Milk-and-Dairy-Products-in-Human-Nutrition-FAO

Chapter 3 – Milk and dairy product composition 83
folate content of these cheeses are of nutritional importance given the lack of this
compound in raw goat milk. B vitamins may either be produced by yeasts (mainly
Saccharomyces species) or lactic acid bacteria, the amount depending on bacterial
strains (Raynal-Ljutovac et al., 2008) and manufacturing procedures (Wigertz,
Svensson and Jägerstad, 1997). For instance, in yoghurts, Streptococcus thermophilus
and Lactobacillus acidophilus produce folic acid whereas Lactobacillus bulgaricus
consume it (Forssen et al., 2000, cited in Raynal-Ljutovac et al., 2008). The authors
note that “as the type of ripening strains and ripening parameters (e.g. temperature/
time) may differ between each class of products, it may induce variations in B vitamin
contents and especially high folate content for raw milk ripened lactic cheeses”.
Vitamin data are scarce for sheep milk cheeses (Raynal-Ljutovac et al., 2008).
Whey contains up to 94 percent of the lactose, much of which is lost in cheesemaking.
The remaining lactose is partially transformed into L-lactate or D-lactate
(Trujilllo et al., 1999, cited in Raynal-Ljutovac et al., 2008), or into glucose and
galactose on cheese-making. These residual carbohydrates found in fresh cheeses
disappear with increasing ripening time (Raynal-Ljutovac et al., 2008). Lactose
content in cheese is generally less than 1 g/100 g, with a few exceptions (Table 3.10).
Ricotta has a high lactose content as it is made from milk whey.
The curd contains almost 95 percent of the fat, and during cheese-making the
fat is concentrated between 6- and 12-fold, depending on cheese variety (Fox and
McSweeney, 2004). A study on goat and sheep milks and cheeses obtained from
French dairies or farms found no significant differences between the FA profile of the
milks and those of the full cream cheeses Roquefort (an uncooked blue-veined hard
cheese made from sheep milk) and Ossau-Iraty (pressed cheese made from sheep
milk), which indicated that the FA profiles of these cheeses were directly related
to those of the parent milks (Raynal-Ljutovac et al., 2008). Given this relationship
between milk and FA profiles, goat and sheep cheeses contain higher levels of shortand
medium-chain FAs than do cow milk cheeses (Raynal-Ljutovac et al., 2008).
The average CLA content in cheese is reported to be 0.5–1.7 g/100 g of total FAs
(Henning et al., 2006). The CLA content in sheep cheeses has been reported to be
higher than that of cow or goat milk cheeses (Prandini, Sigolo and Piva, 2011), with
average values of 0.6, 0.7 and 1.0 g of CLA/100 g total FA in cow, goat and sheep
cheeses, respectively. A review on the influence of processing on CLA content
in dairy products concluded that no changes in the CLA content occurs during
manufacturing or ripening of cheese (Bisig et al., 2007). A similar conclusion was
reached by Prandini, Sigolo and Piva (2011). Although the content of nutritionally
interesting FAs such as CLA can be increased by lipid supplementation of the goat
diet, this may be accompanied by a change in cheese flavour (Chilliard and Ferlay,
2004, Chilliard et al., 2005 and Chilliard et al., 2006a, cited in Raynal-Ljutovac et
al., 2008).
A similar result was reported for the trans-FA content in Emmental cheeses
made from milk produced by cows on three different diets (Briard-Bion et al.,
2008). The trans-FA content varied from 4–10 g/100 g total fat depending on the
diet, and was not significantly different (P < 0.05) from those in the parent milks.
Therefore, neither the thermal and mechanical treatments applied during processing
nor the enzymatic and chemical reactions occurring during ripening had any effect
on the trans-FA content.