The enzymatic hydrolysate of Zhongdian yak milk casein was fractionated by ultrafiltration into two fractions: molecular mass > 3 kDa and < 3 kDa. The cell proliferation activity and antioxidant activity of the two fractions were determined. The bioactive peptides derived from yak milk casein were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), bioinformatics and molecular docking. The results showed that the proliferation rate of RAW264.7 cells was above 80% in the presence of either the molecular mass > 3 kDa or < 3 kDa fraction. Both fractions had the ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) cation radical. The cell proliferation and free radical scavenging activity of the molecular mass < 3 kDa fraction were better than those of the > 3 kDa fraction. A total of 895 peptides were identified from the molecular mass < 3 kDa fraction, of which 96 were known bioactive peptides, mainly antioxidant peptides (39.6%) and angiotensin-converting enzyme inhibitory peptides (30.2%), indicating that Zhongdian yak casein is an important source of bioactive peptides. Based on their activity and hydrophobicity, antioxidant peptides GYF and RPW were selected from the predicted 20 potential antioxidant peptides. The results of molecular docking showed that the binding energies of GYF and RPW with ABTS cation and DPPH radicals were all negative, indicating that they had binding potential and exerted antioxidant activity mainly by forming hydrogen bonds and hydrophobic interactions.

According to the relevant requirements and methods specified in the Guidelines for Stability Study of Powdered Milk Formulae for Infants and Young Children (on Trial), nutrient decay in infant formula milk powder was investigated in accelerated and long-term tests. The results showed that the macronutrients and fatty acids in infant formula milk powder were relatively stable in both tests, with a decay rate of less than 5%. Vitamins did not significantly decay with a decay rate of less than 10%. The mineral iodine decayed evidently in the accelerated test, with a maximum decay rate of 11.37%. Other minerals did not significantly lose. The optional components were relatively stable in the accelerated and long-term tests, with a decay rate of less than 5%.

The production and storage process are closely related to the quality of infant formula milk powder. This study examined nutrient mixing homogeneity, the decay rate of nutrients and the changes in safety indicators during accelerated storage of infant formula milk powder. The results showed that among the 15 nutrients selected, the mixing uniformity of lactoferrin was above 90%, while the mixing uniformity of the other nutrients was above 95%. Under the accelerated storage conditions, macronutrients and fatty acids were relatively stable, and vitamins and minerals did not show significant attenuation. The decay rate of taurine as an optional ingredient was relatively high, being 8.06%, 8.40%, and 8.08% at the end of the accelerated storage for milk formulae for younger and older infants and young children, respectively. After accelerated storage for 186 days, the safety indicators (Tin, nitrate, nitrite, aflatoxin M1, and melamine) remained basically unchanged.

In recent years, consumer complaints about dairy products have been frequent, and dairy quality problems have become the focus of social and livelihood concerns. It is urgent to build a whole-chain quality traceability system for dairy production and improve the traceability system of dairy products. This paper deeply analyzes the whole quality information flow of dairy production, and reviews the traceability technologies currently used in dairy production. This review is expected to provide innovative control strategies for improving the dairy management system and help diary producers in reducing consumer complaints about quality problems.

The wet process for producing infant formula milk powder requires multiple heating processes, which can cause some nutrient loss. Mixing uniformity is an important indicator for measuring the effectiveness of the mixing process, which is used to measure whether various nutrient indicators are evenly dispersed in infant formula milk powder. When designing infant formula milk powder, the loss rate and mixing uniformity of nutrients should be taken into account to ensure that the quality of products meets the requirements of the national food safety standards. This study analyzed nutrient loss rate and mixing uniformity in the wet processing of infant formula milk powder. The results showed that the nutrient that was most lost in the wet process was vitamins. Vitamin A (VA), vitamin B1 (VB1), vitamin B12 (VB12), and vitamin C (VC) were lost by 19.2%, 20.4%, 33.9%, and 20.3%, respectively, while the other vitamins were not significantly lost. Minerals were relatively stable in the wet process, and no significant loss of inositol, taurine or galactooligosaccharides was observed; the mixing uniformity of VB1 was less than 95%, while the mixing uniformity of the other nutrients was above 95%.

Our aim was to understand the pollution levels and sources of chlorate and perchlorate in infant formula milk powder and to evaluate the risk of dietary exposure to chlorate and perchlorate in infants and young children. A total of 165 batches of samples were collected from the water, cow milk, and ingredients used, as well as 131 batches of infant formula milk powder. Chlorate and perchlorate in each sample were detected using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the data obtained were statistically analyzed. The results showed that chlorate and perchlorate were undetectable in the water samples. Cow milk was more severely polluted by perchlorate than by chlorate. Some ingredients were also found to contain chlorate and perchlorate. Infant formula milk powder was contaminated with chlorate and perchlorate, with average contents of 34.3 and 14.5 μg/kg, respectively. The average dietary exposure levels to chlorate and perchlorate for infants aged 0–6 months were 0.71 and 0.28 μg/(kg·d), respectively, which were at an acceptable level. Infant formula milk powder and the raw materials used were found to be contaminated by chlorate and perchlorate.

The composition and content of amino acids in infant formula sold in China were investigated in comparison with human milk at different lactation stages. An amino acid analyzer was used to detect the contents of free and hydrolyzed amino acids in commercial infant formula, and total amino acid content and the proportion of individual amino acids were calculated. The results showed that free amino acids were detected in some of the 12 samples, while hydrolyzed amino acids were detected in all these samples. The average concentration of most amino acids was close to that of human milk at 1 to 60 d of lactation, and higher than that of human milk at 61 to 180 d. The average ratio of essential to total amino acids was 46.43%, which was close to that of human milk. The proportions of methionine and tryptophan to total amino acids were higher than those of human milk, the proportions of arginine and cystine to total amino acids were lower than those of human milk, and the proportion of other amino acids to total amino acids was close to that of human milk. This study reveals the difference in amino acid content between commercial infant formula and human milk.

Milk allergy is a severe foodborne illness. This disease usually occurs due to the interaction between milk proteins and their metabolites, leading to immune dysfunctions in the body. Milk allergy is gradually becoming a major global public health problem, especially for infants and young children. This review elaborates the mechanism behind the allergenicity of bovine casein, α-lactalbumin and β-lactoglobulin, introduces the technologies that have currently been successfully used in the detection of bovine milk allergens, discusses their advantages and disadvantages in practical applications, and systematically summarizes the physical, chemical and biological modification methods to reduce the allergenicity of bovine milk proteins. Finally, some hypoallergenic dairy products developed by researchers in recent years are listed, and the future directions for the development of dairy allergen modification and the future prospects of hypoallergenic dairy products. This review is expected to provide a theoretical basis and research ideas for the development of hypoallergenic dairy products in the future.

A high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was established to analyze glucose, sucrose, lactose, galactooligotrisaccharide, 1-kestose, galactooligopentosaccharide, nystose and 1F-fructofuranosyl nystose in four commercial brands of infant formula. The spiked recoveries of HPAEC-PAD ranged from 78.0% to 96.8% with relative standard deviation (RSD) of 4% (n = 5). Its limits of detection were between 3.0 and 12.0 mg/100 g. When HPAEC-PAD and the high-performance liquid chromatography (HPLC) specified in the Chinese national standard were applied to detect sucrose, lactose and 1-kestose in real samples, consistent results were obtained. However, the five other sugars were detected by HPAEC-PAD but not by HPLC. Accordingly, compared with HPLC, HPAEC-PAD was more sensitive and useful for the simultaneous determination of multiple sugars in infant formula.

The purpose of this study is to establish a simple, rapid and effective method for the simultaneous analysis of various saccharides (glucose, sucrose, lactose, galactooligotrisaccharide, kestose, galactooligopentasaccharide, nystose and 1F-fructofuranosyl nystose) in infant formula by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The effect of chromatographic columns, column temperature, detector waveforms, eluent concentration and flow rate on the separation of the 8 saccharides was evaluated. The analysis was performed on a CarboPac PA20 analytical column (3 mm × 150 mm) coupled with a guard column (3 mm × 30 mm) at a 0.30 mL/min flow rate. Column temperature was set as 30 ℃. Efficient separation was achieved using gradient elution. Under the optimal conditions, the detection limit was 3.0–12.0 μg/L for all analytes. The precision, expressed as relative standard deviation (RSD), was less than 3%. The recoveries of the 8 saccharides in spiked soymilk were 78.0%–96.8%, indicating the feasibility of this method.

This paper reviews the progress in the application of gas and liquid chromatographies, ion chromatography and liquid chromatography-mass spectrometry for the detection of carbohydrates in milk powder. It points out the advantages and disadvantages of these methods. While ion chromatography is nowadays the most used technique to detect carbohydrates in milk powder, ion chromatography will be an important trend in this field owing to its distinct advantages in terms of sensitivity and anti-interference ability.

In order to provide a deep understanding of flavor formation in cheese, this paper reviews the formation and metabolism of flavor compounds in cheese with respect to proteolysis, lipolysis, and lactase and citric acid fermentation. The focus of this review is on protein breakdown into short-chain peptides and amino acids by natural enzymes, chymotrylase, starter cultures, secondary starter cultures and non-starter microorganisms, the formation of lactone and butyric acid as metabolites during the enzymatic hydrolysis of fatty acids, the conversion of lactose into lactic acid by lactic acid bacteria, and the conversion of the intermediate pyruvate into diacetic acid and 3-hydroxy-butanone, acetaldehyde or acetic acid. Conclusively, the flavor substances of cheese mainly include fatty acids, esters, aldehydes, alcohols, ketones, sulfides, phenols and ethers.

In the present study, a preliminary purification was carried out to obtain heat-resistant lipase secreted by Pseudomonas fluorescens separated from fresh milk. Moreover, the effects of temperature, pH, and Ca2+ concentration on the activity of this lipase were determined. Results showed that the lipase from Pseudomonas fluorescens had a molecular weight 55 kD and a purity of 91.5% after the purification, and its relative activity was 75.02%, 86.21%, 73.25%, 17.62% and 13.63% after heat treatment at 50 ℃ for 30 min, 63 ℃ for 30 min, 72 ℃ for 20 s, 90 ℃ for 10 min, and 121℃, 0.1 MPa for 20 min, respectively. The optimum reaction pH and temperature for this enzyme were 8.0 and 63 ℃, respectively. The lipase activity was not significantly affected by Ca2+ concentration.

The structured management platform for food regulations can be coordinated with food product development to form a data management system. Dairy companies are able to establish a structured standard database of dairy product regulations dairy based on the official interpretation of the regulations. The development of dairy products should be strictly in conformity with the regulations by information-based means. By checking the matching between structured regulation data and product development data by information-based means, it can be ensured that dairy products are developed in accordance with the regulations and dairy enterprises can develop continuously and steadily.

Wheat germ is recognized as the treasure house and essence of nutrition, accounting for only 1.4%–3.9% of the dry weight of the grain. It is extremely rich in quality protein, fat and a variety of vitamins and minerals. In this study, CMC, citric acid, sugar and whole milk powder were used for formulating a wheat germ-based dairy beverage. By using one-factorat- a-time and orthogonal array design, the optimal formulation of the nutritional beverage was determined to consist of 0.08% CMC, 0.05% citric acid, 4% sugar and 4% whole milk powder.

The composition and content of amino acids in infant formula sold in China were investigated in comparison with human milk at different lactation stages. An amino acid analyzer was used to detect the contents of free and hydrolyzed amino acids in commercial infant formula, and total amino acid content and the proportion of individual amino acids were calculated. The results showed that free amino acids were detected in some of the 12 samples, while hydrolyzed amino acids were detected in all these samples. The average concentration of most amino acids was close to that of human milk at 1 to 60 d of lactation, and higher than that of human milk at 61 to 180 d. The average ratio of essential to total amino acids was 46.43%, which was close to that of human milk. The proportions of methionine and tryptophan to total amino acids were higher than those of human milk, the proportions of arginine and cystine to total amino acids were lower than those of human milk, and the proportion of other amino acids to total amino acids was close to that of human milk. This study reveals the difference in amino acid content between commercial infant formula and human milk.