International Dairy Journal最新文献

{"title":"Investigation of various AprX endopeptidases in milk: heat stability, substrate selectivity and a novel sample preparation method for subsequent detection","authors":"Veronika Volk,&nbsp;Timo Stressler,&nbsp;Lutz Fischer","doi":"10.1016/j.idairyj.2025.106353","DOIUrl":"10.1016/j.idairyj.2025.106353","url":null,"abstract":"<div><div>AprX, metallopeptidases secreted by <em>Pseudomonas</em> spp. in milk, are described for their heat stability, especially during UHT treatments. Thus, they are described for their involvement in protein destabilization of shelf-stable milk products. Results showed temperature inactivation at 55 °C enhanced inactivation of most AprX compared to other temperatures. Further, AprX's half-life at 55 °C was 7.7–14.4 min. Substrate selectivity from eight <em>Pseudomonas</em> AprX was investigated using <em>para</em>-nitroaniline-substrates. The preference for Arg or Ala at P1-position at the cleavage site was linked to the AprX sequence identity. Shelf-life experiments at 20 °C determined a critical endopeptidase activity threshold of 0.1 pkat mL⁻¹ correlated with the protein destabilization for three months. Detection of such low endopeptidase activities requires a sample preparation and concentration method, which was developed. The two-step preparation method removed milk proteins and concentrated AprX 10-fold allowing a 60 ± 0.3 % recovery and precise quantification (coefficient of variation: 8.51 %).</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106353"},"PeriodicalIF":3.1,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144634020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional and technological effects of CLA-producing lactic acid bacteria in Minas Frescal cheese: Toward probiotic dairy innovation","authors":"Paulo Henrique Lima Fernandes ,&nbsp;Katherine Gutiérrez-Álzate ,&nbsp;Carla Paulo Vieira ,&nbsp;Bruna Samara dos Santos Rekowsky ,&nbsp;Leonardo Fonseca Maciel ,&nbsp;Iuri Lima dos Santos Rosario ,&nbsp;Marion Pereira da Costa","doi":"10.1016/j.idairyj.2025.106348","DOIUrl":"10.1016/j.idairyj.2025.106348","url":null,"abstract":"<div><div>Consumer demand for healthier food options has sparked interest in conjugated linoleic acid (CLA) due to its potential health benefits. Dairy products naturally contain CLA, but levels often require enhancement. This study aims to identify CLA-producing bacteria and assess their efficacy in producing Minas Frescal cheese naturally enriched with CLA. We identified four CLA-producing bacterial strains from MRS broth, using three to create four cheese treatments: a control group (TTC) and three groups inoculated, respectively, with <em>Lactococcus lactis</em> subsp<em>. lactis</em> LL (TLL), <em>Lacticaseibacillus rhamnosus</em> LR (TLR), and <em>Pediococcus pentosaceus</em> PP (TPP). Analyses of proximate composition, pH, microbiology, and fatty acids showed that the cheeses met semi-fat criteria. Bacterial strains affected cheese characteristics like fat content, pH, color, and texture. While the study found that <em>Lactococcus lactis</em> subsp. <em>lactis</em> LL, <em>Lacticaseibacillus rhamnosus</em> LR, and <em>Pediococcus pentosaceus</em> PP cultures did not significantly enhance conjugated linoleic acid (CLA) levels in Minas Frescal cheese, it underscored their role in shaping the texture, color, and microbiota. These effects may directly influence the sensory attributes and microbiological stability of the cheese. Notably, TLL and TPP cheeses exhibited elevated counts of lactic acid bacteria, suggesting potential probiotic benefits. Moreover, the incorporation of <em>Pediococcus pentosaceus</em> PP represents an innovative strategy in dairy industry, contributing to the development of functional dairy products with enhanced health-promoting properties.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106348"},"PeriodicalIF":3.1,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Milk gel formation and properties: impact of whey protein aggregates","authors":"Erik Juste,&nbsp;Jeehyun Lee,&nbsp;Thomas Croguennec","doi":"10.1016/j.idairyj.2025.106354","DOIUrl":"10.1016/j.idairyj.2025.106354","url":null,"abstract":"<div><div>Whey protein aggregation has been used in cheesemaking to increase the yield. This review examines rennet- and acid-induced milk gelation in the presence of whey protein aggregates. <em>In situ</em> aggregates, formed during milk heating, impair enzymatic gelation by hindering casein micelle aggregation but enhance acid gel strength. <em>Ex situ</em> aggregates, pre-formed and added in milk, exhibit various morphologies. They alter gelation dynamics and gel properties differently compared to <em>in situ</em> aggregates. However, this research area remains highly underexplored. Physics-based models may give insights on underlying mechanisms of gel formation but lack specificity for casein micelle dynamics and show limits in integrating whey protein aggregates. Future research must prioritise mechanistic insights into interactions between whey protein aggregates and casein micelles. Such advances could optimise <em>ex situ</em> aggregates structure and properties for innovative cheesemaking, balancing texture, nutrition and yield.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106354"},"PeriodicalIF":3.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144634019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of minor β-CN genotypes on coagulation properties and proteolytic pathways of bovine milk","authors":"Nan Gai ,&nbsp;Therese Uniacke-Lowe ,&nbsp;David A. Goulding ,&nbsp;Jonathan O'Regan ,&nbsp;Michael Affolter ,&nbsp;Alan L. Kelly","doi":"10.1016/j.idairyj.2025.106352","DOIUrl":"10.1016/j.idairyj.2025.106352","url":null,"abstract":"<div><div>Numerous studies have examined the effects of the two most common β-casein (β-CN) genetic variants, A1 and A2, on the physicochemical and functional properties of bovine milk. However, relatively minor variants of this protein such as B and I remain under-researched. This study collected milk with four β-CN genotypes, A1B, A2B, A1I, and A2I, across three collection occasions to investigate their functional and proteolytic properties. Milk of the B variant exhibited similar behaviour to A1 regarding rennet and acid coagulation properties, while I was similar to A2. Furthermore, the Glu₁₂₁-Arg₁₂₂ and Arg₁₂₂-Gln₁₂₃ bonds in the β-CN B variant were more sensitive to plasmin-derived proteolysis than Ser₁₂₂ in other variants, leading to more peptides from cleavage at Arg₁₂₂-related sites. These findings support grouping genotypes based on the amino acid (AA) at position 67, as variants sharing the same AA at this position exhibit similar processability, while also highlighting the significant impact of AA at position 122 for proteolysis in milk or dairy products.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106352"},"PeriodicalIF":3.1,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-based identification, and characterization of a bacteriocin selective inhibiting Penicillium citrinum in yak yogurt","authors":"Yongqi Yang ,&nbsp;Huojian Zheng ,&nbsp;Cancan Qi ,&nbsp;Qin Wang ,&nbsp;Rodrigo Ledesma-Amaro ,&nbsp;Liping Wang","doi":"10.1016/j.idairyj.2025.106351","DOIUrl":"10.1016/j.idairyj.2025.106351","url":null,"abstract":"<div><div>This study purified, identified, and characterized SN-F1, a novel bacteriocin produced by <em>Limosilactobacillus fermentum</em> SN-1 isolated from traditional Qinghai yak yogurt. SN-F1 was extracted using ethyl acetate and purified through multistep chromatography (cation-exchange, gel filtration, and semi-preparative RP-HPLC). Tricine-SDS-PAGE and HPLC-MS/MS analysis revealed SN-F1 has a molecular mass of 2859.29 Da and a novel sequence (NINDQWLVLSSTQAAKLQALMKDVTA), classifying it as a class II bacteriocin. SN-F1 exhibited broad-spectrum antimicrobial activity, inhibiting the key dairy spoilage mold <em>Penicillium citrinum</em> GLM6, various Gram-positive and Gram-negative foodborne pathogens, and several yeasts. The bacteriocin demonstrated significant thermostability (retained activity after 121 °C for 20 min) and high stability across a wide pH range (pH 2–8), but was completely inactivated by proteases (trypsin, protease K, papain, pepsin, flavor protease). Molecular docking elucidated the interaction forces and specific binding sites between SN-F1 and target cell membrane proteins. Crucially, incorporating SN-F1-producing <em>L. fermentum</em> SN-1 into fermentations with other functional lactic acid bacteria successfully produced enhanced traditional dairy products, confirming SN-F1's effective antibacterial activity.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"170 ","pages":"Article 106351"},"PeriodicalIF":3.1,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urbanization and seasonal effects on dairy cow diets and milk fatty acid profiles in the Indian Megacity of Bengaluru","authors":"Shahin Alam ,&nbsp;Silpa Mullakkalparambil Velayudhan ,&nbsp;Regina Roessler ,&nbsp;Tong Yin ,&nbsp;Sivashanmugam Parthipan ,&nbsp;Anjumoni Mech ,&nbsp;Nira Manik Soren ,&nbsp;Pradeep Kumar Malik ,&nbsp;Somu Bala Nageswara Rao ,&nbsp;Raghavendra Bhatta ,&nbsp;Sven König ,&nbsp;Eva Schlecht","doi":"10.1016/j.idairyj.2025.106343","DOIUrl":"10.1016/j.idairyj.2025.106343","url":null,"abstract":"<div><div>To explore urbanization effects on milk fatty acid (FA) profile, 39 farmers from urban and peri-urban locations in Bengaluru, southern India, were visited during three seasons. Individual cow data was collected on breed, milk yield and quality, as well as diet composition in winter 2021 (n = 74), monsoon 2021 (n = 61), and summer season 2022 (n = 104). Location within the city and season affected milk yield, with highest values recorded for urban locations and winter. Milk fat content and FA profiles also varied between locations and seasons, with milk from urban cows containing more linoleic (36 %), n-3 (40 %), n-6 (35 %), and unsaturated (11 %) FA than milk from peri-urban cows. Winter season milk had the highest concentrations of linoleic (19 %) and n-6 (17 %) FA, whereas summer season milk contained more oleic (7 %) and unsaturated (5 %) FA. The results suggest that the alternative feedstuffs used by land-constrained farmers are capable of yielding a high-quality product for consumers.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"170 ","pages":"Article 106343"},"PeriodicalIF":3.1,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144657113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of powdering process of low-heat skim milk powder on rennet-induced gelation and syneresis behaviour","authors":"Wataru Ono ,&nbsp;Hiroki Ando ,&nbsp;Minamo Hayashi ,&nbsp;Kouki Onuma ,&nbsp;Daiki Oka ,&nbsp;Tomohiro Noguchi","doi":"10.1016/j.idairyj.2025.106345","DOIUrl":"10.1016/j.idairyj.2025.106345","url":null,"abstract":"<div><div>Reconstituted low-heat skim milk powder (SMP) exhibits rennet-induced gelation. Although it is known that the gelling properties of reconstituted SMP are poorer than those of preheated milk, the cause has not yet been identified. In this study, we analysed the denatured proteins, soluble calcium, rennet-induced gelation, and syneresis properties of skim milk subjected to preheating, concentration, and spray drying. Furthermore, the effects of the denatured proteins and decrease in soluble calcium caused by concentration and spray drying on gelling and syneresis properties were investigated using ultrafiltrate or simulated milk ultrafiltrate. The reduction in gelling and syneresis properties was found to be caused by a decrease in soluble calcium following the concentration. Our results also indicate that slight denaturation of whey proteins caused by concentration and spray drying had little effect on the gelling and syneresis properties. These findings provide important insights for the use of SMP in the dairy industry.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106345"},"PeriodicalIF":3.1,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of milk derived oligosaccharides from whey permeate for use in infant milk formula","authors":"Ger Ryan,&nbsp;Amie Woods,&nbsp;Jonathan O'Regan","doi":"10.1016/j.idairyj.2025.106350","DOIUrl":"10.1016/j.idairyj.2025.106350","url":null,"abstract":"<div><div>The nutritional profile of a milk oligosaccharides (MOS) ingredient, derived from whey permeate, was assessed compared to a galacto-oligosaccharides (GOS) ingredient, produced from purified lactose. Significantly higher (<em>P</em> &lt; 0.05) levels of 3′-sialyllactose (3′-SL) and 6′-sialyllactose (6′-SL) were present in MOS due to its sourcing from whey permeate compared to the GOS ingredient. MOS also contained higher levels of protein, minerals, vitamins and other nutritional components compared to the GOS ingredient. MOS displayed lower levels of GOS and higher levels of lactose, glucose and galactose than the GOS ingredient due to differences in manufacturing conditions. A model infant milk formula (IMF) containing MOS displayed significantly higher (<em>P</em> &lt; 0.05) levels of 3′-SL and 6′-SL compared to IMF containing the GOS ingredient. These sialylated oligosaccharides contribute to the more complex structural diversity of MOS compared to GOS, thereby potentially supporting reported microbiota and immune benefits for infants.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106350"},"PeriodicalIF":3.1,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of Vitamin C degradation and browning index of enriched heat-treated yogurt milk","authors":"Carolina Neves Cunha ,&nbsp;Caroline Barroso dos Anjos Pinto ,&nbsp;Maria Esther Leal da Silva Sad ,&nbsp;Rodrigo Stephani ,&nbsp;Alan Wolfschoon Pombo ,&nbsp;Juliana de Carvalho da Costa ,&nbsp;Ítalo Tuler Perrone","doi":"10.1016/j.idairyj.2025.106349","DOIUrl":"10.1016/j.idairyj.2025.106349","url":null,"abstract":"<div><div>The dairy industry has been developing products enriched with vitamin C, mainly yogurts, to meet consumer demand for products associated with improved immunity. However, its potential degradation before the end of the shelf life could provide the consumer with a vitamin content different from what is stated on the label, in addition to amplifying browning phenomena. To test this hypothesis, this study aimed to determine the degradation kinetics of vitamin C in yogurt and correlate its degradation with browning reactions. High-performance liquid chromatography (HPLC) was used to quantify vitamin C and markers of the Maillard reaction (MR). Vitamin C was monitored over a 21-day storage period at 7 ± 2 °C, and a first-order reaction kinetic model best described its decrease. A loss of 73.9 %–78.7 % of vitamin C was observed, along with an intensification of the browning reaction by the end of the storage period.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106349"},"PeriodicalIF":3.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of encapsulated bovine milk exosome microcapsules and their resistance to environmental stability","authors":"Aili Li ,&nbsp;Jingwen Zhao ,&nbsp;Sufang Duan ,&nbsp;Yumeng Zhang ,&nbsp;Jian He ,&nbsp;Wei Yu","doi":"10.1016/j.idairyj.2025.106347","DOIUrl":"10.1016/j.idairyj.2025.106347","url":null,"abstract":"<div><div>Bovine milk exosomes (BME) have great potential for application in food and medicine due to their functional activities, such as immunomodulation and antioxidants. Still, their lack of stability in processing, storage, and digestive environments seriously restricts industrialization. In this study, sodium alginate (SA) and guar gum (GG) were used as wall materials to construct a BME microencapsulation system with a protective effect by the calcium ion cross-linking method. The optimized embedding parameters were determined by response surface methodology as 0.5 % w/v for GG, 1.5 % w/v for SA, and 4 % for CaCl₂, which achieved an encapsulation efficiency rate of 91.32 ± 0.32 %. Characterization results showed that the SA-GG-BME microcapsules had a dense network structure, and the microcapsules exhibited excellent water-holding and textural properties as well as pH-responsive swelling properties. Inverse experiments showed that SA-GG-BME microcapsules significantly improved stability compared with free-bovine milk exosomes (Free-BME): protein and RNA retention were 75 % and 45 % after simulated <em>in vitro</em> gastrointestinal digestion for 6 h, Macrophage metabolic activity reached 145.19 ± 0.42 % in the heat-treated group at 65 °C/30 min (vs. 137.50 ± 0.73 % in the free group, <em>P</em> &lt; 0.05), and the SA-GG-BME microcapsules exhibited excellent water holding properties and pH-responsive swelling properties after storage at 4 °C for 28 d. The microcapsules had a dense network structure. After 28 d of storage at 4 °C, the active components in the SA-GG-BME group were 12–14 times higher than those in the Free-BME group. The macrophage-promoting metabolic activity (120.37 ± 0.57 %) was significantly better than that of the SA-BME group (105.09 ± 0.73 %) vs. the Free-BME group (inactive) (<em>P</em> &lt; 0.05). By revealing the hydrogen bonding-hydrophobic synergistic protection mechanism of SA-GG wall materials, the present study provides a theoretical basis for applying BME in functional dairy products and orally targeted formulations.</div></div>","PeriodicalId":13854,"journal":{"name":"International Dairy Journal","volume":"169 ","pages":"Article 106347"},"PeriodicalIF":3.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}