Dear all
I am associated with agriculture sector since 1993 first as an under graduate student and now as a scientist. Have closely observed the crop breeding programmes and variety release criteria. Till date only criteria is increase in yield over the best check crop variety. At present only change has happened is that protein content is needed for release of varieties in cereals and pulses. But protein content to be higher than check variety is not binding as still yield is the main criteria.
As we look for higher yields one of the important yield contributing trait is bold grains, if we do comparative analysis of bold grains vs small grains, it is very clear that bold grains have more of starch and less protein and minerals.
when we look towards soil health, than the answer is obviously lying in why are we looking for organic agriculture. As excessive use of chemical fertilizers viz. Urea, Muriate of Potash (MOP), Single super phosphate (SSP) has resulted in decline in soil organic carbon, soil cation exchange capacity as a result their capacity to store minerals has also reduced.
Off course their are many factors which may be responsible for an over all impact on nutrient density but there is no denying that the varieties developed with aim of improving productivity and excessive use of chemical fertilizers (again aimed for increasing production) has also contributed for low nutrient density in the food crops.
It would be good idea that for any crop variety to be released (may be still on yield basis) nutrient profile for proximates, minerals and vitamins be made mandatory. This will help us to track on nutrient composition of new varieties released for cultivation.
Rakesh
 Dr. Rakesh Bhardwaj Senior Scientist (Biochemistry) Germplasm Evaluation Division National Bureau of Plant Genetic Resources (NBPGR) PUSA Campus, New Delhi - 110 012 India Phone (+91)11-25848074(O),(+91)11-25842495(Fax) (+91)9560487889 (M), (+91) 9015405449

      From: Lidan Du <[log in to unmask]>
 To: [log in to unmask] 
 Sent: Monday, July 25, 2016 7:24 PM
 Subject: Fwd: Have nutrient contents in our foods been declining over time?
  


Hi, all, 
I have a question about nutrient contents of foods as shown in food composition tables. Do you think soil depletion and the single-focus on yield by the agriculture sector over the decades might have caused the foods we consume now be less nutritious by unit weight than before?  And if so, are the values in food composition tables in countries regularly updated? Are the current values reliable to support modeling exercises
A simple google search opened up a few discussions, and I would really appreciate your view on this.  
http://www.scientificamerican.com/article/soil-depletion-and-nutrition-loss/ "University of Texas (UT) at Austin’s Department of Chemistry and Biochemistry was published in December 2004 in theJournal of the American College of Nutrition. They studied U.S. Department of Agriculture nutritional data from both 1950 and 1999 for 43 different vegetables and fruits, finding “reliable declines” in the amount of protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and vitamin C over the past half century. "
https://www.theguardian.com/lifeandstyle/2005/may/15/foodanddrink.shopping3"David Thomas - a geologist turned chiropractor (who also happens to sell mineral supplements) - analysed data from McCance and Widdowson's epic work, The Composition of Foods (a reference manual republished and updated by Government biochemists every few years). During that 51-year period, potatoes appeared to have lost 47 per cent of their copper, 45 per cent of their iron and 35 per cent of their calcium while carrots showed even bigger declines. Broccoli - a 'superfood' rich in micronutrients and cancer-busting antioxidants - suffered an 80 per cent drop in copper while calcium content was a quarter of what it had been in 1940, a pattern repeated in tomatoes. As Thomas pointed out: 'You would need to have eaten 10 tomatoes in 1991 to have obtained the same copper intake as from one tomato in 1940."
Thank you very much. 

Best,-Lidan
Lidan Du, PhDResearch Advisor1616 N Ft Myer Drive, 16th Floor, Arlington, VA 22209Tel: 703-310-5047  |  Email: [log in to unmask]



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