PDF(Pubmed)
Abstract：
Milk fat globules or milk fat globule membranes (MFGs/MFGM) have been added to the infant formula to fortify the phospholipids and narrow the nutritional gap from breast milk. The main aim of this study was to profile the interfacial and thermal properties of MFGs/MFGM prepared from ultrasonicated bovine milk. Bovine milk was sonicated at ultrasonic intensities of 20 kHz and 40 kHz independently or synchronously with the duration time of 0 min (control), 5 min, 10 min, and 15 min (work/rest cycles = 5 s: 3 s). Ultrasonic treatments at 20 kHz/ 5 min and 20 + 40 kHz/ 5 min improved the volume density (%) of smaller particles (1-10 µm) while significantly decreasing the surface hydrophobicity (H0) (p < 0.05). 40 kHz/5 min samples showed significantly higher ζ- potential than the other samples (p < 0.05), which might be because more negative charges were detected. In comparison with control samples, ultrasonic treatments decreased the interfacial tension (π) between the air and MFGs/MFGM liquid phase. 20 kHz ultra-sonicated treatments decreased the diffusion rate (k diff) of MFGs/MFGM interfacial compositions significantly as the duration prolonged from 5 min to 15 min (p < 0.05) but did not affect the adsorption or penetration rate (k a) (p > 0.05). X-ray diffraction (XRD) results showed that α-crystal peaks only existed in control and ultrasonicated 5 min samples but disappeared in all 15 min samples. According to the different scanning calorimetry (DSC), one or two new exothermic events (in the range of 17.29 - 18.81 ℃ and 22.14 - 25.21 ℃) appeared after ultrasonic treatments, which, however, were not found in control samples. Ultrasonic treatments resulted in the low-melting fractions (LMF) (TM1) peaks undetectable in MFGs/MFGM samples in which only peaks of medium-melting fractions (MMF) (TM2) and high-melting fractions (HMF) (TM3) were detected. Compared with the control, both enthalpies of crystallisation (ΔHC) and melting (ΔHM) decreased in ultrasonicated samples. In conclusion, ultrasonic treatment affects the interfacial and thermal properties of MFGs/MFGM.
摘要：
乳脂球或乳脂球膜（MFGs/MFGM）已添加到婴儿配方食品中，以强化磷脂并缩小母乳的营养差距。这项研究的主要目的是概述由超声处理的牛乳制备的MFGs/MFGM的界面和热性能。牛乳在20kHz和40kHz的超声强度下独立地或同步地超声处理,持续时间为0min(对照),5分钟,10分钟,和15分钟（工作/休息周期=5s：3s）。20kHz/5分钟和20+40kHz/5分钟的超声处理提高了较小颗粒（1-10μm）的体积密度（％），同时显着降低了表面疏水性（H0）（p<0.05）。40kHz/5min样品显示出明显高于其他样品的ζ-电位（p<0.05），这可能是因为检测到更多的负电荷。与对照样品相比，超声处理降低了空气与MFGs/MFGM液相之间的界面张力（π）。20kHz超声处理显著降低了MFGs/MFGM界面组合物的扩散速率(kdiff),随着持续时间从5min延长至15min(p<0.05),但不影响吸附或渗透率(ka)(p>0.05)。X射线衍射（XRD）结果表明，α-晶体峰仅存在于对照和超声处理5分钟的样品中，但在所有15分钟的样品中都消失了。根据不同的扫描量热法(DSC),超声处理后出现一个或两个新的放热事件（在17.29-18.81℃和22.14-25.21℃范围内），which,然而,在对照样品中没有发现。超声处理导致在MFGs/MFGM样品中检测不到的低熔点馏分（LMF）（TM1）峰，其中仅检测到中等熔点馏分（MMF）（TM2）和高熔点馏分（HMF）（TM3）峰。与对照相比，超声样品的结晶焓（ΔHC）和熔融焓（ΔHM）均降低。总之,超声处理影响MFGs/MFGM的界面和热性能。
