scholarly journals Influence of selected factors on the viscosity of set style yogurt and acid casein gel at constant speed of spindle rotation

2004 ◽  
Vol 49 (2) ◽  
pp. 233-250 ◽  
Author(s):  
Safet Fetahagic ◽  
Jelena Denin-Djurdjevic ◽  
Snezana Jovanovic ◽  
Ognjen Macej
Keyword(s):  
Linear Relationship ◽  
Dry Matter ◽  
Heat Treatments ◽  
Matter Content ◽  
Constant Speed ◽  
Dry Matter Content ◽  
Milk Samples ◽  
Heat Treated ◽  
Spindle Rotation

The influence of milk dry matter (DM) content (8.20%, 9.27% and 10.28%) and applied heat treatments (untreated milk and milk heat-treated at 90oC/10?) on the viscosity of set-style yogurt and acid casein gel gained by acidification with GDL (glucono-d-lactone) has been investigated. Viscosity was measured during the time of 3 minutes at constant speed of spindle rotation of 20 rpm. The results have shown that yogurt samples produced from untreated milk had higher viscosity values than samples produced from heat-treated milk. An increase of dry matter content influenced the increase of viscosity of yogurt samples produced from both untreated milk and heat-treated milk. Samples with 10.28% DM had the highest viscosity values. An increase of DM content in samples of acid casein gel produced by acidification with GDL had an opposite influence. The samples with smallest DM content had the highest viscosity values. There is no linear relationship between the period of storage of set-style yogurt produced from heat-treated milk and viscosity value.

scholarly journals The influence of investigated factors on viscosity of stirred yogurt

2002 ◽  
Vol 47 (2) ◽  
pp. 219-231 ◽  
Author(s):  
Jelena Denin-Djurdjevic ◽  
Ognjen Macej ◽  
Snezana Jovanovic
Keyword(s):  
Milk Sample ◽  
Skim Milk ◽  
Streptococcus Thermophilus ◽  
Matter Content ◽  
Lactobacillus Delbrueckii ◽  
Dry Matter Content ◽  
90 C 10 ◽  
Milk Samples ◽  
Heat Treated ◽  
Control Milk

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.

scholarly journals Viscosity and Analytical Differences between Raw Milk and UHT Milk of Czech Cows

2015 ◽  
Vol 46 (2) ◽  
pp. 78-83 ◽  
Author(s):  
V. Kumbár ◽  
Š. Nedomová
Keyword(s):  
Dynamic Viscosity ◽  
Kinematic Viscosity ◽  
Dry Matter ◽  
Titratable Acidity ◽  
Raw Milk ◽  
Matter Content ◽  
Dry Matter Content ◽  
Uht Milk ◽  
Milk Samples ◽  
Milk Flow

Abstract Viscosity and analytical differences in four milk samples from Czech cows were described. Three samples of UHT milk (0.5%, 1.5%, and 3.5% fat) and one sample of raw milk from a Czech bio-farm were analyzed. The following analytical properties were observed: titratable acidity, fat content, dry matter content, and protein content. Titratable acidity and dry matter content decreased in dependence upon the increasing milk fat content. The protein content ranged 3.51-3.57 g per 100 g milk. The milk flow behaviour represented by density, dynamic and kinematic viscosity, as well as the dependence of the milk flow behaviour on temperature were investigated. These properties were measured using a digital densitometer and a rotary viscometer. Milk density was studied at temperatures ranging 0-60 °C and dynamic viscosity at 0-100 °C. With increasing temperature, the density and dynamic viscosity of the studied milk samples decreased. The temperature dependence of dynamic viscosity was manifested in all samples. Kinematic viscosity was calculated from experimental data. Furthermore, mathematical models using Power law and Gaussian fitting were constructed. Determination coefficients achieved high values (0.843-0.997).

scholarly journals The influence of applied heat treatments on whey protein denaturation

2002 ◽  
Vol 47 (2) ◽  
pp. 205-218
Author(s):  
Safet Fetahagic ◽  
Ognjen Macej ◽  
Jelena Denin-Djurdjevic ◽  
Snezana Jovanovic
Keyword(s):  
Heat Treatment ◽  
Whey Protein ◽  
Protein Denaturation ◽  
Skim Milk ◽  
Heat Treatments ◽  
Matter Content ◽  
90 C 10 ◽  
Milk Samples ◽  
Heat Treated ◽  
Sera Samples

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%.

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

2002 ◽  
Vol 47 (2) ◽  
pp. 189-204 ◽  
Author(s):  
Jelena Denin-Djurdjevic ◽  
Ognjen Macej ◽  
Snezana Jovanovic
Keyword(s):  
Heat Treatment ◽  
Dry Matter ◽  
Milk Powder ◽  
Skim Milk ◽  
Storage Period ◽  
Matter Content ◽  
Lactobacillus Delbrueckii ◽  
Dry Matter Content ◽  
90 C 10 ◽  
Heat Treated

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.

scholarly journals Esmer İneklerde Somatik Hücre Sayısı ve Bazı Çiğ Süt Parametreleri Arasındaki İlişkilerin Belirlenmesi

2014 ◽  
Vol 2 (5) ◽  
pp. 220
Author(s):  
Aziz Şahin ◽  
Muzaffer Kaşıkcı
Keyword(s):  
Dry Matter ◽  
Milk Composition ◽  
Matter Content ◽  
Standard Errors ◽  
Dry Matter Content ◽  
Brown Swiss ◽  
Milk Samples ◽  
Upper Limit ◽  
The One ◽  
The Relationship

The aim of the present research was to determine the relationship between somatic cell count (SCC) and milk composition. Milk samples were collected in November and May in 2012. In the study, 128 milk samples from Brown Swiss cattle, divided into two groups. They were arranged from low score (≤500 000cell/ml) to high score (>500 000cell/ml) according to the Turkish Food Codex upper limit. The averages of SCC were determined as 10.444±0.073cells/ml for first group and 10.820±0.088cells/ml for second group, respectively. In the one group dry matter, non fat dry matter, fat, protein, lactose levels and standard errors were determined as 13.3±0.60%, 8.3±0.21%, 4.5±0.61%, 3.0±0.14% and 4.7±0.07%, respectively. The other group same traits were calculated 13.7±0.17%, 7.9±0.10%, 5.8±0.14%, 3.0±0.06% and 4.1±0.05%, respectively. Significant correlations were found between SCC and non fat dry matter (r=-0.109) protein (r=0.145), lactose (r=-0.490) in the second group. But, non significant correlations were determined between SCC and dry matter, non fat dry matter, fat, protein and lactose in the first group. As a result, increasing of the number of somatic cells, milk, lactose, protein, and fat-free dry matter content was determined to be significantly affected.

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

2002 ◽  
Vol 47 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Jelena Djurdjevic-Denin ◽  
Ognjen Macej ◽  
Snezana Jovanovic
Keyword(s):  
Heat Treatment ◽  
Milk Powder ◽  
Skim Milk ◽  
Matter Content ◽  
Lactobacillus Delbrueckii ◽  
Dry Matter Content ◽  
90 C 10 ◽  
Milk Samples ◽  
Whey Powder ◽  
Heat Treated

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.

Optimum harvest date of maize for biogas and silage purposes

2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi
Keyword(s):  
Dry Matter ◽  
Biogas Production ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Dry Mass ◽  
Matter Content ◽  
Harvest Date ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Vegetative Organs

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.

Persistence of modern varieties and hybrids of carrots and its dependence on the biochemical composition

2020 ◽  
pp. 16-19
Author(s):  
Е.В. Янченко
Keyword(s):  
Botrytis Cinerea ◽  
Sclerotinia Sclerotiorum ◽  
Dry Matter ◽  
Inverse Correlation ◽  
Dry Weight ◽  
Matter Content ◽  
White Rot ◽  
Dry Matter Content ◽  
Important Indicator ◽  
Modern Varieties

Цель исследований – дать оценку сохраняемости и болезнеустойчивости современных сортов и гибридов моркови столовой и определить корреляционные зависимости влияния биохимических показателей качества на сохраняемость и степень поражения моркови столовой различными видами болезней в процессе хранения. Исследования проводились в 2011–2016 годах во ВНИИО – филиале ФГБНУ ФНЦО по общепринятым методикам. В биохимической лаборатории отдела земледелия и агрохимии содержание сухого вещества определяли высушиванием до абсолютно сухого веса, общего сахара – по Бертрану, аскорбиновой кислоты – по Мурри, нитраты – ионоселективным методом. При характеристике моркови столовой важнейший показатель, определяющий его качество – количество сухого вещества и сахаров. В процессе хранения были выявлены следующие болезни моркови: серая гниль (Botrytis cinerea Pers. ex Fr.), белая гниль (Sclerotinia sclerotiorum (Lib.)), белая парша (Rhizoctonia carotae Rad.), альтернариоз (Alternaria radicina M., Dr. et E.). В большей степени сортообразцы моркови столовой поражались серой гнилью. Лучшими по сохраняемости сортообразцами были Корсар (94,6%), F1Берлин (94,5%), Берликум Роял (94,1%) и F1 Звезда (94%). Сохраняемость у зарубежных сортов и гибридов моркови столовой была немного выше, чем у отечественных (на 0,4%) как за счет меньшей величины убыли массы (6,3% против 6,4%), так и потерь от болезней (1,6% против 1,9%). Сохраняемость корнеплодов моркови находится в прямой корреляционной зависимости от содержания сухого вещества (r=+0,41), каротиноидов (r=+0,39), моносахаров (r­=+0,30) и суммы сахаров (r=+0,27). Проявление серой гнили находится в обратной корреляционной связи с содержанием сухого вещества и каротиноидов (r=-0,37 и r=-0,35 соответственно), белой парши – в прямой корреляции с содержанием сухого вещества , моносахаров и дисахаров (r= +0,21; r= +0,39; r= -0,41 соответственно), белой гнили в обратной корреляционной связи с содержанием сухого вещества, моносахаров и дисахаров. The purpose of the research is to assess the persistence and disease resistance of modern varieties and hybrids of carrots and to determine the correlation between the influence of biochemical quality indicators on the persistence and degree of damage to carrots by various types of diseases during storage. The research was conducted in 2011–2016 at ARRIVG – branch of FSBSI FSVC, according to generally accepted methods. In the biochemical laboratory of the Department of Agriculture and Agrochemistry, the dry matter content was determined by drying to absolutely dry weight, total sugar – by Bertran, ascorbic acid – by Murri, nitrates – by the ion-selective method. When describing carrots, the most important indicator that determines its quality is the amount of dry matter and sugars. During storage, the following diseases of carrots were detected: gray rot (Botrytis cinerea Pers. ex Fr.), white rot (Sclerotinia sclerotiorum (Lib.), white scab (Rhizoctonia carotae Rad.), alternariasis (Alternaria radicina M., Dr. et E.). To a greater extent, varieties of table carrots were affected by gray rot. The best preserved varieties were Corsar (94.6%), F1 Berlin (94.5%), Berlicum Royal (94.1%) and F1 Zvezda (94%). The persistence of foreign varieties and hybrids of table carrots was slightly higher than that of domestic ones by 0.4%. both due to a smaller amount of weight loss (6.3% vs. 6.4%) and losses from diseases (1.6% vs. 1.9%). The persistence of carrot root crops is directly correlated with the content of dry matter (r=+0.41), carotenoids (r=+0.39), monosaccharides (r=+0.30) and the amount of sugars (r=+0.27). The manifestation of gray rot is in inverse correlation with the content of dry matter and carotenoids (r=-0.37 and r=-0.35, respectively), white scab is in direct correlation with the content of dry matter (r= +0.21; r= +0.39; r= –0.41, respectively), white rot is in inverse correlation with the content of dry matter, monosaccharides and disaccharides.

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