背景:乳制品的热处理,包括巴氏杀菌和超高温(UHT)处理,改变牛奶的大分子结构,并最终影响消化。体外,动物,和人体研究表明,与巴氏杀菌牛奶(PAST-M)相比,食用UHT牛奶(UHT-M)后营养释放或循环出现更快,提出了更快的胃排空(GE)速率作为可能的机制。
目的:研究牛奶热处理对GE的影响,这是血液中营养物质出现更快的机制。我们假设UHT-M在食用后的GE和循环营养素递送比PAST-M更快。
方法:在这项双盲随机对照交叉试验中,健康女性(n=20;27.3±1.4岁,平均值±SD)习惯性乳制品消费者,消耗500mL的均质牛UHT-M或PAST-M(1340对1320kJ)。胃内容物体积(GCV)排空半衰期(T50)通过磁共振成像评估超过3小时主观消化症状,血浆氨基酸,脂质和B族维生素浓度,在5小时内测量胃肌电活动。
结果:尽管GCVT50没有差异(102±7分钟与89±8分钟,平均值±SEM,UHT-M和PAST-M,分别为;p=0.051),UHT-M与PAST-M相比,GCVT25延长了31%(42±2对32±4分钟,p=0.004)。而在UHT-M后,GCV在较长时间内保持较大(治疗×时间相互作用,p=0.002),UHT-M后血浆必需氨基酸AUC高于PAST-M(55324±3809对36598±5673μmol·min·L-1,p=0.006)。热处理不影响胃肌电活动,血浆食欲激素标志物或主观食欲评分。
结论:与预期相反,UHT-M的胃排空较慢,然而,正如预期的那样,氨基酸血症更大。UHT-M后较大的GCV表明,胃体积可能很难预测复杂食物基质的循环营养素外观。乳品热处理可能是通过影响消化动力学来改变营养释放的有效工具。
背景:www.anzctr.org.au(ACTRN12620000172909)。
BACKGROUND: Heat treatments of dairy, including
pasteurization and ultra-high temperature (UHT) processing, alter milk macromolecular structures, and ultimately affect digestion. In vitro, animal, and human studies show faster nutrient release or circulating appearance after consuming UHT milk (UHT-M) compared with pasteurized milk (PAST-M), with a faster gastric emptying (GE) rate proposed as a possible mechanism.
OBJECTIVE: To investigate the impact of milk heat treatment on GE as a mechanism of faster nutrient appearance in blood. We hypothesized that GE and circulating nutrient delivery following consumption would be faster for UHT-M than PAST-M.
METHODS: In this double-blind randomized controlled cross-over
trial, healthy female (n = 20; 27.3 ± 1.4 y, mean ± SD) habitual dairy consumers, consumed 500 mL of either homogenized bovine UHT-M or PAST-M (1340 compared with 1320 kJ). Gastric content volume (GCV) emptying half-time (T50) was assessed over 3 h by magnetic resonance imaging subjective digestive symptoms, plasma amino acid, lipid and B vitamin concentrations, and gastric myoelectrical activity were measured over 5 h.
RESULTS: Although GCV T50 did not differ (102 ± 7 min compared with 89 ± 8 min, mean ± SEM, UHT-M and PAST-M, respectively; P = 0.051), GCV time to emptying 25% of the volume was 31% longer following UHT-M compared with PAST-M (42 ± 2 compared with 32 ± 4 min, P = 0.004). Although GCV remained larger for a longer duration following UHT-M (treatment × time interaction, P = 0.002), plasma essential amino acid AUC was greater following UHT-M than PAST-M (55,324 ± 3809 compared with 36,598 ± 5673 μmol·min·L-1, P = 0.006). Heat treatment did not impact gastric myoelectrical activity, plasma appetite hormone markers or subjective appetite scores.
CONCLUSIONS: Contrary to expectations, GE was slower with UHT-M, yet, as anticipated, aminoacidemia was greater. The larger GCV following UHT-M suggests that gastric volume may poorly predict circulating nutrient appearance from complex food matrices. Dairy heat treatment may be an effective tool to modify nutrient release by impacting digestion kinetics.
BACKGROUND: www.anzctr.org.au (ACTRN12620000172909).