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51.
52.
The aim of this work was to investigate cold-pressed rosemary oil (RO) for its lipid classes, subclasses, fatty acid composition, tocochromanols and total phenolics amount. Antiradical activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH?) and galvinoxyl radicals, antioxidant activity, as measured by the Rancimat test, as well as antimicrobial activity against food-borne bacteria, and dermatophytic fungi of RO were evaluated. In RO, the amount of neutral lipids was highest (ca. 86%), followed by phospholipids (0.92%) and glycolipids (0.88%). The percentages of monounsaturated, polyunsaturated, and saturated fatty acids were 41.7, 42.3, and 15.8%, respectively. Linoleic acid (41.7%) and oleic acid (41.2%) were the major fatty acids while linolenic acid accounted for 1.3% of total fatty acids. The following tocochromanols were detected: α-, β-, γ- and δ-tocopherols, which accounted for 291, 22, 1145, and 41 mg/100 g oil, respectively, as well as α-, β-, γ- and δ-tocotrienols, which accounted for 18, 12, 29, and 158 mg/100 g oil, respectively. RO also contained high levels of phenolic compounds (7.2 mg GAE/g). After 60 min of reaction with free radicals, 67% of DPPH? and 55% of galvinoxyl radicals were quenched by RO. Rancimat test showed that blending RO with sunflower oil increased the induction period (IP) for blends. The IP of the RO: sunflower oil blend (1:9, v/v) was 390 min, and RO: sunflower oil blend (2:8, v/v) was longer (540 min). RO exhibited high antimicrobial potential against food-borne pathogenic bacteria (E. coli, S. enteritidis, and L. monocytogenes) and high antifungal potential against dermatophyte fungi (T. mentagrophytes, and T. rubrum). RO had unique high level of γ-tocopherol, which is a scavenger of reactive nitrogen species making it a promising material in the food, cosmetic and pharmaceutical applications.  相似文献   
53.
Protein modification via enzymatic cross-linking is an attractive way for altering food structure so as to create products with increased quality and nutritional value. In this study, enzymatic cross-linking of β-casein was performed by tyrosinase activity, from melanin-free ink from Sepia officinalis, which was monitored by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) techniques. The melanin-free ink contains a strong tyrosinase activity with pH 7 and 58?°C as optima of pH and temperature, respectively. Such activity is stimulated by ferrous ions and strongly inhibited by Mn2+, EDTA, H2O2, arbutin, and p-coumaric acid. We also show that 2 Mercapto-ethanol (14?mM) quickly and completely inactivated sepia tyrosinase. The melanin-free ink exhibits a major protein on SDS–PAGE with an N-terminal sequence matching perfectly with an internal sequence of the sepia peroxidase. The zymogram confirmed the inactive state of this truncated protein and the presence of an active tyrosinase enzyme. Interestingly, this activity was able to cross-link the β-casein protein. The tyrosinase implication in reticulation was demonstrated by the addition of its inhibitors, with 2-mercaptoethanol being the most effective, followed by arbutin, p-coumaric acid, and hydrogen peroxide.  相似文献   
54.
This study investigated the potential of peanut skin extract (PSE) as inhibitor of lipid oxidation in cooked and raw ground beef (GB) and as antimicrobial agent in raw GB. Results show that addition of PSE to raw GB before cooking significantly inhibited the formation of peroxides and TBARS in cooked GB during the refrigerated storage. PSE at concentration ≥0.06% was as effective as BHA/BHT at 0.02% in inhibiting lipid oxidation. PSE also inhibited the oxidation of meat pigments thereby preserving the fresh redness of treated meat when used at 0.02–0.10%. Microplate assay showed complete inhibition of test bacteria (Bacillus subtilis, Salmonella typhimurium, Staphylococcus aureus, Streptococcus faecalis and Escherichia coli) in the presence of PSE at 0.4% or higher. However, the antimicrobial effect of PSE in GB was less potent. Hence, PSE can primarily serve the dual purposes of preserving the colour of raw GB and preventing lipid oxidation in cooked products.  相似文献   
55.
Mangifera pajang (family: Anacardiaceae; local name: bambangan) and Artocarpus odoratissimus (familiy: Moraceae; local name: tarap) are popular edible fruits in Sabah, Malaysia. The flesh, kernel and peel from M. pajang; seed and flesh from A. odoratissimus were analysed for total antioxidant activity, total polyphenol, total flavonoid and total anthocyanins contents. M. pajang kernel extract displayed the highest free radical scavenging and ferric reducing activities. Total phenolic content of the samples were in the range of 5.96–103.3 mg gallic acid equivalent/g. M. pajang kernel and M. pajang flesh contained the highest and lowest total flavonoid content with the values of 10.98 and 0.07 mg rutin equivalent/g, respectively. The antioxidant activities of extracts were significantly correlated with the total phenolic and flavonoid content (but not the anthocyanins content). The phytochemicals and antioxidant properties of M. pajang and A. odoratissimus, especially their by-products (kernel/seed), indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidant-rich nutraceuticals.  相似文献   
56.
Determination of biogenic amines in selected Malaysian food   总被引:3,自引:0,他引:3  
The biogenic amines tryptamine (TRP), putrescine (PUT), histamine (HIS), tyramine (TYR) and spermidine (SPD) were determined in 62 selected food items commonly consumed in Malaysia. This include the local appetisers “budu” and “cincalok”, canned fish, salt-cured fish, meat products, fruit juice, canned vegetables/fruits and soy bean products. After the aqueous extraction, the samples were derivatised with dansyl chloride before analysing using reversed phase HPLC with UV detection. Mean levels of TRP, PUT, HIS, TYR and SPD in eight budu samples were 82.7, 38.1, 187.7, 174.7 and 5.1 mg kg−1, respectively. The main biogenic amines found in cincalok were PUT, HIS and TYR where the mean values were 330.7, 126.1 and 448.8 mg kg−1, respectively. With the exception of “pekasam” and “belacan”, significantly lower levels of biogenic amines were found in canned fish and salt-cured fish samples. Non detectable or low levels of biogenic amines were found in meat, fruit juice and canned vegetables/fruit samples.  相似文献   
57.
Study of the rat embryo surface under the scanning electron microscope shows the superficial structure of the pellucid membrane as a perforated network cover which does not change throughout the preimplantation period (1 to 41/2 days). Dissolution of the pellucid membrane by brief ATP treatment reveals a zygotic surface which changes from day to day. The number and length of microvilli increase with development. At the early blastula stage there is a great heterogeneity of microvilli of different size and shape as well as large membranous ruffles mainly located at one pole of the embryo. The significance of these structures may relate to the changing metabolic requirements of the developing embryo and to the invasive properties of the trophoblast.  相似文献   
58.
Fingerprints were obtained from 100 patients with mitral valve prolapse and compared with those of 100 control subjects matched for sex and race. Arches were found in 16.8 percent of all digital patterns in patients with mitral valve prolapse but in only 2.5 percent of all digits in the control group. Whereas no patient in the control group had four or more arches, 19 percent of patients with mitral valve prolapse had this finding. In addition, arches were found on 16 and 9 percent, respectively, of digits IV and V in patients with mitral valve prolapse but were not found on these digits in the control group. The finding of four or more arches or arches on digits IV or V may be important supportive evidence of mitral valve prolapse when evaluating patients with atypical chest pain and palpitations. Antenatal factors may be involved in the pathogenesis of mitral valve prolapse since it is possible that a genetic or environmental factor that interferes with the development of the mitral valve may also influence epidermal ridge patterns.  相似文献   
59.
With the new method the fecal flora of 13 clinically healthy dogs aged 3 to 42 months was analysed qualitatively and quantitatively. It was characterized by that bacteroidaceae constituted the most prodominant flora, catenabacteria, streptococci, peptostreptococci, lactobacilli and bifidobacteria were the next most numerous, enterobacteria consisted the accompanying flora. The numbers of Clostridium perfringens were remarkably fluctuated and seem to be influenced by the composition of the food ingested by the host. The total cultivable counts averaged log 10.8 +/- 0.2/g. The composition of the Lactobacillus flora and Bifidobacterium flora in the feces of 34 dogs from 3 different age groups was analysed. In the feces of all age groups L. acidophilus, L. salivarius and L. fermenti with 9 different types were found. Within the lactobacilli L. acidophilus type VI c, L. salivarius type VI a and L. fermenti type IV b were most frequently found. L. acidophilus types VI c and XI, L. salivarius types VI a and VI b could not be placed in any established types of each species, and were described as new types. Bifidobacteria were regularly found in large numbers in the feces of dogs aged 2 to 24 months. B. adolescentis and B. pseudolongum consisted the main Bifidobacterium flora.  相似文献   
60.
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