Bingjie Hu, Faith Bernadette A. Descallar, Shingo Matsukawa
Pure and mixed κ- and ι-carrageenan (CR) were studied by rheology and solid-state nuclear magnetic resonance (NMR) (SSNMR), combining bulk viscoelasticity and microscopic local molecular conformational information for understanding the morphological arrangement of the microstructure of gel network. Independent formation of double helices of κ- or ι-CR was confirmed by rheological data, and two possible models, microphase separation and interpenetrating network (IPN), were also proposed. The cross-polarization magic angle spinning (CPMAS) measurements by SSNMR for mixed gels showed the “new peak” at 95.4 ppm, which was supposed to be mainly composed of concentrated κ-CR chains in phase separation model or the κ-CR with changed conformation due to dense interlacing in the IPN model, in both of which the co-aggregates of κ- and ι-helices may also be incorporated. The molecular dynamic of anomeric carbon of anhydrogalactopyranose (A1-C) region was evaluated by variable contact time (VCT) measurements via fitting for the deconvolution generated “new peak,” pure κ-CR at 93.9 ppm and ι-CR 91.8 ppm. The obtained T1ρ described the degree of homogeneity over a few nanometers and was therefore used to calculate the scale of homogeneity of mixture CR gels to be 1–3 nm. SSNMR was testified to be a practical method for research on multiphase hydrocolloids.
{"title":"Microstructure of mixed κ- and ι-carrageenan gels viewed by rheology and solid-state NMR","authors":"Bingjie Hu, Faith Bernadette A. Descallar, Shingo Matsukawa","doi":"10.1111/1750-3841.70059","DOIUrl":"https://doi.org/10.1111/1750-3841.70059","url":null,"abstract":"<p>Pure and mixed κ- and ι-carrageenan (CR) were studied by rheology and solid-state nuclear magnetic resonance (NMR) (SSNMR), combining bulk viscoelasticity and microscopic local molecular conformational information for understanding the morphological arrangement of the microstructure of gel network. Independent formation of double helices of κ- or ι-CR was confirmed by rheological data, and two possible models, microphase separation and interpenetrating network (IPN), were also proposed. The cross-polarization magic angle spinning (CPMAS) measurements by SSNMR for mixed gels showed the “new peak” at 95.4 ppm, which was supposed to be mainly composed of concentrated κ-CR chains in phase separation model or the κ-CR with changed conformation due to dense interlacing in the IPN model, in both of which the co-aggregates of κ- and ι-helices may also be incorporated. The molecular dynamic of anomeric carbon of anhydrogalactopyranose (A1-C) region was evaluated by variable contact time (VCT) measurements via fitting for the deconvolution generated “new peak,” pure κ-CR at 93.9 ppm and ι-CR 91.8 ppm. The obtained <i>T<sub>1ρ</sub></i> described the degree of homogeneity over a few nanometers and was therefore used to calculate the scale of homogeneity of mixture CR gels to be 1–3 nm. SSNMR was testified to be a practical method for research on multiphase hydrocolloids.</p>","PeriodicalId":193,"journal":{"name":"Journal of Food Science","volume":"90 2","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ning Wang, Weizhe Wang, Yufeng Su, Jinglin Zhang, Baoguo Sun, Nasi Ai
Immobilized lipases have received great attention in food, environment, medicine, and other fields due to their easy separation, high stability (temperature, pH), and high storage properties. After immobilization, lipase transforms from a homogeneous to a heterogeneous state, making it easier to recover from the reaction substrate and achieve recycling, which is in line with the concept of green chemistry and reduces protein contamination in the product. There are various materials for enzyme immobilization, including polysaccharides from natural sources, inorganic compounds, carbon nanotubes, metal–organic framework materials, and so forth. Magnetic immobilization carriers have been widely studied due to their ability to achieve separation by adding a magnetic field. Its immobilization method can be simply divided into two categories: physical action (adsorption, embedding) and chemical binding (covalent, cross-linking). Some studies mainly discuss the immobilization support materials, immobilization methods, and applications of immobilized lipases in food. On this basis, our review also focuses on the changes in crosslinking agents for immobilized lipases, different methods to promote immobilization, new trends in the study of immobilized lipases, and proposes prospects for immobilized lipase research in the food industry.
{"title":"The current research status of immobilized lipase performance and its potential for application in food are developing toward green and healthy direction: A review","authors":"Ning Wang, Weizhe Wang, Yufeng Su, Jinglin Zhang, Baoguo Sun, Nasi Ai","doi":"10.1111/1750-3841.70038","DOIUrl":"https://doi.org/10.1111/1750-3841.70038","url":null,"abstract":"<p>Immobilized lipases have received great attention in food, environment, medicine, and other fields due to their easy separation, high stability (temperature, pH), and high storage properties. After immobilization, lipase transforms from a homogeneous to a heterogeneous state, making it easier to recover from the reaction substrate and achieve recycling, which is in line with the concept of green chemistry and reduces protein contamination in the product. There are various materials for enzyme immobilization, including polysaccharides from natural sources, inorganic compounds, carbon nanotubes, metal–organic framework materials, and so forth. Magnetic immobilization carriers have been widely studied due to their ability to achieve separation by adding a magnetic field. Its immobilization method can be simply divided into two categories: physical action (adsorption, embedding) and chemical binding (covalent, cross-linking). Some studies mainly discuss the immobilization support materials, immobilization methods, and applications of immobilized lipases in food. On this basis, our review also focuses on the changes in crosslinking agents for immobilized lipases, different methods to promote immobilization, new trends in the study of immobilized lipases, and proposes prospects for immobilized lipase research in the food industry.</p>","PeriodicalId":193,"journal":{"name":"Journal of Food Science","volume":"90 2","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1750-3841.70038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}