Isolation of high quality DNA: a protocol combining “rennet” and glass milk

High quality DNA is essential for many molecular biology techniques. However, the reagents used for that purpose usually are expensive and/or cause a high environmental impact. Here, we describe two alternative protocols that use inexpensive reagents and are not hazardous to the environment. The first protocol utilizes the enzyme chymosin, normally used as “rennet” in cheese production and which is easily obtained on the commercial market. The second protocol uses “rennet DNA extraction protocol” combined with the DNA binding capacity of glass powder (glass milk), which can easily be “home made”. The first protocol is used when a high yield of DNA is needed, whereas the second protocol is used for production of a higher quality DNA, being able to work with sparse samples.

Análise de rentabilidade de uma empresa com opção de comercialização de queijo ou leite / Analysis of profitability in a production system with the option of commercializing cheese or milk

Por meio de simulações, compararam-se os dados de rentabilidade do sistema de produção de uma propriedade rural localizada em Nepomuceno, MG, considerando duas situações: a primeira, real, produz queijo, e a segunda, simulada, vende leite para o laticínio. A produção e a comercialização de queijo mostraram-se mais rentáveis que a comercialização do leite in natura, representando uma alternativa para o incremento da renda do produtor de leite.

It was performed a simulation in order to compare the profitability of a cheese producer dairy farm, located in Nepomuceno city, Minas Gerais state. According to the simulation, data of the production system were compared in two different situations: cheese production (real) and selling milk to dairy. The cheese production and marketing was more profitable than milk selling, representing an alternative to increase the productorÆs income.

Responses to selection for milk traits in dairy buffaloes

The aim of the present study was to estimate the index and individual responses to selection for milk (MY), fat (FY) and protein (PY) yields for different breeding goals for two commercial buffalo milk production systems in São Paulo State characterized by: 1) all milk produced is sold to the industry (MILK) and 2) all milk produced is used in the mozzarella cheese-making process at the farm (MOZZARELLA). The current payment policy is based exclusively on milk volume. The mozzarella price refers to the wholesale selling price. Index responses to selection (IR) were calculated for three different breeding goals (BG): 1) MY exclusively (BG(1)); 2) FY + PY (BG(2)) and 3) MY + FY + PY (BG(3)). IR for the MILK system were 41.79 US dollars (BG(1)), 5.91 US dollars (BG(2)) and 38.22 US dollars (BG(3)). For the MOZZARELLA system, IR were 179.50 US dollars (BG(1)), 262.85 US dollars (BG(2)) and 402.41 US dollars (BG(3)). The results suggest that for the present circumstances, selection for milk components is not advantageous when milk is produced for sale to the industry. However, when mozzarella making is added to the system, the selection for components and milk volume is the most economically beneficial.

Sistemas de embalagem para queijos / Packaging systems for cheese

Nesta revisäo säo primeiramente levantados os problemas envolvidos na conservaçäo de queijos que podem ser retardados ou minimizados por uma embalagem com consequente aumento na vida útil. Conhecendo-se as características dos materiais e sistemas de embalagem utilizados, é entäo avaliado até que ponto preenchem os requisitos de proteçäo exigidos pelos diferentes tipos de queijo e, quando possível, säo apontados novas alternativas e sistemas de embalagem com melhor desempenho