BLBS102-c17 BLBS102-Simpson March 21, 2012 11:52 Trim: 276mm X 219mm Printer Name: Yet to Come
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Chemical and Biochemical Aspects of Color
in Muscle-Based Foods
Jose Angel P ́ erez-Alvarez and Juana Fern ́ andez-L ́ opez ́
General Aspects of Muscle-Based Food Color
Chemical and Biochemical Aspects of Color
in Muscle-Based Foods
Cytochromes
Carotenes
Hemoproteins
Structure of Myoglobin
Chemical Properties of Myoglobin
Color Characteristics of Blood Pigments
Fat Color
Reduced Nitrite Meat Products
Alterations in Muscle-Based Food Color
Pink Color of Uncured Meat Products
Melanosis
Premature Browning
Color and Shelf Life of Muscle-Based Foods
Microorganisms and Color
ReferencesAbstract:The term muscle-based foods encompass food products
derived from cattle, hogs, poultry, fish, and shellfish. Various factors
influence the quality of muscle food products during various han-
dling, processing, and storage. In this regard, color plays a crucial
role in consumers’ perception and acceptance of muscle-based food
products. The purplish-red to bright red color in muscle foods is due
to the myoglobin pigment, and the postmortem changes in its color
are useful indicators of the state of freshness of the source material.
This chapter discusses various postmortem biochemical and related
effects of the pigment in foods derived from these animals during
processing and storage.GENERAL ASPECTS OF MUSCLE-BASED
FOOD COLORThe first impression that a consumer receives concerning a food
product is established visually, and among the properties ob-
served are color, form, and surface characteristics.All meats and muscle-based foods have a number of visually
perceived attributes that contribute to their color and appear-
ance as well as to their overall quality. According to Lozano
(2006), the appearance can be divided in three different cate-
gories: color, cesia, and spatial properties or spatiality. Color
is related to optical power spectral properties of the stimulus
detected by observers (Hutchings 2002). Cesia include trans-
parency, translucence, gloss, luster, haze, lightness, opacity, and
matt, and is related to the properties of reflecting, transmitting,
or diffusing light by foods evaluated by human observation.
Spatial properties are divided in two main groups: (i) modes of
appearance in which color is modified depending on the angle of
observation related to the light incidence angle, such as metallic,
pearlescent, or iridescent materials, and (ii) modes of appearance
related to optical properties of surfaces or objects in which ef-
fects of ordered patterns (textures) or finishing characteristics of
food (as roughness, polish, etc.) (Lozano 2006).
Color is the main aspect that defines a food’s quality and
a product may be rejected simply because of its color, even
before other properties, such as aroma, texture, and taste, can
be evaluated. This is why the appearance (optical properties,
physical form, and presentation) of meat products at the sales
point is of such importance for the meat industry (Lanari et al.
2002). As regards the specific characteristics that contribute to
the physical appearance of meat and muscle-based foods, color
is the quality that most influences consumer choice (Krammer
1994).
The relation between meat color and quality has been the
subject of study since the 1950s since, indeed, Urbain (1952)
described how consumers had learnt through experience that the
color of fresh meat is bright red; and any deviation from this color
(nonuniform or anomalous coloring) is unacceptable (Diestre
1992). The color of fresh meat and associated adipose tissue
is, then, of great importance for its commercial acceptability,
especially in the case of beef and lamb (Cornforth 1994) and inFood 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.317