The figure was presented before the NDMC House during a special meeting today.
Officials said the food was not found to be contaminated or adulterated but it lacked prescribed protein and calorie content.
Over four lakh students are being served the mid-day meal in around 775 schools under NDMC.
Presenting the official data, Leader of the House Mahendra Nagpal demanded to know how the NGOs supplying mid- day meal were being allowed to run despite this "high failure rate".
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According to the official reply furnished before the House, the samples were taken during the past year of food prepared by Maitri Research, Stri Shakti, Indcare Trust, M/S Surya Charitable and Welfare Society and ISCKON.
While in some cases, the samples passed either protein or calorie content standard, only in seven cases did they pass both the test.
All the samples, however, tested negative for E.Coli and Salmonella. In his reply, Commissioner P K Gupta contended that none of the samples were found to be adulterated.
"The E.Coli and Salmonella content has not been found even in a single sample. The only deficiency has been found in protein and calorific content, which is a nation-wide issue and not specific to NDMC. The government is working to improve the menu and as soon as we receive the guidelines in the case, we will implement them," he said.