Darbo tikslas: nustatyti racionų baltymų kiekio ir kokybės įtaką karvių produktyvumui ir pieno kokybei. Darbo uždaviniai: apskaičiuoti karvėms šertų racionų energinę ir maistinę vertę. Nustatyti racionų baltymų kiekio ir kokybės įtaką karvių produktyvumui. Nustatyti racionų baltymų kiekio ir kokybės įtaką karvių pieno sudėčiai. Bandymas atliktas 2012 metais X ūkininko galvijininkystės ūkyje. Darbo tikslas buvo nustatyti racionų baltymų kiekio ir kokybės įtaką karvių produktyvumui ir pieno sudėčiai. Analogų principu atrinkta 20 karvių, kurios suskirstytos į 4 grupes (3 tiriamųjų ir 1 kontrolinė), po 5 gyvulius kiekvienoje. Vidutinis karvių produktyvumas per ankstesnę laktaciją buvo 6000 – 6300 kg pieno. Eksperimentiniais racionais karvės šertos keturis mėnesius sausio - balandžio mėn., t.y. pirmąsias 120 laktacijos dienų. Kitu laikotarpiu buvo tik registruojami produktyvumo ir pieno sudėties duomenys. Išanalizavę 2011–2012 metų X ūkio karvių racionus, jų sudėtį, energinę ir maistinę vertę, įvertinę skirtingo šėrimo poveikį produktyvumui ir produkcijos kokybei nustatėme: Didžiausias produktyvumas buvo antros grupės karvių. Lyginant su kontroline grupe, natūralaus pieno iš jų buvo primelžta 228 kg (p<0,05), o perskaičiuoto į bazinį - 666 kg (p<0,01) daugiau. Mažiausias primilžis per 10 laktacijos mėnesių buvo kontrolinės grupės karvių. Jos davė 300 kg mažiau natūralaus pieno arba 965 kg perskaičiuoto į bazinį pieną negu II (produktyviausios) grupės karvės. Daugiausia pieno... [toliau žr. visą tekstą] / The aim: to identify the diet of protein quantity and quality on cow productivity and milk quality. The tasks of the work: to calculate the cows fed rations energy content and nutritional value. Set the ration protein content and quality on milk production of cows. Set the ration protein content and quality on the composition of cow's milk. Experiment was carried out in 2012 X farmer's cattle farm. The aim of the research was to identify the ration protein content and quality on cow productivity and milk composition. Analogues of the principle of sample 20 cows, which are divided into 4 groups (3 test and 1 control), followed by five animals each. The average of productivity per cow during the previous lactation was 6000 - 6300 kg of milk. Cows were fed the experimental diets for four months of January - April., that is to say the first 120 days of lactation. The next period, there were only recorded productivity and milk composition data. The analysis of X holding the 2011-2012 cows fed rations composition, nutritional indicators, the results obtained. The maximum productivity was the second group of cows comparison with a control group of natural milk from their milk yield was 228 kg (p <0.05), and the terms of base - 666 kg (p <0.01) and more. Minimum yield within 10 months of lactation were control cows. They gave 300 kilos of liquid milk, or 965 kg of milk in terms of base than in the second (productive) group of cows. Most milk fat obtained from the second treatment... [to full text]

Emulsions form a major part of processed food formulations, either being the end products in themselves or as parts of a more complex food system. For the past few decades, colloid scientists have focussed mainly on the effects of processing conditions (e.g. heat, high pressure, and shear) on the physicochemical properties of emulsions (e.g. viscosity, droplet size distribution and phase stability). However, the information about the behaviour of food structures post consumption is very limited. Fundamental knowledge of how the food structures behave in the mouth is critical, as these oral interactions of food components influence the common sensorial perceptions (e.g. creaminess, smoothness) and the release of fat-soluble flavours. Initial studies also suggest that the breakdown of emulsions in the gastrointestinal tract and the generated interfacial structures impact lipid digestion, which can consequently influence post-prandial metabolic responses. This area of research needs to be intensively investigated before the knowledge can be applied to rational design of healthier food structures that could modulate the rate of lipid metabolism, bioavailability of nutrients, and also help in providing targeted delivery of flavour molecules and/or bioactive components. Hence, the objective of this research was to gain understanding of how emulsions behave during their passage through the gastrointestinal tract. In vitro digestion models that mimic the physicochemical processes and biological conditions in the mouth and gastrointestinal tract were successfully employed. Behaviour of model protein-stabilized emulsions (both positively charged (lactoferrin) as well as negatively charged [β-lactoglobulin (β-lg)] oil-in-water emulsions) at each step of simulated physiological processing (using model oral, gastric and duodenal fluids individually) were investigated. In simulated mouth conditions, oil-in-water emulsions stabilized by lactoferrin or β-lg at the interfacial layers were mixed with artificial saliva at neutral pH that contained a range of mucin concentrations and salts. The β-lg emulsions did not interact with the artificial saliva due to the dominant repulsion between mutually opposite charges of anionic mucin and anionic β-lg interfacial layer at neutral pH. However, β-lg emulsions underwent some depletion flocculation on addition of higher concentrations of mucin due to the presence of unadsorbed mucin molecules in the continuous phase. In contrast, positively charged lactoferrin emulsions showed considerable salt-induced aggregation in the presence of salts (from the saliva) alone. Furthermore, lactoferrin emulsions underwent bridging flocculation because of electrostatic binding of anionic mucin to the positively charged lactoferrin-stabilized emulsion droplets. In acidic pH conditions (pH 1.2) of the simulated gastric fluid (SGF), both protein-stabilized emulsions were positively charged. Addition of pepsin resulted in extensive droplet flocculation in both emulsions with a greater extent of droplet instability in lactoferrin emulsions. Coalescence of the droplets was observed as a result of peptic hydrolysis of the interfacial protein layers. Conditions such as ionic strength, pH and exposure to mucin were shown to significantly influence the rate of hydrolysis of β-lg-stabilized emulsion by pepsin. Addition of simulated intestinal fluid (SIF) containing physiological concentrations of bile salts to the emulsions showed competitive interfacial displacement of β-lg by bile salts. In the case of lactoferrin-stabilized emulsion droplets, there was considerable aggregation in the presence of intestinal electrolytes alone (without added bile salts) at pH 7.5. Binding of anionic bile salts to cationic interfacial lactoferrin layer resulted in re-stabilization of salt-aggregated lactoferrin emulsions. On mixing with physiological concentrations of pancreatin (mixture of pancreatic lipase, amylase and protease), significant degree of coalescence and fatty acid release occurred for both the emulsions. This was attributed to the interfacial proteolysis by trypsin (proteolytic fractions of pancreatin) resulting in interfacial film rupturing. Exchange of initial interfacial materials by bile salts and trypsin-induced film breakage enhanced the potential for lipolytic fractions of pancreatin to act on the hydrophobic lipid core. The lipid digestion products (free fatty acids and mono and/or diglycerides) generated at the droplet surface further removed the residual intact protein layers from the interface by competitive displacement mechanisms. The sequential treatment of the cationic and anionic emulsions with artificial saliva, SGF and SIF, respectively, was determined to understand the impact of initial protein type during complete physiological processing from mouth to intestine. Broadly, both the protein-stabilized emulsions underwent charge reversals, extensive droplet flocculation, and significant coalescence as they passed through various stages of the in vitro digestion conditions. Except in the simulated mouth environment, the initial charge of the emulsifiers had relatively limited influence on droplet behaviour during the simulated digestion. The results contribute to the knowledge of how structure and charge of the emulsified lipid droplets impact digestion at various stages of physiology. This information might have important consequences for developing suitable microstructures that allow controlled breakdown of droplets in the mouth and predictable release of lipids in the gastrointestinal tract.

Emulsions form a major part of processed food formulations, either being the end products in themselves or as parts of a more complex food system. For the past few decades, colloid scientists have focussed mainly on the effects of processing conditions (e.g. heat, high pressure, and shear) on the physicochemical properties of emulsions (e.g. viscosity, droplet size distribution and phase stability). However, the information about the behaviour of food structures post consumption is very limited. Fundamental knowledge of how the food structures behave in the mouth is critical, as these oral interactions of food components influence the common sensorial perceptions (e.g. creaminess, smoothness) and the release of fat-soluble flavours. Initial studies also suggest that the breakdown of emulsions in the gastrointestinal tract and the generated interfacial structures impact lipid digestion, which can consequently influence post-prandial metabolic responses. This area of research needs to be intensively investigated before the knowledge can be applied to rational design of healthier food structures that could modulate the rate of lipid metabolism, bioavailability of nutrients, and also help in providing targeted delivery of flavour molecules and/or bioactive components. Hence, the objective of this research was to gain understanding of how emulsions behave during their passage through the gastrointestinal tract. In vitro digestion models that mimic the physicochemical processes and biological conditions in the mouth and gastrointestinal tract were successfully employed. Behaviour of model protein-stabilized emulsions (both positively charged (lactoferrin) as well as negatively charged [β-lactoglobulin (β-lg)] oil-in-water emulsions) at each step of simulated physiological processing (using model oral, gastric and duodenal fluids individually) were investigated. In simulated mouth conditions, oil-in-water emulsions stabilized by lactoferrin or β-lg at the interfacial layers were mixed with artificial saliva at neutral pH that contained a range of mucin concentrations and salts. The β-lg emulsions did not interact with the artificial saliva due to the dominant repulsion between mutually opposite charges of anionic mucin and anionic β-lg interfacial layer at neutral pH. However, β-lg emulsions underwent some depletion flocculation on addition of higher concentrations of mucin due to the presence of unadsorbed mucin molecules in the continuous phase. In contrast, positively charged lactoferrin emulsions showed considerable salt-induced aggregation in the presence of salts (from the saliva) alone. Furthermore, lactoferrin emulsions underwent bridging flocculation because of electrostatic binding of anionic mucin to the positively charged lactoferrin-stabilized emulsion droplets. In acidic pH conditions (pH 1.2) of the simulated gastric fluid (SGF), both protein-stabilized emulsions were positively charged. Addition of pepsin resulted in extensive droplet flocculation in both emulsions with a greater extent of droplet instability in lactoferrin emulsions. Coalescence of the droplets was observed as a result of peptic hydrolysis of the interfacial protein layers. Conditions such as ionic strength, pH and exposure to mucin were shown to significantly influence the rate of hydrolysis of β-lg-stabilized emulsion by pepsin. Addition of simulated intestinal fluid (SIF) containing physiological concentrations of bile salts to the emulsions showed competitive interfacial displacement of β-lg by bile salts. In the case of lactoferrin-stabilized emulsion droplets, there was considerable aggregation in the presence of intestinal electrolytes alone (without added bile salts) at pH 7.5. Binding of anionic bile salts to cationic interfacial lactoferrin layer resulted in re-stabilization of salt-aggregated lactoferrin emulsions. On mixing with physiological concentrations of pancreatin (mixture of pancreatic lipase, amylase and protease), significant degree of coalescence and fatty acid release occurred for both the emulsions. This was attributed to the interfacial proteolysis by trypsin (proteolytic fractions of pancreatin) resulting in interfacial film rupturing. Exchange of initial interfacial materials by bile salts and trypsin-induced film breakage enhanced the potential for lipolytic fractions of pancreatin to act on the hydrophobic lipid core. The lipid digestion products (free fatty acids and mono and/or diglycerides) generated at the droplet surface further removed the residual intact protein layers from the interface by competitive displacement mechanisms. The sequential treatment of the cationic and anionic emulsions with artificial saliva, SGF and SIF, respectively, was determined to understand the impact of initial protein type during complete physiological processing from mouth to intestine. Broadly, both the protein-stabilized emulsions underwent charge reversals, extensive droplet flocculation, and significant coalescence as they passed through various stages of the in vitro digestion conditions. Except in the simulated mouth environment, the initial charge of the emulsifiers had relatively limited influence on droplet behaviour during the simulated digestion. The results contribute to the knowledge of how structure and charge of the emulsified lipid droplets impact digestion at various stages of physiology. This information might have important consequences for developing suitable microstructures that allow controlled breakdown of droplets in the mouth and predictable release of lipids in the gastrointestinal tract.

Emulsions form a major part of processed food formulations, either being the end products in themselves or as parts of a more complex food system. For the past few decades, colloid scientists have focussed mainly on the effects of processing conditions (e.g. heat, high pressure, and shear) on the physicochemical properties of emulsions (e.g. viscosity, droplet size distribution and phase stability). However, the information about the behaviour of food structures post consumption is very limited. Fundamental knowledge of how the food structures behave in the mouth is critical, as these oral interactions of food components influence the common sensorial perceptions (e.g. creaminess, smoothness) and the release of fat-soluble flavours. Initial studies also suggest that the breakdown of emulsions in the gastrointestinal tract and the generated interfacial structures impact lipid digestion, which can consequently influence post-prandial metabolic responses. This area of research needs to be intensively investigated before the knowledge can be applied to rational design of healthier food structures that could modulate the rate of lipid metabolism, bioavailability of nutrients, and also help in providing targeted delivery of flavour molecules and/or bioactive components. Hence, the objective of this research was to gain understanding of how emulsions behave during their passage through the gastrointestinal tract. In vitro digestion models that mimic the physicochemical processes and biological conditions in the mouth and gastrointestinal tract were successfully employed. Behaviour of model protein-stabilized emulsions (both positively charged (lactoferrin) as well as negatively charged [β-lactoglobulin (β-lg)] oil-in-water emulsions) at each step of simulated physiological processing (using model oral, gastric and duodenal fluids individually) were investigated. In simulated mouth conditions, oil-in-water emulsions stabilized by lactoferrin or β-lg at the interfacial layers were mixed with artificial saliva at neutral pH that contained a range of mucin concentrations and salts. The β-lg emulsions did not interact with the artificial saliva due to the dominant repulsion between mutually opposite charges of anionic mucin and anionic β-lg interfacial layer at neutral pH. However, β-lg emulsions underwent some depletion flocculation on addition of higher concentrations of mucin due to the presence of unadsorbed mucin molecules in the continuous phase. In contrast, positively charged lactoferrin emulsions showed considerable salt-induced aggregation in the presence of salts (from the saliva) alone. Furthermore, lactoferrin emulsions underwent bridging flocculation because of electrostatic binding of anionic mucin to the positively charged lactoferrin-stabilized emulsion droplets. In acidic pH conditions (pH 1.2) of the simulated gastric fluid (SGF), both protein-stabilized emulsions were positively charged. Addition of pepsin resulted in extensive droplet flocculation in both emulsions with a greater extent of droplet instability in lactoferrin emulsions. Coalescence of the droplets was observed as a result of peptic hydrolysis of the interfacial protein layers. Conditions such as ionic strength, pH and exposure to mucin were shown to significantly influence the rate of hydrolysis of β-lg-stabilized emulsion by pepsin. Addition of simulated intestinal fluid (SIF) containing physiological concentrations of bile salts to the emulsions showed competitive interfacial displacement of β-lg by bile salts. In the case of lactoferrin-stabilized emulsion droplets, there was considerable aggregation in the presence of intestinal electrolytes alone (without added bile salts) at pH 7.5. Binding of anionic bile salts to cationic interfacial lactoferrin layer resulted in re-stabilization of salt-aggregated lactoferrin emulsions. On mixing with physiological concentrations of pancreatin (mixture of pancreatic lipase, amylase and protease), significant degree of coalescence and fatty acid release occurred for both the emulsions. This was attributed to the interfacial proteolysis by trypsin (proteolytic fractions of pancreatin) resulting in interfacial film rupturing. Exchange of initial interfacial materials by bile salts and trypsin-induced film breakage enhanced the potential for lipolytic fractions of pancreatin to act on the hydrophobic lipid core. The lipid digestion products (free fatty acids and mono and/or diglycerides) generated at the droplet surface further removed the residual intact protein layers from the interface by competitive displacement mechanisms. The sequential treatment of the cationic and anionic emulsions with artificial saliva, SGF and SIF, respectively, was determined to understand the impact of initial protein type during complete physiological processing from mouth to intestine. Broadly, both the protein-stabilized emulsions underwent charge reversals, extensive droplet flocculation, and significant coalescence as they passed through various stages of the in vitro digestion conditions. Except in the simulated mouth environment, the initial charge of the emulsifiers had relatively limited influence on droplet behaviour during the simulated digestion. The results contribute to the knowledge of how structure and charge of the emulsified lipid droplets impact digestion at various stages of physiology. This information might have important consequences for developing suitable microstructures that allow controlled breakdown of droplets in the mouth and predictable release of lipids in the gastrointestinal tract.

Emulsions form a major part of processed food formulations, either being the end products in themselves or as parts of a more complex food system. For the past few decades, colloid scientists have focussed mainly on the effects of processing conditions (e.g. heat, high pressure, and shear) on the physicochemical properties of emulsions (e.g. viscosity, droplet size distribution and phase stability). However, the information about the behaviour of food structures post consumption is very limited. Fundamental knowledge of how the food structures behave in the mouth is critical, as these oral interactions of food components influence the common sensorial perceptions (e.g. creaminess, smoothness) and the release of fat-soluble flavours. Initial studies also suggest that the breakdown of emulsions in the gastrointestinal tract and the generated interfacial structures impact lipid digestion, which can consequently influence post-prandial metabolic responses. This area of research needs to be intensively investigated before the knowledge can be applied to rational design of healthier food structures that could modulate the rate of lipid metabolism, bioavailability of nutrients, and also help in providing targeted delivery of flavour molecules and/or bioactive components. Hence, the objective of this research was to gain understanding of how emulsions behave during their passage through the gastrointestinal tract. In vitro digestion models that mimic the physicochemical processes and biological conditions in the mouth and gastrointestinal tract were successfully employed. Behaviour of model protein-stabilized emulsions (both positively charged (lactoferrin) as well as negatively charged [β-lactoglobulin (β-lg)] oil-in-water emulsions) at each step of simulated physiological processing (using model oral, gastric and duodenal fluids individually) were investigated. In simulated mouth conditions, oil-in-water emulsions stabilized by lactoferrin or β-lg at the interfacial layers were mixed with artificial saliva at neutral pH that contained a range of mucin concentrations and salts. The β-lg emulsions did not interact with the artificial saliva due to the dominant repulsion between mutually opposite charges of anionic mucin and anionic β-lg interfacial layer at neutral pH. However, β-lg emulsions underwent some depletion flocculation on addition of higher concentrations of mucin due to the presence of unadsorbed mucin molecules in the continuous phase. In contrast, positively charged lactoferrin emulsions showed considerable salt-induced aggregation in the presence of salts (from the saliva) alone. Furthermore, lactoferrin emulsions underwent bridging flocculation because of electrostatic binding of anionic mucin to the positively charged lactoferrin-stabilized emulsion droplets. In acidic pH conditions (pH 1.2) of the simulated gastric fluid (SGF), both protein-stabilized emulsions were positively charged. Addition of pepsin resulted in extensive droplet flocculation in both emulsions with a greater extent of droplet instability in lactoferrin emulsions. Coalescence of the droplets was observed as a result of peptic hydrolysis of the interfacial protein layers. Conditions such as ionic strength, pH and exposure to mucin were shown to significantly influence the rate of hydrolysis of β-lg-stabilized emulsion by pepsin. Addition of simulated intestinal fluid (SIF) containing physiological concentrations of bile salts to the emulsions showed competitive interfacial displacement of β-lg by bile salts. In the case of lactoferrin-stabilized emulsion droplets, there was considerable aggregation in the presence of intestinal electrolytes alone (without added bile salts) at pH 7.5. Binding of anionic bile salts to cationic interfacial lactoferrin layer resulted in re-stabilization of salt-aggregated lactoferrin emulsions. On mixing with physiological concentrations of pancreatin (mixture of pancreatic lipase, amylase and protease), significant degree of coalescence and fatty acid release occurred for both the emulsions. This was attributed to the interfacial proteolysis by trypsin (proteolytic fractions of pancreatin) resulting in interfacial film rupturing. Exchange of initial interfacial materials by bile salts and trypsin-induced film breakage enhanced the potential for lipolytic fractions of pancreatin to act on the hydrophobic lipid core. The lipid digestion products (free fatty acids and mono and/or diglycerides) generated at the droplet surface further removed the residual intact protein layers from the interface by competitive displacement mechanisms. The sequential treatment of the cationic and anionic emulsions with artificial saliva, SGF and SIF, respectively, was determined to understand the impact of initial protein type during complete physiological processing from mouth to intestine. Broadly, both the protein-stabilized emulsions underwent charge reversals, extensive droplet flocculation, and significant coalescence as they passed through various stages of the in vitro digestion conditions. Except in the simulated mouth environment, the initial charge of the emulsifiers had relatively limited influence on droplet behaviour during the simulated digestion. The results contribute to the knowledge of how structure and charge of the emulsified lipid droplets impact digestion at various stages of physiology. This information might have important consequences for developing suitable microstructures that allow controlled breakdown of droplets in the mouth and predictable release of lipids in the gastrointestinal tract.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 5 uppsatser.

The aim of the thesis is to study the influence of the milk protein beta-lactoglobulin on the milk renneting properties. Based on the polymorphisms in -lactoglobulin gene (BLG), the genotypes AA, AB and BB were defined by the method PCR-RFLP in the case of 730 dairy cows. The results of the genotypes analysis show that in the studied population the heterozygotes AB occur approximately eleven times more often than homozygotes BB and thirty times more often than homozygotes AA. The allele A frequency was 0.4732 and the allele B 0.5268. The genotype BLG influence on production traits of milk was analysed in the aggregate of 429 milk samples. The statistically demonstrative allele B influence on the percentage of proteins representation was found only in one group of dairy cattle from farm Sedlec. The alleles BB were associated with lower values of these parameters. The statistically significant difference influenced by the genotypes or the gene BLG alleles was not found in any other measurement. In the thesis the testing of milk renneting properties by the rennet coagulation time (RCT) and the determination of titratable acidity in milk was made on 51 samples. The results show that the BLG genotypes had no influence on the RCT. In the determination of titratable acidity in milk results the genotype influence appeared and the p-value is lower than the given significance level = 0.05. It could mean that the AB genotype is connected with the higher milk acidity. However, the results can be distorted by the low numbers of the population.

Made available in DSpace on 2014-06-11T19:27:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-24Bitstream added on 2014-06-13T18:56:19Z : No. of bitstreams: 1 panichi_a_me_botfmvz.pdf: 196980 bytes, checksum: 61d5f9be85432766fb8c0cea59cad982 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Vacas com alto potencial para produção de leite requerem suplementação com alimentos concentrados para suprir suas exigências nutricionais. A utilização do milho como parte desses alimentos torna-se freqüente, já que é a fonte de amido mais utilizada. Com o objetivo de avaliar os efeitos da substituição dos grãos secos de milho (GSM) pela silagem de grãos úmidos de milho (SGUM) sobre a produção e composição do leite, foram utilizadas cinco vacas da raça Holandesas (HPB), primíparas com média de 112 dias pós-parto, confinadas em Tie Stall, no setor de Bovinocultura Leiteira da Universidade de Marília – UNIMAR. Foram avaliadas cinco rações balanceadas de acordo com o NRC (2001) para 17,5% PB (MS) e 2,4 Mcal EM/kg MS, contendo farelo de soja, GSM e/ou SGUM, silagem de cana de açúcar e feno. Níveis de substituição dos GSM pela SGUM estão descritos nos tratamentos: 1) 0%; 2) 25%; 3) 50%; 4) 75% e 5) 100%. O período experimental teve duração de 70 dias, divididos em cinco fases de 14 dias cada. A produção de leite e o consumo de matéria seca foram registrados diariamente. Os animais foram submetidos a duas ordenhas diárias (6:00 e 18:00 h), sendo as amostras de leite coletadas nas ordenhas consecutivas de cada fase experimental (quatro dias de coleta). O delineamento experimental utilizado foi o Quadrado Latino 5x5 e os dados analisados pelo programa estatístico SAS. O peso corporal (508 kg), produção de leite (23,6 kg), produção de leite corrigida (22,7 kg), consumos de matéria seca (17,13 kg), não apresentaram diferença com a inclusão da SGUM na dieta, porém os consumos de FDN (6,67 kg), FDA (3,39 kg) e eficiência alimentar para produção de leite (1,41 kg leite/dia), apresentaram diferença. Para a composição do leite, apenas o nitrogênio uréico (17,67 mg/dL) apresentou diferença com a inclusão de SGUM na dieta, indicando desta forma... / Cows with high potential for milk production require extra concentrated food in order to supply their nutritional demands. The use of corn as part of their feeding has been frequent, since it is the most used source of starch. Intended for evaluating the effects of the substitution of the dry shelled corn (DSC) for the high moisture corn silage (HMCS) on the production and composition of the milk, five Holstein cows (BWH) were used. They were primiparous, with a postpartum time of around 112 days, confined in Tie Stall, in the dairy cattle sector of the University of Marília - UNIMAR. It was evaluated five rations balanced in agreement with NRC (2001) to 17.5% CP (DM) and 2.4 Mcal ME/kg DM, containing soybean meal, DSC and/or HMCS, sugar silage and hay. Levels of substitution of DSC for the HMCS are described in the treatments: 1) 0%; 2) 25%; 3) 50%; 4) 75% and 5) 100%. The experimental period was 70 days, divided into five phases of 14 days each. The production of milk and consumption of dry matter were registered daily. The animals were submitted to two milk daily rates (6h00 and 18h00), and the milk samples were collected in the following milking of each experimental phase (four days of collection). It was used the method of Latin Square 5x5 and the data analyzed by the SAS statistical program. Body weight (508 kg), production of milk (23.6 kg), production of milk corrected for 4% of fat (22.7 kg), and dry matter consumptions (17.13 kg) did not present any difference with the inclusion of HMCS in the diet, unlike the FDN (6.67 kg), FDA (3.39 kg) intake and feed efficiency production of milk (1.41 kg milk/day) presented difference. As for the composition of the milk, only the urea nitrogen (17.67 mg/dL) presented difference with the inclusion of HMCS in the diet, thus indicating that HMCS... (Complete abstract click electronic access below)

Master of Science / Food Science Institute / Jayendra K. Amamcharla / Milk protein concentrate (MPC) powders are high-protein dairy ingredients obtained from membrane filtration processes and subsequent spray drying. MPC powders have extensive applications due to their nutritional, functional, and sensory properties. However, their flow properties, rehydration behavior, and morphological characteristics are affected by various factors such as processing, storage, particle size, and composition of the powder. Literature has shown that knowledge about the powder flowability characteristics is critical in their handling, processing, and subsequent storage. For this study, FT4 powder rheometer (FT4, Freeman Technologies, UK) was used to characterize the flowability of MPC powders during storage. This study investigated the flowability and morphological characteristics of commercial MPC powders with three different protein contents (70, 80, and 90%, w/w) after storage at 25ºC and 40ºC for 12 weeks. Powder flow properties (basic flowability energy (BFE), flow rate index (FRI), permeability, etc.) and shear properties (cohesion, flow function, etc.) were evaluated. After 12 weeks of storage at 40ºC, the BFE and FRI values significantly increased (P < 0.05) as the protein content increased from 70 to 90% (w/w). Dynamic flow tests indicated that MPC powders with high protein contents displayed higher permeability. Shear tests confirmed that samples stored at 40ºC were relatively less flowable than samples stored at 25ºC. Also, the lower protein content samples showed better shear flow behavior. The results indicated that MPC powders stored at 40ºC had more cohesiveness and poor flow characteristics than MPC powders stored at 25ºC. The circle equivalent diameter, circularity, and elongation of MPC powders increased as protein content and storage temperature increased, while the convexity decreased as protein content and storage temperature increased. Overall, the MPC powders evidently showed different flow properties and morphological characteristics due to their difference in composition and storage temperature. Literature has shown various methods for determining the solubility of dairy powders, but it requires expensive instruments and skilled technicians. The front-face fluorescence spectroscopy (FFFS) coupled with chemometrics could be used as an efficient alternative, which is commonly used as fingerprints of the various food products. To evaluate FFFS as a useful tool for the non-destructive measurement of solubility in the MPC powders, commercially procured MPC powders were stored at two temperatures (25 and 40ºC) for 1, 2, 4, 8, and 12 weeks to produce powders with different rehydration properties, which subsequently influenced their fluorescence spectra. The spectra of tryptophan and Maillard products were recorded and analyzed with principal components analysis. The solubility index and the relative dissolution index (RDI) obtained from focused beam reflectance measurement was used to predict solubility and dissolution changes using fluorescence spectra of tryptophan and Maillard products. The solubility index and RDI showed that the MPC powders had decreased solubility as the storage time and temperature increased. The results suggest that FFFS has the potential to provide rapid, nondestructive, and accurate measurements of rehydration behavior in MPC powders. Overall, the results indicated that solubility and dissolution behavior of MPC powders were related to protein content and storage conditions that could be measured using FFFS.