Clarissa Reschke da Cunha

Efeito do fator de concentração do retentado na composição e proteólise de queijo minas frescal de baixo teor de gordura fabricado por ultrafiltração

The effect of milk concentration by ultrafiltration on the chemical composition and proteolysis of low fat Minas Frescal cheese during refrigerated storage was determined. Three batches of cheese were made in one day using milk concentrated by ultrafiltration at three different concentration factors (CF): 2:1, 3:1 and 4:1. Cheese making was replicated on a different day. Protein breakdown, as well as pH and titratable acidity changes, were monitored during cheese storage for 2, 10, 20 and 30 days. It was observed that pH decreased with time, while titratable acidity and protein breakdown increased. The different concentration factors tested did not significantly change cheese composition and proteolysis, which means that the inclusion of whey proteins did not inhibit rennet proteolytic activity as expected. This leads us to believe that potential advantages associated with the use of ultrafiltration retentates in cheesemaking were compensated by negative effects related to the high humidity level of low fat cheese made from ultrafiltration retentates. Consequently, the shelf-life of this typically Brazilian cheese was lower than that of cheese made by conventional procedures.

Efeito do uso de cultura adjunta (Lactobacillus helveticus) na proteólise, propriedades viscoelásticas e aceitação sensorial de queijo prato light

Proteolysis, viscoelastic properties and sensory acceptance of reduced fat Prato cheeses made with and without adjunt culture (AC) were evaluated. The cheeses were made from microfiltered milk. Two different treatments were replicated twice: control cheese was made only with traditional starter, while the other was made with the addition of both AC (Lactobacillus helveticus) and traditional starter. Cheese composition was determined after 5 days of manufacture. Proteolysis and rheological properties were evaluated after 5, 25 and 45 days. Viscoelastic parameters were obtained using relaxation tests. Cheese sensory properties were evaluated using acceptability tests. There was no statistical difference (p>0,05) in cheese composition. The proteolysis depth indexes were significantly higher (p 0.05) in viscoelastic parameters for cheeses made with and without AC. Sensory acceptability tests indicated significant difference (p<0.05) between samples for flavor, texture and global impression. Cheese made with AC was better graded than cheese made only with starter. Buying intention grades showed that 70% consumers would certainly or probably buy cheese made with AC, while only 43.4% would behave the same with control cheese.