Harahap Iskandar Azmy, Sobral Maria Madalena C, Casal Susana, Pinho Susana C M, Faria Miguel A, Suliburska Joanna, Ferreira Isabel M P L V O
Department of Human Nutrition and Dietetics, Faculty of Food Science and Nutrition, Poznan University of Life Sciences, Poznan, Poland.
LAQV/REQUIMTE, Departamento de Ciências Químicas, Laboratório de Bromatologia e Hidrologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
Front Nutr. 2022 Jun 30;9:901006. doi: 10.3389/fnut.2022.901006. eCollection 2022.
Meat and fish are introduced into the diet as a source of protein, but these muscle foods present different fatty acid (FA) compositions and different lipid stabilities. Fatty fish is expected to oxidize due to its higher content of polyunsaturated FA (PUFA), whereas the higher heme-Fe content of red meat will also affect lipid stability. Combining other food ingredients within a meal also influences lipid oxidation, which will not stop after meals intake. This is due to the acidic environment of the stomach together with the presence of metallic ions, a process that is scarcely understood. The goal of this study was to evaluate the oxidation of fatty fish vs. meat meal diets under standardized semi-dynamic gastric conditions and FA release from the stomach to the duodenum. Meal diets composed by 25% beef meal (BM) or fatty fish meal (FM), 25% fried potatoes, and 50% sugar soft drink were prepared. Proximate composition, FA and amino acid profiles, and meals quality indices were evaluated. Their differences in composition led to different total gastric digestion time of 242.74 (BM) and 175.20 (FM) minutes. Using the INFOGEST semi-dynamic gastric model, 4 gastric emptying (GE) were simulated in both meals. In each GE, FA profile and lipid oxidation products (LOPs) formation were assessed. As a result, more than 50% FA release to the duodenum occurred in GE1, whose percentage decreased with the time of digestion. FM exhibited the highest LOPs formation, which corroborates the high peroxidizability index measured for this meal diet. Higher LOPs formation occurred in the later GEs, which released less FA. This suggests that higher times of residence in the stomach increase FA oxidation. This study shows a higher formation of LOPs during digestion of FM using a whole meal approach. These results relate to its richness in PUFAs compared to BM. Despite higher LOPs formation, FM digests that reached duodenum still contain higher content of unoxidized PUFAs compared with BM and a desirable ω3/ω6 PUFAs ratio of ~0.43. LOPs formation in PUFA-rich meals could be reduced if those meals have a low caloric value, avoiding large times of residence in the stomach and consequently high levels of oxidation.
肉类和鱼类作为蛋白质来源被纳入饮食，但这些肌肉类食物具有不同的脂肪酸（FA）组成和不同的脂质稳定性。富含脂肪的鱼类由于其较高的多不饱和脂肪酸（PUFA）含量而易于氧化，而红肉中较高的血红素铁含量也会影响脂质稳定性。在一餐中搭配其他食物成分也会影响脂质氧化，而且进食后脂质氧化不会停止。这是由于胃部的酸性环境以及金属离子的存在，而这一过程几乎不为人所了解。本研究的目的是在标准化的半动态胃部条件下评估富含脂肪的鱼类与肉类膳食的氧化情况以及脂肪酸从胃部到十二指肠的释放情况。制备了由25%牛肉粉（BM）或富含脂肪的鱼粉（FM）、25%炸土豆和50%含糖软饮料组成的膳食。评估了其近似成分、脂肪酸和氨基酸谱以及膳食质量指标。它们在成分上的差异导致了不同的总胃消化时间，牛肉粉膳食为242.74分钟，鱼粉膳食为175.20分钟。使用INFOGEST半动态胃部模型，对两种膳食模拟了4次胃排空（GE）。在每次胃排空过程中，评估脂肪酸谱和脂质氧化产物（LOP）的形成情况。结果，超过50%的脂肪酸在胃排空1时释放到十二指肠，其百分比随消化时间而降低。鱼粉膳食表现出最高的脂质氧化产物形成，这证实了该膳食测得的高过氧化性指数。在随后的胃排空过程中脂质氧化产物形成较多，而释放的脂肪酸较少。这表明在胃中停留时间越长，脂肪酸氧化程度越高。本研究表明，采用全膳食方法时，鱼粉膳食在消化过程中脂质氧化产物形成较多。这些结果与其相比牛肉粉富含多不饱和脂肪酸有关。尽管脂质氧化产物形成较多，但到达十二指肠的鱼粉消化物与牛肉粉相比仍含有较高含量的未氧化多不饱和脂肪酸，且ω3/ω6多不饱和脂肪酸比例约为0.43，较为理想。如果富含多不饱和脂肪酸的膳食热量值较低，避免在胃中停留时间过长从而避免高水平氧化，那么其中脂质氧化产物的形成可能会减少。
