scholarly journals Fermentation efficiency of high-gravity rye mashes using pressureless starch liberation methods

2017 ◽  
Vol 35 (No. 3) ◽  
pp. 267-273 ◽  
Author(s):  
Ewelina Strąk ◽  
Maria Balcerek ◽  
Urszula Dziekońska- Kubczak

The efficiency of ethanol production during simultaneous saccharification and fermentation (SSF) of gelatinised starch or in its native form, in high-gravity rye mashes (approx. 21% and approx. 25% dry matter) prepared by pressureless methods of starch release were compared. The obtained fermentation efficiency expressed in % of the theoretical yield was 72.98 ± 1.46% for gelatinised starch and 84.27 ± 1.68% for native starch in the mashes with 21% dry matter, while the use of mashes with 25% dry matter content resulted in 71.22 ± 1.42% and 77.36 ± 1.54% of the theoretical yield, respectively. However, the presence of residual dextrins (1.99 ± 0.82 to 3.04 ± 0.39 g/100 ml) in the fermented mashes suggests the need of further research on the improvement of the process.

2020 ◽  
Vol 13 (6) ◽  
pp. 923-936 ◽  
Author(s):  
Ewelina Strąk-Graczyk ◽  
Maria Balcerek

Abstract The rising population and increasing demand for food place added pressure on the agricultural sector to maintain high process efficiency while implementing environmentally friendly methods. In this study, we investigate the effect of pre-hydrolysis of native rye starch and its influence on the yield of ethanol obtained by simultaneous saccharification and fermentation (SSF) from high gravity rye mashes with 25% and 28% w w−1 dry matter content. Fermentation was carried out in a 3-day system at a temperature of 35 ± 1 °C using the dry distillery yeast Ethanol Red (Saccharomyces cerevisiae). The characteristics of the tested raw material and changes in the native rye starch during enzymatic hydrolysis were analyzed using a scanning electron microscope (SEM). The SEM images revealed characteristic changes on the surface of the starch, which was found to have a layered structure, as well as interesting behavior by the yeast during SSF when the glucose concentration in the environment was lowered. Both in the mashes with 25% and 28% w w−1 dry matter, starch pre-hydrolysis did not significantly increase either the initial amounts of sugars available to the yeast or the fermentation efficiency and ethanol yield in comparison to the mashes without this pre-treatment.


2010 ◽  
Vol 26 (3-4) ◽  
pp. 167-177 ◽  
Author(s):  
M. Bojanic-Rasovic ◽  
S. Mirecki ◽  
N. Nikolic ◽  
R. Rasovic

The aim of paper was to examine the impact of the milk quality on yield of semi-hard naturally dried cheese, produced in cheese plant factory ZZ 'Cijevna' in Podgorica. Tests were conducted on 6 samples of bulk milk of cows and 6 productive batch of cheese. Chemical tests of the bulk milk have been done on the device MilcoScan 4000, and the determination content dry matter of whey and dry matter of cheese on the device MilcoScan FT 120. Theoretical yield of cheese was determined in two ways: 1) based on the content of fat and protein content in milk and 2) based on dry matter content of milk, dry matter of whey and dry matter of cheese. Actual yield of cheese is determined on the base of the total amount of cheese obtained after pressing and the amount of wasted milk. The average value for the fat content in the examined milk amounted to 3.79%, protein 3.24%, 4.26% lactose and dry matter content without fat 8.24%. The average value for the theoretical cheese yield by first method was 10.65% and by second method 9,30%. The average of actual cheese yield amounted to 11.26%. We found a very high positive correlation between content of fat in milk and actual cheese yield (0.929032) and mean positive correlation between content of protein in milk and actual cheese yield (0.613141), content of lactose in milk and actual cheese yield (0.651317) and between dry matter content in milk and actual cheese yield (0.651956).


Author(s):  
Nguyễn Đình Thi ◽  
Thái Thị Hồng Mỹ ◽  
Lê Thị Hương Xuân

Nghiên cứu ảnh hưởng của các nồng độ Na2SO3 (0, 100, 300, 500 ppm) đến 03 giống sắn KM 94, KM 21-12 và KM 444 trong năm 2019 tại vùng sinh thái gò đồi thị xã Hương Trà, tỉnh Thừa Thiên Huế nhằm mục đích xác định ảnh hưởng và nồng độ Na2SO3 phù hợp cho cây sắn. Kết quả đạt được là: 1) Phun Na2SO3 ở các nồng độ thí nghiệm đã tăng sinh trưởng thân - lá - củ, năng suất, chất lượng củ và hiệu quả kinh tế của 03 giống sắn thí nghiệm. 2) Tại nồng độ phun Na2SO3 từ 300 đến 500 ppm, so với đối chứng giống KM 94 tăng năng suất thực thu 19,5 - 20,2%, tỷ lệ sắn lát đạt 40,9 - 41,1%, hàm lượng tinh bột đạt 29,3 - 30,2% và năng suất ethanol tăng 23,6 - 26,6%; Giống KM 21-12 tăng năng suất thực thu 15,1 - 18,6%, tỷ lệ sắn lát đạt 40,5 - 41,0%, hàm lượng tinh bột đạt 29,7 - 29,8% và năng suất ethanol tăng 21,6 - 25,8%; Giống KM 444 tăng năng suất thực thu 18,4 - 19,9%, tỷ lệ sắn lát đạt 40,6 - 40,8%, hàm lượng tinh bột đạt 30,3 - 30,9% và năng suất ethanol tăng 24,9 - 25,7%. ABSTRACT The study on the effects of Na2SO3 concentrations (0, 100, 300, 500 ppm) on 03 cassava varieties (KM 94, KM 21-12 and KM444) was conducted in 2019 in hilly ecological area of Huong Tra town, Thua Thien Hue province to determine the effect and suitable concentration of Na2SO3 for cassava. The results showed that: 1) Spraying Na2SO3 at a rate of 640 liters/ha with experimental concentrations increased stem - leaf - root growth, yield and quality of roots and economic efficiency of all of 03 cassava varieties. 2) Spraying Na2SO3 at concentrations from 300 to 500 ppm, compared with the control, KM 94 increased root yield of 19.5 - 20.2%, dry matter content reached 40.9 - 41.1%, starch content reached 29.3 - 30.2% and ethanol production increased by 23.6 - 26.6%; KM 21 - 12 increased root yield of 15.1 - 18.6%, dry matter content reached 40.5 - 41.0%, starch content reached 29.7 - 29.8% and ethanol production increased by 21.6 - 25.8%; KM 444 increased root yield of 18.4 - 19.9%, dry matter content reached 40.6 - 40.8%, starch content reached 30.3 - 30.9% and ethanol production increased by 24.9 - 25.7%.  


2009 ◽  
Vol 15 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Dusanka Pejin ◽  
Ljiljana Mojovic ◽  
Olgica Grujic ◽  
Jelena Pejin ◽  
Marica Rakin

In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield) was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin stillage, the bioethanol yield increased and was above 100 %. Higher bioethanol yield than 100 % can be explained by the fact that the thin stillage contains carbohydrates, amino acids and yeast cells degradation products. The bioethanol yield increased with the increased number of thin stillage recirculation cycles. Dry matter content in fermenting slurry increased with the increased thin stillage quantity and the number of the thin stillage recirculation cycles (8.04 % for the first and 9.40 % for the sixth cycle). Dry matter content in thin stillage increased with the increased thin stillage quantity and the number of thin stillage recirculation cycles. Based on the obtained results it can be concluded that thin stillage recirculation increased the bioethanol yield. The highest bioethanol yields were obtained with recirculation of 10% thin stillage.


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