I do not know a lot of Biol Mol, however I can tell you that a seed does not have a chloroplast. Chloroplast have a complex biogenesis where light is required to transform the amiloplasts and etioplasts into chloroplasts.

Before an etioplast exist there are amiloplasts as well. I would presumed that in a seed the amiloplast is where the genetic information to form a chloroplast would be stored. Check this paper, in particular Fig 1 for more info and Plastid Genome section for more info.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243408/

The DNA coding for a chloroplast is in the seed.  Otherwise the plant would not germinate with their chloroplasts.  The Chloroplast genome exists as it's own set of genes. It can be inherited from the maternal side, or, apparently from the pollen as well according to the paper listed below.

Paper about transmission

doi: 10.3732/ajb.94.8.1333

Am. J. Bot. August 2007 vol. 94 no. 8 1333-1337

Inheritance of chloroplast DNA is not strictly maternal in Silene vulgaris(Caryophyllaceae): evidence from experimental crosses and natural populations1

David E. McCauley2,

Allyson K. Sundby,

Maia F. Bailey3 and

Mark E. Welch

+Author Affiliations

Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235 USA

Received for publication 11 January 2007.

Accepted for publication 20 June 2007.

I think what your friends are trying to do is very unique idea and easily doable. 

The DNA of the chloroplast is the seed but in small quantities. It would be a lot easier just to germinate the seed and use young leaf of cotyledon tissue to make sure you have enough DNA for all the tests you need to do.

Sir

Each and every cell of a plant has structure known as Proplastids and Plastids which have DNA. Depending on their location and developmental stage the proplastids differentiate into plastids and subsequently into chloroplasts, 

The info listed below is from the attached paper (p. 60 yellow highlights):

1.  The establishment of a mature dry seed needs to go through three well-defined developmental stages---embryogenesis, maturation and desiccation 

2.  As in many oilseed crops, plastids undergo two differentiation processes during seed formation, i.e. chloroplast formation and chloroplast de-differentiation. Seeds become green at the beginning of 'maturation' (see attached picture for 'greening of the early stage of seed formation', picture was taken from the paper), and it has been proposed that photoheterotrophic plastids contribute to seed filling and seed quality by providing oxygen and ATP that are used for respiration and biosynthesis. 

3. Evidence also showed that at the end of seed maturation phase chloroplasts degenerate into reduced non-photosynthetic plastids, called eoplasts.

4. From (2. and 3.), the chloroplast genes should present in seed.

Yes very correct Plastids to chloroplasts and chloroplasts to eoplasts and again chloroplasts can be commonly observed by putting plants in dark and turning in to pale and again in light turning green. Chloroplasts can neither be created nor destroyed. They are inherited maternally and thus each seed will have de differentiated plastids and also proplastids which will have DNA to enable them to differentiate into fully developed plastids. Over 80 proteins of plastids are synthesized under dual control of nuclear genome and plastome 

This was more of a practical question rather than a question asking about the developmental processes of plastids en general. You will certainly detect plastid DNA in any oil if you use the correct protocol. Look for the protocols to determine transgenes in soybean and maize oil; it will be easier to amplify plastid DNA than nuclear genes.

@ Luis,

Of course, it is a practical question when it comes down to how to amplify a chloroplast gene with PCR in seed. However, only if we know the basic knowledge of chloroplast development, such as its differentiation and de-differentiation, in the seed, we can then obtain the best experiment (PCR in this case) results.

In the paper attached in my earlier post, it mentions that during seed maturation phase chloroplasts degenerate into reduced non-photosynthetic plastids, called eoplasts. What does 'degenerate' mean in that sense? Does the genome of the  eoplasts maintain the same as that of the chloroplasts which degenerate into them? Is mini-parts of the genome lost? Or some of the genes lost? Have any reports showing the comparisons the genome sequences between chloroplasts and eoplasts? If the genes which you intent to PCR lost, you would never get a PCR product even you have a perfect protocol.

I want to add that in some species of trees embryo stay green not only during developmental stage but also during maturation and dessication phase.

I work with carabids that have consumed seeds - identifying their seed choice via diagnostic PCR using general plant primers targeting the trnL exon - whicht is part of the cp genome. So in short: your friend ist right - I'm confiden this can be done.

Interesting discussion, I wonder which protocol is well optimized for DNA extraction from edible oil?