Afonso de Liguori Oliveira

Addition effects of bovine blood globin and sodium caseinate on the quality characteristics of raw and cooked ham pâté.

The incorporation of 3% globin bovine extracted by the acidified acetone (AG) and carboxymethylcellulose (CG) methods as replacer for sodium caseinate (CA) in ham pâté was evaluated. The raw pâté batter was evaluated for salt-soluble protein content (SSP), water holding capacity (WHC) and raw batter stability (RBS). The results of CG were similar to those of CA, having both improved two of the three paramaters studied, and AG was the most deleterious, having decreased SSP, WHC and RBS. Only the AG incorporation had unfavorable effects on the cooked ham pâté, decreasing the pH and increasing the thiobarbituric acid reactive substances (TBARS) over the storage period (0-45 days). The results suggest CG as the best replacer for CA as the emulsifying agent for ham pâté.

Enumeração de Campylobacter spp. e presença de Campylobacter jejuni em carcaças de frango no estado de Minas Gerais

Campilobacteriose e uma zoonose de distribuicao mundial, com repercussoes importantes na saude publica e um grande impacto socioeconomico. As rotas de transmissao ao homem das especies de Campylobacter sao o contato direto com animais portadores, agua ou alimentos contaminados e e mais comumente associado ao consumo de carne de frango. O objetivo deste estudo foi detectar e enumerar Campylobacter spp. por um metodo rapido (SimPlate®) e pelo metodo convencional (plaqueamento direto em agar mCCD), determinando a frequencia e o nivel de contaminacao em 75 amostras de carcacas de frangos (25 Pre-chiller e 25 Pos-chiller obtidos em abatedouros sob inspecao federal no Estado de Minas Gerais e 25 amostras congeladas, coletadas no comercio verejista). As amostras avaliadas, independentemente do metodo utilizado, apresentaram Campylobacter spp. em 56,0% das carcacas antes do chiller e 44,0% apos o chiller. A contagem das amostras congeladas se apresentou abaixo do limite de deteccao do metodo. Das 75 amostras testadas, 34,7% foram positivas para Campylobacter spp. Das amostras positivas, 38,5% foram identificadas como C. jejuni e, entre estas, o maior numero de C. jejuni foi obtido nas carcacas de frango antes do chiller (42,9%), seguido de carcaca de frango apos o chiller (36,4%). O estudo mostrou que a deteccao e enumeracao e variavel, embora em nenhuma das amostras destinadas ao comercio foram obtidas contagens acima da dose infectante estabelecida. O uso do SimPlate® foi adequado e equivalente ao plaqueamento direto em agar mCCD e apresentou uma melhor taxa de recuperacao de celulas de Campylobacter spp.

Yeasts and hygienic-sanitary microbial indicators in water buffalo mozzarella produced and commercialized in Minas Gerais, Brazil

The aim of this work was to study the yeast populations and the main hygienic-sanitary microbial indicators in water buffalo mozzarella produced and commercialized in Minas Gerais, Brazil. Forty-two water buffalo mozzarella samples were purchased from retail outlets in Belo Horizonte. In addition, five samples of consecutive starter cultures, curd before acidification, acidified curd and mozzarella were collected at an industry in the city of Oliveira. Only three of the five water samples analyzed were suitable for consumption according to Brazilian sanitary standards. Four milk samples were highly contaminated with fecal coliforms, and did not meet the minimal hygienic-sanitary standards according to Brazilian regulations. Only one sample of buffalo muzzarela purchased from retail outlets exceeded the limit for coagulase-positive Staphylococcus. Eleven samples showed counts of thermotolerant coliforms higher than 5 × 103 CFU.g−1, but still lower than the maximum permitted by the Brazilian laws. Salmonella spp. and Listeria monocytogenes were not isolated. Debaryomyces hansenii, Candida lusitaniae and C. parapsilosis were the prevalent yeast species isolated from cheese. Among samples from the production stages, the acidified curd presented the highest numbers of yeasts, with C. catenulata being the most frequent species isolated. Some opportunistic yeast species such as C. guilliermondii, C. tropicalis, C. parapsilosis, C. lusitaniae, C. catenulata, C. rugosa and C. krusei occurred in the mozzarella cheese samples analyzed. The mozzarella cheese presented a low microbial load as compared to other cheese already studied, and the yeast biota included species typical of cheese and also opportunistic pathogens.

Avaliação da estabilidade e da qualidade do patê de presunto, adicionado de globina bovina e de caseinato de sódio, como agente emulsionante

This study evaluated the effect of the use of bovine globin extracted by acidified acetone method (GT), bovine globin extracted by carboxymethyl cellulose method (GCMC) and sodium caseinate (CA) on the chemical composition and on microbiological and sensorial qualities of the ham pate. Also, the stability of this meat product was studied during the storage for 45 days under refrigeration, on the pH and on the lipid oxidation measurements. An increase of the protein contents was observed in all samples. Moreover, only the incorporation of GT produced a significant decrease of pH and an increasing of thiobarbiuric acid reactive substances (TBARS) values during storage. No microbial effects were observed while some significant differences were observed between PCA and PGCMC added pates.

Caracterização química e funcional do caseinato de sódio e da globina bovina

With the aim of finding an industrial utilization for proteins from bovine blood, two methodologies for globin extraction were tested. Also, the chemical composition of this protein and the effect of the addition of NaCl on some functional properties were evaluated. The results were compared to those obtained for commercial sodium caseinate. The extraction method using acidified acetone showed a better yield and protein recuperation when compared to the carboxymethyl cellulose method. However, the former is not recommended for food use, due to the presence of organic solvent residues in the protein. Moreover, the extraction procedure influenced the chemical composition of bovine globin. The addition of NaCl produced varied effects on the functional properties of the studied proteins like a reduction of the solubility, emulsifying capacity (EC) and emulsifying activity index (EAI), which was higher for a salt concentration close to that used in meat products (0.25mol/L). In the case of sodium caseinate this level of salt had a negative effect on all functional properties studied, except the ES. The use of a 10 fold lower NaCl concentration improved both EAI and ES.