In this study, Lactobacillus paracasei LZ9077 was used as a test strain to investigate the application of this bacterium and commercial fermenter agents in fermented milk. The acid production ability, the number of live bacteria, sensory evaluation and other evaluation indexes were used for process optimization. The optimal fermentation conditions were obtained by single factor test and orthogonal test, and the changes of yogurt during fermentation were determined. The results showed that the optimal fermentation conditions were as follows: the inoculum amounts of L. paracasei LZ9077 and commercial fermenter were 4% (V/V) and 0.1% (m/V), respectively, and the fermentation time was 6 h. The addition of L. paracasei LZ9077 increased the number of viable bacteria and the acid-producing efficiency of the fermented milk, and the number of viable bacteria was up to 9.22 (lg (CFU/mL)) at the end of the fermentation, and the titration acidity was (99.94 ± 0.36) °T, and the viscosity and stability of yoghurt were significantly improved.

Immunoglobulin G (IgG) and lactoperoxidase are bioactive components with high thermal sensitivity in milk. In this study, the changes in the IgG content and lactoperoxidase activity of milk during pasteurization and shelf-life storage were investigated. The results showed that homogenization temperature below 65 °C and homogenization pressure between 15 and 25 MPa had little effect on the two bioactive substances in milk. The combination of 72–76 ℃ and 15 s better retained the bioactive substances and membrane filtration was more effective than regular pasteurization in reducing the microbial load of milk. The IgG content and lactoperoxidase activity in pasteurized milk did not decrease significantly with storage time; however, long-term exposure to light could cause partial inactivation of lactoperoxidase in products with transparent packaging.

In recent years, plant-based yogurt has gradually entered the consumer market, and has attracted the eyeballs of consumers with health concepts such as lactose-free and low-cholesterol. At present, the US, the EU and China all regulate plant yogurt as beverages. The U.S. Food and Drug Administration has planned to formulate and release industry guidelines for plant-based milk and yoghurt, while EU regulations prohibit the use of the concept of plant-based yoghurt. In China, this concept has not been written into relevant national standards or industry standards. However, as a new product, plant-based yogurt has the advantages of plants themselves, and its nutritional value can be improved after fermentation. Therefore, relevant standards and regulations should be formulated as soon as possible to regulate the market. In this paper, by comparing the relevant regulations and standards of the US, the EU and China and in view of the particularity of plant-based yogurt, some suggestions on the management of regulations on plant-based yogurt are proposed.

The commercial food products with health claims of probiotics in China are mainly milk powder, yogurt, Lactobacillus containing beverage and probiotic powder. This research was concerned with the species of probiotics used and health claims of probiotics on the front and back sides of the packaging. A comparison of regulations on health claims of probiotics in China and abroad was carried out, and some suggestions for solving problems in the management of probiotic health claims were proposed. The results showed that different probiotics are used in various products. Modified milk powder generally contain 1–2 probiotic species, while Lactobacillus containing beverage, yogurt and probiotic powder mostly contained more than two probiotic species, some of them containing over ten probiotic species. The health claims of probiotic products mainly involve “probiotics”, “activity”, “name of strains”, “source of strains”, “amount of strains added and colony number”, “fermentation time”, “patent” and “intestinal health” on the front side of the packaging, and identical health claims or no health claims are made on the back side.

Human milk oligosaccharides (HMO) have complex structures and selectively stimulate the growth of probiotic bifidobacteria in the intestine of breast-fed infants. Infant gut-associated bifidobacteria provide molecular tools to metabolize HMO with strain specificity, such as glycosyl hydrolases. This review summarizes the structure of HMO and the mechanism underlying HMO metabolism by infant gut-associated bifidobacteria. The focus of this review is on the current advances in the intraspecific differences in bifidobacterial HMO metabolism and the tools involved in the metabolic process.

Lactobacillus plantarum is a ubiquitous microorganism, and as a member of the probiotic family it owns various probiotic functions including regulating the balance of the intestinal flora, maintaining normal immune response and lowering cholesterol levels, and has a broad application in the food industry. This article aims to review the mechanism underlying the health benefits of typical strains of Lactobacillus plantarum and to assess the factors limiting the application of Lactobacillus plantarum in the dairy industry.The commonly used solutions are presented.Hopefully,this review will provide a useful basis for practical application of Lactobacillus plantarum.

This paper reviews the current status of allergen labelling for domestic and imported dairy products and compares the domestic and oversea regulations on food allergen labelling. The aim is to put forward some suggestions on solving the problems existing in food allergen labelling management in China. Our comparison reveals that the rate of allergen labelling is very low for both domestic and imported dairy products and there are shortcomings in terms of location, terms and emphasis of contents. Furthermore, 60.0% domestic dairy products and 55.6% imported dairy products label the allergens below the ingredients. Foreign brands prefer to use "allergenic" or "sensitizing" as the leading terms in allergen descriptions. Only two brands at home and abroad emphasize allergen labelling using bold font or a different font color.

A comparison of six brands of imported Camembert cheeses was carried out to determine the differences in proteolysis and biogenic amine contents. Moisture content, pH value and free amino acid content of cheese samples were measured, and the degree of proteolysis was analyzed using the Kjeldahl method. Biogenic amine contents were measured using high performance liquid chromatography (HPLC). The results showed that there was a significant difference in pH value, proteolysis index and free amino acid contents among six brands (P < 0.05), with different degrees of ripening. Cheese pH value was positively correlated with proteolysis index. A significant difference in biogenic amine contents was also found (P < 0.05), but all samples were within the recommended limit. Among these, the sample FRA1 exhibited the highest degree of proteolysis and highest degree of maturation.

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that causes abdominal pain, diarrhea and constipation, reducing the quality of life in patients. Probiotics have been shown to regulate the intestinal flora balance, enhance intestinal barrier function and modulate the immune response, thereby providing new approaches to treat IBS. This article aims to review the literature concerning the treatment of IBS with probiotics with respect to the subtypes of IBS, changes in the intestinal flora of IBS patients, the therapeutical effect of probiotics on IBS and the underlying mechanism for the purpose of providing useful information for applying probiotics to treat IBS and broadening their scope of application.

The free fatty acid and volatile flavor compositions of six brands of imported Camembert cheese in China were measured comparatively by gas chromatography-mass spectrometry (GC-MS) and headspace solid phase microextraction (HS-SPME) combined with GC-MS. The results showed that all analyzed samples had an identical free fatty acid composition, myrisitc, palmitic, linoleic, and stearic acid being the major ones and no significant difference among the total free fatty acid contents of the six samples was found. On the other hand, a significant difference was noted in the contents of volatile flavor compounds, the samples FRA1 and FRA2 containing the highest contents of carboxylic acids while the remaining samples having higher contents of ketone compounds, which may be related to the maturity of cheese. Sensory evaluation of FRA1 and FRA2 showed lower scores for sensory attributes and overall quality, while the other four samples showed no significant difference.

Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB), with a variety of physiological functions, play a significant role in the improvement of physical properties of fermented dairy products. The structures and functions of EPS synthesized by different LAB strains are highly diverse. Therefore, this review summarizes the progress that has been made in recent years in studying the structure of EPS from LAB and its effect on physical properties and health-beneficial functions of fermented dairy products, in order to lay a theoretical foundation for developing new fermented dairy products with stable quality and desired health-beneficial functions.

The growth promoting effect of the supernatant of fermented skim milk with Paenibacillus spp. BD3526 on Lactobacillus plantarum ST-Ⅲ inoculated into skim milk was analyzed in this study. The results showed that the supernatant of BD3526 cultured in skim milk for 5–9 d significantly promoted the growth of ST-Ⅲ in skim milk and exhibited high milkclotting activity. After ST-Ⅲ was cultured in skim milk added with the supernatant of BD3526 for 24 h, the pH value decreased from 6.44 to 4.70–5.08, and milk clotting was observed at 16 h along with a viable cell count of 9.22–9.35(lg(CFU/mL)).

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.

Caseins were separated from the fresh milk of grazing yak cows in Tianzhu county, Gansu province by microfiltration to investigate changes in their heat stability, hydrophobicity, particle sizes and molecular weights after different pH treatments (pH 6.4, 6.6, 6.8 and 7.0) and heat treatments (80, 100, 120 and 140 ℃). The results showed that functional properties of yak milk caseins at pH 6.8 revealed the most significant deterioration after each heat treatment. At a temperature far below the denaturing temperature the caseins exhibited good retention of functional properties. Both acid and heat treatments caused molecular polarization of the caseins, destroyed the hydrophobic force, which contributes to maintaining the spatial structure of the protein molecules, and accordingly induced their dissociation or aggregation, causing changes in their molecular structure and in turn affecting their functional properties.

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.

3e

ε-Polylysine is widely used as a natural biological preservative in meat, dairy products and other foods for its characteristics of high safety, stability, efficiency, solublity in water and broad-spectrum antibacterial activity. In this paper, physiological and biochemical characteristics of Streptomyces albulus UN2-71, a strain capable of producing ε-polylysine, were studied. The ε-polylysine production increased from 1.64 to 2.37 g/L after optimization of fermentation conditions. The optimized conditions were defined as: 30 mL of the liquid medium in a 250 mL shake flask, inoculum size 10%, temperature 30 ℃, shaking speed 150 r/min and initial fermentation pH 7.0.

The textural properties of cheese samples with different hardness, including three kinds of hard cheeses and two kinds of soft cheeses, were measured by using a texture analyzer and the rheological parameters of the same samples were evaluated by using a rheometer to compare the rheological and textural properties of all the cheeses. Result showed that there was a significant difference in physicochemical properties (P ＜ 0.05), including pH, moisture content and water activity, between hard and soft cheeses. Hardness was significantly higher in hard cheeses than in soft cheeses. Hardness of all the cheeses obtained by TPA analysis correlated well with viscoelastic moduli. The dynamic analysis showed that all these cheeses manifested a more solid-like form. The rheological parameters were dependent on the oscillatory frequency. The differences of viscoelastic moduli between soft and hard cheeses were probably attributed to different amounts of moisture content and different levels of proteolysis. Hard and soft cheeses were significantly different through texture and rheology analysis. Viscoelastic moduli in the frequency range of 0.1 to 75 Hz could be used as a measure to distinguish among five kinds of cheeses.

In this study, white yak’s milk samples from three pastoral areas in Tianzhu county, Gansu province, collected at four different growth stages (withering, the final stage of withering, reviving and green) of forage grasses as well as from female yaks of different parity were analyzed by GC–MS for fatty acid composition. The results showed no significant difference in fatty acid content of yak’s milk among three pastoral areas or among 5 parities (P ＞ 0.05). The SFA:USFA ratio of yak’s milk at the withering stage, the final part of withering, the reviving stage and the green stage was 1.86, 1.75, 1.62 and 1.32, respectively. Lower amounts of SFAs but higher amounts of USFAs were found in white yak’s milk as the temperature increased and forage became more mature.

The present study aimed at understanding the storage stability of bovine colostrum whey powder. Moreover, a predictive equation to estimate its shelf life under the conditions of ambient temperature (25 ℃), 50% relative humidity (RH) and packaging in PET bags was presented. The evolution of some key physicochemical and biochemical parameters was studied over a storage period of 90 days. The results obtained in this study indicated that the contents of water and HMF and TBA value in bovine colostrum whey powder packaged in PET bags significantly increased over time during the storage period (P ＜ 0.05) and color difference also showed an increasing trend, even though with some fluctuations, while IgG level conversely exhibited a decreasing trend in the first 60 days, followed by no significant decrease. Under the storage conditions used in this study, the shelf life of bovine colostrum whey powder was 99.40 days. The findings of this study can provide basic data for industrial production of bovine colostrum whey powder.