide nanofibers on cheese were investigated.
Abstract: Listeria monocytogenes (L. monocytogenes) contamination in cheese production has received increasing attention. In order to inhibit the multiplication of the bacteria, the polyethylene oxide nanofibers containing nisin-loaded poly-γ-glutamic acid/chitosan (NGC) nanoparticles were engineered in this study. The physicochemical properties of NGC nanoparticles and anti-listeria activities of NGC nanoparticles-embedded polyethylene oxide nanofibers on cheese were investigated. The results indicated that NGC nanoparticles at 5 mg/mL of nisin had desirable polydispersity, zeta potential, encapsulation efficiency and load capacity. NGC nanoparticles-embedded polyethylene oxide nanofibers displayed satisfactory antibacterial activity against L. monocytogenes on cheese, without impact on the sensory quality. Therefore, the polyethylene oxide nanofibers containing NGC nanoparticles could be a promising active packaging for food preservation.
TL;DR: In this article, the authors investigated complex coacervation of soy protein isolate (SPI) with chitosan (CS) and the microencapsulation of algal oil using the SPI-CS coacervate.
Abstract: Complex coacervation of soy protein isolate (SPI) with chitosan (CS) and the microencapsulation of algal oil using the SPI-CS coacervate were investigated. The ζ -potential and coacervate yield data showed that the optimal complexation pH and CS/SPI ratio were 6.0 and 0.125 g g −1 , respectively. Isothermal titration calorimetry further confirmed that per molecule of SPI was saturated with 0.104 molecules of CS at pH 6.0, suggesting this binding was high affinity (Ka = 4.16 × 10 5 ± 0.09 × 10 5 M −1 ) and driven by both entropy and enthalpy. The rheological and microstructure measurement indicated that the SPI-CS coacervates had a viscoelastic solid behavior (G′ > G″) with highly interconnected gel-like network structures. The algal oil microcapsule fabricated by the SPI-CS coacervate showed advanced encapsulation efficiency and improved oxidative stability compared to the one encapsulated by SPI alone. The transglutaminase cross-linking could further improved the oxidative stability of SPI-CS microcapsule which proved by the reduced lipid hydroperoxides and volatile hexanal. This improvement was believed to be attributed to the antioxidant properties of CS as well as the increase of protection against oxidation by providing an oxygen barrier after complex coacervation and cross-linking.
TL;DR: The nanoemulsions exhibited good antibacterial action demonstrated by the low values in Vitro for minimum inhibitory concentration (0.56 and 0.60 mg oregano EO/mL for Staphylococcus aureus and Escherichia coli, respectively) and for minimum bactericidal concentration, 0.90 and 3.32 mg EO, respectively as mentioned in this paper.
Abstract: Several essential oils (EO) are efficient inhibitors of foodborne pathogen growth. However, their direct incorporation into food presents technological challenges, because of the possibility of extreme changes to their sensory properties. Such drawbacks can be overcome by encapsulation techniques, such as nanoemulsification. This study produced nanoemulsions encapsulating different amounts of oregano (Origanum vulgare) EO, using the phase inversion temperature method, and their physicochemical stability and antibacterial activity were evaluated. The average droplet diameters of the nanoemulsions were in the range of 35–55 nm, and nanoemulsions containing 5 g EO/100 g nanoemulsion were the most stable over the storage period of 45 days. The nanoemulsions exhibited good antibacterial action demonstrated by the low values in vitro for minimum inhibitory concentration (0.56 and 0.60 mg oregano EO/mL for Staphylococcus aureus and Escherichia coli, respectively, and for minimum bactericidal concentration, 0.90 and 3.32 mg oregano EO/mL for Staphylococcus aureus and Escherichia coli, respectively). The nanodispersions also had a higher antibacterial effect against E. coli than for S. aureus. The incorporation of nanoemulsions in chicken pâte did not change the physicochemical characteristics of the meat product. Therefore, the results obtained indicated that nanoemulsions encapsulating oregano EO are suitable to be incorporated into food formulations, such as chicken pâte, to prevent and control microbial growth and to extend their shelf life.
TL;DR: Curcumin in combination with a blue LED is a potential candidate for PDI against Gram positive and Gram negative bacteria.
Abstract: The present study evaluated the efficacy of photodynamic inactivation (PDI) of foodborne and spoilage bacteria using curcumin and a blue light emitting diode (LED). Curcumin at 75 μM was used to photo-irradiate Staphylococcus aureus ATCC 25923, Aeromonas hydrophila ATCC 7966, Salmonella Typhimurium ATCC 14028, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 at light doses of 139 J/cm2, 278 J/cm2 and 417 J/cm2. The cytotoxicity of curcumin in VERO cells was evaluated in similar conditions to bacterial photoinactivation assay, and the percentage of cell destruction was ≅ 13 ± 0.05%, for all light doses. Curcumin-mediated PDI of S. aureus induced a significant reduction of approximately 3.50 log CFU/ml at 139 J/cm2 and 278 J/cm2. Full inactivation was observed at 417 J/cm2. Among Gram negative bacteria, P. aeruginosa was the least susceptible to PDI, which counts were not significantly reduced. A significant reduction in E. coli counts was observed at 278 J/cm2, and no viable cells were detected after light exposure at 417 J/cm2. When photo-irradiated with curcumin at 278 J/cm2 and 417 J/cm2, A. hydrophila was completely eradicated, while a significant decrease (3.33log CFU/ml) was observed in bacterial counts at 139 J/cm2. Curcumin in combination with a blue LED is a potential candidate for PDI against Gram positive and Gram negative bacteria.
TL;DR: In this article, three classification strategies have been applied: (i) one input-class (1iC) classification, (ii) two inputclass (2iC), and (iii) pseudo two-class classification (p 2iC).
Abstract: Samples of olive oils (n = 67) from different qualities and samples of other vegetable edible oils (including soybean, sunflower, rapeseed, corn oil etc; n = 79) were used in this study as pure oils. Previous to spectroscopy analysis, a transesterification step was applied to the pure vegetable oil samples and all the different oil blends were then prepared to create in-house blended samples. Spectral acquisition was performed with typical parameters to collect the FTIR and Raman fingerprints. For the olive/non-olive classification model, three classification strategies have been applied: (i) one input-class (1iC) classification; (ii) two input-class (2iC) classification; and (iii) one input-class plus one 'dummy' class classification (or pseudo two input-class ( p 2iC) classification). The multivariate classification methods used were k-nearest neighbours (kNN), partial least squared-discriminant analysis (PLS-DA), one-class partial least squares (OCPLS), support vector machine classification (SVM-C), and soft independent modelling of class analogies (SIMCA). The multivariate quantification method used was partial least square-regression (PLS-R). FTIR fingerprints showed excellent classification ability to distinguish pure olive from non-olive oil. When PLS-DA or SVM-C techniques are applied, 100% of olive oil samples and 92% of other vegetable edible oils are correctly classified. In general FTIR fingerprints were more discriminative than Raman's in both classification and regression scenarios.
TL;DR: Results from this work highlight the influence of illumination condition on chia oil oxidative stability, suggesting that this oil should be stored in containers with light-barrier properties, and probably added to the antioxidants examined in the current study.
Abstract: The chia seed ( Salvia hispanica L.) is globally popular and valued for its nutritional and health attributes. Chia oil is mainly composed of triglycerides, in which polyunsaturated fatty acids (PUFAs, linoleic and α-linolenic acids) are found in high amounts. Although it seems evident that such fatty acid composition is favorable from a nutritional point of view, a higher content of linoleic and linolenic acids results in poorer oxidative stability and shorter shelf life of the oil. The aim of this study was to evaluate the combined effects of the storage condition (300 days under fluorescent light - 800 Lux - or in the dark, both at room temperature) with the addition of natural antioxidants (rosemary extract, RE; tocopherol, TOC; ascorbyl palmitate, AP). In the dark, the combined addition of AP and TOC significantly reduced lipid oxidation and improved oil shelf life. Moreover, this combination maintained an acceptable quality of at least up to 300 storage days. Results from this work highlight the influence of illumination condition on chia oil oxidative stability, suggesting that this oil should be stored in containers with light-barrier properties, and probably added to the antioxidants examined in the current study.
TL;DR: The rich microflora of Turkish keFir grains and their interactions with the aromatic properties of kefir were revealed and they were dominated by yeast species and Dipodascaceae family was dominant.
Abstract: Kefir grains consist of rich bacterial and fungal microflora responsible for the production of this traditional fermented milk beverage with unique flavour properties. Here, a pyrosequencing approach was applied for the identification of microbial flora of four kefir grains collected from different regions of Turkey and the volatile compounds in kefir samples produced with these grains were determined. Lactobacillus kefiranofaciens presented in all grains at important levels and Enterobacter, Acinetobacter, Enterococcus and Pseudomonas spp. were observed in traditional kefir grains. The fungal microflora of kefir grains was dominated by yeast species and Dipodascaceae family was dominant and Saccharomyces cerevisiae presented in all grains. Other yeast species belonging to Kazachstania, Candida, Issatchenkia and Rhodotorula species were also detected in kefir grains. Volatile compounds of kefir samples were also diverse related to the microbial diversity of kefir grains. This study revealed the rich microflora of Turkish kefir grains and their interactions with the aromatic properties of kefir.
TL;DR: In this article, the effects of substitution of wheat flour with faba bean flour and faba beans sourdough on the properties of composite bread were investigated, and the results showed that the addition of native Faba beans did not affect the in vitro protein digestibility.
Abstract: The effects of the substitution of wheat flour with faba bean flour and faba bean sourdough on the properties of composite bread were investigated. Bread was prepared by replacing wheat flour with 30% of faba bean flour, native or after sourdough fermentation. The addition of faba bean flour influenced the structure of the breads, causing a slight decrease of volume and higher hardness compared to wheat bread. However, when fermented faba bean flour was added, the crumb porosity of the bread was not affected. The addition of 30% of faba bean flour increased wheat bread protein content from 11.6 up to 16.5% of dry matter. The addition of native faba bean flour did not affect the in vitro protein digestibility, resulting similar to wheat bread (64%). On the contrary, faba bean sourdough bread showed higher protein digestibility (73%). Generally, the addition of native faba bean flour caused an improvement of the nutritional indexes of the composite bread, further enhanced when fermentation was carried out. The free amino acid profile, protein chemical score, and biological value index were the highest in faba bean sourdough bread. In addition, the predicted glycemic index was the lowest in faba bean sourdough bread.
TL;DR: The use of quinoa flour affected the textural characteristics of pasta, increased the tenacity and, when fermented, also the elasticity as discussed by the authors, showing the highest in Vitro protein digestibility, protein nutritional indices (Essential Amino Acid Index, Biological Value, Protein Efficiency Ratio, and Nutritional Index), as well as lowest predicted glycemic index.
Abstract: Pasta was prepared by replacing 20% of semolina with native and fermented quinoa flour and the effects of substitution on the technological and nutritional characteristics were evaluated. The addition of quinoa reflected the chemical composition of pasta, which had higher fiber, protein, and free amino acids content than semolina pasta, particularly in the case of pasta containing quinoa flour fermented with selected lactic acid bacteria. Furthermore, free amino acids, total phenols, and the antioxidant activity of pasta prepared with fermented quinoa flour were up to twice as high than the other types of pasta. When fermented quinoa flour was used, the water absorption during cooking was the lowest, even though cooking loss was also observed. The use of quinoa flour affected the textural characteristics of pasta, increased the tenacity and, when fermented, also the elasticity. The effects of quinoa fermentation were evident on the nutritional quality of fortified pasta, showing the highest in vitro protein digestibility, protein nutritional indices (Essential Amino Acid Index, Biological Value, Protein Efficiency Ratio, and Nutritional Index), as well as lowest predicted glycemic index. These results indicate the positive effect of fermented quinoa flour on pasta fortification.
TL;DR: In this article, the effect of acidic electrolyzed oxidizing water (AEW) on extending the shelf-life of blueberries during postharvest storage was evaluated, and the results suggested that AEW treatment can be used as a post-harvest technique to delay the softening process of blueberry during storage through lowering CWDEs activities and preventing degradation of cell wall components.
Abstract: This study was to evaluate the effect of acidic electrolyzed oxidizing water (AEW) on extending the shelf-life of blueberries during postharvest storage. On day 0, two cultivars of blueberries (Brightwell and Camellia) were washed by AEW with available chlorine concentration (ACC) of 48 mg/L at pH 2.8 for 5 min, and then stored at 4 °C until analyzing. Quality attributes of blueberries including firmness, cell wall composition and cell wall degrading enzymes were analyzed on days 0, 3, 6, 9, 12 and 15. Results showed that Brightwell softened faster than Camellia. AEW treatment slowed down the softening of both cultivars, while it had higher efficacy on delaying the softening of Camellia blueberries than the Brightwell blueberries. In addition, AEW treatment deactivated different cell wall degrading enzymes (CWDEs, polygalacturonase (PG), cellulase and β-galactosidase) and prevented the degradation of cell wall components including Na2CO3-soluble pectin (NSP), hemicellulose and cellulose. These results suggested that AEW treatment can be used as a postharvest technique to delay the softening process of blueberries during storage through lowering CWDEs activities and preventing degradation of cell wall components.
TL;DR: In this paper, the authors evaluated selected properties of precooked rice pasta enriched with different levels of legumes flours (yellow pea, chickpea, and lentil) using a modified single-screw extrusion-cooker, TS-45 (Polish design).
Abstract: The use of rice/leguminous blend may be nutritionally convenient in gluten-free product manufacturing. This study evaluated selected properties of precooked rice pasta enriched with different levels (10 g/100 g, 20 g/100 g and 30 g/100 g) of legumes flours (yellow pea, chickpea and lentil). Gluten-free spaghetti-type pasta was made using a modified single-screw extrusion-cooker, TS-45 (Polish design). Chemical composition, physical properties (expansion ratio, minimal preparation time, water absorption capacity, cooking loss, water absorption index, water solubility index, and color), texture properties (hardness, firmness and adhesiveness), and sensory attributes were evaluated. Microstructure of pasta products was examined with scanning electron microscope. Results showed that the addition of legumes flours decreased the expansion ration, the hardness, and the lightness, and increased the yellowness, the firmness and the adhesiveness, without affecting the minimal preparation time. Obtained results showed also that gluten-free pasta products had low cooking loss (
TL;DR: In this article, partial least squares regression (PLSR) models were developed based on the original spectra (381 wavelengths) and that pre-treated by multiplicative scatter correction or standard normal variate and nine wavelengths (414, 490, 520, 563, 580, 593, 634, 709, and 972) selected using regression coefficients from the PLSR models.
Abstract: The Vis-NIR hyperspectral imaging system (400–1000 nm) was used to determine moisture content in grass carp slices under diverse freeze drying periods. Partial least squares regression (PLSR) models were developed based on the original spectra (381 wavelengths) and that pre-treated by multiplicative scatter correction or standard normal variate and nine wavelengths (414, 490, 520, 563, 580, 593, 634, 709, and 972 nm) selected using regression coefficients from the PLSR models. The simplified PLSR model based on the selected wavelengths achieved good prediction results ( R c 2 = 0.9149, R c v 2 = 0.8974, R P 2 = 0.9021; RMSEC = 55.0 g/kg, RMSECV = 61.1 g/kg, RMSEP = 56.1 g/kg). In order to further improve the performance of the simplified model, weighted values (1.75, 1.33, 1.85, 2.65, 1.13, 2.80, 1.35, 1.00 and 1.00) obtained from the regression coefficients method were applied to the selected wavelengths, based on which, the optimised PLSR model was finally developed ( R c 2 = 0.9416, R c v 2 = 0.9278, R P 2 = 0.9117; RMSEC = 45.5 g/kg, RMSECV = 51.2 g/kg, RMSEP = 56.3 g/kg), indicating different importance of the selected wavelengths in model development. Finally, the optimised model was used to generate the distribution map of moisture content in the samples under various freeze drying periods.
TL;DR: In this article, the impact of high pressure processing (HPP; 600 MPa, 3min) on apple (Pink Lady, Granny Smith and Jonagold) juice quality changes compared to thermal processing (TP; P 8.3 ° C 85 ° C = 5 m i n ).
Abstract: This work evaluates the impact of high pressure processing (HPP; 600 MPa, 3 min) on apple (Pink Lady, Granny Smith and Jonagold) juice quality changes compared to thermal processing (TP; P 8.3 ° C 85 ° C = 5 m i n ). This comparative study was performed by integrating both an untargeted headspace-GC-MS fingerprinting and targeted approach to analyze the volatile fraction and a priori selected quality attributes (color, sugars, acids and enzymes) respectively. A significant higher total color difference (Δ E * >6.0) was determined for thermally treated juice. Polyphenol oxidase and peroxidase can be inactivated below detection limits by TP, while residual activity (>50%) was detected after HPP. Sugars and acids were almost not affected nor by HPP nor by TP. Using the untargeted fingerprinting approach, aldehydes, alcohols, ketones and organosulfur were detected in higher amounts after TP compared to untreated and HPP treated samples, which could be linked to the Maillard reaction and oxidative reactions. In general, the overall quality of HP treated apple juices is much more comparable to that of the fresh juice, in particular HPP results in lower amount of thermally induced compounds that are related to cooked notes of pasteurized apple juices.