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FSB1 – 2004
Food Science and Biotechnology in Developing Countries
EVALUATION OF SOME CHEMICAL AGENTS TO INHIBIT THE ENZYMATIC BROWNING IN
HAWTHORN (Crataegus mexicana)
Abstract.
Pluma-Alvarado V. (1) , López-Valdez F. (2) and Luna-Suárez S. (3)
(1) CICATA-IPN PUEBLA, Acatlán 63 La Paz, Puebla, Pue. México 72160.
vianp_a@yahoo.com.mx
(2) CICATA-IPN PUEBLA, Acatlán 63 La Paz, Puebla, Pue. México 72160.
flopezva@ipn.mx, flopez2072@yahoo.com
(3) CICATA-IPN PUEBLA, Acatlán 63 La Paz, Puebla, Pue. México 72160.
sluna@ipn.mx, silvials2004@yahoo.com.mx
Tel.: 52 (222) 230 - 4459, Tel/Fax: 249 - 8540.
We evaluated the effect of some chemical agents to inhibit the enzymatic browning in hawthorn, as
inhibitors were used solutions: salt, sugar, citric acid, ascorbic acid and its combinations. The
peroxidase and catalase activities were evaluated, in addition to color change in the exposition to air
for 24h. The peroxidase´s best treatments were salt-sugar-citric and salt-sugar-ascorbic-citric; to
inhibit catalase, salt-sugar-ascorbic acid. The worst treatment for enzymes was salt but not for
exposition to air.
Key words: Enzymatic browning, hawthorn, peroxidase and catalase.
Introducción.
Appearance, flavor, texture and nutritional value are attributes considered by consumers when making
food choices. Appearance which is significantly impacted by color is one of the first attributes used by
consumers in evaluating food quality. Color may be influenced by naturally occurring pigments such
as chlorophylls, carotenoids and anthocyanins in food, or by pigments resulting from both enzymatic
and non-enzymatic reactions. Enzymatic browning is one of the most important color reactions that
affect fruits and vegetables. It is catalysed by enzymes like polyphenol oxidase (1,2 benzenediol;
oxygen oxidoreductase, EC1.10.3.1) catalase and peroxidase.
Enzymatic browning does not occur in intact plant cells since phenolic compounds in cell vacuoles are
separated from the enzymes which are present in the cytoplasm. Once tissue is damaged by slicing,
cutting or pulping, the formation of brown pigments occurs. Both the organoleptic and biochemical
characteristics of fruits and vegetables are altered by pigment formation. The rate of enzymatic
browning in fruit and vegetables is governed by the active enzymes content of the tissues, the
phenolic content of the tissue, pH, temperature and oxygen availability within the tissue (1).
Enzymatic browning is one of the most studied reactions in fruits and vegetables. Many researches
have been done this field, and many agents have been tested to prevent this reaction. The more used
are the antioxidants. Although, in hawthorn (Crataegus mexicana) there are low studies. Hawthorn is
an autochthon fruit from Mexico, this fruit is susceptible to enzymatic browning in oxygen contact or
mechanical damage as many fruits.
The objective of this work was to evaluate some chemical agents to inhibit the enzymatic browning in
hawthorn (Crataegus mexicana).
Material and methods
Fresh hawthorn was supplied by a Puebla producer. The fruit was cleaned by water and submerged in
0.02% sodium hypochlorite solution to disinfection.