Ultra filtration (UF) process development for the production of camembert cheese : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University, Albany, New Zealand.
The application of UF technology in cheese production has several potential
advantages; product consistency, yield, lower costs and more automation. This study
investigated the effects of four processing variables in the manufacture of Camembert
cheese using UF and their impact on cheese quality. Using an incomplete block
design, sixteen unique treatments were produced with combined processing variables
(high-fat or low-fat; brine-salted or retentate-salted; acidified to pH 5.2 or pH 4.9; set
in tubular moulds and small moulds). The cheeses were matured for seven weeks at
4±1 ºC and were analysed for total solids, fat, salt, non-protein nitrogen (NPN) and
soluble nitrogen (SN) contents during the maturation period (seven weeks). Major
defects were evaluated by experienced cheese graders in the fourth week. pH was
measured and instrumental analysis was also conducted. Sensory evaluation on
consumer acceptance was also conducted in the fourth week.
All the cheese samples exhibited similar increases in rind and core pH, NPN/TN and
SN/TN ratios, and were generally characterised by thick rind and softness. The lowfat
cheese samples had significantly lower NPN/TN ratio and higher overall
acceptance in sensory evaluation. The salt content was also significantly higher. The
retentate-salted cheese samples had significantly lower NPN/TN ratios and more
defects in rind discolouration and deformation, and saltiness. The cheese samples
acidified to pH 5.2 had significantly lower NPN/TN ratios and fewer defects in rind
discolouration, softness, sourness, and bitterness. The cheese samples made using
tube moulds were significantly firmer with fewer defects in rind deformation, core
unevenness, and softness.
The level of fat and extent of acidification was found to have a profound effect on
cheese quality, and cheeses produced with low-fat retentate and/or acidified to pH 5.2
generally had superior shelf-life with lower levels of proteolysis. The preference of
the two salting methods may be debatable, but considering labour and time, retentatesalting
is preferable. Tube mould generally produced better cheese with fewer defects.