Technologies of fibrous semi-finished products for various purposes from miscanthus

В ходе исследовательской работы проанализированы способы получения целлюлозы из недревесного растительного сырья. Отработана технология получения целлюлозы высокого выхода сульфатным способом из мискантуса, пригодной для использования в композиции компонентов тарного картона. Условия получения целлюлозы высокого выхода: расход активной щелочи – 7%, температура – 150 °С, продолжительность – 30 мин, гидромодуль варки – 5, продолжительность горячего размола – 5 мин. Отработана технология получения химико-термомеханической массы из сечки. Условия получения: расход активной щелочи – 3%, продолжительность пропитки при 90 °С – 10 мин, продолжительность обработки при 120 °С – 10 мин, гидромодуль – 5. Отработан технологический режим отбелки химико-термомеханической массы из мискантуса по укороченной схеме Х – ЩП1 – ЩП2 с расходом Н2О2 60 кг/т, белизна образца составила 55% ISO. Отработана технология получения нейтрально-сульфитной полуцеллюлозы из мискантуса, пригодной для использования в композиции компонентов тарного картона. Условия получения нейтрально-сульфитной полуцеллюлозы: расход активной щелочи – 20%, температура – 175 °С, продолжительность – 50 мин, гидромодуль варки – 7, продолжительность горячего размола 5 мин. В соответствии с полученными результатами можно сделать вывод о том, что мискантус может быть использован для получения аналога лиственной сульфатной целлюлозы для применения в композиции различных видов бумаг. In the course of the research work, methods for obtaining cellulose from non-wood plant raw materials were analyzed. The technology of obtaining high yield cellulose by sulphate method from miscanthus, suitable for use in the composition of container cardboard components, has been developed. Conditions for obtaining high yield cellulose: active alkali consumption –7%, temperature-150 °C, duration – 30 minutes, cooking hydromodule – 5, duration of hot grinding – 5 minutes. The technology of obtaining a chemical-thermomechanical mass from a cross-section has been worked out. Production conditions: active alkali consumption – 3%, impregnation duration at 90 °C – 10 min, processing duration at 120 °C – 10 min, hydromodule – 5. The technological mode of bleaching the chemical-thermomechanical mass from miscanthus according to the shortened scheme Q – P1 – P2 with a consumption of H2O2 of 60 kg/t, the sample whiteness was 55% ISO. The technology of obtaining neutral-sulfite semi-cellulose from miscanthus, suitable for use in the composition of container cardboard components, has been developed. Conditions for producing neutral-sulfite semicellulose: active alkali consumption – 20%, temperature – 175 °C, duration – 50 minutes, cooking hydromodule – 7, duration of hot grinding – 5 minutes. In accordance with the results obtained, it can be concluded that miscanthus can be used to obtain an analog of leafy sulphate cellulose for use in the composition of various types of papers.

The influence of investigated factors on viscosity of stirred yogurt

Skim milk was reconstituted to obtain milk with 8.44% DM, which was standardized with demineralized whey powder (DWP) to obtain milk sample A (9.71% DM) and milk sample B (10.75% DM). Milk samples were heat treated at 85?C/20 min and 90?C/10 min, respectively. Untreated milk was used as control. Milk samples were inoculated with 2.5% of commercial yogurt culture (containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in the ratio 1:1) at 43?C. Samples were incubated until pH 4.6 was reached. Samples were immediately cooled to 4?C and held at that temperature until analyses. Samples of acid casein gels were stirred after 1, 7 and 14 days of storage. Measurements of viscosity were done with Brookfield DV-E Viscometer. Spindle No 3 at 30 rpm was used for all samples. Duration of fermentation decreased when DWP was used for standardization of milk dry matter content. Yogurt samples produced from milk heat treated at 85?C/20 min, obtained by stirring of gel 1 day after production had a higher viscosity than sample produced from milk heat treated at 90?C/10 min. On the other hand, samples produced from milk heat treated at 90?C/10 min had a greater viscosity after 7 and 14 days of storage, which indicates a greater hydrophilic properties and a more pronounced swelling of casein micelles.

The influence of GDL concentration on milk pH change during acid coagulation

Skim milk powder was reconstituted to obtain milk A (with 8.01% TS). Milk A was standardized with 3% of skim milk powder and 3% of demineralized whey powder (DWP), respectively, to obtain milk B (with 11.15% TS) and milk C (with 11.10% TS). Milk samples were heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min, respectively. Untreated milk was used as control. Acidification was carried out at 25?C, 35?C and 45?C during 240 min with GDL (glucono-d-lactone), namely with the amount of 0.5%, 0.75%, 1.0%, 1.25% 1.5%, 1.75%, 2.0% and 3.0% of GDL, respectively. The results showed that all investigated factors, explicitly GDL concentration, acidification temperature and applied heat treatment of milk as well as added DWP influence the change of pH during acidification. Milk samples standardized with DWP had smaller buffer capacity and faster change of pH than samples standardized with skim milk powder. Only at acidification temperature of 25?C, added DWP did not influence the change of milk buffer capacity regardless of the change of casein:whey protein ratio. Under this acidification condition, both milk samples standardized with skim milk powder and DWP had similar final pH values.

The influence of applied heat treatments on whey protein denaturation

Reconstituted skim milk with 8.01% DM was standardized with 3% skim milk powder and with 3% demineralized whey powder (DWP), respectively. Gained milk samples are named as 8%, 11% and 8%+3%DWP. All samples were heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min, respectively. Untreated milk was used as control. Milk samples were coagulated by glucono-d-lactone (GDL) at the temperature of 45?C until pH 4.60 was reached. Milk nitrogen matter content decreased during heat treatments, but linear relationship between applied heat treatments and nitrogen matter decreasing was not found. Nitrogen matter content of sera gained from both untreated and heat treated milk increased with the increase of milk dry matter content and with the addition of DWP. The higher temperature of applied heat treatment, the smaller sera nitrogen matter content. Nitrogen matter content in sera obtained from untreated milk were 64.90 mg%, 96.80 mg% and 117.3 mg% for milk 8%, 11% and 8%+3.0% DWP, respectively. Sera samples obtained from milk 8% heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min had 38.70 mg% 38.30 mg% and 37.20 mg% of nitrogen matter, respectively. Sera samples obtained from milk 11% heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min had 55.90 mg%, 52.80 mg% and 51.30 mg% of nitrogen matter, respectively. Sera samples obtained from milk 8% heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min had 69.50 mg%, 66.20 mg% and 66.00 mg% of nitrogen matter respectively. Distribution of nitrogen matter from untreated milk to milk sera were 12.01%, 11.14% and 17.69% for milk 8%, 11% and 8%+3.0% DWP respectively. Distribution of nitrogen matter from milk 8% heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min to sera samples were 6.99%, 6.72% and 6.59%, respectively. Distribution of nitrogen matter from milk 11% heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min to sera samples, were 6.02%, 5.32% and 5.21%, respectively. Distribution of nitrogen matter from milk 8%+3%DWP heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min to sera samples were 9.64%, 8.66% and 8.67%, respectively. Whey protein denaturation increased with increasing of the temperature of the applied heat treatment. Denaturation was the most significant for milk sample 11%.

The influence of dry matter, applied heat treatment and storage period on the viscosity of stirred yogurt

Skim milk powder reconstituted to 8.44% TS, 9.65% TS and 10.84% TS respectively was used for investigation. Untreated milk and milk heat treated at 85?C/20 min and 90?C/10 min, respectively, were used for the investigation. Milk was inoculated with 2.5% of yogurt culture (containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in the ratio 1:1) at 43?C. Samples were incubated until pH 4.6 was reached. Samples were immediately cooled to 4?C and held at that temperature during 14 days. Acid casein gel was stirred after 1, 7 and 14 days of storage. Measurements were done at 30 rpm during 2 min, at 20?C. According to the investigation, it could be concluded that both applied heat treatment and dry matter content influence viscosity of stirred yogurt. Viscosity increases when dry matter content increases. The smallest viscosity had yogurt produced from untreated milk with 8.44% TS, while samples produced from milk with 10.84% TS had the highest viscosity. Applied heat treatments had significant influence on viscosity of yogurt gained by stirring of acid casein gels after 7 and 14 days of storage. Stirred yogurt produced from milk heat treated at 90?C/10 min had a higher viscosity than samples produced from milk heat treated at 85?C/20 min. Storage period influenced average viscosity of stirred yogurt. Samples of stirred yogurt produced from milk with 8.44% TS showed a decrease of average viscosity during storage regardless of the applied heat treatment of milk. The highest average viscosity had samples produced from milk with 10.84% TS.

Viscosity of set-style yogurt as influenced by heat treatment of milk and added demineralized whey powder

Skim milk powder was reconstituted to obtain milk A (with 8.44% TS). Milk sample A was standardized with different amounts of demineralized whey powder (DWP) to obtain milk B (with 9.71% TS) and milk C (with 10.75% TS). Milk samples were heat treated at 85?C/20 min and 90?C/10 min, respectively. Untreated milk was used as control. Milk samples were inoculated with 2.5% of commercial yogurt culture (containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in the ratio 1:1) at 43?C. Samples were incubated until pH 4.6 was reached. Samples were immediately cooled to 4?C and held at that temperature until analyses. Measurements of viscosity were done with Brookfield DV-E Viscometer. Spindle No 3 at 20 rpm was used for all samples. After 1 day of storage, set-style yogurt samples produced from untreated milk had the highest, while samples produced from milk heat treated at 90?C/10 min the smallest initial viscosity, regadless of the dry matter content and composition. Average viscosity of set-style yogurts decreased with intensifying temperature of applied heat-treatment. During storage, set-style yogurt samples produced from milk heat treated at 90?C/10 min had the least pronounced decrease of viscosity during shearing. After 14 days of storage, set-style yogurt samples produced from milk standardized with demineralized whey powder had higher viscosity than samples produced from basis milk.

Degranulation enhances release of a stable contractile factor from rabbit polymorphonuclear leukocytes

We investigated the release of a stable contractile factor(s) from rabbit isolated polymorphonuclear leukocytes (PMNs; 108cells/ml) incubated in Tyrode buffer at 37°C. PMNs were untreated, stimulated with N-formylmethionyl-leucyl-phenylalanine (FMLP; 0.1 μM), or degranulated with cytochalasin B (1 μM) in combination with FMLP (0.1 μM). Products from unstimulated PMNs incubated for 60 min caused significantly greater contraction of rabbit isolated aorta (0.56 ± 0.12 g, n = 8) than did products released from PMNs during a 5-min incubation (0.32 ± 0.07 g, n = 11, P < 0.05). Stimulation alone did not affect contractile factor release; however, products released from degranulated PMNs caused significantly greater aortic contraction (0.48 ± 0.08 g, n = 5) than products from nondegranulated PMNs (0.24 ± 0.04 g, n = 5, P < 0.05) after a 5-min incubation. The contractile activity of PMN-derived products was virtually abolished by heat (90°C, 10 min) or protease (trypsin; 166 U/ml, 5 h) treatment. These findings suggest a PMN-derived protein vasoconstrictor(s) is spontaneously released at a slow rate in vitro and that degranulation can enhance this rate of release. Because PMN degranulation in vivo is associated with inflammation, these results support suggestions that PMN-derived contractile factors may contribute to the impaired blood flow observed during postischemic reperfusion.