Infant formula (IF) is the second most significant global food after human milk. A comparative analysis of the composition and distribution of fatty acids (FAs) and triacylglycerols (TAGs) in human milk and IFs from Egypt was conducted with those from their Chinese counterparts. Eight brands of IF available in the Egyptian market exhibited significant differences in FA and TAG profiles compared to human milk. Specifically, all IFs had lower levels of saturated fatty acids (SAF) and higher levels of monounsaturated fatty acids (MUFAs) than human milk. Additionally, ultraperformance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry (UPSFC-Q-TOF-MS) analysis revealed the presence of more than 144 and 142 TAGs in human milk and IFs, respectively. The most prevalent TAG composition in human milk and IF were O/P/O and O/O/O, respectively. Based on individual similarity index (ISI) calculations, Chinese IFs outperformed Egyptian IFs in all TAGs containing palmitic acid.

Branched-chain fatty acids (BCFAs) consist of a wide variety of fatty acids with alkyl branching of methyl group. The most common BCFAs are the types with one methyl group (mmBCFA) on the penultimate carbon (iBCFA) or the antepenultimate carbon (aiBCFA). Long-chain mmBCFAs are widely existing in animal fats, milks and are mostly derived from bacteria in the diet or animal digestive system. Recent studies show that BCFAs benefit human intestinal health and immune homeostasis, but the connection between their content, distribution in the human and their nutritional functions are not well established. In this paper, we reviewed BCFAs from various dietary sources focused on their molecular species. The BCFAs biosynthesis in bacteria, Caenorhabditis elegans, mammals and their distribution in human tissues are summarized. This paper also discusses the nutritional properties of BCFAs including influences on intestinal health, immunoregulatory effects, anti-carcinoma, and anti-obesity activities, by highlighting the most recent research progress.

This study aims to prepare infant formula concentrates (IFs) simulating human milk fat globule (HMFG) composition, size and distribution. Mixed plant oil (21.3% palm oil, 2.8% flaxseed oil, 2.6% soybean oil, 29.9% rapeseed oil and 43.4% corn oil) and concentrated whey protein were applied to mimic triacylglycerols and phospholipids in HMFG respectively. IF1-IF6 were produced by different homogenization pressures or physically mixed with different proportions. IF4, prepared with 95% IF1 (4.29 μm), 1% IF2 (0.497 μm) and 4% IF3 (9.43 μm), showed a mean particle size of 3.96 μm and 49.77% milk fat globule membrane protein, and had the closest size distribution and interface with HMFG. The prepared IFs showed good stability with the Turbiscan stability index (IF6 (1.75) © 2023 Elsevier Ltd

Understanding human milk triacylglycerols (TAGs) provides valuable insights for infant formula development. This study utilized ultra-performance supercritical fluid chromatography to investigate how lactation stages and maternal diet affect TAG profiles. 18:1/16:0/18:1 (O/P/O), 16:0/18:1/16:0 (P/O/P), and 18:1/16:0/18:2 (O/P/ L) were most abundant in human milk, accounting for 20% of the total TAGs. Furthermore, significant differences in TAG compositions were observed across the three stages of lactation. Also, there are apparent differences in the TAG of Egyptian and Chinese human milk. Egyptian human milk exhibited higher levels of TAGs esterified with three saturated fatty acids (SSS), TAGs esterified with two saturated fatty acids, and one unsaturated fatty acid (S2U), and total palmitic acid compared to Chinese human milk. On the other hand, TAGs with three long-chain fatty acids (LLL) and TAGs with three unsaturated fatty acids (UUU) were at higher levels in Chinese human milk. Understanding the prevalence of these specific TAGs, particularly related to O/P/O, can help in formulating infant formulas that aim to mimic the composition of human milk more accurately.

分析我国6个城市3个哺乳期的母乳中脂肪酸的组成和含量，探究哺乳期和地理位置对母乳脂肪酸含量的影响。从包头（n=41）、北京（n=40）、济南（n=20）、昆明（n=33）、深圳（n=21）和西宁（n=49）6个城市共收集204例母乳，其中初乳28例，1月龄乳67例，4月龄乳109例。以C11:0为内标，采用气相色谱分析母乳中脂肪酸的含量，结果显示：成熟乳中脂肪含量显著高于初乳（P＜0.05），济南地区母乳中脂肪含量最高（～5 g/100 mL），昆明和深圳地区最低（＜3.0 g/100 mL）。哺乳期间C16:0的含量较稳定，为192 mg/g；初乳富含长链不饱和脂肪酸，初乳中C18:2 n-6c和C18:3 n-3的含量显著低于成熟乳（P＜0.05）。不同地区的母乳中脂肪酸含量有一定的差异，其中亚油酸/亚麻酸的比值差异很大。进一步比较了本文的数据与其他国家母乳脂肪酸含量的差异。本研究为母乳脂肪酸的定量分析及母乳脂肪酸浓度的影响因素提供理论参考。

Milk fat globules (MFGs) are all mammals' natural physical state of fat in milk emulsion. The distribution of bioactive lipids, especially fat-soluble vitamins, in MFGs is of great interest. In this manuscript, we present a confocal Raman microscopy (CRM) method for chemical mapping of different groups of lipids and β-carotene in MFGs of human, bovine, and goat milk. Using the developed method, the unsaturation ratio (I1658/I1443), C–C intensity ratio (I1063+I1125)/I1083, and C–H intensity ratio (I2885/I2850) of MFGs were quantified, showing significant differences as a function of species, i.e., human, bovine or goat, but not as a function of MFG size (8 μm). The Raman fluidity of dairy animal milk agrees with the molecular diffusion quantified by fluorescence recovery after photobleaching. The CRM maps indicate that β-carotene is ordered in a triacylglycerol core and surrounded by phospholipids. © 2023 Elsevier Ltd

Commercial milk is one of the most well-known substitutes for human milk. In view of this, we performed an in-depth examination of human milk compared with camel milk. Results showed that human milk and camel milk have the same levels of saturated fatty acids. Human milk contained a higher proportion of polyunsaturated fatty acids, while camel milk had a higher content of monounsaturated fatty acids. Using UPC2/Q-TOF-MS, 146 and 136 triacylglycerols were identified in human and camel milk, respectively. Compared with camel milk, human milk contains more triglycerides composed of polyunsaturated fatty acids. We identified five major types of phospholipids in human and camel milk, with camel milk showing higher total phospholipid content than human milk. In addition, camel milk contains more cholesterol and fat-soluble vitamins than human milk. This study can provide a theoretical basis for improving infant formulas. © 2023 Elsevier Ltd

This study aims to evaluate the in vitro gastrointestinal lipolysis and proteolysis of milk using a dynamic digestion simulation of infants and a static digestion simulation of adults following INFOGEST 2.0. Human breast milk and cow milk were used as substrates in our two models to evaluate their different digestion behaviors by deter-mining lipolysis and proteolysis production respectively as well as microstructural characteristics. The gastric lipolysis degree at 120 min was 18.72% under infant digestion, higher than that for the adult (10.76%). How-ever, no significant difference was found between human milk (73.69%) and cow milk (76.43%) in the end. The molecular species of lipolysis production were identified and quantified using LC-MS, which was highly related to their initial lipid compositions. Higher amounts of LCFA-containing lipolysis were detected at the beginning of human milk intestinal digestion under infant model. The proteolysis of human milk under infant digestion was slower than that of cow milk in the adult model, although the former has a nearly 2% lower protein content than the latter. In both models, whey proteins are more resistant to gastric digestion, while caseins are more exten-sively hydrolyzed. A larger mean fat globule size was observed in human milk during intestinal digestion, compared to the opposite phenomenon of cow milk. The established model is meaningful for evaluating the chemical composition and structure of digestion products for further development of novel infant formulas that are better for infant digestion and functional foods that are easily digested for people with intestine dysfunction.

Branched-chain fatty acids (BCFAs) and odd-chain fatty acids (OCFAs) in mammalian milk, dairy products, and vegetable oils were investigated; 72 fatty acids, including 16 BCFAs and 10 OCFAs, were identified and quantified using GC/TOF-MS. Human milk showed the lowest content of BCFA (0.4% of total FA) and the content in other milk ranged from 2 to 6%, of which ai17:0, i17:0, ai15:0 and i15:0 were most abundant. Differences in the content of OCFA in mammalian milk trended similarly to differences in BCFA content. The molecular species of BCFA in cow milk-derived dairy products were identical, but the content was different, with higher content in fermented dairy products. Apparent differences in BCFA and OCFA composition were found in infant formulas, strongly related to their fat sources. Vegetable oils contained no BCFA and a small amount of OCFA. A scientific basis for further investigation of high-BCFA and OCFA dairy products is provided. © 2023 Elsevier Ltd