Additives to Cheese milk
(1) Calcium Chloride is frequently added at a level of about 0.02% to aid coagulation and reduce amount of rennet required, especially if milk is set immediately after pasteurization. The role of calcium in milk coagulation will be discussed in Coagulation.
(2) Nitrates (sodium or potassium nitrate) be added at levels of about 200 ppm to Edam, Gouda, Swiss to inhibit growth of gas forming Clostridium tyrobutyricum.
(3) Annatto cheese color is added to some cheese to standardize seasonal changes in color or to create orange cheese such as Cheddar and Cheshire.
The following are some facts about annatto.
- Annatto is a carotenoid similar to -carotene and Vitamin A in structure, but it has no Vitamin A activity.
- Annatto color is red to yellow pigment but it usually appears as orange. The red constituent is more apparent with decreasing pH (6-4.8) changing the orange to pink while at pH < 4.8 the pink fades and becomes nearly white. This explains the phenomenon of 'acid-cut cheese'.
- Bleaching and pinking of annatto is also caused by oxidizing agents such as copper, iron, chlorine and light.
- Oxidation of annatto is also encouraged by heat, so annatto is an unsuitable colorant for process cheese
- Alternatives to annatto are:
- Beta-carotene which is too yellow and makes the cheese taste like carrots.
- Apo-8-carotenal which has the advantage that it is not lost in the whey.
Goats' and sheeps' milk are flat white in color because they lack -carotene. Cows' milk may be whitened to mimic goats' or sheeps' milk. Chlorophyll based products which mask the natural yellow colour can be used as whitening agents. Titanium dioxide is an effective whitening agent but is no longer a legal additive for cheese.
(5) Ripening Agents
A wide range of products are available to accelerate cheese ripening or to develop a broader flavour profile. Relative to traditional cheese varieties, several factors suggest the need for ripening supplements:
- Nontraditional cheese making methods
- Pasteurized or heat treat versus raw milk
- Cows' milk substituted for the milk of other species
- Traditional rennet pastes containing a wide range of enzymes including lipases and proteases have been replaced with purified extracts
- Cold storage and transport of milk severely alters natural milk micro flora
- Economic pressure to reduce ripening time
- Marketing pressure to standardize quality attributes
Lipases (lipolytic enzymes) are traditionally added to cows' milk to produce cheese such as Feta, Romano, Kefalotyri, and Parmesan which are traditionally made from goats' or sheeps' milk. That's because goats' and sheep's milk, especially goats' milk, have more natural lipase than cows' milk. Commercial lipases are commonly extracted from kid goats.
Mixtures of enzymes from various sources added to the milk to accelerate ripening of aged cheese such as Cheddar. These cocktails include both lipases and proteases, with a predominance of proteases for Cheddar. Bacterial enzyme extracts from lactic acid bacteria have also been used. Accelerated ripening is further discussed in Ripening and packaging.