Background: Thylakoids and chloroplasts harbor several vital metabolic processes, but are
most importantly associated with photosynthesis. The undisturbed functioning of this process necessitates
the ceaseless synthesis of photosynthetic pigments, including closed tetrapyrroles such as chlorophylls
(Chls). Chls probably represent the most abundant natural pigment molecules which are via
photosynthesis not only crucial for the autotrophic production of food sources for heterotrophic organisms
but have also contributed to oxygen production essential for aerobic metabolism.
Objectives: This review first briefly discusses the physico-chemical properties, biosynthesis, occurrence,
in vivo localization and roles of the different Chl pigments. Then we provide a detailed overview
of their potential applications in the food industry and medicine. These include the use of Chls and
their derivatives (different chlorophyllins) as food colorants (identified as E140 and E141 in the European
Union). Different sources used for industrial extraction as well as different factors influencing
pigment stability during processing are also critically reviewed. The problems surrounding the nomenclature,
the production and the composition of different chlorophyllin mixtures are also discussed. Finally,
a comprehensive overview of the health benefits and potential medicinal applications of these
pigments and the future directions of research in these fields are provided.