单棕榈酸山梨糖醇酯对塑型脂肪热性质及机械性能的影响

Effect of Sorbitan Monopalmitate Addition on Thermal and Mechanical Properties of Plastic Fats

本研究以棕榈硬脂为基料油,添加1.0%、2.0%、4.0%(质量比)的单棕榈酸山梨糖醇酯(SMP),考察不同浓度SMP的加入对混合油脂固体脂肪含量和热力学性质的影响,并模拟起酥油工业制备过程,考察不同SMP添加量对模型起酥油的质构及流变特性的影响,为工业生产中提高产品品质提供指导。结果表明:SMP的加入起到了稳定混合油脂晶体结构的作用,随着温度升高及SMP浓度的增加,稳定晶体结构的作用越显著,当温度达到33.3℃时,加入4%SMP的混合油脂比棕榈硬脂的固体脂肪含量提高了1.65%。在降温过程中,SMP的加入缩短了混合油脂的结晶诱导时间,1%、2%、4%SMP的加入均可使棕榈硬脂的结晶起始温度提高约5℃。加入2%、4%SMP的模型起酥油样品的质构特性及流变特性变化基本一致,加入2%SMP的模型起酥油硬度和弹性模量比未加入SMP的模型起酥油分别提高了30%和15%。从产品品质及生产成本考虑,加入2%SMP即缩短结晶诱导时间,又有效提高了产品性能。

The effects of sorbitan monopalmitate(SMP, 1.0%, 2.0%, 4.0%) on solid fat content and thermal crystallization behavior of palm stearin(PS) were investigated. A PS-based shortening was prepared under the simulating industrial process parameters. The effects of SMP on texture and rheological properties of the shortening samples were studied. The results showed that SMP played a role in stabilizing the crystal structure of the mixture of PS and SMP. With the increase of temperature and concentration of SMP, the stabilization of crystal structure became more significant. At the temperature of 33.3 ℃, the solid fat content of PS and 4% SMP was 1.65% higher than that of PS. In the cooling process,the addition of SMP shortened the induction time of crystallization of PS and SMP. The addition of 1%, 2% and 4% SMP could increase the onset crystallization temperature of PS and SMP by about 5 ℃. The texture and rheological properties of the shortening samples with 2% and 4% SMP were basically the same. The hardness and modulus of elasticity of the shortening samples with 2% SMP were 30% and 15% higher than those without SMP respectively. Considering the product quality and production cost, adding 2% SMP can shorten the crystallization induction time and effectively improve the product performance.