Writing in the journal Trends in Food Science & Technology, Brazilian scientists said the two emerging processing technologies could help maintain the functional properties of probiotics.
Because traditional thermal techniques can destroy the friendly bacteria, studies have been conducted to see if new technologies could do a better job. This work could potentially expand the food shelf space currently open to probiotics.
Promising technologies
Reviewing the literature relevant to processing probiotic milk products, the Brazilian scientists said: “The application of HP and PEF to develop dairy foods supplemented with probiotic cultures is promising.”
In addition to overcoming the problem of heat related damage, the scientists said these emerging technologies may have a positive impact on some quality parameters. For example, in probiotic yoghurts the scientists note that HP treatment may improve the texture, delivering firmer and thicker products.
And pulsed electric field techniques have been advanced as having significant potential for cheese manufacturing because studies have reported improvements in the coagulation properties of the milk, such as gel firmness and time of coagulation during cheese production.
Potential drawbacks
But drawbacks do remain to both these technologies. For example, equipment for high pressure processing remains expensive despite cost reductions over recent years.
In addition, some concerns remain about product quality. For example, the authors reference research that suggests PEF treatment may reduce tolerance to acid and bile in probiotic dairy products, potentially compromising their probiotic potential.
Beyond technical issues there is also the challenge of achieving consumer acceptance. Here, the authors underlined the importance of informing consumers about the benefits of using novel processing techniques and using clear and comprehensible language when doing so.
Comparing the two processing technologies explored in the review, the authors said: “In a first view, it is suggested that the yoghurt processed by HP supplemented with probiotic cultures seems to be the most suitable for commercialisation.
“This product already has a positive image by part of the consumers, and has a sense of health and nutritive, which can make the process of commercialisation more streamlined.”
In a final word, the authors said that to achieve a better understanding of the impact of HP and PEF on the survival of probiotics, “it is necessary to optimize the involved parameters in relation to each microbial strain used, as well as to verify the sensory acceptability of the processed final products.”
Source: Trends in Food Science & Technology
10.1016/j.tifs.2010.07.006
High Pressure Processing and Pulsed Electric Fields: potential use in probiotic dairy foods processing
Authors: Adriano G. da Cruz, Jose A.F. Faria, Susana M.I. Saad, Anderson S.Sant'Ana, Marcelo O. Cristianni