Renata Golin Bueno Costa

Technological aspects of lactose-hydrolyzed milk powder

Few reports describe the effect of lactose hydrolysis on the properties of milk powder during production and storage. Hence, the aim of this study was to evaluate the effects of five different levels of enzymatic lactose hydrolysis during the production and storage of milk powder. As the lactose hydrolysis rate increased, adhesion to the drying chamber also increased, due to higher levels of particle agglomeration. Additionally, more brown powder was obtained when the lactose hydrolysis rate was increased, which in turn negatively affected rehydration ability. Using Raman spectroscopy, crystallization of the lactose residues in various samples was assessed over 6weeks of accelerated aging at a room temperature environment with 75.5% of air moisture. Products with 25% or greater lactose hydrolysis showed no signs of crystallization, in contrast to the non-hydrolyzed sample.

Efeito da nisina na contagem de Lactococcus e Lactobacillus em queijo Minas artesanal da região de Araxá - MG

The Minas artisanal cheeses from Araxa region are produced in Araxa, Campos Altos, Ibia, Pedrinopolis, Perdizes, Sacramento, Santa Juliana, Uberaba, Conquista, Pratinha e Tapira cities. These cheeses are made from raw milk and they are fairly handled, so they can carry pathogenic micro-organisms, from the milk itself and also from the hygienic and sanitary conditions to which they are subjected. Nisin can adjuvant to reduce the contamination of these cheeses, combined with good manufacturing practices to getting the milk and is a product easy to use. Nisin acts against Gram positive bacteria, some of which are pathogenic, such as Staphylococcus aureus. However, nisin can also inhibit the lactic acid bacteria, depending on the dose used in cheese manufacture and can consequently affect the desired sensory characteristics of the cheese artisan. Therefore, the objective of this study was to evaluate the effect of adding different concentrations of nisin on the behavior of two groups of lactic acid bacteria, Lactobacillus and Lactococcus , in Minas artisanal cheese from Araxa region, during the 60 days of ripening. The search result was satisfactory because it was found that nisin not interfere with the multiplication of Lactobacillus and Lactococcus along the cheese ripening of Minas artisanal from Araxa region

O DIÓXIDO DE CARBONO (CO2 ) E SEUS EFEITOS TECNOLÓGICOS NO LEITE E EM PRODUTOS LÁCTEOS

The Brazilian Federal Inspection Service prohibits the CO 2 addition to milk to cheesemaking and other dairy products. The justification against the addition of CO 2 is that the antimicrobiological effects reported in the current literature may generate negligence with regard to good manufacturing practices for milk and dairy products manufacturing. However, the main beneficial effects for various dairy products such as cheeses, are in terms of technological and economic aspects. These benefits generated by the use of CO 2 are sufficient to justify its applicability and encourage future research. As repor ted by dairies that worked with milk acidified by CO 2 injection to the cheese-making, only the savings with the reduction of coagulant use would be sufficient to ensure the return of investment in the injection system in just two and a half months . Therefore, it is believed, however, that the legislation on the CO 2 use can progress, particularly if there is interest by the dairy industry. The technological effects in milk caused by the use of CO 2 suggest the need for modification of the manufacturing process of some products to improve the benefits. Successful modifications are required to provide stimulation for the dairy industry to make the decision regarding to the use of this technology. This paper presents a review of the properties and effects of using CO 2 in milk and dairy products attempting to understand and increase the contribution of scientific knowledge about this technology by researchers and dairy companies in the Brazilian.

Use of coalho cheese whey in the pasteurized dairy drink elaboration

In Brazil, dairy drink is basically defined as the dairy product resulting from the mixing of milk and cheese whey. As they are economically viable, pasteurized dairy drink 1 Doutor em Ciencia e Tecnologia de Alimentos (UFV). Pesquisador e Professor da EPAMIG/ILCT. Rua Tenente Freitas, 116, Juiz de Fora, MG, Brasil. E-mail: junio@epamig.br. 2 Biomedico (UNIPAC). Campus VI Juiz de Fora. Av. Juiz de Fora, 1100, Granjas Betania. CEP 36047-362. Juiz de Fora, MG, Brasil. E-mail: felipealvesdealmeida@yahoo.com.br. 3 Doutor em Ciencia e Tecnologia de Alimentos (UFV). Pesquisador e Professor da UFMG. Montes Claros, MG, Brasil. E-mail: maxonze@yahoo.com.br. 4 Doutoranda em Ciencia e Tecnologia de Alimentos (UFV). Pesquisadora e Professora da EPAMIG/ILCT. Rua Tenente Freitas, 116, Juiz de Fora, MG, Brasil. E-mail: Vanessa.teodoro@epamig.br. 5 Doutora em Ciencia dos Alimentos (UFLA). Pesquisadora e Professora da EPAMIG/ILCT. Rua Tenente Freitas, 116, Juiz de Fora, MG, Brasil. E-mail: renata.costa@epamig.br. * Autor para correspondencia: EPAMIG/ILCT Rua Tenente Freitas, 116, Juiz de Fora, MG, Brasil. CEP: 36045-560 E-mail: junio@epamig.br. Recebido / Received: 22/12/2011 Aprovado / Approved: 07/05/2012 Pag. 14 Rev. Inst. Latic. “Cândido Tostes”, Jul/Ago, no 387, 67: 13-20, 2012

EFEITO DA ADIÇÃO DE TRANSGLUTAMINASE E GELATINA NA VISCOSIDADE DE BEBIDAS LÁCTEAS FERMENTADAS FABRICADAS COM SORO DE QUEIJO DE COALHO

Transglutaminase is an enzyme used in the food industry with the objective to produce molecules with high molecular weight by linking proteins, adding characteristics to the final product, such as increased viscosity. This study aimed to compare the viscosity of fermented dairy beverages without additives with the viscosity of dairy beverages added with transglutaminase, stabilizer (gelatin), and both ingredients. Fermented dairy beverages were made with 50% of “Coalho” type cheese whey in 4 treatments, these drinks were stored for 28 days at 7 oC and its viscosity was analyzed in duplicate weekly during this period. The experiment was performed in three replicates and the data were analyzed by Kruskal-Wallis and Tukey tests. It was observed that transglutaminase with glutathione had a similar effect to gelatin in the viscosity of dairy beverages produced under the conditions applied, exceeding the control treatment (without addition of enzyme and stabilizer), which makes this an interesting alternative technology for this type of product, with respect to viscosity increment. There was no significant effect of time on the viscosity of the samples.

MATURAÇÃO DO QUEIJO MINAS ARTESANAL DA MICRORREGIÃO CAMPO DAS VERTENTES E OS EFEITOS DOS PERÍODOS SECO E CHUVOSO

There is an expressive artisanal cheeses production in Brazil, manufactured from raw milk, and within this context, the state of Minas Gerais has a highlight in this activity with its five micro regions officially recognized. Within these, “Campo das Vertentes” was the last to have recognition. Evaluating the effect of dry and wet periods during the ripening of artisanal Minas cheese of the micro region above mentioned was the main objective of this study, which also related aspects of physicochemical composition of 10 to 30 days of ripening. Four registered dairies were selected and who attended legal requirements and good manufacturing practice to compose the experiment. The analysis of moisture content, moisture to the non fat substance (MNFS) and pH showed that these values varied greatly among cheeses and were highest in the dry season. Indexes of proteolysis behaved with variation between samples and advanced in the period of ripening, however, they were higher in the wet season. Even aware that the moisture content of the cheeses exerts strong influence on proteolysis, as well as other factors such as dosage of coagulant and “drop”, the room temperature observed in two periods of ripening was also very important for the advancement of proteolysis.

FORMAÇÃO DE BIOFILMES EM TROCADORES DE CALOR E SEUS EFEITOS EM LEITE E DERIVADOS

The inefficient surface cleaning of equipments such as heat exchangers results in the accumulation of mineral residue that can form fouling which are difficult to 1 Empresa de Pesquisa Agropecuaria de Minas Gerais, Instituto de Laticinios Cândido Tostes (EPAMIG/ ILCT). Rua Tenente de Freitas, 116, Santa Terezinha, 36560-000, Juiz de Fora, MG, Brasil. E-mail: elisangelamichele@epamig.br. 2 Universidade Federal de Vicosa (UFV), Departamento de Tecnologia de Alimentos, Vicosa, Minas Gerais, Brasil. * Autor para correspondencia Recebido / Received: 21/08/2013 Aprovado / Approved: 06/11/2013 54 MIGUEL, E. M. et al. Rev. Inst. Laticinios Cândido Tostes, Juiz de Fora, v. 69, n. 1, p 53-63, jan/fev., 2014 remove. It can represent one of the biggest problems for the equipment operation decreasing its efficiency and impairing the functioning which can either involve greater spending on chemicals to be carried out the cleaning process. Moreover, due to the presence of mineral in poorly sanitized surface, there may be the adhesion and biofilm formation by microorganisms which can compromises the quality and the shelf-life of milk and dairy products and can bring risks to the consumer health. This review aims to address relevant aspects of biofilm formation in heat exchangers surfaces, the process of fouling and its negative aspects for the dairy industry.