Skim milk microfiltration: Impact on cheese composition,

yield, and aging

M. Neocleous, D. M. Barbano, and M. A. Rudan. Northeast Dairy Foods Research Center, 1Cornell University, Ithaca, NY

Introduction

Skim milk microfiltration can be used to remove milk serum proteins from milk prior to cheese making.

The milk serum protein products will be superior to whey protein products and may have higher value.

This approach gives the same increase in concentration of milk casein and fat prior to cheese making as earlier approaches with UF. However, unlike UF, there is no attempt to retain whey proteins in the cheese to increase cheese yield.

Introduction

While retention of whey proteins in cheese using UF increased cheese yield, it had negative impacts on cheese functionality (e.g., Mozzarella) and cheese flavor development during aging (e.g., Cheddar). Thus, UF has not been very successful for these two varieties of cheese.

Introduction

Concentrating milk prior to cheese making with microfiltration (MF) should produce a cheese that has the same composition as cheese made without MF. Therefore, the cheese should have similar functionality and flavor development to control cheese.

Hypothesis

To determine the influence of skim milk microfiltration on the composition and make procedure at 1.3, 1.6, and 2X concentration factors for aged Cheddar cheese.

To determine if fat and protein recovery in the cheese and cheese yield efficiency are influence by microfiltration.

To determine if proteolysis and cheese aging are influenced by microfiltration.

Objectives

Experimental Design

• Trial 1: 4 x 4 Randomized Block (n = 16)–1.0, 1.3, 1.6 and 2X concentration factor–complete except for final aging data

• Trial 2: Paired comparison of 1.0 and 2X to try to adjust make procedure of 2X to achieve similar aging to the control. (planned for winter 1999/2000)

• Full-fat, milled-curd Cheddar cheese was made. Approximately, 220 kg of milk were used per vat of cheese.

• Mass/balance accounting was done for fat (Mojonnier) and protein (Kjeldahl).

Materials and Methods

Make Time (min)

Trial 1: control 1.3 X 1.6 X

2.0Xset-draw 110 97 88 84draw-mill 154 156 158 164Total 264 253 245 248

Make Conditions

Trial 1: control 1.3 X 1.6 X 2.0Xdraw pH 6.40 6.40 6.40 6.40mill pH 5.30 5.30 5.30 5.30rennet (%) 100 80 60 33cook (oC) 38 38 38 38Starter 911 911 911 911starter added based on cheese weight

• Milk and Whey Analyses–Solids - forced air, 4 h at 100oC–Fat - Mojonnier–Protein - macro-Kjeldahl

(TN/NCN/NPN) –Calcium - atomic absorption

Materials and Methods

Milk Composition, (%)Trial 1: control 1.3 X 1.6 X 2.0XTS 11.86d 13.34c 14.77b 16.48a

Fat 3.33d 4.21c 5.05b 6.11a

Protein(TN) 3.02d 3.65c 4.23b 4.95a

Casein 2.27d 2.88c 3.45b 4.15a

CN/TP 81.38d 83.90c 86.06b 87.52a

C/F 0.68 0.68 0.68 0.68

Whey Composition, (%)Trial 1: control 1.3 X 1.6 X 2.0XTS 6.84d 6.94c 7.09b 7.35a

Fat 0.28d 0.32c 0.40b 0.59a

Protein(TN) 0.93d 0.99c 1.04b 1.10a

NPN 0.27d 0.29c 0.31b 0.33a

• Cheese Analyses–Moisture - forced air, 24 h at 100 C–Fat - Babcock–Protein - macro-Kjeldahl–Salt - Volhard titration –Calcium - atomic absorption

Materials and Methods

Cheese Composition, (%)Trial 1: control 1.3 X 1.6 X 2.0XMoisture 35.25 34.56 34.42 33.80Fat 34.47 34.75 34.80 34.81Protein 24.95 25.11 25.25 25.65Salt 1.47 1.46 1.49 1.51pH 5.10 5.12 5.13 5.16

pH 4.6 Soluble Nitrogen

0

2

4

6

8

10

12

14

Control 1.3 X 1.6 X 2.0 X

Treatment

pH 4

.6 S

olub

le N

as

% T

N

day 41 month3 months6 months

12% TCA Soluble Nitrogen

0

1

2

3

4

5

6

7

8

Control 1.3 X 1.6 X 2.0 X

Treatment

12%

TC

A so

lubl

e N

as %

to T

N

day 41 month3 months6 months

Trial 1: control 1.3X 1.6X 2.0X cheese 91.74 92.46 92.43 91.06

whey 7.59 6.57 6.64 7.94salt whey 1.12 0.86 0.93 0.67Total 100.44 99.88 100.00 99.67

Results - Fat Recovery, (%)

Trial 1:control 1.3X 1.6X 2.0X

cheese 72.36 75.84 79.00 82.03

whey 27.27 23.39 20.50 17.95

salt whey 0.54 0.55 0.56 0.43

Total 100.17 99.86 100.07 99.90

Protein Recovery, (%)

Protein & Fat Recovery• Trial 1:

– fat recovery in cheese was lower than 93% due to cream separation and recombination

– no consistent trend in fat recovery– protein recovery in the cheese increased and

recovery in the whey decreased with increasing concentration factor as expected.

Cheese Yield EvaluationActual YieldMoisture & Salt Adjusted Yield (37 &

1.7%)Modified VanSlyke Formula 1

[(0.93 * % fat) + (% casein - 0.1)] *1.09Yield = ---------------------------------------------------

1 - (% cheese moisture/100)

Barbano Yield Formula A + B + CYield = ----------------------------------------

1- ((moisture + salt)/100)

A = (0.93) x (% fat in milk)B = (% casein in milk - 0.1) x 1.092C = other milk solids retained in water

phase of the cheese

Cheese Yield Efficiency = Moisture & Salt Adjusted Cheese Yield -------------------------------------------------- Theoretical Yield

CYE VS - VanSlykeCYE DMB- Barbano

Cheese Yield Evaluation

Cheese Yield, (%)Trial 1 Control 1.3 X 1.6 X 2.0XActual 8.81d 11.12c 13.33b 15.87a

Adjusted 9.06d 11.57c 13.89b 16.68a

TY VS 9.13d 11.58c 13.92b 16.82a

TY DMB 9.20d 11.67c 14.03b 16.94a

Y eff. VS 99.24 99.91 99.76 99.14Y eff.DMB 98.47 99.13 98.99 98.45

Acknowledgments

Maureen ChapmanLaura LandolfJoanna LynchPat Wood