Goat Breeds and Ricotta Cheese
In this section, we report a further example that can be considered a case study. Among products made from whey, Ricotta cheese is likely the earliest. It is considered as a high-moisture product, and it is essentially a co-precipitate of proteins with a mild flavour and soft texture.
Goat Ricotta Cheese
Whole goat whey cheese. It weighs 200–500 g and is consumed fresh; its shape is cylindrical, 11 cm in diameter and 8 cm high; there is no rind, the texture is compact but creamy, the paste is spreadable, eyeless and pure white coloured. Its odour is pleasantly lactic, no goaty; its taste is sweet, lactic, sapid and cloaking, slightly goaty.
This study was conducted under the same condition as for goat breed and Caciotta cheese case (see Sect. 3). The experimental flock was set-up with goats belonging to the Local (L), Girgentana (G), Red Syrian (R) and Maltese (M) goat breeds (Table 3). The flock management and feeding system are reported in the previous case (see Sect. 3) study.
Ricotta Cheesemaking, Sampling and Analysis of Milk and Cheese
Three Ricotta cheese-making trials for each breed were conducted. A simplified flowchart of cheese-making process is shown in Fig. 10. Thirty-six samples of whole milk, whey and Ricotta cheese were analysed for their chemical
Fig. 10 Flowchart of Ricotta cheese
composition, FA profile, textural properties and sensorial properties. The analytical methods and assessment procedure are previously reported (see Sect. 2.1).
Changes in milk, whey and Ricotta cheese of chemical composition, FA profile, textural properties and sensory profile were analysed by ANOVA procedure (Systat 7 1997). The statistical analysis evaluated the effect of Local, Girgentana, Maltese and Red Syrian breeds. Data about sensory profile were normalised before submitting them to ANOVA repeated measures procedure. Significance was declared at P < 0.05; differences between means were tested using Fisher's LSD test.
Results and Discussion
The average gross composition of milk, whey and Ricotta cheese for each breed is shown in Table 7. The breed effect was more evident in Ricotta cheese than in whey and milk.
The main effects of goat breed in Ricotta cheese were found in dry matter, fat and lactose contents. The milk produced by R breed showed higher fat content when compared to the M and L breeds. G milk exhibited intermediate values. As concern the whey fraction, G, R and L breed had a higher content of dry matter than M breed. Ricotta cheese from the Girgentana breed showed a higher dry matter and lactose content and an intermediate fat content than the same product from R and M breeds. The Ricotta cheese from Local breed exhibited an interesting chemical composition with high fat and dry matter content. Ricotta cheese did not reflect the milk gross composition in terms of fat and dry matter. According to Pintado and Malcata (1996), differences between milk and Ricotta cheese are related to heating time and heating temperature during Ricotta cheesemaking.
The FA profile of Ricotta cheese was significantly affected by breed (Fig. 11). The cheese made from Girgentana breed contained significantly lower SFA content than other breeds. Compared to the L breed, G, R and M breeds had a higher content of MUFA, because of the higher oleic acid level. A higher PUFA content was
Table 7 Effect of breed on pH and chemical composition of milk, whey and Ricotta cheese (Pizzillo et al. 2005)
Means within row with different superscripts differ at a, b, cP < 0.05
1G Girgentana; R Red Syrian; M Maltese; L Locale breeds; SEM standard error mean
2DM dry matter
Fig. 11 Effect of goat breed on fatty acid composition (% FAME) of Ricotta cheese (Pizzillo et al. 2005). a, b, cP < 0.05
detected in Ricotta cheese from Girgentana breed compared to others because of the higher linoleic and arachidonic acid levels. Indeed, Ricotta cheese from G showed a level of linoleic acid 2.4, 2.7 and 1.1 times higher than R, M and L breeds, respectively, while its arachidonic acid content was 6.4, 1.6 and 1.9 times higher than the others.
As reported in previous studies (Di Trana et al. 2006a, b; Impemba et al. 2005), the breed affected the Δ9-desaturase activity index (ratio C18:1/C18:0), G breed having higher index value followed by R, L and M breeds. The product:substrate ratio indicates increased enzyme activity in G breed. The high level of MUFA and PUFA present in Ricotta cheese from Girgentana goat could encourage the use of this breed.
In goat dairy products, taste plays an important role in consumer acceptance (Ribeiro and Ribeiro 2010). Within the textural and colour properties of Ricotta cheese, the adhesiveness only was affected by breed; Girgentana breed exhibited a significant higher adhesiveness than Local breed, while no differences were detected among the others. The lower value of adhesiveness, detected in Ricotta cheese made from whey of Local breed, may be due to the higher fat/protein ratio exhibited by this product (Roland et al. 1999). The sensory attributes are shown in Fig. 12. The breed affected some sensory properties of Ricotta cheese such as “softness”, “greasiness” and “granulosity”. Higher “softness” and “greasiness” and lower “granulosity” and “goat” attributes were found in cheese from G and L breeds than others.
In our case, the “goat” flavour scores of Ricotta cheese made from R and M milk may be related to the different ratio of lipolysis and/or different frequencies of the as1-casein locus alleles (see Sect. 3.3). Large differences in texture and taste among cheeses issued from milk of different breeds and/or within breed are linked to the genetic variant of as1-casein in goats (Coulon et al. 2004). The characteristic “goat”
Fig. 12 Effect of goat breed on sensory profile of Ricotta cheese (Pizzillo et al. 2005)
flavour of goat milk products originates from milk fat and from the rate of fat hydrolysis; moreover, Grosclaude et al. (1994) have emphasised on the genetic dependence (see Sect. 3.3) of the variation of goat flavour intensity.
The results indicate that sensory properties and FA composition of Ricotta cheese vary according to the goat breed. The higher MUFA and PUFA levels, found in Ricotta cheese made from whey of Girgentana goats, are beneficial to human nutrition. Moreover, the greater “softness” and the lower sensor scores for “granulosity” and “goat” odour exhibited by this product could satisfy consumer demand for a cheese with adequate sensory and nutritional properties. The peculiarities of the Girgentana breed may motivate the use of this breed, and they are a tool for amplifying the sustainable use.