Izvorni znanstveni članak
The Effect of Long-term Freezing on Renneting Properties of Sarda Sheep Milk
Michele Pazzola
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Maria Luisa Dettori
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Gianpiera Piras
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Emanuela Pira
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Fabio Manca
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Ornella Puggioni
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Antonia Noce
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Giuseppe Massimo Vacca
; Department of Veterinary Medicine, University of Sassari, via Vienna 2, 07100 Sassari, Italy
Sažetak
Cold storage is a well-known strategy to limit concerns about seasonality for sheep dairy productions. The aim of this study was to investigate the effect of long-term freezing on milk renneting properties from the Sarda sheep, an autochthonous breed from Italy. Two-hundred milk samples from 50 pluriparous Sarda ewes were collected at monthly intervals throughout the lactation from April to July. Each sample of fresh milk was analysed for composition and subsamples were obtained and frozen for one, three and five months. Renneting properties, both from the fresh and frozen subsamples, were achieved using the Formagraph instrument and results were submitted to a mixed model statistical analysis. The storage effect significantly affected (P<0.01) the renneting parameters. A large amount of non coagulating subsamples was registered after a long-term frozen storage. Furthermore, milk clotting time was longer in frozen subsamples and curd firmness diminished after a freezing period of five months. In conclusion, the remarkable decreasing of sheep milk renneting characteristics after frozen storage can predict a worse yield and quality of cheese-making and suggests that freezing of Sarda raw milk should be limited to shorter periods.
Ključne riječi
sheep; milk; renneting properties; freezing
Hrčak ID:
106922
URI
Datum izdavanja:
4.9.2013.
Posjeta: 1.070 *