The Study of Labneh Processing by Adding Different rates of Milk Solids and the identification of the Optimal Conditions for Processing

Mohamad Ibrahem Al-Shehabi
General Commission for Scientific Agricultural Research- Department of Food Technology,
Faculty of Agriculture,Damascus University,
2008

 Abstract

     18 mixtures of labneh which are different from the percentage and kind of added solids were produced to identify the optimal percentage of solids and fat in the labneh made in the direct way(direct control of structure).

It seems that mixture 3, which contains 26% of total solids and 6% fat, is the best mixture in terms of sensory properties , so that mixture 3 has been chosen to apply the rest of deals ( starter type, starter rate ,incubation time, the rate of added salt before incubation).

To choose the best starter,8 mixtures similar in the percentage of their total solids 26% were produced and inoculated by 8  different types of starters (CH1, YC180,LB12, YC-X11,YF-L811,YC350,TH4,R704) in rate of 4% and incubated for 6 hours  at 44 c , the result of evaluation assured that the best starter is CH1. After that 8 mixtures similar in ( total solids 26%) were manufactured and inoculated by different proportions of starter CH1(1%,2%,3%4%,5%,6%,7%,8%), and were incubated for 6 hours at 44 c. It has been discovered that the best starter rate is 4%.Then,

5 mixtures similar in ( the rate of total solids 26% , the rate of starter CH1 4%)were manufactured and incubated  for different times (4,5,6,7,8 hours) at 44c. It was apparently noticed that the best incubation time is 6 hours.

Finally 6 mixtures similar in (the rate of solids 26% , the rate of starter

CH1 4%)were manufactured and different rate of salt was added to these mixtures (0.0%,0.2%,0.4%,0.6%,0.8%,1.0%) and incubated for 6 hours at 44c . It was found that the mixture which is free of salt was the favorite ,therefore the best mixture was the mixture which contains 26% of  total solids, free of salt, inoculated with starter CH1 in the rate of 4%,and incubated for 6 hours at 44c).

By comparing labneh made in the direct way ( direct control of structure ) to labneh made in the traditional way (cloth bags) and labneh taken from market ,it has been found the following :

Chemically speaking,  it was no morale differences in the percentage  of  acidity and fat between labneh made in  the  direct way, and both of labneh made in the traditional way and  labneh taken from market .

Microbiologically speaking, labneh which made in the direct way comes  first then labneh made in the traditional way comes second (number of molds and yeast was   5.125 × 10² cfu/g ) . Finally, Labneh taken from market  comes third  (number of molds and yeasts 6.6 × 10² cfu/g ,and number of coliform was 9.75 × 10 cfu/g , and the  number of E.coli was 1.0 × 10 cfu/g) .

Sensorily speaking, it has been found that there were no morale differences  between labneh made in the direct way, and both of labneh made in the traditional way and  labneh taken from market .

As for the costs of production, the cost of labneh made in the direct way was lesser  than that of labneh made in the traditional way (manual filling or auto filling) .

Key words: labneh,direct way, mixture , starter, total solids, rate of starter, time of incubation.