Showing papers in "Lwt - Food Science and Technology in 2016"
TL;DR: In this article, active films from chitosan containing Eucalyptus globulus (EG) essential oil (0, 1, 2, 3 and 4% (v/v)) were developed by casting and solvent-evaporation method.
Abstract: In this work active films from chitosan containing Eucalyptus globulus (EG) essential oil (0, 1, 2, 3 and 4% (v/v)) were developed by casting and solvent-evaporation method. Then, the physical properties, the total phenolic content, the antioxidant and antimicrobial activities of different films were assessed, to define if the chitosan films incorporated with EG essential oil could be used as natural active films for food use. The antioxidant activity was determined with three different analytical assays (DPPH, NO and H2O2). The agar disc diffusion method was used to determine the antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Candida parapsilosis. In fact, incorporating EG essential oil into chitosan-based films significantly decreases moisture content and water-solubility. These results can be explained by the films microstructure, which was analyzed by scanning electron microscopy. The antioxidant properties proved to be significantly enhanced with increasing EG essential oil concentration. The microbiological assessment confirmed antimicrobial efficiency of chitosan films EG containing essential oil. The mentioned results proved the potential of this original material which could be used as active films due to its excellent antimicrobial and antioxidant activities.
296 citations
TL;DR: Fermented milk sample inoculated with L. plantarum KJ722784 exhibited decrease in viable count during storage at 4 °C on day 28, however, the survival count is greater than 7 log CFU/ml which is higher than the requirement of 6 log CFu/ml to exhibit health benefit.
Abstract: The present research was focused on probiotic characterization of lactic acid bacteria from fermented foods and beverage of Ladakh. Twenty five lactic acid bacteria were examined in vitro for potential probiotic properties based on their low pH tolerance, bile-salt resistance, lysozyme tolerance, cholesterol removal, hydrophobicity, autoaggragation, production of antimicrobial substances, exopolysaccharide production, β-galactosidase activity and haemolytic activity. The outcome of these studied parameters was used as input data for a principal component analysis (PCA) to select the most promising isolate and ten most potential probiotic isolates were identified through 16S rDNA sequencing. On the basis of PCA, isolate 84 (Lactobacillus plantarum KJ722784) showed similar trend to Lactobacillus casei Shirota used as reference strain in terms of probiotic properties. Fermented milk sample inoculated with L. plantarum KJ722784 exhibited decrease in viable count during storage at 4 °C on day 28. However, the survival count is greater than 7 log CFU/ml which is higher than the requirement of 6 log CFU/ml to exhibit health benefit.
244 citations
TL;DR: In this paper, phenolic grape skin extracts were prepared by using five choline chloride based natural deep eutectic solvents (NADESs) containing glucose, fructose, xylose, glycerol, malic acid and valorised by testing their biological activity in vitro using two human tumour cell lines (HeLa and MCF-7).
Abstract: In the present study phenolic grape skin extracts were prepared by using five choline chloride based natural deep eutectic solvents (NADESs) containing glucose, fructose, xylose, glycerol, malic acid and valorised by testing their biological activity in vitro using two human tumour cell lines (HeLa and MCF-7). Initially, used NADESs were investigated regard to their toxicity and low cytotoxicity of solvents was observed toward HeLa and MCF-7 cells (EC50 values > 2000 mg/L). Among used choline chloride based NADESs, the one containing malic acid showed the best performance concerning extraction efficiency (total phenolic and total anthocyanin were 91 and 24 mg/g dw), as well as antioxidant (ORAC values were 371 μmol TE/g dw) and antiproliferative activity (percentage of cell viability were about 20%). Herein, for the first time it was showed that NADES components could be chosen not only to fine-tune solvent physicochemical characteristics but also to enhance biological activity of extracts prepared in NADESs. Therefore, our research confirmed that NADESs are excellent and promising choice of solvents for sustainable and green extraction, which will lead to its novel application in food and pharmaceutical industry.
229 citations
TL;DR: This article explored the influence of adding pineapple peel powder (PPP) as a fibre source on physicochemical, textural, rheological, and microstructural attributes of probiotic yogurt during refrigerated storage for 28 days.
Abstract: Health benefits associated with dietary fibre consumption have shifted its applications towards inclusions into food products. This work aimed at exploring the influence of adding pineapple peel powder (PPP) as a fibre source on physicochemical, textural, rheological, and microstructural attributes of probiotic yogurt during refrigerated storage for 28 days. Skim milk with or without PPP or inulin as a control was fermented by yogurt cultures with or without addition of the probiotic cultures consisting of Lactobacillus acidophilus (ATCC® 4356™), Lactobacillus casei (ATCC® 393™) and Lactobacillus paracasei spp. paracasei (ATCC® BAA52™). PPP supplementation at 1% remarkably reduced fermentation time of milk co-fermented with probiotic organisms. Syneresis level in probiotic yogurt with PPP (1.16% at day 1) was comparable with the prebiotic-inulin and increased during storage. However, firmness and storage modulus in both plain and probiotic yogurts were lowered significantly with PPP addition. The reported information on physicochemical and structural attributes of probiotic yogurts with PPP could guide the dairy industry to utilize pineapple peel discarded as processing waste to close the fibre gap by developing a new synbiotic product with comparable attributes to inulin, a commercial prebiotic.
205 citations
TL;DR: Fish spoilage was significantly delayed in samples wrapped in chitosan-gelatin film containing different concentrations of GSE and/or ZEO, and GC-MS analysis of the essential oil components revealed that carvacrol and thymol were the most representative components of theessential oil.
Abstract: The aim of the present study was to evaluate the effects of chitosan-gelatin film incorporated with grape seed extract (GSE) (1 and 2%) and Ziziphora clinopodioides essential oil (ZEO) (1 and 2%), separately and in combination, on survival of Listeria monocytogenes and shelf life extension of minced trout fillet during refrigerated storage (4 ± 1 °C) over a period of 11 days The control and wrapped fillet samples were analyzed for chemical (PV and TVB-N), microbial (Total mesophilic and psychrotrophic bacteria, Pseudomonas spp, P fluorescens, Shewanella putrefaciens, lactic acid bacteria and Enterobacteriaceae family) and sensory properties (odor, color and acceptability) The GC-MS analysis of the essential oil components revealed that carvacrol (6522%) and thymol (1951%) were the most representative components of the essential oil In comparison with control group, fish spoilage was significantly delayed in samples wrapped in chitosan-gelatin film containing different concentrations of GSE and/or ZEO (P < 005) The lowest bacterial growth, PV and TVB-N content were obtained in fish samples wrapped in film containing ZEO2%+GSE2% The fillets treated with ZEO2%+GSE1% and ZEO2%+GSE2% had the best organoleptic properties Based on our findings, the antibacterial activity of chitosan-gelatin film incorporated with GSE and ZEO enhanced the shelf life of fish fillet
176 citations
TL;DR: In this article, the authors used ionic gelation to produce novel water-soluble and thermally stable chitosan nanoparticles (NPs) loaded with different levels of essential oil (Satureja hortensis L.) essential oil.
Abstract: The aim of this study was to produce novel water-soluble and thermally stable chitosan nanoparticles (NPs) loaded with different levels (1%, 1.2%, 1.4% and 1.5%) of summer savory (Satureja hortensis L.) essential oil (EO) using ionic gelation method and to determine their characteristic properties. NP samples with diameters ranging from 140.25 nm to 237.60 nm were obtained at pH levels of 4.5, 6.0 and 10.0. Zeta potential values of the NPs were found to be negative (−7.54 to −21.12 mV). Encapsulation efficiency (EE) was in the range of 35.07–40.70%. EO loaded NPs exhibited strong antibacterial (against Staphylococcus aureus, Listeria monocytogenes and Escherichia coli O157:H7) and DPPH scavenging activity dependently to the concentration of EO encapsulated. SEM images demonstrated the spherical shapes of the chitosan NPs. In conclusion, summer savory EO loaded chitosan NPs that were highly adapted to excessive environmental factors such as acidic pH and high temperature and with high bioactive properties were successfully fabricated convenient for future food processing and packaging applications.
170 citations
TL;DR: B. amyloliquefaciens showed significant improvement in nutritional quality and bioactivity by removing the protein- and carbohydrate-based anti-nutritional factors, as well as allergens, from solid-state fermentation process.
Abstract: To evaluate the impact of fermentation with Bacillus amyloliquefaciens U304 on nutritional quality and bioactivity of soybean meal (SBM), we analyzed the solid-state fermentation process for Bacillus amyloliquefaciens, Lactobacillus spp., and Saccharomyces cerevisiae. B. amyloliquefaciens showed significant improvement in nutritional quality and bioactivity by removing the protein- and carbohydrate-based anti-nutritional factors (ANFs), as well as allergens. The total phenolic content, reducing power, free radical scavenging ability, and Ca2+ chelating ability of SBM, as indicators of the antioxidant activity, increased to 195.8, 201.7% (at 10 mg/mL), 136.6% (at 10 mg/mL), and 122.3%, respectively, after Bacillus fermentation. S. cerevisiae decomposed carbohydrate-based but not protein-based ANFs, and fermentation with this organism produced similar values of the antioxidant markers of unfermented soybean meal, except for the reducing power (160.0% at 10 mg/mL). Lactobacillus spp. was only effective for decreasing the activity of trypsin inhibitors, but not other ANFs, resulting in lower bioactivity of fermented soybean meal. B. amyloliquefaciens U304 can substantially improve both the nutritional quality and bioactivity of SBM.
159 citations
TL;DR: In this article, carboxymethyl cellulose (CMC) was incorporated into 2-N-Hydroxypropyl-3-trimethylammonium chloride chitosan (HTCC) blend films to develop coating for preserving food.
Abstract: Antibacterial property of packaging is needed to improve the microbiological safety of foods. The aim of this work was to incorporate various amounts of carboxymethyl cellulose (CMC) into films based on quaternized chitosan (2-N-Hydroxypropyl-3-trimethylammonium chloride chitosan, HTCC) to develop coating for preserving food. The HTCC film and blend films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction measurements, scanning electron microscopy, and thermogravimetric analysis. The effects of CMC content on the physical properties and antibacterial activities of the blend films were investigated. The effect of coating bananas with the films on their preservation was also determined. The results revealed that HTCC and CMC in the blend films interacted by hydrogen bonding. Both of them could be partly miscible. Compared with HTCC100 film, CMC incorporation improved tensile strength, thermostability, and water resistance, however, increased oxygen permeability, and decreased light transmittance and antibacterial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Bananas coated with the HTCC/CMC blend films had longer shelf life than uncoated bananas. CMC incorporation thus evidently reinforced the HTCC film and lowered its WVP. These results suggest that HTCC/CMC blend films can be used as food packaging materials.
159 citations
TL;DR: Chinese cinnamon showed the best antibacterial activity among all EOs and it inhibited S. aureus and E. coli at low minimum inhibitory concentration (MIC) of 470 ppm, and combined Chinese cinnamon and Cinnamon bark EOs showed additive antibacterial effects against all bacteria.
Abstract: The antibacterial activity of 32 Essential Oils (EOs) was assessed against four pathogenic bacteria (Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, and Salmonella Typhimurium) and one spoilage bacterium (Pseudomonas aeruginosa). Agar diffusion, micro-atmosphere and microbroth assays were used to evaluate the antibacterial activity in solid, vapour and liquid phase, respectively. In solid phase, Red thyme, Red bergamot, Ajowan, Summer savory, Chinese cinnamon, and Cinnamon bark had higher inhibitory zone (20-40 mm) against five target bacteria as compared with other EOs. Red thyme, Red bergamot, Ajowan, Summer savory inhibited S. aureus by more than 60 mm. In vapour phase, at 30 μl of tested EOs, Chinese cinnamon and Red bergamot were the only EOs that inhibited all target bacteria with the inhibition zone from 20 to more than 60 mm depending on target bacteria. In liquid phase, Chinese cinnamon showed the best antibacterial activity among all EOs and it inhibited S. aureus and E. coli at low minimum inhibitory concentration (MIC) of 470 ppm. In checkerboard method, combined Chinese cinnamon and Cinnamon bark EOs showed additive antibacterial effects against all bacteria. Sensory evaluation of combined Chinese cinnamon and Cinnamon bark EOs used in cooked meat was conducted and an EO level of 0.05% was the highest organoleptically acceptable. © 2015 Elsevier Ltd.
150 citations
TL;DR: In this paper, scales and skin of tilapia were extracted for acid-soluble collagen (ASC) analysis and the results indicated that ASC may be suitable for use as an alternative to land-based mammalian collagen in food, nutraceuticals and pharmaceutical industries.
Abstract: Acid-soluble collagen (ASC) was extracted from scales and skin of tilapia. The yields of scale collagen (SCC) and skin collagen (SKC) were 3.2 g/100 g and 27.2 g/100 g respectively, dry weight. The SDS-PAGE profile showed all collagen samples contained [α1(I)]2α2(I) component and were characterized as type I collagen. LC-MS/MS analysis confirmed the SCC and SKC to be Oreochromis niloticus type I collagen. Amino acid analysis revealed the imino acid content from the SCC and SKC samples were 207 and 197 residues/1000 amino acid residues, respectively. Based on FTIR spectra and X-ray diffraction, isolation of ASC did not affect its three dimensional structure. Zeta potential studies indicated both SCC and SKC exhibited a net zero charge at pH 6.82 and 6.42, respectively. Both ASC samples exhibited high solubility in acidic pH (1–3) and lost their solubility at NaCl concentrations below 3 g/100 mL. The data collected here indicate that SCC and SKC may be suitable for use as an alternative to land-based mammalian collagen in food, nutraceuticals and pharmaceutical industries.
144 citations
TL;DR: In this paper, the effect of power intensity of ultrasound and temperature on the pectin extraction from passion fruit peel was evaluated by response surface methodology, and the results showed that the use of ultrasound promoted a better extraction yield of pectins when compared to the conventional method.
Abstract: The effect of power intensity of ultrasound and temperature on the pectin extraction from passion fruit peel was evaluated by response surface methodology. The extraction was performed using a dried peel/extractant ratio fixed at 1:30 for 10 min of sonication. The dependent variables were the yield, the galacturonic acid content and the esterification degree of the extracted pectin. The highest yield of pectin was obtained by power intensity of 644 W/cm2 and temperature of 85 °C. Under these conditions, the yield, the galacturonic acid content and the esterification degree were 12.67%, 66.65% and 60.36%, respectively. The conventional extraction (dried peel/extractant ratio 1:30, 10 min and 85 °C) was performed to compare the results to the ultrasound-assisted extraction. The results showed that the use of ultrasound promoted a better extraction yield of pectin when compared to the conventional method.
TL;DR: In this article, the authors used a solvent-casting method to modify the properties of PLA film and their properties were evaluated using FT-IR and DSC test results indicated that PLA is highly compatible with PBAT to form homogeneous blend films, and the flexibility of PLA films increased significantly by blending small amount of PBAT without significant decrease in mechanical properties.
Abstract: Blend films with poly(lactide) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) were prepared using a solvent-casting method to modify the property of PLA film, and their properties were evaluated. FT-IR and DSC test results indicated that PLA is highly compatible with PBAT to form homogeneous blend films. The flexibility of PLA films increased significantly by blending small amount of PBAT without significant decrease in mechanical properties. Even the blend film with small amount of PBAT, 3.92 g of PLA with 0.08 g of PBAT (PLA 98 /PBAT 2 ), exhibited UV screening effect without sacrificing transparency. The water vapor permeability and oxygen transfer rate of the blend films were varied depending on their blending ratio. In the packaging application for potatoes and green onion, the blend films exhibited preventing of greening of packaged potatoes and also showed antifogging effect with reduced quality changes in the packaging of green onion. The blend films have high potential for being used as UV screening or antifogging packaging films.
TL;DR: In this paper, the effects of encapsulation with alginate and chitosan, with or without inulin, on viability of probiotic Lactobacillus rhamnosus GG in apple juice during 90 days storage at 4 and 25°C were evaluated.
Abstract: In the present study the effects of encapsulation with alginate and chitosan, with or without inulin, on viability of probiotic Lactobacillus rhamnosus GG in apple juice during 90 days storage at 4 and 25 °C were evaluated. Moreover, the probiotic survival under simulated gastrointestinal conditions and sensory attributes during apple juice storage were investigated. The survival rate of free bacteria decreased to 13.6% through the storage. The encapsulated L. rhamnosus experienced greater survival rate which was 4.5 times higher than that of free bacteria at day 90. Encapsulation of L. rhamnosus improved bacterial viability since 27.7% of bacterial population survived gastrointestinal transition model. Furthermore, inulin addition had a significant positive effect (p
TL;DR: In this paper, the nano-titanium dioxide nanoparticles were incorporated in the fish gelatin layer of bilayers to improve the barrier properties of bilayer films against UV light at low concentration, while increasing their opacity.
Abstract: Bilayer gelatin/agar films containing different concentrations of TiO2 (0.5, 1, and 2 g/100 g) were prepared by incorporation of anatase titanium dioxide nanoparticles in the fish gelatin layer of the bilayers. Gelatin/agar bilayer film was produced from the monolayers using the casting method in two steps and their microstructural, physical, mechanical and optical characteristics were studied. Results showed that the addition of TiO2 decreased water vapor permeability of the bilayers more than 30%, upon increasing TiO2 content to 2 (g/100 g). However, swelling ratio and moisture content increased with the increase in the nano-TiO2 content, probably due to the hydrophilic nature of the TiO2 nanoparticles. The tensile strength of the bilayer films increased from 10.80 to 13.91 MPa upon increasing nano-TiO2 content from 0 to 0.5 (g/100 g); however, tensile strength decreased with further increase of the nanoparticle concentration. In addition, the metallic nature of nano-TiO2 considerably improved the barrier properties of the bilayer films against UV light at low concentration, while it increased their opacity. This property might help in the preservation of light-sensitive foods, but more studies on real food systems are required.
TL;DR: In this article, the physicochemical properties of monofloral honeys produced by the stingless bee M.subnida Duke and Melipona scutellaris Latrelle in a Brazilian semi-arid region were analyzed regarding their physicochemical (moisture, protein, proline, hydroxymethyl-furfural, color, electrical conductivity, pH, free acidity, and sugar profile).
Abstract: Monofloral honeys produced by the stingless bee M. Subnida Duke and Melipona scutellaris Latrelle in a Brazilian semi-arid region were analyzed regarding their physicochemical (moisture, protein, proline, hydroxymethyl-furfural, color, electrical conductivity, pH, free acidity, and sugar profile) and sensory aspects (color, viscosity and flavor). The floral source influenced the color, acidity, sugar profile, ash and proline content in the honeys. The intensity of the acidic flavor, sweet taste and color in the honeys varied according to the floral source. No differences were perceived for honeys from the same floral source produced by different bee species. Principal component analysis revealed that most of the variability was defined by the water content, total acidity, glucose, sucrose and color, as well as by acid taste, acid flavor, honey flavor and sweet taste. These findings reveal that Brazilian monofloral honeys produced by stingless bees possess well-defined characteristics that are influenced by the floral source.
TL;DR: In this paper, the effect of HPMC edible coating with OEO and BEO for fresh ‘Formosa’ plum was analyzed using physiochemical properties and sensory parameters, which indicated that the 2% H-OEO coating treatment showed good potential to extend the storage quality of harvested plums.
Abstract: Hydroxypropyl methylcellulose (H) films incorporated with oregano and bergamot essential oils were characterized and evaluated for their effectiveness suitability as an edible coating for fresh ‘Formosa’ plum. The effects of the oregano essential oil (OEO) and bergamot essential oil (BEO) at different concentrations of 0.5, 1, 1.5, and 2% (w/w) in the HPMC edible films were observed by measuring their physical and mechanical properties, gas permeation, color values, transparency, antimicrobial activities. The effect of HPMC edible coating with OEO and BEO for fresh ‘Formosa’ plum were analyzed using physiochemical properties and sensory parameters. The 2% H-OEO coating was shown to be very effective in reducing the respiration rate, ethylene production, total weight loss, and total cell count, compared to the plums treated with other coatings at 23 ± 2 °C. In addition, the 2% H-OEO coated plum was firmer and showed less surface color change than the control fruit at the end of storage. The results of our study indicated that the 2% H-OEO coating treatment showed good potential to extend the storage quality of harvested plums. Among all of the sample sensory aspects of H-OEO, H-BEO and H, increased respectively.
TL;DR: In this paper, the effect of different drying methods (by freeze-drying (FD), vacuum (VD), convective drying (CD), microwave (VMD), and combined method (CVM)) on the quality factors of chokeberry fruit, including phenolic compounds, antioxidant activity, and color were determined.
Abstract: Drying has been long known and widely used method of food preservation. The aim of this study was to determine the effect of different drying methods (by freeze-drying (FD), vacuum (VD), convective drying (CD), microwave (VMD) and combined method (CVM)) on the quality factors of chokeberry fruit, including phenolic compounds, antioxidant activity, and color. All products were characterized by water activity which determines their storage stability. The highest content of bioactive compounds and antioxidant activity were determined in freeze-dried samples, compared with fresh fruits (total phenolic in gallic acid equivalents- 8008 mg/100 g dm, anthocyanins- 3917 mg/100 g dm). The increase in air temperature during CD as well as the increase in material temperature during VMD deteriorated dried product quality in terms of the content of phenolic compounds, antioxidant activity, and color, which was correlated with anthocyanin content. A new combined CVM method allowed obtaining high quality dried material compared to the CD and VMD methods applied separately. The drying process affected changes in the appearance and brightening of color, and also increased the contribution of yellow color in the fruits. The results show that the quality of dried chokeberry depends on the method and conditions of fruit drying.
TL;DR: In this paper, the impact of microcrystalline cellulose (MCC) on the physical stability, microrheological property and freeze-thaw stability of papain hydrolysate of soybean isolate protein (SPIH) stabilized curcumin emulsion was studied.
Abstract: The impact of microcrystalline cellulose (MCC) on the physical stability, microrheological property and freeze-thaw stability of papain hydrolysate of soybean isolate protein (SPIH) stabilized curcumin emulsion was studied. Curcumin emulsions were prepared by Microfluidizer containing SPIH and various concentrations of MCC. The curcumin emulsions were assessed by zeta potential, average particle size through dynamic light scattering technique (DLS), stability index by Turbiscan and microrheological behavior through diffusive wave spectroscopy (DWS) technique. With addition of MCC, the negative charge of the droplets was increased, which indicated that the negatively charged fraction from MCC interacted with the protein at the interface. An increase in droplet size and decrease in TSI were noted with increasing MCC concentration. It demonstrated that enough MCC changed microrheological property of curcumin emulsions from purely viscous to viscoelastic over the range of decorrelation times, indicating that the droplets were not free to move due to the droplets network interaction. Freeze-thaw stability analysis demonstrated that MCC brought about a remarkable improvement, which can be attributed to the enhancement of repulsive steric forces between the curcumin droplets. It demonstrated that combined enzymatic hydrolysate of protein and addition of polysaccharide MCC could be an effective method for protecting bioactive compound in emulsions.
TL;DR: In this article, the impact of cooking and germination on dietary fiber and phenolic compound composition was studied in beans (Phaseolus vulgaris L.) and lentils (Lens culinaris L.).
Abstract: The impact of cooking and germination on dietary fibre and phenolic compound composition was studied in beans (Phaseolus vulgaris L.) and lentils (Lens culinaris L.). An investigation on phenolic compounds in dietary fibre fractions was carried out due to the scarce literature on the behaviour of these compounds during legume processing. A general decrease in the concentration of insoluble and soluble fibre fractions were observed in processed bean and lentil flours, although an increase in the content of insoluble and soluble fibre fractions in sprouts and cooked beans, respectively, was found. Hydroxybenzoic and hydroxycinnamic compounds, flavan-3-ols, procyanidins, flavonols and flavones were identified in dietary fibre fractions in cooked and germinated beans and lentils. Phenolic compound constituents of the different dietary fibre fractions accounted from 73% to 97% in insoluble dietary fibre fraction (IDF) flours and from 3% to 25% in soluble dietary fibre fraction (SDF) in raw and processed bean and lentil flours. These processing techniques may produce positive changes in the dietary fibre and phenolic compound composition and its association could improve phytochemical and nutritional quality and maximize the health-promoting properties of legumes.
TL;DR: In this paper, chitosan solutions were applied as fruit coating for ‘Nam Dok Mai’ mango ( Mangifera indica L.) and stored at 25°C for 16 days.
Abstract: ’Nam Dok Mai’ mango is an important export fruit of Thailand. However, the quality of fruit is reduced after harvest. Therefore, it is necessary to develop a postharvest treatment to maintain the quality of ’Nam Dok Mai’ mango after harvest. Chitosan solutions (high molecular weight (HM-CTS), medium molecular weight (MM-CTS), and low molecular weight (LM-CTS)) were applied as fruit coating for ‘Nam Dok Mai’ mango ( Mangifera indica L.) and stored at 25 °C for 16 days. The film forming properties of chitosan were influenced by molecular weight and significantly impacted postharvest quality of mango fruit during storage. HM-CTS could delay mango fruit ripening and thus maintaining the highest value of titratable acidity, fruit firmness, and also resulting in a reduction of weight loss, ethylene production, and respiration rate of mango fruit. Moreover, HM-CTS coated fruit exhibited no incidences of disease throughout storage. DPPH inhibition and ascorbic acid content were maintained in coated fruit during storage. H 2 O 2 content was inhibited by catalase and ascorbate peroxidase activities in HM-CTS coated fruit. These data indicated that the application of HM-CTS could be used to reduce deteriorative processes, maintain quality, and increase the shelf life of ‘Nam Dok Mai’ mango during postharvest storage.
TL;DR: Jambolan fruit polyphenol extract exhibited a broad spectrum antimicrobial activity against reference pathogenic strains with a zone of inhibition and minimum inhibitory concentration in the range from 14.3 to 23.0 mm and 0.5–2.5 mg/ml, respectively.
Abstract: The present study was undertaken to examine antioxidant and antimicrobial activities of jambolan fruit polyphenols against reference pathogenic strains (Staphylococcus aureus, methicillin-resistant S. aureus [MRSA], Escherichia coli, Klebsiella pneumoniae and Candida albicans) and were compared to that of polyphenol standards (gallic acid, quercetin, caffeic acid, sinapic acid and delphinidin chloride). DPPH, ABTS and FRAP assays showed that antioxidant activity for different polyphenols varied significantly (P
TL;DR: Results of this study confirmed the biodiversity of LAB species in traditional Turkish Sourdough and highlighted the importance of EPS production in sourdough LAB strains.
Abstract: A total of 249 Lactic Acid Bacteria (LAB) isolates were found in traditional Turkish wheat sourdoughs from Eastern Black Sea region of Turkey. Genotypic characterization of these isolates revealed the presence of 47 distinct LAB strains belonging to 11 different species: Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus curvatus, Lactobacillus rossiae, Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, Weissella paramesenteroides, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides and Weissella cibaria. The sourdough LAB microbiota differed depending on the sample origin and the collection period and heterofermentative LAB were dominant. The number of different species within a sourdough varied from 3 to 6 with the association of different hetero- and homofermentative LAB species. Exopolysaccharide (EPS) production characteristics of the isolates were determined and strain specific properties appeared to be important for the final EPS yields. Genes required for homopolysaccharide (gtf and lev) and heteropolysaccharide (epsA, epsB, p-gtf) production were PCR detected and several distribution patterns were observed. Results of this study confirmed the biodiversity of LAB species in traditional Turkish sourdough and highlighted the importance of EPS production in sourdough LAB strains.
TL;DR: In this article, the physicochemical and sensory properties of extruded product by using response surface methodology (RSM), effect of different moisture content in raw material and the temperature of extrusion processing on the inactivation of these antinutritional factors in lentil.
Abstract: Lentil contains substantial amount of protein, carbohydrate, fiber and other nutrients like folate and iron but their bioavailability and utilization by human is relatively low and less explored, this is due to the presence of various antinutritional factors such as trypsin inhibitor, phytic acid and tannins. The present study was aimed to evaluate the physicochemical and sensory properties of extruded product by using response surface methodology (RSM), effect of different moisture content in raw material and the temperature of extrusion processing on the inactivation of these antinutritional factors in lentil. The attempts were also made to assess in vitro protein and starch digestibility. The die temperature has been varied from 140 to 180 °C with screw speed of 150–250 rpm at constant feed rate 16 rpm (340 g/min) and the feed moisture of the raw material was in the range of 14–22%. It was observed that extrsion was the best method to abolish trypsin inhibitors (99.54%), phytic acid (99.30%) and tannin (98.83%) without altering the protein content. Furthermore, it was also found that the associated thermal treatment was most effective in improving protein and starch digestibility (up to 89% and 96%, respectively) when it was compared with traditional thermal processes.
TL;DR: In this paper, the effects of carboxymethyl cellulose (CMC) coatings in combination with CaCl 2 and ascorbic acid (AA) has been studied.
Abstract: Fresh cut apples have a short shelf-life due to their high rate of deterioration, water loss and cut-surface browning that can rapidly reduce fruit quality. In this study the effects of carboxymethyl cellulose (CMC) coatings in combination with CaCl 2 and ascorbic acid (AA) has been studied. Apple slices were dipped for 5 min in distilled water (uncoated), CMC (1% w/v) + CaCl 2 (0.5%), or CMC (1%) + CaCl 2 (0.5%) + AA (2%), and then stored at 4 °C, 90–95% (RH). The treatments suppressed browning, retained flesh firmness, and reduced soluble solid content, titratable acidity and pH changes of the slices. Browning incidence with CMC in combination with AA was lower than that of CMC solely. Vitamin C and antioxidant capacity in treatments was higher than that of uncoated. Coating treatments generally reduced total phenolic and flavonoid concentrations and polyphenol oxidase and peroxidase activity changes of slices during storage. These findings suggest that the combination use of CMC + AA may be useful for maintaining quality and reducing surface browning of fresh cut apples.
TL;DR: In this paper, the use of LF-NMR technique for assessing the influence of protein hydration states on the mobility water and fat in the proton mobility was investigated, and three relaxation components, T22 (50ms), T2b and T21 (lower than 10ms) were found in both the fat and water groups.
Abstract: The use of LF-NMR technique for assessing the influence of meat protein hydration states on the mobility water and fat in meat batters was investigated. Three relaxation components, T22 (50 ms), T2b and T21 (lower than 10 ms) were found in meat group and fat group. The number of relaxation components in meat batters was not affected by water or fat addition, but the major component T22 clearly shifted to longer relaxation time (from 50 ms to 66 ms) with added water and fat. The relaxation time of heated meat emulsions was lowered, indicating that water and fat proton mobility was limited by heating. A new relaxation component T23 (200–300 ms) was observed after heating, which was deemed as attributing to free water and fat in emulsion gel. Besides, the effect of fat on relaxation time T22 of emulsion gel was higher than water. However, water presented higher influence on T23 in emulsion gel compared to fat. LF-NMR has been clearly demonstrated to be feasible to detect changes in the relaxation times of water and fat caused by different meat protein hydration states initially produced by meat batters with different treatments.
TL;DR: In this article, the antimicrobial and antioxidant properties of Zein films assimilated with 1% monolaurin (ML) and 2 or 3% Zataria multiflora Boiss essential oil (ZEO) were determined and their antimicrobial effects against Listeria monocytogenes and E.coli O157: H7 in vitro and in minced beef meat were determined.
Abstract: Zein films assimilated with 1% monolaurin (ML) and 2 or 3% Zataria multiflora Boiss. essential oil (ZEO) were developed and their antimicrobial effects against Listeria monocytogenes and E. coli O157: H7 in vitro and in minced beef meat were determined. Zein films were developed using casting method. Films containing 1% ML + 3% ZEO had the highest swelling index (52.3%). Only ZEO containing films had a remarkable phenolic (13.53 mg gallic acid/g film) and plain zein films had no phenolic contents. Similar improvement were obtained for antioxidant activity of films containing ZEO. Antimicrobial activity was significantly increased by adding ZEO and ML which influenced by the concentrations of agents as well as type of bacteria, which L. monocytogenes was more susceptible than E. coli . In minced meat, the growth of L. monocytogenes was significantly inhibited by ML and/or ZEO containing films during 3 days of storage at 4 °C, whereas the growth of E. coli was only inhibited by films containing ZEO. The results showed the antimicrobial and antioxidant activity of zein film by addition of ZEO and ML. In the case of combination, ZEO and ML had no additive or synergistic antimicrobial effects.
TL;DR: The result of the study indicated that LAB strains had a great ability to produce succinic acid, which varied significantly depending on bacterial strains and growth medium.
Abstract: Organic acids (lactic, acetic, succinic, propionic, formic and butyric acid) production by lactic acid bacteria (LAB) were investigated in various fish infusion broth (anchovy, sea bass, tilapia and trout) and MRS broth (control) by using HPLC method. Significant differences were found in organic acid levels (P < 0.05) among bacterial strains. Succinic acid formation was the highest by LAB whilst acetic acid was produced at the lowest levels. The highest lactic acid production was observed with Lactobacillus lactis subsp. lactis and Pediococcus acidilactici in anchovy infusion broth, with values of 2403 and 2345 mg/L, respectively. Acetic acid production was 822 and 803 mg/L by Lactobacto acidophilus and Lactobacillus delbrueckii subsp. lactis in anchovy infusion broth, respectively while succinic acid production ranged from 142 mg/L by Lb. delbrueckii subsp. lactis in sea bass infusion broth to 9231 mg/L by Lb. lactis subsp. lactis in MRS broth. Propionic acid formation by Pc. acidilactici was 3747 mg/L in sea bass infusion broth whereas Lb. lactis subsp. cremoris produced less than that in MRS broth. The result of the study indicated that LAB strains had a great ability to produce succinic acid. Also other organic acid production varied significantly depending on bacterial strains and growth medium.
TL;DR: In this article, the authors investigated the changes in total phenolic content (TPC), total flavonoid content, individual phenolic compound content, DPPH radical scavenging activity and antioxidant capacity measured by FRAP assay of four phenolic fractions (free, esterified, glycosided and insoluble-bound) from jujube during three edible maturity stages.
Abstract: This study investigated the changes in total phenolic content (TPC), total flavonoid content (TFC), individual phenolic compound content, DPPH radical scavenging activity and antioxidant capacity measured by FRAP assay of four phenolic fractions (free, esterified, glycosided and insoluble-bound) from jujube during three edible maturity stages. The maturity stages of jujubes were established as white maturity (WM), half-red maturity (HM) and red maturity (RM). The free fraction in jujube at WM stage had the highest TPC, TFC, total phenolic acid contents, and antioxidant capacities. The phenolic contents and their activities greatly decreased with the increasing maturity stage. Caffeic acid was the most predominant in all detected phenolic compounds at WM stage, while rutin dominated at HM and RM stages. Even though most of phenolic compounds with antioxidant activity in jujube existed at the WM stage as the free form, the insoluble-bound fractions also contained a large number of phenolic compounds.
TL;DR: In this article, the physicochemical and sensory properties of heat-treated, gluten-free bread and cake were studied and compared with control bread and cakes, and the overall acceptability score for bread was 5.05 and 4.76 with heat treated and control flour respectively.
Abstract: The effects of heat treatment on sorghum flour functionality in gluten-free bread and cake were investigated. The sorghum flour was subjected to dry-heat at two temperatures (95 °C and 125°) for 15, 30, and 45 min. The physicochemical and sensory properties of heat-treated, gluten-free bread and cake were studied and compared with control bread and cake. Flour heat treatment affects viscosity which has an important role in final cake and bread quality. Heating the flour at 125 °C for 30 min produced bread with the highest specific volume (3.08 mL/g) and the most cells per slice area (50.38 cells/cm 2 ). This treatment also produced cakes with the highest volume (72.17 cc) and most cells per slice area (79.18 cells/cm 2 ). The control sorghum flour produced breads and cakes with low volume, poor crumb properties, and dense textures. Additionally, cake and bread made from this heat treatment were more acceptable than the controls in consumer testing. The overall acceptability score for cake made with heat treated sorghum flour was 6.65 compared to 5.98 for control. The overall acceptability score for bread was 5.05 and 4.76 with heat treated and control flour respectively. These results can assist in advancing the quality of sorghum-based gluten-free foods for the celiac consumers.
TL;DR: In this paper, high-hydrostatic pressure (HHP) treatments of 650 MPa at different processing times (3, 7, 15 and 30 min) were applied on beetroot slices (var. red cloud ) as an alternative to blanching pretreatment (90°C for 7min).
Abstract: In this work, high-hydrostatic pressure (HHP) treatments of 650 MPa at different processing times (3, 7, 15 and 30 min) were applied on beetroot slices (var. Red cloud ) as an alternative to blanching pretreatment (90 °C for 7 min). Polyphenol oxidase (PPO) and peroxidase (POD) activity, physical (texture and color) and nutritional (betanins retention, total phenolic content, antioxidant capacity and ascorbic acid) parameters were evaluated. Differently from blanching, HHP led only to partial inactivation of PPO (10–25%) and POD (25%) at each tested time. Total phenol content and FRAP value were found to be statistically similar ( p > 0.05) in HHP-treated and blanched beetroot. An increase of betanins content was observed in HHP-treated samples, resulting in 6-fold higher content in comparison to the raw. However, the higher the time-exposure to high pressure, the higher pigments degradation, as similarly observed for ascorbic acid. Finally, texture properties such as hardness and chewiness were better retained in HHP samples than in thermally treated ones, showing an increase according to the time of pressure exposure. Overall, the HHP processes improved the nutritional quality of the products, as revealed from the principal component analysis.