Structural changes in cell wall of Japanese radish accompanied by release of rhamnogalacturonan during pressure cooker heating

• Published in: Food chemistry 2021-07, Vol.349, p.129117-129117, Article 129117
• Main Authors: Tsuchida, Mitose, Yamaguchi, Hideyuki, Katayama, Norihisa, Sato, Yoko, Kawashima, Wakano, Kasai, Midori
• Format: Article
• Language: English
• Subjects: 13C CP/MAS NMR; 13C PST/MAS NMR; Alcohol insoluble solids; Cell Wall - chemistry; Cell wall polysaccharides; Cooking; Hot Temperature; Japanese radish; Magnetic Resonance Spectroscopy; Metalions; Mobility; Pectins - analysis; Pressure; Raphanus - chemistry; Rhamnogalacturonan; Rhamnogalacturonans - chemistry; Water - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.129117

•Cell wall of heated Japanese radish between 100 °C and 117 °C were compared.•Eluted components from AIS of raw samples heated in water were analyzed.•13C CP/MAS NMR couldn’t discriminate between temperatures of AIS from heated samples.•PST/MAS NMR showed clear signal changes in side chain of RG depending on temperature.•Heating radish at 117 °C for 3 h caused loosening of cell wall with keeping its shape. Changes in the cell wall of Japanese radish due to heating at 100 °C or 117 °C for 3 h were examined. Signals in 13C cross polarization magic angle spinning solid-state NMR (which detects rigid components) showed no differences between heating temperatures. 13C pulse saturation transfer magic angle spinning NMR (which detects flexible components) showed clear temperature-dependent changes in the rhamnose side chains of rhamnogalacturonan. Alcohol-insoluble solids isolated from raw samples were heated in water at 100 °C or 117 °C for 3 h. The concentrations of dissolved sugars and metal ions measured after heating in water at 117 °C were greater than in samples heated at 100 °C, indicating that loosening of cell wall structures increased with temperature, likely via degradation and elution of rhamnogalacturonan followed by β-elimination of homogalacturonan, and fewer interactions between cell wall components, including divalent metal ions. Vegetable shape was retained despite fewer interactions.