Food Biochemistry and Food Processing (2 edition)

BLBS102-c18 BLBS102-Simpson March 21, 2012 13:30 Trim: 276mm X 219mm Printer Name: Yet to Come

18

Biochemistry of Fermented Meat

Fidel Toldra ́

Background Information

Raw Material Preparation

Ingredients

Other Ingredients and Additives

Starters

Lactic Acid Bacteria

Micrococcaceae

Yeasts

Molds

Casings

Processing Stage 1: Comminution

Processing Stage 2: Stuffing

Processing Stage 3: Fermentation

Fermentation Technology

Microbial Metabolism of Carbohydrates

Processing Stage 4: Ripening and Drying

Physical Changes

Chemical Changes

Processing Stage 5: Smoking

Safety

Finished Product

Color

Texture

Flavor

Ta s t e

Aroma

References

Abstract:A wide variety of fermented sausages are produced, the

type and composition depending on the raw materials, microbial

population, and processing conditions. Undry and semidry sausages

are fermented to reach low pH values, and are usually smoked and

cooked before consumption. Dry-fermented sausages experience

a long drying after fermentation reaching low water activity val-

ues. This chapter describes the raw ingredients including microbial

starters used for the manufacture of fermented sausages as well as

its main processing stages. The physical and chemical changes that

take place during processing are also described.

BACKGROUND INFORMATION

The origin of fermented meats is quite far away in time. Ancient

Romans and Greeks already manufactured fermented sausages,

and, in fact, the origin of words like sausage and salami might

have come from the Latin expressionssalsicciaandsalumen,

respectively (Toldra 2002). The production and consumption ́

of fermented meats expanded throughout Europe in the Mid-

dle Ages, being adapted to climatic conditions (i.e., smoked in

Northern Europe and dried in Mediterranean countries). The ex-

perience in manufacturing these meats went to America with

settlers (e.g., states like Wisconsin still have a good number

of typical Northern European sausages like Norwegian and

German sausages).

Today, a wide variety of fermented sausages are produced,

depending on the raw materials, microbial population, and pro-

cessing conditions (Toldr ́a et al. 2007). For instance, Northern

European-type sausages contain beef and pork as raw meats,

are ripened for short periods (up to 3 weeks), and are usually

subjected to smoking. In these sausages, shelf-life is mainly due

to acid pH and smoking rather than drying. On the other hand,

Mediterranean sausages mostly use only pork and are ripened

for longer periods (several weeks or even months), and smoke

is not so typically applied (Flores and Toldra 1993). Examples ́

for different types of fermented sausages, according to the in-

tensity of drying, are shown in Table 18.1. Undry and semidry

sausages are fermented to reach low pH values, and are usually

smoked and cooked before consumption. Shelf-life and safety is

mostly determined by pH drop and reduced water activity (aw)

as a consequence of fermentation and drying, respectively. The

product may be considered stable at room temperature when pH

<5.0 and the moisture:protein ratio is below 3.1:1 (Sebranek

2004). Moisture:protein ratios are defined for the different dry

and semidry fermented sausages in the Unites States, whileaw

values are preferred in Europe.

Food Biochemistry and Food Processing, Second Edition. Edited by Benjamin K. Simpson, Leo M.L. Nollet, Fidel Toldr ́a, Soottawat Benjakul, Gopinadhan Paliyath and Y.H. Hui.

©C2012 John Wiley & Sons, Inc. Published 2012 by John Wiley & Sons, Inc.

331