EFFECT OF PARTIAL SUBSTITUTION OF SUPPLEMENTARY SKIM MILK POWDER WITH DEFATTED APRICOT KERNEL POWDER ON THE QUALITY OF ICE CREAM AND YOGHURT

Defatted apricot kernel powder (DAKP) was added as a supplementary protein source while making ice cream and yoghurt in different ratios ranging from 10-50% for ice cream and 10-40% for yoghurt to replace a part of added skim mRk powder (SMP). Values of ice cream pH, specific gravity and weight per gallon increased by increasing amount of DAKP. Irrespective of the replacement level, higher protein stability was noticed. Supplementing with DAKP led to reduce the overrun of the resulting ice cream. However, the use of DAKP deteriorated the flavor more than body and texture and appearance of the resulting ice cream. Substitution of supplementary SMP by DAKP in ice cream could be recommended up to 30%. When supplementary SMP was replaced by DAKP in yoghurt manufacture, the average titratable acidity, total solids, total nitrogen, tyrosine, tryptophan and nonprotein nitrogen contents of yoghurt were increased by increasing DAKP. Conversely, pH and acetaldehyde values decreased with increasing of DAKP. Also, addition of DAKP led to a decrease in the counts of lactic acid bacteria and psychrotrophic bacteria in the resultant yoghurt when either fresh or after cold storage for 7 days. Substitution of supplementary SMP with DAKP in the manufacture of yoghurt could be recommended up to 20%.