Protein is an important nutrient in the food system, and active ingredients (such as polyphenols, flavonoids, and terpenes) have a variety of physiological effects because of their unique chemical structures, such as antioxidant, antitumor, and chronic disease-preventive effects. They form complexes through covalent or noncovalent interactions, thus changing their functional structure, nutritional properties, and bioavailability. In this review, we summarize the application of multispectral methods, including ultraviolet-visible (UV-vis) absorption, fluorescence, Fourier transform infrared (FTIR), circular dichroism (CD) spectra, and molecular simulation techniques (molecular docking and molecular dynamics simulation) in the study of protein-active ingredient interaction. The principles, features, and examples of these techniques in the study of the interaction between protein and active ingredients are briefly described. This review also focuses on the application of molecular simulation in delivering active ingredients, regulating food flavor, and monitoring food quality based on protein-active ingredient systems, hoping to provide scientific reference for further study of the interaction between protein and active ingredients.

In order to explore the key factors for the nutritional quality evaluation of raw milk in Shanghai, a total of 167 batches of raw milk were collected from 11 large-scale dairy farms in Shanghai from July 2022 to March 2023, and their amino acid composition, fatty acid composition, vitamins, lactoferrin and trace elements were detected. The amino acid composition data were analyzed by means of principal component analysis (PCA) and the proportions of various fatty acids were compared. The results showed that 16 amino acids, 26 fatty acids, active factors including lactoferrin, α-lactalbumin and β-lactoglobulin, and 9 essential trace elements were detected in raw milk. On this basis, we selected 13 key factors for the nutritional quality evaluation of raw milk, which could provide an important reference for the further screening and utilization of raw milk sources in Shanghai.

As the most common type of anemia, iron-deficiency anemia has attracted more and more attention. With the change of nutrition and health needs and the enhancement of safety awareness, there has been increasing interest in the research and development of oral iron supplements with good iron supplementation effect, easy absorption, small side effects and high safety. This paper reviews recent progress in the development and research of iron supplements. In this paper, the raw material source, structure, action mechanism, preparation, application, and digestion and absorption mechanism of iron protein succinate are reviewed, and future prospects of polypeptide-iron complexes and iron protein succinate are discussed. We anticipate that this review will provide a theoretical basis for the research and development of iron supplements.

This study was conducted to reveal the effect of milk-clotting enzyme (MCE) produced by Bacillus licheniformis on the texture of Cheddar cheese during ripening. Cheddar cheese and Cheddar cheese analogue were prepared with the MCE and designated as CDF and CD3, respectively, and commercial chymosin was used as a control (CCF).The changes in the texture, rheology and microstructure of cheese during ripening were analyzed. The results were as follows: The hardness of the three cheeses increased with maturation time, while the elasticity and chewiness presented a downward trend. The hardness, springiness and chewiness of CDF were the lowest. The scanning electron microscope (SEM) results showed that the compactness of the protein structure decreased with increasing maturity, and the structure of CDF was looser than that of CCF. The rheological results showed that the storage modulus and loss modulus decreased with increasing ripening time up to six months and increasing sweep temperature. The tan δ value decreased during the ripening process, indicating that the fluidity of cheese decreased with increasing ripening time. The fluidity and fusibility of CDF were better than those of the other groups. The above results indicated that the mechanical properties of cheese made with Bacillus licheniformis MCE were better than those made with commercial rennet, while the latter had harder texture and denser protein network structure.

The impact of adding polysaccharides extracted from liquid-cultured mycelia of Inonotus obliquus into yak yogurt on its sensory evaluation score and titratable acidity was investigated to determine the optimal addition amount of the polysaccharides. The process parameters for producing yak yogurt with added Inonotus obliquus polysaccharides were optimized, and the quality of the yogurt prepared under optimized conditions was evaluated and compared with that of yogurt without added Inonotus obliquus polysaccharides as a control. The results showed that addition of 0.4% Inonotus obliquus polysaccharides to yak yogurt led to the highest sensory score together with a moderate acidity. Using orthogonal array design, the optimal process conditions were determined as follows: ratio of Streptococcus thermophilus G2 to Lactobacillus paracasei L9, 1:1; fermentation time, 14 h; temperature, 38 ℃; and sucrose concentration, 8 g/100 mL. Compared with the control, the as-prepared yogurt increased the number of viable lactic acid bacteria, titratable acidity and water-holding capacity by 34.1%, 11.0% and 16.8% respectively, and the pH value decreased accordingly. Addition of Inonotus obliquus polysaccharides into yak yogurt improved its firmness and viscosity as well as flavor.

Molecular biology studies have confirmed that bioactive polysaccharides are naturally occurring polymers that have a variety of physiological and biochemical functions. The water-complexing ability, high viscosity, antioxidant and anti-aging properties of bioactive polysaccharides lay the foundation for their application in the fields of food, and the use of bioactive polysaccharides as a bioactive ingredient in functional foods has become a current research focus. Fermented milk has good flavor and probiotic properties, but it also has the disadvantages of short shelf life, poor curd quality, and general probiotic performance. How to improve the quality of fermented milk is a current major challenge. This article focuses on recent progress in the application of different types of bioactive polysaccharides in fermented milk, and reviews the effects and mechanisms of action of bioactive polysaccharides on the physicochemical, gel and probiotic properties of fermented milk. Furthermore, it discusses future prospects for the application of bioactive polysaccharides in fermented milk. This review is expected to provide a reference for exploring the functions of bioactive polysaccharides and improving the quality of fermented milk.

Tea polyphenols, secondary metabolites found in green tea, are widely used in the food and medicinal industries because of their antioxidant and anti-cancer activity and preventive effect against cardiovascular diseases. The interaction of tea polyphenols with milk proteins can alter the structure of milk proteins and further affect the functional properties and bioavailability of dairy products. There have been widespread concerns about the binding of phenolic compounds to milk proteins due to the special structures of milk proteins. This review describes the mechanism of polyphenol-milk protein interaction, the factors influencing this interaction, the characteristics of reaction products, the methods used to analyze the mechanism, and the effects of this interaction on the functional properties and bioavailability of dairy products. Through this review, we aim to lay a theoretical basis for the development of new products based on the combination of tea polyphenols and milk proteins.

This study aimed at the application of Wolf formula for structural design of corrugated box for dairy products. Five kinds of corrugated boxes for 350 mL of Momchilovtsi, a Bright Dairy yoghurt brand, were designed according to the capacity and arrangement of the inner packaging, and their theoretical compression strength was calculated using Wolf formula as well as their minimum compression strength when 10 boxes were stacked and stored in the same environment using compression formula. Comparative analysis of the results of both calculations was carried out based on structural design elements such as ratio of length to width and length of sides. Moreover, verification was achieved using compression tests. Finally, we established the optimal structural design of 350 mL corrugated boxes for Momchilovtsi. It was showed that corrugated carton No. 4 had the highest marketability under the conditions: the same material and height, 3 × 3 arrangement mode, length/width ratio of 1, and length of sides of 74 mm.

Three kinds of aluminum-free composite sealing film: F1, polyethylene/low density polyethylene/ethylenevinyl acetate copolymer (PE/LDPE/EVA); F2, polyethylene terephthalate (PET)/PE/EVA; and F3, PET/cast polypropylene (CPP)/ EVA were selected to package yoghurt in polystyrene (PS) cups. Comparison of material characteristics and packaging performance of composite films and the storage life of packaged yoghurt was carried out with respect to fim oxygen permeability, opening force and puncture resistance, and yoghurt sensory evaluation, acidity and storage life. The storage life of yoghurts packaged with F1, F2 and F3 was tested at (30.0 ± 1.5), (25.0 ± 1.5) and (4.0 ± 1.5) ℃, respectively. The results showed that oxygen permeability of F3 was the lowest, 46.602 cm3/(m2·24 h·0.1 MPa), among three kinds of films at the same temperature and humidity, and it had the best oxygen barrier property, while oxygen barrier property of F1 was the lowest. The storage temperature of (4.0 ± 1.5）℃ had less significant impact on the sensory evaluation, acidity or storage life of yoghurt than (30.0 ± 1.5) and (25.0 ± 1.5) ℃ and gave the longest storage life of 7 to 8 days, yielding an acidity higher than 87 °T at the end of the storage life. Under the same storage conditiuons (time and temperature), yoghurt packaged with F3 had the lowest acidity and exhibited the loweest growth rate of acidity and the best sensory evaluation results. In terms of opening force, only F2 and F3 met the packaing requirements for yoghurt. F1 had very high puncture resistance while F3 was the easiest to puncture with an ease level of 85%. Together, the above fingdings demonstrate that PET/CPP/EVA film is the most suitable sealing film for packaging yoghurt in cups, which achieves the longest storage life of 8 days at (4.0 ± 1.5) ℃ and meets the packaging requirements for yoghurt.

This study compared fermentation, membrane and washing as three detection methods for contaminating microbes in precast plastic containers for dairy products at different storage periods and at different degrees of contamination. Filtration and washing were more effective sampling means and could provide a better understanding of microbial contamination in the plastic containers than fermentation. However, filtration was unsuitable for high-level contamination. Therefore, the washing method is more suitable for large-scale detection in industrial practice.

Objective: A loop-mediated isothermal amplification (LAMP) assay was designed for rapid and accurate detection of Bacillus cereus in yogurt. Methods: Two pairs of oligonucleotide primers exclusively amplifying the hblA gene of Bacillus cereus were designed and Bacillus cereus could be directly detected by LAMP in yogurt, and the amplification products were detected by electrophoresis. Results: Detection of Bacillus cereus in yogurt by the LAMP assay was highly specific, the sensitivity was 6.4 CFU/mL, and the detection limit was 21 CFU/mL. Conclusion: The LAMP was fast, sensitive and useful for the detection of Bacillus cereus in yogurt.

A composite beverage was developed from milk with the addition of rice bran protein. Its formulation was optimized by one-factor-at-a-time and orthogonal array design to obtain the best sensory quality and emulsion stability. Meanwhile the storage stability of the composite beverage was investigated. The optimal formulation was found to consist of 2% whole milk powder, 0.7% rice bran protein, 10% white sugar, 0.3% citric acid and 0.2% composite stabilizer. The resulting product had a delicate taste and high nutritive value, and its emulsion stability and protein content were 97.52% and 1.0%, respectively.

In this paper, we use a three-level orthogonal array design to optimize fermentation conditions for the development of a cereal yogurt fortified with mango pulp. The results showed that yogurt which was evaluated to have a tender and smooth texture and a unique refreshing flavor was produced by addition of 8% of sugar, 2.5% of cereal flour, 0.15% of gelatin, 0.40% of modified starch and 0.15% of pectin to raw milk, inoculation of 250 DCU/t of DVS lactic acid bacteria and fermentation at 42.5 ℃ for 5 h followed by addition of 10% of mango and cooling with stirring.