The effect of processing temperatures on the quality of labneh made by ultrafiltration

Abstract

Twelve batches of labneh were manufactured by using the traditional method and also by ultrafiltration (UF) of yogurt at temperatures ranging from 35°‐55° C. The labneh samples contained 21.3–26.4% total solids (including minerals and unmetabolized lactose), 6.6–9.3% protein and 9.8–12.6% fat. The highest flux rate during UF was observed at temperatures 50° C, but the total viable counts of the starter organisms were lower when compared with labneh concentrated at 45° C. Portions of each of the labneh samples were smoothed using a lactic curd homogenizer fitted with different homogenizer heads (D‐170 and D‐280). Homogenization markedly affected the firmness of labneh and is therefore recommended to smooth the product using homogenizer head D‐280 because it causes less turbulence.

The pre-concentration of milk by nanofiltration in the production of Quarg-type fresh cheeses

“…These figures were lower than those found in traditional Italian fresh cheese [13] and higher than those found in UF Quarg [2]. In the latter case the difference may be due to a combined acidity -high UF temperature effect on the viability of starter bacteria during UF Quarg production [18], as evidenced also by Tamine [16] during Labneh production by UF.…”

Manufacturing, properties and shelf life of labneh: a review

“…The degree of concentration using a four‐stage UF plant could be adjusted to give 14, 16, 19 and 22 g 100 g −1 TS, respectively. However, the highest flux rate during UF was observed at a temperature ≥ 50°C, but the total viable counts of the yogurt starter organisms were lower than with labneh ultrafiltered at ≤ 45°C (Tamime et al . 1991).…”

“…1991). It is possible to recommend that UF of yogurt should be operated at 45–50°C, since at this high temperature, labneh can be produced within the shortest time, and the firmness of the product is similar to the traditional labneh (Tamime et al . 1991).…”

Preconcentration of yoghurt base by ultrafiltration for reduction in acid whey generation during Greek yoghurt manufacturing

“…Most of the work to date on Greek yoghurt has been conducted by following the traditional processing method, which involved draining whey after fermentation (Tamime et al . ; Ozer et al . ; Ozer and Robinson ) with the use of UF.…”

“…Among them, UF is widely used in the industry as it leads to a high protein concentration and enhanced yoghurt gel strength compared to the other filtration methods (Tamime and Robinson 1999). Most of the work to date on Greek yoghurt has been conducted by following the traditional processing method, which involved draining whey after fermentation (Tamime et al 1991;Ozer et al 1997; with the use of UF. Only a small proportion of the studies have investigated the application of UF prior to fermentation, by studying its effect on starter culture activity, rheological properties and microstructure of Greek yoghurt ).…”