著者

Md. Fuad Mondal Md. Asaduzzaman Makoto Ueno Mikiko Kawaguchi Shozo Yano Takuya Ban Hideyuki Tanaka Toshiki Asao

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.MI-113, (Released:2016-04-23)

被引用文献数

19

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The consumption of vegetables and fruits rich in potassium (K), such as melons and strawberries, is restricted in chronic kidney disease (CKD) patients. Therefore, we attempted to produce low-K strawberry fruits through management of a KNO3 fertilizer in nutrient solution from anthesis to the harvest period. A general trend of decreasing K content in fruit was observed with the decrease of KNO3 concentration in the nutrient solution. Among four strawberry cultivars, the fruit of the ‘Toyonoka’ exhibited a K reduction of about 64% when plants were grown in nutrient solution with KNO3 at 1/16 of the normal level. Citric acid and ascorbic acid contents of ‘Toyonoka’ fruit were reduced with decreasing KNO3 concentrations in the nutrient solution. Although the reduced NO3− of the nutrient solution was adjusted by using Ca(NO3)2 to obtain low-K strawberries, growth, yield and quality did not vary with this adjustment. Compared with the typical level of K in strawberry fruit of 170 mg/100 g FW (Standard Tables of Food Composition in Japan, 2011), a 23.5% decrease (130 mg/100 g FW) in K was found in 1/32 level of KNO3. The K contents of plant parts suggested that the low KNO3 level was responsible for the low K absorption, which may have affected the translocation and accumulation of K into fruit. Therefore, 1/32 level of KNO3 in nutrient solution lowers the fruit K content considerably.

著者

Yoshihiro OSAWA Takafumi MIZUSHIGE Sayuri JINNO Fumihito SUGIHARA Naoki INOUE Hideyuki TANAKA Yukihito KABUYAMA

出版者

Biomedical Research Press

雑誌

Biomedical Research (ISSN:03886107)

巻号頁・発行日

vol.39, no.1, pp.1-11, 2018-02-01 (Released:2018-02-22)

参考文献数

35

被引用文献数

17 26

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A number of studies have shown that oral administration of collagen hydrolysate (CH) results in the absorption of di- and tri-peptides. In order to understand the dynamics of CH absorption and metabolism, molecular profiles of hydroxyproline (Hyp) and Hyp-containing peptides (HCPs) were analyzed by in situ perfusion of rat intestine and liver. The total amount of absorbed HCPs during 1 h of perfusion was 16.6 μmol, which was significantly higher than that of free Hyp (6.6 μmol). In addition, HCPs were also reliably detected in hepatic perfusate at the level higher than free Hyp. Thus, the results demonstrated that CH is absorbed predominantly as peptides, which subsequently enter systemic circulation. Size exclusion chromatography showed that perfusates include significant amount of HCPs larger than tripeptides, leading us to analyze these peptides in detail. Mass spectrometric analysis of intestinal perfusate finally identified three CH-derived peptides, which are surprisingly large as food-derived circulating peptides. Peptide quantitation by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that di- and tri-peptides, which are previously identified as major peptides in circulating blood, comprise only a part of HCPs in intestinal and liver perfusate. Finally, analysis of portal vein blood revealed that the larger peptides, such as pentadecapeptide identified in this study, could be absorbed in vivo. Taken all together, this study showed that peptides which are larger than tripeptide could reach to the circulation system after administration of CH, revealing previously unknown dynamics of absorption of CH.