Study on the impact of temperature, salts, sugars and pH on dilute solution properties of Lepidium perfoliatum seed gum

Abstract

The functional properties of food gums are remarkably affected by the quality of solvent/cosolutes and temperature in a food system. In this work, for the first time, the chemical characterizations and dilute solution properties of Lepidium perfoliatum seed gum (LPSG), as an emerging carbohydrate polymer, were investigated. It was found that xylose (14.27%), galacturonic acid (10.70%), arabinose (9.07%) and galactose (8.80%) were the main monosaccharaide components in the LPSG samples. The uronic acid content of LPSG samples was obtained to be 14.83%. The average molecular weight and polydispersity index of LPSG were to be 2.34 × 105 g/mol and 3.3, respectively. As the temperature was increased and the pH was decreased and the concentration of cosolutes (Na+, Ca2+, sucrose and lactose) presented in the LPSG solutions was enhanced, the intrinsic viscosity [η] and coil dimension (Rcoil, Vcoil, υs) of LPSG molecular chains decreased. Activation energy and chain flexibility of LPSG were estimated to be 0.46 × 107 J/kg.mol and 553.08 K, respectively. The relative stiffness parameter (B) of LPSG in the presence of Ca2+ (0.079) was more than that of Na+ (0.032). Incorporation of LPSG into deionized water (0.2%, w/v) diminished the surface activity from 76.75 mN/m to 75.70 mN/m. Zeta potential (ζ) values (−46.85 mV–−19.63 mV) demonstrated that dilute solutions of LPSG had strong anionic nature in the pH range of 3–11. The molecular conformation of LPSG was random coil in all the selected solution conditions. It can be concluded that temperature and presence of cosolutes can significantly influence on the LPSG properties in the dilute systems.

Salt and Temperature Effects on Xanthan Gum Polysaccharide in Aqueous Solutions

“…We found that our value was 28 and 12% smaller compared to [ η ] values for XG reported by Khouryieh et al [ 14 ] and Bak et al [ 11 ], respectively. Compared to other polysaccharides in water, our [ η ] was in several cases much larger, such as with two data points from Potier et al for alginate and carboxymethyl cellulose, 600% and 300%, respectively [ 19 ], 400% for basil seed gum [ 20 ], 200% with guar gum [ 14 ], and 400% for lepidium perfoliatum seed gum [ 21 ]. In comparison to the [ η ] for K-carrageenan [ 22 ], the [ η ] for XG is quite similar, with less than 10% deviation.…”

“…The general observation is that, as the ionic strength increases, XG structures tend to become more compact in configuration, as evidenced by the reduction of V E . The reduction in molecular dimension is a result of the charge screen effect on the electrostatic repulsions of the tri-saccharide side chains, leading to a more compact conformation [ 21 ]. This causes a decrease in the hydrodynamic coil radius of XG in solution.…”

Rheological properties of binary mixtures of Lepidium perfoliatum seed gum and xanthan gum

“…The seeds were then manually cleaned to remove all the impurities which visually could be identified. The Lepidium perfoliatum seed gum (LPSG) with average molecular weight of 2.34⨯10 5 Da was obtained according to the method described by Yousefi and Ako [2]. Xanthan gum with average molecular weight of 2 × 10 6 Da was purchased from Kelco (a division of Merck Co., New Jersey, USA).…”

“…It has been reported that xylose (14.27%), galacturonic acid (10.70%), arabinose (9.07%) and galactose (8.80%) are the main monosaccharaide components of LPSG. LPSG has 14.83% uronic acid and the average molecular weight of this biopolymer is 2.34 × 10 5 g/mol [5]. A shear-thinning behaviour of LPSG dispersions has been identified at various temperatures (5-65 °C) and concentrations (0.5-2%, w/w) [6].…”

Brassicaceae Familyasına ait Üç Lepidium Türünün Karşılaştırmalı Fitokimyasal İçerikleri ve Antioksidan Kapasiteleri

“…L. perfoliatum dünya genelinde yayılış göstermekte ve ekimi yapılmaktadır. Bu bitkinin tohumları, farmasötik etkileri nedeniyle geleneksel tıp reçetelerinde uzun süredir kullanılmaktadır (Yousefi et al 2022). L. cartilagineum, halofit bir tür olarak kabul edilmektedir (Schmotzer 2021).…”