Food Safety of Functional Neoglycoproteins Prepared by Covalent Attachment of Galactomannan to Food Proteins

Soichiro Nakamura,Kazumi Dokai,Megumi Matsuura,Junya Hata,Hiroki Saeki 한국식품영양과학회 2002 Preventive Nutrition and Food Science Vol.7 No.2

Hen egg-white lysozyme, ovalbumin, egg-yolk phosvitin, acid-precipitated soy protein, αs1 milk casein were covalently linked with galactomannan through a controlled dry-heating at 60℃ under 79% relative humidity without any chemical reagent. Neoglycosylation by the covalent binding of polysaccharide chains brought a significant improvement into the surface functionalities of food proteins. Excellent emulsifying properties, foaming properties were observed in all protein-galactomannan conjugates. Bacterial mutagenesis tests, animal dose test were done to evaluate the food safety of the protein-galactomannan conjugates. The neoglycoproteins were negative for Ames test using Salmonella typhimurium TA100 (hisG46), TA98 (hisD3052) strains,, rec-assay using Bacillus subtilis H17 (rec^-), M45 (rec^+) strains. All substances were also nontoxic for oral administration to rats. LD_(50)’s of these substances were all more than 7.5 g/kg body-weight of rat. No effect was also observed in the weight increases, the concentrations of total cholesterol, triglyceride, phospholipids in blood serum of the administrated rats with 7.5 g/kg conjugates. Thus, Maillard-type proteinpolysaccharide conjugates prepared by covalent attachment of galactomannan to food proteins were proposed to be useful as a safe functional biopolymer in this study.

Food Safety of Functional Neoglycoproteins Prepared by Covalent Attachment of Galactomannan to Food Proteins

Nakamura, Soichiro,Dokai, Kazumi,Matsuura, Megumi,Hata, Junya,Saeki, Hiroki The Korean Society of Food Science and Nutrition 2002 Preventive Nutrition and Food Science Vol.7 No.2

Hen egg-white lysozyme, ovalbumin, egg-yolk phosvitin, acid-precipitated soy protein and $\alpha$$_{sl}$ milk casein were covalently linked with galactomannan through a controlled dry-heating at 6$0^{\circ}C$ under 79% relative humidity without any chemical reagent. Neoglycosylation by the covalent binding of polysaccharide chains brought a significant improvement into the surface functionalities of food proteins. Excellent emulsifying properties and foaming properties were observed in all protein-galactomannan conjugates. Bacterial mutagenesis tests and animal dose test were done to evaluate the food safety of the protein-galactomannan conjugates. The neo-glycoproteins were negative for Ames test using Salmonella typhimurium TA100 (hisG46) and TA98 (hisD3052) strains, and rec-assay using Bacillus subtilis Hl7 (rec) and M45 (re $c^{+}$) strains. All substances were also nontoxic for oral administration to rats. L $D_{50}$ 's of these substances were all more than 7.5 g/kg body-weight of rat. No effect was also observed in the weight increases and the concentrations of total cholesterol, triglyceride and phospholipids in blood serum of the administrated rats with 7.5 g/kg conjugates. Thus, Maillard-type protein-polysaccharide conjugates prepared by covalent attachment of galactomannan to food proteins were proposed to be useful as a safe functional biopolymer in this study.y.

Improving the Surface Functionality of Curdlan by Conjugation with Unfolding Protein through Naturally Occurring Maillard Reaction

Nakamura, Soichiro,Ogawa, Masahiro,Saeki, Hiroki,Saito, Masayoshi,Miyasaka, Satoko,Hata, Junya,Adachi, Naoko,Hwang, Jae-Kwan The Korean Society of Food Science and Nutrition 2000 Preventive Nutrition and Food Science Vol.5 No.4

Protein conjugation of curdlan belonging to $\beta$-1, 3-glucan was carried out to improve it surface functionalities. The glucan was mixed with phosvitin, {TEX}$$\alpha$_{s}${/TEX}-casein, lysozyme or ovalbumin, respectively. The mixture was freeze-dried, and he resulting powder was incubated at 6$0^{\circ}C$ and 79% relative humidity for 12 days in order to generate a controlled Maillard reaction between curdlan and proteins. conjugation with unfolding proteins, i.e., phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein, drastically increased the solubility of the glucan, whereas lysozyme and ovalbmin did not. The solubility in water of curdlan was 3.44% for the phosvitin conjugate and 1.09% for the {TEX}$$\alpha$_{s}${/TEX}-casein conjugate. SDS-slab polyacrylamide gel electrophoresis showed that curdlan was solubilized due to covalent binding with phosvitin. Emulsifying properties of curdlan were substantially improved by the conjugation with phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein. Emulsion stability of the curdlan-phosvitin conjugate was about 2.9 times greater than that of the curdlan-phosvitin mixture.

Development of Dilated Esophagus, Sigmoid Esophagus, and Esophageal Diverticulum in Patients With Achalasia: Japan Achalasia Multicenter Study

Hiroki Sato,Yusuke Fujiyoshi,Hirofumi Abe,Hironari Shiwaku,Junya Shiota,Chiaki Sato,Hiroyuki Sakae,Masaki Ominami,Yoshitaka Hata,Hisashi Fukuda,Ryo Ogawa,Jun Nakamura,Tetsuya Tatsuta,Yuichiro Ikebuchi 대한소화기 기능성질환∙운동학회 2022 Journal of Neurogastroenterology and Motility (JNM Vol.28 No.2

Background/AimsPatients with achalasia-related esophageal motility disorders (AEMDs) frequently present with dilated and sigmoid esophagus, and develop esophageal diverticulum (ED), although the prevalence and patients characteristics require further elucidation. MethodsWe conducted a multicenter cohort study of 3707 patients with AEMDs from 14 facilities in Japan. Esophagography on 3682 patients were analyzed. ResultsStraight (n = 2798), sigmoid (n = 684), and advanced sigmoid esophagus (n = 200) were diagnosed. Multivariate analysis revealed that long disease duration, advanced age, obesity, and type I achalasia correlate positively, whereas severe symptoms and integrated relaxation pressure correlate negatively with development of sigmoid esophagus. In contrast, Grade II dilation (3.5-6.0 cm) was the most common (52.9%), while grade III dilation (≥ 6 cm) was rare (5.0%). We found early onset, male, obesity, and type I achalasia correlated positively, while advanced age correlated negatively with esophageal dilation. Dilated and sigmoid esophagus were found mostly in types I and II achalasia, but typically not found in spastic disorders. The prevalence of ED was low (n = 63, 1.7%), and non-dilated esophagus and advanced age correlated with ED development. Patients with right-sided ED (n = 35) had a long disease duration (P = 0.005) with low integrated relaxation pressure values (P = 0.008) compared with patients with left-sided ED (n = 22). Patients with multiple EDs (n = 6) had lower symptom severity than patients with a single ED (P = 0.022). ConclusionsThe etiologies of dilated esophagus, sigmoid esophagus, and ED are considered multifactorial and different. Early diagnosis and optimal treatment of AEMDs are necessary to prevent these conditions.

Firmicutes in Gut Microbiota Correlate with Blood Testosterone Levels in Elderly Men

Matsushita Makoto,Fujita Kazutoshi,Motooka Daisuke,Hatano Koji,Hata Junya,Nishimoto Mitsuhisa,Banno Eri,Takezawa Kentaro,Fukuhara Shinichiro,Kiuchi Hiroshi,Pan Yue,Takao Toshifumi,Tsujimura Akira,Yach 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.3

Purpose: In males, testosterone levels have been implicated in various diseases. Recently, the influence of gut microbialderived compounds on host metabolism has become evident, and it has been suggested that some gut bacteria may be involved in testosterone metabolism. In the present study, we examined the relationship between testosterone levels and gut microbiota in elderly Japanese men. Materials and Methods: We collected samples from Japanese male subjects suspected of having prostate cancer and underwent prostate biopsies and excluded patients with positive biopsies to avoid the effect of prostate cancer on the gut microbiota. In total, 54 Japanese males with negative biopsy results were included in our study. The gut microbiota was analyzed by 16S rRNA gene sequencing of bacterial DNA extracted from rectal swabs. Gut microbiota compositions were compared between the two groups according to the level of serum testosterone (above or below 3.5 ng /mL). Results: The median age of the cohort was 71 years, and the quartile range was 67 to 73 years. We observed no significant difference in alpha or beta diversity, but some bacteria belonging to the phylum Firmicutes (Clostridiales, Turicibacter, and Gemella) were increased in the high testosterone group. Serum testosterone levels positively correlated with the relative amount of Firmicutes (rS=0.3323, p=0.0141), and the amount of Firmicutes affected serum testosterone levels independent of host factors (age, body mass index, triglyceride, and total cholesterol; β=0.770, p=0.0396). Conclusions: Some intestinal bacteria belonging to the phylum Firmicutes were associated with testosterone levels in elderly males. Therefore, the gut microbiota could affect testosterone metabolism in elderly males.

Subtype of Achalasia and Integrated Relaxation Pressure Measured Using the Starlet High-resolution Manometry System: A Multicenter Study in Japan

Tetsuya Tatsuta,Hiroki Sato,Yusuke Fujiyoshi,Hirofumi Abe,Akio Shiwaku,Junya Shiota,Chiaki Sato,Masaki Ominami,Yoshitaka Hata,Hisashi Fukuda,Ryo Ogawa,Jun Nakamura,Yuichiro Ikebuchi,Hiroshi Yokomichi 대한소화기 기능성질환∙운동학회 2022 Journal of Neurogastroenterology and Motility (JNM Vol.28 No.4

Background/Aims ManoScan and Sandhill high-resolution manometry (HRM) systems are used worldwide; however, the diagnosis of achalasia on the Starlet HRM system is not fully characterized. Furthermore, the impact of calcium channel blockers and nitrites in treating achalasia has not been investigated using HRM. Management of recurrent cases is a priority issue, although few studies have examined patient characteristics. Methods We conducted a multicenter, large-scale database analysis. First, the diagnosis of treatment-naive achalasia in each HRM system was investigated. Next, patient characteristics were compared between type I-III achalasia, and the impact of patient characteristics, including calcium channel blocker and nitrite use for integrated relaxation pressure (IRP) values, were analyzed. Finally, patient characteristics with recurrent achalasia were elucidated. Results The frequency of type I achalasia with Starlet was significantly higher than that with ManoScan and Sandhill HRM systems. In achalasia, multivariate analysis identified male sex, advanced age, long disease duration, obesity, type I achalasia, and sigmoid type as risk factors related to normal IRP values (< 26 mmHg). Calcium channel blockers and nitrites use had no significant impact on the IRP values, although achalasia symptoms were indicated to be alleviated. In recurrent cases, the IRP value was significantly lower, and advanced age, long disease duration, and sigmoid type were more common than in treatment-naive patients. Conclusions We should cautiously interpret the type of achalasia and IRP values in the Starlet HRM system. Symptoms of recurrent cases are related to disease progression rather than IRP values, which should be considered in decision making.

Improving the Surface Functionality of Curdlan by Conjugation with Unfolding Protein through Naturally Occurring Maillard Reaction

Soichiro Nakamura,Masahiro Ogawa,Hiroki Saeki,Masayoshi Saito,Satoko Miyasaka,Junya Hata,Naoko Adachi,Jae-Kwan Hwang 한국식품영양과학회 2000 Preventive Nutrition and Food Science Vol.5 No.4

Protein conjugation of curdlan belonging to β-1,3-glucan was carried out to improve its surface functionalities. The glucan was mixed with phosvitin, α_s-casein, lysozyme or ovalbumin, respectively. The mixture was freeze-dried, and the resulting powder was incubated at 60℃ and 79% relative humidity for 12 days in order to generate a controlled Maillard reaction between curdlan and proteins. Conjugation with unfolding proteins, i.e., phosvitin and α_s-casein, drastically increased the solubility of the glucan, whereas lysozyme and ovalbumin did not. The solubility in water of curdlan was 3.44% for the phosvitin conjugate and 1.09% for the α_s-casein conjugate. SDS-slab polyacrylamide gel electrophoresis showed that curdlan was solubilized due to covalent binding with phosvitin. Emulsifying properties of curdlan were substantially improved by the conjugation with phosvitin and α_s-casein. Emulsion stability of the curdlan-phosvitin conjugate was about 2.9 times greater than that of the curdlan-phosvitin mixture.