To solve the difficulty of storing and transporting yak butter, yak butter microcapsule powders were prepared using a mixture of maltodextrin and sodium caseinate as the wall material, a mixture of molecular distilled monoglycerides and sucrose ester as the emulsifier and guar gum as the stabilizer by vacuum freeze-drying or spray drying. The basic physicochemical properties (moisture content, solubility, rheology, surface oil content, encapsulation efficiency, and yield), microscopic structure, and thermal stability of the two as-prepared samples were compared. The results showed that the microencapsulated powders prepared by the two methods were milky white in color and free of impurities, and had a fresh aroma. Both of them exhibited high encapsulation efficiency, (90.17 ± 1.07)% and (92.12 ± 0.32)%, respectively. The yield of freeze-dried microcapsule powders, (98.42 ± 0.38)%, was significantly higher than that of spray-dried microcapsule powders, (25.77 ± 1.34)%, and the average particle size (D[4,3] = 16.695 μm) was smaller than that of spray-dried powder (D[4,3] = 24.945 μm). The solubility and fluidity of the spray-dried powder were superior to those of the freeze-dried powder. Under a scanning electron microscope (SEM), the surface of spray-dried powder was smooth and spherical in shape, while the freeze-dried powder was irregular. The thermal stability of the spray-dried powder was better. In summary, when considering economic benefits, the spray-dried powder holds greater significance for industrial production.

Yogurt was prepared from raw milk and oolong tea powder with added L-theanine and muscovado sugar using a starter culture of lactic acid bacteria. The effects of the concentration of oolong tea powder, muscovado sugar and L-theanine and inoculum size on the pH value, acidity, viscosity, water-holding capacity and sensory score of yoghurt were investigated by using a combination of one-factor-at-a-time (OFAT) method and orthogonal array design (OAD). The results showed that under the conditions of 0.3% oolong tea powder concentration, 8% muscovado sugar concentration, 0.09% L-theanine concentration and 0.010% inoculum size, the sensory score, pH value, acidity, water-holding capacity, and total viable count of the prepared yogurt were 96 points, 4.54, 72 °T, 67.34%, and 5.78 × 109 CFU/g, respectively. The product had a rich flavor, bright color, exquisite texture, prominent muscovado sugar-like flavor, strong aroma, and smooth taste without suspended particles.

Milk protein is an important source of dietary protein for humans. In the modern food industry, milk and milk protein have become essential components in various processed foods. Milk protein is one of the most common allergens, and the problem of food allergies caused by milk protein has become a topical issue in the field of food safety. With the development of the dairy industry, non-milk derived food ingredients have been introduced in various dairy products, which may interact with milk protein, altering the protein’s structure and affecting its antigenic epitopes and consequently its allergenicity. Herein, we discuss the effects of food components on milk protein allergenicity from macronutrients, micronutrients and functional activities contained in the food base, and other substances. We hope that this review can improve the scientific understanding of milk protein allergenicity in food components, guide food processing safety to reduce milk protein allergenicity, and provide a basis for food allergenicity risk assessment.

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.

Lactic acid bacteria have commonly been used in fermented foods, which will exert health-beneficial functions only when reaching a certain population level. Some lactic acid bacteria have strict requirements on growth conditions, making it difficult for many fermented products to ensure a high number of viable bacteria within the shelf life. How to promote the proliferation of lactic acid bacteria and maintain its stability has become a research hotspot. This paper reviews the roles of functional oligosaccharides, polysaccharides, whey protein hydrolysate and plant-derived materials in promoting the growth of lactic acid bacteria. It has been demonstrated that some growth-promoting materials are useful for promoting high-density culture of lactic acid bacteria, ensuring a high number of viable cells in fermented dairy products during storage, and improving the functions of probiotic products.

Brown yogurt is a new type of yogurt with a burned flavor formed by the nonenzymatic Maillard reaction and silky smooth mouthfeel that contains high-quality nutrients and has become a new hotspot in the yogurt market. As Gansu province is one of the major livestock production areas and dairy processing bases in China, this region is bound to development the brown yogurt industry and seize market share. This article reviews the current status of the development of Gansu’s brown yogurt industry and existing problems. This review covers a summary of the history of the development of this industry and the problems encountered during the development process, the barriers to and driving forces for the research and development of brown yoghurt, the current status and challenges of brown yogurt processing, and the current trends and future prospects of brown yogurt.

Kombucha, also known as Haibao, is a traditional acidic tea beverage fermented by a symbiotic culture of lactic acid bacteria, acetic acid bacteria and yeast. Lactic acid bacteria (LAB) were isolated and purified from kombucha and the purified strains were identified. The results showed that a total of 4 LAB strains (XC, XD, XL and XQ) were isolated and they were all identified as Lactobacillus plantarum. These strains entered the stationary growth phase after 14 h. For all four strains, both the pH value and titratable acidity declined during their growth. The optimal inoculum size for XC, XD and XQ was 4%, while that for XL was 6%. The optimal growth temperature for these strains was 30 ℃ and none of them was resistant to salts. All these strains had different tolerance to bile salts and acidity and XQ was the most tolerant among them.

In order to find the difference between the cleavage sites in bovine milk proteins by metalloproteinase from Paenibacillus spp. BD3526 and chymosin, the peptides generated from αs1-, αs2- and κ-casein and β-lactoglobulin (β-Lg) digested by the enzymes were analyzed by high performance liquid chromatography coupled with quadruple-timeof- flight mass spectrometer (HPLC-Q-TOF-MS-MS). The results indicated that the cleavage sites in bovine milk proteins by metalloproteinase and chymosin shared high similarity and both of these enzymes specifically cleaved the Lys-Thr, Lys-Phe, Arg- Phe and Arg-Tyr peptide bonds to generate peptides with ACE inhibitory, antimicrobial and immunomodulating activities.

The objective of this study was to explore and compare the effect of different heat treatments on the stability of buffalo milk. For this purpose, milk samples were subjected to different heat treatments for the comparative determination of pH buffer capacity, total dissolved solids (TDS) content, the amount of protein precipitation and apparent viscosity. The results showed that the pH buffering capacity, TDS, protein precipitation and apparent viscosity of buffalo milk were significantly changed after heat treatments. After treatment at 121 ℃ for 15 min, the pH buffering capacity, TDS, protein precipitation and apparent viscosity reached their maximum levels, while pH buffering capacity and TDS were minimized after treatment at 95 ℃ for 5 min. Therefore, it was concluded that the stability of buffalo milk was most affected by treatments at 121℃ for 15 min and at 95 ℃ for 5 min in the experimental range investigated.

Phellinus baumii is a highly-valued medicinal mushroom. In the current study, inhibitory effects of different concentrations of the 95% ethanol extract from Phellinus baumii were examined on Gram-positive, Gram-negative, molds and yeasts. The results showed that the Phellinus baumii ethanol extract at concentrations in the range of 0.1 to 5 mg/mL was effective against the growth of harmful bacteria and fungi and could obviously control the total number of bacteria in milk without having any significant adverse impact on beneficial bacteria. Meanwhile, the extract had a broader antimicrobial spectrum than antimicrobials such as nisin, suggesting its potential application for inhibiting harmful microorganisms in milk and dairy products.

The dipeptidyl peptidase-Ⅳ (DPP-Ⅳ) inhibitory activity and physicochemical properties of yak milk casein hydrolysates produced with alcalase, papain and trypsin were investigated. The effect of hydrolysis periods and different proteases on the DPP-Ⅳ inhibitory activity of yak milk casein hydrolysates was assessed by DPP-Ⅳ inhibitory rate. The physicochemical properties of yak milk casein hydrolysates were evaluated by degree of hydrolysis, trichloroacetic acidnitrogen soluble index (TCA-NSI), solubility and ash content. Results showed that the DPP-Ⅳ inhibitory activity of yak milk casein hydrolysate obtained with papain was significantly higher than that of those obtained with alcalase or trypsin at the same hydrolysis period (P < 0.05). The yak milk casein hydrolysate obtained after 0.50 h hydrolysis with papain displayed the highest DPP-Ⅳ inhibitory activity (with inhibitory rate of (53.95 ± 1.57) %), higher extent of hydrolysis degree, and the lowest ash content. The results suggest that peptides with DPP-Ⅳ inhibitory activity can be generated from yak milk casein. The yak milk casein hydrolysate produced by papain may be used as a functional dairy ingredient to develop functional foods.

An HPLC method to determine dicyandiamide in milk and dairy products was proposed and validated in the present study. A comparative investigation of gradient and isocratic elution was carried out for the chromatographic separation of dicyandiamide. The results of this study indicated a good linear relationship for dicyandiamide over the concentration range of 0.1002 to 10.0200 μg/mL under gradient elution conditions (r = 0.9996). The average recovery of dicyandiamide was 92.8%, and the limit of detection was 0.01 μg/mL. This method proved to be applicable for the determination of dicyandiamide in milk and dairy products.