Dairy Ingredients for Food Processing

Dairy Ingredients in Dairy Food Processing 445

Table 17.14. Some quality issues and their remedies in the manufacture of buttermilk and sour

cream.

Defect Possible cause Remedy

Not enough fl avor Low citrate level in mix.

Diacetyl destroyed

Incorporate 0.02% – 0.05% sodium citrate to the mix

before culturing. Cool rapidly after culturing.

Agitate gently to avoid incorporating oxygen.

Green/yogurt fl avor Acetaldehyde accumulation Avoid the use of Lactococcus lactis subsp.

diacetylactis

Cardboard fl avor Copper contamination and

exposure to sunlight/

fl uorescent light

Avoid exposure to copper utensils.

Protect packages from direct exposure to sunlight

and source of UV light.

Yeast/cheese - like

odor/fl avor

Contamination with yeast

and its growth

Check sanitation procedure. Avoid return milk in

formulation

Rancid fl avor Lipase activity Avoid mixing of raw milk and pasteurized product

streams

Weak body Insuffi cient heat treatment.

Too low MSNF. Too

severe agitation after

culturing.

Ensure correct heat treatment: 85 ° C/30 minutes for

buttermilk and 74 ° C/30 minutes for sour cream.

Fortify with 0.5% – 1% NFDM for buttermilk and

2% – 3% for sour cream. Check stabilizer use.

Use rennet in sour cream formulation.

Grainy texture Acidity too high.

NFDM is not dispersed

properly.

Check processing procedure for acidity control.

Ensure full dispersion of NFDM. Use in - line

screen to remove large particles.

Chalky/powdery

texture/mouth feel

Too much NFDM in

formulation

Check the quality and quantity of NFDM

Adapted from Chandan and Shahani (1995)

Table 17.15. Annual total and per capita sales of refrigerated yogurt in the United States.

Year Yogurt Sour cream and dips Buttermilk

Sales

(million pounds)

Per capita sales

(pounds)

Sales

(million pounds)

Per capita sales

(pounds)

Sales

(million pounds)

Per capita sales

(pounds)

2005 3,058 10.3 1,309 4.4 512 1.7

2006 3,301 11.0 1,256 4.2 504 1.7

2007 3,476 11.4 1,313 4.32 508 1.7

2008 3,599 11.8 1,274 4.19 547 1.8

Adapted from International Dairy Foods Association, Dairy Facts (2009)

from a mix standardized from whole, par-

tially defatted milk, condensed skim milk,

cream, and nonfat dry milk. It is common to

supplement MSNF in the mix with NFDM.

The FDA specifi cation (CFR, 2009 ) calls for

a minimum of 8.25% nonfat milk solids

(SNF). However, the industry uses up to 12%

SNF in the yogurt mix to generate a thick,

custard - like consistency in the product. The

milk fat levels are standardized to 3.25% for

full - fat yogurt. Reduced fat yogurt is made

from mix containing 2.08% milk fat. Low - fat

yogurt is manufactured from mix containing

1.11% milk fat. Nonfat yogurt mix has milk

fat level not exceeding 0.5%. These fat levels

correspond to the FDA requirement for nutri-

tional labeling of nonfat, reduced - fat and

low - fat yogurt (Frye and Kilara, 2008 ). All

raw dairy materials should be selected for

high bacteriological quality.

Yogurt starters. A starter consists of

food - grade microorganism(s) which, on cul-

turing in milk, produce predictable attributes

characterizing yogurt. The composition of