Cheese whey permeate as a precursor of lactose-free, galactose-rich bioproducts: an approach for optimization and application

Abstract

Under specific conditions, the fermentation of whey permeate (WP) by Brettanomyces claussenii can create bioproducts with high galactose concentrations and potential functionalities. The aims of this research are to optimize the fermentation of WP by B. claussenii using response surface methodology to maximize the production of ethanol and galactose, and to characterize various products obtained with this approach. For this purpose, five fermentation factors were studied to determine their impacts on ethanol and galactose: temperature (20 - 40°C), substrate concentration (5 - 15%TS), lactase enzyme/substrate ratio (0 - 40 IU/ g lactose), inoculation level (6 - 8 log cfu/mL), and time (6 - 30 days). Linear models, containing quadratic and interaction effects, were built for the optimization of both responses. Optimal levels were predicted for the maximum obtainment of ethanol and galactose simultaneously, which utilized the following parameters: 15%TS, 37 IU / g lactose, 28°C, 7.5 log cfu/mL, and 30 days, which together were predicted to produce 4.0%v/v ethanol and 51 g/L galactose in the final product. These parameters were then applied to 18-L fermentations, and the resulting fermentates were processed via distillation and freeze-drying. As a result, four product streams were obtained: a fermented product with 3.4%v/v ethanol and 56 g/L galactose; a 45%v/v ethanol distillate; a galactose-rich drink base (63 g/L); and a galactose-rich powder (55%w/w). These results demonstrate that it is possible to maximize the production of ethanol and galactose from the fermentation of WP and to design manufacturing processes based on these optimization models, to develop novel, potentially functional bioproducts from this stream.

Leveraging Milk Permeate Fermentation to Produce Lactose-Free, Low-In-Glucose, Galactose-Rich Bioproducts: Optimizations and Applications

“…First, aliquots of 1.4 mL of the starter were pipetted into 15 mL centrifuge tubes to attain an inoculation level of 6.5 log cfu/mL. This inoculation level was reported as optimal for galactose retention by Rivera Flores, et al [24]. All tubes were centrifuged at 3220× g for 2 min, their DME supernatants discarded, and the cell pellets resuspended in 10 mL of MP solution.…”

“…Three factors-temperature, inoculation level, and time-were studied at the levels presented in Table 2. The range of temperature included optimal conditions for this strain in WP reported in a previous study [24], and the ranges of inoculation level and time were determined by the findings of the previous section. A central composite design was built via response surface methodology, considering the following responses: galactose retention, final glucose, and ethanol production.…”

“…Jencarelli [17] studied these variables in synthetic media to simulate the scenarios of different dairy coproducts. At the same time, Rivera Flores, et al [24] presented ethanol and galactose optimization results in cheese whey permeate (WP). The results from these studies showed that it is possible to approximate and maximize the amount of galactose and galactose-ethanol during the respective aerobic and anaerobic fermentations with this organism, respectively.…”

“…The results from these studies showed that it is possible to approximate and maximize the amount of galactose and galactose-ethanol during the respective aerobic and anaerobic fermentations with this organism, respectively. In addition, distillation and freeze-drying were proposed to combine with fermentation to generate multiple food and ingredients derived from this approach [24].…”

The Brønsted-Lewis acid sites in Metal-organic framework nanozymes for cooperatively enhancing the hydrolysis of lactose

“…Therefore, the hydrolysis of lactose in dairy processing is of great signi cance (Jansson-Knodell, et al, 2020; Perets, et al, 2014). Natural lactase is widely used in dairy processing (Flores, et al, 2023;Ugidos-Rodriguez, et al, 2018). However, the activity of natural lactase is greatly in uenced by external conditions, which lead to inherent drawbacks, such as high preparation costs and poor stability for industrial production (Nussinovitch, et al, 2012;Xu, et al, 2021).…”