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

340 Part 3: Meat, Poultry and Seafoods

Figure 18.8.Picture of a typical small-diameter salchichon, ́

showing its cross section.

Color is also influenced by pH drop rate and the ultimate pH,

but it may be also affected by the presence of spices like red

pepper. An excess of acid generation by lactobacilli may also

affect color.

The characteristic color is due to the action of nitrite with myo-

globin. Nitrite is reduced to nitric oxide, favored by the presence

of ascorbate/erythorbate. Myoglobin and nitric oxide may then

interact to form nitric oxide myoglobin, which gives the charac-

teristics cured pinkish-red color (Pegg and Shahidi 1996). This

reaction is favored at low pH. Long-processing sausages using

nitrate need some time for the growth of Micrococcaceae before

pH drops. Nitrate reductase, which is present in Micrococcaceae,

reduces nitrate to nitrite, which is afterwards further reduced to

nitric oxide, which can react with myoglobin. Oxidative discol-

oration consists in the conversion of nitrosylmyoglobin to nitrate

and metmyoglobin, which affects the oxidative stability because

of the pro-oxidant effect of ferric heme.

Texture

The consistency of fermented meats is initiated with the salt ad-

dition and pH reduction. The water-binding capacity of myofib-

rillar proteins decreases as pH approaches its isoelectric point

and releases water. The solubility of myofibrillar proteins is also

reduced, with a trend toward aggregation and coagulation, form-

ing a gel. The consistency of this gel increases with water loss

during drying. So, there is a continuous development of textural

characteristics such as firmness, hardness, and cohesiveness of

meat particles during drying (Toldr ́a 2002). The meat:fat ratio

Table 18.5.Quality Aspects: Generation or Presence of Desirable Nonvolatile Compounds Contributing to Taste in

Fermented Meats

Group of

Compounds

Main Representative

Compounds

Routes of

Generation Presence in Final Product

Main

Contribution

Expected

Intensity

Peptides Tri and dipeptides Proteolysis Increases with length of process Taste High

Free amino acids Glutamic acid,

aspartic acid,

alanine, lysine,

threonine

Proteolysis Increases with length of process Taste High

Nucleotides and

nucleosides

Inosine

monophosphate,

guanosine

monophosphate,

inosine,

hypoxanthine

ATP degradation Around 100 mg/100 g Taste

enhancement

Low

Long chain free

fatty acids

Oleic acid, linoleic

acid, linolenic

acid, arachidonic

acid, palmitic acid

Lipolysis Increases with length of process Taste Low

Short chain fatty

acids

Acetic acid,

propionic acid

Microbial

metabolism

Depends on microflora Taste Medium

Acids Lactic acid Glycolysis Depends on initial amount of

sugar and fermentation

Sour taste High

Carbohydrates Glucose, lactose Remaining

(nonconsumed

through

glycolysis)

Depends on initial amount of

sugar and microflora

Sweet taste Low

Inorganic

compounds

Salt Addition Depends on initial amount Salty taste High