With the development of China, children’s cheese has garnered increasing attention in the dairy industry, which has become a new growth point of China’s dairy industry. However, children’s cheeses currently available on the market are uneven, which cannot be fortified completely according to children’s nutritional needs. Their tastes are similar and their selling points are the same, which causes the public’s sensory fatigue and also go against consumers’ pursuit of clean label. Thus, the development of the children’s cheese industry is facing new challenges. In this paper, from the perspectives of children’s health and cheese nutrition, we link the needs of children of different ages for nutrition, flavor and texture with the nutrition, flavor and texture of cheese. The present situation, challenges and possible development directions of children’s cheese food in China are summarized.

Vanillin is a flavor widely used in the food industry. This paper discusses the application of vanillin in the food industry, worldwide limits for the use of vanillin, the characteristics of the production technology and the possible risks brought by vanillin for foods, and it also summarizes the methods for vanillin detection in dairy products, infant formulas and formulas for special medical purposes intended for infants including gas chromatography (GC), liquid chromatography (LC), gas chromatography-tandem mass spectrometry (GC-MS/MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and spectroscopy with special attention to their advantages and limitations. This review is expected to provide a basis for the detection and further research of vanillin in infant formulas for special medical purpose.

Yak milk is a characteristic resource in the Qinghai-Tibet Plateau of China. It has incomparable characteristics with other milks and has the potential to be developed into high-quality dairy products. In recent years, intensive research efforts have been made to investigate yak milk, but the development and utilization of yak dairy products in China is not perfect yet. This paper summarizes the latest progress in the development of processed yak milk products such as fermented milk, Qula, whey, cheese and butter, aiming to clarify the existing framework system of yak milk processing, find out the potential research directions and develop new yak dairy products. It is expected to provide scientific reference for the further development and utilization of yak milk resources and promoting economic development in the Qinghai-Tibet Plateau.

Hydrolyzed protein formula not only solves the problem of allergy or intolerance to cow’s milk proteins in infants and young children, but also meets the nutritional needs. Degree of hydrolysis is an important parameter to evaluate hydrolyzed protein formula. However, there are currently no methods available to determine the degree of hydrolysis of hydrolyzed protein formula. This article presents a brief introduction to the basic concepts of hydrolyzed protein formula and its degree of hydrolysis, and summarizes the existing methods for detecting the degree of hydrolysis of proteins. We expect this review to provide a reference for the establishment of detection methods for the degree of proteolysis of hydrolyzed protein formula.

Ion chromatography was used to determine the inositol content in formula foods for special medical purposes. The sample was acidified by hydrochloric acid to precipitate proteins, and inositol was dissolved in the supernatant and then detected with an amperometric detector. The results showed that the peak area was linearly related to the concentration of inositol in the range of 0.025 to 40.000 mg/L with a correlation coefficient (R2) of 0.999 9. The detection limit and quantitation limit were 0.125 and 0.5 mg/100 g, respectively. The average recovery of inositol was 83.1%–102.9% at different spiked levels. The method was proved to be simple, sensitive reproducible and suitable for the determination of inositol in formula foods for special medical purposes.

In this study, the applicability of hydride generation atomic fluorescence spectrometry (HG-AFS) and inductively coupled plasma mass spectrometry (ICP-MS), methods I and III specified in the national standard GB 5009.93—2017, respectively to detect selenium in infant formula for special medical purposes was researched. Seven laboratories separately determined the selenium content in six samples of 3 types of infant formula for special medical purposes and infant formula quality control samples, and measured the recoveries. The results showed both methods were suitable for the determination of selenium in infant formula, while the applicability for various types of infant formula foods for special medical purposes needs to be further studied.

In order to establish an efficient method for the determination of L-carnitine in infant formula for special medical purposes, the spectrophotometric method for the determination of L-carnitine in foods for infants and young children and dairy products specified in the national standard GB 29989—2013 was optimized with respect to standard curve preparation, sample pretreatment and enzyme preparation. The results showed that under the following conditions: using the optimized standard curve, enzyme extraction at a rotation speed of no less than 6 000 r/min, and hydrolysis of 5 g of homogeneous milk powder (accurate to 0.000 1 g) with 0.25 g of α-amylase at 50 ℃ for 30 min, the optimized method exhibited high precision and spiked recovery. This method could overcome the problems encountered in the determination of L-carnitine in infant formula for special medical purposes by the traditional method such as cloudy filtrate, the dark color of prepared samples that could interfere with the determination of absorbance and low spiked recovery, being suitable for the large-scale determination of L-carnitine in amino acid-based infant formula, extensively hydrolyzed protein infant formula and partially hydrolyzed protein infant formula for special medical purposes.

The applicability of silver nitrate titration and potentiometric titration, two of the three detection methods for chlorine in food samples specified in the national standard GB 5009.44—2016, for infant formula for special medical purposes was evaluated. The results showed that the spiked recoveries of silver nitrate titration for partially hydrolyzed protein infant formula, extensively hydrolyzed protein infant formula, and amino acid-based infant formula for special medical purposes were 95%–108%, 98%–125% and 100%–106%, respectively, and the relative standard deviations (RSD) for precision were between 12.7% and 32.9%. The results of potentiometric titration was lower than that of silver nitrate titration.

This research investigated the effects of reconstitution pH value and temperature, storage duration, sunlight exposure and reheating on the contents of vitamin B1 and vitamin D in six different kinds of formula foods for special medical purposes sold on the market. The results showed that the vitamin B1 content decreased with increasing reconstitution pH value and temperature and storage time, but was little affected by reheating. The vitamin D content decreased with storage time in sunlight. pH value and reheating had little effect on the content of vitamin D. The optimum conditions for ensuring the highest utilization ratio of vitamin B1 and vitamin D in formula foods for special medical purposes were reconstitution in acidic water (pH < 7) at 40–60 ℃, storage in darkness and preferably use immediately after reconstitution.

A total of 15 food-grade Lactobacillus strains were evaluated for their antagonism against gastrointestinal pathogens using Bifidobacterium animalis subsp. lactis BB-12 as a control. The results showed that nine of the strains possessed excellent antibacterial properties against five indicator bacteria tested, and two of the remaining six strains were antagonistic against four of the indicator bacteria, Staphylococcus aureus, Salmonella, E. coli and Bacillus cereus. According to their antagonistic effect, acid producing ability and milk curding ability, four strains were selected and each of them was combined with Streptococcus thermophilus ST-21 for use as bio-preservative starter cultures. Streptococcus thermophilus ST-21 + strain Z-38 at a ratio of 2:1 could produce acid rapidly, have potent post-acidification capacity and produce a strong milky aroma, being suitable for the production of flavored yogurt. Streptococcus thermophilus ST-21 + strain Z-40 at a ratio of 2:1 resulted in the best texture of yogurt, being suitable for the production of fermented dairy drink. Yogurt fermented by Streptococcus thermophilus ST-21 + strain Z-12 at a ratio of 1:1 showed the lowest consistency and cohesiveness.

The growth, acid production and changes in viable cell count of 8 strains of Leuconstoc mesenteroides were measured in chemically defined medium (CDM) with different carbon sources or skim milk. The results showed that there were significant differences in the growth of these strains in CDM with lactose or galactose as the single carbon source. Strains LM1, LM2, LM4 and LM8 grew well in CDM with lactose as the single carbon source. Strains LM2, LM3, LM5 and LM8 had stronger vitality in CDM with galactose as the single carbon source, but their growth was weaker than that in the presence of lactose. In skim milk, the viable cell count of all experimental strains increased obviously in the early fermentation stage. After 8 h, their growth entered the stable phase, and the pH value at the end of fermentation was above 6.0. While the differences in genes related to lactose and galactose metabolism were preliminarily compared among the strains in this study, the correlation between genes and phenotypes needs to be further analyzed based on lactose hydrolase activity and lactose and galactose residues.

As a nutritional supplement for people with special needs, the food for special medical purposes (FSMP) has occupied an important position in the global market. As the main source of added nutritional components in FSMP, nutritional fortifiers are of great significance to improve its quality. This paper focuses on the comparative analysis of the standards and regulations of the Codex Alimentarius Commission (CAC), the EU and China on nutrients and nutritional fortifiers in FSMP with respect to limits, ingredients, sources, and so forth, in order to provide useful information for improving the standards for the use of nutritional fortifiers in FSMP in China.

This study describes the optimization of the formulation of cryoprotectants for Bifidobacterium lactis Z-1 using response surface methodology (RSM). Using the Plackett-Burman design, trehalose, sucrose, L-cysteine hydrochloride concentration were identified as factors with a significant influence on the viable count of lyophilized Bifidobacterium lactis Z-1. Subsequently, the optimal response ranges of the three factors were determined using the steepest ascent method. The levels of these factors were further optimized using RSM with Box-Benhnken design. As a result, a regression model was fitted into the experimental data. The optimal levels of trehalose, sucrose and L-cysteine hydrochloride were determined as 200.51, 46.16 and 2.31 g/L, respectively, while the other ingredients were the same as those in the traditional recipe (skimmed milk powder 100 g/L, whey protein powder 20 g/L, glycerol 4 g/L, sodium isoascorbate 10 g/L and sodium glutamate 8 g/L).

A total of 30 food-grade Lactobacillus strains isolated from naturally fermented products from Tibetan, Xinjiang and Qinghai regions including Lactobacillus rhamnosus LGG (as a control) were evaluated for acid and bile salt tolerance, hydrophobicity, surface charge and auto-aggregation ability. Out of these, 16 strains were selected and further evaluated for tolerance to artificial gastric and intestinal fluids. The results showed that the survival rates of 4 of the 16 strains were greater than 14.44% after 60 min of incubation in artificial gastric fluid and were 3.91%–100.00% after 30 min. For all 16 selected strains, the survival rate was 31.73%–112.83% after 5 h, and Z-1 had the strongest tolerance to artificial gastric fluid of these strains with a 93.07% survival rate after 60 min. The survival rate of Z-1 was 106.5% after 5 h of incubation in artificial intestinal fluid, hydrophobicity 97.52%, surface charge 97.35% and 24.67% in the presence of chloroform and ethyl acetate, respectively, and auto-aggregation ability 11.26%.

Human milk oligosaccharides (HMOs) are important components in human milk. Understanding the differences between non-HMOs and HMOs is fundamental to develop infant formula with improved nutritional functions making it more similar to human milk to satisfy the nutritional health of infants. This paper reviews the types and structural characteristics of HMOs and their roles in regulating the intestinal microflora, improving intestinal health and promoting immune system development. Meanwhile, the differences between the composition of oligosaccharides in mammalian milk and HMOs composition are described, as well as the characteristics and functions of oligosaccharides commonly used in infant formula. The problems associated with the application of oligosaccharides in infant formula are proposed and future prospects are discussed. We expect that this review will provide a theoretical guidance for the development of new infant formulas.

Goat milk is rich in a wide variety of nutrients and has prominent nutritional and functional properties. Because of its nutritional similarity to breast milk, goat milk is an emerging alternative milk source for infant formula to bovine milk. Nowadays, there is a worldwide interest in the safety and nutritional value of goat milk products. This article presents a discussion of the nutritional composition, safety and functional characteristics of goat milk, indicating that goat milk has great advantages for use as a milk source for infant formula. Goat milk is rich in a variety of nutrients including protein, fat, carbohydrates, vitamins and minerals and contains active substances such as superoxide dismutase and epithelial cell growth factors, protecting against viruses and tuberculosis infection with good safety. Infant formula made from goat milk has a reduced allergenicity and increased digestibility, and can enhance fat absorption rate and lower cholesterol levels.

A method was developed for the simultaneous determination of 2 ultraviolet absorbers UV-326, UV-1577 and 2 antioxidants AO-1010 and AO-2246 in milk by high performance liquid chromatography. Samples were extracted with acetonitrile. The effective separation of the target analytes was accomplished on Agilent HC-C8 (150 mm × 4.6 mm, 5.0 μm) column with gradient elution procedure using a mixture of water and acetonitrile as the mobile phase. External calibration was used for quantitative determination at detection wavelength of 280 nm. The linearity of 4 analytes were satisfactory with a correlation coefficient of > 0.9995 at concentrations ranging from 0.05 to 50 μg/mL. The limits of detection of the method were 0.02?0.5 mg/kg, and the recoveries at different spiked levels and precision (RSD) were 69.08%?115.87% and 0.43%?9.94%, respectively. The method is simple, sensitive, reproducible and suitable for the simultaneous determination of 2 ultraviolet absorbers and 2 antioxidants in milk.

Nowadays, the Chinese dairy industry is developing fast. Dairy products have become an important part in people’s dietary structure. Functional dairy products are an emerging type of dairy products which exerts physiological effects through added probiotics and bioactive molecules. The present article presents an overview of China’s dairy products market and analyzes the classification, market and consumption conditions, current status and limitations of functional dairy products. Moreover, some suggestions regarding the development trends of functional dairy products in China are given based on the development of related products and technologies worldwide. This paper can provide useful references for the research and development of functional dairy products.

Lactoferrin is an important multifunctional protein that has a variety of biological activities, such as anti-bacterial, anti-tumor, anti-allergy, immunoregulatory and so on. The related basic research and application development of lactoferrin have attracted wide attention. Therefore, the detection methods for lactoferrin have drawn increasing attention. Especially the advantages, sensitivity, accuracy and stability of different methods vary to different extents, which directly affects their applicable scope. The present paper has described the detection methods which have been reported to be suitable for different types of biological samples, mainly including spectrophotometry, high performance liquid chromatography (HPLC), enzyme-linked immunosorbent assay (ELISA), high affinity chromatography (HPAC), efficient capillary electrophoresis (HPCE) and surface plasmon resonance (SPR). The advantages and disadvantages of these different detection technologies also have been analyzed and compared. This review is expected to provide reference for selection of the suitable detection method for lactoferrin in research and development practices.

The solubility of milk protein concentrate (MPC), which has a direct impact on its application value, may be reduced during storage. The effect of ultrasonic treatment with different powers for different durations on the solubility of fresh and stored MPC was studied. The results showed when stored MPC85, a commercial product, was treated with ultrasonic (at 50, 300 or 600 W for 5 min, or at 300 W for 3, 5 or 10 min), its solubility decreased sharply. As for fresh MPC70 stored for 30 d after treated with ultrasonic (at 300 or 600 W for 3, 5 and 10 min, respectively), its solubility decreased slowly and the smallest decrease was observed upon ultrasonic treatment for 300 W, 10 min. Ultrasonic treatment is useful to retard the decrease in the solubility during storage of MPC.

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.