The effects of physical modification methods, superfine grinding (SG) and high-pressure processing (HPP), on the physical and chemical properties of mushroom (A. chaxingu) powders were investigated. Scanning electron microscope observations revealed the shape and surface morphology of mushroom powders. The SG powder had smaller particle size and greater bulk density. The HPP powder had lower viscosity and a smaller angle of repose. The SG and HPP powders exhibited a water holding capacity of 3.82 g/g and 3.62 g/g, while the water solubility index was 32.6% and 28.3%, respectively. The chemical analysis indicated greater soluble dietary fiber (SDF) contents (9.63 g/100 g and 7.00 g/100 g), protein solubility (2.51% and 2.25%) and polysaccharide solubility (4.92% and 3.56%) in the SG and HPP powders, respectively. Overall, the application of SG and HPP may provide two novel approaches to achieve greater protein, SDF and polysaccharide contents with desirable properties.
Sorbitol could lower the viscosity, yield stress, flow behavior index, storage modulus, loss modulus, and elevated the consistency index, loss tangent of peanut butter. It made peanut butter have greater mobility and more obvious liquid characteristic. Sorbitol could reduce the hardness and stickiness of peanut butter, thereby solving the problem of poor spreadability of traditional (stability) peanut butter. The microstructure of the sorbitol added peanut butter system was well-distributed and more compact. It had a higher degree of adhesion, a stronger shear resistance and anti-thixotropy. Sorbitol could enhance color and aroma of peanut butter, make its texture condition more uniform and taste more delicate. More importantly, the peanut butter with sorbitol was easier to spread on the food, and the coating was more smooth and uniform. On the whole, the peanut butter sample with 9% sorbitol added had the best sensory quality.
To reduce the amount of salt added during the production of takanazuke, two isolated bacterial strains, B17-4 (Lactobacillus (para) plantarum) and C120-3 (Pediococcus parvulus), were used as starter strains. Takanazuke with bacterial starter was incubated with 2% (w/w) NaCl, and 6% (w/w) NaCl was added to takanazuke without starter as a control. Takanazuke was incubated at the average monthly temperatures in the Aso region (10.8 – 25.0°C). pH decreased to 4.3 with strain B17-4 and 4.2 with strain C120-3 after 12 days, while it decreased gradually to 4.2 without a starter strain after 40 days. Strain B17-4 produced less lactate and assimilated less reducing sugar than strain C120-3, which seemed to depend on the production of extracellular polysaccharide by strain B17-4. In takanazuke with starter strains and 2% (w/w) NaCl, both B17-4 and C120-3 were dominant in culture during the 181-day study.
Response surface methodology (RSM) was applied to predict optimum conditions for microwave-assisted extraction (MAE) of crude water-soluble polysaccharides from Piteguo fruit (PTG). A central composite design was used to optimize microwave power (X1: 400 – 600 W), extraction time (X2: 5 – 10 min) and ratio of water to material (W/M ratio, X3: 30:1 – 50:1 mL/g) to obtain a high crude polysaccharides yield. The statistical analyses indicated that all of the three factors had significant effect on the extraction yield of crude polysaccharides (p < 0.001). The results showed that the extraction ratio of crude polysaccharides was up to 7.86% under the optimum extraction conditions as follows: microwave power 550 W, extraction time 9 min, W/M ratio 45 mL/g, which was consistent with the predicted models with the coefficients of determination (R2) of 0.9809.
The disinfection efficacy of sodium hypochlorite (NaClO) and chlorine dioxide (ClO2) was evaluated singly or in combination with micro-bubbling, ultra-sonication, or mild heat (50°C) against microorganisms on lettuce, spinach and Chinese cabbage. There were no significant differences in reductions of either intrinsic microflora or inoculated Escherichia coli O157:H7 between 5 and 10 min of treatment time, between 50, 100, 200 ppm NaClO, or between 25 and 50 ppm ClO2. However, mild heat (50°C) significantly enhanced efficacy, with maximum log reductions of 2.91 in total plate count, 4.10 in total coliform count, and 2.13 – 2.53 in E. coli O157:H7. Heat was more effective when applied before or with chlorination than after. The concentration and efficacy of the chlorine wash water gradually decreased with reuse, allowing cross-contamination when the initial concentration was less than 50 ppm. These results can be used to guide the fresh-cut vegetable industry in designing chlorine-based treatments for better control of safety and quality.
Changes in total chlorophyll and ascorbic acid (AsA) contents and total color difference (TCD) of blanched green bell peppers during hot air and microwave drying were investigated. The dehydration kinetics of unblanched and blanched green bell peppers at 60°C were determined. Total chlorophyll and AsA contents as well as TCD were determined in the range of 40 – 70°C for hot air drying and 500 – 800 W for microwave drying. The decomposition rates of total chlorophyll, AsA and TCD followed first order reaction kinetics. Each rate constant exhibited an Arrhenius-type temperature dependence. The activation energies (E) of total chlorophyll, AsA contents and TCD were determined for hot air drying.
This study aimed to determine the color and texture profile of instant desserts produced from mixtures of pregelatinized flour of broken-rice grains, milk powder and sugar. A simplex design with seven different formulations of instant dessert and two replicates at the central point was used. Proximate composition, microbiological safety and acceptance of dessert selected (with greater desirability) were also determined. The texture attributes are changed depending on the amount of pregelatinized flour, milk powder and sugar used, in this way, different formulations can be used according to each texture desired. The ideal formulation of white chocolate instant dessert consisted of 39.6 g (100 g)−1 pregelatinized flour, 25.5 g (100 g)−1 sugar, 22.8 g (100 g)−1 milk powder, 10 g (100 g)−1 flavor and 2 g (100 g)−1 gum. The instant dessert with pregelatinized rice flour presents textural, nutritional, microbiological and sensory characteristics satisfactory, and is a good alternative to commercial instant desserts based on modified corn starch.
In this study, the specific mechanical energy (SME) response of a dry type single screw extruder (Length to Diameter ratio (L/D) 12:1, Compression Ratio (CR) 4.5:1) developed locally was investigated for maize, cassava and wheat flour processing. The study was necessitated by the need to provide management data for the preliminary studies of the extruder A factorial experiment in completely randomized design was employed to study the effect of extrusion variables: feed moisture (25 – 50%), extruder temperature built up by varying the duration of sampling (2 – 30 min) and screw speed (100, 150, 200 rpm) on SME. The study revealed that SME varied directly with duration of operation for cassava products and inversely with duration of operation for all maize and wheat products. SME increased with increasing speed from 100 to 150 rpm but decreased at 200 rpm. SME increased with increase in moisture content from 25 to 40%.
In this paper, we determined appropriate degree of dephosphorization of carp eggs before trypsin hydrolysis according to the degree of hydrolysis and calcium binding activity, and purified a novel oligophosphopeptide with high calcium binding activity from carp eggs hydrolysate. The results showed that dephosphorization treatment can significantly increase the degree of hydrolysis (p < 0.05). However, hydrolysate of DP2 with 30.39% degree of dephosphorization owned the strongest calcium binding ability of 0.67 mmol/g-protein, and excessive dephosphorization was disadvantageous. After ultrafiltration, 88.73% content of hydrolysates was the fraction U1 with MW < 3 kDa which showed better ability to bind calcium. After hydroxyapatite chromatography, H3 eluted with the maximum concentration of phosphate buffer (400 mM) exhibited the highest calcium binding ability of 6.63 mmol/g-protein. Amino acid content analysis showed that the Ser content of H3 is about 2.5 times more than that of U1 but the contents of Thr and Tyr are almost identical. Further purification using size exclusion chromatography and high-performance liquid chromatography, an oligophosphopeptide with high calcium binding ability (7.85 mmol/g-protein) was obtained. Its sequence was identified as (pS)-S-(pS)-A-F-(pS)-(pS)-E-L-A-R through ESI-QTOF tandem mass analysis. It is possible to provide utilization of fish eggs as a novel calcium nutraceutical additive in food industry.
The purpose of this study was to investigate the common components and characteristic compounds of whole milk powders (WMPs) produced in three different regions of Asia and Oceania. The volatile components were isolated from seven WMPs produced in Japan, New Zealand, and China. Forty-one aroma-active compounds were detected in these volatile components using gas chromatography-olfactometry by the detection frequency method. The binary data converted from the detection frequency values was applied to the principal component analysis (PCA) and hierarchical cluster analysis (HCA). The HCA result showed three clusters corresponding to the production regions. Based on the PCA, approximately 70% of the total variance of WMPs was explained by the PC1 and PC2 scores. The PC1 scores can be used to examine the property of WMPs based on the aroma of dairy products and the PC2 scores indicated the property of the production region based on the scattering plot of each WMP. Based on the PC2 loading values of aroma-active compounds, it was revealed that, depending on the production region, the difference between the whole aromas of different WMPs was caused not by the characteristic compound, but by the balance of aroma impact compounds that commonly occur in WMPs.
Effect of direct current on the functional properties of batter made from soft-wheat flour was studied to establish a new processing method for food. Soft-wheat batter was processed with direct current (30 mA) and was separated into anode side and cathode side from the middle. The anode and cathode side samples were each kneaded six times for thirty seconds per. Batter viscosity was measured with a rotation viscometer after each kneading. After kneading, the viscosity of the anode side sample greatly increased with increasing electrical processing period. To elucidate the cause of this change, the processed batter was lyophilized and then extracted with water. The amount of extracted protein detected by the Bradford method increased with increasing period of electro-processing, especially in the anode side sample. Sodium dodecyl sulfate gel electrophoresis showed the increase of protein bands was attributable to glutenin macropolymer (GMP) in the extracted substance. Microscopic observation showed that the solubilized protein re-combined to make a protein matrix that captured starch granules.
Oral administration of Lactobacillus reuteri CP3012 or Lactobacillus acidophilus L-92 for 60 days in rats that were previously administered 3,3’,4,4’,5-pentachlorobiphenyl (PCB126) orally at a dose of 100 µg/kg of body weight resulted in a significant decrease in hepatic bioaccumulation of PCB126 (p < 0.05), with levels of 30.7 ± 3.7 ng/g and 92.6 ± 25.0 ng/g of liver tissue, respectively, compared with 133.1 ± 12.7 ng/g of liver tissue in the controls. The electron paramagnetic resonance signal level of the liver PCB126-specific g = 2.49 species in rats administered L. reuteri CP3012 decreased significantly (p < 0.05). Both the bile acid concentration in the feces and total stool output increased significantly following administration of lactobacilli (p < 0.05); however, adsorption of PCB126 onto the bacterial cells was not observed. These results suggest that these bacteria inhibit reabsorption of PCB126 with bile acid by blocking enterohepatic circulation through absorbing and/or deconjugating the bile acids in the intestinal tract and by promoting excretion of bile acids from the body, thus reducing PCB126 accumulation in the liver.
In this study, on screening mammalian DNA polymerase (pol) inhibitors from the extracts of 20 edible plants, we found that leaves of rosemary (Rosmarinus officinalis L.) showed the strongest pol inhibition; furthermore, we isolated four components, carnosic acid, carnosol, ursolic acid, and rosmarinic acid, from an extract of the leaves. Carnosic acid inhibited the activities of all 11 mammalian pols tested. In descending order of their inhibitory effect on pol λ, which is a DNA repair/recombination pol, the four compounds ranked as follows: carnosic acid > ursolic acid > carnosol > rosmarinic acid. The inhibition of pol λ by these compounds was significantly correlated with both in vivo anti-inflammatory and antiallergic effects, including on 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory mouse ear edema, and immunoglobulin E-induced passive cutaneous anaphylactic reaction in mice. These results indicate that rosemary and its constituent, carnosic acid, are potential therapeutic food candidates for inflammatory and allergic diseases.
Vitamin A acetate is used in fortified food widely. Due to the conjugated double bonds and ester functional group, it is susceptible to light, heat, oxygen and peroxide, resulting in changes in molecular structure and performance. The impact of peroxide on vitamin A acetate in octane solution with the addition of isopropylbenzene hydroperoxide (CHP) in the absence of light and oxygen at 90°C was investigated. By means of HPLC-DAD, GPC and HPLC-MS, it was found that vitamin A acetate was depleted after reaction for 18 days, and the main products were dimers. The reaction mechanism was proposed as follows: CHP homolysed to free radicals, and then abstracted α-H from vitamin A acetate to generate vitamin A acetate free radical, which added to another vitamin A acetate to form dimer free radical, at last dimer free radical abstracted α-H from vitamin A acetate molecule to form dimer product. Furthermore, four most probable dimer product structures were elucidated.
With the purpose of using Narazuke lees as a functional foods material, its effect on fatty liver of rats fed a high-fat and high-cholesterol diet was investigated. While significant accumulation of triacylglycerol was observed in the liver of rats fed high-fat and high-cholesterol diet was observed, rats fed diet supplemented with Narazuke lees showed significantly increased fecal dry weight, as well as increased fecal excretion of total lipids and total bile acids. Further, free fatty acids, glucose and insulin concentrations in the blood were significantly decreased, and amelioration of insulin resistance was observed. In the liver, reduction of FAS activity, significant increase in CPT-Ia activity and promotion of fatty acid β-oxidation were observed. An improving effect on fatty liver was observed by the suppression of lipid accumulation. The amount of liver TBARS was significantly reduced, indicating the inhibition of NASH progression.
We examined the change in the content of pectic substances in tea leaves during the steaming of green tea. In four cultivars of tea leaves, water-soluble pectin (WSP) content increased with steaming time, whereas the dilute hydrochloric acid soluble pectin (HSP) content remained almost constant. A β-elimination reaction proceeds throughout the steaming process, so it was postulated that some water-insoluble forms of pectin in HSP convert to a water-soluble form via β-elimination degradation with increasing steaming time. When tea leaves were steamed, pectin fractions with a molecular weight of 1,100 × 103 were degraded from water-insoluble HSP and eluted as WSP. Additionally, as steaming time increased, the fraction of smaller molecular weight pectin increased.
Bacterial diversity of the aged and aging pit mud from Luzhou-flavor liquor distillery was investigated and compared by molecular methods. Two bacteria-specific 16S rRNA gene clone libraries were constructed and analyzed using the amplified rRNA gene restriction analysis. A total of 172 clones were studied and 23 operational taxonomic units (OTUs) were obtained. Firmicutes and Chloroflexi predominated in the aged pit mud while Firmicutes and Bacteroidetes predominated in the aging pit mud. What is more, Chloroflexi and Actinobacteria were only detected in the aged pit mud. Additionally, the results of quantitative real time PCR (qPCR) showed that the quantity of Actinobacteria in the aged pit mud was 29 times as much as in the aging pit mud (P < 0.05). The results have compared the bacterial diversity of the aged and aging pit mud for the first time and maybe useful to further understand the microorganism of pit mud.
Simplified methods to purify major peanut allergens (Ara h 1, Ara h 2, and Ara h 3) were investigated to facilitate current laborious and time-consuming conventional purification methods, the combination of ammonium sulfate fractionation (ASF) and successive column chromatographic separations. Crude peanut proteins obtained from defatted peanut were subjected to ASF at higher concentrations of ammonium sulfate than those in conventional methods and then dialyzed against water. Purified Ara h 1, Ara h 2, and Ara h 3 were obtained by ultrafiltration(s) of the dialyzed supernatant in ASF (80 – 90%), the dialyzed precipitate in ASF (40 – 50%), and the dialyzed precipitate in ASF (0 – 40%), respectively. The purities of Ara h 1, Ara h 2, and Ara h 3 were 91.3%, 86.4%, and 93.9%, respectively. The simplified methods enable the purification of the three major peanut allergens in a relatively short time without the use of chromatographic separation techniques.
With regard to important changes in chemical composition, germination can be considered a valuable processing technique for modifying nutrient components of legume seeds. In this study, the changes in major chemical composition of peanut seeds were evaluated during short-term germination. The contents of water, minerals, aspartic acid, methionine, proline, folic acid, thiamine and total phenolics increased dramatically in peanut cotyledons and sprouts after germination, while the fat, riboflavin and ascorbic acid contents decreased markedly. The content of total amino acids, moreover, showed no obvious decrease, and the relative amount of some limiting and essential amino acids clearly increased after germination in peanut seed. This suggests that sprouts produced from peanut seeds could serve as a healthy food containing low fat, high levels of minerals and flavonoids.
In this study, 50% ethanol extract prepared from dry leaves of eight plants grown wildly in Mongolia were characterized for DPPH radical scavenging activity, ABTS radical cation scavenging activity, superoxide anion scavenging activity, ferric reducing power, iron chelating ability, and content of total phenol, flavonoid, and flavanol in order to find good sources of natural antioxidant from plant kingdom. Correlation coefficients between antioxidant parameters and contents of polyphenolic compounds were also calculated. Among them, leaves of Vaccinium vitis-idaeae, Paeonia anomala, Rosa acicularis, and Hippophae rhamnoides were rich in polyphenolics and exerted strong scavenging activity against DPPH radical, ABTS radical cation, and superoxide anion and reducing power.
The spoilage and pathogenic bacteria in the sporadic microbial spoilage of Sichuan Pickle were investigated by 16S rRNA libraries. The pathogenic Vibrio penaeicida (39.19%), the spoilage and pathogenic Pseudomonas fluorescens (6.76%) were detected in initial spoilage stage. While, in middle spoilage stage they shifted to the pathogenic V. penaeicida (51.25%), the spoilage and pathogenic Pse. fluorescens (3.75%), the spoilage Pse. Chlororaphis (7.5%) and then to the pathogenic V. penaeicida (30.59%), Halomonas variabilis (10.59%) and Arcobacter marinus (5.88%), the spoilage Lactobacillus alimentariu (5.88%) in latter spoilage stage. The undesired Pseudoalteromonas nigrifaciens, Psychrobacter alimentarius, Marinomonas, Cobetia marina, Celerinatantimonas and V. litoralis were also detected in the spoilage process. When compared at species level, the community similarity coefficients of three samples were from 0.6122 to 0.5165 and ascended to 0.2359. These results are very useful to design the effective strategies to control or eliminate the microbial spoilage of Sichuan Pickle.
A total of 270 food samples were obtained from twelve free markets (149 samples) and seven supermarkets (121 samples) in Thailand from September 2010 to February 2012. The samples were divided as follows: 51 meat, 37 fish/seafood, 38 vegetable, 11 fermented food and 133 tofu samples. The samples were examined for the presence of Salmonella spp.. Salmonella spp. were detected in 28% of the free market samples and in 7% of the supermarket samples. Meat samples had the highest contamination rates: 78% of the free market and 40% of the supermarket samples. Of the fish/seafood, vegetable, fermented food and tofu samples from the free markets, 41%, 6%, 25%, and 7%, respectively, tested positive for Salmonella spp., whereas the corresponding contamination rates were 5%, 5%, 0% and 0% for the supermarket samples. The resistance of the isolates towards sixteen antibiotics was tested. A high percentage of the isolates were resistant to streptomycin, tetracycline or ampicillin: 78%, 59% and 51%, respectively. In total, 152 isolates were resistant to at least one antibiotic, and of these, 98 (64%) were resistant to at least three antibiotics (multidrug-resistant). The most frequently isolated serovars were Corvallis, Rissen and O4: i:-. Random Amplified Polymorphic DNA (RAPD) was used for grouping 149 isolates into five groups. The grouping of the isolates is baseline information to emphasize the usefulness of subtyping Salmonella spp. isolated from several categories of retail foods obtained from free markets and supermarkets by using antibiotic resistance studies and RAPD grouping.