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Miao M, Li S, Yang S, Yan Q, Xiang Z, Jiang Z. Engineering the β-galactosidase from Aspergillus oryzae for making lactose-free and no-sugar-added yogurt. J Dairy Sci 2024:S0022-0302(24)00769-0. [PMID: 38670341 DOI: 10.3168/jds.2023-24310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 03/18/2024] [Indexed: 04/28/2024]
Abstract
Yogurt usually contains 5-7% sugar and 3-5% lactose. As β-galactosidases can hydrolyze lactose and improve sweetness, they have the potential to produce lactose-free (LF) and no-sugar-added (NSA) yogurt. In this study, β-galactosidase AoBgal35A from Aspergillus oryzae was engineered by site-saturation mutagenesis. Results of 19 variants of T955 residue showed that lactose hydrolysis rate of T955R-AoBgal35A was up to 90.7%, much higher than 78.5% of the wild type. Moreover, the optimal pH of T955R-AoBgal35A was shifted from pH 4.5 to pH 5.5 and the optimal temperature decreased from 60°C to 50°C. The mutant T955R-AoBgal35A was successfully expressed in Komagatella pastoris, which produced extracellularly 4528 U/mL of β-galactosidase activity. The mutant T955R-AoBgal35A was used to produce LF yogurt. Streptococcus thermophilus counts of LF yogurt increased from 7.9 to 9.5 lg cfu/g, significantly higher than that of the control group (8.9 lg cfu/g). Residual lactose content of LF yogurt was 0.13%, meeting the requirement of "lactose-free" label (<0.5%, GB 28050-2011, China). Furthermore, sugar in yogurt was replaced by whey powder to produce LF-NSA yogurt. The optimal addition content of whey powder was 7.5%. The texture, WHC and titratable acidity of LF and LF-NSA yogurt achieved good stability during the shelf life. Therefore, this study provides an insight for technological implications of β-galactosidases in the dairy industry.
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Affiliation(s)
- Miao Miao
- Key Laboratory of China National Light Industry and Food Bioengineering, College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Shusen Li
- Key Laboratory of China National Light Industry and Food Bioengineering, College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, China; Mengniu Hi-tech Dairy Product Beijing Co., Ltd., Beijing 101100, China
| | - Shaoqing Yang
- Key Laboratory of China National Light Industry and Food Bioengineering, College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Qiaojuan Yan
- College of Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Zhixuan Xiang
- Key Laboratory of China National Light Industry and Food Bioengineering, College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Zhengqiang Jiang
- Key Laboratory of China National Light Industry and Food Bioengineering, College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, China; Food Laboratory of Zhongyuan, Luohe 462300, China.
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Wang A, Zhong Q. Drying of probiotics to enhance the viability during preparation, storage, food application, and digestion: A review. Compr Rev Food Sci Food Saf 2024; 23:e13287. [PMID: 38284583 DOI: 10.1111/1541-4337.13287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/18/2023] [Accepted: 12/11/2023] [Indexed: 01/30/2024]
Abstract
Functional food products containing viable probiotics have become increasingly popular and demand for probiotic ingredients that maintain viability and stability during processing, storage, and gastrointestinal digestions. This has resulted in heightened research and development of powdered probiotic ingredients. The aim of this review is to overview the development of dried probiotics from upstream identification to downstream applications in food. Free probiotic bacteria are susceptible to various environmental stresses during food processing, storage, and after ingestion, necessitating additional materials and processes to preserve their activity for delivery to the colon. Various classic and emerging thermal and nonthermal drying technologies are discussed for their efficiency in preparing dehydrated probiotics, and strategies for enhancing probiotic survival after dehydration are highlighted. Both the formulation and drying technology can influence the microbiological and physical properties of powdered probiotics that are to be characterized comprehensively with various techniques. Furthermore, quality control during probiotic manufacturing and strategies of incorporating powdered probiotics into liquid and solid food products are discussed. As emerging technologies, structure-design principles to encapsulate probiotics in engineered structures and protective materials with improved survivability are highlighted. Overall, this review provides insights into formulations and drying technologies required to supplement viable and stable probiotics into functional foods, ensuring the retention of their health benefits upon consumption.
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Affiliation(s)
- Anyi Wang
- Department of Food Science, University of Tennessee, Knoxville, Tennessee, USA
- International Flavors and Fragrances, Palo Alto, California, USA
| | - Qixin Zhong
- Department of Food Science, University of Tennessee, Knoxville, Tennessee, USA
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Journey of the Probiotic Bacteria: Survival of the Fittest. Microorganisms 2022; 11:microorganisms11010095. [PMID: 36677387 PMCID: PMC9861974 DOI: 10.3390/microorganisms11010095] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 01/03/2023] Open
Abstract
This review aims to bring a more general view of the technological and biological challenges regarding production and use of probiotic bacteria in promoting human health. After a brief description of the current concepts, the challenges for the production at an industrial level are presented from the physiology of the central metabolism to the ability to face the main forms of stress in the industrial process. Once produced, these cells are processed to be commercialized in suspension or dried forms or added to food matrices. At this stage, the maintenance of cell viability and vitality is of paramount for the quality of the product. Powder products requires the development of strategies that ensure the integrity of components and cellular functions that allow complete recovery of cells at the time of consumption. Finally, once consumed, probiotic cells must face a very powerful set of physicochemical mechanisms within the body, which include enzymes, antibacterial molecules and sudden changes in pH. Understanding the action of these agents and the induction of cellular tolerance mechanisms is fundamental for the selection of increasingly efficient strains in order to survive from production to colonization of the intestinal tract and to promote the desired health benefits.
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Eha K, Kaleda A, Menert A, Laos K. Water sorption behaviour of commercial furcellaran. Heliyon 2022; 8:e11056. [PMID: 36325138 PMCID: PMC9618988 DOI: 10.1016/j.heliyon.2022.e11056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/27/2022] [Accepted: 10/07/2022] [Indexed: 11/06/2022] Open
Abstract
Water sorption isotherms are important tool for designing the technological processes and predicting stability and shelf life of food. The aim of the work was to determine the water sorption isotherms of commercial furcellaran at different temperatures (20, 35 and 50 °C) using a gravimetric method under different levels of relative humidity (19–95%). The experimental data obtained have been interpreted in the terms of various isotherm models and it was found that the best results were obtained with the Peleg model (P < 2.1%; RSME <0.01; R2 = 1.00). The obtained isotherms followed the type II pattern and, in all cases, the sorption capacity increased with increasing water activity and decreased with increasing temperature. The maximum net isosteric heat for adsorption and desorption was 938.9 and 988.6 J g −1, respectively, at an equilibrium moisture content of 0.05 gw gdb−1. The net isosteric heat of sorption decreased exponentially with increasing moisture content and approached zero at 0.26 gw gdb−1 for adsorption and 0.32 gw gdb−1 for desorption. The developed mathematical relationships can be used to optimize the drying processes and storage conditions of furcellaran. Moisture sorption isotherms of furcellaran were determined. The optimal isotherm model for furcellaran is the Peleg model. An equation for the calculation of the net isosteric heat of the sorption of furcellaran was developed.
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Affiliation(s)
- Kairit Eha
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Aleksei Kaleda
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia
| | - Anne Menert
- Institute of Molecular and Cell Biology, University of Tartu, Ülikooli 18, 50090 Tartu, Estonia
| | - Katrin Laos
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia,Corresponding author.
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