Cottage Cheese by Ultrafiltration

Cottage Cheese by Ultrafiltration

Cottage Cheese by Ultrafiltration H. R. COVACEVICH 1 and F. V. KOSIKOWSKI Department of Food Science Cornell University Ithaca, New York 14853 ABSTRA...

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Cottage Cheese by Ultrafiltration H. R. COVACEVICH 1 and F. V. KOSIKOWSKI Department of Food Science Cornell University Ithaca, New York 14853

ABSTRACT

ceptance in the manufacture of unripened soft cheese in France, but the principle has not been tested for Cottage cheese. Earlier feasibility studies on Cottage cheese manufacture from retentates by Mattews et al. ( 1 1 ) w e r e limited to 1:2 concentrates with only 6.2% protein. Recently Covacevich and Kosikowski ( 3 ) h a v e reported making Cream cheese from high protein retentates. Cottage cheese results from an acid precipitated curd, is mildly acid, and has a meaty consistency. Its basic manufacture, which has not changed radically since its inception, is reported by Collins (1), Emmons (4,5), Kosikowski (6), Thurston and Gould (12), and Van Slyke and Price (14). The objective was to appraise the potential for making Cottage cheese from skim milk retentates concentrated to the normal protein percent of such cheese, approximately 15%.

Cottage cheese making by direct ultrafiltration with retentates of maximum p r o t e i n concentration (15%) was explored. Other uhrafihration forms applied included single and double diafiltration and simultaneous fermentation with or without diafiltration. The flavor of Cottage cheese made from single layer cooked retentates obtained by diafiltration with simultaneous fermentation approached those conventionally manufactured, but the curd, though uniformly smooth, displayed a gelatin-like quality and minimum cream dressing absorption. Cottage cheese from the retentates of high protein concentration displayed cons i s t e n t l y lower scores for color and general appearance. Making ultrafihrated curds into whipped cream Cottage cheese improved color and appearance. Internal heating of direct acidified and lactic acid fermented retentate curds as s i n g l e l a y e r s w i t h direct steam at atmospheric pressure was rapid; less than 5 s exposure achieved a uniformly cooked body. The future success of making Cottage cheese from skim milk retentates, concentrated 1:5, is dependent upon solving problems of cooking curds and developing proper texture and cream absorption.

MATERIALS AND METHODS Cottage Cheese Manufacture by Culturing.

Lactobacillus bulgaricus, Streptococcus cremoris and a commercial lactic acid starter

INTRODUCTION

The production of highly concentrated milk retentates (1:5 or 1:6) by ultrafiltration and the direct application of such retentates to cheesemaking was suggested by Maubois and Mocquot (8,10). Uhrafiltration has found ac-

Received April 7, 1977. Associate Director, FAO Regional Dairy Training and Development Centre for Latin America, Providencia 871, 2°, Piso, Casilla 10095, Santiago, Chile. 1978 J Dairy Sci 61:529-535

were used in various Cottage cheese making experiments which involved uhrafihration and fermentation of the skim milk to pH 4.6 (Table 1). The pH was measured with a glass electrode potentiometer (Beckman Expandomatic). Standardized retentates ( 2 0 % total solids) were inoculated with 5% of S. cremoris and commercial lactic acid starter or 5% of L. bulgaricus and incubated at 32 C and 37 C, respectively. A small amount of single-strength rennet was introduced with the starters. Flat pans containing a single layer of curd at pH 4.6 were stored at 5 C for 1 h before cutting. The curd layer was cut into 6.5 mm cubes and placed on flat Wilson hoop lids lined with aluminum foil with sides 1.25 cm high. The lids were placed immediately in a preheated direct steam chest for various periods or were heated in water at 51.5 C. The thermocouples and recording potentiometer used to register the

529

tall

o

o t~

T A B L E 1. M a n u f a c t u r i n g c h a r a c t e r i s t i c s of C o t t a g e cheese o b t a i n e d b y c u l t u r i n g s k i m m i l k r e t e n t a t e s .

E

Experiment no.

o

Z

1

~o -.1 co

2

o

3 4 5

6

Treatment no.

Retentate characteristic a

1 2 3 4c 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Conventional Direct UF Direct U F D i r e c t UF D i r e c t UF Direct UF Direct UF F e r m + UF Ferm + UF F e r m + Diafil. F e r m + Diafil. F e r m + Diafil. F e r m + Diafil. F e r m + Diafil. F e r m + Diafil. Ferrn + Diafil. F e r m + Diafil. F e r m + Diafil.

Starter b

Rennet rnl/ 4.54 kg

p H at end of fermentation

. . . M Lb M Sc Sc M Sc M Sc Sc Sc Sc Sc Sc Sc Sc Sc

11.25 11.25 11.25 7.50 7.50 7.50 5.63 5.63 1.00 1.00 .50 .50 .50 .50 .50 .50 .50

5.0 5.4 4.7 5.0 4.9 4.9 4.9 4.9 4.9 4.9 4,7 4.7 4.7 4.7 4.7 4.7 4.7

Fermentation time hours

. . . ., . 3.75 5.75 6.75 6.50 6.50 8.00 8.00 11,00 11.00 11.00 11.00 11.00 11.00 11.00

Heating time s

5 5 5 10 10 i0 15 15 15 15 (60) d (600) d 15 15 (600) d (1200) d (2400) d

Cooling time s

10 10 10 30 30 30 60 60 60 1800 (1200) e 1200 (1200) e 1200 1200 1200 1200

a D i r e c t UF, d i r e c t u l t r a f i l t r a t i o n ; F e r m + UF, s i m u l t a n e o u s f e r m e n t a t i o n in u l t r a f i l t r a t i o n ; F e r m + Diafil., d i a f i l t r a t i o n a n d f e r m e n t a t i o n . bM, c o m m e r c i a l lactic acid s t a r t e r ; Lb, L. bulgaricus; Sc, S. cremoris. CStarter was a d d e d in the c r e a m dressing a n d n o t in t h e r e t e n t a t e . d H e a t e d in w a t e r at 51.5 C. e c o o l i n g w a t e r a d j u s t e d to p H 8, in t h e first 10 rain wash, all 12OO s c o o l i n g t i m e s were u s e d as t w o s e p a r a t e w a s h i n g t i m e s of 6 0 0 s each. f R e c o v e r y = ( u l t r a f i l t r a t e d c o t t a g e cheese c u r d w e i g h t / o r i g l n a l r e t e n t a t e w e i g h t ) X 100.

Recovery of cottage c h e e s e %f

94190 77.40 76.10 73.30 78.90 95.61 98.90 91.89 90.30 101.94 104.13

79.70 73.38 76.54

O < > <

X O © ct~

COTTAGE CHEESE BY ULTRAFILTRATION temperatures had a response time less than 2 s. The heated cubes were cooled rapidly to 5 C in chilled water, acidified (pH 6.0) and chlorinated (5 ppm). The cooled cubes were drained a n d stored in weighed plastic containers. Recovery of curd weight was calculated. H o m o g e n i z e d ( L o g e m a n Homogenizer, Model A-40) creaming mixtures were prepared according to Kosikowski (6) and used in Experiments I and 2 (Table 1). The creaming mixtures for Experiments 3 through 6 (Table 1) were formulated similarly but processed according to Manus (7). Locust bean gum was ~tdded as a stabilizer, and the mixture was pasteurized at 71 C for 30 rain. Homogenization (Cherry Burrel A 200 Homogenizer) was at 31 C and 284.9 kg/cm 2 single stage. Whipped cream Cottage cheese was made as described by Kosikowski (6).

beds were cut into uniform 6.5 m m cubes with wire cheese knife. A copper-constantan wire thermocouple with an exposed end 3 mm long and 1 m m in diameter was inserted in a cube, and cubes were introduced as single layers on pans into a hot, direct steam chest or into hot water at 51.5 C. Temperature changes against time were recorded [Honeywell Brown Electronic Model RY 153 x 89-CII-III-(16)] in the cubes. Readings were repeated six times. Moisture changes induced by steaming also were measured. Fifty grams of curds were placed in wire baskets (15.5 × 10.5 cm) lined on the bottom with a perforated aluminum foil sheet. The baskets were held in the direct steam chest for fixed times. Then the heated curds were cooled immediately in iced water for periods equivalent to the heat treatment. RESULTS

Sensory Evaluation of Cottage Cheese Cheese quality was evaluated by two experienced testers using the official American D a i r y Science Association score card for Cottage cheese with coded samples tasted at random. The organoleptic series was analyzed as a two-way factorial experiment for unbalanced data by the method of Searle (12).

531

Heat Penetration Rates of Ultrafiltrated Cottage Cheese Curds Internal heating of direct acidified curds with steam at atmospheric pressure was rapid. Less than 5 s were required to achieve a temperature increase equivalent to 40 C (Fig. 1). Heating gave cubes with meaty texture and no

Analysis

Moisture, pH, protein, lactose, ash and mineral elements were analyzed by standard methods outlined by Covacevich and Kosikowski (2,3). Samples were blended (Waring Blendor Model BC 15) in 474-ml Mason jars that were equipped with a blending blade in the lid and held at - 1 7 . 8 C until analyzed. Heat Penetration Experiments In a preliminary study to assess heat penetration effectiveness, Cottage cheese curds were produced by direct acidification of high solids retentates. The retentates were blended to 20% T.S. (total solids) in a Hobart mixer (Model A-200) by adding permeate. Then 3.5% of glucono-6 lactone was introduced. The blender with a "J" blade was operated at speed 1. Retentates were spread (370 g portions) on Teflon coated pans 23.8 cm in diameter. The pans were held 6 h at 32 C and then chilled for 60 min. The resulting flat, single-layer curd

70 ¸ 60

50-

~o. i

302010.

5

10 SECONOS

15

20

FIG. 1. Temperature changes at different steam heating times in the interior of Cottage cheese curds made from ultrafiltration retentates by direct acidification. Journal of Dairy Science Vol. 61, No. 5, 1978

532

COVACEVICH AND KOSIKOWSKI

FIG. 2. Cottage cheese made from ultrafiltration retentates by using lactic acid fermentation and cooking in monolayers.

color change. Some shattering occurred with curds coagulated before an optimum pH of 4.6, and extended heating in the steam chest produced a slight yellow color. Alternative heating of curds by immersion in hot water increased the temperature in the cube interior to 49 C in 32.2 -+ 2.5 s. To achieve curd characteristics similar to those produced by steam heating, it was necessary to extend the heating time in hot water for at least 10 rain. Heating and cooling of curds made with glucono-6-1actone induced first a slight shrinkage followed by a swelling of the curds, so the original shape was maintained (Fig. 2). Rapid cooling of the curds with 20% T.S. heated directly with steam reduced moisture losses to below 1% (Fig 3). C o t t a g e Cheese f r o m C u l t u r e d a n d / o r Renneted

Retentates

Various modifications of manufacture are shown in Tables 1 and 2. All the curds were cooked as single layers. Exposure times in the steam chest were 10 to 15 s because a cooling effect occurred when the steam chest was opened to introduce the curds, and the temperature dropped to 85 C and then rose to 95 C. After cutting, heating, and cooking of curds made with the highest rennet level (11.25 m l / 4 5 0 kg rententate), Treatment 4, the moisture content remained constant (Table 2). Journal of Dairy Science Vol. 61, No. 5, 1978

Curds subjected to full rennet addition, Treatments 2 and 3, at pH 5.0 and 5.4 showed less moisture retention. Excess moisture in cheese was controlled by decreasing rennet to .5 ml/450 kg of retentate and by extending the cooling periods. The pre-cheese ultrafiltered mix for cottage cheese made from skim milk by diafiltration and simultaneous fermentation and cultured with Streptococcus cremoris (Experiment 4, i

7-

.

ut cooling

6-

5-

s

2-

nO

1

I

I

I

I

I

I

.5

1.0

1.5

2.0

2.5

3.0

MINUTES

FIG. 3. Water lost at different steam heating times in Cottage cheese curd made from ultrafiltration retentates by direct acidification.

COTTAGE CHEESE BY ULTRAFILTRATION

533

TABLE 2. Effect of manufacturing modifications on moisture of Cottage cheese obtained by culturing retentates• Total solids Treatment no. from Table 1

Precheese mix

Before cutting

After cutting

4 2--3 12 13 14 15 16 17 18

20.2 20.2 20.3 20.3 20.3 20.3 20.3 20.3 20.3

19.9 22.0 . . . . . . . . . . . . . . . . . . . . .

20.2 23.0

After heating and cooling

Total solids after creaming

19.6 23.2

... ...

(%)

. . . . . . .

T a b l e 1) h a d a l o w e r lactose c o n t e n t a n d a higher p r o t e i n a n d m i n e r a l c o n c e n t r a t i o n t h a n a c o m m e r c i a l C o t t a g e cheese (Table 3). Ultrafiltered pre-cheese mixes a n d finished C o t t a g e cheeses p r o d u c e d b y u l t r a f i l t r a t i o n were h i g h e r in clacium a n d p h o s p h o r u s a n d l o w e r in s o d i u m t h a n c o n v e n t i o n a l C o t t a g e cheese (Table 4). C o m p a r i s o n of LDS a n d t r e a t m e n t m e a n s i n d i c a t e d t h a t flavor a n d b o d y of t h e cheeses made by diafiltration and simultaneous ferment a t i o n a n d c o o k e d as single layers ( T r e a t m e n t s 10 t h r o u g h 18, T a b l e 1) a p p r o a c h e d t h o s e of c o n v e n t i o n a l cheese m a n u f a c t u r e d , Figure 4. C o t t a g e cheese f r o m r e t e n t a t e s h a d c o n s i s t e n t l y l o w e r (P = .05) color a n d general a p p e a r a n c e scores t h a n c o n v e n t i o n a l c o m m e r c i a l Cottage cheeses• To i m p r o v e these characteristics, in a

. . . . . . .

. . . . . . .



.

.. •

.

• .

.. •. ..

19.2

20.2 19.8 19.8 22.0 22.7 22.2

s e p a r a t e e x p e r i m e n t , t h e c u r d s were m a d e i n t o w h i p p e d c r e a m C o t t a g e cheese (Figure 4). C o l o r a n d a p p e a r a n c e scores i m p r o v e d . Cottage Cheese Curd Yields

O n e h u n d r e d k i l o g r a m s of skim milk concentrated by diafiltration with simultaneous f e r m e n t a t i o n p r o d u c e d 16.2 kg o f r e t e n t a t e (20% t o t a l solids). T h e r e f o r e , a c c o r d i n g to r e c o v e r y f a c t o r s (Table 1) t h e C o t t a g e cheese curd yield was 16.2 kg p e r 1 0 0 kg s k i m milk w i t h 100% r e c o v e r y a n d 15.4 kg with 95% recovery. DISCUSSION

Thurston and Gould (12)showed that heating of c o n v e n t i o n a l C o t t a g e cheese curds s h o u l d

TABLE 3. Composition of solids-non-fat in Cottage cheese made conventionally a and by ultrafiltration, b Sample

Protein

Lactose

Ash

Conventional Cottage cheese Ultrafiltered pre-cheese mix of Experiment 4

75.0

80.0

21.9 12.5

3.1 7.5

Ultrafiltered cheese Treatment 10 (Table 1) Treatment 11 (Table 1)

77.5 80.0

11.2 10.0

11.3 10.0

(%)

acontrol and experimental cheeses were adjusted 16% SNF. Mix was adjusted to 20% SNF. bFrom cheese made from retentates obtained by diafiltration with simultaneous fermentation (Experiment 4, Table 1). Journal of Dairy Science Vol. 61, No. 5, 1978

534

COVACEVICH AND KOSIKOWSKI

TABLE 4. Calcium, phosphorus, sodium, and potassium in Cottage cheese made conventionally and by using ultrafiltrationa (dry matter basis).

Sample

Calcium

Phosphorus

Sodium

Potasium

(%) Ultrafiltered pre-cheese mix of Experiment 4

1.9

.6 1.2

1.2 .1

.9 .8

Ultrafiltered cheeses Treatment 10 (Table 1) Treatment 11 (Table 1)

1.2 1.2

.8 .8

.7 .8

.7 .8

Conventional

.3

aFrom cheeses made by diafiltration with simultaneous fermentation (Experiment 4, Table 1).

be uniform until the proper degree of firmness was achieved. The final heating temperature was more important than the holding time, and t h e i r cheeses gained 2% moisture during w a s h i n g and cooling. Present experiments indicated that direct steam heating was effective for Cottage cheese curds made either by culturing or direct acidification from ultrafiltered milk and that any moisture loss could be partially recovered during cooling in chilled water. Cheeses made from retentates obtained by diafiltration with simultaneous fermentation (Experiment 4, Table 1) were selected for

FIG. 4. Whipped creamed Cottage cheese made by the ultrafiltration method. Journal of Dairy Science Vol. 61, No. 5, 1978

composition analysis, because, visually, they most closely resembled commercial Cottage cheese. These cheeses had lower lactose but higher protein and minerals than commercial Cottage cheese. This is attributable to the protein fractionation occurring during diafiltration. The higher calcium and lower sodium levels for the ultrafiltrated cheese have a ratio similar to that of milk. This gives Cottage cheese made by ultrafiltration a potential nutritional advantage over the standard product. Maubois (9) concluded that a high mineral concentration was undesirable in fresh, soft, unripened cheeses produced by ultrafiltration because of adverse flavor. In the present studies, retentates obtained by diafiltration with simultaneous fermentation, rather than by d i r e c t ultrafiltration, gave better flavored cheeses with a more uniform meaty body. This is attributable to a lower ash/protein ratio. Proper cream absorption was not attainable in Cottage cheese made by ultrafiltration. The curd was gelatinqike, and the cream was free. Better cream absorption and curd color was obtained when more viscous dressing mixtures were used or when curds were made into whipped cream Cottage cheese (Figure 4). Mattews et al. (11) reported that to avoid problems during traditional curd cooking when ultrafiltering skim milk for Cottage cheese, a concentration ratio for skim milk of 1:2 with a protein increase from about 3.2 to 6.2% apparently was the limit. It was possible to concentrate skim milk to 15% protein in the present study and cook curds uniformly and extremely rapidly using a single-layer cooking

COTTAGE CHEESE BY ULTRAFILTRATION principle. In p r a c t i c e , this m i g h t be d o n e b y first c u l t u r i n g r e t e n t a t e s in a vat a n d t h e n transf e t i n g t h e acid m i x t u r e i n t o a t r o u g h of u n i f o r m d e p t h . This w o u l d b e f o l l o w e d b y q u i c k c o o k i n g a n d single s t r o k e c u t t i n g . Proper texture and cream absorption by the c u r d s are i m p o r t a n t p r o b l e m s t h a t still m u s t be solved b e f o r e t h e m a k i n g of h i g h - p r o t e i n ret e n t a t e s ( 1 : 5 ) i n t o C o t t a g e cheese can be considered feasible. REFERENCES

1 Collins, E. B. 1958. Manufacturing Cottage cheese with pairs of single strain cultures of lactic streptococci. J. Dairy Sci. 41:492. 2 Covacevich, H. R., and F. V. Koskowski. I977. Skim milk concentration for cheese making by alternative ultrafiltration procedures. J. Food Sci. 42:1359. 3 Covacevich, H. R., and F. V. Kosikowsld. 1977. Cream cheese by ultrafiltration. J. Food Sci. 42:1362. 4 Emmons, D. B.,and W. V. Price. 1960. Observations on creaming of Cottage cheese. J. Dairy Sci. 43:931.

535

5 Emmons, D. B. 1963. Recent research in the manufacture of Cottage cheese. Parts I and II. Dairy Sci. Abstr. 25:129 and 25:175. 6 Kosikowski, F. V. 1970. Cheese and fermented milk foods. Edwards Brothers, Inc. Ann Arbor, MI 48104. 7 Marius, L. J. 1957. High viscosity Cottage cheese dressing. Milk Prod. J. 48(10): 56. 8 Maubois, J. L., and G. Mocquot. 1971. Preparation of cheese from a concentrate obtained by ultrafiltration of milk. Le Lait 51(508):495. 9 Maubois, J. L. 1973. Use of ultrafiltradon in the m a n u f a c t u r e of v a r i o u s c h e e s e varieties. Nordeuropaeisk Mejeri-Tiddskrift 39(3): 57. 10 Maubois, J. L., and G. Mocquot. 1975. Applications of membrane ultrafiltration to preparation of various types of cheese. J. Dairy Sci. 58:1001. 11 Mattews, S. E., C. H. Amundson, and C. G. Hill, Jr. 1976. Cottage cheese from ultrafiltrated skim milk. J. Food Sci. 41:619. 12 Searle, S. R. 1971. Linear models. John Wiley and Sons, Inc. New York, NY. 13 Thurston, L. M., and I. Gould, Jr. 1933. Factors governing the manufacture of sweet curd Cottage cheese. J. Dairy Sci. 16:467. 14 Van Slyke, L. L., and W. V. Price. 1952. Cheese. 2nd ed. Orange Judd Publishing Company, New York, NY.

Journal of Dairy Science Vol. 61, No. 5, 1978