Researchers led by Shanshan Han and Xiaoyu Wang set out to test whether Astragalus polysaccharides, bioactive macromolecules extracted from the medicinal herb Astragalus membranaceus, could reshape the quality profile of late lactation goat milk in ways that differ from conventional probiotic supplementation. Astragalus polysaccharides, commonly abbreviated APS, have attracted scientific attention for their stability, immunomodulatory properties, and potential metabolic effects. Previous work in heat-stressed dairy cows linked APS intervention to shifts in serum metabolites connected with glucose metabolism, amino acid metabolism, glutathione metabolism, and prolactin signaling, while separate studies reported improved oxidative stability in Cashmere goats receiving Astragalus supplementation. What remained unclear was whether APS could produce coordinated changes in the actual composition of goat milk, spanning everything from bulk nutritional traits to volatile fingerprints and molecular signatures, and whether those changes would look different from what probiotics achieve.

To find out, the team recruited thirty clinically healthy Saanen dairy goats from a commercial farm in Xi’an, China, all in late lactation at roughly 260 days in milk, with balanced parity and baseline milk yields of about 1.2 kilograms per day. Animals with a history of mastitis or recent antibiotic treatment were excluded. After a seven-day acclimatization period, the goats were randomly assigned to two groups of fifteen. One group received a basal total mixed ration top-dressed with five grams per head per day of a composite microbial agent containing Lactobacillus plantarum, Bacillus subtilis, and Saccharomyces cerevisiae. The other received the same ration supplemented with five grams per head per day of feed-grade Astragalus polysaccharide powder with 55 percent polysaccharide purity. The trial ran for thirty days, with milk samples collected at the start and end of the intervention under strict hygienic protocols, snap-frozen in liquid nitrogen, and coded so that analytical personnel remained blind to treatment assignments. All animal procedures followed ARRIVE guidelines and were approved by the Animal Ethics Committee of the Bio-Agriculture Institute of Shaanxi.

The analytical arsenal deployed on these samples was formidable. Conventional composition, including fat, protein, lactose, dry matter, milk urea nitrogen, and somatic cell count, was measured with a CombiFoss FT+ analyzer. Volatile-related sensory profiles were digitized using a PEN3-Plus electronic nose equipped with ten metal oxide semiconductor sensors covering sensitivities to aromatic compounds, nitrogen oxides, sulfur-containing compounds, alkanes, alcohols, and more. The proteome was quantified using data-independent acquisition mass spectrometry on an Orbitrap Astral instrument, with identification controlled at a one percent false discovery rate against the goat protein database. Untargeted metabolomics was performed on an Orbitrap Exploris 480 in both positive and negative ionization modes, while lipidomics employed a Q Exactive mass spectrometer with methyl tert-butyl ether extraction to capture the full lipid repertoire. Supervised multivariate models were rigorously validated with seven-fold cross-validation and two hundred permutation tests to guard against overfitting.

The conventional composition results immediately revealed two divergent response profiles. In the probiotic group, milk fat percentage increased significantly, accompanied by a parallel rise in total solids, suggesting the probiotic effect was largely driven by the fat fraction. Milk urea nitrogen, a widely used indicator of nitrogen utilization efficiency, rose markedly in the probiotic group, a pattern generally associated with less efficient nitrogen use. The APS group told a different story. Milk fat percentage fell significantly relative to baseline, total solids did not increase, and milk urea nitrogen dropped by 6.20 milligrams per deciliter, a reduction the authors interpret as a more favorable nitrogen-use profile. Lactose remained stable in both groups, indicating that the aqueous secretory characteristics of milk were preserved, and protein percentage showed a non-significant upward tendency of 0.42 percent under APS. Somatic cell counts, an indicator of udder health, did not change in either group, providing a stable background against which to interpret the other shifts.

The electronic nose data added a sensory dimension to this divergence. Radar plots of the ten sensor channels showed that the probiotic group’s volatile fingerprint remained broadly similar to its baseline, with only modest expansion. The APS group, by contrast, displayed a pronounced expansion of its sensor response polygon, particularly in the W5S, W2W, and W1S channels, which respond broadly to nitrogen oxide-related compounds, sulfur-containing and aromatic compounds, and methane-related or broad-range volatile classes. Principal component analysis confirmed that APS endpoint samples shifted clearly away from their baseline distribution and formed a distinct cluster, while probiotic endpoint samples stayed closer to the center. Loading analysis identified W5S as the dominant contributor to the separation, and the authors note the intriguing coincidence that lower milk urea nitrogen and a strong W5S response, both nitrogen-related indicators, changed in parallel under APS supplementation.

Proteomic profiling deepened the picture. APS endpoint samples separated clearly from their baselines in principal component space, whereas probiotic samples did not, indicating a stronger proteomic shift under APS. Functional enrichment analysis showed that proteins increased after APS supplementation were annotated mainly to starch and sucrose metabolism, aminoacyl-tRNA biosynthesis, glycolysis and gluconeogenesis, nucleotide metabolism, and sphingolipid signaling pathways, while decreased proteins mapped to cholesterol metabolism and various glycan biosynthesis and degradation pathways. A heatmap of the top fifty differentially abundant proteins revealed two opposing protein modules: a probiotic-associated module containing fibrinogen gamma chain, complement component 9, lipoprotein lipase, and other extracellular matrix and immune-related proteins, and an APS-associated module enriched in heat shock protein 90 beta, calreticulin, protein disulfide isomerases, calnexin, asparagine synthetase, and glycolytic enzymes such as lactate dehydrogenase A and glyceraldehyde-3-phosphate dehydrogenase.

Targeted inspection of lipid metabolism proteins sharpened the APS signature further. Compared with baseline, the APS group showed elevated abundance of acetyl-CoA carboxylase alpha, fatty acid synthase, and ATP citrate lyase, with fold changes of 1.49, 1.70, and 2.52 respectively, enzymes central to acetyl-CoA supply, malonyl-CoA formation, and fatty acid biosynthesis. NADPH-generating enzymes, including isocitrate dehydrogenase 1, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase, also rose, with the latter two increasing more than two-fold, providing the reducing equivalents that lipid biosynthesis demands. Meanwhile lipoprotein lipase abundance fell dramatically to 0.26 of baseline, suggesting a redistribution of lipid-processing capacity rather than a blanket increase. The probiotic group showed only mild changes in the same protein set, reinforcing the distinctness of the APS response.

The metabolomic and lipidomic layers completed the molecular portrait. Untargeted metabolomics identified 904 differential metabolites in the APS group versus 587 in the probiotic group, with lipid-related metabolites and organic acids, including tricarboxylic acid cycle intermediates such as citrate and malate, among the prominent responsive categories. Lipidomic profiling detected 2,553 lipid molecules spanning 42 subclasses, with triacylglycerols dominating at more than 88 percent of total lipid signal as expected for mammalian milk. Within that architecture, APS supplementation was associated with a 1.12-fold increase in total triacylglycerol signal, enrichment of medium-chain triacylglycerol species containing C6:0, C8:0, and C10:0 acyl groups, which are characteristic contributors to goat milk flavor after lipolysis, and a coordinated remodeling of polar lipids. Phosphatidylethanolamine and phosphatidylcholine, major components of the milk fat globule membrane, increased approximately 1.4-fold and 1.5-fold respectively, while ceramide rose nearly five-fold and sphingomyelin declined, an inverse pattern the authors interpret as sphingolipid compositional remodeling within the milk matrix.

Finally, an integrated correlation network linking proteins, lipids, metabolites, and electronic nose responses tied the layers together. Glucose-6-phosphate dehydrogenase and fatty acid synthase correlated strongly and positively with phosphatidylethanolamine- and ceramide-related lipid features, with correlation coefficients exceeding 0.85, while lipoprotein lipase was strongly negatively correlated with a specific ceramide species at r equal to minus 0.96. Strikingly, the ether-linked phosphatidylcholine species PC(18:0e/22:4) and an oxidized ceramide were positively correlated with W5S- and W2W-related sensor responses at r equal to 0.83, connecting milk polar lipid chemistry directly to volatile-related sensor signals. The authors are careful to frame these findings as association-based and hypothesis-generating rather than causal proof, noting the absence of an untreated control group, the use of milk rather than mammary tissue, and the sensor-level rather than compound-level nature of electronic nose data. Even so, the coherent multi-omics signature, spanning reduced milk urea nitrogen, a distinct volatile fingerprint, enriched lipid-synthesis proteins, and selective remodeling of medium-chain triacylglycerols, membrane phospholipids, and sphingolipids, positions Astragalus polysaccharide as a promising plant-derived, non-microbial nutritional strategy for stabilizing goat milk quality precisely when the industry needs it most.

Subject of Research: Multi-omics analysis of milk quality responses to Astragalus polysaccharide supplementation in late lactation dairy goats

Article Title: Milk-based multi-omics reveals distinct quality signatures associated with Astragalus polysaccharide supplementation in late lactation goats

Article References: Han, S., Wang, P., Hu, Y., Zhang, Q., Wan, K., & Wang, X. (2026). Milk-based multi-omics reveals distinct quality signatures associated with Astragalus polysaccharide supplementation in late lactation goats. Food Chemistry: X, 39, Article 104395. https://doi.org/10.1016/j.fochx.2026.104395

Image Credits: AI Generated

DOI: Not provided

Keywords: goat milk, Astragalus polysaccharide, late lactation, multi-omics, proteomics, metabolomics, lipidomics, electronic nose, milk urea nitrogen, milk fat globule membrane, probiotics, dairy quality

The team focused on three iconic Korean fermented soybean products: cheonggukjang, doenjang, and meju. Although all three begin with boiled soybeans, they diverge dramatically in their fermentation conditions, microbial communities, and resulting chemistry. Cheonggukjang is fermented briefly and with little salt, allowing Bacillus species to dominate. Doenjang undergoes prolonged maturation in a high-salt environment that reshapes its microbial ecology. Meju, the fermented soybean brick that serves as the foundation for both doenjang and soy sauce, is dominated by fungi such as Aspergillus species and is rich in the enzymes and metabolites those microbes generate. Because these pastes are known to contain bioactive compounds with antioxidant, anti-inflammatory, and immunomodulatory properties, the researchers reasoned that their extracts might act as functional starter ingredients rather than mere flavorings.

To test the idea, the scientists prepared extract solutions from commercially purchased cheonggukjang, doenjang, and meju by diluting each paste 1:100 in distilled water, then centrifuging and filtering the mixture. Each extract was inoculated at 0.5 percent by volume into 400 milliliters of milk cream. A control butter was fermented with a commercial starter containing Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. All creams were fermented at 37 degrees Celsius for 24 hours, aged at 4 degrees Celsius for 12 hours, and then churned at 280 revolutions per minute for 15 minutes. The resulting butters were subjected to a battery of analyses covering pH, color, viscosity, moisture and fat content, microbial counts, electronic nose and electronic tongue profiling, and a sensory evaluation by a sixteen-member trained panel.

The pH results immediately revealed a fundamental biochemical divide. Butters fermented with the soy paste extracts had significantly higher pH values than the control, with the cheonggukjang sample highest of all. The explanation lies in the contrasting metabolisms of the microbial communities involved. Commercial lactic acid starter cultures flood the cream with lactic acid early in fermentation, driving pH down. The mixed communities drawn from traditional pastes, by contrast, include fungi and Bacillus species that decompose proteins and deaminate amino acids, releasing ammonia and other alkaline metabolites that push pH upward. The authors suggest this milder acidity may actually benefit the product, reducing sourness while allowing flavor-producing microbes to remain metabolically active, potentially enhancing both flavor quality and the delivery of probiotic organisms.

Physical properties told a reassuring story for manufacturers. Viscosity showed no significant differences among any of the butters, treated or control. Butter’s high-fat water-in-oil matrix provides substantial emulsification stability, and the small quantities of microbial metabolites generated during fermentation were simply not enough to alter its flow behavior. This means soy paste extracts can be incorporated without compromising the texture consumers expect. Color, however, did change: the meju and cheonggukjang butters were significantly more yellow than the control and the doenjang butter. Bacillus species abundant in these pastes produce peptides, free amino acids, and Maillard reaction products during fermentation, while molds and yeasts can promote browning reactions between reducing sugars and amino acids. The yellowness matters commercially, because previous research has shown that consumers associate a deeper golden hue in butter with higher purchase intention.

Microbial counts exposed the most striking differences. Total plate counts were significantly higher in all three extract-fermented butters than in the control, with cheonggukjang butter highest, reflecting its Bacillus-rich, low-salt, short-fermentation origin. Lactic acid bacteria counts were also elevated in all treated samples, but here meju butter took the lead. The researchers attribute this to Aspergillus oryzae, the fungus central to meju fermentation, whose powerful enzymes break proteins and carbohydrates into low-molecular-weight compounds that effectively feed lactic acid bacteria. Meju-derived communities also showed greater tolerance and adaptability to environmental stress than freeze-dried commercial strains. The doenjang-derived bacteria, adapted to high-salt conditions, grew more slowly in butter’s low-salt, high-fat environment, while cheonggukjang organisms, adapted to high water activity, were similarly constrained in the low-moisture product.

The flavor chemistry was mapped with an electronic nose, which identified elevated levels of volatile compounds including trimethylamine, ethanethiol, ethyl acetate, 2-methylbutanal, 3-methyl-1-butanol, and propyl acetate in the extract-fermented butters. Ethyl acetate, associated with buttery and fermented notes, was markedly higher in the meju butter. Principal component analysis of the aroma data achieved a discrimination index of 88, with the first principal component alone explaining 97.4 percent of the variance, cleanly separating the control from the treated samples and distinguishing the treated samples from one another. Notably, the sulfurous, rancid, and beany flavors often associated with fermented soybean products were not detected in the finished butter, suggesting the extracts can contribute desirable fermented aromas without importing off-flavors.

The electronic tongue added a taste dimension. Extract-fermented butters scored higher than the control in sourness, saltiness, and umami. The elevated sourness tracked with lactic acid bacteria counts, since more bacteria meant more organic acids. Saltiness was highest in the doenjang butter, consistent with residual salts carried over from its brine-fermented origin. Umami, measured against a monosodium glutamate reference, was highest in the meju butter, reflecting its greater content of glutamic acid, small peptides, and nucleotides released by the proteolytic activity of Aspergillus and Bacillus enzymes. Interestingly, the taste-based principal component analysis showed minimal differences among the three treated butters, indicating that despite their different origins, the pastes share overlapping microbial communities and metabolite profiles that converge in the finished dairy matrix.

The sensory panel delivered the verdict that matters most to consumers. The meju butter scored highest in flavor, taste, absence of off-flavor, and overall acceptability, and together with the cheonggukjang butter earned the top appearance scores, mirroring the color measurements. Panelists rated all extract-fermented butters higher than the control for texture attributes, likely because metabolites such as melanoidins, polyphenols, and peptides disperse within the fat matrix and moderate greasiness. The authors caution that their extracts contained both microorganisms and metabolites, so the observed effects reflect their combined action, and further microbiological work will be needed to separate the two. Still, the conclusion is clear: meju extract in particular can meaningfully improve the quality, microbial profile, and sensory appeal of fermented butter. As demand grows for dairy products that offer health benefits beyond basic nutrition, this study suggests that centuries-old Korean fermentation wisdom may have a place on the modern breakfast table, one golden, umami-rich pat at a time.

Subject of Research: Use of Korean traditional fermented soy paste extracts as starter ingredients to improve the quality and sensory properties of fermented butter

Article Title: Quality properties of fermented butter using extract solution from Korean traditional fermented pastes

Article References: Jeong, Y.-S., Yong, H. I., & Park, S.-Y. (2026). Quality properties of fermented butter using extract solution from Korean traditional fermented pastes. Food Science of Animal Resources, 46(1), Article 92. https://doi.org/10.1007/s44463-026-00089-2

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00089-2

Keywords: fermented butter, Korean fermented soy paste, meju, doenjang, cheonggukjang, lactic acid bacteria, electronic nose, electronic tongue, sensory evaluation, food fermentation, dairy quality, umami