how I can minimize time of running of a code

I use a code to categorize data (by searching in text for words) this is the data(it consists of 40000 row):

i use this code:

 tic
 j=1;
k=1;
D=alldata(:,54);
 E=class(D{5});
for H = 1:R                       % for loop to remove NaN
  if isnan(D{H})
    D{H} = '';
  end
end
% 
for E=1:2            % from 1 : length of columns
   B=~cellfun('isempty',regexp(D,'deliver')) ;   %  search for battrey and return 1 or 0
if (B(E) == 1)               % if value of array greater than or equal 1
    Defs(j)=E;              % save its postion (E,1)
        j=j+1;
 else                     % save all arrays didn't have 'check' separately
        not(k)=E;
         k=k+1;
end
end
data=alldata(Defs,:);              % show data contains 'battery'
 notdata=alldata(not,:);             % show data didn't contain 
toc
xlswrite('result2000.xlsx',data,10);        % save result in sheet 4
xlswrite('result2000.xlsx',notdata,11);   

 but it takes very big time
2911 sec about 48 minute

and I need to run the code many times (searching for several words in 5 different columns)

how i could modify the code to run in less time ?

[Adam]

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...your code...

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is the best way to find the slow parts of your code to focus on for speeding up. tic toc is only really useful for getting an overview of a given section of code.