Lead researcher Ana Madureira of Porto’s Universidade Catolica Portuguesa proposed whey cheese as a carrier for probiotics in 2005, as it has a relatively high pH, fat content and mechanical consistency, as well as typically low oxygen levels. These conditions all together have been seen to provide extra protection to the bacteria during storage and in the gastrointestinal tract.
Madureira and her team write in the new paper, published in the Journal of Food Science, that whey cheeses have already “met with technological and preliminary commercial success”.
The new paper describes attempts to optimise the manufacture of probiotic whey cheeses, which could eventually provide a new commercial use for whey, a by-product of conventional cheese manufacture.
The researchers ran a total of 16 experiments, with processing parameters being the fractional addition of bovine milk to feedstock whey, homogenisation time, and storage time of whey cheese.
The probiotic whey cheeses matrices were inoculated with Lactobacissus casei LAFTI L126, a freeze-dried concentrated started culture obtained from DSM in Australia (sold as DELVO-PRO at 10 per cent.
Control whey cheeses matrices had skim milk added to them, that had previously been acidified with lactic acid at the same level.
All the whey cheeses were stored at 7 degrees Celsius for up to 14 days.
Chemical and sensory analyses were then carried out, as well as rheological characterisation and textural profiling.
The team found the main differences were due to storage time and the fractional addition of milk were seen to have the most impact.
“The differences found between probiotic and control matrices are mainly in terms of pH, hardness, springiness, and physicochemical parameters—which can be attributed, directly or indirectly, to addition of the probiotic strain and consequently to its metabolism in situ,” they wrote.
The best time for consumption was within 9 days of manufacture, and addition of milk at a rate of 10 to 15 percent, and homogenisation for five minutes led to the best texture and organoleptic properties.
Journal of Food Science Vol 76, Nr 2, 2011
Title: Technological Optimisation of Manufacture of Probiotic Whey Cheese Matrices
Authors: Madureira, A; Brandao, T; Gomes, A; Pintado, M; Malcata, FX.