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Hofmann K, Hamel C. Screening and Scale-up of Nanofiltration Membranes for Concentration of Lactose and Real Whey Permeate. MEMBRANES 2023; 13:173. [PMID: 36837676 PMCID: PMC9962324 DOI: 10.3390/membranes13020173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
In dairy industry huge quantities of whey accumulate as a by-product. In particular the containing lactose was not produced profitably in the past. Thus, the trend goes towards modification and sustainable use of lactose for which a concentration step is required. Nanofiltration (NF) has shown to be a good choice since partial demineralization can be realized in parallel. Therefore, in this study, 10 commercial polymer NF membranes were studied in detail and systematically for their suitability to concentrate lactose, with the proviso of high flux and high to complete rejection. Preliminary trials were conducted with flat-sheet membranes and a lactose model solution and the influence of transmembrane pressure (TMP), temperature and lactose concentration was studied. Finally, results were evaluated by using spiral wound modules and real industrial whey permeate. The results offered that a membrane screening is essentially since no correlation between molecular weight cut-off (MWCO) and permeate flow could be found. The conclusions found for the lactose model solution were in good agreement with the whey permeate, but as the ions contribute to the osmotic pressure of the feed the deviations increase in the course of concentration since ions are also partly retained.
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Affiliation(s)
- Katrin Hofmann
- Applied Biosciences and Process Engineering, Anhalt University of Applied Sciences, Bernburger Straße 55, 06366 Koethen, Germany
| | - Christof Hamel
- Applied Biosciences and Process Engineering, Anhalt University of Applied Sciences, Bernburger Straße 55, 06366 Koethen, Germany
- Institute of Process Engineering, Otto von Guericke University, Universitaetsplatz 2, 39109 Magdeburg, Germany
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Cyclic Production of Galacto-Oligosaccharides through Ultrafiltration-Assisted Enzyme Recovery. Processes (Basel) 2023. [DOI: 10.3390/pr11010225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Galacto-oligosaccharides (GOS) are prebiotics manufactured enzymatically from lactose as substrate. The growing GOS market facilitates the valorization of dairy by-products which represent cheap and abundant sources of lactose. Large-scale GOS production typically employs soluble enzymes in batch reactors that are commonly associated with low enzyme usability and, therefore, high operational expenditures. In this study, we investigate the possibility of recovering enzymes by ultrafiltration (UF) and reusing them in repeated reaction steps. The proposed process scheme included 24 h batch reaction steps with Biolacta N5, a commercial enzyme preparation of Bacillus circulans origin. The reaction steps were followed by UF steps to separate the carbohydrate products from the enzymes by applying a volume concentration factor of 8.6. Then, the collected biocatalysts were reused for repeated cycles by adding fresh lactose. Enzyme losses were quantified with a direct method by analyzing the underlying relationship between reaction rates and enzyme dosage obtained from additional experiments conducted with known enzyme loads. Within five cycles, the enzyme activity declined gradually from 923 to 8307 U·kg−1, and the half-life was estimated as ca. 15.3 h. The outcomes of this study may serve as a basis for further optimization of the reported process scheme with enhanced enzyme usability.
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Maráz A, Kovács Z, Benjamins E, Pázmándi M. Recent developments in microbial production of high-purity galacto-oligosaccharides. World J Microbiol Biotechnol 2022; 38:95. [PMID: 35441950 PMCID: PMC9021073 DOI: 10.1007/s11274-022-03279-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/03/2022] [Indexed: 12/30/2022]
Abstract
Galacto-oligosaccharides (GOS) are used as prebiotic ingredients in various food and pharmaceutical formulations. Currently, production of GOS involves the enzymatic conversion of lactose by transgalactosylation using β-galactosidase. The purity of the resulting product is low, typically limited to up to 55% GOS on total carbohydrate basis due to the presence of non-reacted lactose, and the formation of by-products glucose and galactose. In industrial practice high-purity GOS is manufactured by removing the unwanted mono- and disaccharides from raw GOS with simulated moving bed (SMB) chromatography. This purification step is associated with high processing cost that increases the price of pure GOS and limits its marketability. The last decades have witnessed a growing interest in developing competitive biotechnological processes that could replace chromatography. This paper presents a comprehensive review on the recent advancements of microbial GOS purification, a process commonly referred to as selective fermentation or selective metabolism. Purification strategies include: (i) removal of glucose alone or together with galactose by lactose negative yeast species, that typically results in purity values below 60% due to remaining lactose; (ii) removal of both mono- and disaccharides by combining the fast monosaccharide metabolizing capacity of some yeast species with efficient lactose consumption by certain lactose positive microbes, reaching GOS purity in the range of 60-95%; and (iii) the application of selected strains of Kluyveromyces species with high lactose metabolizing activity to achieve high-purity GOS that is practically free from lactose and monosaccharides.
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Affiliation(s)
- Anna Maráz
- Department of Food Microbiology, Hygiene and Safety, Institute of Food Science and Technology, Hungarian University of Agriculture and Life Sciences, H-1118, Somlói út 14-16, Budapest, Hungary.
| | - Zoltán Kovács
- Department of Food Process Engineering, Institute of Food Science and Technology, Hungarian University of Agriculture and Life Sciences, Budapest, Hungary
| | | | - Melinda Pázmándi
- Department of Food Microbiology, Hygiene and Safety, Institute of Food Science and Technology, Hungarian University of Agriculture and Life Sciences, H-1118, Somlói út 14-16, Budapest, Hungary
- Department of Food Process Engineering, Institute of Food Science and Technology, Hungarian University of Agriculture and Life Sciences, Budapest, Hungary
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Agri-Food Industry Waste as Resource of Chemicals: The Role of Membrane Technology in Their Sustainable Recycling. SUSTAINABILITY 2022. [DOI: 10.3390/su14031483] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The agri-food sector generates substantial quantities of waste material on farm and during the processing of these commodities, creating serious social and environmental problems. However, these wastes can be resources of raw material for the production of valuable chemicals with applications in various industrial sectors (e.g., food ingredients, nutraceuticals, bioderived fine chemicals, biofuels etc.). The recovery, purification and biotransformation of agri-food waste phytochemicals from this microbial spoilage-prone, complex agri-food waste material, requires appropriate fast pre-treatment and integration of various processes. This review provides a brief summary and discussion of the unique advantages and the importance of membrane technology in sustainable recycling of phytochemicals from some of the main agri-food sectors. Membrane-based pressure -driven processes present several advantages for the recovery of labile compounds from dilute streams. For example, they are clean technologies that can operate at low temperature (20–60 °C), have low energy requirements, there is no need for additional chemicals, can be quite automated and electrifiable, and have low space requirements. Based on their permselective properties based on size-, shape-, and charge-exclusion mechanisms, membrane-based separation processes have unpaired efficiency in fractionating biological components while presenting their properties. Pressure-driven membrane processes, such as microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF), as well as other advanced membrane-based processes such as membrane bioreactors (MBR), membrane emulsification (ME) and membrane distillation (MD), are presented. The integration of various membrane technologies from the initial recovery of these phytochemicals (MF, UF, NF) to the final formulation (by ME) of commercial products is described. A good example of an extensively studied agri-food stream is the olive processing industry, where many different alternatives have been suggested for the recovery of biophenols and final product fabrication. Membrane process integration will deliver in the near future mature technologies for the efficient treatment of these streams in larger scales, with direct impact on the environmental protection and society (production of compounds with positive health effects, new job creation, etc.). It is expected that integration of these technologies will have substantial impact on future bio-based societies over forthcoming decades and change the way that these chemicals are currently produced, moving from petrochemical-based linear product fabrication to a sustainable circular product design based in agri-food waste biomass.
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Pázmándi M, Kovács Z, Maráz A. Potential of Lactobacillus strains for the production of fermented functional beverages enriched in galacto-oligosaccharides. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111097] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Cao T, Pázmándi M, Galambos I, Kovács Z. Continuous Production of Galacto-Oligosaccharides by an Enzyme Membrane Reactor Utilizing Free Enzymes. MEMBRANES 2020; 10:E203. [PMID: 32867283 PMCID: PMC7560224 DOI: 10.3390/membranes10090203] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/14/2020] [Accepted: 08/24/2020] [Indexed: 11/16/2022]
Abstract
Galacto-oligosaccharides (GOS) are prebiotic compounds widely used for their health-promoting effects. Conventionally, GOS is produced by the enzymatic conversion of lactose in stirred tank reactors (STR). The high operational costs associated with enzyme inactivation and removal might be reduced by the application of enzyme membrane reactors (EMR). In this study, we aimed to assess the potential of continuous GOS production by EMR using soluble Biolacta N5, a Bacillus circulans-derived commercial enzyme preparation. The steady-state performance of the EMR equipped with an ultrafiltration module was investigated as function of residence time (1.1-2.8 h) and enzyme load (17-190 U·g-1) under fixed operational settings of temperature (50 °C), pH (6.0), lactose feed concentration (300 g·kg-1), and recirculation flow-rate (0.18 m3·h-1). Results indicate that the yield of oligosaccharides with higher degree of polymerization (DP3-6) in STR (approx. 38% on total carbohydrate basis) exceeds that measured in EMR (ranging from 24% to 33%). However, a stable catalytic performance without a significant deterioration in product quality was observed when operating the EMR for an extended period of time (> 120 h). Approx. 1.4 kg of DP3-6 was produced per one gram of crude enzyme preparation over the long-term campaigns, indicating that EMR efficiently recovers enzyme activity.
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Affiliation(s)
- Teng Cao
- Department of Food Engineering, Szent István University, 1118 Budapest, Hungary; (T.C.); (M.P.)
| | - Melinda Pázmándi
- Department of Food Engineering, Szent István University, 1118 Budapest, Hungary; (T.C.); (M.P.)
- Department of Microbiology and Biotechnology, Szent István University, 1118 Budapest, Hungary
| | - Ildikó Galambos
- Soós Ernő Water Technology Research and Development Center, University of Pannonia, 8200 Nagykanizsa, Hungary;
| | - Zoltán Kovács
- Department of Food Engineering, Szent István University, 1118 Budapest, Hungary; (T.C.); (M.P.)
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Pázmándi M, Kovács Z, Balga E, Kovács M, Maráz A. Production of high-purity galacto-oligosaccharides by depleting glucose and lactose from galacto-oligosaccharide syrup with yeasts. Yeast 2020; 37:515-530. [PMID: 32602234 DOI: 10.1002/yea.3507] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/28/2020] [Accepted: 06/22/2020] [Indexed: 11/06/2022] Open
Abstract
Galacto-oligosaccharides (GOS) are prebiotic compounds, widely used as ingredients in various food, nutraceutical and pharmaceutical products. Enzymatic synthesis of GOS results in low-purity products that contain high amounts of glucose and lactose beside the valuable GOS. In this study, a systematic approach was used to develop yeast-based fermentation strategies to purify crude GOS. Potentially applicable yeast strains were identified based on an extensive search in literature databases followed by a series of laboratory-scale fermentation tests. Single- and two-step fermentation processes were designed for the removal of glucose alone or together with lactose from crude GOS syrup. Single-step fermentation trials with two strains of previously unreported species, Cyberlindnera jadinii NCAIM Y.00499 and Kluyveromyces nonfermentans NCAIM Y.01443, resulted in purified products free of both glucose and ethanol from a crude GOS syrup diluted to 15 and 10 w/v%, respectively. Simultaneous removal of glucose and lactose was achieved by Kluyveromyces marxianus DMB Km-RK in a single-step fermentation process with a yield of 97.5% and final purity of 100%. A two-step fermentation approach was designed to allow conversion of a glucose-free product into a high-purity GOS by removing glucose with C. jadinii Y.00499 in the first step, and lactose by Kluyveromyces lactis DMB Kl-RK in the second step, resulting in a final product with a yield of 100% and a final purity of 92.1%. These results indicate that the selected nonconventional yeasts are promising candidates for the removal of non-GOS components from commercial crude GOS products by selective fermentation.
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Affiliation(s)
- Melinda Pázmándi
- Department of Microbiology and Biotechnology, Szent István University, Budapest, Hungary.,Department of Food Process Engineering, Faculty of Food Science, Szent István University, Budapest, Hungary
| | - Zoltán Kovács
- Department of Food Process Engineering, Faculty of Food Science, Szent István University, Budapest, Hungary
| | - Edina Balga
- Department of Microbiology and Biotechnology, Szent István University, Budapest, Hungary
| | - Mónika Kovács
- Department of Microbiology and Biotechnology, Szent István University, Budapest, Hungary
| | - Anna Maráz
- Department of Microbiology and Biotechnology, Szent István University, Budapest, Hungary
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