Exploring the mechanisms of charged polysaccharides in regulating the microstructure, texture, and rheology of camellia oleosomes-based meat analogs

Abstract

Plant-based meat analogs produced via the extrusion process still face challenges in replicating the textural attributes of real meat. This study aimed to investigate the effects of different charged polysaccharides, including anionic gellan gum (GG), neutral konjac glucomannan (KG), and cationic chitosan (CH), as well as their combinations (50:50 ratios) on the textural, rheological, and structural properties of camellia oleosomes-integrated meat analogs. Results showed that oleosomes mainly acted as active fillers within the interstitial spaces of textured proteins, transforming porous matrices into oleosome-embedded protein structures, which contributed to enhanced elastic properties. Furthermore, the incorporation of GG into the oleosome-protein matrices led to the formation of irregularly shaped pores and a sparse gel structure. In contrast, CH contributed to the development of a highly interconnected gel network, which not only immobilized water molecules but also enhanced the hardness from 7.01 N to 13.24 N and structure recovery ability from 65.78 % to 84.10 %. Furthermore, it was found that the sequential addition of CH/GG produced synergistic effects that enabled the meat analogs to develop a robust network with more connection zones and smaller pore sizes compared to CH/KG or GG/KG meat analogs. Lissajous-Bowditch data further revealed that GG/KG combination produced a more flexible gel structure that readily underwent erratic and abrupt deformations at ≤100 % strain amplitude. In contrast, CH/KG and CH/GG meat analogs demonstrated greater structural elasticity and resistance to large deformations (≤400 %), which was attributed to the slow relaxation behavior of their rigid, interconnected double-network structures composed of two interpenetrating polymer networks: a protein-polysaccharide network and a polysaccharide-polysaccharide network.