The aim of this study is to investigate the change in microbiological, physicochemical and sensory properties of freshly-squeezed pomegranate juice using ultrasound and/or natamycin as an alternative to pasteurization. Samples were pasteurized (80 °C, 2 min), sonicated (60% amplitude, 26 KHz, 80 W, 5 min), treated with natamycin (12.5 ppm) and stored at 4 °C for one month. Pasteurized pomegranate juice was not significantly changed in terms of pH, Brix, titratable acidity and total phenolic (µg gallic acid equivalent. mL−1) values compared to the treated samples (p > 0.05). During storage, ultrasound-processed pomegranate juice retained more than 90% total monomeric anthocyanins. Microbial values showed a reduction in load at a level acceptable for the general quality parameters. In the sensory analysis, the general evaluation was accepted as ultrasound and/or natamycin. This study emphasizes the potential application of ultrasound and/or natamycin to increase the functional value of pomegranate juice.
Palm date seeds can be a potential source to prepare a decaffeinated coffee-like brew and to produce oil. Hence, the objectives of this work are to model the changes in colour and hardness of date seeds during roasting process, as well as to study the effects of roasting conditions on the total specific grinding energy and the oil extraction yield of the seeds. General reaction models and general regression equation were applied to simulate the changes in colour, hardness, oil extraction yield, and total specific grinding energy during roasting process. The outcomes showed that the colour parameters (L*-value and b*-value) and the hardness of the roasted date seeds can be satisfactorily described by the first-order equation, while a*-value and ΔE were adequately defined by the zero-order model. A decrease in total specific grinding energy and an increase in oil yield were recorded as the roasting temperature and time were increased. Hence, this study concludes that the roasting of date seeds at 200 °C for 30 min generates the lowest grinding energy and a high amount of oil.
n-3 Polyunsaturated fatty acids (PUFAs) have important physiological functions. Encapsulation by spray drying is a technique used to protect against oxidation of PUFAs. The present work aimed to investigate the effect of starch coating on the oxidation stability of spray-dried powders containing fish oil droplets.
A mixture (wall material content: 22 wt%) containing maltodextrin (MD, dextrose equivalent (DE) = 25)) or sucrose, hydrolyzed casein (4 wt%), antioxidants (4 wt%) dissolved in water (40 wt%) and fish oil (30 wt%) was homogenized at 100 MPa using a high-pressure homogenizer. The emulsion was spray-dried into powders using a pilot-scale spray dryer with and without starch feeding near the atomizer. The apparent oxidation rate constant depended significantly on the surface-oil content and was larger for the MD-coated fish oil than for the sucrose-coated fish oil.
Wood ear (Auricularia polytrica) powder (WE) was used to substitute 10%–40% of wheat flour to make icebox cookies. Contents of fiber, polysaccharide, and total phenols in WE were 2.73%, 66%, and 2.49%, respectively. Hunter L, a, b, hardness, moisture, and water activity of cookies decreased with the increased WE percentages, while ash and carbohydrate contents showed a reverse effect. With the increased WE replacement, dimension of cookies became shorter, narrower and thicker. Total phenols content in WE40 extract was the highest among extracts, and had the best effect on 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. On a seven-point hedonic test, the score of color, sweetness, hardness, flavor and overall liking of cookies made with 0%–30% replacement of wheat flour with WE were moderately acceptable. Overall, a partial replacement of wheat flour with WE in cookies making could be developed as a novel food with more bioactive components and effective antioxidant activity.
Kinetic analysis was performed for the isomerization of glucose and side reactions (decomposition) in subcritical water with low-to-high saccharide concentrations (0.001–0.40 kg/kg-water). An aqueous solution of glucose was treated under subcritical conditions at 200 °C for 30–400 s using a tubular reactor. Isomerization of glucose to fructose predominantly occurred when the glucose concentration was low, while isomerization to mannose scarcely occurred. Decomposition of glucose to byproducts was promoted with increasing glucose concentration, while the isomerization was suppressed. Selectivity of fructose and mannose for the isomerization became lower at higher glucose concentrations and with longer reaction times. Kinetic analysis of the reaction indicated that the decomposition step of fructose most greatly affected the selectivity of fructose during the subcritical water treatment of glucose.
Whipped cream consists of air bubbles, fat-globule aggregation, and a water phase; thus, knowledge of the effects of foam and fat-globule aggregation is important in understanding the physical properties of the produced whipped cream. A 45 (wt%) fat-content dairy cream and a batch whipping machine were used in this study to explore the shape-retention ability. The mean diameter of bubbles was also measured in optical microscopy images to evaluate the effects of bubble size. In constant-beating-speed tests, increasing the beating speed decreased the whipping time and overrun, which increased the shape-retention ability. On the other hand, changing the beating speed during the whipping process maintained a high shape-retention ability while reducing the whipping time. A high initial overrun might induce a shape-retention ability at a constant beating speed, and small initial bubbles might maintain a high shape-retention ability.
Preparation of GABA (γ-aminobutyric acid)-rich sourdough using rice bran and raisin was investigated. Preparation of sourdough began with pre-fermented raisin liquid, which is a widely used source of wild yeast and lactic acid bacteria. The number of naturally occurring cells in the liquid was 3.5×107 CFU/mL for yeast cells and 3.4×107 CFU/mL for lactic acid bacteria. The liquid was added to rice bran and then used to make sourdough via a three-stage fermentation process for 42 hours. The numbers of yeast (2.1×108 CFU/g) and lactic acid bacteria (1.3×108 CFU/g) in sourdough increased gradually with repeated fermentation. We also confirmed that the GABA and polyphenol contents of sourdough significantly increased during fermentation. Thus, sourdough enriched with GABA could be rapidly and easily obtained through a three-stage natural fermentation process using rice bran and raisin. These findings also provide useful information for the effective use of milling rice by-products.
Ursolic acid (UA) has been implicated as one of the major components of traditional medicinal plants. In this study, we investigated the effect and mechanisms of UA, by comparison with other triterpenes, Glycyrrhetic acid (GA), Oleanolic acid (OA), Uvaol (Uv) and alpha-amyrin on the vascular cell adhesion molecule-1 (VCAM-1) in Human Umbilical Vein Endothelial Cells (HUVECs). UA inhibited the induction of the VCAM-1 expression in a dose-dependent manner after stimulation with TNF-alpha, whereas GA and OA did not show any inhibitory effect. Furthermore, UA inhibited the adhesion of HL-60 to the TNF-alpha-stimulated HUVECs. The activity difference indicated that the ursane structures with a highly polar group at the 28-position are critical components of UA for regulating the VCAM-1 expression. These results suggested that the anti-inflammatory effect of the triterpenes might depend on their chemical structure.
In this study, the preventive effects of Lactobacillus plantarum CQPC07 (LP) on dextran sodium sulfate (DSS)-induced male C57BL/6J mice colitis were investigated. The results showed that LP can increase the colon length and decrease the ratio of colon weight/colon length in DSS-induced colitis mice. Analyses of the sera of mice showed that LP can reduce the level of serum endothelin (ET), substance P (SP), and interleukin-10 (IL-10), enhance the activity of somatostatin (SS) and vasoactive intestinal peptide (VIP), and increase the levels of IL-2. Biochemical analyses of colonic tissues from mice showed that LP can increase the levels of glutathione (GSH), superoxide dismutase (SOD), and decrease the level of myeloperoxidase (MPO), malondialdehyde (MDA). A pathological tissue evaluation showed that LP can inhibit colon tissue damage in DSS-treated mice. Furthermore, LP can also increase neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), c-Kit, stem cell factor (SCF) mRNA expression and decrease inducible nitric oxide synthase (iNOS), IL-8, and C-X-C motif chemokine receptor 2 (CXCR2) mRNA levels in the colon tissues of colitis mice. Thus, LP has a colitis inhibitory effect, the higher the concentration, the better the effect, and the effect of high concentration of LP is close to the drug of sulfasalazine.
The effect of soaking treatment before cooking on the hardness of soybeans and red kidney beans stored at 37 °C/75 % RH (aged beans) was evaluated by kinetic analysis using the softening rate constant. Based on the analysis results, softening behavior was separately examined as “softening due to water absorption” and “softening due to heating”, making it possible to predict the heating time and to quantitatively evaluate the effect of soaking treatment on hardness during cooking of beans. Interestingly, in both aged beans, prolonged soaking time remarkably suppressed softening during subsequent heating. In addition, in both aged beans, when the soaking time was longer, the value of the softening rate constant ks1 for pre-soaked beans decreased and the difference in the predicted heating time between pre-soaked and un-soaked beans was reduced. These results indicated that soaking treatment before cooking is not recommended for stored beans, as it suppresses their softening during cooking.
Multi-grain koji (MGK), an enzyme-rich food, is produced by solid-state fermentation of a mixture of seven types of grains. In this study, we aimed to assess the effects of MGK on body composition in rats fed a high fat diet, and in young women. Twenty human participants had a body fat percentage >28 %. These participants were blindly divided into test and placebo groups, with 0.5 g/day of MGK and autoclaved (inactivated) MGK consumed, respectively. The weights of liver and visceral fat were lower in rats fed a high-fat diet supplemented with MGK than those provided the autoclaved MGK. After 3 months, body weight and body mass index, and the percentage of body fat (in test group only) were significantly reduced compared to the values recorded before MGK intake. Thus, we demonstrate that MGK supplementation is effective in decreasing body fat in women.
Accumulation of reactive oxygen species (ROS) in the culture medium may inhibit the growth of microorganisms and prevent the detection of harmful bacteria in foods. In this study, we investigated the relationship between ROS (hydroxyl radical and hydrogen peroxide) and Escherichia coli growth using electron spin resonance, which detects and quantifies multiple oxygen free radicals simultaneously. ROS had little effect on the growth of normal E. coli cells. In contrast, heat-treated E. coli cells were sensitive to ROS, and the number of colony-forming units increased 10-fold with the addition of sodium thiosulfate or sodium pyruvate, both of which scavenge ROS in the culture medium. Both compounds efficiently scavenged hydroxyl radical, while sodium pyruvate eliminated hydrogen peroxide to a greater extent than sodium thiosulfate. Our results imply that hydroxyl radical levels are more critical for the growth and survival of damaged E. coli cells.
Wasabi (Wasabia japonica Matsumura) is a perennial plant, and its rhizome is widely used as a pungent spice. Wasabi rhizome has been reported to have various physiological activities, but the flower has not been studied in depth. The aim of the present study was to isolate compounds from wasabi flowers and clarify their antioxidant and anti-inflammatory activities. Three phenylpropanoids, one alkaloid and seven flavonoids were isolated from wasabi flowers. Among them, 2″-O-trans sinapoyl isovitexin was identified as a novel compound. Five compounds inhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, with IC50 values of less than 100 µM. Luteolin isolated in this study was found to inhibit nitric oxide production in macrophage-like J774.1 cells, with an IC50 value of 24.1 ± 4.4 µM. Our results indicate that the phenolic compounds in wasabi flowers are effective ingredients for antioxidant and anti-inflammatory activities. For these reasons, wasabi flowers are expected to be used effectively as a functional food.
Various secondary metabolites with antioxidative effects have been reported to exist in Phellinus igniarius. However, the trace quantity of these metabolites in normal fermentation conditions deeply limits its medical values and potent clinical application. Some elicitors such as bioinducer and chemical inducer can improve the productivity of secondary metabolites which have certain biological activities in plants and fungus. In this study, nitrous acid (NA) and diethyl sulfate (DES), as potent killing and mutagenic chemical agents, to treat P. igniarius and enhance the metabolites contents. The variation of biomass, metabolite production, enzyme activity, and antioxidant efficacy of two mutant strains were investigated. The mutant strains exhibited better viability and produced more secondary metabolites. Altogether, these results indicate that chemical mutagenesis is an effective strategy to obtain high-activity mutant strains of P. igniarius with high yields of total flavonoids and total polysaccharides, the main constituents with antitumor and antioxidant activities.
We have reported that the ingestion of a drink including winter savory extract (WSE) has an effect on core body temperature (CBT) and body surface temperature (BST) in people who experience cold sensitivity. In this study, to elucidate how the swallowing process contributes to changes in CBT and BST, experiments comparing the effects of WSE-drink and WSE-capsule were performed. We showed that a small amount of WSE-capsule did not affect CBT and BST, but WSE-drink (containing an equal amount of active principles in the WSE-capsule) induced significant changes in peripheral BST without changes in CBT. Moreover, WSE-drink with a higher concentration but equal amount of active principles induced significant changes in both CBT and BST. These results suggest that neurostimulation in the swallowing process after drinking WSE might greatly contribute to heat production and heat transfer (which is caused by peripheral vasodilation) independently of each other.
Escherichia coli cells suspended in phosphate-buffered saline (PBS) were treated by high hydrostatic pressure (HHP; 400 – 600 MPa) at 25 °C for 10 min and then stored at 5 – 25 °C. When treated at 600 MPa, the cells were inactivated lethally. Treatment at 400 and 500 MPa reduced viable cell counts by approximately 7 and 8 log, respectively. Viable counts of cells treated at 400 or 500 MPa increased obviously during storage at 15 and 25 °C, whereas they did not increase at 5 and 10 °C. Meanwhile, healthy E. coli cells inoculated to a heat-killed dead cell suspension in PBS showed drastic growth during storage at 15 and 25 °C, but no growth at 5 and 10 °C. Therefore, the obvious increase in viable counts of HHP-treated cells might be attributed to their cannibalism of the dead cells.