Evaluation of potentially harmful Maillard reaction products in different types of commercial formulae

Pasteurisation and spray drying are critical steps to ensure the safety and shelf-life of formulae, but these treatments also induce formation of some potentially harmful Maillard reaction products. In this study, the occurrence of potentially harmful Maillard reaction products and proximate compositions in different commercial formulae were analysed. Our results showed that infant formulae had significantly higher concentrations of furosine, Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) than follow-on/toddler formula. Specialty formulae had higher concentrations of glyoxal and CML than other types of formulae. Correlation analysis indicated that concentrations of 5-hydroxymethylfurfural, 3-deoxyglucosone, CML and CEL were closely related to fat contents. These results provided insight into concentrations of potentially harmful Maillard reaction products in different types of formulae and provide a theoretical basis for further optimisation of processing.

Quality characteristics of goat milk powder produced by freeze drying followed by UV-C radiation sterilization

Goat milk was directly freeze-dried into milk powder after freezing and then sterilized using UV-C radiation to produce low-dose, medium-dose and high-dose UV-C radiation sterilized freeze-dried goat milk powder (LGP, MGP and HGP). UV-C sterilization effectively reduced the total bacteria count and coliform bacteria in the goat milk powder while preserving the active proteins, and maintaining the color unchanged. Additionally, LGP, MGP, and HGP all exhibited a moisture content below 5 g/100 g and water activity below 0.5. Upon reconstitution, the milk powder formed uniform and stable emulsion. During accelerated storage tests, the increased Aw did not compromise the microbial quality of milk powder, and there were no significant changes in active proteins as confirmed via SDS-PAGE results. Furthermore, the color parameters (a*, b* and ΔE) showed a strong correlation with hydroxymethyl furfural levels.

Cowhide gelatin peptide as a source of antioxidants for inhibiting the deterioration of pudding quality during storage

To investigate the effect of gelatin peptide on the inhibition of quality deterioration in stored pudding, gelatin peptide with antioxidant properties was added to pudding products. For this purpose, a pudding recipe containing gelatin peptides was created. The gelatin peptides were characterized based on their antioxidant activity and protein structure. It was found that gelatin peptides had better antioxidant properties, lower thermal stability and crystallinity, higher hydrophobic amino acid content, and greater surface hydrogen bond exposure than commercially available peptides. Properties such as the pH, colony growth, and sensory characteristics of the pudding were characterized at 4 °C and 25 °C. The results showed that the addition of 0.5-1.0 % gelatin peptide to pudding was capable of significantly (P< 0.05) slowing down the decline in pH and sensory scores of the pudding and significantly inhibiting colony growth. It could prolong its storage life by five days at 4 °C and three days at 25 °C.

Goat milk powder supplemented with branched-chain fatty acid: influence on quality and microstructure

BACKGROUND

Branched-chain fatty acid (BCFA) is effective in preventing and helping to treat neonatal necrotizing enterocolitis. It is essential to supplement goat-milk powder for formula-fed preterm infants with BCFA. In this study, the quality and microstructures of milk powders supplemented with different concentrations of BCFA were evaluated, using goat milk powder without BCFA as the control group (CG).

RESULTS

In comparison with the CG, goat milk powder supplemented with BCFA exhibited smaller fat globules and a significant drop in overall particle size. During 16 weeks of storage, BCFA-supplemented groups showed suitable moisture content and viscosity and good solubility. The BCFA also helped reduce the number of folds on the surface of the milk powder particles.

CONCLUSION

The findings of this study indicate that goat milk powders with BCFA exhibit differences in quality and microstructure in comparison with ordinary goat milk powder, which is relevant for the future development and application of BCFA in foods. © 2022 Society of Chemical Industry.

Research advances of advanced glycation end products in milk and dairy products: Formation, determination, control strategy and immunometabolism via gut microbiota

Advanced glycosylation end products (AGEs) are a series of complex compounds which generate in the advanced phase of Maillard reaction, which can pose a non-negligible risk to human health. This article systematically encompasses AGEs in milk and dairy products under different processing conditions, influencing factors, inhibition mechanism and levels among the different categories of dairy products. In particular, it describes the effects of various sterilization techniques on the Maillard reaction. Different processing techniques have a significant effect on AGEs content. In addition, it clearly articulates the determination methods of AGEs and even discusses its immunometabolism via gut microbiota. It is observed that the metabolism of AGEs can affect the composition of the gut microbiota, which further has an impact on intestinal function and the gut-brain axis. This research also provides a suggestion for AGEs mitigation strategies, which are beneficial to optimize the dairy production, especially innovative processing technology application.

Quality indicators in lactose hydrolyzed milks and soy beverages from Colombia

Worldwide there is great interest in producing low lactose milk and drinks, such as soy beverages, suitable for consumption by lactose-intolerant people. These products have different carbohydrate compositions, which affect quality indicators derived from Maillard reaction (furosine and 5-hydroxyl-methyl furfural, HMF). In this study, quality parameters have been determined in 11 commercial samples (8 lactose-hydrolyzed milks and 3 soy beverages). Presence of β-galactooligosaccharides in milks (22.2-458.1 mg/100 mL) correlating roughly with the remaining lactose content (1.9-357.7 mg/100 mL). Soy beverages contained α-galactosides in concentrations of 30-75 mg/100 mL. HMF and furosine were detected in all milk samples. In addition, powdered milks subjected to controlled storage (40 °C, a_w 0.44) showed a furosine increase up to 88%. In conclusion, a great composition diversity was observed in the different products, probably favored by the lack of regulation and underline the importance of controlling processing and storage conditions to preserve product quality.

Profiles of initial, intermediate, and advanced stages of harmful Maillard reaction products in whole-milk powders pre-treated with different heat loads during 18 months of storage

This study evaluated the chemical changes in five types of whole-milk powders (WMP) with different heating loads during storage. The WMP was preheated using low-heat [low-temperature long-time (LTLT), high-temperature short-time pasteurization (HTST)] and high-heat process [ultra-pasteurization (ESL), ultra-high-temperature (UHT) treatments, and in-bottle sterilization (BS)]. Furosine increased by 2.5-3.0 times in high-heat WMP and 5.7-8.4 times in low-heat WMP during storage. 5-(hydroxymethyl)furfural (HMF) content in high-heat WMP was on average 1.4- to 2.4-fold higher than in low-heat WMP during storage. The increases in the amount of Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) in high-heat WMP were more than that in low-heat WMP (CML, 3.4-4.9 vs 3.1-3.4 times; CEL, 3.4-4.2 vs 2.7-3.0 times). Pyrraline in high-heat WMP increased by 1.8- to 2.1-fold. 2-Furaldehyde, CML, and CEL increased slowly with 12 months of storage and then accelerated. Storage time significantly contributed to more furosine, HMF, CML, and CEL contents in high-heat WMP.

Characteristics on the oxidation stability of infant formula powder with different ingredients during storage

Infant formula powder is prone to oxidation reaction during storage, which leads to the decrease of milk powder quality. The whole milk powder (WMP) was formulated, and the characteristics of infant formula powder were tracked during storage. The addition of metal ions, polyunsaturated fatty acids, and vitamins could reduce the peroxide value and increase the thiobarbituric acid value in the infant formula powder during the early stage of storage. When the samples were stored for 6 months, the free fat content of the base milk powder and the sample added with metal ions had high level (3.3%-3.6%). With adding vitamins, the content of free fat in the samples decreased first and then increased. The color value L of all the samples decreased during storage. Compared with WMP, the color value B of all the infant formula powder with different ingredients decreased. Levels of 2-heptanone and 2-nonaone indicated that the formation of the main methyl ketones in the infant formula powder with different ingredients decreased. The content of hexanal in the sample added metal ions was the highest. The type and intensity of free radicals changed with the formula components. The range of g value was 2.0043-2.0060 after 6 months of storage and 2.0017-2.1338 after 12 months of storage, respectively. The index of peroxide value and color value B were significantly related to the existence of free radicals in the infant formula powder with different ingredients.