Thursday, 24 May 2012

Making the Decaf Coffee Plants


  There are reasons why people want coffee without caffeine in it. Some, for medical reasons, cannot have caffeine in their diet, others just prefer coffee without the buzz.



  Process of extracting caffeine out of the coffee beans or decaffeination, using dichloromethane or ethyl acetate often destroyed the flavor and alter the taste of coffee. Some people argue that the chemical extraction might involved the use of potentially harmful substances. Thus, this process is clearly not a good one as it is expensive too.
  Well, for years scientists have been trying to produce coffee beans with strains that are free of caffeine. For example, through the process of hybridisation, the mating or crossing of two true-breeding varieties (Reece et al. 2012)[i]. In this case, scientists recognized the caffeine free species of coffee, and crossed it with better-tasting coffee. In fact, an experiment has been carried out to study a hybrid germplasm of Coffea racemosa and Coffea canephora var. robusta F1 for crop duration, caffeine content and some other important morphological characters. Coffea racemosa is a wild species with desirable characters such as low caffeine content. Coffea canephora var. robusta F1 are easier to grow (e.g., more “robust”) because they tolerate less favorable soil and climate conditions. They also have resistance to disease. The hybrid plants showed improvement over the mid parent values, and caffeine content were considerably low in the hybrid plants. This indicates the feasibility of racemosa x robusta protocol for the production of more desirable hybrids from robusta coffee plants. (V.B. Sureshkumar, N.S. Prakash, K.V. Mohanan, 2010)[ii]
  
   Scientists also carried out a genetic approach that is to genetically modify the genes of coffee. They inserted the desired genes into beans to make caffeine-free coffee. “Hiroshi Sano and colleagues at the Nara Institute of Science and Technology in Japan used a technique called RNA interference to silence a key gene for making caffeine in coffee plants. This technique cut caffeine in young coffee plants by up to 70 per cent.” (Shaoni Bhattacharya 2003)[iii]


(Brendan Borrell 2012)[iv]


  But challenges are there, cross breeding of coffee trees requires a lot of time because coffee trees take years to start producing beans while genetically modified coffee beans are difficult to produce, and transgenic plants are still not widely accepted by consumers.
  Scientists then seek for other ways to harvest caffeine-free coffee directly from the plant. In fact, they carried out a process called mutagenization, which hastens mutations of seedlings by using radiation or chemicals, thus creating variation in traits of coffee plants.


In 1983, Paulo Mazzafera joined Carvalho at the institute as a graduate student and began looking for ways to breed a caffeine-free strain. He prefers his coffee caffeinated. (Brendan Borrell 2012 p266)[v]


   In the year 2006, scientist Paulo Mazzaferra carried out mutagenization process. He took the seeds of a productive C. Arabica variety, soaked them in chemicals that cause mutations, and then screened the caffeine levels of 28,000 seedlings. He ended up with 7 plants that have only 2% of normal caffeine levels. Clearly, he had successfully created seedlings which are free of caffeine. But challenges remain, the strain is susceptible to cross pollination, which can reinstate caffeine production in the beans. (Brendan Borrell 2012 p266)[vi]
  In conclusion, scientists are still carrying out ways to produce caffeine-free coffee plants so that we can have a good cup of decaf coffee.
References

[i] Reece, Meyers, Urry, Cain, Wasserman, Minorsky, Jackson, Cooke, 2012, Campbell biology / Jane B Reece … [et al.], 9th ed. (Australian version), Pearson Australia Group Pty Ltd., Copyright @ 2012, Printed in China

[ii] V.B. Sureshkumar, N.S. Prakash, K.V. Mohanan (2010) A Study of Coffea racemosa x Coffea canephora var. robusta Hybrids in Relation to Certain Critically Important Characters. International Journal of Plant Breeding and Genetics, 4: 30-35. viewed 17 March 2012, http://scialert.net/fulltext/?doi=ijpbg.2010.30.35&org=10

[iii] Shaoni Bhattacharya (2003) Journal reference: Nature (vol 423, p 823) viewed 17 March 2012, http://www.newscientist.com/article/dn3851-genetic-engineers-decaffeinate-coffee.html

[iv] Brendan Borrell (2012). Plant Biotechnology: Make it a Decaf. Nature (vol.483, p.264-266).viewed 17 March 2012,

[v] Brendan Borrell (2012). Plant Biotechnology: Make it a Decaf. Nature (vol.483, p.264-266).viewed 17 March 2012,

[vi] Brendan Borrell (2012). Plant Biotechnology: Make it a Decaf. Nature (vol.483, p.264-266).viewed 17 March 2012,

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