Teses de Mestrado ESA
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Browsing Teses de Mestrado ESA by advisor "Achour, Sami"
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- Arbutus unedo leaf extracts as potential preservatives for quark cheesePublication . Derbassi, Nabila Ben; Carocho, Márcio; Barros, Lillian; Achour, SamiThe plant kingdom is an endless source of molecules that can be applied in almost all realms of society. The food industry has profited from the use of plants and their derived materials for many decades. Recently, the food industry has been looking into plants to find different ways of either preserving, coloring or sweetening foods. These natural food additives have become a recent trend, and consumers are preferring them over synthetic and artificial food additives due to harmful effects related to their consumption. Thus, in this work, leaf extracts of Arbutus unedo L. obtained by dynamic maceration and ultrasound assisted extraction with prior optimization through response-surface methodology, were optimized to obtain the highest yields and incorporated in quark cheese, then analysed over 8 days. Both extracts showed antioxidant and antimicrobial activity with no toxicity towards cell lines at the maximum tested concentration, and while the maceration extract showed lower antioxidant activity, when incorporated in the cheeses it better inhibited the proliferation of bacteria. As expected from a food preservative, the nutritional, chemical and physical parameters were not drastically changed from the addition of the extracts although the ultrasound extract preserved cheese did preserve soluble sugars when compared to the other cheeses. Both extracts are excellent candidates to be added to quark cheese allowing its consumption for more than eight days after opening. The two natural extracts showed better results when compared to the widely used preservative, potassium sorbate, and thus, could be used as a cheese additive and its use is encouraged by the food industry.