Manufacture of Labneh from Cow's MilkUsing Ultrafiltration Retentate with or WithoutAddition of Permeate Concentrate

Abstract

Chemical composition, rheological properties and sensory evaluation of fresh labneh made from cow's milk, using ultrafiltration (UF) retentate and traditional process were investigated. Coagulation times showed a synergetic effect of addition of both GDL (1%) and permeate concentrate (1%) on coagulation time of labneh where the two components have been accelerated the acidity development. Consequently, the coagulation time becomes shorter. Addition of 1% permeate concentrate, 1% or 2% GDL already increased total solids significantly. Chemical composition of labneh showed that total solids, total protein, soluble protein, fat, ash, acidity and pH were increased in labneh made from UF retentate comparing with that traditionally prepared. pH was higher in UF labneh although acidity content was markedly higher than that of traditionally prepared one due to the buffering capacity of high content of protein in retentate. Soluble protein content was trebled in UF retentate labneh. Lactose content was lower in UF labneh than control except those treatments where permeate concentrate was added. Texture profile test showed that a correlation between acidity, coagulation time and hardness may be exist. Results also showed that there is no definite correlations between the additions of permeate concentrate or GDL and springiness or adhesiveness of labneh. Addition of 1% permeate concentrate has lowered the cohesiveness values, while addition of 1% GDL had no effect. Values of resilience are consistent with those of cohesiveness. Wide variations were observed among treatments. Addition of 1% permeate concentrate to the UF labneh improved the appearance, consistency and flavor of produced labneh.