Concentrated Buffalo Whey as Substrate for Probiotic Cultures and as Source of Bioactive Ingredients: A Local Circular Economy Approach towards Reuse of Wastewaters

Abstract

Waste reduction and reuse is a crucial target of current research efforts. In this respect, the present study was focused on providing an example of local investment in a simple process configuration that converts whey into value-added compounds and allows recovery of a clean water stream. In particular, buffalo milk whey obtained during mozzarella manufacturing was ultrafiltered in-house on spiral membrane modules (20 kDa), and the two obtained fractions, namely the retentate and the permeate, provided by the dairy factory, were further processed during this work. The use of an additional nanofiltration step allowed the recovery of high-quality water to be reused in the production cycle (machine rinsing water within the facility) and/or in agriculture, also reducing disposal costs and the environmental impact. The ultrafiltration retentate, on the other hand, was spray-dried and the powder obtained was used as the main substrate for the cultivation of Lactobacillus fermentum, a widely studied probiotic with anti-inflammatory, immunomodulatory and cholesterol-lowering properties. In addition, the same sample was tested in vitro on a human keratinocytes model. Resuspended concentrated whey powder improved cell reparation rate in scratch assays, assisted through time-lapse video-microscopy. Overall these data support the potential of buffalo whey as a source of biologically active components and recyclable water in the frame of a local circular economy approach.

No Waste from Waste: Membrane-Based Fractionation of Second Cheese Whey for Potential Nutraceutical and Cosmeceutical Applications, and as Renewable Substrate for Fermentation Processes Development

“…To overcome this issue, various technological approaches have been employed to transform and exploit whey components [3]. In fact, by implementing innovative downstream and biotechnological processes, using membranes, rather than being viewed as a waste product whey may be considered a resource to obtain high added-value products [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Several methods, such as UF, NF, and ion exchange chromatography, have been used to concentrate and separate proteins and lactose from other components present in second cheese whey.…”

“…SCW, R100, R10, and RNF were also used as a main substrate for probiotic cultures. In fact, thanks to the carbon sources content (lactose, glucose, galactose) in addition to proteins (as reported in Table 1), all are potentially complete substrates for the cultivation of different microorganisms [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] and for the production of value-added chemicals (e.g., succinic acid, lactic acid), antimicrobial peptides, besides the biomass itself [27][28][29]. In the first trial reported in Figure 2, three different Lactobacillus strains were grown on an SCW-based medium, showing that after 17 h, a comparable viability for L. rhamnosus IMC501and L. brevis SP-48 was obtained whereas a far lower concentration of viable cells was found for L. fermentum.…”

“…The downstream process reported by Alfano and collaborators was slightly modified [21]. After the microfiltration process, SCW was first concentrated on 100 kDa membranes, and the permeate obtained was treated on 10 kDa membranes.…”

Whey filtration: a review of products, application, and pretreatment with transglutaminase enzyme

“…41 The use of membranes not only reduces costs by enabling water reuse and recovery during processing but also assists in compliance with environmental regulations. 42 The streams of demineralized water from whey permeate can be used for primary rinsing in clean-in-place (CIP) cleaning processes, as well as for domestic use in toilets or truck washing in industries. However, for industrial use, specific parameters must be followed to ensure portability and avoid any microbiological risks.…”

“…The use of membranes not only reduces costs by enabling water reuse and recovery during processing but also assists in compliance with environmental regulations 42 …”