Валоризация остаточной йогуртной сыворотки при производстве молочной кислоты: оптимизированный процесс

Nansib, A.; Nansib, N.; Azzoug, A.; Abed, A.; Daba, Kh.; Boudrant, D.; Amirova, Eh.R.; Meledina, T.V.; Golovinskaya, O.V., St. Petersburg State National Reseach Univ. of Information Technology, Optical Design and Engineering

Valorization of residual yoghurt whey by lactic acid production: an optimized process | Валоризация остаточной йогуртной сыворотки при производстве молочной кислоты: оптимизированный процесс

2016

Waste valorization practices have attracted a significant amount of attention in recent years with the aim of managing waste in the most sustainable way. Food waste constitutes a largely under-exploited residue from which a variety of valuable chemicals can be derived. The operation in global yoghurt market frequently provokes the reject and withdrawn of yoghurt derivates out of shelf life. This work comprises a contribution on the valorisation of this high polluting waste of the dairy industry, based on the production of lactic acid using residual yoghurt whey as raw material. Response surface methodology (RSM) based on central composite design (CCD) was used to evaluate the effects of fermentation parameters for lactic acid production by Lactococcus lactis subsp. in batch experiments. The critical factors selected for the investigation were: sugars concentration (X1), yeast extract concentration (X2) and inoculum size (X3). The experimental results were fitted with a second order polynomial equation by a regression analysis, and the model could predict 93% of the variation. A maximum lactic acid production (6.80 g/l) was obtained under following optimal conditions: sugars concentration 57 g/l, yeast extract concentration 10.8 g/l and inoculum size 10%. Moreover, the maximum of lactic acid production predicted by the model was 6.61 g/l. These results confirmed the validity of the model, and the experimental values were quite close to the predicted values.

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