Effect of freezing on the rheological, chemical and colour properties of Serpa cheese

Abstract

The effect of freezing on the properties of a raw ewes'-milk semi-soft cheese (Serpa cheese) was studied using small amplitude oscillatory (SAOS) and texture measurements, colour and chemical parameters. The freezing was introduced at three different stages of the ripening process (28, 35 and 42 days), and the cheeses were maintained frozen for 12 months. Cheeses were submitted to a slow or fast freezing method, and to different storage temperatures: -10 and -20°C (three replicates for each set conditions). Chemical data showed that only the proteolysis indicators exhibited differences between frozen and non-frozen samples; frozen samples showed higher values of NPN than the non-frozen samples, indicating that the freezing process did not prevent the secondary proteolysis of cheese. Frozen samples showed a significantly (P<0·05) stronger structure than the non-frozen, as indicated by hardness. However, the differences between the frozen and non-frozen samples were not significantly for storage modulus (G' 1Hz) and loss tangent (tan δ 1Hz) (P>0·05). Freezing affected mainly colour parameters: frozen samples were more luminous, and more yellow-green. The results allowed us to conclude that the damages caused by freezing to cheese properties could be minimized if this type of storage is introduced at the end of ripening (42 d) using a freezing temperature of -20°C.

Textural and physico-chemical characteristics of white brined goat cheeses made from frozen milk and curd. The use of square I - distance statistics

“…During the period of frozen storage, the diameter of the crystal increases due to the ice re-crystallization. It makes the relocation of water at the lipid-casein interface after thawing more difficult and diminishes its lubricant effect, all leading to a harder cheese structure (Alvarenga et al, 2011;Diefes et al, 1993). The same mechanism might also be the explanation why frozen curds lose water upon thawing and have higher values of all textural attributes, as seen in Table 2.…”

Shelf-life of reduced-fat white chocolate fillings using iota-carrageenan

“…Experimental data were subjected to one-way ANOVA (pairwise comparison of means with Scheffé test) in order to find differences during storage time and with the concentration of hydrocolloid. Data was analyzed using a statistic software as in Alvarenga et al (2011).…”

Impact of olive oil usage on physical properties of chocolate fillings

“…The data was analyzed using Statistica 6.0 (Statsoft, Tulsa, USA). The principal component analysis (PCA) was carried in order to evaluate the importance of the use of olive oil in the production of the fillings (Alvarenga et al, 2011).…”