Food Chemistry

(Sean Pound) #1

536 10 Milk and Dairy Products


Table 10.34.Biogenic amines in cheese (mg/100 g)


Cheese Phenylethyl- Tyramine Tryptamine Histamine Putrescinea Cadaverineb
amine


Cheddar 0–30 6–112 0–0. 22 .4–140 0–100 0–88
Emmentaler 0–23. 43 .3–40 0–1. 30 .4–250 0–15 0–8
Gruyere 6 .4–9. 9 0–20 0. 52. 5
Parmesan 0 .4–2. 9 0–58
Provolone 1–20 2–20
Edamer 0–1. 3 0–0. 41 .4–6. 50 .5–9. 4
Gouda 0–110 3 .5–18 2–20 2. 5
Tilsiter 0–14. 8 0–78 0–7. 1 0–95. 3 0–31. 3 0–31. 8
Gorgonzola 0–75 0–430
Roquefort 2 .7–110 0–160 1–16. 81 .5–3. 37 .1–9. 3
Camembert 2–200 2 0–48 0 .7–3. 31 .2–3. 7
aButane-1,4-diamine
bPentane-1,5-diamine


fruits (cf. 18.1.4.2.1) and meat (cf. 12.3.5) are
important sources.


10.2.8.4 Processed Cheese


Processed (or melted) cheese is made from natur-
al, very hard grating or hard cheeses by shred-
ding and then heating the shreds to 75–95◦C
in the presence of 2–3% melting salts (lactate,
citrate, phosphate) and, when required, utilizing
other ingredients, such as milk powder, cream,
aromas, seasonings and vegetable and/or meat
products. The cheese can be spreadable or made
firm and cut as desired. The shelf life of pro-
cessed cheese is long due to thermal killing of
microflora.
The heating process is carried out batchwise by
steam injection in a double-walled pressure ves-
sel equipped with a mixer, usually under a slight
vacuum. Continuous processes are conducted in
double-walled cylinders with agitator shafts.


10.2.8.5 Imitation Cheese


Imitation cheese (analogue cheese) is mainly
found in North America. They are made of
protein (mostly milk protein), fat (mostly hard-
ened vegetable fat), water, and stabilizers by
using processed cheese technology. A typical
formulation is shown in Table 10.35.


Table 10.35.Typical formulation of imitation cheese
(Mozarella type)

Component Amount (%)

Water 51. 1
Ca/Na caseinate 26. 0
Vegetable oil (partially hydrogenated) 8. 0
Glucono-δ-lactone 2. 8
Salt 2. 0
Color and aroma substances

10.2.9 Casein, Caseinates, Coprecipitate

The production of casein, caseinates, and copre-
cipitate is shown schematically in Fig. 10.30.
Coagulation and separation of casein from milk
is possible by souring the milk by lactic acid
fermentation, or by adding acids such as HCl,
H 2 SO 4 , lactic acid or H 3 PO 4. Another way to
achieve coagulation is to add proteinase enzymes,
such as chymosin and pepsin. The acid coagula-
tion is achieved at 35–50◦C and pH 4.2–4.6(iso-
electric point of casein is pH 4.6–4.7). Casein
precipitates out as coarse grains and is usually
separated in sedimentation centrifuges, washed,
and dried (whirlwind drier). The enzymatic pro-
cess involves heating to 65◦C after precipitation
in whey.
Increasing the level of Ca^2 +ions (addition to
milk of 0.24% CaCl 2 ) causes casein and whey
proteins to coagulate when the temperature is
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