Skim milk microfiltration: Impact on cheese composition, yield, and aging

1
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

2
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.

3
Introduction

• 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.

4
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.

5
Hypothesis

• 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.

6
Objectives

• 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.

7
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)

8
Materials and Methods

• 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).

9
Make Time (min)

• Trial 1
• control 1.3 X 1.6 X
  2.0X
• set-draw 110 97 88
  84
• draw-mill 154 156 158
  164
• Total 264 253
  245 248

10
Make Conditions

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

11
Materials and Methods

• Milk and Whey Analyses
• Solids - forced air, 4 h at 100oC
• Fat - Mojonnier
• Protein - macro-Kjeldahl (TN/NCN/NPN)
• Calcium - atomic absorption

12
Milk Composition, ()

• Trial 1 control 1.3 X 1.6 X
  2.0X
• TS 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

13
Whey Composition, ()

• Trial 1 control 1.3 X 1.6 X
  2.0X
• TS 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

14
Materials and Methods

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

15
Cheese Composition, ()

• Trial 1 control 1.3 X 1.6 X
  2.0X
• Moisture 35.25 34.56 34.42
  33.80
• Fat 34.47 34.75 34.80
  34.81
• Protein 24.95 25.11 25.25
  25.65
• Salt 1.47 1.46
  1.49 1.51
• pH 5.10 5.12 5.13 5.16
  

16
pH 4.6 Soluble Nitrogen
17
12 TCA Soluble Nitrogen
18
Results - Fat Recovery, ()

• 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 7.94
• salt whey 1.12 0.86 0.93
  0.67
• Total 100.44 99.88 100.00 99.67

19
Protein 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

20
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.

21
Cheese Yield Evaluation

• Actual Yield
• Moisture Salt Adjusted Yield (37 1.7)
• Modified VanSlyke Formula 1
• (0.93 fat) ( casein - 0.1) 1.09
• Yield -----------------------------------------
  ----------
• 1 - ( cheese moisture/100)

22

• Barbano Yield Formula
• A B C
• Yield ----------------------------------------
• 1- ((moisture salt)/100)
• A (0.93) x ( fat in milk)
• B ( casein in milk - 0.1) x 1.092
• C other milk solids retained in water phase of
  the cheese

23
Cheese Yield Evaluation

• Cheese Yield Efficiency
• Moisture Salt Adjusted Cheese Yield
• ---------------------------------------------
  -----
• Theoretical Yield
• CYE VS - VanSlyke
• CYE DMB- Barbano

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Cheese Yield, ()

• Trial 1 Control 1.3 X 1.6 X 2.0X
• Actual 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
  99.14
• Y eff.DMB 98.47 99.13 98.99 98.45

25
Acknowledgments

• Maureen Chapman
• Laura Landolf
• Joanna Lynch
• Pat Wood