Tackling the future challenges of Organic Animal Husbandry - vTI

Abstract
RAHMANN G & GODINHO D (Ed.) (2012): Tackling the Future Challenges of Organic Animal Husbandry.
Proceedings of the 2 nd OAHC, Hamburg/Trenthorst, Germany, Sep 12-14, 2012
Differences between organic and conventional ewe’s milk cheese
during the ripening process
ISABEL REVILLA 1 , CARLOS PALACIOS 2 , ANA MARIA VIVAR QUINTANA 3
1 Area de Tecnología de Alimentos, Universidad de Salamanca, Spain,
eMail: irevilla@usal.es.
2 Area de Producción Animal. Universidad de Salamanca.
Facultad de Ciencias Agrarias y Ambientales.
Salamanca. Spain. Email: carlospalacios@usal.es
3 Area de Tecnología de Alimentos, Universidad de Salamanca, Spain,
eMail: avivar@usal.es
Previous studies have shown that fat macroelements in milk were unaffected by the change of production
system from conventional to organic however the fatty acid composition and microelements
are affected. Since sheep’s milk is used for the production of cheese and there are no references
about it, the aim of this work was to study the evolution of physico-chemical, colour and textural
characteristic of ewe’s milk cheese of two breeds during the ripening process and to determine the
influence of production system organic vs conventional on them. Results showed that freshly made
organic cheese had higher values of dry extract, fat acidity, hardness and yellow colour and lower
values of pH. At the end of the maturation these cheese maintained higher values of fat acidity and
were yellower and darker than conventional ones.
Key words: Ewe’s milk, cheese, quality, colour, texture, ripening.
Introduction
Differences between organic and conventional systems are based on the origin of the feed that the
animals have and their conditions of husbandry (Council Regulation (EC) No 834/2007). However,
there are other implicit factors as well as the productive system such as breed, seasonality and ripening
that may influence on dairy products and make difficult the differentiation between organic
and non organic product (Sundrum, 2001). Previous studies have shown that fat, protein and lactose
percentages in milk were unaffected by the change of production system from conventional to organic
(Bergamo et al., 2003, Revilla et al., 2009) although other studies found significant differences
in macroelements (Zervas et al., 2000; Vicini et al.,2008). The greatest differences between
non organic and organic systems have been found in the fat and fatty acids composition (Bergamo
et al., 2003, Collomb et al. 2008) since the composition of the fat in milk is fundamentally determined
by feeding of animals (Revilla et al., 2009). Thus, differences between non-organic and organic
milk have been found using macro and micro elements (Gabryszuk et al., 2008) but no references
have been found for cheese.
Sheep’s milk is used almost exclusively for the production of cheese, so the aim of this work was to
study the evolution of physico-chemical, colour and textural characteristic of ewe’s milk cheese of
two breeds (Castellana and Churra) during the ripening process and to determine the influence of
production system organic vs conventional on them.
Material and methodology
Bulk tank ewe’s milk from flocks of two local breeds (Castellana and Churra) and two production
systems (organic and conventional) all of them from the same geographical area (Zamora, Spain)
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