The main benefits of edible active coatings are to maintain the quality and extend shelf-life of fresh fruits and prevent microbial spoilage. Chitosan have a wide range of potential application in different fields of chemical sciences, biological systems, food sciences, pharmaceutical and medical industries. Chitosan has been proven one of the best edible and biologically safe preservative coatings for different types of foods because of its film-forming properties, antimicrobial actions, lack of toxicity, biodegradability and biochemical properties. It has been proven that the chitosan can control numerous pre and postharvest disease of fresh fruits. Chitosan edible coatings extend the shelf life of the fruits and vegetables by minimizing the rate of respiration and reducing the water loss. Chitosan coating offers a defensive barrier against bacterial contamination and loss of moisture from the surface of food products, thus extending their shelf life. With limited increase in the concentration of chitosan coating, the beneficial effect of chitosan on postharvest life and quality of the food is enhanced. The present review delineates the preparation, properties and potential application of chitosan coatings for enhancing the postharvest life and quality of different types of fruits.
An ultrasonic-assisted extraction method was employed to get high quality bioactive polysaccharides from Sargassum fusiforme (SFP), with the technology optimized in light of an orthogonal test design L9 (33). Being the major factors that influence the yield of the extracts, the ultrasonic power, water/solid ratio, and extraction time were selected on the basis of a single-factor test. The extraction yield and the antioxidant activity of SFP were used as dependent variables in the analysis of the orthogonal test results. The antioxidant activity of SFP was evaluated using IC50 of scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the activity monitoring parameter. The optimum extraction conditions were obtained when the ultrasonic power, the extraction time, and the ratio of water to solid were 800 W, 10 min and 20, respectively. Under the optimized conditions, the SFP extracted with the optimized ultrasonic-assisted method exhibited strongest DPPH radical scavenging activity (P < 0.05) compared with conventional hot water extracted SFP and other two antioxidants.
Biochemical and mineral composition and some functional properties of seed kernel of Lotus (Nelumbo nucifera) cultivated in Southern Punjab, Pakistan, were determined. The seed kernel was found to be good source of crude protein (15.3 ± 0.09 g/100g dry weight) and total carbohydrate (69.72 ± 0.29 g/100g dry weight) and possesses high calorific value (364.10 ± 1.74 Kcal/100g dry weight). The seed kernel was also found to be good source of essential minerals such as Na, K, Mg, Fe, Co, Zn and P. Response-surface methodology was used to study the effect of temperature and heating time on some functional properties of flour of seed kernel. Significant linear positive effect (p < 0.05) of temperature on swelling capacity and that of heating time on water absorption capacity and solubility was observed. Both variables have significant quadratic effect (p < 0.05) on water absorption and foaming capacities. The data provides valuable guidelines regarding the use of lotus seed kernel in food formulations.
Kavurma is a cooked meat product which is produced in Turkey, the Middle East and some Asia countries. In this study, the effect of ethanol extracts from nettle, rosemary and myrtle leaves on lipid oxidation and microbial growth of vacuum-packaged kavurma was investigated. Kavurma was made from beef meat and beef meat fat in 4 groups: No-added extract, 0.4% nettle extract, 0.4% rosemary extract and 0.4% myrtle extract. The kavurma produced was stored at 4°C for 180 days. The ethanol extracts from nettle, rosemary and myrtle slowed down the lipid oxidation and inhibited the bacterial growth of kavurma. The best results were found in the treatment with myrtle extract for lipid oxidation, and in the treatment with nettle extract for microbial growth. Treatment had no significant effect on fatty acid profiles. These results suggest that the use of myrtle and nettle extracts could control lipid oxidation and microbial growth in kavurma, respectively.
Roasting is one of the important unit operation steps in cocoa base food industries. Cocoa beans (Theobroma cacao) were roasted using superheated steam oven (Healsio, AV-1500V, SHARP) in superheated steam mode and convection mode operated at three set of temperatures (150°C, 200°C and 250°C) for 5 to 35 min. The changes occurred in the physical properties; colors, texture (hardness and fracturability), moisture content and heat inside the beans were examined at the same temperature and time. During superheated steam roasting the color values were more affected than convection roasting. Hardness of the cocoa beans were more affected by the convection roasting mode as compared to superheated steam while fracturability values were more affected in superheated steam mode as compared to convection roasting. The moisture losses of the cocoa beans were lower at each temperature in superheated steam roasting as compared to convection roasting whereas the heating rate inside cocoa beans was higher in superheated steam.
The suppression of trimethylamine-N-oxide decomposition to dimethylamine (DMA) and formaldehyde is required to ensure the stability of frozen minced meat from gadoid species. The effects of a mixing treatment on the stability of frozen minced meat were investigated. Minced meat samples from pollock, southern blue whiting (SBW), and hoki were mixed for 1 − 10 min with 8.3% sucrose using a silent cutter and stored at −23°C for 6 months. The salt solubility of minced pollock and SBW, but not hoki meat, was stabilized by the 10-min mixing treatment, and DMA formation was reduced with increased mixing time, which may have been due to oxidation of the minced meat by the O2 in the air. Minced SBW meat mixed for 10 min had similar properties to surimi even though water- and oil-holding capacities were slightly different.
In this study, whole wheat bread (WWB) prepared by whole wheat flour (WWF) which its branny fraction (35 ± 1% w/w whole flour) previously was stabilized with different processes. These fractions were stabilized using autoclave (AU), microwave (MW), infrared (IR) and ultraviolet-C (UV-C) methods. Then, WWF obtained by remixing of stabilized branny fraction (35 ± 1% w/w) and wheat flour (65 ± 1% w/w) of same wheat samples. The WWF samples were used in breadmaking. As parameters, the external (loaf weight, volume, specific volume, crust color) and the internal (crumb color and hardness) properties of the WWB were measured. The increase in strongness of wheat gives WWB with desirable quality characteristics, besides the stabilization processes enables to produce bread having higher loaf volume, crust redness, crumb lightness and crumb softness. As a result of this study, all stabilization processes had an improving effect on external and internal properties of WWB. The best results were obtained by AU and MW stabilization methods.
The network structure of high acyl gellan polysaccharide was investigated using dynamic viscoelasticity and steady flow viscosity measurements, as well as atomic force microscopy (AFM). Time-temperature superposition (TTS) of mechanical spectra of aqueous dispersions having a gellan concentration of 0.1% w/w revealed a gel-like response at the lower end of the frequency range. The TTS master curve of the steady flow data exhibited a power-law relationship between shear viscosity and shear rate at the lower end of the shear rate range, instead of a Newtonian plateau. These rheological characteristics suggest the existence of an effective yield stress arising from the presence of a percolated network. AFM images of high acyl gellan revealed micrometer-sized networks composed of double-stranded helices laterally associated to varying degrees. These associated helices did not dissociate fully on heating at 90°C, suggesting that they are partially preserved native networks secreted by gellan-producing bacteria.
Propolis is a resinous substance collected by honeybees from various plant sources. In this study, we examined the antioxidant properties of propolis from diverse geographic regions of Korea including Jeju Island. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant properties by β-carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization, and ferric reducing/antioxidant power assays. Furthermore, the major constituents in EEP were identified by HPLC analysis with a photodiode array and mass spectrometric detection, and each component was quantitatively analyzed. All propolis samples except that from Hongcheon, Iksan, Aewol and Pyoseon had relatively strong antioxidant activity accompanied by high total polyphenol contents. Propolis with strong antioxidant activity contained large amounts of antioxidative compounds, such as caffeic acid, kaempferol, phenethyl caffeate and galangin. On the other hand, propolis from Jeju Island had weak antioxidant activities and had only a few compounds in propolis from other regions.
Camu-camu (Myrciaria dubia, Myrtaceae) is a tropical fruit, and is known to be rich in vitamin C. The fruit is mainly used in juice or vinegar production, and large amounts of byproduct, composed of seed and peel, is generated as agricultural and industrial waste. Our studies on camu-camu seed and peel revealed that the seed contains large amounts of polyphenols (400 mg/g). Further studies on the seed resulted in the isolation of vescalagin and castalagin, C-glycosidic ellagitannins with a hexahydroxydiphenoyl group and a nonahydroxyterphenoyl group attached to the open chain D-glucose, as the main polyphenolic constituents. The structures of these tannins were characterized by their 1H- and 13C-NMR spectra and mass spectrum. The two C-glycosidic ellagitannins represent about 15% of the polyphenolics in the seed of camu-camu fruit, and are likely responsible for the anti-oxidative activity of the seed extract’s anti-oxidative activity.
Previously, it was clarified that myofibril gelation was enhanced by the basic protein glyceraldehyde 3-phosphate dehydrogenase (GPD). In this study, the mechanism of the gel-enhancing action of GPD to myosin B was evaluated through the study of the surface properties of GPD. GPD and myosin B were prepared from pork loin. Succinylated GPD (S-GPD) was successfully prepared without any loss of solubility at a weight ratio (succinic anhydrate to GPD) of 1.0. Though gelation of myosin B alone required a minimum protein concentration of 4.0% (w/v), the addition of GPD enhanced the gelation of myosin B at a concentration of 3.5% (w/v). Furthermore, GPD increased the gel strength drastically at concentrations above 4.5% (w/v). On the other hand, the addition of S-GPD did not improve the gelling property of myosin B. SDS-PAGE showed molecular interaction between GPD and myosin B, but not between S-GPD and myosin B. However, in the case of GPD, the GPD band became insoluble under coexistence of GPD with myosin B. Meanwhile, the myosin heavy chain was partially soluble. Furthermore, actin and GPD bands became thicker in the insoluble fraction after mixing of G-actin and GPD. These results indicate that positive charges on the surface of GPD are necessary to enhance the gelation of myosin B.
Four quality grades (excellent, good, acceptable, and “not acceptable”) of yellowfin tuna meat (Thunnus albacares), as judged by a professional appraiser, were compared based on the red/ox state and extractability of myoglobin (Mb). As a result, the metMb ratio of the “not acceptable” grade of meat was significantly higher than that of the other higher-grade samples. In contrast, the highest ratio of oxyMb was found in the “excellent” meat, followed by good > acceptable > “not acceptable” meats. Color measurement revealed significant differences in a* value between the different grades of meat, but showed essentially no difference in L* and b* values. Both a* value and redness index (a*/b*) showed high correlation coefficients with metMb ratio. Mb extractability tended to be higher in the higher grade of meat. In conclusion, the commercial appraisal of tuna meat quality was demonstrated to be reliable.
We screened suitable lactic acid bacteria (LAB) strains for use in fermented dairy products by analyzing milk fermented with 10 probiotic LAB strains from Mongolian dairy products. Lactobacillus paracasei paracasei strain 06TCa19 was selected because of its favorable effects on pH, lactic acid production, and viable bacterial numbers after fermentation of skim milk. Then, we prepared 06TCa19 and control fermented milks and conducted a randomized, double-blind crossover study with 46 healthy women to determine the effects of the strain on human defecation. The ingestion of 06TCa19 fermented milk improved the subjects’ fecal characteristics, including shape and color. Analysis of stool samples from 8 subjects revealed that L-lactic acid levels and Lactobacillus and Bifidobacterium numbers increased. Moreover, strain 06TCa19 was suggested to reach and survive in the intestines, and is, therefore, suitable for fermented dairy products and can potentially improve human defecation.
Aspergillus sojae generally has only one ortholog of the Aspergillus oryzae taa (α-amylase) gene. The AstaaG1 gene from a shoyu koji mold, A. sojae KBN1340, comprised 2,063 bp with eight introns. AsTaaG1 consisted of 498 amino acid residues possessing high identity to other Aspergilli α-amylase sequences. Disruption of the AstaaG1 gene resulted in no detectable α-amylase production in starch medium. Promoter activity of the AstaaG1 gene, monitored by xylanase activity, was upregulated with replacement of the CCAAT-like sequence. Site-directed mutation of the CCAAT-like sequence increased xylanase production approximately four times higher than that of the wild type. These results clearly demonstrate that the decreased copy number of the taa gene and the low affinity binding sequence to the Hap complex lead to the lower amylolytic activity of A. sojae compared to that of A. oryzae.
This paper reports the effects of umbelliferous plants on Cd-induced micronucleus formation in Cd-exposed mice. After ICR mice (7 w) were given free access to a 100 mg/kg Cd solution for 12 days, they were fed with a standard diet and a control diet supplemented with Petroselinum crispum (Pc) or Coriandrum sativum (Cs) for 70 days. Femoral bone marrow smears were prepared every 2 weeks, and micronucleus frequency was determined from the micronucleated polychromatic erythrocyte count. The micronucleus frequency obtained from the positive control group was approximately 2-fold higher than that in the negative control group (No Cd administration) (P < 0.05). However, micronucleus frequencies in the Cs and Pc groups were decreased by 21 − 60% (P < 0.05) compared to that of the positive control group. These results suggest that consumption of these two plants might inhibit genotoxicity and possibly even reduce the risk of aging and carcinogenesis induced by Cd.
In this paper, the feasibility of a modified oxygen radical absorbance capacity assay based on fluorescence (ORAC-FL) was evaluated. In the modified ORAC-FL assay, a large quantity of radicals is generated in a short period of time by photolysis of 2,2’-azobis(2-amidinopropane) dihydrochloride (AAPH), through illumination with ultraviolet light. Importantly, no heating is required to generate the radicals, while the time required to monitor the fluorescence intensity (FI) is shortened, owing to the rapid fluorescence decay. In this study, the optimal experimental conditions for the modified assay were determined and the antioxidant capacity of two samples was evaluated at room temperature using the modified assay. Although relative ORAC values were obtained, some aspects of the modified assay require further optimization for eventual practical use.
In this study, the rheological and flow properties of stirred yoghurt in a circular pipe as affected by casein and fat content were investigated. The structure breakdown of the stirred yoghurt was evaluated from the rheological measurements and compared with that estimated from pipe flow data through estimating the dimensionless structure number (Se) and Deborah number (De). The rheological tests revealed that increasing the casein and fat content led to increase the apparent viscosity of the stirred yoghurt and its dependence on shearing time. Both, the rheological and pipe flow tests revealed that the thixotropic behaviour of stirred yoghurt increased with casein and fat content, where the rate of structure breakdown of yoghurt in pipe flow was greater than the build-up rate. On the other hand, increasing the casein and fat content in stirred yoghurt resulted in an increase in the Deborah number (De), which means an increase in the elasticity of the yoghurt. It was shown in this work that the simple rheological tests can be used to estimate the structure breakdown rate of stirred yoghurt in pipe flow.
We obtained anti-allergic oligosaccharides from a sweet potato-shochu distillery by-product (SDB). Oral administration of oligosaccharides A and B in SDB to ovalbumin/aluminum-sensitized mice for 4 weeks resulted in a significant decrease in serum IgE concentration. The release of β-hexosaminidase from rat basophilic leukemia cell line RBL-2H3 was also suppressed by the addition of oligosaccharides A and B to the cell culture. The molecular weights of oligosaccharides A and B were about 730 and 530, respectively, determined from the retention time on Bio-Gel P-2. Oligosaccharide A was composed of galactose, glucose and uronic acid in a molar ratio of 2:1:1. Oligosaccharide B was composed of galactose, glucose and arabinose (1:1:1 molar ratio) or galactose, glucose and uronic acid (1:1:1 molar ratio), showing that oligosaccharide B is a heterogeneous mixture of other oligosaccharides. Oligosaccharides A and B exhibited growth-stimulating activity with Bifidobacterium lactis BB-12. The present results indicate that the oligosaccharides in SDB are promising ingredients for the effective control of allergic diseases via suppression of IgE production and inhibition of basophilic leukemia cells degranulation.
The influence of salt concentration on acid-induced gel formation and gel properties of silver carp myofibrils was investigated. Results showed that silver carp myofibrils were slightly soluble regardless of salt concentration in the presence of D-gluconic acid-δ-lactone (GDL). The increase of myofibrils solubility in the absence of GDL was mainly caused by the dissociation of myosin and actin, as evidenced by SDS-PAGE. Myosin and actin were the major protein components involved in acid-induced aggregation of silver carp myofibrils. Ca2+-ATPase activity and surface reactive sulphydryl (SH) contents of myofibrils with GDL addition were much lower than those in the absence of GDL. Significant decrease in total SH content of silver carp myofibrils in the present of GDL at salt concentration of 0.3 mol/L NaCl was observed, suggesting the contribution of disulphide bonds to the acid-induced gel formation. The gel properties of acid-induced silver carp myofibril gel were highly dependent upon salt concentration, and acidified myofibril gel with high gel strength could be obtained with addition of 1.7% − 2% NaCl.
Rice grains contain starch-degrading enzymes, including α-glucosidases, α-amylases, β-amylase, pullulanase and isoamylases. We investigated the distribution of these enzymes in raw rice grains, and their elution behavior during cooking in Nipponbare and Habutaemochi cultivars. Different distributions and elution behaviors were observed among the different cultivars. These results suggest that differences among cultivars with regard to activation and starch degradation by these enzymes during rice cooking should be taken into consideration.
The stability of wheat bran proteases for producing angiotensin I-converting enzyme (ACE) inhibitory peptides during storage was investigated. The aspartic proteinase activity upon storage at 15, 20, and 30°C was > 90% of initial levels after 30 days, while storage at 40 and 50°C resulted in levels of 87.3 and 63.1%, respectively. The carboxypeptidase activity remained constant at all temperatures during the storage period. The yields of ACE inhibitory peptides from wheat bran at 15, 20, 30, 40, and 50°C after 30 days were 99.0, 98.0, 97.1, 97.1, and 92.2% of the initial level, respectively. The ACE inhibitory activity of all fractions was > 95% of the initial level. These results indicated that the storage of wheat bran at 15 to 40°C results in maintenance of the ACE inhibitory peptide-producing activity, for at least 30 days.
The present study was designed to characterize melanoidins in soy sauces and fish sauces by the determination of 3-deoxyglucosone (3-DG) and 3-deoxypentosone (3-DP), which are intermediate reaction products in the formation of melanoidins. 3-DG was determined in 10 (93.20 − 497.60 μg/mL) out of 13 soy sauce samples and in 5 (6.40 − 291.20 μg/mL) out of 11 fish sauce samples. 3-DP was found in 6 samples (36.40 − 1053.60 μg/mL) out of 13 soy sauce samples and in 3 (20.40 − 288.40 μg/mL) out of 11 fish sauce samples. The greater the amount of 3-DG, the higher color intensity in fermented soy sauces of Japan, Korea, and Taiwan. However, in some soy sauces of China, Philippines, and Singapore, there was no correlation between the amount of 3-DG and color intensity, due to the addition of caramel pigments. Additionally, the content of 3-DP was closely related to color intensity, and 3-DP had a lesser effect on color than 3-DG.
Biofilm is a niche which protects microorganisms from detergent treatment and keeps them a persistent infection source. The aim of this study was to assess the effect of Ethylenediaminetetraacetic acid (EDTA) in vitro on adhesion, formation and eradication of S. aureus biofilm using microtiter plate assay on the surface of biomaterials made from polyvinyl chloride (PVC). Results showed that (1) In the early stage of biofilm formation, adding 0.1 mM of EDTA would strongly inhibit biofilm formation, but after 72 h the inhibition disappeared; (2) Saturating EDTA with excess of cations had no significant effect on the formation of biofilm, indicating the biofilm inhibition had nothing to do with the chelating properties of EDTA; (3) EDTA was shown to inhibit cell-to-surface interactions and cell-to-cell interactions, which at least partially contributed to the repressed initial adherence. The study suggested that EDTA could inhibit the biofilm formation in the early stage by affecting the initial adherence of Staphylococcus aureus cells.
This study developed kinetic models to predict the fate of Staphylococcus aureus in sauces. S. aureus was inoculated in Carbonara and Octopus sauce. Total bacterial and S. aureus cell counts were enumerated during storage. Growth data were fitted to the Baranyi model to calculate growth parameters. The parameters were then fitted to secondary models, and dynamic models were developed. Root mean square error (RMSE) was calculated for model validation. Growth of total bacteria and S. aureus was observed in Carbonara and Octopus sauces. Goodness of fit for primary, secondary model, and dynamic model was good. In addition, the developed model had acceptable performance (RMSE: 0.326 (Carbonara), 0.361 (Octopus sauce)). The results indicate that the developed models for Carbonara and Octopus sauces should be useful in predicting S. aureus growth.