Cokelek cheese is a very popular dairy product in Turkey. It is produced mainly by boiling of set yoghurt made from cow's milk and then straining in a special cloth bag. In the present work, Cokelek cheeses were manufactured from cows’ milk by fermenting with different starter cultures (yogurt bacteria, Lactobacillus helveticus or mixture of these bacteria), and then denaturing at two different temperatures (85°C or 95°C), to asses the effect on yield, chemical and sensory properties of the products. The yields of Cokelek cheeses coded Y95:C, Y85(inoculated with yogurt culture and heated at 85°C), M95, M85 (inoculated with yogurt culture and L. helveticus (1:1), and heated at 85°C or 95°C), H95 and H85 (inoculated with L. helveticus, and heated at 85°C or 95°C) was found as 19.27 ± 0.21%, 19.78 ± 0.18%, 16.59 ± 0.76%, 18.69 ± 0.39%, 19.71 ± 2.17% and 19.88 ±0.25%, respectively. Statistically, no significant difference (p>0.05) was observed among the TA %, TS %, fat/TS % and salt/TS % level of the samples during storage period. At the 45th day, the saturated fatty acid (SFA)%, total unsaturated fatty acid (TUFA)%, monounsaturated fatty acid (MUFA)% and polyunsaturated fatty acid (PUFA)% varied between 58.89 and 66.71, 27.14 and 31.80, 24.58 and 29.03, and 2.23 and 2.99, respectively. As the log counts of lactococci were determined between 2.50 ± 0.1 and 3.03 ± 0.35, the log counts of lactobacilli were found between 3.60 ± 0.26 and 4.33 ± 0.41 at the 45th day. Total sensory point of the sample made with mixture culture in boiling at 85°C was the highest at the 15th day. The investigation results showed that L.helveticus (single or mixture) might be proposed as a starter culture alternated to yoghurt bacteria in Cokelek cheese made from cow milk.
Supercritical carbon dioxide extraction method was employed to extract the essential oil in Herba Moslae.The optimal conditions were determined by response surface methodology (RSM).Box-Behnken design was applied to evaluate the effects of three independent variables (temperature, pressure and extraction time) on the yield of the essential oil of Herba Moslae.The optimal conditions to obtain the highest yield of essential oil of Herba Moslae were determined as following values: 50°C of temperature, 20MPa of pressure and 77 min of dynamic extraction time. Under these optimal conditions, the experimental results agreed with the predicted values obtained by using analysis of variance. This indicates a high goodness of fit of the model used and the success of response surface methodology. Furthermore, the chemical compositions of essential oil in Herba Moslae were analyzed by gas chromatography mass spectrometer (GC-MS). The results showed that thymol (41.87%), carvacrol (26.91%) and p-Cymene (9.27%) are the major constituents in the essential oil of Herba Moslae.
The effects of the ripening period (1, 3, 7, 11, 13 days), nitrite level (45, 70, 120, 170, 195 mg kg-1) and heat treatment (30, 40, 60, 80, 90°C) on counts of total aerobic mesophilic bacteria, lactic acid bacteria (LAB) and Micrococcus-Staphylococcus in sucuk were investigated using a central composite rotatable design of response surface methodology. Counts of total aerobic mesophilic bacteria and lactic acid bacteria were increased and counts ofMicrococcus-Staphylococcus were significantly decreased during the ripening period (p<0.01). Counts of all bacteria were significantly decreased by the effects of heat treatment (p<0.01). Nitrite had a significant effect on total aerobic mesophilic bacteria.Enterobacteriaceae, moulds, and yeasts were observed only in the first days of the ripening period.
During the batch treatment of defatted rice bran by subcritical water, the temperature changes with time in order to reach the desired level. The bran was treated with subcritical water at different temperature rates from room temperature to 250°C to obtain extracts, and the properties of the extracts were examined. The extract yield was higher at higher temperature rates. UV-Visabsorption and high-performance liquid chromatography analyses indicated that the rate affected the substances contained in the extracts. However, the antioxidative ability of the extract versus the oxidation of linoleic acid only slightly depended on the rate. Therefore, a fast temperature increase to the desired level is favorable for high yield and short treatment time.
The objective of this study was to identify the mechanisms responsible for the characteristic taste and flavor of dried herring fillet(DHF, migaki-nishin in Japanese). Dialyzed water-soluble fractions (DWSF)obtained from herring fillet were dried for 4 days, mixed with fatty acids, and the reaction products were evaluated for their effects on sensory perception.To clarify the mechanisms of in situ chemical changes in DHF lipid, ESI-MS analysis was done using a phosphatidylcholine probe. Sensory evaluation revealed that addition of the reaction products of DWSF with docosahexaenoic acid to Japanese noodle soup significantly (P < 0.05) enhanced soup flavor characteristics, such as thickness, mouthfulness, and continuity, compared to the reaction products of DWSF with linoleic acid or capric acid. ESI-MS analyses showed that lyso-derivatives were the most abundant compounds in the lipid fraction of DHF. A small amount of lipid oxidation products and their reaction products were also observed in DHF. This study demonstrated that during the drying period, partial hydrolysis of lipids released free fatty acids. These free fatty acids, or their oxidation products, might react withamino acid-related compounds to generate the characteristic taste and flavor of DHF.
Fatty acid distribution of triacylglycerols and phospholipids isolated from five cultivars of adzuki beans (Vigna angularis) was investigated. Lipids were separated by TLC into eight subfractions. The lipid components comprised mainly phospholipids and triacylglycerols. The phospholipid components included phosphatidylcholine, phoshatidylinositol, and phosphatidylethanolamine. Comparison of these different cultivars showed, with a few exceptions, no significant differences in fatty acid distribution. Fatty acid distribution of triacylglycerols among the five cultivars was characterized as: unsaturated fatty acids predominantly concentrated at the sn-2 position and saturated fatty acids primarily occupying the sn-1 or sn-3 position in the lipids. These results should be useful information to both producers and consumers for manufacturing of traditional adzuki confectionaries(wagashi or an paste) in particularly Japan.
The content of insoluble bound phenolic acids in pearled barley was determined by an analytical system consisting of alkaline hydrolysis extraction, high-performance liquid chromatographic separation and electrochemical detection. Insoluble bound phenolic acids in five pearled cultivars and fifteen breeding lines of barley comprised ferulic acid (4.3-34.2mg/100 g dry matter), sinapic acid (0.025-0.445 mg/100 g), caffeic acid(0.002-0.016 mg/100 g). Soluble free polyphenols comprised procyanidins(12.2-80.3 mg/100 g), catechin (0.1-28.2 mg/100 g), and total pholyphenolcomprised 152.4-324.0 mg-gallic acid equivalents/100 g. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity for the barley samples ranged from 403 to 1501 μmol-Trolox equivalents/100 g whereas those of oxygen radical absorbance capacity (ORAC) ranged from 1050 to 3816 μmol-Trolox equivalents/100 g. High correlation (0.980, p<0.01) was found between the DPPH and ORAC assays. Total polyphenol contents positively correlated with the DPPH (0.875, p<0.01)and ORAC (0.881, p<0.01)assays. The correlation coefficient between insoluble bound phenolic acids and total polyphenol contents was higher than that between soluble free polyphenols and total poly-phenol contents. Taken together, the insoluble bound phenolic acids appear to greately contributed to the antioxidant activity in pearled barley.
The physicochemical and functional characteristics of the major coconut storage protein, 11S globulin or cocosin, were investigated.Cocosin was purified by a combination of salt extraction, selective precipitation, and gel filtration chromatography. The solubility of cocosin at different pH was higher at µ=0.5 than at µ=0.08. The 24 and 21 kDa basic polypeptides of cocosin were more resistant to chymotrypsin digestion than the 35 and 32 kDa acidic polypeptides. Cocosin emulsions were most stable at 0 M NaCl, followed by emulsions in 0.1 M and 0.4 M NaCl. The available SH groups were found to be 21.6 mole SH/mole cocosin. Cocosin was observed to be stable under various pasteurization conditions from 63°C, 30 min to 100°C, 10 sec. However, heating at 100°C for 10 min and longer degraded cocosin up to 60%. The thermal denaturation midpoint temperature, Tm, of the trimeric cocosin was 77.6°C while that of the hexameric form was 100.5°C.
Recently, we have identified the ubiquitin conjugate, protein phosphatase inhibitor 1 (I1), from postmortem muscles. Since I1 is one of the important regulators of glycogen metabolism, the effect of this conjugate (Ub-I1) present in postmortem muscle on glycolysis was investigated. Two sample groups were distinguishable: those not containing Ub-I1 (I, n=5)and those containing Ub-I1 (II, n=27). Due to the enormous variation in ultimate pH at 48 h postmortem, the latter group was subcategorized into a IIa group showing lower or normal pH and a IIb group showing higher or dark, firm, dry meat pH. Postmortem glycolysis occurred rapidly and vigorously among group I samples. The rate and extent of postmortem glycolysis was typical in group IIa samples while it was slower and weaker in group IIb samples although they had similar glycolytic potential. This discrepancy between sample groups IIa and IIb corresponded to the Ub-I1 abundance. Thus, the relative Ub-I1 abundance appears to correlate with postmortem glycolysis.
Lactic acid production from waste material has received much attention due to its sustainable utilization of biomass and the increasing demand for polylactic acid for use in biodegradable plastics. Canned pineapple syrup, a food processing waste, was utilized as a substrate for L-lactic acid production. To optimize the utilization of sucrose in pineapple syrup, in the presence of glucose and fructose, Lactobacillus paracasei NRIC 0765 was characterized and selected from 158 lactic acid bacteria strains. The selected strain possessed higher lactic acid productivity and sucrose hydrolysis enzyme activity in comparison with other Lb. paracasei strains examined when a sugar mixture was used as the carbon source. The highest lactic acid concentrations achieved were 19 and 93 g l-1 from 20 and 100 g l-1 total sugar in pineapple syrup, respectively, without a lag period for sucrose consumption. Using simple cultivation methods, we demonstrate that Lb. paracasei NRIC 0765 has a great capacity to produce L-lactic acid from sugar mixtures containing high sucrose concentrations.
The effects of simultaneous intake of miso (fermented soybean paste) soup on the glycemic index (GI) of cooked polished rice were examined in an intervention test on a larger number of subjects. Although the effects on GI varied among individuals, miso was found to decrease the GI of cooked polished rice to some degree. Particularly in the case of soybean-koji miso, the GI-decreased group was significantly larger than the GI-increased group (p<0.05). On the other hand, in subjects with efficient carbohydrate digestion, the GI of cooked polished rice was more likely to be lower with simultaneous intake of miso soup. Thus, miso apparently has an effect on carbohydrate (starch) digestion rather than absorption in the intestinal environment.
We characterized the antibacterial activity of Lactobacillus curvatus strain Y108 isolated from the traditional Japanese pickle Nozawana-zuke, and partially identified the antibacterial agent produced by the strain. The Y108 strain exhibited antibacterial activity against L. curvatus JCM1096, Listeria monocytogenes JCM7671, Staphylococcus aureus subsp. aureus JCM20624, and Serratia marcescens JCM20012.The antibacterial activity was abolished upon treatment with several proteases and lipase but not catalase, and it was moderately stable against heat treatment for 2 h at 100°C. The Y108 strain showed higher antibacterial activity when grown at 20°C than at 30°C, which is its optimal growth temperature. SDSPAGE analysis of the purified culture supernatant revealed the presence of two antibacterial peptide agents, F3-I and F3-II, with net molecular weights of 5.5 and 4.5 kDa, respectively. The N-terminal amino acid sequences of F3-I and F3-II were homologous to those of lactocin 705α and 705β, respectively. However, molecular masses and individual antibacterial activities of the two peptides were considerably different from those reported for lactocin 705.
We show that an extract of a new green tea cultivar Cha Chuukanbohon Nou6 (Nou6), which rich in anthocyanin, has an inhibitory effect on myosin regulatory light chain (MRLC) phosphorylation in rat aortic smooth muscle cell line A7r5. The inhibitory effect of Nou6 extract was abolished when the extract was treated with polyvinylpyrrolidone which traps polyphenols.However, none of the major tea constituents tested had an inhibitory effect.In addition, we found that Nou6 extract had a strong effect on reducing the phosphorylation of myosin phosphatase targeting subunit 1 at Thr696. These results suggest that Nou6 extract inhibits MRLC phosphorylation induced by thrombin through activating myosin light chain phosphatase, and polyphenols in the tea extract may contribute to this effect.
Osmotic stress hampers the growth of Saccharomyces cerevisiae, and this effect is mediated by oxidative stress. A simple test for the biological evaluation of antioxidants was developed on the basis of recovery of growth delay of Cu, Zn-superoxide dismutase-lacking yeast (SOD1Δ)under hyperosmosis. The SOD1Δstrain suffered from growth inhibition in a medium containing 1.7 M sorbitol. Protein oxidation in SOD1Δ cells was greatly increased by exposure to a hypertonic medium, indicating the accumulation of reactive oxygen species followed by oxidation of cellular materials. The hyperosmosis-induced growth arrest of SOD1Δ was abolished by the addition of L-ascorbic acid to the medium; the antioxidant effect depended on the concentration, ranging from 1 to 10 mM.Cysteine, N-acetyl-cysteine, and glutathione were also able to restore the growth of SOD1Δ cells. High concentrations of these thiol compounds proved less effective, probably due to adverse effects of an excess of these antioxidants. No growth restoration was seen for typical polyphenol antioxidants, including curcumin, quercetin and catechin.