What do you know about whipped cream?

   

Whipped cream as shown in figure is cream that can be produced after whipping by a whisk or mixer until it is light and fluffy. It is usually flavoured with vanilla and is sweetened to give flavour. According to Food Regulations 1985, Regulation 100, cream or raw cream shall be the fatty liquid prepared from milk by separating the milk constituents, through a separation process in such a manner to extract the milk fat content. Cream or raw cream shall contain not less than 35 per cent of milk fat and shall not contain ant added substance. Whipped cream contains at least 30% of fat as dairy creams with lower fat contents do not whip into a stable foam. 

          Whipped cream can be categorized into two different types which are imitation whipped cream and dairy whipped cream. Imitation whipped cream is vegetable fat based products while dairy whipped cream while dairy whipped cream use butterfat. Imitation whipping creams are less sensible to overwhipping and consequently more flexible in use compared to dairy whipped cream. These products are available as pasteurized product in small bottles, plastics cups or large cans and sometimes, tetra-pack type of packaging. Example of whipped creams are shown in figure below. Whipped cream is normally get from market and is normally store in refrigerator.

Liquid whipped creams (left) and aerosol whipped cream (right) in supermarket.

          Whipped cream contain cream made from cow’s milk fat (35.1%), and stabilizer E407 which is carrageenan. Besides, other chemicals such as monoglycerides, diglycerides, polysorbate 80 also being used to help the cream to whip easily and stay firm once it is whipped. According to United States Department of Agriculture (USDA), dairy and eggs products for cream, whipped, cream topping and pressurized have the following composition as listed in the table below.  Composition of EMBORG whipped cream in market are also shown in table below to compare with USDA database.

Comparison of the composition of USDA database of whipped cream and EMBORG whipped cream in market.

(Source: https://ndb.nal.usda.gov/ndb/foods/show/299330?fgcd=&manu=&lfacet=&format=&count=&max=25&offset=&sort=default&order=asc&qlookup=whipped+cream&ds=&qt=&qp=&qa=&qn=&q=&ing=) 

     Figures below show two different manufacturing processes for whipped cream. The main differences between these two production lines are homogenization, separation and aging process in which second method carry out homogenization after cooling while first method does not carry out homogenization. Whipping process is done after storage for second method. 

First type of processing line for whipped cream. (Walstra, P., et al., 2006) 

Second type of processing line for whipped cream.

(Source: http://dairy-technology.blogspot.my/2014/01/whipping-cream.html)      

Whipped cream normally contains vegetable fat, milk proteins, sweeteners, water and emulsifiers and stabilizers. The milk protein is often sodium caseinate as whey proteins tend to induce agglomeration in the liquid cream during storage. In manufacturing of whipped cream, milk supply is very important. Milk supply must be from clean source and of good quality to avoid any contamination. Milk undergoes high temperature short time (HTST) pasteurization at 72 ^oC for 15 s. Pasteurization is carried to kill pathogenic bacteria and reduce enzymatic activity to increase shelf life of whipped cream without damaging the cream organoleptic qualities. The higher the temperature and the longer the holding period for pasteurization, the lower the final viscosity.

Centrifugation or separation happens at 50 ^oC and form cream or skim milk. The higher the separation temperature, the lower the final viscosity. Thus, separation temperature should be reduced to obtain higher final viscosity. However, too low temperature (35 ^oC) can cause more damage to fat globules. Thickening agent such as gelatin or carrageenan is then added and standardization is carried out to obtain the expected fat content. Aging is carried out to develop the final viscosity of whipping cream. Pasteurization is carried out again at 85 ^oC for 30 min.

Sample is then cooled to 5 ^oC and then package it. At higher fat contents, higher cooling temperatures must be used to prevent the cream from clogging the cooling section due to rapidly increasing viscosity. The cooling rate of whipped cream does not affect viscosity when it is tempered at 40 ^oC as most milk fat crystals have melting points under 40 ^oC. Therefore, after tempering at this temperature, there were very few crystals in fat globules of cream. This may lead to re-crystallization of fat globules during cooling. As a result, the formation of large cluster that can increase the viscosity is restricted due to the lack of necessary fat crystals at the oil in water interface for partial-coalescence between fat globules. In addition, plate heat exchanger can be used in cooling process. Bottle filling of hot cream followed by cooling would be preferable although it is uneconomical.

The crystallization process for 40 % cream at 8 °C.

(Source: http://dairyprocessinghandbook.com/chapter/pasteurized-milk-products)

           Furthermore, homogenization process is also important to produce whipped cream and is normally carried out after cooling process. Homogenization improves stability of emulsion, enhance texture, viscosity, and taste of whipped cream besides ensure well mixed of ingredients. Fat globules and particles break down during homogenization to make a smooth and viscous texture. The shorter the whipping time, the larger the surface-mediated partial coalescence in cream.

            Whipping produces stable foam by enclosing air bubbles in network of fat. Slow beating of cream may cause churning of cream while vigorous beating results in high over-run and finally smooth foam. However, avoid prolonged whipping as it may cause churning and yield butter and butter milk. In whipping process, air must comprise 50 to 60% of the volume of cream, and the air bubbles are fully covered by fat globules and fat globule clumps. Besides, the clumped fat globules make a space-filling network throughout the plasma phase during whipping process. A firm, smooth, and relatively stable whipped cream will be produced if all this happen.

            Whipping effect can be produced in aerosol can without clumping of fat globules and beating. When gas pressure in the cans is released, the foam is formed but the foam produced is unstable. Addition of surfactants or presence of proteins are required to impart some degree of stability by protein. The whipped creams are stored at 4 ^oC to reduce risk of spoilage.Whipped cream is excellent energy booster, healthy treats, promotes healthy bones, reduces risk of kidney stones, treats stress, and natural immunity booster.

       In conclusion, to produce whipped cream, a series of steps are being carried out such as pasteurization, homogenization, cooling, centrifugation, whipping and others. Selecting proper treatment and process is important to extend the shelf-life of the emulsion for whipped cream.

References

1.United States Department of Agriculture, Agricultural Research Service, National Nutrient Database for Standard Reference Legacy Release (2018) [Online], [Accessed 18 April 2018]. Available from World Wide Web: https://ndb.nal.usda.gov/ndb/foods/show/299330?fgcd=&manu=&lfacet=&format=&count=&max=25&offset=&sort=default&order=asc&qlookup=whipped+cream&ds=&qt=&qp=&qa=&qn=&q=&ing

2.Walstra, P., Wouters, J. T., & Geurts, T. J. (2006). Dairy Science and Technology (Second ed.). New York: Taylor & Francis Group. P 447-458.

3.Whipping cream (2018) [Online], [Accessed 15 April 2018]. Available from World Wide Web: http://dairy-technology.blogspot.my/2014/01/whipping-cream.html