Lima bean (Phaseolus lunatus Linn.) protein isolate as a promising plant protein mixed with xanthan gum for stabilizing oil-in-water emulsions.

BACKGROUND: Lima bean protein isolate (LPI) is an underutilized plant protein. Similar to other plant proteins, it may display poor emulsification properties. In order to improve its emulsifying properties, one effective approach is using protein and polysaccharide mixtures. This work investigated the structural and emulsifying properties of LPI as well as the development of an LPI/xanthan gum (XG)-stabilized oil-in-water emulsion. RESULTS: The highest protein solubility (84.14%) of LPI was observed and the molecular weights (Mw ) of most LPI subunits were less than 35 kDa. The enhanced emulsifying activity index (15.97 m2 g-1 ) of LPI might be associated with its relatively high protein solubility and more low-Mw subunits (Mw < 35 kDa). The effects of oil volume fraction (ϕ) on droplet size, microstructure, rheological behavior and stability of emulsions were investigated. As ϕ increased from 0.2 to 0.8, the emulsion was arranged from spherical and dispersed oil droplets to polyhedral packing of oil droplets adjacent to each other, while the LPI/XG mixtures changed from particles (in the uncrowded interfacial layer) to lamellae (in the crowded interfacial layer). When ϕ was 0.6, the emulsion was in a transitional state with the coexistence of particles and lamellar structures on the oil droplet surface. The LPI/XG-stabilized emulsions with ϕ values of 0.6-0.8 showed the highest stability during a 14-day storage period. CONCLUSION: This study developed a promising plant-based protein resource, LPI, and demonstrates potential application of LPI/XG as an emulsifying stabilizer in foods. © 2023 Society of Chemical Industry.

Transformation of ginsenosides by moderate heat-moisture treatment and their cytotoxicity toward HepG2 cells.

In the current study, the effects of heat-moisture treatment on the ginsenoside contents and ginsenoside compositions such as Rg3, CK and Rb1 etc. were investigated at different temperatures, relative humidities (RHs) and treatment times. Our findings demonstrated that the highest total ginsenoside content was 7.48% after 12 days treatment at temperature 80 °C and RH 75%. Correspondingly, less polar ginsenosides Rg3 and CK were accumulated increasingly from 0.88 mg/g and 0.84 mg/g to 7.30 mg/g and 15.08 mg/g, respectively, during heat-moisture treatment. Compared to the ginsenoside extracts of untreated ginseng (UGE), the ginsenoside extracts of heat-moisture treated ginseng (HMGE) exerted better scavenging activities of 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS+), and hydroxyl (OH) radicals, as well as higher cytotoxicity efficiency against HepG2. In addition, HMGE promoted cell apoptosis by up-regulating the related protein expression, especially the caspase-3, caspase-9, and poly (ADP-ribose) polymerase (PARP). Therefore, the cytotoxicity of HMGE against HepG2 cells may be due to the mitochondrial apoptosis pathway induced by up-regulated caspase. These results strongly proved the promising prospect of HMGE as functional food or ingredient in nourishing or disease chemoprevention.

Design and structural characterization of edible double network gels based on wheat bran arabinoxylan and pea protein isolate.

Double network (DN) gels based on wheat bran arabinoxylan (WBAX) and pea protein isolate (PPI) were fabricated by a two-step sequential gelation method with laccase catalyzed cross-linking followed by heating. The rheological properties, water holding capacity, microstructure and molecular structure of WBAX/PPI DN gels were investigated. Increasing the concentrations of WBAX and PPI contributed to an enhanced viscoelastic modulus of DN gel, which exhibited an interconnected, bicontinuous and compact structure with smaller pore sizes, as a result of higher cross-linking intensity of WBAX molecules. Low field nuclear magnetic resonance (LF-NMR) results showed that increasing the contents of PPI and WBAX could further restrict the water mobility within DN gel, which was beneficial for enhancing the water holding capacity of gel samples. The molecular structure analysis showed that the crosslinking of WBAX-WBAX, PPI-PPI and WBAX-PPI participated in the formation of WBAX-PPI DN gels.

Effect of water sorption on glass transition and microstructural variation of dextran & sugar mixtures.

Dextran is widely used as a model polysaccharide to study the interactions between polysaccharides and small molecule sugars. This study examined water sorption isotherms and glass transition temperatures (Tg) of mixtures of dextran with trehalose, lactose and sucrose for understanding how different disaccharides affect dextran's processing adaptation and storage performance relevant to water sorption. At the same chemical composition, monolayer water (m0) was dextran & sucrose (dex&suc) > dextran & trehalose (dex&tre) > dextran & lactose (dex&lac). The higher ratios of dextran, the higher was the Guggenheim constant (C) value of the mixtures. The compatibility of dextran and disaccharides was dex&tre > dex&lac > dex&suc. Gordon-Taylor model showed dex&tre (2:1) best inhibited water plasticization. Furthermore, trehalose and lactose were more effective in preventing morphological changes of hydrous matrices in the mixtures. The crystallinities of samples at 43% relative humidity (RH) were slightly lower than that at 11% RH.

Lactobacillus rhamnosus LRa05 Ameliorate Hyperglycemia through a Regulating Glucagon-Mediated Signaling Pathway and Gut Microbiota in Type 2 Diabetic Mice.

In this study, we aimed to explore the antidiabetic effects of Lactobacillus rhamnosus LRa05 on glucose metabolism and gut microbiota in type 2 diabetes mellitus (T2DM) mice. Our data indicated that the fasting blood glucose levels were reduced by 53.5% after treatment with LRa05 at a dose of 109 CFU·day-1. Meanwhile, LRa05 attenuated insulin resistance, relieved hepatic oxidative stress, and alleviated metabolic lipopolysaccharide-related inflammation in T2DM mice. LRa05 promoted the expression of glucose transporter 2, while it inhibited the expression of glucagon receptor, glucose-6-phosphatase, cellular adenosine-3'-5'-cyclic monophosphate-dependent protein kinase, and phosphoenolpyruvate carboxykinase in diabetic mice. Meanwhile, LRa05 reshaped gut microbiota, resulting in increased short-chain fatty acid bacteria (Alloprevotella and Bacteroides) and decreased proinflammatory bacteria (Odoribacter and Mucispirillum). Thus, LRa05 may be used as a functional food supplement for modulating the disorder glucose metabolism and gut microbiota in T2DM.