Cooking method Dotaz Zobrazit nápovědu
Cooking can positively affect meat tenderness, on the other hand, the heat treatment also causes weight loss. The resulting tenderness of cooked meat is influenced by the background toughness of fresh meat, by the post mortem ageing process and by the method of cooking. In the case of heat treatment, the temperature and duration of action play a key role. In this respect, the meat tenderness depends on the type of appliance used for cooking. The cooking loss of meat during heat treatment is caused by contraction of muscle fibres and intramuscular connective tissue, the intensity of which also depends on the temperature and device used. The extent of this contraction increases with increasing temperature. Cooking of meat is considered the most effective way of eliminating microorganisms causing food-borne diseases. The recommended combination of temperature and time of 70 °C for 2 min reduces the number of Listeria monocytogenes bacteria by more than 6 log. This temperature is not, however, always attained with the use of many meat cooking methods, such as grilling or frying. This presents the risk of survival of food-borne agents. The latest knowledge indicates that, in the case of cross contamination, the population of food-borne agents is of the order of 1–2 log CFU/cm2 or g. If they do not multiply as a result of a higher environmental temperature, the population of pathogenic bacteria present is then reliably eliminated during adequate cooking, either entirely or to an amount that does not suffice to induce illness.
In this study, a novel harvesting emulsion (HEM) consisting of cooking oil in an aqueous solution of cetyltrimethylammonium bromide (CTAB) was tested for the harvesting of a technologically important microalga, Chlorella vulgaris. The influence of HEM dose, biomass and bovine serum albumin (BSA) (model interferer compound) on harvesting efficiency (E) were studied. The HEM E was over 90% at pH 10 (0.33% (v/v) cooking oil, 6.7 mg/L of CTAB) and 12 (0.13% (v/v) cooking oil, 2.7 mg/L of CTAB). Harvesting efficiencies at pH 4 and 7 were < 73.5% due to the absence of precipitate formation. Bovine serum albumin (10 mg/L) increased the HEM dose necessary to achieve E ˃ 90% by 1.2 (pH 10), and 3 fold (pH 12). By manipulating the dose of HEM and pH, the method of harvesting (flocculation/sedimentation or flotation) was adjustable depending on the technological requirements.
- MeSH
- biomasa MeSH
- Chlorella vulgaris * MeSH
- flokulace MeSH
- mikrořasy * MeSH
- povrchově aktivní látky MeSH
- vaření MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this work was to develop a soap-based method for the isolation of poly(3-hydroxybutyrate) from bacterial biomass. The method consisted of adding soap derived from waste cooking oil to a concentrated (25%) biomass suspension, heating and centrifugal separation. Purity above 95% could be achieved with soap:cell dry mass ratios at least 0.125 g/g, making the method comparable to other surfactant-based protocols. Molecular weights Mw of products from all experiments were between 350 and 450 kDa, being high enough for future material applications. Addition of hydrochloric acid to the wastewater led to the precipitation of soap and part of non-P3HB cell mass. The resulting precipitate was utilized as a carbon source in biomass production and increased substrate-to-P3HB conversion.
- MeSH
- biomasa MeSH
- bioreaktory * MeSH
- hydroxybutyráty MeSH
- kyselina 3-hydroxymáselná MeSH
- mýdla * MeSH
- polyestery MeSH
- vaření MeSH
- Publikační typ
- časopisecké články MeSH
Putrescine (PUT), spermidine (SPD) and spermine (SPM) concentrations using a UPLC method, in chilled mutton, lamb and livers 24 h after slaughter were determined. PUT concentrations were quantifiable only in some samples. Mean SPD concentrations were 4-6, 13.5 and 16.8 mg kg-1 in the meats, sheep and lamb livers, respectively. The respective SPM concentrations were 17-25, 128 and 79 mg kg-1. SPD and SPM losses of about one fifth and half of the initial level, respectively, were apparent in mutton loins stored at -18°C for 6 months. Significant losses of SPD and SPM were found in mutton loins stored aerobically, vacuum-packaged or in a modified atmosphere at +2°C. Boiling and stewing of mutton legs caused SPD and SPM losses of about 40% and roasting of about 60% of the initial content.
Electrospray ionization generates trimeric diastereoisomeric clusters as the first important step in chiral analysis by mass spectrometry using the Cooks' kinetic method. Cu2+ and L-tryptophan were used as a central metal and as a chiral reference ligand, respectively. The comparison of electrospray and nanoelectrospray showed that although the electrospray system was generally more robust, the application of nanoelectrospray was essential for performing successful analysis in some cases, especially for real samples. Basically, no significant differences between the ion sources were observed for model samples of analytes (isoleucine, ephedrine, phenylalanine) without interfering matrix. On the other hand, model samples containing sodium chloride and a buffer containing a real sample (drug formulation Mucoseptonex E in which D-ephedrine is the active substance) could not be analyzed using ESI, whereas nano-ESI gave satisfactory results. An explanation is based on the differences of ionization processes occurring in the compared sources.
BACKGROUND: Total phenolic content, phenolic profile and antioxidant activity were determined in free and bound phenolic fractions of thermally treated brown and white teff grains. RESULTS: Phenolic content in raw brown and white teff (1540 and 992 mg gallic acid equivalent kg-1 ) as well as antioxidant activity (6.3 and 5.5 mmol trolox equivalent kg-1 ) were higher in free phenolic fractions. The most significant decrease in total phenolics was observed after application of the sous-vide method (35% for brown teff and 11% for white teff). Main free phenolics of heat-treated teff were ferulic, protocatechuic, p-coumaric and ellagic acids, rutin and epigallocatechin. Main bound phenolics were ferulic, gallic, sinapic and ellagic acids, catechin and epigallocatechin. The detrimental effect on free and bound quercetin and bound cinnamic acid concentrations was also examined during heat treatment. Thermally treated brown teff showed a high level of in vitro organic matter digestibility if water cooking and rice cooker (both 99.5%) and sous-vide (96.5%) methods were applied. CONCLUSION: The sous-vide method may be recommended as the most suitable hydrothermal treatment for grains of teff when compared with water cooking and rice cooker methods. © 2017 Society of Chemical Industry.
- MeSH
- antioxidancia chemie metabolismus MeSH
- biologické modely MeSH
- Eragrostis chemie MeSH
- fenoly chemie metabolismus MeSH
- lidé MeSH
- rostlinné extrakty chemie metabolismus MeSH
- trávení MeSH
- vaření MeSH
- vysoká teplota MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
We have proposed the method of transvaginal Voluntary Surgical Contraception, conducted in conjunction with surgical treatment of descent and prolapse of the vaginal walls. Were studied the early and late results of the surgery in 50 women to which during the surgical treatment of genital prolapse simultaneously was carries out transvaginal occlusion of the fallopian tubes. Control groups consisted of 30 women to which in the first step before surgical correction of pelvic organ prolapse have been performed minilaparotomy and DCA. Our method consists in penetrating into the abdominal cavity through the front vaginal vault, to downgrade the fallopian tubes with a hook Ramatibodi and tubal sterilization method Pomeroy. Intra - and postoperative complications were not recognized. In the long-term period after surgery - the effectiveness of the method was 100%. Marked tendency to improve the quality of sexual life tells about the positive impact of removing the genital prolapse with simultaneous DCA on the quality of life of women.
