An Aspergillus niger UFV-1 phytase was characterized and made available for industrial application. The enzyme was purified via ultrafiltration followed by acid precipitation, ion exchange and gel filtration chromatography. This protein exhibited a molecular mass of 161 kDa in gel filtration and 81 kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), indicating that it may be a dimer. It presented an optimum temperature of 60 °C and optimum pH of 2.0. The K M for sodium phytate hydrolysis was 30.9 mM, while the k cat and k cat / K M were 1.46 ×10 5 s −1 and 4.7 × 10 6 s −1 .M −1 , respectively. The purified phytase exhibited broad specificity on a range of phosphorylated compounds, presenting activity on sodium phytate, p-NPP, 2- naphthylphosphate, 1- naphthylphosphate, ATP, phenyl-phosphate, glucose-6-phosphate, calcium phytate and other substrates. Enzymatic activity was slightly inhibited by Mg 2+ , Cd 2+ , K + and Ca 2+ , and it was drastically inhibited by F − . The enzyme displayed high thermostability, retaining more than 90% activity at 60 °C during 120 h and displayed a t 1/2 of 94.5 h and 6.2 h at 70 °C and 80 °C, respectively. The enzyme demonstrated strong resistance toward pepsin and trypsin, and it retained more than 90% residual activity for both enzymes after 1 h treatment. Additionally, the enzyme efficiently hydrolyzed phytate in livestock feed, liberating 15.3 μmol phosphate/mL after 2.5 h of treatment.

Based on an observed decrease of effective thermal conductivity of milk during coagulation, a heated thermistor sensor was developed for monitoring curd formation. The thermistor was heated with a constant direct current, and its voltage was measured during milk coagulation, indicating a drop after the enzymatic reaction. The sensor was studied in the laboratory for different milk acidities, rennet concentrations, added calcium chloride, and coagulation temperatures. It was also tested in a commercial cheese plant for more than a month. The cutting time established by the cheesemaker in 16 experiments was compared with a prediction equation, and the standard error of prediction was 1.9 min.

Five lactating goats were used in a 5x5 Latin square experiment to determine the effects of feeding whole sugarcane (WSC) on intake, total tract nutrient digestibilities, milk yield and milk composition. Goats were fed diets containing 0, 100, 200, 300, and 400 g kg(-1) WSC and 400, 300, 200, 100, and 0 g kg(-1) tifton hay (TH). Intake of dry matter and neutral detergent fiber (NDF) decreased linearly (p<0.05) as the level of WSC in the diet increased. Total tract nutrient digestibilities were not influenced by WSC inclusion except for the digestibility of NDF which decreased linearly (p<0.05) as the level of WSC in the diet increased. Inclusion of WSC linearly (p<0.05) decreased milk yield without affecting milk composition. It was concluded that WSC had a lower feeding values than TH for lactating goats.

This work aimed to study the partition of cheese whey proteins alpha-lactoalbumin and beta-lactoglobulin using aqueous two-phase system by applying the cloud point extraction technique. The cloud point temperatures were determined under different concentrations of copolymer and salt. The system providing the best protein separation conditions was 20 mass% of copolymer PE61 and potassium phosphate salt solution of 100 mM, at pH 7. The protein alpha-lactoalbumin remained preferentially in the aqueous phase and the beta-lactoglobulin was transferred to the copolymer phase.

O Simpósio de Alimentos (SIMAL) e a Semana Acadêmica de Ciência e Tecnologia de Alimentos (SEACAL) são eventos organizados pelos professores e estudantes do curso de Ciência e Tecnologia de Alimentos da Universidade Federal de Viçosa, Campus Rio Paranaíba.

Análise de componentes da fruta-de-lobo (solanum lycocarpum st. Hil.) visando sua utilização na alimentação humana ou pela indústria de alimentos Analysis of components of wolf's fruit (solanum lycocarpum st. Hil.) classic its use in human nutrition or by the food industry

Soybean has good properties for industrial application, including tofu production. Cultivar is one of the major factors that influence food product making potential of soybeans. This study aimed to perform the physicochemical characterization of grains, tofu and okara, as well as the sensory analysis of tofu produced from seven different experimental lines of soybean. CAC TNS showed the lowest 100 grain mass, which was equal to 12.43 g. The protein content of the cultivars showed no significant difference, which ranged from 27.77 % to 36.82 %. For tofu yield, there was no significant difference between all cultivars. Tofu of CP-09, CP-27 and CAC TNS cultivars showed the highest protein concentration and were equal to 12.76 %, 11.58 % e 11.20 %, respectively. Tofu from CP-02, CP-09, CP-12, CAC TN and CAC TNS cultivars had the highest scores for the flavor parameter. However, only tofu from CAC TN and CAC TNS had higher scores for the aroma parameter. Regarding the texture, the tofu from CP-09, CAC TN and CAC TNS showed the highest scores. Thus, CAC TNS cultivar is the most suitable to produce tofu for providing a product with better sensorial acceptance and high nutritional value. The okara obtained from the different cultivars showed considerable amounts of proteins, lipids, minerals and carbohydrates, constituting a potential residue for human consumption. These results could be used as auxiliary guide of tofu manufacturers during raw material selection with characteristics more acceptable by consumers.

Alternativas para o processamento de leitelho são importantes para as indústrias e para a redução da poluição ambiental. Esse estudo avaliou o efeito da substituição de leite por leitelho no processamento e nas características do kefir. Dois tratamentos foram usados para produzir kefir, utilizando leite ou leitelho como matéria-prima. Os produtos foram avaliados em um período de 28 dias, onde o pH diminuiu de 6,0 até 4,0 e de 6,5 até 4,1 para os produtos fabricados com leite e leitelho, respectivamente. As contagens médias finais de leveduras e bactérias láticas foram 5 log UFC mL-1 e 8 log UFC mL-1, respectivamente. Coliformes não foram detectados. A aceitação sensorial do kefir produzido com leitelho foi similar à do produto produzido com leite.