再制干酪拉伸性的调控机制

Regulation Mechanism of Processed Cheese Stretchability

通过调控再制干酪体系乳化盐添加量(0.6%~3.0%)、pH值(5.4~5.8)和马铃薯醋酸酯淀粉添加量(0.125%~2%),研究再制干酪拉伸性的调控机制。结果显示,当乳化盐从0.6%增加至3.0%时,再制干酪中的结合钙含量从(4.42±0.05)g/kg降低至(0.02±0.04)g/kg,脂肪球粒径D_((4,3))从(73.08±3.16)μm降低至(27.90±2.55)μm,结合水相对含量从(9.57±0.25)%增加至(10.40±0.25)%,表明钙交联作用逐渐减弱,干酪的乳化效果增加,水合程度增加,蛋白分子间相互作用由强变弱,再制干酪的拉伸性因此先升高后降低;当pH值从5.4增加至5.8时,再制干酪中的结合钙含量从(2.01±0.08)g/kg增加至(2.74±0.05)g/kg,脂肪球粒径D_((4,3))从(36.36±2.68)μm降低至(21.37±2.39)μm,傅里叶变换红外光谱显示O—H和N—H的弯曲振动吸收峰均向低波数移动,结合水含量从(9.85±0.16)%增加至(10.74±0.12)%,表明钙交联作用、乳化效果和水合程度增加,蛋白分子间相互作用由强变弱,再制干酪的拉伸性因此先升高后降低;当马铃薯醋酸酯淀粉从0.125%增加至2%时,脂肪球粒径D_((4,3))从(54.17±2.74)μm降低至(29.92±2.71)μm,结合水相对含量从(9.90±0.38)%增加至(11.00±0.21)%,表明干酪的乳化效果和水合程度增加,拉伸性先升高后降低,其中当马铃薯醋酸酯淀粉添加量达到2%时,淀粉与蛋白质出现相分离,拉伸性变差。综上,再制干酪的拉伸性受钙离子螯合程度、乳化效果、蛋白质分子间静电相互作用、水分分布以及蛋白质-多糖相行为等多方面的综合调控。

In this work,the regulation mechanism of processed cheese stretchability was studied by adjusting the amount of added emulsifying salt(0.6%–3.0%)and potato acetate starch(0.125%–2%)and pH(5.4–5.8).The results showed that as the emulsifying salt increased from 0.6%to 3.0%,the content of bound calcium in processed cheese decreased from(4.42±0.05)to(0.02±0.04)g/kg,the average fat globule size D(4,3)decreased from(73.08±3.16)to(27.90±2.55)μm,and the bound water content increased from(9.57±0.25)%to(10.40±0.25)%,indicating that the calcium crosslinking effect gradually decreased,the emulsifying effect and hydration degree increased,the interaction between protein molecules changed from strong to weak,so the stretchability of processed cheese initially increased and then decreased.As pH increased from 5.4 to 5.8,the content of bound calcium increased from(2.01±0.08)to(2.74±0.05)g/kg,and the average fat globule size D(4,3)decreased from(36.36±2.68)to(21.37±2.39)μm.Fourier transform infrared spectroscopy showed that the bending vibration absorption peaks of O-H and N-H moved to lower wavenumbers, and the bound water content increased from (9.85 ± 0.16)% to (10.74 ± 0.12)%, indicating that the calcium crosslinking effect, emulsifying effect and hydration degree increased, the interaction between protein molecules changed from strong to weak, so the stretchability of processed cheese increased first and then decreased. As potato acetate starch concentration increased from 0.125% to 2%, the average fat globule size D(4,3) decreased from (54.17 ± 2.74) to (29.92 ± 2.71) μm, and the bound water content increased from (9.90 ± 0.38)% to (11.00 ± 0.21)%, indicating that the emulsifying effect and hydration degree increased, and the stretchability increased first and then decreased. At a potato acetate starch concentration of 2%, starch and protein were separated, so the stretchability became worse. In conclusion, the stretchability of processed cheese is comprehensively regulated by the degree of calcium ion chelation, emulsifying effect, electrostatic interaction between protein molecules, water distribution state and protein-polysaccharide phase behavior.