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J. Food Techno!. Vol. 311. No. 1, Pages 36-38 (January, 1975) Copyright :~ 1975. International Association of Milk, Food, and Environmental Sanitarians

Ultra- of Whipping

M. L. AGGARWALl Master, Inc. Lakeland, Florida 33802

(Received for publication June 19, 1974)

ABSTRACT COMPOSITION OF THE PRODUCT Downloaded from http://meridian.allenpress.com/jfp/article-pdf/38/1/36/2399837/0022-2747-38_1_36.pdf by guest on 02 October 2021 Ultra-pasteurization of whipping cream in the United States is now Initial composition of a product is very svnonymous with commercial sterilization. Correct composition of whipping cream is essential to comply with the standard of identity and important for its desirable performance in the to produce a product with desirable qualities. Careful selection of the consumer's hand. ultra-high-temperature (UHT) processing system is helpful to offset unwanted characteristics in the finished prodl'ct. Functionality of Fat various stabilizers and emulsifiers in the proauct is described. It was experimently established (2) that cream Homogenization of the product during UHT processing helps improve containing as low as 18o/o could be made to its physical stability. A long sheltlife whipping cream with improved whip. Nonetheless, the standard of identity requires a physico-chemical stability but containing no foreign additives can be produced commercially. Some of the physical conditions for whipping minimum of 30o/o milkfat in light whipping cream and cream such as its cold storage, whipping time, and temperature are 36 o/o milkfat in heavy whipping cream. Many processors necessary to assure consumers of its peak performance. of whipping cream !able this product as "cream for whipping." But there is no standard of identity for a product named "cream for whipping." It could, Americans are known throughout the world for their therefore, imply that any cream with a milkfat content of pragmatism. When commercially sterilized dairy 18o/o or more, and which is whippable, could be called products made their debut in the American market, cream for whipping! many regulatory agencies, dairy processors, and Protein distributors began debating about the heat treatment, A minimum of2.30o/oprotein was found (2) essential to shelflife, labeling, etc. of these products. More than achieve a good standability (stiffness in overrun) and anything else labeling was subjected to nationwide performance in a whipping cream. If, for instance, a light controversy until recently when the FDA, after much cream is prepared from freshly separated 30o/o milkfat deliberation, stipulated that all commercially sterilized cream it contains 2.50o/o protein and needs no protein milk products must be labeled as ultra-pasteurized. supplementation. On the other hand, if light or heavy Processors engaged in pasteurization of milk products cream is prepared from 36o/o or 40o/o milkfat cream the claim that whipping cream is the most troublesome product has to be fortified with protein because there is product. Regular pasteurized whipping cream is a only 2.0o/o protein in 40o/o milkfat cream and 2.20o/o in product that turns over slowly, and this results in a 36o/o milkfat cream. The protein content in whipping consistently excessive amount of returns. ln New York cream may be raised by addition of a calculated quantity city, for example, pasteurized whipping cream is of nonfat dry milk, , or fresh skim milk. required to be sold within 66 h after its production. New York City, for one, permits standardization of The significance of the ultra-pasteurization process for cream by addition of only fresh skim or whole milk. dairy processors, distributors, and consumers has been reported elsewhere (1). Application of ultra-pasteuriza­ Solids-not-fat (SNF) tion in the dairy industry has, by and large, extended the Protein content, however, is a part of the SNF but total shelflife of one of the most perishable milk products, i.e. SNF in whipping cream was found contributory to its whipping cream. Processing conditions for whipping final performance (2). A minimum SNF content of 6.25 o/o cream with extended shelflife are somewhat different is needed for optimum performance of whipping cream. from those of its regular analogue. Aggarwal (4) has Freshly separated 30o/o milkfat cream contains just discussed, in general, the fundamental requisites for enough SNF. Heavy cream made from 36o/o milkfat ultra-pasteurization of milk products. However, some of cream will need its SNF content raised by 0.50o/o. Cream the factors involved in the commercial application of with 40 o/o milkfat contains 5.35 o/o SNF. Therefore, the ultra-pasteurization to processing of whipping cream are SNF content in a light whipping cream must be increased outlined here. by l.Oo/o. The SNF content in whipping cream may be increased by addition of a calculated quantity of nonfat 'Present address: Ohio Processors, Inc,. London, Ohio 43140 dry milk, condensed milk, or fresh skim milk. Again, ULTRA-PASTEURIZATION OF WHIPPING CREAM 37

New York City is an example of a community which products depend on the kind of product, its composition, permits standardization of cream by addition of only its end usage, etc. fresh skim or whole milk. It may be pointed out here that Emulsifiers the SNF in whipping cream should not be raised with commercial grade lactose because an excessive lactose These are surface-active chemical compounds with a addition could delay development of the peak overrun in complex molecular structure. Their main function in an the product. is to prevent two immiscible liquids from separating. They are used in food products as such or in EQUIPMENT combination with stailizer. Since emulsifiers are both lipophilic (fat-loving) and hydrophilic (-loving) their type of ultra-high-temperature (UHT) processing T?e selection for application in the food industry depends eq mpment has much to do with the properties of finished upon the water:fat ratio in products. Performance of milk products. Whipping cream that is ultra-pasteurized emulsiflers is governed by water:fat solubility which is with a direct heat-exchange UHT system is more expressed by HLB (hydrophilic-lipophilic balance) Downloaded from http://meridian.allenpress.com/jfp/article-pdf/38/1/36/2399837/0022-2747-38_1_36.pdf by guest on 02 October 2021 susceptible to ''oiling off' than is its counterpart numbers ranging from 1 to 20. Thus, in a whipping processed with an indirect heat-exchange UHT system. cream containing 30 o/o milkfat the water: fat ratio is Hence, different types of equipment are designed for 70:30; when converted to the 20 point HLB scale this processing of different milk products. Since there are 14:6 ratio would be expressed as a HLB number of 14. several suppliers of equipment in this country one Therefore, any emulsitier which is about 60 to 70% (HLB frequently hears that a given UHT system is the best on 12 to 14) soluble in water can bring maximum emulsion the market. Some of the reasons given are: absence of stability in whipping cream with either 30 o/o or 36 o/o scaling of heating surface, better regeneration, high Mono- and diglycerides are the most common emulsiflers product velocities, longer operation, etc. This is not used in whipping cream. always true because the scaling problem is common to all UHT systems. However, in light of this, design engineers Stabilizers must attempt. first, to minimize the deposit and second, These are used mostly to control the behavior of water to accommodate it within the system. Regenerative in a variety of food products. Stabilizers are usually heating and cooling vary with the design of the UHT derivatives of natural products or products of animal system as reported earlier (3). There is no scientific origin. The hydrophilic and rheological properties of evidence that high velocities can avoid fouling-on the stabilizers are helpful in their selection for various dairy contrary very high product velocities provide conditions products. An emulsion stabilizer is necessary to improve for physical removal of scale with subsequent risk of . overrun, and degree of seepage, and to increase grittiness and sediment in the product. There is no large the stability of . Acidity or pH value of the capacity commercial UHT system yet available which product is of significant importance m the can operate efficiently and continuously for 12 h per day functionability of stabilizers. Sodium alginate in without an itermediate clean-up. conjunction with emulsifiers is the most common of all PROCESSING stabilizers used in whipping cream to provide long-term stability, flne particle size, and desirable rheology to the The quality of raw ingredients determines the quality product. Sodium alginate is not easily soluble in the cold of flnished ultra-pasteurized products. product, and so must be handled by trained plant l'vtixing of ingredients personnel and added to the product at the right A raw 40% milkfat cream, if used. should be stored temperature. is another stabilizer which below 40 F and must not be allowed to reach an acidity sometimes replaces and other times is combined with beyond 0.10% . It must be agitated slowly for a sodium alginate for use in whipping cream. The Bloom few minutes before pumping or drawing out of a holding value of gelatin has little or no effect on whipping tank. If ingredients are mixed between 80 and 130 F, properties of the flnished product. One of the main cream must be added last and a minimum holding time features distinguishing sodium alginate from gelatin is must be allowed. Longer holding of product mix at this that the latter drastically cuts down the amount of temperature could induce lipolysis and also could seepage in whipped cream during its subsequent storage. encourage growth of heat resistant bacterial spores. Gelatin may be added to the product at any temperature Longer holding of product mix at an elevated but must be allowed to imbibe some water before heating temperature also can impair the whipping quality of the otherwise it will not dissolve satisfactorily. flnished product. Stabilizers and emulsifiers must be Chemicals added at appropriate temperatures so they can dissolve satisfactorily to have adequate affinity with fat and The whippability of a whipping cream may be protein in the product. increased by hydrolyzing the ravv cream from which it is made. Hydrolysis of raw cream is caused by addition of Additives sodium or calcium hydroxide (food grade) so as to raise The type and amount of additives for use in dairy the pH of the cream to 9 .5-10.0. At this pH value 38 AGGARWAL

hydrolysis proceeds so far that an albuminous product to eliminate post ultra-pasteurization contamination. A with a good whipping capacity is produced. homogenization pressure to 150 psig is recommended for Because of recent advances in chemical technology an whipping cream, and a pressure above 200 psig could organic based chemical called triethanolamine has produce undersirable properties in the finished product. become available. It may be added instead of or together with alkaline compounds to produce dramatic UHT heat treatment improvement in whipping qualities of cream. Cream contains a somewhat larger number of Addition of the chemicals just discussed to whipping than milk from which it is separated. Since whipping cream is not widely practiced by the American dairy cream is one of the costlier milk products, a staggering processors. Local regulatory agenctes must be consulted loss could result if only slight carelessness is exercised in before resorting to application of additives in dairy its processing. It is, therefore, advisable, just to be on the products. safe side, to ultra-pasteurize whipping cream at a slightly higher temperature than that used for other milk Acidification products. Many UHT systems have two operating Downloaded from http://meridian.allenpress.com/jfp/article-pdf/38/1/36/2399837/0022-2747-38_1_36.pdf by guest on 02 October 2021 Acidity of cream may be raised quickly by addition of capacities, i.e. a system can process either 350 or 700 gal either commercial lactic acid or viscogen. In certain per hour. Whipping cream should always be processed areas, New York, for example, no additive whatsoever is with equipment operating at full capacity. At less than permitted in whipping cream. Therefore, these chemicals full capacity product velocity is greatly reduced and its to raise acidity would be construed as foreign additives in holding time at the final heating temperature is doubled. the cream. However, acidity of raw cream may be This slowdown of product in the UHT heating system increased by culturing it with lactic acid starter grown in could seriously affect product quality. The product must fresh skim milk to l.Oo/o acidity. A calculated quantity of be cooled to below 40 F before packaging. such a starter is added to raise the acidity in cream to at least 0.13 o/o lactic acid just before ultra-pasteurization of PERFORMANCE CONDITIONS FOR WHIPPING CREAM the product. The time-temperature combination employed in commercial ultra-pasteurization of whipping There are many phystcal conditions which could cause cream readily destroys the starter organisms. This slight an excellent whipping cream to fail in its expected peak increase in cream acidity before ultra-pasteurization performance if handled improperly by the customers. affects its and albumin. This chemical reaction Whipping cream, immediately after ultra-pasteurization, enables these proteins to form a gelatinous consistency possesses a slight cooked flavor and therefore, must be which is necessary to entrap air while the cream is being stored cold for 24 to 48 h to allow for the oxidation of whipped. More than 0.16o/o lactic acid could be sulfltydryl compounds that may have been produced detrimental to the physical stability during subsequent during the heat treatment. Any rise in temperature above longer cold storage of the product, and also could impart 40 F could not only cause churning of whipping cream a "culture-like" flavor to the whipped product. but also protein dehydration which results in poor air Homogenization entrapment during whipping of cream. To obtain Whipping cream is a with a high fat optimal results a cold whipping cream, after some content. An ultra-pasteurized whipping cream may be vigorous shaking, should be poured into a chilled bowl. It stored for weeks before it reaches consumers. should then be whipped with an electric hand mixer at Calcium-phosphocaseinate in the product could become the "whip" setting. A good whipping cream should come unstable because of gravity after long storage and forms to its maximum overrun within 1.5 min and if it fails to deposits at the bottom of a container which could cause do so in 3 min it should be considered as unsatisfactory. product separation. Homogenization of whipping cream during its UHT processing seems necessary to preserve REFERENCES physical stability, and to reduce significantly product 1. Aggarwal, M. L. 1971. . Its significance for separation during long storage. Homogenization before processors, distributors and conwmers. Southern Dairy Products J. final UHT processing requires a higher pressure to avoid 89(3):23, 49. product separation but higher pressure could affect 2. Aggarwal, M. L. 1972. Unpublished data. 3. Aggarwal, M. L. 1973. Computes efficiency of regenerative heat whipping qualities. Better results are achieved by transfer. Food Eng. 45(4):83. homogenizing after final UHT heat treatment. This 4. Aggarwal, M. L. 1974. Commercial sterilization and aseptic pack­ requires an aseptic homogenizer or homogenizing valve aging of milk products. J. Milk Food Techno!. 37:250-254.