Abstract：
The effects of carboxylation degree (0.3-2.4 mmol/g) of cellulose nanofiber (CNF) on the microstructure and mechanical properties of edible walnut oleogels were comprehensively examined. The oleogels were well prepared by emulsion-templated approach for potential substitute of conventional saturated or trans-fats in food products. The results demonstrated that the oil-binding capacity (OBC) and textural strength of oleogels enhanced with the increase of CNF carboxyl content, while the structural strength (G\' in rheological measurement) and the resistance to shear thinning was first decreased and then increased. It possibly reflected the competition on the dominant structuring mechanism by hydrogen bonding from cellulose hydroxyl groups and electrostatic interactions from -COONa function. With the combined mechanism, oleogel with low structural strength and relatively high OBC (CNF carboxyl content of 1.2 mmol/g, OBC >83 %, G\' ≈ 7 × 104 Pa and firmness of 0.30 N) and oleogel with enough structural rigidity and high OBC (CNF carboxyl content of 1.8 mmol/g, OBC >89 %, G\' of up to 1.7 × 105 Pa, and firmness of up to 0.66 N) were both fabricated. This reveals the feasibility of regulating oleogel structure and textual properties by using CNF as the unique oleogelator and simply changing its surface carboxyl function.
摘要：
研究了纤维素纳米纤维(CNF)羧化度(0.3~2.4mmol/g)对核桃凝胶微观结构和力学性能的影响。通过乳液模板法很好地制备了油凝胶，可替代食品中的常规饱和脂肪或反式脂肪。结果表明，随着CNF羧基含量的增加，油凝胶的油结合能力（OBC）和结构强度增强。而结构强度（流变测量中的G'）和剪切稀化阻力先降低后升高。它可能反映了纤维素羟基的氢键和-COONa功能的静电相互作用对主要结构机制的竞争。有了联合机制，具有低结构强度和相对较高的OBC的油凝胶（CNF羧基含量为1.2mmol/g，OBC>83%，G\'≈7×104Pa，硬度为0.30N）和具有足够结构刚度和高OBC的油凝胶（CNF羧基含量为1.8mmol/g，OBC>89%，G\'为1.7×105Pa，和高达0.66N)的硬度都是制造的。这揭示了通过使用CNF作为独特的油凝胶剂并简单地改变其表面羧基官能团来调节油凝胶结构和文本性质的可行性。
